US2605036A - Filling machine with constant drawback - Google Patents

Description

July 29, 1952 F. J. cozzol.:

` FILLING MACHINE WITH CONSTANT DRANBACN Filed May 4, 1949 Patented July 29, 1952 FILLING MACHINE WITH 'CONSTAN T DRAWBACK Frank J. Cozzoli, Plainfield, N. J. v Application May 4, 1949, Serial No. 91,306 I 6 Claims.

Y o l The present invention relates to dispensing machines and is Yconcerned particularly with a machine for lling ampuls, tubes, vials and like containers with a pharmaceutical preparation, in a dripless manner. The invention has for its main objectives to render available a relatively Y inexpensive machine embodying a minimum number of parts easy to manufacture, assemble, and to maintain in fclean condition, a machine constructed and arranged Vaccurately to measure and dispense predetermined quantities of liquid preparations into small throated containers, a machine thatq-is constructed to employ as part of the measuring and dispensing mechanism, a standard commercial glass syringe, a machine capable ofvariation Vnot only in the unit dispensed within the range of the particular syringe used, but capable'of variation in the number of filling cycles per unit of time, a machine in which the quantity entrained in the measuring unit on the intake,v stroke issubstantially completely expelled'therefromy on the discharge stroke at all quantity settings, anda machine in which the formationofgadrop of dispensed iiuid on the end of the'filling needle on completion of -the llingcycle is .automatically eliminated whereby wetting the sides of slender throated containers on entering or withdrawal of the needle is avoided.

Characterizing features of the invention include a variable-.speed variable-throw crank means operatively connected to reciprocate one of the syringe elements-the other of which is mounted for oscillatory movement in a normally xed adjustable slide block. The syringe mounting meansfinclud'es 'also avalve assembly, including twoone-'way acting valves, herein disclosed as g ball checkuvalves, and wherein the syringe cylinder is influid communication with a chamber between the valves'and the intake and delivery-ports; are located respectively at the other sides-;of;the..valves so that as the syringe is actuated fluid-is--drawn-past one ofthe valves into the syringe; cylinderand subsequently discharged `past the lother; valve to the delivery con- ;duit-,and lling'needle.; iThe valve assembly is further vconstructed and arranged automatically to eifect 'a limited-return flow of fluid through the needle 'on completion of `the delivery stroke to thereby draw back intoj the needle 'the final drop of `uidfthatqordinarily would tend to adhere to the end thereof. `By sodrawing-b ack the fluid,v undesirable-.wetting of the throatof the container -as the `needleenters or leaves va containerisy avoidedf--f f v v 'OIthQr-pbjeatsand;advalfitasesl will. b e in Part indicated in the following description and in part rendered apparent therefrom in connection Wit the annexed drawings.

To enable others skilled in the art so fully to apprehend the underlying features hereof that they may embody the same in the various ways contemplated by this invention, drawings depicting a preferred typical construction have been annexed as a part of this disclosure and, in such drawings, like characters of reference denote corresponding parts throughout all the views, of

which: Y

Fig. 1 of the drawings is a side view of a filling machine embodying the invention.

Fig. 2 is a front view of the machine.

Fig. 3 is an enlarged vertical sectional view of a preferred form of valve means incorporating an automatic drop eliminator and drawback feature for the machine. Y e, l

With reference moreA particularly to Figs. '1 and l2 the lling machine disclosed 'comprisesa main frame Amember I0 that provides 'a base. II for a variable-speed geared-.reduction motor I2 and guide ways I3 and Ill forA ,an adjustable slide block I5. The slide block I5 providesljournaling means for a valve assembly I6-to which the cylinder I8 of a standard syringe is detachably se'- cured. The piston I9 ofthe syringe is removably attached to' a variable-throw rotatable crank means indicated at 20, that isdriven by thevmotor I2. The assembly I6 is provided Withan intake port 2 I, a syringe port 22, and a delivery port 23, the latter port being in communication with a delivery conduit 24 -and the lling needle 25. With the severalparts assembled as indicated, operation of the motor will revolve -the crank means and reciprocate the pistomgcausing uid to be drawn into the.syringecylindervia the valve on anvintakeA strokeand discharged through the needle 25 via the valve onadelivery stroke as willbeunderstood. a

v The power source I2 is a4 commercial variable speed motor equipped with a lead cord, built in speed regulator, control knob vI2a, and resistor (not shown) and need not,` itl-is thought, be further described otherthanto state thatthe `output shaft I2b may `b efdriven at selectively variable rates within a range effective to produce approximately 8-to53 fills per hour., The motor Jshaft I2b is adapted to carry land rotate a .crank disc 20a in which a ,radiating .-r-si j2,u b isformed. The T-slotreceives an adjustable-,crankpin 20c, the :latter being formed with --a Tehead adapted to beY clamped in the slot in thedisc/in a selected radial position bymeans of a clampscrewgZUd.

The crank pin 20c is formed with a reduced end portion over which the eye of a syringe adapter stem 26 is slipped when assembling or removing a syringe. The adapter 26 is formed with an externally threaded seat 2l on and about which a syringe clamp collar 2B is threaded. The collar 28 is formed with an inner conical seat adapted to engage behind the head flange of the standard syringe piston for purposes of simultaneously centering and clamping the piston to the seat. When a syringe smaller than the size illustrated herein is to be used, a conical spacer ring (not shown) is employed within the clamp collar 28 to clamp the smaller piston to the adapter seat.

The cylinder of the syringe, which in this instance is the upper member, is detachably connected to the assembly lll with a conventional syringe lock device 2Sl or by other readily `detachable means.

The valve assembly I5 ,is provided with a shaft .3U that extends rearwardly through a journal bearingr 3l pressed into the slide block i5 and is constrained against withdrawal by a collar 32 that overlaps the end of the journal bearing 3l and a `knurled collar screw V33 threading into the shaft 30.

The slide block l5 is provided with parallel guide surfaces 34 which in cooperation with the ways I3, maintains the block properly orientated in any adjusted position on the main frame. A collar screw 3'5 threaded into the slide block vand a collar 3B abutting the rear ways i4, provides convenient means for clamping the slide block in adjusted position. The purpose of the vertically adjustable slide is properly to locate and relate the cylinder of the syringe to the piston regardless of the size thereof or of the stroke imparted by the variable throw crank Zllc. If a small syringe is employede. g. 5 cc. capacity, its overalllength is shorter thana larger capacity syringe, and if it is desired to use only part of the displacement capacity of the small syringe and have the piston reach to the bottom of the cylinder under any stroke .setting of the crank,

the slide Vl5 which supports the cylinder of the I syringe must be adjusted upwardly or downwardly accordingly.

The structure of the yvalve assembly and automatic drop eliminator is disclosed more in detail inFig. 3, in which Ita indicates a one-piece valve body that isqseeurely mounted upon the shaft 3d. The body is vertically bored and reamed to provide a series of coaxial chambers 4B, 4l, 42 and 43 of progressively -decreasing diameter toward the bottom. The Vupper end of the chamber 4d is threaded to receive a knurled collar plug 44 that normally seals the open end thereof. The lower end portion of the chamber 40 is conically formed and leads to the Vnext smaller chamber 4l. The lower end portion of chamber 4l is formed with a conical valve seat Ala that leads into the next lsmaller chamber 42. The lower end of chamber 42 is also formed with a conical valve seat 4m that leads into the next smaller chamber 43, and the latter is in communication with the'supply port 2 I. Ball elements 4 Ib and 42h are contained within the respectivechambers 4l and 42 and cooperate with the seats -to form one-way opening valves. The valve body is also drilled transversely -to provide a delivery port 23 communicating with chamber 40 above the valve therein, and with a port 44 at a point between the two valves so as -to place chamber 42 in communication with the syringe port 22; Port 44 is plugged at its vouter end, asindicated at 45. The line a in Fig. 3 indicates the maximum diameter of the ball 4lb and which is closely but slidably tted to the bore 4E. When the ball Mb is seated on its conical seat 4la, the side walls of the bore 4| extend a slight distance above or axially beyond the diametral plane a of the ball, and to the extent that the bore extends beyond the diameter of the ball it functions as a cylinder and the ball functions as a piston operable within the cylinder. When the ball 4H; is within the cylinder, flow of fluid past the ball in either direction is efectively prevented.

When the piston of the syringe is moving on its intake stroke, a low pressure is created in ports 22, 44 and chamber 42 which causes fluid from the intake line 2| to ow past the ball valve 42h and to enter the syringe cylinder. The upper valve 4i, lila, 4th, remains closed. When the syringe piston moves in its discharging direction, the lower valve 42a, 42h, closes and the ball 4|b of the upper valve is lifted off its seat and with a piston-like movement is moved along and out of the cylinder 4| into the larger chamber 49. When that occurs, the pressure fluid passes around the ball and is expelled through the delivery port 23. On the next following intake stroke of the syringe piston, the upper ball 41h, again falls into the cylinder 4| and seals off the flow. However, by reason of the reduced-pressure then being created in the chamber between the balls 4H) and 42h, the-upper ball vis drawn further into the cylinder until its movement is stopped by the seat Mc, thereupon the lower ball valve becomes solely effective and fluid from the supply line is drawn into the cylinder.

It will be perceived from the foregoing that as soon as the upper Aball Mb, which is in the delivery conduit, reenters the cylinder 4I, flow in either direction past the ball is prevented but inasmuch Vas the-ball then acts as a free piston it continues to -move toward the abutment 41a creating a low pressure zone above it within the chamber 40. In -consequence of this low pressure zone being formed, a portion lof the iluid entrained in the delivery conduits 23, 24, and 25 rushes to ll the chamber. vHence any droplet of fluid that would, under other conditions, hang to the needle end on completion of the delivery, is drawn within the needle a 'limited distance. The extent that the ball Mb is caused to move out of the chamber '40 at the rstart of the intake stroke determines the extent of draw-back within the needle, the greater the piston-like action of the ball the greater will be thedrawback of needle entrained iluid. The Ypreferred practise, however,

is to provide a piston-like movement of only the amount necessary to removev the drop at the needle end `and 'to cause a recession of the fluid from the delivery end of the needle a safe distance to lprevent air contamination.

During normal operation of the machine the syringe H is caused to oscillate by reason ofthe orbital movement imparted by the crank pin 20c, and this oscillatory motion is transmitted to the valve unit. Because ofA this rocking motion it has been found desirable to mount the filling needle rigidly kand to connect the interior of the needle with the delivery port of the valve by means of a flexible hose connection 24. Figs'. 1 and 2 illustrate a preferred needlemount which comprises a support 5llthat is carried by the slidev t5, and `needle adapter 5l detachably secured to the forward endy By "removing the needle adapter and providing alonger hoseoon- -necticn 24, the operator may'manuallyposition the needle in filling relation with successive tubes, vials, ampuls, etc. contained for example in a rack or tray without removing the individual container from the rack. The drawback feature herein explained, operates, it will be understood, to eliminate drop formation with either a mobile or fixed needle.

Without further analysis, the foregoing will so fully reveal the gist vof this invention that others can, by applying current knowledge, readily adapt it for various utilizations by retaining one or more of the features that, from the standpoint of the prior art, fairly constitute essential characteristics of eitherthe generic or specific aspects of this invention and,

therefore, such adaptations should be, and are intended to be, comprehended within the meaning and range of equivalency of the following claims. n g

Having thus revealed this invention, VI claim as new and desire to secure the following ccmbinations and elements, or equivalents thereof, by Letters Patent of the United States:

1. A filling machine of the class described comprising in combination an expansible chamber pump mechanism having an inlet conduit and a delivery conduit and one-way acting valve means in each of said conduits, each of said valves comprising a movable valve element and a cooperating valve seat, each operative alternately to open and close as the pump mechanism is actuated whereby liquid is caused to enter the pump mechanism through said intake conduit and thereafter be discharged through said delivery conduit, an open-ended vfilling needle at the outlet end of said delivery conduit, means operative to vary pump displacement in accordance with the quantity desired to be dispensed by the filling machine on each operating cycle thereof, and means comprising the movable element of the valve means in the said delivery conduit and a portion of the delivery conduit situated on the downstream side of the valve seat responsive to an actuation of the pump mechanism in an intake direction to-'efect a limited reversal of flow in the said delivery conduit with any given pump displacement setting with a consequent limited pull-back of fluid from ,the open end of the needle.

2. A filling machine comprising in combination a measuring pump unit, of the expansible chamber character, valve means connected therewith and with a supply conduit and with a discharge conduit, said valve means comprising a body member having a pair of valve seats formed therein, a ball valve element cooperatively related with each of said seats operative alternately to open and close during the actuation of the pump unit, one of said valve elements and its cooperatively related seat being arranged in the pump intake conduit and the other of said valve elements and its cooperatingk seat being arranged in the pump discharge conduit, an open ended filling needle at the outlet end of said discharge conduit, means operative to vary pump displacement in accordance with the quantity desired to be dispensed by the filling machine on each operating cycle thereof, and means consisting of an element of the valve `means in the pump discharge conduit and a coacting cylinder therefor situated beyond the seat for the ball operative on a reduction in pres-v sure effected'on an intake stroke of the pump unit to seal the discharge conduit from communication with the pump unit prior to the seating of the ball on its seat whereby to effect a limited reversal of fiow of fluid entrained inthe discharge conduit with any givenpump displacement setting With a consequent limited pull-back of fluid from the open end of the needle.

3. In combination with a' variable delivery filling machine having' apisto'n and cylinder type of measuring unit, valve means therefor, intake and 4delivery fluid conduits connected with the valve means, an open ended tubular filling needle connected withthe delivery 'conduit and means to actuate the measuring unit and additional means for varying the` quantity displaced thereby on each operating cycle, means for effecting a draw-back of a constant volume of fluid medium from the'end ofthe filling needle on each' intake stroke of the measuring unit comprising a cylinder element in` fluid' communication at one end with the cylinder -of the measuring unit'andfin fluidcommunication at its other end with said delivery' conduit, means in said second named cylinder operatively responsive to a positive pressure innsaid measuring unit to shift said last'mentioned means open the said second cylinder to ow therethrough to said delivery conduit;andfautoinatically responsive to a negative pressure in said measuring unit to close the saidcylinder tofiow therethrough and thereafter 'to shift v'inthe cylinder a predetermined distance whereby vto produce a negative pressure inthe 'delivery conduit-and a draw-back of fluid entrainedtherein and from the open end of thefilling-needlel y 4. In a lli-ngmachine" embodyingaa Ysyringe for measuring and dispensing a liquid medium, a filling needle connected' therewith and means to actuate the syringe and additional means for varying the unit quantity displaced thereby on each operating cycle, means for effecting a drawback of liquid medium from the end of the filling needle on conclusion of a delivery stroke of the syringe comprising a shiftable piston element movable in an open-ended cylinder formed in the said connection, said cylinder having abutment means at one end thereof adapted to coact with the shiftable piston to limit the movement thereof in one direction and an enlarged chamber at the other end thereof for receiving and containing the piston element when the latter is moved out of its cylinder on a discharge stroke of the syringe whereby to open a fiow passageway to the needle, said shiftable element automatically returning into the cylinder and moving into abutting relation with said abutment means on an intake stroke of the syringe whereby the flow passageway is first closed off and the continued movement of the element' toward the abutment means eects a drawback of a predetermined quantity of the liquid entrained in the needle.

5. A filling machine of the class described comprising an upstanding support, and auxiliary support adjustably mounted to said upstanding support, liquid measuring and dispensing means comprising a piston and cylinder mechanism and inlet and discharge valve means therefor, means mounted to said main support and connected to actuate said piston and cylinder mechanism to effect pumping action, connections between said piston and cylinder mechanism and said valve means for the passage of liquid and between said valve means and a supply `conduit and between said valve means and a delivery conduit, means for varying the stroke of the piston and cylinder mechanism whereby to ef- 7 feet changes in unit quantity displaced on each operating cycle, means mounting the said valve means and one of the elements of said piston and cylinder mechanism to said auxiliary support, and means for adjusting said auxiliary support on said main support to position the parts carried thereby in operative relation with the movable element of the piston `and cylinder mechanism to maintain a given operating relation therewith in all operating strokes, and means in the delivery conduit beyond the zone of normal valving operation .of said valve means operative in conjunction with a part of the discharge valve means to close the conduit'to liquid iiow at the start of an intake cycle of said piston and cylinder mechanism and prior to `the actuation of the discharge valve means to .ncr-

mally closed position. v

6. A lling machine of the character described comprising in combination a measuring unit including a piston element and a cylinder element, crank means connected to reciprocate the piston of the measuring unit, means to vary the throw of said crank whereby to vary the stroke of said piston, means mounting the cylinder of s-aid measuring unit for adjustment relative to the piston whereby to maintain a substantially constant relation between the piston and cylinder at least in one extreme position of reciprocation of the piston throughout the range of stroke adjustment, valve means for the measuring unit comprising `a body member having a stepped bore of progressively diering diameters formed therein, a ball element loosely contained in one of the chambers of the stepped bore and cooperatively related to one end thereof to form a valve, a second ball element fitted piston-like to another of the chambers in said stepped bore and adapted for movement into a third and larger chamber of said stepped bore, a fluid conduit connecting said bore at a region between the said balls therein with the cylinder of said measuring unit, a iiuid intake conduit and a fluid delivery conduit connected with said bore respectively on the other sides of said iii-st and second mentioned balls, said second mentioned ball responding to a positive pressure in the cylinder to move out of its chamber into said larger chamber whereby to permit a iioW through the delivery conduit and operatively responsive to a negative pressure in the cylinder to move into its closely tting chamber and operate as a piston therein whereby to draw back a predetermined quantity of the iiuid entrained in the delivery conduit, said draw back of fluid remaining constant in quantityl under all stroke settings of measuring unit. y

FRAllI J. COZZOLI.

REFERENCES `errar) The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 688,306 Hardie Dec. 10, 1901 963,801 Nader July 12, 1910 1,389,547 Eger Aug. 30, 1921 2,150,760 Cozzoli Mar. 14, 1939 2,234,932 Schlaupitz Mar. 11, 1941 2,415,419 Cozzoli Feb. 11, 19117

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