US2934196A

US2934196A - Wrapping machines

Info

Publication number: US2934196A
Application number: US797115A
Authority: US
Inventors: Bennett John David; Walker Rowland
Original assignee: Forgrove Machinery Co Ltd
Current assignee: Forgrove Machinery Co Ltd
Priority date: 1958-03-28
Filing date: 1959-03-04
Publication date: 1960-04-26
Anticipated expiration: 1977-04-26
Also published as: GB853065A; DE1094656B

Description

April 26, 1960 Filed March 4, 1959 J. D. BENNETT ETAL 2,934,196

WRAPPING MACHINES 4 Sheets-Sheet I April 26, 1960 J. D. BENNETT ETAL 2,934,196

WRAPPING MACHINES 4 Sheets-Sheet 2 Filed March 4, 1959 Fig. 12.

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April 1960 J. D. BENNETT ETAL 2,934,196

WRAPPING MACHINES 4 Sheets-Sheet 3 Filed March 4, 1959 \A mm 7 1 7 m u n 0 m U w 3 M J. .H. m I w W m w /I 2 I 4 kw J April 25, 1960 J. D. BENNETT ETAL 2,934,196

WRAPPING MACHINES Filed March 4, 1959 4 Sheets-Sheet 4 United States Fatent WRAPPING MACHINES John David Bennett, Leeds, and Rowland Walker, Dewsbury, England, assignors to The For-grove Machinery Company Limited, Leeds, England, a company of Great Britain Application March 4, 1959, Serial No. 797,115

Claims priority, application Great Britain March 28, 1958 6 Claims. (Cl. 19824) -It is well known to convey tablets of confectionery standing on edge in the pockets of a conveyor chain from a moulding device to a transfer station, at which a reciprocating transfer pusher ejects the tablets in succession from the pockets in the chain. Apparatus of this character is described, for example, in US. specification No. 2,784,541.

Although the tablets may be carried on the chain as individual tablets, it is more usual for them to be so carried as a string of interconnected tablets joined to one another by thin webs of stock. In operation of such apparatus it has been the practice to remove individual badly formed tablets, or a succession of badly formed tablets, by hand from the pockets of the chain, and such removal inevitably results in distortion of the adjacent tablets. This procedure also involves abrupt stopping and restarting of the high speed pusher mechanism, which is mechanically disadvantageous.

The invention provides means whereby, in the event of faulty tablets being observed on the conveyor chain, the level of the pusher may be changed, without interrupting its motion, to render the pusher inoperative. When the pusher is so displaced, the tablets will be fed past the transfer station by the chain to a position in which they may be ploughed off the chain into a scrap box.

The invention provides, in combination with a pocketed conveyor chain arranged to convey articles to a transfer station, a pusher at the transfer station, mechanism for reciprocating the pusher transversely to the chain in timed relation to the forward movement thereof, to discharge the articles in succession from the pockets in the chain, a support for the pusher which is movable between a level at which the pusher is eifectiveto discharge articles from the chain and another level at which the pusher reciprocates idly, and manually controllable shifting mechanism for moving the support between its two alternative levels which includes means responsive to the position of the pusher in relation to the chain for rendering the shifting mechanism effective at those times only when the pusher can move up and down without obstruction by the chain or the articles carried thereon.

The shifting mechanism may comprise a member secured to the support and manually actuable means which is engageable with said member in alternative positions to efiect upward or downward movement of the support.

Preferably the support for the pusher is a continuously 2,934,196 Patented Ap 1 The lever is conveniently operable by means of a hand tion to actuate mechanism, e.g. a switch, for reducing the speed of a moulding device producing confectionery tablets carried by the chain, the chain and a wrapping machine to which the tablets are delivered by operation of the pusher.

One embodiment of the invention will now be described in detail with reference to the accompanying drawings in which:

Fig. 1 is a vertical section through the mechanism for controlling the lifting of the pusher,

Fig. 1A is a view looking in the direction of the arrow X in Fig. 1,

Fig. 1B is a section taken in a plane at right angles to that of Fig. 1,

Fig. 1C is a section on the line Y-Y in Fig. 1B,

Fig. 2 is a development of the cam utilised for raising and lowering the pusher,

Fig. 2A is a vertical section through the cam,

Fig. 3 is a side elevation of the pusher and associated mechanism and 'Fig. 3A is a corresponding plan view.

Referring first to Figs. 3 and 3A, it will be seen that tablets 30 are fed by a continuously travelling conveyor chain from a moulding device to a transfer station at which a reciprocating pusher 27 operates to transfer the tablets in succession from the pockets of the chain to p'ockets32 in an intermittently rotating feed disc 33 from which the tablets are transferred in succession to: a wrapping wheel as described in US. specification No. 2,784,541. The moulding device, the wrapping wheel and the elevator for transferring the tablets from the feed disc 33 to thewrapping wheel are of conventional construction and are accordingly not shown in the drawings. The speeds of operation of the various components of the complete machine, consisting of the moulding device, the chain and the wrapping mechanism, are of course properly co-ordinated. The complete machine is driven by an electric motor and runs at a normal high speed when a switch S, Fig. 1, is closed. When, however, the switch S is opened, the machine is caused to run at a slower speed.

The pusher 27, which normally occupies the level shown in full lines in Fig. 3, is reciprocated by an eccentric 34 on the upper end of a vertical shaft 15 carrying a gear wheel 13, held in contact with a thrust race 35 by a fixed fork 14 and driven by a gear wheel 36 on a driving shaft 37. The shaft 15 is splined to the gear wheel 13 so that it may move vertically, as later described, to lift the pusher 2.7 to the inoperative position shown in chain-dotted lines in Fig. 3. A cam operated lever 38 is coupled to the pusher 27 by a ball jointed link 39 and serves to impart to the pusher a. component of movement parallel to the length of the chain 31 as described in US. specification No. 2,784,541.

So long as the pusher 2.7 is at its operative level, the switch S is closed as described later, the machine runs at its higher speed and the tablets are fed in succession by the pusher 27 from the pockets of the chain 31 into the pockets 32 of the feed disc 33. When, however, the operator observes faulty tablets on the chain he is able,

as described later, by actuating a hand lever 1 (Fig. 1)

result the switch S is opened to cause the machine to run at its slower speed. a

The lever 1 is pivoted at 3 (Fig. IE) to a block 4 rotatably mounted on a shaft 7 and its movement is constrained by a gate 2 having therein a slot of the form shown in Fig. 1A. The lever is movable in the gate from a normal position D to a position C, which movement results in the plunger being liftedto its inoperative level, and on, via position B to a position A at which the machine is driven at reduced speed.

On the lever 1 is a block 6 carrying pegs 40, 41 for coaction respectively with a slot 50 in a lever secured to the shaft 7 and with a slot 90 in a cam piece 9 pivoted on a fixed stud 10.

When the lever 1 is in position A or B, or in any position between them, the peg 40 is disengaged from the slot in the lever 5, but when the lever 1 is shifted laterally into the limb of the gate containing position C, the peg 40 engages the slot 50 in the lever 5 and as the lever 1 is moved in this limb of the gate it is effective to rotate the shaft 7 through the agency of the lever 5.

When the lever 1 is in position A, the lever 5 which, as. stated, is uncoupled from the lever 1 is held by a spring 12 against a fixed stop 11 and the peg 41 engages the left-hand end of the slot 90 so holding the cam lever 9 clear of the switch S so that the switch S is open and the machine runs at a slow speed. The spring 12 maintains the shaft 7 in a position such that, as later described, the shaft 15 is lifted to hold the pusher 27 at its inoperative higher level. When the lever 1 is moved to position B, the peg 41 coacts with the slot 90 to depress the cam 9, thereby closing the switch S, as shown in Fig. 1, and causing the machine to revert to its normal fast speed. Movement of the lever 1 from position B to position C merely serves to couple the lever 1 to the lever 5. Movement of the lever 1 from position C to position D rocks the shaft 7 against the action of the spring 12 and causes the shaft 15 to be lowered to bring the pusher 27 to its operative lower level. When in position D, the lever 1 is slightly offset laterally from its position C so that it may be retained in a portion 2 of the gate. The slight lateral movement of the lever into this offset portion of the gate does not, however, disengage the peg 40 from the slot 50 in the lever 5. Movement of the lever 1 between positions B and D causes the pin 41 to travel in a concentric portion of the slot 90, so maintaining the switch S closed.

A lever 8 on the end of the shaft 7 is connected by a link 26 (Fig. 1A) to a bell crank 19 rotatable on a vertical pivot 42 'but incapable of moving vertically. The bell crank 19 carries cam followers 17, 18 situated at two different levels and capable of alternative cooperation, according to the position of the bell crank 19, with a cam 16 fixed to the shaft 15. The cam 16 has three

cam tracks

42, 43, 44 spaced by the same vertical distance as the followers 17 18. The centre cam track 42 extends continuously round the cam, while the; upper and

lower tracks

43, 44 are not continuous but run into the centre track as indicated at 45 and 46 in Fig. 2.

When the hand lever 1 is in position D, the lower follower 17 engages the centre cam track 42 and the upper follower 18 is spaced laterally from the cam, as shown in Fig. 1C. The shaft 15 is accordingly maintained in the lower position shown in Fig, 3, in which it is retained by engagement of a plunger 21 (Fig. 1B), loaded by a spring 22, against the upper edge of a collar on the shaft. The pusher 27 is accordingly operative. When, however, the hand lever 1 is moved to position C the bell crank 19 is rocked to withdraw the follower 17 from the centre cam track 42 and approach the follower 18 to the upper cam track 43. When the cam 16 is in a suitable angular position the follower 18 will enter the upper cam track 43, and, as the cam rotates, the follower 18 will travel down the portion 45 offthe cam track into the centre track 42, so raising. the: shaft. 15

4, to the position shown in chain-dotted lines in Fig. 3, in which it is retained by engagement of the spring plunger 21 beneath the collar 20 and in which the pusher 27 is inoperative. When the lever 1 is returned to position D, the bell crank 19 will be rocked to withdraw the follower 18 from the centre cam track 42 and introduce the follower 17 into the lower cam track 44. The follower 17 will then run up the section 46 of the cam track into the centre track 42 so lowering the shaft 15 to return the plunger 27 to the operative position.

Due to the special nature of the cam tracks, it is necessary to provide for deceleration of the moving parts at the end of their vertical travel caused by the cut-out sections 45, 46 of the tracks and for this purpose a double acting oil dashpot is incorporated in the mechanism. This is constituted by a piston 23, which is secured to the shaft 15 and is a free fit in a cylinder 24. Bleed holes 25 drilled through the cylinder walls communicate with the free oil in a reservoir 28, the holes being placed at the mid-position of the piston stroke so that the damping effect occurs only during the latter half of the stroke.

The cam 16 is, of course, so positioned on the shaft 15 that the rise and fall of the shaft takes place while the pusher 2'7 is in the correct part of its stroke.

Reference to Fig. 2 will show that the duration of the lift of the shaft 15 is twice that of the drop. This is rendered possible by the fact that the lift can start as soon as the tablet has been pushed into the feed disc 33 (i.e. when the pusher 27 is at its outer limit of stroke) and continue until the pusher starts to re-cross the path" of the chain in the direction towards the feed disc when it must be fully lifted. For the drop, however, owing to the possibility of there being tablets in the chain pockets passing under the lifted pusher, downward movement can only start after the pusher leaves the path of the chain on its return stroke, and must finish as the pusher re-enters the chain. Both lift and drop, therefore, finish at the same position in the stroke of the pusher.

What we claim as our invention and desire to secure by Letters Patent is:

1. The combination, with a pocket conveyor chain for conveying articles to a transfer station, of a pusher at the transfer station, mechanism for reciprocating the pusher transversely to the chain in timed relation to the forward movement thereof to discharge the articles in succession from the pockets in the chain, a support for the pusher which is movable between a level at which the pusher is effective to discharge articles from the chainand another level at which the pusher reciprocates idly and clear of the chain, a displacing member for moving said support to its alternative levels which is mounted on said support and movable with said pusher anda manually operable shifting member which is engageable with said displaceable member and effective to raise or lower said support at those periods only of the cycl'e'of reciprocation of the pusher when said pusher can change its level without fouling said chain and the articles carried thereby.

2. The combination, with a pocketed conveyor chain: for conveying articles to a transfer station, of a pusher at the transfer station, an upright rotating driving shaft constituting a support for the pusher, mechanism. driven. by the driving shaft for reciprocating the pusher transversely to the chain in timed relation to the forward rnovement thereof to discharge the articles in succession from the pockets in the chain, said driving shaft being:

movable between a level at which the pusher is effective to discharge articles from the chain and another levelat which the pusher reciprocates idly and clear of the chain, a cam secured to said driving shaft and formed withv alternative tracks, a pair of cam followers and'a manual control member coupled to said cam followers and. adapted to move them selectively into engagement with said cam tracks to move said driving shaft from one alternati've level to the other at times when the'pusher.

is unobstructed by said chain and the articles carried thereby.

3. Apparatus according to claim 2, wherein the cam has at difierent levels a continuous central cam track and upper and lower cam tracks spaced equally from the leading into the central cam track, the cam followers being spaced vertically by a distance equal to the vertical spacing of the cam tracks and being alternatively engageable with the upper and lower cam tracks to impart upward or downward movement to the cam and driving shaft as the case may be.

4. Apparatus according to claim 3, comprising a dashpot for decelerating the movement of the driving shaft as it nears the end of its upward or downward movement.

5. Apparatus according to claim 1, comprising a switch for controlling the speed of the chain and pusher, which is operable by said shifting member to reduce said speed by movement of said shifting member to a position beyond that corresponding to the inoperative level of the pusher.

6. Apparatus according to claim 2, wherein the manual control member is a pivoted lever movable in a gate and also shiftable laterally to connect and disconnect it from mechanism for imparting motion to the cam followers.

References Cited in the file of this patent UNITED STATES PATENTS 1,862,386 Nefi June 7, 1932 1,950,302 Hansen Mar. 6, 1934 2,567,041 Van Buren Sept. 4, 1951 2,652,137 Taronto Sept. 15, 1953 2,788,113 Curtis Apr. 9, 1957