US3612271A

US3612271A - Pneumatic capsule separator

Info

Publication number: US3612271A
Application number: US853808A
Authority: US
Inventors: Richard C Behling
Original assignee: Geigy Chemical Corp
Current assignee: Novartis Corp
Priority date: 1969-08-28
Filing date: 1969-08-28
Publication date: 1971-10-12
Anticipated expiration: 1988-10-12
Also published as: CA933490A

Abstract

A mass of identical capsules disposed in a single layer and each containing a charge of medicament flows by gravity down an inclined chute. Each capsule is intended to contain a prescribed standard amount of medicament which, by weight and composition, is identical to the charges in all the other capsules. Incompletely charged capsules, being lighter than the others, are blown out of the layer by a stream of air which deposits them in a collection chamber from which they are removed by suction to a point of discharge.

Description

United States Patent 72 Inventor Rich ardQBehling Goshen, N.Y. [21] Appl. No. 853,808 [22] Filed Aug. 28, 1969 [54] PNEUMATIC CAPSULE SEPARATOR 8 Claims, 6 Drawing Figs.

[52] U.S.Cl

[56] References Cited UNITED STATES PATENTS 1,987,640 1/1935 Rothgarm. 209/117 X 3,097,161 7/1963 Dudyak 209/137 X 3,429,438 2/1969 Palmen et a1. 209/137 Primary Examiner-Allen N. Knowles Attorney-Townshend & Meserole ABSTRACT: A mass of identical capsules disposed in a single layer and each containing a charge of medicament flows by gravity down an inclined chute. Each capsule is intended to contain a prescribed standard amount of medicament which,

209/74, by weight and composition, is identical to the charges in all the 209/l21,209/11S [51] Int. Cl B071: 13/10 [50] Field of Search other capsules. incompletely charged capsules, being lighter than the others, are blown out of the layer by a stream of air 209/ 1 15, which deposits them in a collection chamber m which they are removed by suction to a point of discharge.

PATENIED um I 2 H371 SHEEI 1 OF RICHARD C. BEHLING ATroRNEm PATENTEU um I 2 l97| saw 2 BF 2 INVENTOR RICHARD C. BEHLING ATTORNEYS,

1 PNEUMATIC CAPSULE SEPARATOR BACKGROUND In the commercial mass production or capsules and/or pellets intended to contain or comprise equal prescribed amounts, by weight, of identical composition material, the

pharmaceutical industry finds it inevitable that some will lack sufficient material to meet the required weight standard or its permissible tolerances. Those must be removed before the product can be marketed. The prior art, best epitomized in U.S. Pat. No. 3,097,16I to Dudyak, teaches pneumatic separation and sorting of a mass of capsules sliding by gravity down an inclined chute by projecting a blast of air into the mass in such volume, pressure, and direction that it lifts out of and above the moving mass only those lighter capsules which do not contain the prescribed weight of medicament. Those capsules which contain the prescribed quantity, by weight, of medicament are too heavy to be lifted by the air blast and so are not separated from the mass. The lighter weight capsules are carried by the air blast against a mechanical divider plate which directs them into a separate path of travel and into a collection receptacle. 7

Otherwise stated: The prior art teaches pneumatic separation of incompletely charged capsules by lifting them in an airstream which carries them into impact against mechanical guide means which diverts them into a path of travel separate from that of the main body and in which they travel by gravity to a point of discharge. However, the prior art does not teach the use of suction to divert the airlifted capsules into a path of travel different than the path of travel of the main body.

Prior to the advent of the present invention, the art has relied solely upon the force of a stream of air under positive pressure to lift incompletely charged capsules from the main body of the mass and carry them away. This requires very careful regulation of the air pressure. It the force of the airstream is too great all or a majority of the mass of capsules will be lifted from the main body and discarded as rejects. If the air pressure is not high enough to lift out the incompletely charged (lighter) capsules they will not be separated from the main body. For that reason the prior art has been concerned only with regulation of the airblast pressure at its source; the

objective being to maintain an airblast stream at a force suflicient to lift incompletely charged capsules out of the main body and carry them to an elevation above the main body at which they are either diverted by mechanical guide means or fall by gravity into a path of travel leading to a point of discharge as rejects.

In the pneumatic capsule separators of the prior art the positive pressure airstream must not only exert enough force to lift incompletely charged capsules out of the main body but also it must be sufficiently powerful to perform the additional function of conveying those capsules bodily over the distance between their point of separation from the main body and the point at which they are mechanically diverted or fall by gravity from the airstream. This added burden of conveying after lifting necessarily requires that the airstream pressure be greater than the pressure needed only to lifi the incompletely charged capsules from the main body; which makes it an extremely difficult matter to regulate the very small pressure differential so that the force of the airstream will not lift some acceptable capsules for discharge together with the rejects.

SUMMARY OF THE INVENTION The present invention follows prior art practice to the extent that it makes use of a stream of air under pressure blowing upwardly through a mass of capsules or pellets moving in a single layer, thereby separating out and lifting above the surface of the layer all those capsules or pellets which are, in weight, below a prescribed standard. It departs from and improves upon the aforesaid prior art practice in the manner and means by which imperfect capsules or pellets are caused to be lifted out of the moving layer, and in the manner and means by which the elevated capsules or pellets are removed and conveyed to a point of discharge as rejects.

In the practice of the present invention, the pressure of the airstream used to separate the imperfect capsules or pellets is just enough to lift them above the upper surface level of the moving layer, at which elevation they are subjected to suction which pulls them to a point of discharge. The separation and removal of the rejects is accomplished by the push-pull action of air under pressure combined with suction. This combination, employed as herein disclosed, effectively prevents inadvertent carryover of acceptable capsules or pellets for discharge as rejects.

przscalvnou or THE oaswmos FIG. I is a side elevation of a pneumatic separator embodying the present invention.

FIG. 2 is a sectional view on line 2-2 of FIG. I. FIG. 3 is a fragmentary sectional view on line 3-3 of FIG. 1 J

FIG. 4 is a sectional view on line 4-4 of FIG. 2.

FIG. 5 is a sectional view on line 5-5 ofFIG. 2.

FIG. 6 is a fragmentary sectional view on line 6-6 of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the embodiment "of the invention as herein shown and described, a mass of charged capsules is fed from a supply source 10 onto the upper end of a downwardly inclined chute having a flat bottom II and parallel upstanding sidewalls l2. Thechute is inclined at an angle of substantially 45 and the height of its sidewalls is only slightly greater than the thickness of a capsule. TI-Ie capsules are fed from the supply source in such manner that they form a single layer on the flat bottom 11 of the chute and slide thereon by gravity beneath a hood 13 covering the open top of the chute to prevent loss of capsules by bouncing or jostling. The roof of the hood is inclined downwardly from its upstream end to its downstream end, at which end it is proximate the top edges of the chute sidewalls 12. The lower end of the chute carries an extension 14 for discharge of capsules into a bin 15.

Intermediate the lower end of the chute and the hood I3 chute pases through a separation station constituted of an air pressure manifold 16 carried by the chute and extending therefrom beneath its bottom VII, and a tubular suction manifold I7 also carried by the chute and extending therefrom above its top opposite the air pressure manifold 16. The two manifolds are aligned axially on an axis that is perpendicular to the plane of the flat chute bottom .11 and which panes through the center of an air aperture 18 through the bottom of the chute. Aperture 18 is in the form of a narrow slot with parallel sides that extends transversely across the full width of the chute bottom between its sidewalls and perpendicular thereto. The width of the slot is less than the overall thickness of a capsule; which assures that all capsules passing over the slot will bridge it and cannot become lodged therein.

Air pressure manifold 16 is a boxlike chamber in open communication through its bottom with the outlet of an air blower I9 secured to and depending from the body of the chute assembly by bracket means 20. The top edge of the box seats a complemental frame 21 in which is mounted an air guide member 22. This guide as here shown is formed as a deep grid in which the crossed bars are walls circumscribing air channels of uniform square cross section and'parallel to the longitudinal axis of alignment of the two manifolds l6 and 17. The top face of the grid 22 is flush with the top face of its mounting frame 2] and both are in engagement with the undersurface of the chute bottom 11, as shown in FIG. 3. Grid frame 21 is fixedly attached to the air pressure manifold 16 between an opposed pair of its walls which, as shown in FIG. 5, extend above the chute assembly at the sides thereof. The inner faces of these walls have secured thereto fixed internal flange strips 23 which seat upon the top edges of the chute sidewalls l2 and provide support for the manifold. A stove bolt 24 (FIG. 6) threaded in a bracket 25 fixed to and depending from the bottom 11 of the chute downstream from the air pressure manifold 16 provides an adjustable stop bearing on a wall of the manifold to hold it against downward sliding movement on the chute and enables adjustment of .the manifold longitudinally of the chute to center the airflow guide grid 22 relative to the air passage slot 18.

Tile suction manifold 17, as here shown, is a chamber mounted at its base on the chute assembly over the top thereof and in axial alignment with the air pressure manifold 16. It seats at its base on the top edgesof the chute sidewalls 12 in open communication with the chute, and is coupled at its upper end to a flexible hose 26 that is a conduit which leads to and is in communication with theinlet tube 27 of a substantially boxlike receptacle 28 for capsules rejected at the separation station. A pipe 29 extends through the bottom of the receptacle 28 with its upper end spaced slightly below the top of the receptacle and with its lower end in connection with a conduit 29 which leads to a source of suction 30.

The downstream wall of the suction manifold 17 carries on its inner face an inclined baffle 31 which is adjustable to a selective elevation above the top surface level of a layer of capsules sliding down the chute.

METHOD OF OPERATION In the practice of the present invention, a mas of medicament-charged capsules is fed from the supply source onto the upper end of the flat bottom 11 of the chute. The capsules form a single layer on the chute bottom andslide by gravity down the chute and into the separation station. As they pass over the air slot 18 they are subjected to the action of a stream of air issuingupwardly through the slot from the manifold 16 underpressure from the blower 19. The blower pressure is such that the force of the airstream issuing from the slot 18 is just enough to lift out of the moving layer of capsule all those which weigh less than a prescribed standard weight and present them to the closely overlying intake of the suction manifold 17 at its base.

Those capsules lifted from the main body and presented to the intake of the manifold 17 are sucked into the manifold chamber and then through conduit 26 and tube 27 into the rejects collection receptacle 28 from which they may be removed through an access port (not shown). Those capsules which meet the prescribed weight standard are too heavy to be lifted by the airstream issuing from the slot 18 and in consequence will slide across the slot and continue their travel down the chute to drop into the acceptable capsule storage bin 15.

When the capsules being processed are of less than conventional thickness, the baffle 31 may be lowered between the sidewalls of the chute to a position at which its leading edge is just above the top level of the capsule layer, so that it picks up the lifted capsules and guides them into the suction manifold.

[t is apparent from the foregoing description that incompletely charged capsules, being lighter than the prescribed standard individual weight for the mass of capsules being processed, will be airlifted (pushed) above the moving layer of heavier standard weight capsules to a position from which they are pulled by suction into a path of travel separate from the path of travel of the heavier capsules. In effect, separation is accomplished by the simultaneous application of air under pressure against one face of the moving layer of capsules and suction to its opposite face.

The principles upon which this invention is bases are such that substantial variations from the structure shown and described herein may be made. For example: the chute, being a stationary conveyor, could be replaced by a travelling screen belt conveyor disposed horizontally instead of at an incline. Tl-le inclined chute arrangement is preferred because it is far less expensive to install and maintain than a traveling belt conveyor and does not require the expenditure of power necessary to drive a belt.

I claim:

' 1. Apparatus for pneumatically separating and sorting a mass of capsules of identical configuration and containing a filler material of the same composition, which comprises, in combination: a capsule-feeding station; a capsule collection station; a capsule-separating station between the feeding and collection stations; a conveyor for passing a single layer mass of the capsule from the feeding station, through the separating station and to the collection station; means at the separating station operative to blow a confined stream of air through one face of the conveyor at substantially a right angle thereto; means also at the separating station operative to apply suction adjacent the oppodte face of the conveyor over an area corresponding to the cross sectional area of the confined airstream and in alignment therewith; whereby to pick up capsules blown from a layer of capsules on the conveyor; a source of suction; and a conduit connecting said source of suction and said suction-applying means for carrying away capsules blown from the conveyor by force of the airstream.

2. In the apparatus of claim 1, said conduit including a capsule-trapping chamber located between the source of suction and the suction-applying means.

3. Apparatus for sorting and separating properly filled capsules from improperly filled and therefore lighter capsules, which comprises, in combination; aninclined chute; means for feeding a mass mixture of the capsules to the upper end of the chute for passage by gravity down the chute to discharge at its lower end; means for blowing a stream of air through the moving mass of capsules at an angle to the path of travel of the mass, thereby separating the improperly filled lighter capsules from the properly filled heavier capsules; and suction means operative in the area of influence of the'sirstream to draw off the separated lighter capsules and convey them away from the mas of capsules movingby gravity down the chute. Y

4. in the apparatus of clairn'3, the angle of the airstream relative to the path of travel of the mass of capsules being substantially 5. In the apparatus of claim 3, said suction means including a manifold chamber having an intake disposed within the area of influence of the airstream.

6. In the apparatus of claim 3, the chute having in its bottom a narrow slot for the upward passage of air from the air blowing means; an air pressure manifold beneath the chute bottom and having an outlet in communication with the slot and an inlet in communication with the air blowing means; and said suction means including a suction manifold having an intake spanning the top of the chute immediately above the slot.

7. The method of separating and sorting a mass of capsules of uniform shape and thickness into a group in which all the capsules are individually of the same predetermined standard weight, and into a different group consisting of capsules of less than the standard weight, which comprises: passing the mass of capsules by gravity down an inclined chute in a path of travel leading to a point of collection; blowing through the moving mass a stream of air at such volume, velocity, and direction that it carries out of and separates from the mass only those capsules which are of less than the standard weight; applying suction to the separated capsules as they leave the mass and thereby diverting them into a path of travel different than the path followed by the standard weight capsules and leading to a different point of collection.

8. The method of separating and sorting a mass of capsules of uniform shape and thickness into a group in which all the capsules are individually of the same predetermined standard weight, and into a different group consisting of capsules of less than the standard weight, which comprises: blowing upwardly through the bottom of an inclined chute an unbroken stream of air extending transversely entirely across the chute at a unifon'n thickness and velocity such that it allows the passage therethrough only of capsules having the standard weight;

passing the mass of capsules in a single layer down the chute

Claims

1. Apparatus for pneumatically separating and sorting a mass of capsules of identical configuration and containing a filler material of the same composition, which comprises, in combination: a capsule-feeding station; a capsule collection station; a capsule-separating station between the feeding and collection stations; a conveyor for passing a single layer mass of the capsule from the feeding station, through the separating station and to the collection station; means at the separating station operative to blow a confined stream of air through one face of the conveyor at substantially a right angle thereto; means also at the separating station operative to apply suction adjacent the opposite face of the conveyor over an area corresponding to the cross-sectional area of the confined airstream and in alignment therewith; whereby to pick up capsules blown from a layer of capsules on the conveyor; a source of suction; and a conduit connecting said source of suction and said suction-applying means for carrying away capsules blown from the conveyor by force of the airstream.

3. Apparatus for sorting and separating properly filled capsules from improperly filled and therefore lighter capsules, which comprises, in combination; an inclined chute; means for feeding a mass mixture of the capsules to the upper end of the chute for passage by gravity down the chute to discharge at its lower end; means for blowing a stream of air through the moving mass of capsules at an angle to the path of travel of the mass, thereby separating the improperly filled lighter capsules from the properly filled heavier capsules; and suction means operative in the area of influence of the airstream to draw off the separated lighter capsules and convey them away from the mass of capsules moving by gravity down the chute.

4. In the apparatus of claim 3, the angle of the airstream relative to the path of travel of the mass of capsules being substantially 90*.

5. In the apparatus of claim 3, said suction means including a manifold chamber having an intake disposed within the area of influence of the airstream.

8. The method of separating and sorting a mass of capsules of uniform shape and thickness into a group in which all the capsules are individually of the same predetermined standard weight, and into a different group consisting of capsules of less than the standard weight, which comprises: blowing upwardly through the bottom of an inclined chute an unbroken stream of air extending transversely entirely across the chute at a uniform thickness and velocity such that it allows the passage therethrough only of capsules having the standard weight; passing the mass of capsules in a single layer down the chute by gravity into the up-blowing airstream whereby the standard weight capsules will pass through the airstream and continue down the chute to a collection point, and whereby the airstream will lift out and separate and separate from the mass those capsules which are below the standard weight; and conveying the separated lighter capsules to a different point of collection by means of suction applied to the lighter capsules as they are separated from the mass.