US2663128A - Method and machine for making capsules - Google Patents

Description

Dec. 22, 1953 F. E. sTlRN ETAL METHOD AND MACHINE FOR MAKING CAPSULES 6 Sheets-Sheet l Filed March 23, 1948 ATTORNEY Dec. 22, 1953 F. E. sTlRN ETA.

METHOD AND MACHINE FOR MAKING CAPSULES 6 Sheets-Sheet 2 Filed March 23, 1948 q/PTHUP J 7147/40?,

ATTORNEY Dec. 22, 1953 F. E. sTlRN ETAL METHOD AND MACHINE FOR MAKING CAPSULES 6 Sheets-Sheet 3 Filed March 25, 1948 lNvENToRs nF4/wr f. Jr//F/v wwwa/P 6. 714,0 af?,

BY MM 7F40 ATTORNEY Dec. 22, 1953 F. E. sTlRN ETAL 2,663,128

l METHOD AND MACHINE FOR MAKING CAPSULES Filed March 2s, 1948 e sheets-sheet 4 INVENTORS F/P/Y/f f. ST/F/V www# ATTORNEY Dec. 22, 1953 F. E, sTlRN ET AL f 2,663,128

' METHOD AND MACHINE FOR MAKING CAPSULES Filed March 23, 1948 6 Sheets-Sheet 5 i i 64 u 55 l 5.? Y

AP75 l" f7 .58'

` ATTORNEY Dec- 22, 1953 F. E. sTlRN ET AL 2,663,128

METHOD AND MACHINE FOR MAKING CAPSULES Filed March 23, 1948 6 Sheets-Sheet 6 mvENToRs #w24/mf f. f77/Pw, smv/WMP@ nef/z of?,

ATTORNEY Patented Dec. 22, 1953 Frank E. Stirn, learl River, and Arthur S. Taylor, Spring Valley, N. Y., assignors to American Cyanamid Company, New York, N. Y., a corporation of Maine I Application March 23, 1948, Serial N o. 16,5154

16 claims. (ci. 53-5) Our invention', relates to improvements in a mechanism for forming and lling capsules from a deformable strip material.

The invention relates in essenceto improvements in a type` of Amechanism where capsules are formed and lled as a. continuous process. It'includes as integral'parts, both the machine and method whereby a plastic material is cast on a castingroll or surface in its liquid state, treated so as to become plastic and form a web capableY of supporting and maintaining itself, stripping the web, treating the surfaces of the web soas to cause them to stick where desired, not to stickiwhere desired, coloring' them where desired, deforming certain portions of the strip to selected forms,sealing 'another portion of the strip over the Vfilled portion in such a manner that the iinal capsule will have the desired form, removing the iilled capsule v,from the web and delivering and treating the capsules. By means of our` invention it is possible to'form and ll capsules with accurately measured doses of varous types of material. A particularly kimpor- 'tant phase of this invention is a mechanism and method whereby powders may be filled into soft gelatin capsules in therapeutically desirable doses readily, eiciently and cheaply. e y

Subject material related to that herein disclosed is claimed in divisional applications, Serial No. 351,106, entitled Method and Apparatus for Filling Capsules, Serial No. 351,107, entitled Capsule` 'Forming Gelatin Strip Handling, and Serial No. 351,108,7entitled Capsule Forming Gelatin Film Stripping, all led April 27, 1953. Related details of a die roll structure are described and claimed in Serial No. 164,426, filed May 26, 1950, entitled-Method and Apparatus for Forming Combination-Filled Capsules.

An important object of our invention is a method of forming essentially symmetrical capsules from essentially non-symmetrical dies by so treating the web and conditioning the film from which the capsules are formed that the cut-out capsule stretches, shrinks and forms itself into the desired shape, which shape is related to but is notuthe sameas'that of the die members. In one modification of thisndevice the die members form a substantially cylindrical capsule', the joining linerof which is a 'circle forming one end of the cylinder, and which upon release'forms a capsule of substantially spheroidal form with the yjoining line substantially equatorial. Y

`An additional object of our invention is a method vto form symmetrical capsules :'.with asymmetric dies.

A further object of our invention is to form spheroidal gelatin capsules with mating dies, one of which is substantially cylindrical inform.

A still further object. of ourfinvention is to pretreat gelatin lms so that different portions of a formed capsule will have diierent plastic characteristics so that upon release from its die mold the capsule will naturally form itself to the desired configuration. Further objects, advantages and meritorious features will appear from the following description, appended claims and accompanying drawings.

Figure 1 is a side elevation of a particular form of an apparatus embodying the present invention. y

Figure 2 is a rear elevation showing more particularly certain of the drive mechanisms for the various gears,v cams and rollers.

Figure 3 is a pictorial view showing the paths of the plastic strips as they pass through the machine.

Figure 4 is a top view of the sealing lm turnover mechanism.

Figure5 is an elevation of a portion of the die roll'structure showing temperature control elements and the positioning mechanism of the illing heads,

Figure 6 is a front view of the statorcf the cavity die roll, showing the pressure and vacuum chests, heat control, etc.

Figure 6a is a side view of the stator.

Figure 7 is an enlarged view of a single die of the die roll and its cooperating filling head.

Figure 8 is a pictorial view of a lling head.

Figure 9 is a view showing the various coordinated phases of the die wheel operation.

Figure lois a fragmentary view on an enlarged scale taken along the line I -I 0 of Figure 9, showing the lower film in position over the die cavity.

Figure 11 is a similar view along the line II-II of Figure 9 showing the die cavity containing the deformed lower lm with the filling head in lling position as the powder ilows into the cavity. j l

Figure 12 is asimilar view along the line |2--l2 of Figure 9 showing the filled individual cavity as the uppersealing film is positioned thereover.

Figure 13 is a similar view along the line I3-l3 of Figure 9 showing the joining and cutting out of portions of the two lmsto form the individual capsule.

Figure 14, along the line Ill- I4 of Figure 9,

1 shows the air ejector mechanism whereby the capsule is ejected from its mold, showing more particularly how the capsule rounds out as it is ejected, forming with a substantially equatorial joining line.

This improved apparatus is designed to rapidly and efciently produce capsules of consistent size. In the past it has been common to produce soft gelatin capsules lled With liquid or with pastes. Ii solids were to be encapsulated, such solids were dispersed in a liquid to form a paste so that the materials could be lled on the then existent machines.

With the development of purer and more potent vitamin products, the use of materials such as sh liver oil has given way to the' use of more constituents of Vitamin capsules in solid form. Many of the vitamins are now obtainable or may be converted to a particulate form, and their use in a powdered form possesses certain conveniences and therapeutical advantages, the full commercialization of which has been handicapped by the lack of a suitable encapsulating machine.

The use of powders has long been known in hard gelatin capsules, in which the capsule body is rst formed, then lled, and then a cap placed thereupon. The prior art has been uniformly unsuccessful in producing satisfactory, adequate, and cheap machines for the lling of powders into soft gelatin capsules. Our machine lls the need. It will rapidly, easily and accurately form such powder iilled capsules. This machine can be readily and conveniently adapted to ll liquids or pastes or can be used with iilmsy of material other than geltain, if such materials are plastic, are capable of being formed into films, and if such lms will unite with each other when passed through sealing rolls. v

More particularly, in our machine, molten gelatin as described below, is prepared and fed into the hopper 2 i. For temperature control it is desirable that the hopper be equipped with a termostatically controlled heater element 2Ihl so that the gelatin may be kept at a desired temperature. If the hopper is constructed of brass the heat conductivity of the material will enable the heat to be applied at 'one location, as shown in Figure l. If other materials of construction are used, a more uniform distribution of heat over its surface may be desirable. A jacketed hopper may be used with a suitable fluid heat transfer medium. The hopper 2l may be lled by a gelatin supply line 22 connected to a suitable source by which the gelatin in the hopper is maintained at a reasonably uniform level. The gelatin hopper may be equipped with a transparent plastic top or itself be of transparent materials in order that the gelatin level may be observed, but yet maintained free from danger of contamination, and from loss of volatile constituents. The gelatin feeds through the hopper under a doctor blade 23. The gelatin doctor blade may be separate or formed integral with the hopper, which may ride on the surface of the casting wheel 24, which wheel is formed preferably from a metal such as cast iron which should be given a highly polished surface, as for example by chrome plating. The hopper with the attached doctor blade is Preferably adjustably locatable .by means of links 25 and 23 and adjustable shoes or rollers 2 is, riding on the surface of the casting roll soy that the thickness of the gelatin lm may be conveniently regulated. The hopper may be rigid if the doctor blade floats in the desired relationship to the druml surface.

The doctor blade may be. divided vertically in the center and each division made independently adjustable so that two separate thicknesses of film may be cast at the same time so that the two diierent lms will each be of independently adjustable thickness. This individual adjustability is of value in adjusting the position of the equatorial seal and in insuring that the wall thickness of the diierent portions of the capsule will be in accordance with the operators desires.

The gelatin lm is split into two portions by a splitting roll 21 which is a reasonably sharp rotatable knife, spring loaded by an adjustable spring mechanism 28 so as to separate the cast film into two separate strips. The splitting roll may be located adjacent to the gelatin hopper as shownx or may be located further around the casting wheel. It is only necessary that the gelatin nlm be somewhat solid at the splitting point, so that the gelatin will not ilow back together after being split.

The entire mechanism is best located in an air conditioned room so that both temperature and humidity may be controlled so as to maintain the gelatin lm in the desired condition throughout. The casting wheel is covered with a shield 29 which is located so that it is adjacent to but does not interfere with the rotation of the wheel. An exhaust duct 30 is provided through which the air is exhausted so that dry conditioned air from the room is pulled through the casting wheel shield 29 where it driesV and conditions the surface of the gelatin film, and is exhausted either into the room or an exhaust duct, depending upon moisture load conditions. The casting wheel is suitably supported from a main frame 3l and driven in suitably timed relationship with the rest of the mechanism by a mechanical drive means.

The partially dried and conditioned gelatin strip is removed from the casting wheel by a stripper paddle 33. The stripper paddle is driven by a belt or other suitable drive at a faster speed than. the peripheral. speed of the casting wheel so as to pull off the gelatin lm by its action. The repeated soft blows4 of the leading edges of this paddle as the paddle is rotated has a tendency to strip the gelatin lm Without damaging or stretching the lm. It is highly advantageous in the production of spherical capsules that the gelatin film be not stretched.A

Under certain operating Aconditions as is later described, it is desired to stretch markedly the gelatin lm by keeping it under tension, and forming the capsule While under tension. Under such conditions, a stripping roll may be substituted for the paddle. When so formed the gelatin strip material attempts to pull back to its original shape to relieve the strain and accordingly, elliptical capsules. are produced from round molds.k If elliptical shaped capsules are desired, they may be produced in round dies by prestretching the lm. Under the normal relationships, where it is desired that a round die cut a round capsule, it is accordingly equally desirable that the gelatin lrn. be not stretched and remain substantially isotropic, so that the nished capsule will retain the desired shape.

As. shown particularly clearly in Figure 3, the twov gelatin strips take separate paths from the stripper paddle. The sealing lm 34 goes above the die roll and may be supported over guide rolls 35 and 36 on which may be placed a carrier belt 31. The carrier belt and rollers should be of a material which will not stick to the gelatin. It iS Possible and frequently convenient to use rolls made from "Teflon (polytetrafluoroethylene,l see vU. S. Patent No."2,230,654' to Plunkett) or from sintered metals which are fed with an oiler to form oiled surfaces to which the gelatin strip will not adhere. If several rollers are used, a carrier belt isnot necessary.

After passing over these guide members `the strip itself is fed under and over a. turnover mechanism 38. It has been found that for the gelatin sealing film to properly adherev tothe lower lm it is necessary that the casting wheel side of the gelatin'sealing film 34 be placed in juxtaposition with the casting wheel side of the lower strip 44. The outer face of the strip forms a toughened and hardened surfacefappa'rently from the evaporation of the moisture thereirnso that it is not nearly as adhesive as the protected side of the strip. The outer tough side seals only withdiiiiculty, and such a seal is more fragile and shows a greater tendency to split.

The turnover mechanism as illustrated, consists vof two suitably journaled rollers 39 and 40 on a shaft parallelto the die roll axis and two suitably j-ournaled rollers 4I and 42 on an axis perpendicular to the previously mentioned axis and thereabove, so that a l-belt 50 traveling over these pulleys in the order 40, 42, 39, 4l and back to 40 will pick up the film as shown in Figure 3, lift the same through 90 to a vertical direction, rotate through 90, reverse the film into another twist of 90 so that the illm is fed out of this turnover mechanism withthe casting roll side reversed, and shifted laterally so .that this film is now in the same frontal plane as is the lower iilm. The guide rolls 35 and 36 may be driven by a suitable drive system 43 as is shown more clearly in Figure 2. Some of the rolls vmay be driven by traveling belts, as for example the carrier belt 31, or the turnover carrier belt 50. Cerf tain of the rollers may indeed be allowed to'be idlers if they are journaled on comparatively friction free .bearings so that the gelatin nlm itself will cause such guide rolls to rotate.` y

The lower strip of the gelatin 44 is, after being stripped from the casting wheel by the stripper paddle 33, fed over guide rolls 46 and 4l. Guide roll 46 may be oiled by means of a brush y45, rotating in a shallow bath of oil. Alternately this guide roll may -be made of foraminous material, as for example sintered brass, through which oil is fed from` a suitable feed mechanism. It is def sirable that a thin film of oil be maintainedon the surface of this roll so that the outside surface of the gelatin film is oiled so that it will vnot aclhere as readily to later portions of the mechanism. The guide roll 45 is preferably drivenby a sprocket drive 48, shown in Figure 2, so that the surface speed of the pulley is substantially the same as the surface speed of the casting drum. The roll 4l is driven from roll ,4t by a,

crossed belt roll drive system 32. The lower strip gg gelatin 44, thence passes to the cavity die roll The cavity die roll is a most important feature' of the instant machine. The cavity dierroll is designed with al plurality of cavities inits peripheral surface, each cavity forming a single gelatin capsule with each rotation of the cavity wheel. The individual capsule charge is placed in this cavity and it is important that the machine work done in forming the cavity diewheel be ofr a high order so that the cavities will be of precisely identical dimensions. Th consistency of successive charges and the consistency of y,the size of the filled capsules depends, to a large'ex= tent,rupon the` accuracy vci. this cavity die wheel. The exact number of cavities in the face of the die wheel is not of critical importance except to the extent that it determines the number of capsules lled in each'revolution. As shown in the sketch in Figure 3, there are three rows of cavities in staggered relationship around the periphery of the wheel. A single row or any number of rows may be used as desired. There may be any desired number of cavities per row around the circumference ofthe cavity die roll. For illustrative purposes there are 48 cavities shown in each row in the accompanying drawings. As shown more clearly in Figure '7, each cavity 5l, which serves as a lling chamber is cylindrical in nature and has a raised rim 52. The raised ri'm preferably has a width of approximately one to two times the thickness of the gelatin strip. For small size capsules a width of 0.030 inch has proved satisfactory. The height of this raised rim "52, 4alcove the surface of the cavity roll should be at least twice and preferably about three times the thickness of the individual gelatin film. The cavity roll surface 53 is in general the surface of a cylinder but its accuracy is not particularly critical. The surfaces of the raised rim are necessarily very accurate as this raised rim must contact the sealing roll at all portions, during rotation, to give a good cut-out of the capsule.

The cavities may' be elliptical, hexagonal, square, or such other shape as may be desired. The cavity may taper towards the bottom, although no particular advantage is found therein. Such modifications are within the scope of the invention, but are not frequently useful, as the complexity of the machining operations involve usually outweighs the advantages.

Each cavity has inserted therein an ejector plug V54. For cylindrical cavities this plug is cylindrical in configura-tion with a rim 55 thereon.

1 These plugs-fit loosely into a plug retainer 55.

The plugretainer should fit rather snugly into the cavity so that it will retain its position there-in during operations. It may, of course, be held by pins, set' screws, or other suitable means ifV desired, but with good machine shop facilities availableit is usually cheaper to merely malte this pluga press t. Either the rim of the plug or the bottom of the `cavity should be slightly rough or serrated as shown at 51, so that the plug can not seal tight against the bottom of the'cavity. The bottom of the cavity has an air duct 58 leading from its bottoni through. the cavity die rolls to pressure and suction' chests, as later described.

AIn operation'the plug should be of such height that when in its lower position it is substantially even with the upper surface of the plug retainer, so that the filling cavity is a flat bottomed cylinder. Thedepth of this cylinder determines the depth of the fill for each individual capsule and should be consistent for all the cavities in the cavity die fron. This is A'test obtained by using precise` machineoperations throughout the construction of the cavity, the ejector plug and ejector plug retainer. There must be sufficient clearance around the edges of the plug so that air from the air duct 58 can raise the ejector plug until itsy rim contacts the retainer and isr thus held in a raised positionv by air pressure andso that air mayr be evacuated from the cavity during the evacuation portion of the filling cycle. It is desirable but' notnecessary'that the plug come to approximatelyy thetop ofr thecavity when raised by air Vpressure as it `vaids in the ejecting of the-capsule. kThe cavityv rim may be built up or the rim and the plug retainer made integral and screwed into .the surface of the die roll, or such other construction used as may be more convenient under particular manufacturing conditions, with equipment available.

The individual cavities should be fairly accurately spaced around the periphery of the cavity die roll for convenience, as shown in Figure 3. The cavity rolls should be accurately and firmly journaled, as for example by roller bearings upon a very solid shaft, or the shaft should be solidly journaled upon appropriate bearings, because pressures induced by air pressure and vacuum applied during the filling operations may otherwise cause deflection, undue friction, and chattering of this roll.

By suitable manifolding means', as for example illustrated by Figure 6a, the inside of the cavity die roll 49 has a die roll stator |03 containing a suction chest 50 in contact with the interior surface of the cavity die roll so that air is evacuated through air duct 58, during suitable portions of the filling cycle. Air pressure acts through duct 58 during other portions.

This is most easily arranged by a stator |03 in which is arranged the suction chest 59 which has as an integral part thereof manifolding means such that suction is applied over the desired portion of the lling cycle, i. e. from the point il to |3|3 as shown in Figure 9. The suction may be applied through a suction connection |02. Air pressure is applied through the air pressure lead |05, which supplies pressure so that the ejector plugs 54 are raised at approximately the point lll-44, shown in Figure 9. The use of multiple air blasts, by manifolding as shown, is particularly effective in clearing the cavities. A spring loaded sealing member |06 may be used to separate the vacuum from the pressure chests, which member lnay oat in the stator so that any wear or unavoidable irregularities in the internal surface on the die roll will be compensated.

Whereas it is possible to use a stationary shaft upon which the stator is locked, for convenience of drive though the die roll is solidly attached to the axle 15, which is gear driven, and the stator is kept from rotating by a stator positioning pin |20.

For temperature control of the die roll it is particularly convenient to install heating members in this stator, which may well be of brass. Leads to this heating element are shown diagramatically at |02. For temperature control it is desirable that the temperature of this stator be controlled, as by a thermostat. Leads to a thermostat are shown at |01. Any suitable type of thermostat may be used, including either one which is integral and individually adjustable or one may be used in which thermocouple leads are taken to an outside` control. Many variations of temperature control will be obvious to those skilled in the art, and the exact type of thermal control is not an essential feature of the instant invention.

As shown in Figures 3I and 1, there are positioning pins 60 on the front surface of the cavity die roll which pins are accurately positioned with respect to the cavities and are used for the positioning of the filling head. In the particular conguration shown there are sixteen pins for fortyeight holes so that three sets of cavities, that is three cavities in each of the three rows, are filled with each stroke of the filling head. The lling head block 03 is arranged to function in timed relationship with the cavities so that during operation it. performs ay cyclic shift whereby it is lifted:V from the surface of the cavity roll, shifted backwards: and allowed to drop to position, being accurately positioned by the pins 60 and remaining in contact with the cavity roll mechanism during a suitable' portion. of the rotation of the cavity wheel, after which it is raised to repeat the cycle.

The individual filling heads are shown in Figure '1. Each of them consists of a cylinder` 6| in which fits a fillerv assembly 62. The filler assembly is positionable axially so that its lower edge projects below the surface of the ller head block. 63 by an adjustable amount, usually equal to fromv 1 to2 times the thickness ofl the film. The filler: assembly 62 may be integral or built up and consists of a. cylindrical shell through which passes a filler passage 64. This filler passage extends from the supply means, as described later, in a hopper through the ller assembly. Around the lower end of the filler assembly is an annular space lled with a foraminous material t5. The foraminous material may consists of felt, sintered glass or sintered metals. For filling routine vitamin products sintered metal is usually particularly convenient because it may be turned to size and even soldered or brazed in location so that the sizing .is accurate, and it may be readily sterilized. From the upper surface of this foraminous material there is an exhaust duct 06. The exhaust duct leads into an exhaust annulus 6l out into the periphery of the ller assembly which is in turn positioned opposite the exhaust manifold 68, iviich in turn is connected to the exhaust tubing During the ll operations the filler head block 63 cornes down into juxtaposition with the gelatin film riding on the cavity die roll 4S. The exterior diameter of the filler assembly should be such that there is sufficient clearance between it and the cylindrical surface of the cavity for the thickest gelatin lm which is to be used with the machine.

A plurality of these filler assemblies are positioned so that the 3 by 3 block of cavities has a ller head in each. The ller heads are mounted in a filler head block 3.

As shown diagrammatically in Figure '7, this filler head block may be equipped with a filler block heater element |08, and a filler block thermostat |09. As mentioned elsewhere, any of the conventional types of heaters and thermostats may be used. Electrical control is particularly convenient. Heating of the block is not always necessary but it is particularly convenient, when the machine is used for hygroscopic powders, as it keeps the block warm so that moisture will not cause the. powder passages or the foraminous material to become clogged.

The filler head :block has mounted thereon a powder hopper 69. The powder hopper is'preferably made of transparent material so that its contents may be readily observed. As shown in Figure 1, the powder hopper has a stirrer l0 mounted therein which consists of wires mounted on a shaft which is mounted in the top of the powder hopper and is turned by a flexible shaft l I driven by a suitable source of power. The ller passages extend up to this powder hopper. It is desirable that the stirrer be rotated suiiciently rapidly to avoid caking or bridging of the powder. If desired the powder hopper 69 may be provided with a feed opening 12 in which a flexible duct carrying additional powder may be inserted so that the hopper may be filled automatically or .aeaias 1: manually as maybe desired with additional pow- The filler head block assembly is positioned in relationship to the cavity die roll by means of the eccentric assembly system shown in Figure 5.

The block 63 isA mounted on a lifting arm 13,

which lifting arm has a slot 14 therein through which is assembled the cavity die roll axle l5. At the lower end of the lifting arm there is an eccentric 16 mounted below the mid position of the cavity block ona suitable eccentric shaft ll.

.. The eccentric itself revolves in the eccentric guide opening 18. This opening is so proportioned that Awith the eccentric shaft rotating in the same direction as the cavity die roll, clockwise as illustrated, the eccentric 16 contacts the lower end of the lifting arm in approximately the position as yshown in-Figure 6. At this point the eccentric lifts the arm substantially radially relative to the cavity die block until the positioning block 19 clears the positioning pin 60. As soon as this pin is cleared the friction and direction of motion of Y. the eccentricpullsthearm and the accompanyingfi-ller head block assembly in a counterclockwise vdirection in an elevated position to approximately the position shown at the dotted line in A'Figure 5. `At this point the eccentric pin having passed itsl top center and having started downward lowers the arm and the filler head block assembly until therpins'pick up the positioning block 19 and cause the entire assembly to rotate clockwise again. As the block is rotated clockwiseA the eccentric continues to drop until the ...entire weight of the -ller head block rests upon thepositioning pins and/or the gelatin film and cavity dieroll, at whichgpoint thefeccentric turns free in the eccentric guide opening until time for the cycle to begin again.

K An identical mechanism is present on the back -side of the cavityA diedroll so that the powder 4hopper is supported both in front and in back Vby an identical l,symmetrical mechanism. .usually most convenient that thisrmechanism be It4 is behind' the drive for the cavity die roll. For normaloperations it is Vdesirable that the weight of the,` cavity block rest on the gelatin film rather than on the positioningv pins, so thatpthe gelatin lmacts as Va seal and rprevents the leakage of air around the periphery of the filler. It is desirable but not necessary that the positioning pins and positioning-block bear a relationship such that ifthe gelatin lm is removed by inadvertence, or at the beginning or end of operation, the weight of the Vfiller block is taken by the pins rather than by the raised rims of the cavities. if the biockis allowed to pound on the cavities with no gelatin inbetween, the rims may become battered. f v

" By this mechanism and ymethod the filler head block assembly is raised during the non-filling portion ,of the cycle and positioned again over a new set of cavitiesfOf course, the filler head .group vof cavitiesA as desired. Usually for the sizecapSuleS which'are desired it is more convenient -if' morethan one capsule Lbe filled per row per cycle.k Asiiiusirated, three arefiiied.'

. r1.1@ gelede steriele@ weer 'bereide' w11 .4

- and into contact with the cavity die roll 49. As

positioned on the raised rim and Figure 11 shows the film having been pulled down into contact with the ejector plug and plug retainer. The suction is maintained on the chamber until after the capsule is sealed and cut-out. Usually a higher degree of vacuum is maintained under the gelatin lm than is used above it in the filling operations.

As the gelatin lined chamber advances the filler head block is lowered into contact therewith, as described above, and shown schematically in Figure 11, taken on line I I-i I. The filler assembly may enter partially into the gelatin lined container. The lling head itself preferably rests on the gelatin film.

At this portion of the cycle, at about the point Il-ll of Figure 9, the lling occurs. The lled powder should be of such consistency in relation to the size of openings that it will not flow through the ller passage 64 under the influence of gravityy and such vibrations as occur, but instead, after the machine is in operation, blocks or bridges across the passage.

When the ller assembly is in position, Vacuum is applied through the exhaust manifold 58. To insure adequate and proper filling, it is desirable that the air be evacuated through the' passage 68 in slugs. This is accomplished by connecting the exhaust tubing to a solenoid operated valve which is connected to a vacuum pump (not shown). The solenoid valve may be actuated by a microswitch 8|, which has a contact 'member 82, riding upon actuating. pins83, on a cam plate 84. These contacting pins are so arranged that the solenoid releases the air through the exhaust duct `68 into the Vacuum pump inbursts which gives a pulsating'ilow to the powder and causes it to compact to a uniform density in the filling chamber. The foraminous material 65 prevents,v the powder from flowing through the exhaust ducts and insures a comparatively uniform and consistentdensity of the powder. Under normal operating conditions, if subjected to a series of burstsof vacuum, five being a suitable number although from a single burst to as many as a dozen (for differentl powders) may be used if desired, a powder may be compacted to a remarkably uniform density. It has been found that homogeneous powders will be normally compacted by such an arrangement so that the density of a charge will not ordinarily vary more than a fraction of one per cent. If the charge chambers are of consistent size and the gelatin lm is cast to a consistent thickness, this will mean that the individual chambers will be filled uniformly so that the final capsules contain equal dosages. f

. The size of .thesecharges may be adjusted by varying the amount which the ller assembly 62 projects into the charge chamber, or by varying thedepth of the charge chamber. Some variation may be introduced by varying the pressures and vacuums used.

After the lling operation is completed,L and the vacuum is released, the filling head block 'assembly is liftedby means of the cam and lifta sealing roll spring assembly 89 so that the pressure between it and the cavity die roll may be may be compensatedby spring action.

As shown in Figures 3 and 5, this sealing roll though not necessarily mated to match with the cavities in the die roll, through which vacuum.

is applied as by the manifold l Il andthe vacuum connection H0. The suction through these oril2 filled capsule-to be pressed out of the' chamber and allows it to spring to its natural shape:

To give a good clean seal and tocut the gelatin completely out ofthe web it is desirable that the sealing roll spring assembly 89, press comparatively firmly upon the Surface of the sealing roll. If there are any irregularities in the rim, a small flash may remain which may cause Athe capsule to stick in the web, but under normal operating conditions,l if the-rolls are accurately made, the capsules will be completely detached. As shown in Figure 1 and inFigure 9, the capsules after passing the line 14-14 have a tendency to be ejected by the plug and air pressure. ,This is followed` by the action vof two revolving.

\ brushes 'iagwhich rotate inra counterclockwise ces assists in positioning the sealing film so4 that it will not slide unduly on the surface of the ,sealing roll.

an air pressure assembly,.such as is used in the cavity die roll, may be embodied in the sealing roll to Aassist in releasing thegelatin film and capsules from the sealing; roll. As shown at I I2,

an oil fed wick may rest upon the sur-face of the sealing roll, being in turn supplied by a suitable oil supply so that-a thin film ofY oil is maintained on the surface ofr the seal-ing roll at all times to prevent, adherence of the gelatin to this roll. It will be found that if the roll is over-heated the gelatiny is. particularlyv apt to stick, and that if a gelatin mix requires a higher temperature, particular care is necessary to insure that this roll have a high gloss. and be adequately oiled to prevent. sticking or building up of gelatin on the surface.

. Asy more particularly show-n in Figure 5, a heater member 86 isin contactwith the side ofA this sealing roll stator H3, and is thermostatically controlledby means of a thermostat 8] so that the temperature4 ofA this roll may be maintained as desired; Whereas the thermostat Bind the' heater are shown in a stator, they may be built, as sliding upon the sidesurface of this sealing roll or the heater andthe thermostat may be, built intgeraljV with thisy sealing roll andL conmay be by sliding contacts brought out thlfiugh the axlel desired.; The stator is retained` in position by thesealing roll stator positioning pin lili!V andits associated bracket 113i?. rIjhe temperature adjustment of this roll may he critical will be lateiju described.- Y

As `the cavity die rolll andthe sealing roll rotate'. together, the rspring action; abovel described, first causes the, sealing film. 3'4 to contact the lower stripi 4,4 and then to press upon; this lower strip which in., turn is supportedby the raised rlrii. &'2,i1 nt.ilV the raSed rim cuts into the; combined gelati-n films. as.. shown at Figure 13. The compression-1actioncaused thisjpressure causes the. gelatincaughti between the. raised rimA and sealing rollV to. be extruded andas it isKV pressed between these; merrrbers.` it unites with. itself. so that a sealed` joint is formed.` The two4 gelatin lm's under proper operating Qond-itionspare. so uniformly united that it requires inspection. t0 loca-te the seal andl the. seal is nearly asfgtrong' as the walll of the capsule.- The residual web. 88, is. forcedy d own on theoutside of the raised rims 52 and into, the spaceY providedv therein. As the two rolls separate as they turn,v air pressure may be appliedA by means, of, a, manifoldjunderthe cavi-.ty die: so,- as.- to lraise theejectof. plug, 54 as netions.-

This action of raising the ejector plug causes the If the particular gelatin com. pound used appears to stick to the sealing roll,

shown in ligure la, taken..along,the.li11e.L4f-l4..

.direction at a comparatively high rate of speed,

their peripheral speed being several timesl the surface speed of the cavity die roll. These brushes have an additional tendency to throw the capsules upon a'conveyor belt 9 1 which removes the capsules to a discharge point. The web with the capsules 'cut out thereof is pulled around the web roller 32 and through the web removal rollers 93, which rollers arey rotated at a slightly higher surface speed so as to pull the web and stretch it so that it is easily removed. The web from this point is fed to a waste container or otherwise disposed'of. Othermeansmay be used to remove the residual web, as frequently just gravity is adequate. Individual suction cups; brushes', and other methods show-n in the priorart may be used.

The sealing roll 'spring assembly 89 maybe 'any conventional universal assemblyV 'whereby the spring loaded sealing lroller is permitted to run in contact. w-ith the gelatin contacting; the cavity' die rol-l. AS shown, the'axles of these two rollers are maintained essentially parallelby the slots in the retaining' trame 94. However, in and out motion' in the direction of the line of centers is permitted and occurs against'. the sprng,.com pression of which is adjustable by means of the tightening handle 95. Y

Figure 2 shows in diagrammatic form the dri-v ing belt system for the machine; For normal operation, as herein described,r it isdesirable that the gelatin strip remain slackA but not loose at all points.v Tension shouldy be avoided in the gelatin strip. This is most easily.' accomplished by insurfing that thesurface speed of each of the gelatin'contaeting rollers is the sameas the surface speed of the-castingwheel. Normally the gelatin hlm will have a tendency to shrinkV from Adrying after it is removed from'the casting wheel, but atv the same time will* have a tendency to stretch because of the warming of the gelatin andf'because of the natural weight of the gelatin tending to stretch it' asili-passes over-the rollers. In generaL it will be found preferable to drivethe rollers'by positive inea-ns by either sprockets and chains orv by direct gearing; This automatically' tends to stabilize-the-'length of; the east film; The number of teeth in each of the gears isnot critical nor is the size of the rollers; but they should beso related thatA the surfacev speed of all? rollers: be substantially-uniform throughout; with the exception ofirollers 93, the web removing rollers, which may be driven at a higher speed to remove the film.

Because of thepeculiar properties of gelatin, it hasv a tendency to be slowly elastic; vIf stretched, a rhlm of gelatin has a tendency to recover its original shape slowly. Accordingly; if the gelatin strip is stretched' at any point` during its passageV through the machine it; will tend" to recover to its original dimensions; Vthough slowly.

, 13 If desired', advantage Vmaybe takenofthis char-j acteristic by stretching theA lm by, driving the casting roller slower-than the'other'roller's in the machine. If this isfdone, after the capsuleshave been cut and emerged from the die roll as essentially"spherical,` the gelatin films forming the capsule will shrink in the direction in which they Wereoriginally stretched in such a fashion as to give a football shaped capsule. This YcastingA of ellipticalcapsules from roundcavitiesy is angimportant feature of this invention, but is not necessarily an essential feature; as if it be desired to cast` spherical capsules, bythe Same token, this same stretchvmustbeavoided.r o f `-As shown'in Figures land 2, a rdrive motor 96, through a worm gearsystem 91 vdrives the main shaft' 98 which inturn drives the casting-wheel bymeans ofv the casting Wheel gear system-09. In the particular lmodification shown, .beveled gears |00 drive a jack-#shaft 0| on which are mounted sprockets for driving various parts of the-machine. Each of thevrotating drive wheels is preferably driven in some fashion from a `povvcred shaft with the exception of 'spring loaded roll 85,(which may. be driven merelyV by contact because ofthe high pressure betweenjit and the cavity die roll.

vIfmated vacuum .openings ||4 are used, the roll 85 should be geared or otherwisel positively driven inV timed relationship with the cavity die roll as shovvn, f o l Only one drive pulley'lis necessary for each of the belted roller systems.v Y Figure 2 shows diagrammatically certain `aspects of a particular system'of roller drives which has proved satisfactory. l It is readily Within the range II,of anyone skilled in theartvto workout othermethods of drives which are satisfactory for `driving the variousmembers at the speeds shown' to be desirable elsewherefinthis specilication..V As shown inrli'igure 2 fromthe jackshafty there is a main chain roller drive ||5 which drives the cluster shaft |6. 4From this cluster shaft by means of a paddle drive belt ||1 the paddle 33 is driven.;` By means of the sprocket drive 48 and an associated beltdrive the guide rollers 46 and 4'!` are driven from the same shaft. The turnover mechanism` is driven by means of a turnover mechanism chain drive |.|8. The carrier belt 3'|-,isk driven by an appropriate carrier belt drive ||9. From the .cluster shaft I Iii by means of a suitable idler gear is driven the eccentric shaft 11 and related mechanism, by an eccentric shaft gear 2|. In turn therefrom, throughidlergear |22 .is driven. the cavity die roll gear |'23Vand vin turn therefrom the sealing roll gear |24.` f v From the Vjack-shaft |0| by means of the web removal roller sprocket drivev |25 there is driven `the web removal rollers and by an'V associated belt rand pulley system functioning as a discharge conveyor beltdrive |26, the discharge beltand associated mechanism is driven. From this in turn is driven the revolving'brush drive system i The entire drivesystem is Within the skill of rthe art and may be readily modified in any number of various Ways Without departing from the .scope of the invention. It isto be notedfthat, the system as shown, by changing onesprocket in the main chainroller drive |5 and coordinating theV sprocket drive chain lengthv therewith, it is possible tri-change the speed relationship beo tvveen the cavity-die roll and all gelatin strip contacjginglmsmbers arcuate@ therewith and .the cast- Y exact temperatures and humidity at practically every point of operationsA may be varied. over a rather Wide temperature and yhumidity and still give satisfactory'resultsthe 4relative relationships for a. particular operation are comparatively critical,v and Yfor any given run should remain reasonably constant. For example the proportion of waterin the gelatin film maybe decreased .as the temperature is raised. A higher temperature may'be used for 'the casting roll and throughout if less glycerine is used. A longer drying time is required at lower temperatures or if the relative humidity ishigher. The relative temperature between the cavity die roll and the sealingV roll is extremely important in adjusting the position of the sealing line. For example Warmer gelatin ows more readily .than cold. .Thetemperature of thev cavity die roll is controlled by thermostatic means from a thermostat, diagrammatically illustrated as |02, which controls the heat supply to the stator |03. The heater element may lie in or on the non-rotating members of the cavity dieroll assembly and may be an electrical resistance element or other source o f thermal energy as shown at |01. The amount of energy being supplied must be under rather vadequate and rapid control to insure proper temperature relations. As setforth in certain of the specific examplesif this cavity die roll is kept at a slightly lower temperature than the sealing roll the gelatin strips in contact with each vvillV be at those respective temperatures. When sealed vtogether the portions contacting the walls and bottom ofthe cavity-Will be cooler than the portion constituting the top. When released, the

ho't portion will stretch'more easily. 'Ihe cool' portions will tend to shrink. As the capsule assumes its normal Yrounded shape, the cool portion of gelatin, by attempting to shrink to its original dimensions, will stretch the portion constituting the top and because this portion is Warmer itWill stretch more readily, and if the relative temperatures are properly adjusted, the line of seal Will be equatorially located on thecapsule It is not necessary that this'sealing be equatorial and by temperature adjustment the line of seal may be adjusted as desired. vThe equatorial seal is-suggested as the type of seal'which in the past has most readily met with consumer acceptance.

The `guide rollers, oil rolls, turnover rolls, etc., are normally permittedto remain at room temperature or at such temperature as they assume from their contactwith'the gelatin lm and no temperature control is necessary. However, for certain operative conditions, as for example where it is'desired to use alower Water contentin the film so as to give a more rapid drying in the nal capsule, it may be'desired that these rollers in turn be temperature controlled. The casting Wheel roller is normally permitted to assume its natural temperature. As the average gelatin fluid oWs upon it this film will be somewhat cooled and will solidify rather rapidly buty then as the moisture begins to evaporate from the surface ofthe film `it; wi1l tendto coolthe .wheel below room, temperature and by the time the gelatin film leaves the casting wheel it may be below room temperature. If extremely stable ior f-a'st setting gelatin film is used it may `be desirable to warm the casting wheel so as to cause more rapid evaporation ci` the moisture *and thus permit faster operation `of the machine. Additional speed may be obtained from some gelatins by using warmed air to set the nlm.

It may accordingly be seen that the various elements of the machine are each yindivichially variable over a compzu'ativelyv large range but such variations arenecessarily and inherently inter-related so that for satisfactory operation most of the variables, including temperatures, concentrations, humidity and pressures, etc., must remain within rather narrow limits for satisfactory results, .unless a compensating change is introdueed at another portion of the cycle.

Accordingly, certain specic examples are herewith given, describing certain satisfactory operating conditions. 'It is not to he :assumed or implied that these operating conditions are the only satisfactory conditions within the `range of our invention, as by variation in one element, a variation in anotherelement'may be compensated so that, for example, the' temperature may be operated vcomparatively highl by using comparatively little water in the mix. Similarly, larger amounts of water maybe used `at comparatively lower temperatures. rThe rconditions herewith given are certain satisfactory lconditions for operation vas indicated.

Example 1 A gelatin mix was `prepared by combining 48 parts of .commercial gelatin', .'18 parts of U. S. P. glycerine and 36 `parts of water. The .mixture was held `at approximately 40"Y F'. lovernight to allow the gelatin to swell and'it was then slowly warmed up with the laid of a steam coil to rapproximately Y1,36" F. As a matter of choice butnot at all necessary, suiiicient yellow' dye, water soluble and meeting F. D. A. approval, wasadded to color the :gelatinand suiiicient 'titanium` dioxide,` so that thinlayers would not be transparent. The -gelatin was made up approximately twenty-four hours before use. In .processing the gelatin was maintained at 136 F. as it was iiowed through the ygelatin hopper 2l on to the casting wheel 2G. The position of Ythe doctor blade was so adjusted that after drying sufficiently to -form in capsules, the gelatin had a iilmvthickness `of 002e, plus or :minus 0.005". The temperature of the wheel was allowed to vadjust itself to v-room temperature which was held between *73 .and '75 F. Relative humidity was heldat Vapproximately 50%. The temperature of the die roll was held at room tempera-ture between '73 and .'75 The pressure'of the compression roll was sufficient to completely jslice through the gelatin. A dry powdered .multiple vitamin preparation was .used in the filling. vAt `a temperature .of 88" -to 92 F.

on the `compression roll a uniform, nrm, solid shell was formed with `the Vportions .of the ,gelatin capsule approximately equal, no feathering, a satisfactory cut-out, :good edge, and a Vgenerally satisfactory capsule. As a matterfof test the temperature ci the compression rollxwas varied. At '75 F. the capsules were not sealed. At180 to,83f F. the capsules were .partially sealed but it was not a strong sealandhad gelatin feathersremaining. on Vthe rcapsuleVand the upper part of the shell was smaller. At95 to 100 F. a strong seal was :obtained withxno feather-'ing and :theupper i6 part of the gelatin shell was larger. At 105 to 110 F. the gelatin strip melted'on the compression roll .and the Ytest was ended.

' Example 2 Usingthe same gelatin mix the compression roll was maintained at a constant temperature of 90 F. and the temperature of thecavity `die roll was varied. At a temperature ,of from 58 to 65 F. thev seal was not strong, had feathers and the lower part of the shell was considerably smaller. A temperature of '70 to '75 F. showed a strong, even seal with a good iirm shell. At -a temperature of 80 to 85F. a strong seal was .found but the lower part of the shell was larger. The capsule was easily deformed in shape giving a rather delicate capsule, until it vhad time to cool. The capsules had va tendency to stretch in the die roll. l'

. y Example 3 The effect of theV room temperature on vthe making ofthe capsules was, tested by adjusting the temperature 01E the casting roll to 90 F., of the cavity die roll '95 F., the gelatin as above being used. At a room temperature of 58 F. a strong gelatin strip was formed on the casting roll which was hard to work with and hard to handle. At 60 to 65 F. the resh'capsule which was strong and held its shape was formed. At to '75 F. the capsule `was not quite as strong and held its shape well and dried lslightly faster than above. At to 85 F. the capsule broke easily and the film was too hot for satisfactory operations with this mix.

Example 4 A gelatin mixture was prepared as above using proportions of 40% gelatin, 30% glycerine and 30% water. A satisfactory capsule was readily `manuiactured'from this mixture but it was `found that certainpowders such yas ascorbic acid and iron vsalts'had a tendency to react with the shell and produced discoloration.

Example 5 A gelatin mix of A128% gelatin, 18% glycerine and 30% .water was used. This gelatin strip formed ygood stable capsules, readily inoapsulated materials and was generally satisfactory although `it had a slight tendency to leak oils. It was satisfactory, giving particularly good results with such materials as ascorbic acid and iron salts.

Example 6 A gelatin `nlm was iormed from liquid gelatin l1n `accordance with the .process described vin the patent, No. 2,349,511, to Louis P. Miller. The `gelatin lmfas lso formed was used torencapsulate 'a powder vitamin preparation with the'ternperatures of the `dieroll of 70 to 75 F. and a compression ,ro1l, temperature of 88 to 92 F. Sat isfactory pharmaceutical capsules were obtained.

Example 7 17y elliptical in shape,- beingv shaped somewhat. like av football. This shapehasparticular advantages for large capsules because it isA more rreadily swallowed.

Example The sprocket drive mechanism was adjusted so that thesurface speed of the cavity die roll was approximately 15%' greater than that of the casting Wheel; The gelatin mix was as set forth in Example 1', the temperatures were as set forth in Example 1 for the satisfactory centrally locatedseal and the capsules filled with a multiple vitamin preparation. As formed by the machine, the capsules were markedly longer than their minimum diameter, possessing an even, oval form and beingy sturdy and well shaped.

Varying degrees of eccentricity of the capsules can be'obtained by varying the speed ratios of the casting surface and die means, and the gelatin formulas. The shape obtained, similar to that of a football, approximates that of a prolate spheroid.

YThe foregoing examples disclose certain modifications of the gelatin lms which may be used satisfactorily in the method and on the machine as herein described. Other gelatin mixes may be used,A in each instance av fewminutes experimentation will permit the skilledv observer to judge the exact temperatures which are desirable fora particular gelatin mix. In general, if the die rolls are too hot the gelatin becomes too sticky and if they are too cool, a weak seal is formed; if disproportionate, an oi center seal is formed. Within these generalized limitations a wide variety of capsules may be formed, with a wide variety of gelatin formulations and powder contents.

Within limits a convenient method ofv varying the nll of the machine is by varying the thickness of the gelatin film. By means of adjust'- ment of the doctor blade inrelation to the casting wheel'a considerable variation will take place in Wall thickness, and whereas the, outside of4 the capsule will remain substantially of the same size the duality of the iill is varied because of the change in size of the cavity'. This variation is particularly convenient when powders are used with varying bulk density and with varying therapeutic activities, and uniform potency capsules are desired.

When desirable andv operating under controlledv conditions, this machine may be used with the lethods herein described over prolonged periods without stopping the machine or in any way interrupting itsV operation. The cost oiv the operation of this machine will be found to be markedly less and the convenience markedly more than any of the machines heretofore placed upon the market.

Various other mechanical equivalents may be used, as for'exarnple, a casting belt may be used instead of a wheel. Separate drums or casting means may be used for the ormation of the strips. Gther heating means, such as radiant heat, induction heat, or hot water, etc., may be used for heat control of the various elements as indicated, each with appropriate means of` control for such heating means.

Obviously, the invention is not limited to the specific details of the apparatus as illustratedI as these may be. modified in the skill of those familiar with such machines. Furthermore, the various features o'i the invention. may be used conjointly or separatelyA for the specic advantages or improvements ofV each; without neces;-

Uli

sarily incorporating all of the various features and advantages. Different combinations and sub-combinations are within the scope of our invention as set forth by the appended claims. As our invention, an improvement to the art of making capsules, w-e claim:

1. 'I'he methodV of forming gelatin capsules from soft gelatin strips which comprises the steps of casting a liquid gelatin as a iilm on a casting surface, drying the gelatin film so that it will possess plastic characteristics, splitting said gelatin iilm into at least two strips, subjecting each strip to a diierent thermal treatment, forming pockets in one strip only', covering said formed pockets. withthe other strip sol that the casting surface contacted side isv placed in juxtaposition. tothe casting surface contacting side of the pocket containing strip, sealing said strips together by pressure and simultaneously: cutting out said formed pocket and the coveringl portions of said' other strip, whereby a capsule is formed and whereby the capsule shapes itselfl into. the desired form as a result of the release of natural strains set up in the gelatin.

2. The method of. forming symmetric capsules. in asymmetric dies which comprises subjecting vtwo gelatin iilms to different heat treatments,

forming an empty capsule shell by the localized application of subatxnospheric pressure to one side only of one strip only, iilling said shell, placing in juxtaposition thereto the other of said lms, sealing parts ofv each to the other by the localized application of pressure which combines the sealing of the iilms with the cutting out. of the desired portion from the web, and permit.- ting the strains induced in the formation to. act upon the gelatin films whereby the deformation as a result of the differential heat treatment results in a capsule of a desired shape.

3. The method of forming a symmetric gelatin capsule which comprises forming a cup shaped cavity in a gelatin strip, filling said cavity, juxtapositioning an essentially plane sealing strip of gelatin on the top of said cavity, said seal strip being at a higher temperature than .that of the strip'forming the cup, sealing the edges of the strips adjacent to the cavity to each other by the yaction of pressure simultaneously cutting out said capsule from the web, and releasing said capsule whereby the different heat treatments of the portions of gelatin strips forming the capsulecauses a symmetric capsule to be formed by diierential shrinking and stretching of the respective portions of the gelatin.

il. An apparatus for forming and iilling cap-` sules with a powder which comprises means for castingl a pair of gelatin capsule forming bands at the saine rate, forming die means contacting one side only of one band whereby cavities are formed therein, means for feeding powders into said formed cavities, means for heating the second of said bands, `means for placing the second of Asaid bands without distortion in juxtaposition tothe cavity containing band and means for peripheral sealing said bands to each other around each cavity and simultaneously cutting out the lled portion thereby forming capsules from said bands.

5f. The method ofA formingsealed capsules from strip material having the characteristic of 4plastic iiow, which comprises forming a shaped capsule from two strips of such strip material which strips are in a different thermalv condition at the time-ofV forming andl sealing-,whereby said formed. capsules shape themselves into the desired final- I9 shape in the process of relief of the stress resulting from said different thermal conditions.

6. The method of forming capsules from strip material having the characteristic of plastic flow, which comprises forming a shaped capsule from two strips of such strip material which strips are in a different thermal and mechanical condition at the time of formation and sealing, whereby said capsules change from the form in which they are produced into a desired configuration by the relier" of internal stresses resulting from said different thermal and mechanical conditions.

'7. A method of forming soft gelatin capsules which comprises casting a liquid soit gelatin mix into a nlm on a casting surface, solidifying said film by the removal of part of the moisture present therein, separating said film into two strips, reversing one of said strips, forming a cavity in one of said strips, lling said cavity, placing the other of said strips into juxtaposition to the first of said strips in such manner that the side of each of the films which were adjacent the said casting surface are placed adjacent to each other, applying pressure to the peripheries of said lled portions, thereby sealing together and cutting out portions of said films to form capsules.

8. The method of forming powder-filled soit gelatin capsules which comprises forming a series of pockets in an unstretched gelatin nlm, lling said pockets with powder, warming a second gelatin film to a higher temperature than said rst llm, placing a substantially nat portion of said second nlm of the same length as said first film in juxtaposition to the gelatin nlm, sealing each pocket in said gelatin film to the matching portion of said second film, and simultaneously cutting out such portions around the entire periphery of said pockets, thereby forming capsules, separating the capsules from the residual portion of the films and permitting the thus formed capsules by the release of natural inherent strains to form themselves into the desired conguration.

9. The method of capsulating a desired quantity or powder comprising the steps or sequentially applying a sub-atmospheric pressure to localized portions of a single nlm, and drawing said lm inwardly thereby forming a series of empty capsule shells, placing adjacent to each shell a ilowable source of powder, reducing the pressure within said shell whereby powder is caused to now into said shell, restraining the flow of said powder outwardly from said shell, maintaining the flow of powder until a predetermined quantity has nowed into said shell, warming a second nlm to a higher temperature than said first lm, placing an undistorted portion or said second nlm equal in length to the rst hlm in juxtaposition to the first film, applying pressure around the entire periphery of each shell thereby sealing the two gelatin films together, releasing the thus formed capsules from confinement and permitting the thus cut-out portion of the gelatin films by the release of natural inherent strains to adiust the thus formed capsule to a desired final form.

l0. The method of forming elliptical gelatin capsules in rounddies which comprises equally stretching two films from which the capsules are formed prior to formation of the capsulesheat ing the rst of said iilms to a higher temperature than the second of said films, forming round cavities in the second of said iilms of sufficient size to accommodate the material to be encapsulated, filling said cavities with the material to be encapsulated, covering the lled cavities with the first film, and simultaneously sealing together and cutting out round portions from each nlm thereby forming a capsule, releasing said capsule from connement whereby the strains induced by the equal stretching and the unequal heating form a minor diameter and a symmetrical elliptical capsule.

11. An apparatus for forming and lling gelatin capsules with powder, comprising means for forming a pair of gelatin strips at the same rate, means for heating the second of said strips to a higher temperature than the nrst of said strips, a capsule cavity die roll contacting one side only of the first of said strips, means for reducing the pressure in the cavities in said die roll to form capsule shells of a sufficient size to accommodate the powder to be encapsulated in the nrst of said strips, means for filling a powder into said cavities, means for placing the second of said strips in undistorted relationship in juxtaposition to the first of said strips, and means for simultaneously cutting out and sealing said strips to each other around the periphery of each cavity, thereby forming capsules from said strips.

12. A machine for forming and iilling powdered gelatin capsules comprising ineans for cast ing two gelatin films at an equal rate on a single wheel, a cavity die roll comprising substantially cylindrical cavities and drive means for both the means for casting and the cavity die roll, the drive means for the cavity die roll 1ceing designed to drive the cavity die roll at a substantially higher surface speed than the casting surface speed whereby one gelatin strip, stretched in one direction only, is delivered to the cavity die roll, means for supplying loose powder, a substantially cylindrical seal roll, means for driving the seal roll at the same surface speed as the cavity die roll, means for heating said seal roll, means for feeding the second gelatin strip into contact with the seal roll so that substantially the entire second strip is warmed by contact with the seal roll, and means for pressing said seal roll against said die roll, thereby simultaneously cutting out and sealing the portions of the gelatin strips surrounding the'powder, whereby powder-filled capsules are formed possessing an elliptical seal line.

13. The method of forming gelatin capsules from soft gelatin strips which comprises the step different thermal treatment, forming pockets extending away from the casting surface contacting side in one strip only, filling said pockets with capsule contents, covering said lilled formed pockets with the other strip so that the casting surface contacting side is placed in juxtaposition to the casting surface contacting side oi the illled-pocket-containing strip, sealing together by pressure and simultaneously cutting out said formed filled pockets together with the adjacent portions o the covering strip, whereby a capsule is formed, and releasing said capsule from connement whereby the inherent strains from said thermal treatment cause the thus formed capsule to attain the desired shape.

14. An apparatus for forming and lling powm der-containing capsules comprising a moving casting surface, means for simultaneously casting two parallel strips of material having the characteristics of plastic low in juxtaposition to and approximately parallel to each other on said surface, means for removing each of said strips from the surface, means for elevating, reversing and laterally shifting one of said strips to a position whereby it faces in reversed relationship the vother said strip with the casting surface contactcavities therein; a vacuum forming means for ing sides of the said strips facing each other, a

die roll, means in said die roll for forming cavities of a size sucient to accommodate the pow- -der to be encapsulated in the other of said strips, means for lling a powder into the cavities, and means operating against the said die roll for pressing together, cutting out and sealing together the two strips around the powder-containing portions, thereby forming capsules.

15. In an apparatus for forming and lling capsules, the combination of means for casting two parallel strips of material having the characteristics of plastic ilow on a single castingr surface, means for removing said strips from said casting surface, means for forming in one of said strips a plurality of cavities extending away from the casting surface contacting si-de of said one kof said strips, means for filling each of these cavities with the complete contents of a single capsule, means for elevating, reversing and laterally shifting the second of said strips, and means for placing the second of said strips in casting surface side to casting surface side contact with the first and cutting out and sealing together the portions of the two strips surrounding the filled cavities.

16. In a machine for filling soft gelatin capsules with powdered materials; a ller head block; a plurality of cylindrical openings in said block, in each of said openings, a filler assembly comprising a filler passage, a foraminous material positioned in said Filter assembly, surrounding the lower end of the filler passage, suction means, suction passages from said suction means to the upper portion of said foraminous material; a die roll, a plurality of capsule forming pulling down a gelatin film and maintaining a cup-shaped lining of gelatin in said cavities, said vacuum forming means having a stronger vacuum than said suction means, positioning means for positioning said filler head block adjacent said cavities, with a cavity under each of said ller assemblies, and such a space between said block and said die roll as to be sealable by a capsule forming strip; and a powder supply means for supplying powder to said filler passages.

FRANK E. STIRN. ARTHUR S. TAYLOR.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 263,750 Anthony et al. Sept. 5, 1882 564,340 Reed July 21, 1896 1,149,844 Lieber Aug. 1.0, 1915 1,540,872 Bates June 9, 1925 1,895,899 Schaub Jan. 31, 1933 2,097,290 Parkin Oct. 26, 1937 2,152,101 Scherer Mar. 28, 1939 2,210,509 Strauch Aug. 6, 1940 2,227,728 Lombi Jan. 7, 1941 2,249,612 Kalowski July 15, 1941 2,275,654 Ravenscroft et al. Mar. 10, 1942 2,279,505 Ravenscroft Apr. 14, 1942 2,292,760 Kath Aug. 11, 1942 2,296,744 4Simmons Sept, 22, 1942 2,323,581 Weckesser July 6, 1943 2,328,843 Osterhof Sept. 7, 1943 2,342,977 Snyder Feb. 29, 1944 2,379,831 Scherer July 3, 1945 2,420,310 Goodman May 13, 1947 2,431,843 Swoger Dec. 2, 1947 2,436,993 Fisher, Jr. Mar. 2, 1948 2,438,089 Carson Mar. 16, 1948 2,490,781 Cloud Dec. 13, 1949 2,497,212 Donofrio Feb. 14, 1950

Images