US3542241A - Vacuum feeding apparatus - Google Patents

Description

United States Patent [72] inventor Stanley William Middleditch Potters Bar, England [21] Appl. No. 815,847 [22] Filed April 14, 1969 [45] Patented Nov. 24, 1970 [73] Assignee De La Rue Instruments Limited London, England a corporation [32] Priority April 26, 1968 [33] Great Britain [31] No. 19,862/68 [54] VACUUM FEEDING APPARATUS 8 Claims, 1 Drawing Fig.

52 U.S.Cl 221/211, 221/9; 214/8.5 [51] Int. Cl ..'B65g 59/04; B65h 3/08 [50] Field ofSearch 221/21 1, 9, 10,225, 221, 236;214/8.5

[56] References Cited UNITED STATES PATENTS 3,045,867 7/1962 Flynn 221/211 3,063,578 11/1962 Millar 22l/2l1X 3,456,816 7/1969 Galloway Primary Examiner-David M. Bockenck Attorney-Baldwin, Wight & Brown ABSTRACT: Apparatus for dispensing articles one at a time from a stack of such articles, characterised in that it comprises the combination of a. stack support means.

b. a suction gripper in a datum position for transferring said articles one by one to an unloading station,

c. means for advancing said stack support means towards said suction gripper for loading said gripper with the foremost article of said stack.

d. means adapted cyclically to reciprocate said suction gripper between said datum position and said unloading station after loading said suction gripper.

e. suction-sensitive means operable on loading of said suction gripper for arresting operation of said advancing means. and

f. control means for preventing reactuation of said advancing means until the suction gripper is returned to the datum position at the end olthe cycle.

VACUUM FEEDING APPARATUS This invention relates to apparatus for dispensing articles one at a time from a stack of such articles.

In particular this invention relates to sheet or article feeding apparatus of the type comprising a vertical stack or pile of horizontally disposed sheets or articles, an oscillatory suction lifting means connected to a source of vacuum adapted to remove sheets or articles singly from the top of the pile and transport them to a delivery stage and a pile elevator capable of maintaining the upper surface of the pile at a substantially constant position.

The invention is specifically intended for use in the feeding of banded assemblies of sheets, for example packets of banknotes, into the delivery stage of an automatic voucheroperated or card-operated cash dispensing machine. However, it may advantageously be applied to other analagous apparatus wherein it is desired to feed or dispense single sheets or articles into a delivery or receiving means in a reliable manner.

In the case of handling packets or assemblies of sheets considerable difficulties are experienced in maintaining the upper surface of the pile at a desired constant height withrespect to the suction lifting means because of the inherent inconsistent resilience or spring ofthe packets within the pile. For example packets of banknotes may include either/or both new and used notes and the tightness of the banding and the degree of wear or edge distortion of the notes will inevitably create a compressible assembly of indeterminate thickness. Ac cordingly, a free-pile height of approximately 20 inches may possess a compressibility in the order of 2 inches of vertical displacement.

On the one hand it is essential that the pile is sufficiently high to enable it to be acted upon by the suction lifting means in a positive and reliable manner before the commencement of the oscillatory movement of the lifting means and on the other hand it must notbe raised too or otherwise impede the return movement of the suction lifting means.

We have found that pile height sensing devices of the type well known in the printing industry are not capable of controlling the pile elevating means in accordance with the above requirements. For example, a conventional sensing arm adapted to bear upon the top of a pile is unable to sense accurately the free height of the pile because of the aforementioned inconsistent resiliency and, secondly, because the existence of the arm restricts vertical movement of the topmost packet whilst it is being acted upon by the suction lifting arm.

lt is also well known to employ an oscillatory suctionoperated device which is capable of ascending and descending upon the top of a pile and which is adapted to initiate operation of the pile elevating mechanism when it descends below a predetermined limit. This device may comprise a height detector which is arranged to oscillate in unison with a conventional suction sheet removal means, or alternatively it may comprise a single component of telescopic construction which is capable of performing the combined function of detecting and sheet lifting. Each of these known devices is satisfactory when used in conjunction with relatively nonresilient piles, such as virgin sheets of paper of the type encountered in the printing industry, but is incapable of acting satisfactorily upon resilient piles.

The present invention provides apparatus for dispensing articles one at a time from a stack of such articles, comprising:

a. stack support means,

b. a suction gripper in a datum position for transferring said articles one by one to an unloading station,

c. means for advancing said stack support means towards said suction gripper for loading said gripper with the foremost articles of said stack,

d. means adapted cyclically to reciprocate said suction gripper between said datum position and said unloading station after loading said suction gripper, Y

e. suction-sensitive means operable on loading of said suction gripper for arresting operation of said advancing means, and

high thereby to obstruct v f. control means for preventing reactuation of said advancing means until the suction gripper is returned to the datum position at the end of the cycle.

The apparatus may include means for breaking the suction when said suction gripper is in the unloading station, although the article may, for example, be mechanically removed from the gripper.

In one embodiment of the invention the suction gripper comprises a pair of downwardly directed suction cups, and said advancing means is arranged to lift said stack support means upwardly towards said cups, the suction cups being supported for sideways and upward movement from said datum position to said unloading station by a pair of slewing arms each pivoted about a horizontal axis to a substantially vertical angularly rotatable spindle.

One of said spindles may be angularly rotated by a reciprocable connecting rod pivotally connected at one end by a link to said spindle and pivotally connected at its other end to a rotatable cam disc, drive means being provided for rotating said cam disc through one revolution to effect cyclic movement of said suction gripper.

The cam disc may include a projection arranged to engage and pivot a lever, when the gripper is in the unloading position, to expose a port in a suction conduit for said suction gripper thereby to break the suction and release the article.

The advancing means preferably comprises an electric motor in an electrical circuit including a pressure-sensitive switch, constituting the suction-sensitive control means, in communication with said suction gripper and adapted to open on loading of said gripper, an electrical switch, constituting said second control means, being included in said circuit to coact with one of said slewing arms and arranged to open during the cyclic movement ofthe suction gripper.

A nonlimiting example of the invention will now be described with reference to the accompanying drawing which is a diagrammatic perspective view of the essential components of the article-dispensing apparatus. it will be appreciated that for reasons of clarity all structural framework and noncritical mechanical and electrical components have been omitted from the drawing.

A stack or pile l of banded packets la of banknotes is stacked vertically upon a horizontal pile support plate 2 which is capable of being elevated by a geared electric motor 3 by means of a sprocket and chain system shown diagrammatically at 4. The arrangement is such that energisation of the motor will cause the support plate and the packets disposed thereon to rise slowly.

Additionally a clutch (not shown) is incorporated in the transmission system to enable the support plate 1 to be operated manually for the purpose of servicing the apparatus or replenishing the supply pile. A suitable guiding means (not shown) is also provided externally of the pile of to maintain the packets in vertical alinement The suction lifting means comprises a suction gripper constituted by a pair of spaced downwardly-directed nonresilient suction cups 5 which are attached to a hollow beam 6 integral with a hollow transverse bar member 7. The extremities of the bar member are pivotally attached to a pair of parallel slewing arms 8 and 9, the opposite ends of which are pivotally mounted in the forked ends of two vertical shafts l0 and 11. The distance between the shafts l0 and 11 is identical to that of the effective length of the bar member 7, so that the latter member and the two arms 8 and 9 comprise a parallelogram linkage system. The arms 8 and 9 are free to pivot vertically within the fork ends by means of horizontal pin joints l2 and 13.

A linear cam plate 14 is fixedly attached to the framework of the apparatus and is provided with an upper cam surface 14a capable of coacting with the underside of the arm 8. The suction lifting assembly as referred to above is oscillated in an arcuate manner about the vertical shafts l0 and 11 by means of a crank disc 15 and a lever 16 fast with the shaft 10, the lever 16 and crank disc being connected by a connecting rod 17 pivoted thereto at its ends. The crank disc is driven in a unidirectional manner by means of a geared electric motor 18, the electrical energisationof which is broken by means (not shown) every whole revolution of the'disc thus to position the suction cups 5 above the pile 1 in the manner illustrated at the end ofa cycle. I

An inclined delivery chute 19 is attached to the framework of the apparatus and-is positioned immediately below the suction cups when they are in their extreme limit ofmovement, as indicated by the chain-dotted lines.

An upstanding brush 20 is provided adjacent to the side edge of the top of the pile 1 to strip off any packet which may have inadvertently adhered to the underside of the packet being acted upon by the lifting means.

The pneumatic system comprises an internal passageway formed within the beam 6 which terminates at the interior of the suction cups and extends vertically through the centre of the transverse member 7 to a connection pipe 21. The pipe 21 receives one end of a flexible tube 22 the opposite end of which is mounted upon a hollow cruciform junction member 23 in a fluid-tight manner. The upper vertical limb of the member 23 is provided with a pressure sensitive electrical switch S, and the side limbs 24 and 25 connect, respectively,

to a source of vacuum V, and an air inlet valve 26. The switch S, is provided with a pair of normally closed contacts which serve to break an electrical circuit for the elevating motor 3 when a predetermined degree of suction exists within the system.

The air inlet valve 26 comprises a resilient pad 26a mounted upon a lever 27 pivoted at 27a. The pad 26a is spring-loaded against the end of the hollow limb 25 thereby to seal same from atmospheric pressure. The opposite end of the lever 27 is capable of being deflected (as indicated by a'chain-dotted line) by a projection 28 attached to the periphery of the crank disc 15. Thus. when the disc is rotated to position the suction cups 5 above the chute 19 the air inlet valve 26 will open and admit atmospheric air into the system thus temporarily breaking the vacuum.

A second electrical switch S is provided for the purpose of immobilising the pile elevating means when the suction cups 5 are not situated in their'rest positions. i.e. above the pile 1. This switch is situated adjacent the cam' plate 14 and its operating blade is actuated by the underside of the arm 8. It thus closes the contacts only whilst the apparatus is in the position as illustrated.

The electric circuit to the pile elevating motor 3 comprises valve 26 will be opened to atmosphere thus breaking the of suction will not restart the pile elevating motor 3 because the circuit is broken by the switch 8:. It will further be realized that the oscillatory movement of the lifting means will cause the lever 8 to coact with the stationary cam surface 14 thereby to raise the suction cups. together with the packet adhered thereto, from the remainder of the pile. The return of the lifting means will follow an identical path and it therefore follows that the suction cups will descend over the pile and the possibility of obstructing or fouling the pile is eliminated.

The feeding means is thereafter positioned in readiness for the following feeding cycle which will again cause the pile to elevate if necessary.

Whilst a delivery chute is specifically referred to in the I description, any suitable alternative delivery arrangement may be employed. For example, the packet may be deposited into a slideable tray or fedinto the nip of a roller system.

The apparatus described above has a fail-safe feature in that if the vacuum pipes become disconnected or a hole formed therein so thatthe stack continues to rise after loading the gripper, the spring blade of switch S: will open thus stopping motor 3.

lclaim:

1. Apparatus for dispensing articles one at a time from a stack of such articles, characterised in that it comprises the the two switches S, and S wired in series configuration with a source of electricity. In actual practice this electrical circuit is only live whilst the apparatus associated withv the above described feeding means is in operation.

The operation of the feeding means is instigated from a stand-by or "prepare" input signal derived for example from the aforementioned associated cash-dispensing apparatus, which energises an electrical circuit to drive a vacuum pump thereby to create vacuum within the junction member 23 and energise the circuit for motor 3. Assuming that the top of the pile l is below the level of the underside of the suction cups 5 air will enter between same and the top of the pile accordingly the contacts of the switch S, will remain closed because there will be no buildup of suction within the system. The effect of this is, to energise the pile elevating motor 3 which serves to raise the pile 1. When the topmost packet in the pile contacts both of the suction cups suction will be created in the system and the contacts of the pressure-sensitive switch S, will open to break the circuit to the elevating motor 3. The apparatus is thus immediately ready for receiving an acceptance input signal from the apparatus above which energises the motor 18 which, through the medium of the crank disc 15, the connecting rod 17 and the lever 16 fast with the vertical shaft 10, oscillates the suction lifting means to the position, indicated by the chain-dotted line, above the delivery chute 19. At the end of this movement the air inlet combination of:

a. stack support means;

b. a suction gripper in a datum position for transferring said articles one by one to an unloading station;

c. means for advancing said stack support means towards said suction gripper for loading said gripper with the foremost article of said stack;

cl. means adapted cyclically to reciprocate said suction gripper between said datum position and said unloading station after loading said suction gripper;

e. suction-sensitive means operable on loading of said suction gripper for arresting operation of said advancing .means; and

f. control means for preventing reactuation of said advancing means until the suction gripper is returned to the datum position at the end of the cycle.

2. Apparatus according to claim 1 characterised in that the advancingmeans comprises a geared electric motor and the suction-sensitive means comprises a suction-sensitive electrical switch in an electrical circuit with said motor and in pneumatic communication with the suction gripper.

3. Apparatus according to claim 2 characterised in that the control means comprises an electrical switch in said electrical circuit.

4. Apparatus according to claim 3 characterised in that the suction gripper is attached to an arm adapted for movement in such a-manner that each article is lifted from the top of the stack and transported to the unloading station.

5. Apparatus according to claim 4 characterised in that the suction gripper is pivotally mounted to the extremities of a pair of parallel arms the opposite ends of which are pivotally attached to the framework of theapparatus.

6. Apparatus according to claim 5 characterised in that it further includes a fixedly mounted cam plate adapted to engage with one of the arms and a geared electric motor adapted to reciprocate said arm along the cam plate away from and towards said datum position via said unloading station.

7. Apparatus according to claim 4 characterised in that means are provided to admit atmospheric air into the suction gripper when it is at said unloading station.

8. Apparatus according to claim 1 characterised in that the suction gripper comprises at least one downwardly directed nonresilient suction cup.

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