US3733773A

US3733773A - Apparatus including reciprocating web feeding means for a continuously feeding web

Info

Publication number: US3733773A
Authority: US
Inventors: J Hamilton
Original assignee: RA Jones and Co Inc
Current assignee: RA Jones and Co Inc
Priority date: 1971-05-27
Filing date: 1971-05-27
Publication date: 1973-05-22
Anticipated expiration: 1990-05-22
Also published as: IT957985B; DE2226456A1; FR2139141B1; GB1398984A; FR2139141A1

Abstract

A blister packaging machine is provided with a pair of alternating reciprocating clamps which feed a web of sheet material in a continuous motion through the machine by alternately engaging the web by the clamps during the advancing portions of their strokes and transferring engagement back and forth between the clamps while the clamps are moving forwardly at the same velocity. The clamps are driven by a cam and cam follower mechanism linked to the clamps. A movable flat bed work station is supported for movement with one of the clamps and has a working member which works upon the sheet by a reciprocating stroke against the sheet. The actuation of the clamps, the motion of the clamps, and the timing of the actuation of the working elements is derived from the cam mechanism. The machine is particularly useful in forming blister packages for pills and the like through the use of reciprocating dies.

Description

United States Patent 1 Hamilton 1 May 22,1973

[54] APPARATUS INCLUDING Primary Examiner-Travis S. McGe hee RECIPROCATING WEB FEEDING Att0rney-Wood, l-lerron & Evans MEANS FOR A CONTINUOUSLY FEEDING WEB 7] AB TRA T [75] Inventor: Joel A. Hamilton, Englewood, NJ. A blister packaging machine is provided with a pair of alternating reciprocating clamps which feed a web of [73] Asslgnee if? & Company sheet material in a continuous motion through the g machine by alternately engaging the web by the [22] Filed: May 27, 1971 clamps during the advancing portions of their strokes and transferring engagement back and forth between [21] Appl 147507 the clamps while the clamps are moving forwardly at the same velocity. The clamps are driven by a cam U-S. Cl. and cam follower mechanism to the clamps A 425/333 movable flat bed work station is supported for move- CI- v B65b ment one of the clamps and has a Fleld of Search member works upon the sheet a reciprocat- 226/112; 83/277; 425/383 ing stroke against the sheet. The actuation of the clamps, the motion of the clamps, and the timing of [56] References cued the actuation of the working elements is derived from the cam The machine is particularly u scful in forming blister packages for pills and the like :iegerist through the use of reciprocating dies troop 21 Claims, 9 Drawing Figures 1 a 59/ MAI/M472 10/90 F91? #677 if j 4- a f 3 t w -3/- -33 vt -aa- ,r

f v ,5; i F 4/ 3/ A PATENIEWw 3,733,773

SHEET 1 [1F 4 INVENTO PATENTEU HAY 2 2 I973 SHEET 2 OF 4 PATENTED 2 2 3 SHEET [1F 4 INVENTQR.

APPARATUS INCLUDING RECIPROCATING WEB FEEDING MEANS FOR A CONTINUOUSLY FEEDING'WEB The present invention relates-to apparatus for working upon continuously moving webs of sheet material with reciprocating flat bed working elements and more particularly to the feeding of a continuously moving sheet material through packaging machines and the coordinating of the movements of the working elements therewith.

An increasingly common and widespread means of packaging small articles which are to be sold in small quantities is to package the articles in what is commonly referred to as blister packages. Such packages are finding extensive use in the packaging of pills of capsule and tablet form. These packages are fabricated from thermoplastic sheet material in which individual compartments resembling bubbles or blisters have been formed. The articles are individually packaged in each of the compartments which are then hermetically sealed by the lamination of another plastic or foil material film over the sheet. Pills, for example, packaged in this manner are thus protected from deterioration due to contact with air and moisture. When the pills are needed, they can be individually withdrawn from their respective compartments by the breaking of the seal through the laminated film.

The manufacture of the blister packages in its most economical form involves thermoforming the blister compartments in the thermoplastic sheet which is supplied in the form of a continuous web wound in a roll. The process used involves the feeding of the sheet material in the roll past the series of work stations in which successive operations are performed. These operations result in the forming of the blister compartments, the loading of articles into the compartments, and then the sealing of the compartments, usually by the laminating of film also supplied from a roll. The loaded and sealed blister packages are then cut into packages of convenient quantities of articles.

The series of work stations is usually arranged so that first heat is applied to the thermoplastic sheet to soften it, and then immediately thereafter the sheet is brought into contact with forming dies which shape it. These dies may include a mating die pair which is brought together against the sheet from opposite sides of the sheet, or may include a single forming die in which pneumatic force is applied in the form of high pressure air or a vacuum to deform the sheet into the single die. After the blisters are thus formed, the articles are loaded by passing the web through a loading station which includes a filling machine such as a pill dropper.

The loaded compartments are then passed to a laminating station in which a film material is laminated to seal the compartments. The film is usually a web supplied from a roll, and may be either thermoplastic material, a metallic foil, or one of several other suitable materials. The lamination may involve the application of heat to cause the second film to adhere to the sheet, but, frequently, the film is laminated through the application of an adhesive. This process involves the passing of the loaded sheet through an adhesiveapplying station and then a pressure laminating station. After the lamination is completed, the loaded and sealed blister packages are passed to a die station in which movable cutting dies are brought into contact with the sheet to sever the sheet into individual article containing packages.

In performing the operations which form the final package, the sheet must be fed through the successive work stations. This may be done by continuously moving the sheet and designing the work stations in such a manner that they can effectively operate on the moving sheet. Alternately, the sheet may be intermittently advanced through the work stations which may be designed to effectively operate upon the sheet during dwells in the feeding operation. I

From an operating point of view, a continuous feeding process is more desirable in that it can be performed faster and in that it eliminates problems involved in accelerating and decelerating the sheet material which usually is not structurally resistant to deformations or tearing which customarily result from such accelerations. The continuous feeding process, however, usually requires very expensive work stations. For example, the die forming station usually must include dies which engage the sheet through a considerable portion of its movement along the path. A common type of die used for this is a rotating die which employs individual die members mounted on the surface of a rotating cylinder. Such dies must be synchronized in their operation so that their speed conforms identically with that of the moving web. These dies are relatively expensive, and because these are frequently interchanged to accommodate various package sizes and configurations, provision for a great number of such rotatable dies involves a considerable expense.

One'of the conventional means employed in driving the web in a continuous manner through such a machine has been to use continuously moving feed rolls of the pinch roll type. Experience with these rolls, however, has found that a minor amount of slippage does occur which makes coordinating the motion of the dies and the web extremely difficult and somewhat unsatisfactory.

When cheaper, planar or flat bed work members are used, it is necessary that these members reciprocate in some manner in a path parallel to the moving web. In all prior art devices, it has been found considerably difficult to effectively coordinate the velocity of the reciprocating members such as dies with that of the continuous moving web.

In intermittent web motion type machines, the sheet handling has been somewhat unsatisfactory in that the varying motion of the sheet into the work station coupled with the motion of the somewhat heavy and high inertia supply rolls puts great stress upon the sheet, and frequently results in the tearing or deforming of the sheet. In order to alleviate this problem to a degree, and to provide for continuous rotation of the supply roll and intermittent feed of the web through the work stations, complicated festooning devices have been incorporated involving clutch and brake devices, etc. These devices have not entirely eliminated the web handling problems and have added other design problems, particularly relating to the varying of the sizes of the packages and the length of the feeding strokes. Other disadvantages of intermittent web motion type machines lies in the handling of the articles which tend to jump in higher speed operations. Liquid materials pose a particularproblem in this regard.

In addition to die forming work stations, similar difficulties have been found in connection with other oper- 3 ations such as the heating operation, the laminating operation, and the die cutting operation.

To overcome the disadvantages of the prior art, it is a principle objective of the present invention to provide, particularly in a packaging machine, simple and reliable means for continuously feeding the sheet mate rial and for precisely and positively synchronizing the motion of reciprocating flat bed work stations with the continuous motion of thematerial.

It is a more specific objective of the present invention to provide a simple and effective reciprocating mechanism to impart a continuous feeding motion to the web, and to drive reciprocating work stations at exactly the same speed as the moving web when they are working upon the web.

It is another objective of the present invention to provide a low cost flexible machine in which a positive mechanical drive mechanism and positive mechanical linkages move both the web feeding elements and the work stations in unison.

The present invention is predicted in part upon the concept of imparting a continuous motion to a web by feeding the web through alternating intermittent engagement of the web by oppositely moving reciprocating feed members. The present invention is further predicted upon the concept of providing movable flat bed work stations mechanically linked to one of the feed members and actuating it upon the forward portion of the feeding stroke so that the web will move at precisely the same velocity as the feed member. The work station is actuated only when the feed member is positively engaging the sheet to insure that there is no slippage between the sheet and the working elements.

In the preferred embodiment of the invention, a blister packaging machine is provided with a pair of reciprocating clamps, each actuable to engage the sheet and to move it along its path. The clamps are driven through mechanical linkages which are in turn driven by a rotating cam. The clamps are timed so that, in alternating fashion, one will advance the sheet while the other of the clamps is being returned to its initial position. The clamps are further timed to provide that feeding engagement of the web is transferred from one clamp to the other clamp at a time whenthe clamps are moving with the same forward velocity. The work stations are coupled to either one of the clamps and are actuable only when the respective clamp to which it is so coupled is engaged so that the respective work station is always moving at precisely the same velocity as the associated clamp, and thus the precise velocity as the web upon which it is operating.

The advantages of the invention reside in the positive and reliable means for ascertaining continuous web motion, in the ability to use simple and economical work station components, and in the ease in adapting the machine to products of differing sizes.

These and other-objectives and advantages of the present invention will be more readily apparent from the following detailed description of the drawings illuschine embodying principles of the present invention, in which:

FIG. 1 is a perspective view of a pill blister package which the present invention is useful in producing;

FIG. 2 is a block diagram of a blister packaging machine embodying principles of the present invention;

trating one preferred form of blister packaging ma- FIG. 3 is an elevational view of the preferred embodiment of the machine of FIG. 2; 7

FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. 3 illustrating the mounting of the vertically reciprocatable heads in the work stations;

FIG. 5 is a cross-sectional view taken along line 55 of FIG. 3 illustrating the'head actuating mechanism;

FIG. 6 is an elevational view of the head actuating mechanism of FIG. 5 illustrating the mechanism in the head released condition;

FIG. 7 is a longitudinal cross-sectional view, partially broken away, illustrating the relative mountings of the clamps;

FIG. 8 is a diagram of the cam which imparts horizontal reciprocating motion to the clamps and machine head assemblies; and

FIG. 9 is a timing diagram illustrating the operation of the machine set forth in the figures above.

GENERAL DESCRIPTION A typical blister pack 10, as illustrated in FIG. 1, includes, for example, twelve compartments 11 which are formed in a thermoplastic sheet 12. Each of the compartments 11, when forming a filled package 10, contains usually one pill 14. The compartments 11 are hermetically sealed by a film 16 which is laminated to the sheet 12 to close the open ends of the compartments 1]. According to one preferred embodiment of the present invention, such packages are manufactured on an apparatus as illustrated in the block diagram of FIG. 2.

Referring to FIG. 2, a pill blister packaging machine 20 is illustrated in block diagram form having a supply roll 21 upon which is wound a web of the thermoplastic sheet material 12. The machine defines a web directing path 22 which the web of material 12 follows through the machine 20 from the supply roll 21 to the discharge end 24 of the machine 20. The machine 20 is provided with a plurality of work stations 30 which include a heating station 31 positioned nearest the upstream end of the machine 20 near the supply roll 21. The second work station is a deforming station 32 positioned adjacent the heater station 31 to the downstream end thereof. The heater station 31 includes work elements which apply heat to the sheet as it passes through the station to soften the material 12 in order to condition it for deformation at the die forming station 32. The die forming station 32 includes at least one die having a die element which defines the shapes of a compartment or set of compartments 11 which will be part of the package 10. These compartments may include a pair of die members which move together from opposite sides of the material 12 to form the blisters or bubble compartments 11 in the sheet material 12. In accordance with the present invention, these die elements are reciprocating die elements which move together in a path perpendicular to that of the sheet material 12.

The sheet 12 which emerges from the work station 32 is passed to a work station 33 which is a pill dropper which operates to insert pills into the individual com- I. partments 11 formed in the sheet 12. The sheet containing the filled compartments is then advanced to a laminating station 34 which applies the film 16 to seal the pill compartments. The film 16 is supplied in web form from a roll 17 and is directed around a roll 18 into a path overlying the sheet 12. The station 34 operates either by a roll contact or preferably by a stamping motion to secure the film 16 to the sheet 12. The sealed compartments are then advanced to a cutting station 35 which contains preferably a set of die cutting elements which move together in a reciprocating path to both cut the packages into individual discrete sets of pill compartments and to score the packages for folding, if desired. The packages emerging from the station 35 are completely formed packages 10 and are discharged from the discharge end of the machine 24.

While all of the work stations 30 may be of conven tional design, the present invention is provided with the aim of allowing for the use of reciprocating type work elements with the maximum of convenience and reli ability. Accordingly, when such elements are incorporated in any of the work stations 30, the present invention provides a means of insuring that, while the work station is actuated, it is moving at precisely the same speed as the sheet 12 upon which it is operating.

Accordingly, the present invention provides sheet advancing units which employ two pairs of elongated clamping

elements

41 and 42 adapted to grip the edge of the sheet 12 along an extended portion of its length and to move it in a forward direction through the machine 10. Each of the pairs of

clamps

41 and 42 are individually but synchronously driven in reciprocating movement along the path 22 by a cam drive unit 43. The cam drive unit 43 serves to separately drive the

clamps

41 and 42 through linkages 44 and 45, respectively. The pairs of

clamps

41 and 42 are driven at an approximately constant velocity through an advancing stroke of relatively long duration. Each clamp is retracted during a return stroke of shorter duration, with one clamp pair being retracted while the other is being advanced. In this manner, the advancing strokes of the clamp pairs will overlap so that they will both be moving forward at the same velocity, preferably at approximately the same velocity as the constant forward velocity attained during most of the forward portion of the advancing stroke. During the advancing stroke, the clamp is engaged, while during the returning stroke the clamp is disengaged. Both clamps, however, are simultaneously engaged'momentarily at the beginning and end portions of the strokes during which they are both moving forward at the same constant velocity. During this momentary period, engagement is transferred from one clamp to the other to feed the web in a smooth and uniform manner through the machine 10. It will be seen from discussion herein and which follows that it will not be absolutely essential that the advancing of the sheet be perfectly uniform. This is primarily due to the fact that the work stations, when operating, will always be moving at precisely the same speed as the advancing web due to its positive and direct link to the advancing clamp.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT Referring to FIGS. 3 and 4, the pill packing machine which was illustrated diagrammatically in FIG. 2 is shown in detail. Four of the five work stations 30 are shown as carried upon two machine head assemblies 71 and 72. Each of these assemblies includes a lower head 73 and an upper head 74, each slideably mounted to move vertically upon the machine head assemblies. Each of the assemblies 71 and 72 includes a vertical support plate 76 pivotally mounted at its lower end to the machine frame 77 through a pivotal axis 78. The

upper end of the plate 76 is rigidly attached to a cross plate 79. A T-shaped link 81 is pivotally mounted at its cross point by a pin 82 to the plate 76. To the lower portion of the T-shaped link 81 is slideably mounted the lower machine head 73 through a bracket 83. The upper machine head 74 is slideably mounted to the upper extension of the link 81 by slideable bearing blocks 85 which are mounted in a groove 86 of the upper member of the link 81. The remote end of the horizontal portion of the link 81 is pivotally attached at point 88 to a vertical bar 89 which is in turn pivotally mounted to the frame 77 at point 90. The frame 77, the plate 76, the link 81, and the bar 89 form a parallelogram which will maintain the orientation of the

heads

72 and 73 in a vertical attitude.

This parallelogram configuration of the machine head assemblies 71 and 72 are rocked in a reciprocating manner through linkages 92 attached to rocker arms 93 which carry cam followers 94 and 95 which are driven by a cam 96 (FIG. 8). The reciprocating stroke is actually an are but it is relatively short compared to the length of the plate 76 and the bar 89. Thus, the vertical motion is insignificant and the motion is substantially horizontal. The stroke length is varied by remounting the link 92 between

different holes

84 and 87 in the

members

76 and 93, respectively.

The raising and lowering of the upper and lower machine heads 74 and 73 are achieved through linkages 91 which are driven by rocker arms 97 carrying the cam followers 98 and 99 respectively, which are driven by the cam 100. The details of the mechanism for raising and lowering these

heads

73 and 74 will be understood more clearly in connection with FIGS. 4 and 5 below. While a mechanical actuator is shown, it is contemplated that other means such as electrical, hydraulic, or pneumatic actuators could be used satisfactorily since this motion need not be critically maintained.

The mounting of the work stations 31-35 are as follows: the heater station and the die forming station are both mounted to the heads of the machine head assembly 71 and move in unison under the control of the cam follower 99. The loader 33 may be any conventional pill dropper and is positioned downstream from the machine head assembly 71. The laminating station and the trimming

station

34 and 35, respectively, are mounted to the machine head assembly 72 and move in unison under the control of the cam follower 98. The

clamps

41 and 42 extend longitudinally of the machine 20 along the path 22 of the sheet 12. The outer clamp 42 is pivotally supported at the machine head assembly 71, while the inner clamp 41 is pivotally supported at the machine head assembly 72. The

clamps

41 and 42 are slideably mounted with respect to each other and therefore support each other in a horizontal orientation, but each moves individually in unison with the machine heads 71 or 72 to which they are pivotally mounted.

The machine head actuating mechanism is best shown in FIGS. 4-6 with reference also to FIG. 3. FIG. 4 illustrates the machine head assembly 72 with the

heads

73 and 74 in the actuated or closed position. As shown, the head assembly 72 includes the rigidly coattached vertical and

top plates

76 and 79. To the side plate 76 is slideably mounted the upper head 74 through the slide bearing assembly 85 which rides in the slot 86 in the T-shaped link 81 which is pivotally attached at point 82 to the plate 76. The lower head is similarly slideably mounted with respect to the plate 76. This slideable mounting is achieved through the rigid mounting to the bracket 83 which slideably engages the T-shaped member 81. The lower head 73 is driven up and down through the lower head drive link 105 which is pivotally mounted to the lower head support bracket 83 through the pivot shaft 106. Similarly, the upper head 74 is driven by the upper head drive link 107 which is pivotally mounted to the upper head 74 by the shaft 108.

The

links

105 and 107 are driven by the head actuating mechanism shown in FIGS. and 6. Referring to these figures, a torsion bar 121 is supported on the pivot shaft 78. A lever 122 is rigidly secured to the center of the torsion bar and linked through the linkage 91 to the rocker arm 97 to be driven by the cam follower 98. Secured to the ends of the torsion bar 121 are levers 124 which are pivotally attached to the lower end of the lower head drive rods 105. The lower ends of the upper head actuator rods 107 are pivotally attached by a pin 126 to the end of the torsion bar 121. When the head is in its actuated position, the pin 126 is directly below the shaft 78. In FIG. 3, the head assembly 72 is illustrated in the head actuated condition, while the head 71 is illustrated in the head de-actuated or released condition.

Referring again to FIG. 4, the clamp structure is illustrated in which the clamps are arranged in a superimposed relationship with an inner clamp 51 spaced along the edge of the sheet 12 and surrounded by the outer clamp 52. Each of the clamps form one corresponding clamp of each of the pairs of clamps which are arranged in corresponding positions on opposite sides of the web 12 to simultaneously grip the edges thereof. The inner clamps 51 make up the clamp pair 41, while the outer clamps 52 make up the clamp pair 42.

Each inner clamp 51 includes a relatively fixed element 53 and a movable clamp element 54 which is spring mounted through the integrally formed spring 55 secured to the wall 56 of the clamp to which the relatively stationary element 53 is an integral part. The spring element 55 normally biases the movable clamp element 54 away from the fixed element 53 to thereby release the sheet 12. The clamp 51 is actuated to grip the sheet 12 by the inflation of an elastic hose 57 positioned within the curve of the spring 55 to urge the movable element 54 toward the fixed element 53. The inner clamp 51 is slideably mounted to the outer clamp 53 by bolts 58 extending through a slot 59 and secured to the inner clamp drive bar 60.

Each outer clamp 52 includes a relatively fixed element 63 and a movable clamp element 64 which is spring mounted through the integrally formed spring 65 secured to the wall 66 of the clamp 52 to which the relatively stationary element 63 is an integral part. The spring element 65 normally biases the movable clamp element 64 away from the fixed element 63 to'thereby release the sheet 12. The clamp 53 is actuated to grip the sheet 12 by the inflation of an elastic hose 67 positioned within the curve of the spring 65 to urge the movable element 64 toward the fixed element 63.

The clamp assemblies are supported from a bracket 131 suspended from the upper plate 79 and each of the machine head assemblies 71 and 72. As illustrated in FIG. 4, the bracket 131 is driveably connected through a pivot pin 132 to the slide bar 60 to -drive the inner clamp 41. However, at the station 71, the bracket 131 would be driveably connected to the clamp 42 with the pivot shaft 132 extending through a slot in the slide bar 58 and engaging the wall structure of the clamp 42. The slideable mounting of the

clamps

41 and 42 with respect to each other is illustrated more clearly in connection with FIG. 7. As illustrated, the slide bar 60 and the back plate 133 of the outer clamp are slideably supported by each other through combinations of slide bearings 137 secured to one of the

members

60 or 133 and adapted to slide in a slot 59 of the other of these members. Accommodation of different web widths is achieved by the mounting of the bracket on the top plate 99 by setting the screw 124 at different points along the slot 128.

The operation of the machine can best be understood by reference to FIGS. 8 and 9, which illustrate the relation of the

cams

96 and 100 in connection with the machine functions. Referring to cam 96, six regions are illustrated. Three of these

regions

141, 142, and 143, illustrate a region of continuously increasing radius through which the cam followers 94 and 95, and consequently their respective driven heads and clamp members, will be moving in a forward direction at a uniform velocity. As can be seen, the combined region spans an arc of more than 180. The

regions

141 and 143 thus represent the regions which the cam followers 94 and will both be moving the same direction with the same velocity. When the cam followers 94 and 95 are within this region, the actuation and de-actuation of the clamps will occur as will be seen in connection with the timing diagram of FIG. 9. During the time in which the cam followers 94 and 95 are within the

cam regions

145 and 146, the cams and their associated driven elements will be accelerating and decelerating, respectively to or from their forward movement. The region 147 represents the region in which the elements will be moving in the reverse direction and returning to their initial positions.

The cam is a groove type cam which has essentially two operating radii, the first or larger radius spans the major portion of the cam and represents the condition in which the heads will be de-actuated or in their opened condition. The lower portion therefore represents the region in which the heads will be in their closed or actuated condition. These regions aredesignated 151 and 152, respectively, in FIG. 3.

The timing diagram of FIG. 9 illustrates the various machine functions including the head and clamp horizontal motion as controlled by the cam 96, the head vertical reciprocating motion as controlled by the cam 100, and the actuation of the

clamp assemblies

41 and 42 controlled by other cams not shown on the shaft of the

cams

96 and 100. The timing relationships are illustrated with respect to the top dead center position of the cam assembly. Curve A represents the relative horizontal position of the machine head assembly 72 and the inner clamp 41 as driven by the cam follower 94. Curve 8 illustrates the relative horizontal position of the heads 71 and the outer clamp 42 as driven by the cam follower 95. Curve C represents the actuated condition of the clamp 41, while curve D represents the actuated condition of the clamp 42. Curves E and F represent the closed or actuated conditions of the head assemblies 72 and 71, respectively, as controlled by the cam followers 98 and 99 respectively. The machine, in all the figures, is illustrated in the condition in which the cam is in top dead center as illustrated by the left hand vertical coordinate of the timing diagram of FIG.

What is claimed is:

1. A machine for forming, filling, and sealing packages from a web of material being continuously transported past a series of work stations, said machine comprising:

means for continuously advancing said web along a path past said work stations including:

a. a pair of clamp assemblies each adapted to engage said web,

b. means for mounting said clamp assemblies for reciprocating movement in forward and reverse strokes'along said path, I

c. a rotatable cam,

d. a pair of cam followers,

e. means for linking each of said cam followers to a different one of said clamp asse'mblies,'ari'd f. said cam and cam followers being adapted to reciprocate said clamp assemblies in an out-ofphase relationship with each other;

at least one of said work stations mounted for reciprocating movement with one of said clamp assemblies; V v

said movable work station including flat bed working elements movable with respect to said work station in a path approximately perpendicular to that of ,said web and the movement of said work station;

means for actuating said working elements to work upon said web while the clamp assembly with which the work station is mounted is engaging and advancing said web; and

clamp actuating means for alternately closing said clamp assembliesduring a portion of their forward strokes, said clamp assemblies being simultaneously closed only when moving at the same velocity during the forward stroke; I

whereby said web is continuously moved in a forward direction by the alternative action of said clamp assemblies.

2. A machine according to claim 1 I wherein said working elements include:

a reciprocating die assembly operable to deform said web when actuated.

3. A packaging machine having forming, filling, and sealing means for working upon a continuous web of sheet material, said machine comprising? means for directing said web in a predetermined path;

a flat bed work station positioned along said path;

means for continuously advancing said web in a forward direction along said path past said work station, said advancing means including first and second feed elements, each of said feed elements being mounted for reciprocating movement along said path and each being adapted to intermittently engage and advance said web durin g the forward motion of the element; and

drive means for alternately reciprocating said feed elements, said drive means including a mechanical linkage connected between said feed elements.

4. A machine according to claim 3 wherein:

said work station is fixedly linked to one of said feed elements for reciprocating movement therewith.

5. A machine according to claim 4 wherein said work station includes:

a working member for working upon said web and mounted for reciprocating movement on said movable work station in a path approximately perpendicular to the path of said web and said work station.

6. A machine according to claim 5 further comprising:

means for actuating said working element to work upon said web while the sheet feed member with which thework station is mounted is engaging and advancing said web.

7. A machine according to claim 3 further comprising:

means'for actuating said feed elements to engage said web during the forward movement of the element but to disengage said web during the return movement of the feed element;

said feed elements being moved at the same velocity in the forward direction during periods near the beginnings and the ends of their forward movements, said elements momentarily simultaneously engaging said web during said periods;

whereby said web is continuously being engaged and advanced by at least one of said elements.

8. A machine according to claim 7 wherein:

said elements are driven at an approximately constant velocity when engaging said web.

9. A blister packaging machine comprising:

a supply of thermoplastic sheet material in the form of a web; I i i a plurality of work stations for successively performing, upon said web,'the operations 'of l. heating a portion of said web,

2. deforming a heated portion of said web to form a plurality of blister-like compartments therein,

3. loading articles into said formed compartments,

4. laminating a film to a portion of said web to seal said loaded compartments, and

5. trimming a sealed portion of said web to form a package;and

meansfor continuously advancing said web along a 'path past said work station comprising:

a. a pair of clamp assemblies adapted to engage 'said web,

b. means for mounting said clamp assemblies for reciprocating movement in forward and reverse strokes along said path,

c. a rotatable cam,

d. a pair of cam followers,

e. means for linking each of said cam followers to a different one of said clamp assemblies,

f. said cam and cam followers being adapted to reciprocate said clamp assemblies in out-of phase relationship with each other; and

g. clamp actuating means for alternately closing .said clamp assemblies during a portion of their forward strokes, said clamp assemblies being simultaneously actuated only when moving at the same velocity during the forward stroke; whereby said web is continuously moved in a forward direction by the alternative action of said clamp assemblies.

10. A machine according to claim 9 wherein:

at least one of said work stations mounted for reciprocating movement with said clamp assemblies;

said movable work station including working elements movable with respect to said work station in II. A machine according to claim wherein said movable work station includes:

a die forming assembly having an element movable against said web to deform said web while said station is moving at the same velocity as said web.

12. A machine according to claim 10 wherein said movable work station includes:

a heater assembly having an element movable against said web to heat said web while said station is moving at the same velocity as said web.

13. A machine according to claim 10 wherein said movable work station includes:

a press assembly having an element movable against said web to laminate to said web an interposing film material while said station is moving at the same velocity as said web.

14. A machine according to claim 10 wherein said movable work station includes:

a die cutting assembly having an element movable against said web to cut said web while said station is moving at the same. velocity as said web.

15. in a machine for working upon a web ofsheet material at awork station, means for continuously advancing said web along a path past said work station com-. prising:

a pair of clamp assemblies adapted to engage said web;

means for mounting said clamp assemblies for reciprocatingmovement in forward and reverse strokes along said path,

a rotatable cam;

a pair of cam followers;

means for linking each of said cam followers to a different one of said clamp assemblies;

said cam and cam followers being adapted to reciprocate said clamp assemblies in out-of-phase relationship with each other; and

clamp actuating means for alternately closing said clamp assemblies during a portion of their forward strokes, said clamp assemblies being simultaneously actuated only when moving at the same velocity during the forward stroke;

whereby said web is continuously moved in a forward direction by the alternative action of said clamp as-. semblies. v

16. Advancing means according to claim 15 wherein:

each of said clamp assemblies includes a pair of elongated clamps extending along said path and on opposite edges of said web, said clamp assemblies being positioned to engage said edges when closed.

17. Advancing means according to claim 15 wherein:

said cam includes a major portion of uniformly increasing radius; and

said cam followers are positioned at diametrically opposite points on said cam.

18. A method for continuously advancing. a web of sheet material through a machine having at least'one work station for intermittently operating on said sheet material comprising the steps of:

engaging said sheet with a first engaging element and feeding said sheet a given distance through said machine with a forward stroke of a first engaging element;

then engaging said sheet with a second engaging element which is moving at the same velocity as said first engaging element near the end of its advancing stroke, and thereafter releasing said sheet by said first engaging element;

then returning said first engaging'element to the beginning of its stroke while advancing said sheet with said second engaging element a second given distance along said path;

then re-engaging said sheet with a first engaging element which is moving at the same velocity as said second engaging element near the end of its advancing stroke, and thereafter releasing said sheet by said second engaging element;

and moving said work station at the same velocity and direction as said sheet during the intervals that said work station is operating on said sheet.

19. A method according to claim 18 for continuously advancing a web of sheet material through a machine having at least one work station for intermittently operating on said sheet material comprising the steps of:

successively performing the steps set forth in claim 18 a plurality of times. 20. A machine for working upon a continuous web of sheet material comprising:

means for directing said web in a predetermined path; a work station positioned along said path; means for continuously advancing said web in a forward direction along said path past said work station, said advancing means including first and second feed elements, each of said feed elements being mounted for reciprocating movement along said path and each being adapted to intermittently engage and advance said web during the forward motion of the element; said work station being fixedly linked to one of said feed elements for reciprocating movement therewith, and drive means for alternately reciprocating said feed elements, said drive means including a mechanical linkage connected between said feed elements. 21. Apparatus comprising a supply of material in web form, a reciprocable work station for performing at least one operation on said web, at least one reciprocable gripper for grasping said web and advancing it past said work station, a single cam, and means connecting said single cam to both said work station and said gripper to reciprocate said work station and gripper.

Claims

1. A machine for forming, filling, and sealing packages from a web of material being continuously transported past a series of work stations, said machine comprising: means for continuously advancing said web along a path past said work stations including: a. a pair of clamp assemblies each adapted to engage said web, b. means for mounting said clamp assemblies for reciprocating movement in forward and reverse strokes along said path, c. a rotatable cam, d. a pair of cam followers, e. means for linking each of said cam followers to a different one of said clamp assemblies, and f. said cam and cam followers being adapted to reciprocate said clamp assemblies in an out-of-phase relationship with each other; at least one of said work stations mounted for reciprocating movement with one of said clamp assemblies; said movable work station including flat bed working elements movable with respect to said work station in a path approximately perpendicular to that of said web and the movement of said work station; means for actuating said working elements to work upon said web while the clamp assembly with which the work station is mounted is engaging and advancing said web; and clamp actuating means for alternately closing said clamp assemblies during a portion of their forward strokes, said clamp assemblies being simultaneously closed only when moving at the same velocity during the forward stroke; whereby said web is continuously moved in a forward direction by the alternative action of said clamp assemblies.

2. A machine according to claim 1 wherein said working elements include: a reciprocating die assembly operable to deform said web when actuated.

3. A packaging machine having forming, filling, and sealing means for working upon a continuous web of sheet material, said machine comprising: means for directing said web in a predetermined path; a flat bed work station positioned along said path; means for continuously advancing said web in a forward direction along said path past said work station, said advancing means including first and second feed elements, each of said feed elements being mounted for reciprocating movement along said path and each being adapted to intermittently engage and advance said web during the forward motion of the element; and drive means for alternately reciprocating said feed elements, said drive means including a mechanical linkage connected between said feed elements.

3. loading articles into said formed compartments,

4. A machine according to claim 3 wherein: said work station is fixedly linked to one of said feed elements for reciprocating movement therewith.

5. A machine according to claim 4 wherein said work station includes: a working member for working upon said web and mounted for reciprocating movement on said movable work station in a path approximately perpendicular to the path of said web and saId work station.

5. trimming a sealed portion of said web to form a package; and means for continuously advancing said web along a path past said work station comprising: a. a pair of clamp assemblies adapted to engage said web, b. means for mounting said clamp assemblies for reciprocating movement in forward and reverse strokes along said path, c. a rotatable cam, d. a pair of cam followers, e. means for linking each of said cam followers to a different one of said clamp assemblies, f. said cam and cam followers being adapted to reciprocate said clamp assemblies in out-of-phase relationship with each other; and g. clamp actuating means for alternately closing said clamp assemblies during a portion of their forward strokes, said clamp assemblies being simultaneously actuated only when moving at the same velocity during the forward stroke; whereby said web is continuously moved in a forward direction by the alternative action of said clamp assemblies.

6. A machine according to claim 5 further comprising: means for actuating said working element to work upon said web while the sheet feed member with which the work station is mounted is engaging and advancing said web.

7. A machine according to claim 3 further comprising: means for actuating said feed elements to engage said web during the forward movement of the element but to disengage said web during the return movement of the feed element; said feed elements being moved at the same velocity in the forward direction during periods near the beginnings and the ends of their forward movements, said elements momentarily simultaneously engaging said web during said periods; whereby said web is continuously being engaged and advanced by at least one of said elements.

8. A machine according to claim 7 wherein: said elements are driven at an approximately constant velocity when engaging said web.

9. A blister packaging machine comprising: a supply of thermoplastic sheet material in the form of a web; a plurality of work stations for successively performing, upon said web, the operations of

10. A machine according to claim 9 wherein: at least one of said work stations mounted for reciprocating movement with said clamp assemblies; said movable work station including working elements movable with respect to said work station in a path approximately perpendicular to that of said web and the movement of said work station; and means for actuating said working elements to work upon said web while the clamp assembly with which the work station is mounted is engaging and advancing said web.

11. A machine according to claim 10 wherein said movable work station includes: a die forming assembly having an element movable against said web to deform said web while said station is moving at the same velocity as said web.

12. A machine according to claim 10 wherein said movable work station includes: a heater assembly having an element movable against said web to heat said web while said station is moving at the same velocity as said web.

13. A machine according to claim 10 wherein said movable work station includes: a press assembly having an element movable against said web to laminate to said web an interposing film material while said station is moving at the same velocity as said web.

14. A machine according to claim 10 wherein said movable work station includes: a die cutting assembly having an element movable against said web to cut said web while said station is moving at the same velocity as said web.

15. In a machine for working upon a web of sheet material at a wOrk station, means for continuously advancing said web along a path past said work station comprising: a pair of clamp assemblies adapted to engage said web; means for mounting said clamp assemblies for reciprocating movement in forward and reverse strokes along said path, a rotatable cam; a pair of cam followers; means for linking each of said cam followers to a different one of said clamp assemblies; said cam and cam followers being adapted to reciprocate said clamp assemblies in out-of-phase relationship with each other; and clamp actuating means for alternately closing said clamp assemblies during a portion of their forward strokes, said clamp assemblies being simultaneously actuated only when moving at the same velocity during the forward stroke; whereby said web is continuously moved in a forward direction by the alternative action of said clamp assemblies.

16. Advancing means according to claim 15 wherein: each of said clamp assemblies includes a pair of elongated clamps extending along said path and on opposite edges of said web, said clamp assemblies being positioned to engage said edges when closed.

17. Advancing means according to claim 15 wherein: said cam includes a major portion of uniformly increasing radius; and said cam followers are positioned at diametrically opposite points on said cam.

18. A method for continuously advancing a web of sheet material through a machine having at least one work station for intermittently operating on said sheet material comprising the steps of: engaging said sheet with a first engaging element and feeding said sheet a given distance through said machine with a forward stroke of a first engaging element; then engaging said sheet with a second engaging element which is moving at the same velocity as said first engaging element near the end of its advancing stroke, and thereafter releasing said sheet by said first engaging element; then returning said first engaging element to the beginning of its stroke while advancing said sheet with said second engaging element a second given distance along said path; then re-engaging said sheet with a first engaging element which is moving at the same velocity as said second engaging element near the end of its advancing stroke, and thereafter releasing said sheet by said second engaging element; and moving said work station at the same velocity and direction as said sheet during the intervals that said work station is operating on said sheet.

19. A method according to claim 18 for continuously advancing a web of sheet material through a machine having at least one work station for intermittently operating on said sheet material comprising the steps of: successively performing the steps set forth in claim 18 a plurality of times.

20. A machine for working upon a continuous web of sheet material comprising: means for directing said web in a predetermined path; a work station positioned along said path; means for continuously advancing said web in a forward direction along said path past said work station, said advancing means including first and second feed elements, each of said feed elements being mounted for reciprocating movement along said path and each being adapted to intermittently engage and advance said web during the forward motion of the element; said work station being fixedly linked to one of said feed elements for reciprocating movement therewith, and drive means for alternately reciprocating said feed elements, said drive means including a mechanical linkage connected between said feed elements.

21. Apparatus comprising a supply of material in web form, a reciprocable work station for performing at least one operation on said web, at least one reciprocable gripper for grasping said web and advancing it past said work station, a single cam, and means connecting said single cam to both said work station and said gRipper to reciprocate said work station and gripper.