IL46878A - Pick-off mechanism for capsule inspection machine - Google Patents

Abstract

A pick-off mechanism for a high-speed medicinal capsule inspection machine or the like. Bulk capsules are loaded from a hopper to a chain conveyor, rectified, and transferred to an inspection head. A circumferential series of rolls on the head defines vertical grooves to receive and spin capsules on their axes. The head indexes forward to carry capsules stepwise from the loading station, through an optical-electronic inspection station, to a transfer point. There, the capsules are transferred to a pick-off wheel, which indexes forward in timed relation with the head. The capsules are received on spaced seats on the pick-off wheel, and held thereon by suction. Each unacceptable capsule is swept off the pick-off wheel at an early point in the capsule movement on the pick-off wheel, by projecting a reject arm into the capsule path in response to the inspection results. The rejected capsules fall to a reject chute. Acceptable capsules are carried further by the wheel to a discharge point, where a cam removes them to an accept chute. [US3920541A]

Description

46878/2 PICK-OFF MECHANISM FOR CAPSULE INSPECTION MACHINE f The present invention relates to a pick-off mechanism for a high-speed capsule inspection machine. Bulk capsules are loaded from a hopper to a chain conveyor, rectified, and transferred to an inspection head. A circumferential series of rolls on the head defines vertical grooves to receive and spin capsules on their axes. The head indexes forward to carry capsules stepwise from the loading station, through an optical-electronic inspection station, to a transfer point. There, the capsules are transferred to a pick-off wheel, which indexes forward in timed relation with the head. The capsules are received on spaced seats on the pick-off wheel, and held thereon by suction. Each unacceptable capsule is swept off the pick-off wheel, at an early point in the capsule movement on the pick-off wheel, by projecting a reject arm into the capsule path in response to the inspection results. The rejected capsules fall to a reject chute. Acceptable capsules are carried further by the wheel to a discharge point, where a cam removes them to an accept chute.

This invention relates to a pick-off mechanism for a capsule classifying machine such as the inspection machine shown in U. S. Patent 3,756,402, dated September 4, 1973.

In such machines, the inspection head comprises a circumferential series of spinning rolls which define between them a series of capsule-receiving grooves in which the capsules spin in vertical position and are retained by air flow through suction passages between the rolls. The head indexes forward past a loading station where it picks up capsules and thence to an inspection station where the capsules are inspected as they are rotated on their axes by the spinning rolls. The capsules are then carried forward to a reject station where unacceptable capsules are discharged by cutting off the suction which retains them and applying instead an air blast to dislodge them. Acceptable capsules remain on the head and are carried to a later position where they are discharged by cutting off the suction and applying an air blast. The inspection apparatus operates at a high rate, as to inspect from 600 to 1200 capsules per minute.

The acceptance and rejection of vinspected capsules by selective control of air flow in response to the inspection result, as in Patent No. 3,756,402, is generally satisfactory in many inspection operations, especially at lower operating speeds. But greater precision and reliability is desired in effecting classification between acceptable and unacceptable capsules as determined by the inspection results, especially at high operating rates. The present invention provides such greater precision and reliability, and produces separation with fewer acceptable capsules being included in the rejected group and fewer unacceptable capsules being included in the accepted group. It also causes less danger of damage to the capsules, especially danger that the caps and bodies of capsules will be separated from each other as the capsules proceed through the classifying operation.

In accordance with the present invention, capsules are carried in spaced relation, preferably sidewise, along a path as on the inspection head of the inspection mechanism. After inspection thereon, the capsules are carried to a transfer point at which they are transferred to seats on a pick-off wheel which indexes in timed sequence with the inspection head and carries the capsules along a classification path. The path of capsules on the pick-off wheel is substantially tangent to the path of capsules on the inspection head at the transfer point, and a smooth flow of capsules from the inspection head to the transfer wheel is produced. The capsule seats on the wheel are narrow concave seats at the outer periphery of the wheel which carry the capsules in a clear-standing outward position and in well- spaced relation so as to facilitate selective removal. Transfer is effected by cutting off suction to the grooves in the inspection head at the transfer point and applying suction at the capsule-receiving seats on the pick-off wheel. As the wheel indexes forward from the transfer point, it carries capsules along a classification path, first to a reject position at which, when the capsule is to be rejected, a reject arms is advanced, e.g. , electromagnetically , into the path of the unacceptable capsule on the pick-off wheel, so that such capsule is swept from the wheel . to a reject chute as the wheel progresses.

When the capsule is an acceptable capsule, the reject arm is not projected into the capsule path but remains retracted, and the acceptable capsule is carried to a later point at which it is removed from the pick-off wheel by a pick-off cam. The capsules are held stationary without rotating on the pick-off wheel and the suction holding the capsules on the pick-off wheel can be regulated to exert the minimum force needed to hold the non-rotating capsules. Also, the pick-off cam discharges the acceptable capsules from the mechanism less forcefully than did the air-blast previously used. More precise classification of the capsules with less damage is obtained.

The pick-off wheel desirably has seats which are divided into two separate spaced seat portions on opposite sides of a central groove and disposed between radial faces on the wheel, and the pick-off arm has three fingers, the central one of which enters the groove and the outer ones of which overlap the radial faces, so as to engage a capsule at its ends and to engage a half capsule at two places, to ensure the removal thereof from the pick-off wheel.

The accompanying drawings illustrate the invention and show an exemplifying perferred embodiment. In such drawings: Fig 1 is a somewhat diagrammatic vertical section of a capsule inspection machine embodying the pick-off mechanism of the present invention; Fig. 2 is a plan view, with parts shown in section, showing the inspection head and the relation therewith of the pick-off wheel and its associated mechanism; Fig. 3 is an end view of the pick-off cam shown in Fig 2; Fig. 4 is a section taken on the line 4-4 of Fig. 2; and Fig. 5 is a section taken on the line 5-5 of Fig. 2.

The capsule sorting machine shown in the drawings is for inspection of conventional capsules 10, consisting of a body part and cap, each having a generally cylindrical side wall and rounded end. As delivered from the capsule making machine, the capsules are assembled with sufficient looseness to permit the caps and bodies to be disassembled for filling, and care must be exercised to avoid such harsh treatment as to cause capsules to separate during handling.

The machine shown in the drawings comprises a frame 14 defining a lower compartment 16 containing a motor 18 which drives through a transmission 20 containing a clutch and brake. A conveyor 22 mounted on the frame extends between a pair of lower sprockets 24 and a pair of upper sprockets forming the sides of a transfer wheel 26. The conveyor consists of a series of capsule-receiving buckets 28 carried between a pair of side chains 30 engaged about the sprockets 24 and 26. The upper stretch of the conveyor extends through the bottom of a small hopper 32, from which the buckets 28 are filled with capsules. For inspection, the capsules must all have the same orientation, the conveyor runs through a rectifying, zone 34, where mechanism is provided to cause body-forward capsules to be reversed to a cap-forward position. From the rectifying zone 34, the capsules are carried to the transfer wheel 26, from which they are transferred to an inspection head 36. The head and the conveyor and transfer wheel are driven in timed relation from the motor 18 and transmission 20, as by separate timing belts 21 and 23.

The inspection head, shown in horizontal and vertical sections in Figs. 2 and 4, comprises a circumferential series of spin rolls 50 mounted about the periphery of a carrier 52 having a hub 54 mounted on a main shaft 56.

Each roll 50 is fixed on a shaft 58 which carries a spin gear 60 at its lower end. All the spin gears 60 of the several spin rolls are in constant engagement with a ring gear 62, which is continuously driven from a spin drive gear 64 mounted on a parallel shaft as shown in Fig. 2. Each pair of rolls 50 forms a capsule-receiving groove 66 between them. The rolls lie in close clearance relation at their sides and ends with shaped portions of the periphery and end flanges of the carrier 52, and the close clearances substantially close the capsule-receiving grooves 66 at their inner periphery. The bottom of each groove 66 communicates with an air passage 68 leading to a hollow cavity 70 in the carrier 52. A valve block 72 is seated in that hollow cavity and defines a vacuum chamber 74 which is in communication with the air passages 68 over a predetermined arc of their travel, and is blocked from communication with such passages 68 over another portion of their travel by an arcuate portion of the valve block 72.

As shown in Figs. 1 and 4, each spin roll 50 is desirably formed with a downward-facing shoulder 51 intermediate its length, between an upper portion adapted to engage the body of a capsule and a lower portion of slightly smaller diameter adapted to engage the cap of a capsule.

The capsules are carried by the spinning rolls in an inverted position, with the cap at the bottom and the body at the top. Air flow into the grooves 66 and through the passages 68 serve to retain the capsules in the grooves 66 in contact with the rolls. The rolls spin continuously and thus continuously spin the capsules on their axes as they are carried by the inspection head.

The inspection head is indexed forward, stepwise. To produce the desired indexing, its shaft 56 is connected to an indexing drive 76 shown in Fig. 1, which is driven by the timing belt 21 from the transmission 20. A take-off belt 78 drives a transmission 80 for the spin drive wheel 64. The arrangement is such that the spin drive wheel 64 rotates continuously while the main shaft 56 of the inspection head 36 indexes forward between periods of rest during which capsule feeding, inspection, and transfer steps take place.

Capsules are fed to the inspection head at the feed station 35 at the right as shown in Figs. 1-4. The transfer wheel 26 has delivery fingers 82 with suction seats at their ends. Such fingers advance through the conveyor buckets 28 as they travel about the transfer wheel 26, to lift the capsules 10 to an outward-standing position as shown in Fig. 4. In this position, a capsule lies closely opposite a capsule-receiving groove 66 on the inspection head and as the capsule reaches this position, the suction holding it on the finger 82 is cut off and it is drawn into the groove 66 of the head by the airflow induced by the suction passage 68. In the groove, the capsule is supported by the spinning rolls 50 and is spun on its axis.

As the inspection head 36 indexes forward, it carries the spinning capsules 10 to an inspection station 45 shown diagrammatically at the bottom of Fig. 2. Here the spinning capsules are illuminated by lightning system including a lamp 84 and are inspected by an inspection system 86 responsive to light reflected from the spinning capsule.

The inspection result is suitably processed and used to control the later classification of the capsules. After inspection, the capsules are carried through four additional indexing steps to a transfer station 55 where they are transferred to the pick-off wheel 40.

The pick-off wheel 40 comprises a rotary head having a series of six capsule receiving seats 88 spaced about its periphery. Each seat comprises a short upper portion 87 and a lower portion 89, on opposite sides of a central peripheral groove 90 between them. The seat portions terminate at their outer ends at radial faces on the wheel 40. Each seat portion 87 and 89 is connected by an air passage 92 to a vacuum chamber 93 within the wheel 40. The seat portions act together to support a whole capsule and are adapted to act individually to support separate caps or bodies of capsules.

The wheel 40 is mounted on a hollow shaft 94 journaled in spaced bearings 96 and 98 in a bearing block 100, as shown in Fig. 4. In the space between the bearings, the hollow shaft 94 has a side outlet opening 102, and the surrounding space is connected through a vacuum passage 104 shown in Fig. 5 to a vacuum line 106. The lower end of the shaft 94 carries a drive gear 108, in constant mesh with a driving gear 110 mounted on the main shaft 56 of the inspection head 36. Accordingly, the pick-off wheel 40 and its shaft are driven in timed relation with the indexing movements of the main shaft 56. As shown, the pick-off wheel 40 is half the diameter of the inspection head 36 and has six capsule- receiving seats 88, whereas the inspection head 36 has twelve capsule-receiving grooves 66. Accordingly, the gears 108 and 110 have a, 2:1 drive ratio, and as each capsule containing groove 66 of the inspection head 36 is indexed to the transfer station 55, a seat 88 of the pick-off wheel will be indexed to that station simultaneously.

To transfer capsules from the inspection head 36 to the pick-off wheel 40, vacuum is continuously maintained within the wheel chamber 93 to draw air inward through the suction passages 92, so as to attract and hold capsules on the seats 88 of the pick-off wheel 40. In the inspection head, the vacuum chamber 74 extends from a point ahead of the position of the feed station, forward in the direction of indexing movement of the inspection head, i.e., clockwise, to a point just ahead of the position of the air passage 68 at the point of transfer to the pick-off wheel 40. Accordingly, as a groove 66 containing a capsule 10 reaches the transfer point, suction is cut off from its air passage 68, and the suction which retains the capsule 10 in the groove 66 is terminated. The capsule 10 is then attracted to the seat 88 on the pick-off wheel 40 by airflow to the passages 92, and is held on such seat by the suction continuously applied through the air passages 92. As the pick-off wheel 40 then indexes forward, counterclockwise in Fig. 2, it carries the capsule 10 first to the position 10a as the next adjacent seat 88 comes into transfer position to receive the next capsule from the inspection head 26.

If the capsule in the position 10a is an unacceptable capsule and is to be rejected, it will be swept off the pick-off wheel 40 during the next indexing motion. To effect such sweeping removal of a rejected capsule, a pick-off arm 120 is mounted for reciprocation between an inactive retracted position shown in full lines in Fig. 2 and an extended active position shown in dotted lines. The arm 120 is an elongated bar supported adjacent its center by a pivot arm 122 and connected at its rear end to the crank arm 124 of a rotary solenoid 126. The crank arm 124 is biased to its normal retracted position as shown in full lines, by a biasing spring, not shown.

Capsules swept from the wheel fall into the reject chute 42, the upper end of which is formed between an end wall 136 of the housing 14, a sloping shield 137 mounted on the mounting block which carries the bearings for the main shaft 56 and the shaft of the spin drive gear 64, and between the mounting block 100 for the pick-off wheel shaft 94 and a shielding wall 140 which shields the chute from the supporting and actuating mechanism for the pick-off arm 120. The actuating solenoid 126 for the pick-off arm 120, and the supporting arm 122 are conveniently mounted on a mounting plate 125 secured against the inner face of the housing wall 136, behind the shielding wall 140.

The forward end of the pick-off arm 120 is shaped as shown in Fig. 5, with three fingers 128, 129 and 130 at its forward end. Upon advance of the pick-off arm 120 to its active pick-off position, the fingers move into the path of the capsule carried by the pick-off wheel 40. The upper and lower fingers 128 and 130 overlap the top and bottom radial surfaces of the pick-off wheel 40 and the middle fingers 129 extends into the groove 90 between the upper and lower portions 87 and 89 of the seat. As the pick-off wheel 40 then advances in its next indexing movement, the unacceptable capsule moves to the position 10b where it is engaged by the fingers of the pick-off arm 120 and swept off the pick-off wheel 40 to the reject chute 42.

The rotary solenoid 126 is activated in response to the inspection result at the inspection station 45 shown in Fig. 2, and in timed relation with the movement of the inspected capsules, so that when an unacceptable capsule reaches the position 10a on the pick-off wheel, such rotary solenoid will be actuated to move the pick-off arm 120 to its active position where it will sweep the rejected capsule off the pick-off wheel 40 at the position of the capsule 10b, as the wheel advances in its next indexing movement.

If the capsule is acceptable, the solenoid is not actuated, and the pick-off arm 120 remains in its retracted inactive position. In such case, the acceptable capsule remains on its seat on the pick-off wheel and is carried past the position of the pick-off arm 120 to a later point at which it is removed from the wheel by a discharge cam 134. Such cam is fixedly positioned in the path of the capsules on the pick-off wheel 40 at a point spaced from the pick-off arm 120. The capsules swept off the pick-off wheel by the cam 134 are discharged to the accept chute 44 which feeds them to a container for acceptable capsules .

The cam 134 is conveniently mounted on the housing end wall 136 of the machine, as by a pair of bolts 139, and may be slidably adjustable in its mounting, as shown. The forward end of the cam is desirably shaped as shown in Fig. 3, with upper and lower fingers 133 and 135 which overlap the top and bottom surfaces of the head of the pick-off wheel 40, and with a central finger 137 which enters the groove 90 of that head.

Operation of the machine shown is as follows.

Capsules to be inspected are fed to the hopper 32, as from a capsule making machine. From the hopper, they are picked up by the buckets 28 of the continuously moving conveyor 22, which carries them through the rectifying zone 34 where any body-forward capsules are inverted to cap-forward positions. The capsules are then carried about the transfer wheel 26, and as they traverse the upper portion of such wheel, transfer fingers 82 are projected through the buckets 28 to lift the capsules out of the buckets to a transfer position as shown in Fig. 4. As each capsule reaches a position opposite a groove 66 of the inspection head 36, suection is cut off from the transfer finger and the capsule then moves into the groove 66 under the influence of the suction applied from the inspection wheel. The spin rolls 50 defining the groove 66 are rotating, and cause the capsule to spin on its axis. The inspection head 36 is indexed forward in successive steps to the inspection station 45, where each spinning capsule is inspected by the electro-optical system 84-86.

The indexing head then carries each inspected capsule forward to the transfer position 55 in alignment with a seat 88 on the pick-off wheel 40. At this point, the suction through the air passages 68 of the inspection head is cut off by the valve block 72 while suction is continuous through the passages at the pick-off seat 88. The capsule at the transfer position is thereby transferred to the seat 88 on the pick-off wheel and is thereafter carried on that seat. As the pick-off wheel indexes forward, if the capsule is unacceptable, the pick-off arm 120 is advanced by the rotary solenoid 126 to project its fingers 128-130 into the path of the capsule, and such fingers sweep the capsule at the position 10b from the pick-off wheel 40 to the reject chute 42. Acceptable capsules are not swept off at this point, but are carried forward three more indexing steps and are then swept off the pick-off wheel 40 by the discharge cam 134. The accepted capsules thus discharged from the pick-off wheel 40 are delivered by the chute 44 to a container 46. This pick-off mechanism provides precise classification of the capsules between accepted and rejected capsules based on the inspection results at the inspection station 45. It handles the capsules, especially the acceptable capsules, with a minimum of force and harshness, so as to minimize danger of damage to the capsules and of separation of the capsule caps from the capsule bodies.

Claims (10)

What is claimed is:

1. A pick-off mechanism for a capsule classifying machine having a carrier on which capsules to be classified are carried in spaced relation along a path, comprising a pick-off wheel having capsule receiving seats about its periphery and rotatable to carry capsules on said seats in a classification path, means to drive the wheel in timed relation with said carrier so as to present its seats successively in capsule-receiving position at a transfer station along said carrier path, means to cause capsules to transfer from the carrier to the wheel seats at said station and suction means to retain the capsules on the seats as they are advanced by the wheel along said classification path, a pick-off arm having a normal inactive position out of the classification path of capsules on said wheel and an active position in which it lies in such path at a first location so as to sweep a capsule of one class from the wheel at such location, means at a second location along the path of capsules on the wheel to remove capsules of another class from the wheel at such second location, and means to actuate said pick-off arm to its active position as a capsule of said one class approaches said first location

2. A pick-off mechanism as in claim 1 in which said carrier carries capsules sidewise along its path and said pick-off wheel carries capsules sidewise in a classifica tion path substantially tangent to said carrier path at said transfer station.

3. A pick-off mechanism as in claim 1 or 2 in which said pick-off wheel seats are spaced circumferentially about the wheel, and comprise axially-spaced seat portions adapted to engage axially-spaced portions of a capsule and to carry the same sidewise in a circular path as the wheel rotates, said seat portions being disposed on opposite sides of a groove about the wheel and extending from such groove to radial end faces spaced from each other a distance less than the length of the capsules, and said pick-off arm 10 comprises a central finger which in the active position of the arm lies in said groove, and two side fingers which in such position of the arm overlap said radial faces and straddle the seats, so that such three fingers are in a position to engage the ends and the middle of a capsule on a wheel seat and to engage at two spaced points a capsule cap or body held on one seat portion.

4. A pick-off mechanism as in any of claims 1 to 3 in which said pick-off wheel comprises circumferentially- spaced seats, each seat comprising two axially spaced portions 20 formed with concave faces to engage the cylindrical side surfaces of the body and cap of a capsule, separate suction passages to said two spaced portions, so as to cause the same to act together to retain a whole capsule and to act individually to retain separate caps and bodies thereon, said pick-off arm having spaced fingers which in the active position of the arm straddle each of said spaced potions to sweep therefrom either a whole capsule or a separated body or cap.

5. A pick-off mechanism as in any of claims 1 to 4 in which said carrier is a rotatable head having axially-disposed capsule-receiving grooves about its periphery, means to index said head forward to carry said grooves successively to a transfer point, and drive means interconnecting the pick-off wheel and said head to index the wheel forward in timed relation with the head to carry its seats to such transfer point concurrently with said grooves on the head.

6. A pick-off mechanism as in any of claims 1 to 5 in which the pick-off wheel has half as many seats as the head has grooves, and the wheel indexes at twice the speed of the head.

7. A pick-off mechanism as in any of claims 1 to 6 in which said carrier is a rotatable inspection head having a circumferential series of capsule receiving grooves, inspection means at one station about said head to inspect capsules in said grooves and to classify them into at least two classes, and means reponsive to said inspection means for selectively actuating said pick-off arm in timed sequence with the movements of the head and wheel to remove capsules of one class at the arm location.

8. A pick-off mechanism as in any of claims 1 to 7 in which said pick-off arm comprises an elongated arm, a supporting pivot arm pivotally mounted on a fixed pivot spaced from the path of said pick-off arm and pivotally connected to the pick-off arm to support it for longitudinal movement, and a drive device having an arm connected to a spaced point of the pick-off arm and operative when actuated to move the pick-off arm to its active position.

9. A pick-off mechanism as in any of claims 1 8 in which the drive device is a rotary solenoid having . operating arm in spaced generally parallel relation with said pivot arm.

10. A pick-off mechanism substantially as hereinbefore described. S.HOROWITZ S CO. AGENTS FOR APPLICANTS