US2584622A

US2584622A - Process of and mechanism for fabricating filled capsules

Info

Publication number: US2584622A
Application number: US26384A
Authority: US
Inventors: Scherer Robert Pauli; Scherer John Otto
Original assignee: Catalent Pharma Solutions Inc
Current assignee: Catalent Pharma Solutions Inc
Priority date: 1948-05-11
Filing date: 1948-05-11
Publication date: 1952-02-05
Anticipated expiration: 1969-02-05

Description

Feb. 5, 1952 R. P. SCHERER ET AL PROCESS OF AND MECHANISM FOR FABRICATING FILLED CAPSULES 2 SHEETSSHEET 1 Filed May 11, 1948 641/225 ear/ W Feb. 5, 1952 R. P. SCHERER ETAL 2,584,622

PROCESS 01 AND MECHANISM FOR FABRICATING FILLED CAPSULES Filed May 11, 1948 2 SHEETS-SHEET 2 6A 49A 22A |8A |ek 22A M Z W k I '11 I I 20A 20A N ENTORS POBL-Rffi 0/5952 Swa /z 6PM Patented Feb. 5, 1952 PROCESS OF AND MECHANISM FOR FABRICATING FILLED CAPSULES Robert Pauli Scherer, Detroit, and John Otto Seller-er, Grrosse Eointe Park; Micln, assignors to R. P. Scherer Corporation, Detroit, Mich.-, a

corporation of Michigan Application May 11, 1948, Serial No. 26,384

8. Claims. {CL 181-9) This invention relates to improvements in a process of and mechanism for fabricating filled capsules. It relates particularly to the fabricating of the liquid filled gelatin capsules of commerce.

Heretofore such capsules have been fabricated in rotary die machines of the character disclosed in U. S. Patent 1,970,396 of August 14, 1934, to Robert P. Scherer, and also in reciprocating plate machines of the general character illustrated in Patent 2,294,633 of September 1, 1942, to the same inventor. r

- In the machine illustrated in the last named patent, a bag formed of two gelatin sheets and filled with liquid capsule content material is placed between two cooperating die plates. These two die plates are provided with complementary capsule forming cavities. Each cavity is surrounded by an elevated cutting ledge. The two plates are supported to be advanced toward each other against opposite faces of the liquid filled bag. The liquid content material within the bag is urged into the pockets formed between those complementary areas of the sheets which overlie the cavities and the sheets are sealed together along'a line surrounding each such pocket by the cooperating ledges of the die members thereby forming liquid filled capsules which capsules are severed from the sheets by the ledges of the die members. v I

.In"' the reciprocating plate machines which antedated the Patent No. 2,294,633, but which were'of the .same general character, a certain amount of the content material within the bag tended tocollectbetween portions of the sheets outside ofv the capsule forming areas surmounting thecavities. Such portions of the sheetsremaining after the capsules have been cut therefrom are called the net. Asthis content material is expensive, itwas common practice to salvage it fromflthe net. The apparatus of said Schere'r Patent 2,29%,633-was devised to more completely forcethe liquid content material on to the capsuleforming areas of the sheet surmountingthe cavities. and to minimize the collection of the content material within the net.

The instant application illustrates a flat reciprocating plate machine ofthe general character illustratedin Patent'2',294,633 supra and constitutes an improvement thereon. .The machine of thisapplication' is adapted to be set to advance suitable pressure pad members toward each other angiag'ainst the gelatin sheets until the resistance oflered by the'gelat'insheets reachesa predetermined value? 1 ween this resistance value is reached, further compression movement of the pressure pads is automatically stopped. The pads are then held fixed at such advanced positions against any possibility of retraction while the die plates are advanced therebeyond and toward each other to form, seal and sever the capsules from the sheets.

The movement of the pressure pads toward each other and against the gelatin sheets to press said sheets together until a predetermined resistance isreached urges all of the content material from between those portions of the sheets overlying the pressure pad members into the pocket areas overlying the capsule forming cavities of the die plates. wastage of content material in the net is therefore reduced to a minimum.

As the pressure pads are then positively held against retraction at such positions, while the die plates are advanced to seal the gelatin sheets togetherabout the capsule cavities and form the capsules and to sever the capsules from the net, those portions of the gelatin sheets disposed between the ledges of the die plates are held against extrusion into the area surrounding the capsule cavities between the pressure pads. Such portions of the gelatin sheets are extruded from between the ledges of the die plates and into'the wall structure which goes to form the capsule shell and therefore reinforces such shell and particularly the joint formed between the two halves of the shell. Y

The instant application is a continuation in part of abandoned application Serial No. 576,238, filed February 5, 1945. e

Other objects, advantages and meritorious features will more fully appear from the following description, appended claims and accompanying drawings:

Fig. l is a vertical sectional view through a pair of cooperating die members and associated mechanism embodying this invention.

Fig. 2 is a plan of'one of the die members shown in Fig. 1.

Fig. 3 is a fragmentary sectional view taken on the line 3-3 of Fig. 2, illustrating the cooperating action of the fence or frame members against the gelatin sheets.

Fig. 4 is a fragmentary sectional view taken on the same line as Fig. 3 showing the cooperative action of the pressure. pad plates against the gelatin sheets ahead of the die members.

Fig; 5 is a fragmentary sectional view taken on the same line as Fig. 3 showing the coopera- C tive action of the die members upon the gelatin sheets following compression of the sheets between the pressure pads.

Fig. 6 illustrates hydraulic operating mechanism for carrying out the process.

In Fig. 3 let I and i2 indicate two complementary gelatin or other suitable plastic sheets with liquid content material l4 therebetween and disposed between a pair of complementary spaced apart die plate, pressure pad, and fence assemblies. In the lower assembly a fence or frame 16 encircles a die plate 13 and a pressure pad 20 which pad superimposes the die plate. The

die plate is provided with capsule cavities 22. Each cavity 22 is surrounded by a ledge 24 which ledge projects above the face of the die plate. The pressure pad is provided with openings through which the ledges extend as shown in Figs. 1 and 2.

In a simple reciprocating plate machine the gelatin sheet If) may be spread over the lower fence, the lower die and the lower pressure pad. Upon the sheet is delivered the desired amount of content material to fill the number of capsules to be formed by the die member. The sheet sags down as shown and a second sheet I2 is then spread thereover.

An upper cooperating complementary assembly including a die plate l8a, a pressure pad 26a, and a fence 5a is provided. The upper die plate is provided with capsule cavities 22a complementary to the cavities 22 and surrounded by elevated cutting ledges 24a complementary to the ledges 24.

The two cooperating assemblies are disposed within a stationary framework 26. fence It is shown as supported by push rods 28. The push rods are slidable through a fixed frame section 32. Springs 30 encircle the rods and seat at their upper ends against the frame section 32 and seat at their lower ends against pistons 36 mounted on the rods to hold the rods down. The pistons are disposed within hydraulic cylinders 31 carried by a fixed frame piece 34.

The lower die plate I8 is supported by a push rod 38 which extends slidably throughthe frame section 32 and is held down by a spring 40 which spring seats at its upper end against frame section 32 and atits lower end against piston 42 mounted on the rod and slidable within hydraulic cylinder 43. v

The lower pressure pad is supported by push rods 44, cross piece 41 and struts 46 as shown in Fig. 6. Push rods 44 carry pistons 45 slidable within hydraulic'cylinders 41. Springs 46 are provided as shown in Fig. 6 to exert downward pressure onthe push rods. The

several push rods

28, 38 and 44 are hydraulically actuated counted the spring resistance in a determined sequence as hereinafter described.

The upper fence l6a, the upper die plate l8a and the upper pressure pad 20a, are supported in a similar manner for reciprocation being provided with operating push rods 28a, 38a and 4411, respectively The push rods are so hydraulically actuated that the fence members l6 and I So are first moved as shown in Fig. 3 to hold the sheets [3 and i2 therebetween. The pressure pads 20 and 20a are then moved to the positions shown in Fig. 4 to compress the sheets [0 and I2 therebetween. The die plates are then moved as shown in Fig. 5 cutting through the gelatin sheets and forming and severing the capsules therefrom all as shown in Fig. 5.

. When the pressure pads are moved toward each The lower other to the positions shown in Fig. 4, they move in response to hydraulic pressure operating mechanism hereinafter described to such a position that the resistance of the gelatin to further movement reaches a predetermined point. At this point the movement of the pressure pads toward each other automatically stops. This is accomplished as hereinafter described and it is this position that is shown in Fig. 4. At such position all of the liquid content of the material has been extruded from between those portions of the gelatin sheets 10 and I2 which overlie the pressure pads into the spaces between those portions of the sheets which overlie the die cavities.

When the die plates are moved together to seal the capsules about the content material and to sever'the capsules thus formed from the sheets of gelatin or other capsule shell material, those portions of the sheets which are positioned between the ledges of the die plates are held against extrusion into the space between the pressure pads because such space is filled with gelatin compressed between the pads. Such portions of the sheet material are therefore caused to flow toward the capsule cavities. Being extruded toward the capsule cavities such gelatin enters into the capsule shell and reinforces and strengthens the same particularly throughout the joint area formed between the two halves which make up the capsule shell. I

The hydraulic operating mechanism is illustrated schematically in Fig. 6. In this Fig. 6 three hydraulic pumps50, 52 and 54 are diagrammatically illustrated as driven from a source of power 56. These pumps are conventional. Pump 50 has a lead 58 which through upper and lower branches 60 extends to the cylinders 31 and 310 which actuate the pistons 36 and 36a and through the plungers 28 and 28a moves the fence members Sand "in. Pump 52 has an outlet 62 which through upper and lower branches 54 extends to cylinders 41 and 41a to actuate the pistons and 45a to advance the pressure pads 20 and 20a. Pump 54 has an outlet 66 which through upper and lower branches 68 extends to cylinders 43 and 43a to advance the pistons 42 and 42a to actuate the die plates l8 and 18a.

These pumps are similar in character and capacitated to deliver the required amounts of liquid. In the outlet of each pump is a 3-way valve 10. These valves are adapted to be actuated through control mechanism 12 so as to cause the pumps to deliver liquid to the cylinders or to cause them to deliver liquid to return outlets I4 which lead back to a source of liquid.

The

outlets

58 and 62 from the pumps and 52 which'supply liquid to the cylinders 31, 31a,-

41, and 4111 are provided with check valves 18. These check valves are provided in order that when the fence member 16 and 16a and the pressure pad members 20 and 20a are closed to the positions shown in Figs. 3 and 4 respectively, and the liquid pressure reaches a predetermined value due to resistance of the gelatin sheets to further compression, the relief valves 18 in the outlets from the pumps 50 and 52 will open and permit the bypassing of liquid back to the source. Upon the opening of the relief valves 18 with consequent flow of liquid therethrough and discontinuance of flow through the check valves 18, the'check valves will'close and will maintain the determined pressure which has been built up -in; th nes and he for m in fence 5. members. and the pressure. pad members at the positions. shown. in Fig. 4;

There is a similar relief. valve 80in the outlet 55, from the pump 54 but. this serves solely as a, relief valve for this pump outlet is not provided with a check valve inasmuch. as this is the pump that. actuates the die plates. The check valves; serve the purpose in the lines. which lead to the pressure pad cylinders and the. fence cylinders. of positively maintaining the pressure pads and. fence. members at; their advanced positionsv during the final advance of the die plates.

'Ilhe: single cylinders; 4.3 and 43a .whichv receive liquid to advance the pistons .42 and 42a to move the. .die plates are shown as having twice the area of one. of. the pair of cylinders 31 or 41 and the several pumps and cylinders are so capacitated that the fence members, pressure pad members, and die plate members, are advanced in unison but in the relative positions shown inFig. 1 of the drawing 50 that they come together successively as shown in Figs; 3, 4 and 5 to accomplish the desired results.

- What we claimis:

1... In apparatus for use in themanufacture of capsules, in. combination, .a. pair of cooperating die platesprovided .in their cooperating. faces with complementary elevated cutting ledges, a

pressure pad associated with one die plate having openings to receive the cutting ledges of the die plate therethrough, complementary frame members adapted to hold complementary capsule forming sheets together along a line surrounding an area filled with content material between the plates, mechanism operableto advance one die plate toward the cooperating die plate to bring their complementary cutting ledges together through capsule sheet material disposed therebetween, pressure sensitive mechanism operable to advance said pressure pad in advance of its associated die plate until the resistance of the capsule sheet material ofiered to said advance reaches a predetermined value, said last mentioned mechanism responsive to such resistance to stop the advance'of the pressure pad regard-v less of the distance advanced and positively hold the pressure pad at the point to which advanced,

said die plate advancing mechanism being operable to advance the die plate to bring the complementary ledges of the die plates together while said pressure pad is held at advanced position.

2. In apparatus for use in the manufacture of capsules, in combination, a pair of complementary die plates provided in their respective cooperating faces with complementary capsule forming cavities encircled by complementary ledges projecting above the faces of the die plates, complementary pressure pads superimposing the die plates and having openings through which the ledges are received, hydraulic operating mechanism coupled with said pressure pads and die plates operable to advance them relatively toward each other to compress capsule forming sheets between the pressure pads prior to compression of said sheets between the die plate ledges, said hydraulic operating mechanism including means responsive to a determined resistance oifered by the capsule forming sheets to advance of the pressure pads to stop said advance regardless of the distance advanced and hold the pressure pads positively at the point to which advanced and means operable upon discontinuance of advance of the pressure. pads to advance the die plates toward each other to bring their ledges together beyondthe pressure pads.

6v 53,; Inapparatusror use in; the ma ufacture or capsules. in combination, a pair of cooperating die plates, exhibiting in their respective operating faces complementarycapsule forming cavities ens-- circled by complementary elevated ledges, a pressure pad superposing each die plateand having; openings proportioned to receive the. die plate ledges ther., ethrough,v complementary frame members adapted to hold complementary capsule formingsheets together along a linesurrounding an area filled withcontent material between the pads, pressure pad advancing means responsive to. predetermined. resistance offered by said sheetst.0..- advance:- movement of the pads relatively. to-.-

wardeach. other for discontinuingv such movement and positively holding. the pads at such ad.- vanced position, and means for moving said die plates ,relatively. toward each other to project theirledges; beyond the pressure pads and through the sheets: while said pads are held. at theadvanced. position.

4.. Ina. process of forming; filled capsules which embodies holding complementary-portions of two sheets of plastic capsule forming material together'along a line enclosing liquid capsule content material formingabag filled with said liquid content: material, advancing complementary die plates and complementary pressure pads relative.- 1y toward each other and toward opposite sides of said bag, the complementary faces of said die plates provided with complementary capsule forming cavities encircled by complementary elevated sealing and cutting ledges and the complementary pressure pads provided with complementary openings therethrough received over said ledges of the die plates, and advancing said complementary die plates and pressure pads in such a manner that the pressure pads are advanced ahead of the die plates and urge the sheets together therebetween in advance of the die plates thereby urging the content material between the sheets'into pockets formed between complementary areas of the sheets overlying the cavities in the die plates, the improvement which comprises the steps of continuing the advance of the pressure pads until a predetermined resistance to such advance ofiered by the sheets is encountered and stopping the advance of the pressure pads at that position regardless of the distance the pads have advanced, and holding the pressure pads at the positions at which they were stopped while continuing to advance the die plates to seal the sheets together about the capsule cavities to thereby form sealed capsules and sever them from the sheets.

5. In a process of forming filled capsules which embodies the steps of holding complementary portions of two sheets of plastic capsule forming material together along a line enclosing liquid capsule content material forming a bag filled with said liquid content material, and advancing against opposite walls of the filled bag complementary pressure pads and die plates for forming and severing filled capsules, the improvement which comprises the steps of moving the pressure pads toward each other in advance of the die plates until a predetermined resistance to such movement is encountered, stopping the movement of the pads at that point and positively holding them in such advanced position while continuing to advance the die plates toward each other to thereby form and sever the capsules.

6. In a process of forming filled capsules which embodies the steps of holding complementary portions of two sheets of plastic capsule forming material together along a line enclosing liquid capsule content material forming a bag filled with said'liquid content material, and advancing against opposite walls of the filled bag complementary pressure pads and die plates for forming and severing filled capsules, the improvement which comprises the steps of moving the complementary pressure pads and die plates toward each other with the pressure pads in advance of the die -plates until a predetermined resistance to the m'ovement of the pressure pads is encountered, stopping the movement of the pads at that point; and positively holding the pads in such advanced position while continuing to advance the dieplates toward each other to thereby form and sever-the capsules.

7. Apparatus for making capsules from superimposed sheet material with filler material disposedtherebetween comprising complementary die plates and pressure pads movable respectively toward one another, means for moving the pads in advance of the die plates until a predetermined resistance to movement is encountered, means for stopping such movement of the pads at that die plates while the pads are held immobile to thereby form and sever the caspules.

8. Apparatus for making capsules from super-' imposed sheet material with filler material disposed therebetween comprising complementary -die plates and pressure pads movable respectively for disconnecting from the pads their moving REFERENCES CITED The following references are of record in the file oi this patent:

UNITED STATES PATENTS Number Name Date 1,970,396 Scherer Aug. 14, 1934 2,172,546 Riel Sept. 12, 1939 12,294,633 Scherer Sept. 1, 1942 Gary, Jr. Apr. 15, 1947