Powder filling means

Abstract

A machine for filling powder into capsules. A first turret carries a plurality of filling needles. A second turret, in overlapping edge meshing relation to the first turret, carries an annular diaphragm trough containing loose powder. A third turret, also in overlapping edge meshing relation to the first turret, carries the capsule bodies. The filling needles are mounted in radially movable slides, which are cammed to synchronize with the movement of the bodies before and after the central point of overlapping edge meshing tangency so as to permit high speed continuous synchronized movement of all three turrets.

Description

This invention relates to powder filling apparatus, and more particularly, to means for filling capsules with powders in the pharmaceutical industry.

The capsules are filled by filling needles which are piston type devices. One of the problems is to get a full charge in the filling needle, and another problem is to synchronize the needles with the capsule bodies with continuous non-intermittent motion, so that high speed can be achieved. The powder may be non-free flowing, like talcum powder, or free flowing powders.

The Applicant has solved the first problem by mounting the filling needles on a first turret and mounting the loose powder reservoir on a second turret. The reservoir comprises an annular flexible diaphragm or trough, which is mounted on the second turret in overlapping edge meshing relation to the needles mounted on the first turret. A plurality of rams are mounted under the diaphragm in register with the needles. As the needles pass over the reservoir, which is moving at the same speed as the needles, the rams operate to present a standing wave of powder to the filling needles. The rams and needles are cammed in synchronism.

The second problem of high speed filling of the capsules is solved by the present invention by mounting the capsule bodies on a third turret in overlapping tangential relation to the needles mounted on the first turret. To obtain high speed continuous filling, it is necessary that the needles and the capsules be in registration for a pre-determined distance before and after the point of central overlapping tangency of the two turrets. In order to do this, the needles are mounted on radial slides on the first turret and the slides are cammed so that the needles approximately follow the body path on the second turret for a pre-determined distance before and after the point of central tangency.

Accordingly, a principal object of the invention is to provide new and improved powder filling means.

Another object of the invention is to provide new and improved means for filling capsules with high speed continuous motion.

Another object of the invention is to provide new and improved means for filling capsules with high speed continuous motion of the order of 1600/minute.

Another object of the invention is to provide new and improved means for filling powder into capsules comprising a first turret rotatably mounted and adapted to carry capsule bodies along its periphery, a second turret rotatably mounted and adapted to carry powder filler needles spaced along its periphery, said first and second turrets being arranged to rotate continuously in a generally overlapping tangential relation, a plurality of radial slides mounted on said second needle carrying turret, one of said needles being mounted on each of said slides, means to cam said slides radially to substantially follow the circular motion of said capsule bodies mounted on said first turret for a predetermined distance before and after the central point of tangency of the first and second turrets, whereby said needles are in position to fill said capsule bodies for a predetermined distance before and after a central point of tangency during continuous motion of said turrets.

Another object of the invention is to provide new and improved means for filling powder into capsules comprising a plurality of powder pick-up needles, each having a reciprocatable sleeve and a reciprocatable piston, a reservoir adapted to contain powder, said reservoir comprising a flexible diaphragm, means to movably position said pick-up needles over said flexible diaphragm containing said powder, ram means located under said flexible diaphragm and means to operate said ram means to push powder to the said needles.

Another object of the invention is to provide new and improved means for filling powder into capsules, having a first turret rotatably mounted and adapted to carry bodies along its periphery, a second turret rotatably mounted and carrying work members spaced along its periphery, said first and second turrets being arranged in a generally tangential relation, a plurality of radial slides mounted on said second carrying turret, each of said work members being mounted on one of said slides, means to cam said slides to substantially follow the circular motion of said bodies mounted on the first turret for a predetermined distance before and after the central point of tangency of the first and second turrets, whereby said work members are in position to act on said bodies for a predetermined distance before and after a central point of tangency with continuous motion of said turrets.

These and other objects of the invention will be apparent from the following specification and drawings, of which:

FIGS. 1 and 1A are diagrams illustrating the operation of the invention.

FIG. 2 is a side view, partially in section, of a filling needle assembly.

FIG. 2A is an end view of FIG. 2.

FIG. 3 is a plan view of an embodiment of the invention.

FIG. 4 is an elevation view, partially in section, illustrating the powder filling turret.

FIG. 5 is a plan view, partially in section, illustrating the filling of the capsules by the filling needle.

FIG. 6 is a partial developed side view of the cam for the filling needles.

FIG. 7 is a detail view of the cam adjustment for the filling needles illustrating means to adjust the amount of the charge taken by the filling needle.

FIGS. 8 and 8A are diagrams illustrating the capsule filling operation.

FIG. 9 is a diagram illustrating the mathematical relation of the Registration Error.

FIG. 1 illustrates a diagram illustrative of the operation of the invention. There are two turrets, one for filling needles and one for the capsules.

The capsules are mounted about the periphery of the turret 1 at points 1, 2, 3, 4, 5, 6, etc., so that when the turret 1 rotates, the locus of travel of the capsules would be along the line C.

The filling needles are mounted on the other turret 9. However, in order to secure registration of the needles and the capsules, it is necessary for the needles to also travel along close to the line C before and after the point of central tangency. In order to accomplish this, the needles are mounted on slides, as will be described. The slides are cammed so that the needles are retracted the distances D1, D2, D3, etc.

Referring to the point 6, if the needle is retracted by the slide the distance D3, then there will be perfect registration at the point 6. Referring to point 5, if the needle is retracted the distance D1, there will be a slight error E1 of registration. At point 4, the error will be E2 and point 3, the error would be E3, and at point 2 there will again be perfect registration. The same effect occurs on the other side of the point 6 all the way down to the points 7 and 7a, and beyond. If the slides are properly cammed, then the errors of registration occurring between the points 2a and 7a are within the allowable tolerance so that the needles can be filling the capsules as the capsules move from point 2a to point 7a. The diagram in FIG. 1 is somewhat exaggerated since the turrets in actual practice are much larger.

Referring to FIG. 1A, the size relationship of the capsule body B' and the powder charge P is illustrated. The charge P is made smaller than the capsule body so that there will be sufficient space for the air to escape when the charge is inserted in the capsule body. This difference in size also provides sufficient tolerance to accommodate the registration errors E1, E2, etc.

FIG. 8 and 8A illustrate a side view of the powder charge P and the body B' of the capsule. Note that when the charge is inserted, it extends above the top of body B'. The purpose of this is so that when the cap C is placed on the body B', then the powder P will substantially fill the capsule.

FIG. 9 shows a diagram illustrating the mathematical relationship of the error. The error E.sub.1 = D.sub.1 sin a.sub.1, where a.sub.1 is the angle of the turret from the center line L connecting the centers of the turrets. Similarly,

E.sub.2 = D.sub.2 sin a.sub.2

D.sub.1 and D.sub.2 are the displacements between the turret edges along a line parallel to line L and through the reference point on the capsule turret 1.

Therefore, the general formula would be:

E = D sin a

It is noted that where D = 0 at the upper and lower points, there is perfect registration; and also at the point 6, where sin a = 0, there is perfect registration. On either side of point 6, the line of travel of the fill needles, illustrated by the dotted line X, is symmetrical about point 6 relative to the line of travel of the capsules.

FIG. 2 shows a side view of a slide mounted needle and FIG. 2A shows an end view. The needle assembly is mounted with a slide 10, which is slidably mounted in turret 9. The needle comprises a piston 11 having a porous tip 11b and a sleeve 12. The piston is mounted on the block 11', the sleeve is mounted on block 12', and both blocks are adapted to slide up and down in gibs 13. The block 11' has a cam follower 11a and the block 12' has a cam follower 12a. Both of these followers ride in cam grooves 14a and 14b which are cut in fixed cam 14. Cam 14 has another groove 14c and the slide 10 has a cam follower 10a, which is adapted to ride in the groove 14c. The cam 14 is fixed in position and the groove 14c is cut so that the needles substantially follow the line C illustrated in FIG. 1. The grooves 14a and 14b are cut to cause the needles to pick up and discharge the powder at the proper times during the cycle, as will be described.

Referring to FIG. 3, there are shown three turrets: the needle turret 9 with a plurality of slides 10, the capsule turret 1 in overlapping tangential relation to the needle turret, and the powder supplying turret 20 in overlapping tangential relation to the needle turret 9. The turrets are driven in synchronism by means of the driven shaft 21 and worm gear 22, which drives the gear 23 connected to the filling needle turret. The turret 20 is driven by means of the worm gear 24, which is connected to gear 25, which is mounted on the powder supply turret 20. The turret 1 is driven in synchronism by means of the timing chain 26, which is mounted on the sprocket 27, which in turn is mounted on the shaft 21. The timing chain 26 drives a similar worm gear arrangement on the turret 1, which is not shown.

Referring, also, to FIG. 4, the powder supply turret 20 is rotatably mounted in the frame F by means of shaft 29 mounted in bearings 30, 31. Around the outer periphery of the turret 20 is mounted a flexible diaphragm reservoir, or trough 32, which is annular and extends in a complete circle around the periphery of the turret 20. In the upper rear of FIG. 4 is shown a reservoir 33, which is adapted to fill the trough by gravity as the trough passes under the filler bin 34. A suitable leveling blade is preferably provided to level off the powder P in the trough.

There are a plurality of plungers 35 mounted around the periphery of the turret 20, the number of plungers being equal in number to the number of needles on the turret 9, and the plungers are in registration with the needles as the needles come into filling position, illustrated in FIG. 4. As this happens, the plungers ride up on cam 40 so that the plungers 35 rise up, as shown by the dotted lines, forcing the diaphragm up into the position shown by the dotted lines, and presenting the powder to suction on each needle and filling by vacuum, as described in copending Application, Ser. No. 626,083, filed Mar. 27, 1967, for METHOD AND APPARATUS FOR MEASURING AND DISPENSING PREDETERMINED EQUAL AMOUNTS OF POWDERED MATERIAL, now U.S. Pat. No. 3,656,518. The vacuum is supplied from valve 42.

The needle turret 9 then rotates counter clockwise as shown in FIG. 3 and the slides 10 are operated by means of the cam track 14c, as previously described, so that the needles are in substantial registration with the capsules on the turret 1.

More specifically, the line of travel of the needles is shown by the dotted lines 12a and the line of travel of the capsule bodies 15 is illustrated by the dotted line 15a. As illustrated in FIG. 3, the slides are retracted to follow the circular path 15a within the area before and after the point of central overlapping tangency, so that the needles are in registration with the bodies 15 for a long enough time to discharge each filling needle into a capsule body by gentle cam action not instantaneous at one point.

The retracting movement of the slides is provided by means of the annular cam 14, which is fixedly mounted on the base B of the machine by means of legs 40, 41. Referring, also, to FIG. 2, the slide motion is provided by means of cam follower 10a riding in the groove 14c of the peripheral cam 14.

The up and down motion of the needle piston is provided by means of the groove 14a and the up and down motion of the sleeve of the needle is provided by means of the groove 14b. These grooves are illustrated in FIG. 6, which is a developed view of the cam 14, and the grooves are cut so that the piston 11 is retracted while the needle is being filled and the piston is pushed down when it is desired to eject the powder charge into the bodies 15 on the turret 1.

After the charge has been ejected, an air blast is fed to the sleeve 12 to clean it out. During the time that the filling needle is picking up and holding the powder, vacuum is applied to the tube 11b. Tube 10b is open to atmospheric pressure. The alternate air and vacuum is supplied by means of the valve 42 mounted on the turret 9. The valve 42 is constructed so that vacuum is supplied during the powder filling cycle until just before the powder is ejected from the needles and air is applied thereafter to clean the filter on the inner needle and sever the powder charge cleanly from the filter.

FIG. 5 shows how the filling needle assembly nests with the turret 3, which carries the capsule bodies. The turret 1 itself is conventional. The lower portion of the body 15 is carried on a vacuum holder 16 which is mounted on a plunger 17. The upper part of the capsule cap 18 is mounted on a vacuum holder 19 which is mounted on a plunger 20.

The filling needle assembly is shown in filling position with the plungers 17 and 18 of capsule body turret 23 retracted by conventional cam mechanism. Details of the body turret 9 may be as disclosed in U.S. Pat. No. 2,890,557, dated June 16, 1959.

As the needle assembly passes through the transfer area, before and after the central point of tangency of the two turrets, the fixed cam 14 is cut so that the needle assembly 11' is lowered, ejecting the charge of powder into the lower capsule body 15. Sleeve 12 is lowered to touch and seal lightly to the capsule body and piston 11 pushes powder out and into the body.

After the capsule turret 1 has cleared the filling area, plungers 17 and 20 are brought together, forming the complete capsule assembly in conventional manner. The upper body 18 fits over the lower body 15 squeezing the powder into the upper body section. The body sections may then be tacked together by means of a heat spot in conventional manner, or delivered by friction closure alone.

The capsules are fed into turret 1 preferably by automatic means which may be conventional, as shown in the above mentioned patent.

FIG. 6 shows a developed view of a portion of cam 14 illustrating the grooves 14a, 14b. Groove 14a controls the piston and groove 14b controls the sleeve and the needle. In the area marked "FILL" in FIG. 6, the piston is retracted upwardly to receive the powder. Thereafter, moving to the left of FIG. 6, the needle is retracted slightly to permit doctoring of the needle. Then the piston is pushed down by the groove 14a in the "EJECT" area of FIG. 6 so as to eject the powder into a capsule. The part 14e of cam 14 in the "FILL" area is preferably made of a separate piece so as to permit adjustment of the amount of powder charge, as shown in FIG. 7.

At the eject position, the upper cam surface 60 is pivotally mounted at point 61 and spring loaded by spring 62. The purpose of this is to provide a yielding surface and detecting means to detect any malfunction which might jam or damage the needle. For instance, if the lower capsule body was cocked out of position or inserted upside down in its turret, then that would cause an interference which would jam or damage the needle. Therefore, in such event, the pivotally mounted cam surface 60 would rotate clockwise in FIG. 6 and take the pressure off the needle and preferably, at the same time, actuate a switch 63, which may be connected to stop control means 64 and/or warning means.

FIG. 7 illustrates how the filling charge may be made adjustable by splitting a section of the cam 14 into two pieces 14d and 14e, each containing one of the grooves 14a, 14b. The spacings between the cam pieces 14d and 14e and, therefore, the spacing between the grooves 11a and 11b, may be adjusted by means of the adjustment handle 52, which is connected to a threaded rod 53, which is connected to a threaded portion 54 in the cam piece 14d. A similar threaded rod 53' is connected to the rod 53 by means of the chain 55 and sprockets 56 and 57. Therefore, by adjusting the spacing between the cam pieces, and therefore, the grooves 14a and 14b in the filling portion of the cam cycle, the amount of the powder charge in the needles may be carefully adjusted, while the machine is in motion or standing still, and all needles are adjusted the same amount simultaneously as they approach the filling area.

Claims

I claim:

1. In a machine filling powder into capsules,

a first turret rotatably mounted and adapted to carry capsule bodies along its periphery,

a second turret rotatably mounted and adapted to carry powder filler needle assemblies spaced along its periphery,

said first and second turrets being arranged to rotate continuously in a generally overlapping intermeshing tangential relation,

a plurality of radial slides mounted on said filler needle assembly carrying second turret, one of said filler needle assemblies being mounted on each of said slides,

means to cam said slides radially to substantially follow the circular motion of said capsule bodies mounted on said first turret for a predetermined distance before and after the central point of tangency of the first and second turrets,

whereby said needles are in position to fill said capsule bodies for a pre-determined distance before and after a central point of tangency during continuous motion of said turrets.

2. Apparatus as in claim 1 wherein said filler needle assemblies each comprise a reciprocatable sleeve, a piston reciprocatably mounted in said sleeve, and means to cam said sleeve and said piston axially.

3. Apparatus as in claim 1 wherein said needle assemblies each have a reciprocatable sleeve and a reciprocatable piston,

a reservoir adapted to contain powder, said reservoir comprising a flexible diaphragm,

means to position said pick-up needle assemblies over said flexible diaphragm containing said powder,

ram means located under said flexible diaphragm and means to operate said ram means to push powder to said needle assemblies.

4. Apparatus as in claim 3 having means to reciprocate said sleeve and said piston in each needle assembly.

5. Apparatus as in claim 3 wherein said bodies are mounted on a first turret, said needles are mounted on a second turret, and said diaphragm reservoir has an annular trough configuration mounted on a third rotatable turret and said third turret has a plurality of rams mounted to reciprocate underneath said diaphragm, whereby as said second and third turrets rotate in tangential relationship, said rams are adapted to insert powder into each of said needles as said needles pass through the area of tangency of said turrets with continuous motion.

6. A first turret rotatably mounted and adapted to carry capsules along its periphery,

a second turret rotatably mounted and carrying work members spaced along its periphery,

said first and second turrets being arranged in a generally tangential overlapping relation,

a plurality of radial slides mounted on said second carrying turret, each of said work members being mounted on one of said slides,

means to cam said slides to substantially follow the circular motion of said capsules mounted on the first turret for a predetermined distance before and after the central point of tangency of the first and second turrets,

whereby said work members are in the same axes as said capsules for a predetermined distance before and after a central point of tangency with continuous motion of said turrets.

7. Apparatus as in claim 6 wherein the path of said work members is modified to register the work members and bodies at three spaced points and approximately register the work members and bodies between and slightly beyond said points.

8. Apparatus as in claim 6 wherein said work members are powder filling needles which are in substantial alignment within the filling sector, the size of the powder charge being smaller than the capsule body so as to leave room for air escape as the powder is ejected into said body.

9. Apparatus as in claim 6 having a movably mounted spring loaded cam surface arranged to detect improper body positions, and a contact switch arranged to be activated by said detection cam surface, said switch being connected to stop the machine to prevent damage.

10. Apparatus as in claim 8 wherein said needles have a porous filter and means are provided to apply vacuum to said needles.

11. Apparatus as in claim 10 having means to apply air pressure to said needles.