US2288327A - Apparatus for forming and filling capsules - Google Patents

Description

June 30, 1942. R. P. SCHERER APPARATUS FOR FORMING AND FILLING CAPSULES 3 Sheets-11261. 1

Original Filed Oct. 8, 1935 INVENTOR.

Pobert P 25c he rer ATTORNEYS,

lllillh 4 will 3 Shefs-Sheet "2 June 30, 1942. R. P. SCHERER APPARATUS FOR FORMING AND FILLING CAPSULES Original Filed Oct 8, 1935 June 30, 1942. R. P. SCHERER APPARATUS FOR FORMING AND FILLING CAPSULES Original Filed Oct. a, 1935 3 Sheets-Sheet s I INVENTOR- fiobert 7? 5c herer ATTORNEYS.

Patented June 30, 1942 UNITED. STATES PATENT OFFICE APPARATUS FOR FORMING AND FILLING CAPSULES Robert P. Scherer, Detroit, Mich.

Application October a, 1935, Serial No. 44,011

Renewed September 1, 1939 v 15 Claims.

embodiment, a pair of die rolls over which bands or strips of capsule forming material such as gelatin are fedand a feeder head adapted to feed capsule content material onto selected portions of the bands which selected portions are shaped under the pressure of the content material to form the capsules. By this means capsules are simultaneously formed and filled with accurately measured dosages of content material.

An important feature, in mechanism of this character, is the provision of means to prevent leakage or'waste of the capsule content material and to exclude air from entering the capsules during the forming and filling operation. More particularly, thecapsule forming bands are so held between the feeder head and the die rolls during the forming and filling of the capsules that leakage of the capsule content material. is prevented, during the forming, filling and sealing of the capsules. Furthermore, provision is made to exclude air from the capsules.

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

Figure 1 is a side elevation of apparatus embodying my invention,

Fig. 2 is a front elevation of the apparatus illustrated in Fig. i,

Fig. 3 is an enlarged vertical sectional view illustrating a portion of the driving mechanism,

Fig. 4 is a sectional view showing a preferred form of the capsule forming and filling mechamsm,

Fig. 5 is an elevation of a fragment of the die roll shown in Fig. 4,

Fig. 6 is a detail of a modified form of die roli construction, and

Fig. 'l' is a sectional view through a modified form of die roll construction including the detail of Fig. 6.

My improved apparatus is designedto rapidly form and fill capsules as a continuous process with accurately measured dosages of any desired fluid content and without waste of the content material.

5 tween a pair of die rolls.

Molten gelatin is fed from a suitable source of supply to apparatus designed to form two bands or strips of gelatin. These bands are advanced 'along converging paths into juxtaposition be- Accurately measured dosages of fluid content are discharged onto correspondingly spaced apart selected areas of each band. The pressure of delivery of the fluid dosages deforms said selected areas of the bands 10 forming hollow hemispheres within which the dosages are received. The two bands are then brought together with complementary filled cavities in registration and sealed about the content material forming filled capsules. The functioning is such that during delivery and formation of the capsule, air is excluded therefrom and there is practically no waste of the fluid content.

In the construction shown there is a vat Hi wherein molten gelatin may be maintained at the desired temperature by heating means not here illustrated. The gelatin is delivered therefrom in a controlled stream onto the periphery of a drum !2. This drum is driven by a motor 14.

The gelatin forms a film or band l5 on the periphery of the drum. This band is taken off the drum and passes through a train of rolls It, I8, 20 and 22, which rolls may be driven from gear 24 carried on shaft 26 as shown in Fig. l.

30 Shaft 25 is provided with a gear 28 which,

through pinion 3!], drives shaft 32 to drive other parts of the mechanism as hereinafter described. Shaft 26 also through Worm gear i3 and Worm gear i l drives drum i2 mounted on shaft ii.

35 The rolls i6 and iii are hollow and oil is fed outwardly through their for-aminous peripheries and through absorbent peripheral facing thereon so that oil is delivered to Tooth surfaces of the gelatin band.

As shown in Fig. 2 two gelatin bands are formed and oiled as described. These two hands pass over guides 42 and elevator rolls it arranged at the top of the machine and are advanced along converging aths upon opposite sides of a feeder head 46 between die rolls 48 50 (see Figs. 2 and 4). This driving mechanism is shown more clearly in Fig. 3.

Gear 4!) drives shaft 50 through pinion 5t and in Fig. 1 this shaft 50 is directly in the rear of shaft 32. This shaft 50 drives the die rolls 48 5 through gears 54, 56, and 58. Each die roll shaft drives the other. The two die rolls are counterparts and one operates upon one band and the other upon the other band. Capsules are formed and filled as the gelatin bands I5 pass over the feeder head and between the vdie rolls and the juxtaposed bands pass downwardly as shown in Figs. 2 and 4 as a single double band ll. Stripper rolls 62 rotating counter to the direction of travel of the band ill strip the filler capsules l9 therefrom. These stripper rolls are so driven that one rotates at a greater rate of speed than the other to' facilitate stripping of the capsules from the band. These capsules fall upon collec- .tor delivery chutes 64 for discharge into a suitable receptacle not shown. The double band I? with the filled capsules now removed then passes to a suitable collector not shown for salvage of the gelatin.

'To assist in drawing the juxtaposed gelatin bands there is provided a pair of cooperating drag rolls 66. The stripper rolls 62 are driven from shaft 50 by gear and pinion 68 and 10 respectively. The drag rolls 66 are driven from the same shaft by gear and pinion l2 and 14 respectively. Note Fig. 3.

The feeder head indicated generally in Fig. 2 as 46 is shown in greater detail in Fig. 4. It comprises a casing or body having complementary arcuate faces which substantially conform to the curvature of the die rolls 48 as shown in such Fig. 4.

This feeder head is universally supported so as to position itself upon the gelatin bands passing over the die rolls so that the bands are held firmly against the rolls and against the arcuate faces of the head by the weight of the head. Pins 16 carried by brackets 18 supported by the framework of the machine afford a limit to the floating movement of the head but permit the head to float freely within its required limits.

The head is adapted to position itself rockably, tiltably, and vertically, that is universally, with respect to the bands. This insures that the arcuate faces of the feeder head will closely engage and snugly hold each band to its roll notwithstanding minor variations in thickness of the bands as regards each band and also with respect to each other. Minor variation in band thicknesses are difiicult to eliminate in production. In order to prevent leakage of capsule filling material it is necessary that each band be held closely against the arcuate face of the feeder head by the ledge Q0 surrounding those selected portions of the band which are to be deformed and filled and this construction subserves such end.

It is furthermore necessary that air be excluded from, entering the capsules during the filling and forming thereof, otherwise undesirable air bubbles will appear in the capsule content material. Through this free flotation of the feeder head the minor variations in thickness of the bands which might cause the feeder head to tilt and permit air to enter are accommodated for and a tight seal maintained.

The oil film which has been spread upon the two surfaces of each band facilitates free travel or each band without sticking and serves an additional and meritorious purpose in that sufficient excess of oil is fed upon the inner face of each band so as to form an oil seal adjacent to the arcuate face of the feeder head and sealing the joint thereagainst so as to prevent the entrance of air at such point. Any excess of oil 60 is provided with a gear 58 and one gear 58 is scraped off at this point damming up between the feeder head and the travelling band as at 19 in Fig. 4. Any small defect or irregularity in the gelatin bands will be filled from this excess of oil rather than with air as the bands are advanced into juxtaposition and air entrance is prevented.

The fluid medicament or the like-and wherever the term fluid is employed it is intended to include any suitable material which will fiow such as a paste, jelly, liquid, etc.,with which the capsules are to be filled is contained within a supply tank 80. This tank contains a multiple pump driven from shaft 8! in synchronism with the functioning of the machine that forms the capsules so that at the proper intervals the fluid.

is impelled through conduits 8 2, which conduits are provided in such number as desired depending upon the number of outlets through which fluid is impelled from the feeder head onto the bands. The feeder head is cored out providing a passageway which leads to outlets 84 through the arcuate faces of the head adjacent its tip.

Through these outlets the fluid. discharges onto the adjacent surfaces of the gelatin bands as they pass thereover.

These conduits 82 are so shaped and formed and connected with the feeder head as not to exert any restraint upon its desired self-positioning free flotation so that the feeder head rests with its own weight upon the'gelatin bands and accommodates itself thereto naturally without appreciable restraint.

The feeder head may be maintained at a desired temperature through the employment of a suitable heating element such as 86 to heat the gelatin bands to effect proper sealing of capsules.

The die rolls, which are substantial counterparts, are hollow and each is provided with a plurality of die recesses or cavities 88. A ledge or flange 90, slightly bevelled, encircles each cavity. This flange snugly impinges the gelatin band urging the same against the arcuate face of the feeder head. When the die rolls come together these flanges come into contact sealing the two halves of the capsule together and severeing the gelatin band around the formed capsule thereby freeing the capsule for subsequent stripping from the band by the stripper rolls 62.

Within each die recess there is a plunger 92 which reciprocates by gravity. Each die roll is provided with a plurality of rows of die recesses 88 which rows extend lengthwise across the roll, therecesses being staggered in successive rows. The several plungers in a row are connected by a rod or link 94 whereby, should one plunger tend to stick in its recess, the weight of all of the remaining plungers will act to cause them to move in unison to release. This rod also prevents any one plunger from falling out. It is shown in detail in Fig. 6.

It is necessary that the die rolls be provided with limited clearances between successive capsule cavities to permit flow of the gelatin thereinto during sealing and severing of the filled capsules. It is desirable that these clearances be small so that each band will present the minimum extent of unsupported area intermediate successive capsule cavities. Should the band fall appreciably away from the arcuate face of the feeder head opposite a capsule content discharge aperture leakage of such content material might result. The present construction is designed to hold the band closely against the feederv head between successive die cavities in the roll and to prevent the band falling away from the feeder head.

In Fig. 4 this is accomplished by providing a band or plateau SI of narrow width lengthwise of the roll'between each successive pair of recesses 00. This band is of such a length circumferentially of the roll as to leave only a limited clearance 93 between the ends of the band and the flanges 90 and over which the band extends unsupported from the roll. This unsupported length of band is thereby so reduced at the critical point opposite the content discharge aperture 84 of the feeder head that the band follows the contour of the arcuate face of the feeder head and leakage of the filling material is prevented as its small unsupported length travels over the discharge orifice 84. In theconstruction of Figs. 4 and 5 the roll is relieved except for the ridges 90 and bands 9|.

Fig. 5 illustrates a fragment of the surface of the roll shown in Fig. 4.

In Fig. 7 the die cavities are located close together. This close arrangement is obtained by providing plungers 95 of the shape shown.v

The inner ends of the plungers are of reduced diameter as compared with the heads of the plungers. These reduced inner ends are tapered as illustrated. Due to this construction the plungcrs are arranged closely together and the unsupported extent of gelatin hand between successive die cavities is of limited extent.

In the operation of the machine the gelatin bands are speeded up slightly by the elevator rolls 44 driven through mechanism not here shown but from the driving mechanism illustrated, so that the bands are fed with only a small amount of tension or stretching to the die rolls thereby reducing the amount of pressure necessary to be exerted by the filling fluid upon the bands to deform the same to form the capsule cavities therein and insuring sufficient band stock of the proper tension to permit the band to follow closely the contour of the feeder head face. Inasmuch as the elevator rolls 44 rotate slightly faster than the casting drum the gelatin band is withdrawn from the drum in a slightly stretched or tensioned state. It is then fed to the die rolls with only a small or minimum amount of tension but relativel uniformly.

As each die recess 80 of the roll comes into position opposite a discharge outlet 84 of the feeder head the mechanism is so synchronized in its functioning that filling fluid is impelled onto the band deforming the same under the pressure of the fluid delivered and stretching this selected area of the band into the die recess as shown. The fluid fills the cavity thus formed against the resistance of the stretched gelatin and the flange 90 holds the band snugly against the arcuate face of the feeder head around said deformed area so that leakage of the fluid content therefrom or admission of air thereto is prevented.

The bands travel continuously and each band with its filled cavities moves along into convergence with the cooperating band which islikewise provided with corresponding cavities similarly filled. The two bands come together between the die rolls with the filled cavities brought into registration. The bands are pressed together around the filled cavities by the flanges 90 as shown forming a unitary capsule around the fluid content of each mating pair of cavities. The flanges also cut through the band rethe formation of the capsules.

are mounted upon shafts which may be driven die roll passes downwardly and thereby assist in' Brushes 06 are expelling the filled capsules. provided to engage the outer periphery of the die rolls removing any stray particles and keeping a uniform oil film on all portions of the surface. These brushes rotate counter to the rotation of the rolls to brush the oil film onto the hi h edges of the flanges from which it has been wiped in These brushes by belt I00 from drivers I02 on shafts 0.0.

What I claim:

1. In apparatus for making and filling capsules, a pair of die rolls provided with capsule forming cavities, means for feeding a pair of capsule forming bands over said rolls into juxtaposition between the rolls including a feeder head arranged between said bands and supported to float universally thereupon holding each band to its roll adjacent to the point of juxtaposition of the bands between the rolls.

-2. The invention as defined in claim 1 characterized in the provision of mechanism adapted to 'minimize tension of the bands for travel between ledge and a peripheral depression lying outward 1y adjacent said ledge, said roll so formed that the depressed area between successive cavities circumferentially of the roll is so reduced in extent that the band as it passes over the roll is not permitted to fall appreciably away from the feeder head circumferentially of the roll intermediate successive cavities in the roll.

4. Apparatus for making and filling capsules comprising a pair of die rolls, means for feeding capsule forming hands over said rolls into juxtaposition therebetween including a feeder head supported between said bands to bear thereupon to hold each band to its roll as it passes thereover into juxtaposition with the cooperating band, each roll provided with a plurality of spaced apart capsule forming cavities each surrounded by a narrow peripheral ledge and a peripheral depression lying outwardly adjacent to said ledge, and an elevated portion arranged within said depression between successive cavities circumferentially of the roll spaced from the ledges surrounding the cavities.

5. Apparatus for making and filling capsules comprisinga pair of die rolls, means for feeding capsule forming bands over said rolls into juxtaposition therebetween including a feeder head disposed between said bands to bear thereupon to hold each band to its roll as it passes thereover into juxtaposition with the cooperating band, each roll provided with a plurality of correspondingly spaced apart capsule forming cavities each surrounded by a narrow peripheral ledge and a peripheral depression lying outwardly adjacent to the ledge, successive'cavities being disposed in such close proximity that each band as it extends over its roll into juxtaposition with the cooperating band is held between successive cavities toward the feeder head without appreciable falling away therefrom.

6. Apparatus for making and filling capsules comprising means for feeding a pair of plastic capsule forming bands along converging paths into juxtaposition including a pair of die rolls engaging the bands and adapted to bring them into juxtaposition, said rolls provided with a plurality of recesses correspondingly positioned axially 1 across the rolls and circumferentially therearound, a feeder head positioned between said bands upon the rolls provided with arcuate faces correspondingto the curvature of the rolls, said feeder head supported to float universally upon said bands for rockable, tiltable, and vertical movement upon said bands holding them against the rolls, and means for feeding fluid filling substance through the arcuate faces of the feeder head under pressure upon selected areas of each band opposite the recesses in the rolls deforming said areas by stretching the material of the band into the recesses of the roll forming cavities within the band to receive the fluid filling substance, said means being so connected with the feeder head as not to exert any appreciable restraint upon its free floating movement.

7. Apparatus for forming and filling capsules comprising a pair-of cooperating rotatable die rolls each provided with a plurality of die recesses arranged in spaced apart relationship lengthwise across the roll, means for advancing a pair of gelatin bands into juxtaposition between said rolls, means adapted to distribute oil over said hands before engaging said rolls, and means adapted to wipe the oil film left on the roll by the band evenly over each roll.

8. Apparatus for forming and filling capsules comprising a pair of rotatable die rolls, means for advancing a pair of gelatin bands into juxtaposition between the rolls including a feeder head operable to urge each band against the periphery of its r011 just prior to the juxtapositioning of the bands between the rolls, said head supported for free rockable and tiltable flotation upon the rolls adjacentthe point of juxtaposition of the bands between the rolls, each roll provided with a plurality of spaced apart die recesses arranged in circumferentially spaced apart rows extending lengthwise of the roll, means for oiling the two surfaces of each band, means for distributingthe oil film left by the band on the roll evenly over the surface of the roll, and means for reducing the tension in each band prior to its introduction to its roll.

9. In apparatus for forming and filling capsules, a pair of rotatable die rolls, means for feeding two bands of capsule forming material into convergence between said rolls including a feeder head disposed between the band to hold each band to its roll, means for feeding an excess of oil onto inner surface of each band, and means arranged to scrape oil from the inner face of each band to collect and seal the band against the feeder head against admission of air therebetween.

10, In apparatus for forming and filling capsules, a rotatably driven casting drum, means for delivering molten capsule forming material thereupon, a rotatably driven die roll, means for advancing a capsule forming band from the drum to the die roll including a roller engaging said band between the drum and the die roll and driven at a rate of surface speed greater than the surface speed of the casting drum to withdraw the band under tension from the drum and advance the band under uniform but small tension to the die roll.

11. In apparatus for forming and filling capsules, a rotatably driven casting drum, means for delivering molten capsule forming material thereupon, die means operable to act upon a band of capsule forming material withdrawn from the drum, means for advancing a capsule forming band from the drum to the die means including mechanism frictionally engaging said band between the drum and the die means acting upon the band to impose a tension of withdrawal upon the band from the drum and to advance the band under reduced tension to the die means.

12. Apparatus-for forming and filling capsules comprising, in combination, a pair of cooperating die rolls, said rolls provided with correspondingly spaced apart die cavities, each cavity encircled by a narrow ledge, each roll having its die face between said cavities depressed below the level of said ledges, means for feeding a pair of capsule forming sheets into juxtaposition between said rolls, means for delivering capsule content material onto the adjacent faces of said sheets opposite the die cavities, each roll provided with a plurality of spaced apart sheet supporting elevations projecting above the surface of its depressed area, said elevations being located between the cavities and spaced from their encircling ledges a distance sufficient to permit flow of sheet material under pressure from the ledges into said space, said space being insufficient to permit a sheet supported upon said ledges from sagging appreciably thereinto.

13. Apparatus for forming and filling capsules comprising, in combination, a pair of cooperating die rolls, said rolls provided with correspondingly spaced apart die cavities, each cavity encircled by a narrow ledge, each roll having its die face between said cavities depressed below the level of said ledges, means for feeding a pair of capsule forming sheets into juxtaposition between said rolls, means for delivering capsule content material onto the adjacent faces of said sheets opposite the die cavities, said die cavities in the face of the roll being so closely spaced that their encircling ledges are spaced apart a distance insufficient to permit a sheet resting thereupon sagging appreciably into the depressed area therebetween.

14. Apparatus for forming and filling capsules comprising, in combination, a pair of cooperating die members each provided with a plurality of correspondingly spaced apart die cavities, a narrow ledge encircling each cavity, each die member having its face depressed between the ledges encircling said cavities, each die member having elevated portions including said ledges and islands spaced therebetween rising above its depressed area and adapted to support a sheet of capsule forming material, said elevated portions spaced apart a distance insufiicient to per-- mit a capsule forming sheet supported thereupon sagging appreciably into the depressed area therebetween.

15. Capsule forming apparatus comprising, in combination, die mechanism operable to act upon a pair of juxtaposed bands of capsule forming material to form capsules therefrom, drum mechanism rotatably driven and acting upon said bands urging the bands toward said die mechanism, rotatably driven roller means interposed in the line of advance of the bands from the drum mechanism tothe die mechanism acting upon each band to withdraw the band from the drum and to advance the band toward the die mechanism, said roller means being driven at a rate of surface speed of rotation greater than the rate of surface speed of rotation of the drum members.

ROBERT P. SCHERER.

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