US2676441A - Wrapping machine - Google Patents

Description

A ril 27, 1954 L. BROOK 1 2,676,441

WRAPPING MACHINE Filed April 21 4 Sheets-Sheet l 0 n 6 11) O o April 27, 1954 BROOK WRAPPING MACHINE 4 Sheets-Sheet 2 Filed April 21, 1952 April 27, 1954 L. BRQOK WRAPPING MACHINE 4 Sheets-Sheet 5 Filed April 21, 1952 April 27, 1954 L. BROOK WRAPPING MACHINE 4 Sheets-Sheet 4 Filed April 21, 1952 UNITED STATES NT OFFICE WRAEPIN G MACHINE Leonard Brook, Beeston,

to The Forgrove Mach Leeds, England, a com Leeds, England, assignor inery Company Limited, pany of Great Britain Application April 21, 1952, Serial No. 283,332

9 Claims. 1

This invention relates to wrapping machines of the type comprising a lifting plunger for lifting articles in succession into a wrapping mechanism, means for feeding a web of wrapping material across the path of the lifting plunger and a knife operating in timed relationship with the lifting plunger to sever a wrapper from the leading end of the web so that the wrapper will be carried with the article into the wrapping mechanism by the lifting plunger.

The most satisfactory control over the feed of the wrapper is obtained by using a picker to draw the web forward across the path of the lifting plunger, and a picker feed has long been used in machines organised for twist wrapping. Hitherto, however, in machines organised for bunch wrapping, the web of wrapper has been fed by feed rollers into a position beyond the knife and a suction head. or mechanical gripper device has been used for carrying the severed wrappers from the knife to position above the lifting plunger. The object of this invention is to provide a picker feed in a wrapping machine which, with minor modifications, can be converted from bunch wrap-- ping to twist wrapping and vice versa.

it is necessary to use a single picker, as if spaced pickers engaging opposite edges of the web of wrapper are used, one of these would foul the knife. The single picker must accordingly be di. feed. Diiferent requirements as to location of the picker are, however, imposed according as to whether the machine is to be used for bunch or twist wrapping.

In the case of bunch wrapping, the lifting plunger lifts the article and the wrapper on top of it through an orifice, usually lined with an annular brush, into the grippers of a rotary carrier head, the brush draping the wrapper about the article in the form of a cup, open at the lower end, and folding blades thereafter folding the de pending portion of the wrapper against the base of the article. For some articles (e. g. normal round and oval sweets) it is permissible and indeed preferred to use a forked lifting plunger and a centrally located picker which can move, on the forward stroke of the picker, through the gap between the limbs of the lifting plunger, which has not at that stage returned to the down position. in the case, however, of certain fragile or soft articles, for example soft centered chocolates, it is essential to support the whole area of the base of the article during its upward passage through the brush, so that a slotted lifting plunger cannot be used and the picker must be osed at or near the centre line of the wrapper y offset from the centre line of the wrapper feed sufficiently to clear the lifting plunger.

In the case of the twist wrapping, it is necessary to use, as described for example in U. S. specification No. 1,955,493, a lifting plunger having a pair of offset formers, one on each side of it, which support the ends of the tube into which the wrapper is folded around the article by lifting of the article into the grippers of the carrier head and subsequent action of folders to fold the depending wings of the wrapper against the base of the article, the pocket wheel thereafter carrying the article and wrapper to a station at which twist grippers engage and twist the projecting ends of the tube. In this case, an offset position of the picker cannot be tolerated. Firstly, this would involve spacing of the formers too far from the lifting plunger, and secondly the stretching of the wrapper by the offset picker prevents tidy formation of the ends of the tube. It is therefore necessary to use a forked lifting plunger and to dispose the picker in a central position.

According to the invention, therefore, I employ, in a wrapping machine of the above-described type, a reciprocating picker for drawing the leading end of the wrapper forward past the knife and over the lifting plunger, the picker being coupled to a cam-operated linkage, which imparts reciprocating movement to the picker and also serves to open and close it, and being laterally adjustable in relation to the linkage so that it may operate either centrally of the wrapper or at a position suniciently offset from the centre line of the wrapper feed to clear the lifting plunger.

Accordingly, when it is desired to convert the machine from bunch wrapping to twist wrapping the only modifications required in the wrapper feed mechanism are the substitution of the appropriate lifting plunger and. an adjustment of the picker in relation to the linkage operating it.

One embodiment of wrapping machine according to the invention for wrapping confectionery will now be described in detail, by way of example, with reference to the accompanying drawings, in which:

Fig. l is a side elevation of the machine,

Fig. 2 is a plan view, on a larger scale, of the wrapper feed table and associated mechanism,

Fig. 3 is a side elevation, also on a larger scale, of the picker actuating gear, the trip mechanism being omitted for clarity,

Fig. 4 is a corresponding end elevation,

Fig. 5 is a plan View, on a larger scale, of the picker actuating gear, and

Fig. 6 is a detail view, showing the picker shifted to its alternative and central position.

Like reference numerals indicate like parts in all the figures. These, except Fig. 6, show the machine organized for bunch wrapping. Fig. 6 shows how the picker is shifted in relation to its actuating gear when it is desired to use the machine for twist wrapping.

A web it] (Fig. 1) of heat sealing material (e. g. waxed paper) is periodically fed by a picker 29 (Fig. 2 from a reel H, over rollers i2, i3, and along an adjustable feed table M (Fig. 2) past a pair of cutting knives l5. These knives are periodically actuated in scissors fashion, as more fully described in U. S. application, Serial No. 282,139, to sever a wrapper from the leading edge of the web. The knives are caused to open by upward movement of an actuating member i5 (Fig. 1) against the action of a spring il', this movement being imparted to the member it by a cam-operated arm i8. Thereafter the member i6 descends, under the action of the spring ii, to allow the knives I5 to close and sever the web. A second reel EH of wrapper is provided for use when the reel H is exhausted.

The tablets to be wrapped are fed by hand from a hopper i9 (Fig. 1) into recesses 2! (Fig. 2) in a horizontal feed disc 22, disposed below the wrapper feed level, which is intermittently rotated in an anti-clockwise direction as seen in Fig. 2. As each recess 21 dwells beneath the out wrapper, a lifting plunger 23 (Fig. 2) rises to lift the tablet out of the recess, the plunger being actuated by a cam-operated arm 2 (Fig. 1) as described more fully in U. S. application Serial No. 283,333, and steadied by a link 25. As the tablet is lifted from the recess it carries the cut wrapper with it through an annular brush, or other folding device of known type contained in a member 25 (Fig. l) and into a pair of grippers ii on a carrier head 28, a cam-operated top plunger 25 having previously descended through the brush and serving to press the wrapper against the tablet during its transit through the brush and into the gripper jaws. The gripper jaws are cam operated and open to allow the article to enter them and thereafter close to grip the article prior to recession of the lifting and top plungers. A cam operated first folder (not shown) then moves across the base of the tablet to fold part of thedepending wrapper against it. The carrier head 28, which is intermittently rotated about a verticalaxis by a Geneva mechanism, then carries the tablet on to a heating station, the tablet moving across a fixed folder plate 39 which folds the remaining dependent portion of the wrapper against its base.

The remaining operations performed on the tablet are effected by a mechanism not shown in the drawings, but described in U. S. applica tions, Serial Nos. 283,334, now U. S. Patent No. 2,643,500, 284,995, now U. S. Patent 2,639,568 and 284,996. To complete the understanding of the operation of machine it may be briefly described as follows:

At the heating station, a heater is pressed against the base of the tablet to produce a heat seal between the pleats of wrapper folded against the base, and a top padder presses against the top of the tablet. At the next station to which the tablet is moved by the carrier head, a cool ing pad is pressed against the base of the tablet and a top padder against its top. At the next station a cooling pad is pressed against the base of the tablet. At the next and last station, the gripper jaws are opened by their cam and an 4 ejector ejects the wrapped and heat sealed tab let down a chute I00 (Fig. 1).

To convert the machine to twist wrapping, the lifting plunger is changed and the picker adjusted, as later described. The brush is removed, the gripper jaws on the carrier head are changed and the heater and cooling units are removed from the machine frame and replaced by a twist gripper assembly at what was previously the heating station. The twist grippers may be of the onstruction described in U. S. Patent N0. 1, 5 and may be built in position on the machine frame and coupled to or uncoupled from mechanism for driving them as and when required, and the heating and cooling units can be disconnected from the mechanism for driving them as an alternative to removal from the machine.

The picker 20 comprises, see Figs. 3-G, a fixed lower jaw SI, constituted by a forward extension of a bar 32, pivoted intermediately of its lengt by a pin 35 to a boss 4! on the upper end of an operating lever 34 and pivoted at its rear end, by a pin 38, to a boss lil on the upper end of a supporting link 35. The operating lever 34 is rocked to and fro, as later described, to impart more or less straight line reciprocating movement to the picker. The upper jaw 3'5 of the picker is attached, by a screw 45 and dowels w, to a rearwardly extending bar 39, pivoted on a pin to the bar 32 and by a pin 46 to the upper end of an operating link 42. A compression spring 2?, disposed between the bar 39 and a bracket 42 on the bar 32, tends to hold the jaws closed but the link 42 is movable downwardly, as later described, to open the jaws when required.

Distance pieces 29-, 149 are provided on the pivot pins 35, 38 which can be placed on one side or the other of the bosses M, id according as to whether it is desired to locate the picker at the centre line AA of the wrapper feed or in an ofiset position. Figs. 3, 4 and 5 show the picker located in an offset position, and Fig. 6 shows the distance pieces shifted to the opposite side of the bosses to locate the picker at the centre line of the wrapper feed.

The lower end of the link 42 is coupled by a pin 99 to a lever 'H for actuating the link 42, the combined thicknesses of the lever H and the link :12 being equal to the width of the distance pieces es, hi9. When the .picker is in its offset position, the link '22 is located behind the lever if as shown in Figs. 3 and 4. When the picker is set to its central position, the pin 96 is removed and the lower end of the link 22 shifted to the front of the lever H.

The adjustment of the picker from the offset to the central position or vice verse is thus a very simple matter, it being necessary only to remove the pins 35, 38 and 95 and to alter the position of the distance pieces 49, I69 and of the lower end of the link 42.

A picker-reciprocating cam 55] periodically rocks a rocking shaft 5|, through the agency of a follower 52 on an arm 53 attached to the shaft 5|, and this shaft carries a driving lever 54 formed with a slot 55. The operating lever 34 is pivotally mounted on a shaft 55, on which is also pivoted a bell crank 51. The lower arm of the bell crank is slotted, and a slide block 58, engaging in the slots in this arm and in the driving lever 55, serves to impart oscillating movement to the bell crank 51, the stroke being adjustable by altering, by means of an adjusting screw 59, the position of the slide block 58 in the slots. A pointer on the slide block 58 cooperates with a scale 6| on the driving lever 54 to facilitate adjustment of the slide block 58 and therefore the stroke which will be given by the bell crank 51, as later described, to the picker 20 and accordingly the length of the wrapper fed forward at each machine cycle.

A spring 53, mounted in compression between the upper arm of the bell crank and the operating lever 35 serves to move the operating lever and the picker on the forward stroke, during which it rocks anti-clockwise about the shaft 56. while there is a positive return stroke imparted by cooperating abutments E 5, 65 on the bell crank 51 and operating lever 34 respectively, the abutmerit 65 being constituted by an adjustable screw. There is a possibility of the picker jamming on the forward stroke, as for example if a tablet should fall off the lifting plunger, and in this event the compression spring 63 will yield to prevent damage to the mechanism.

Opening and closing movement of the picker jaws is effected by a picker opening cam (not shown) which coacts with a follower on an arm fixed to a rocking shaft 5 5 (Fig. 1). This carries a pair of arms one, E1, of which is connected by a link (it to an arm 59 on a shaft 10, to which is fixed the lever ii coupled to the link 42 for actuating the movable picker jaw 31. The other arm E2 on the rocking shaft 66 is connected by a push rod T3 to a clamp is for clamping the web of wrapper behind the knives. A spring (not shown) normally holds the clamp in the off position.

It is necessary to interrupt the wrapper feed in case the recess in the feed disc about to reach the lifting station contains no tablet. Accordingly a feeler finger, carried by a member 15, is moved, by spring action, from a trip cam it (Fig. 4) into the recess dwelling in the station immediately prior to the lifting station. If this recess is filled, the finger is arrested and the trip mechanism is ineffective. This portion of the mechanism, being known per se, is not illustrated in the drawings. If, however, there is no tablet in the recess, the finger can move further, thereby causing displacement of a spring loaded and normally inoperative catch ll into position to act with a knife edge 18 on the lever 1!. When the catch l? is in position, the link 42 is unable to move up to close the jaws 37, 3|. The jaws consequently fail to close at the end of the forward stroke of the picker, and the following return stroke is an idle one.

A wrapper dipping cam 19 (Fig. 4) coacts with a follower 8%) on an arm 8! carried by a rocking shaft 82 to which is fixed a wrapper dipping lever This is connected by an adjustable pin and slot connection 84, B5 and a link 86 to a wrapper dip-ping arm 8i, mounted on a fixed pivot 83, and pivoted to the lower end of the supporting link 36 for the rear end of the bar 32. At the end of the return stroke of the picker the cam 18 operates to raise the supporting link 36, by an amount determined by the adjustment of the pin and slot connection 84, 85, thereby dipping the picker 2c, and the wrapper carried by it, towards the lifting plunger.

The cycle of operations of the picker is as follows:

After the picker 2!; has moved into its extreme forward position, the picker jaws 31, at close to grip the leading edge of the wrapper which lies on the cutting line of the knives 15. This grip is maintained by the compression spring 4? and continued movement of the rocking shaft 66 actuated by the picker opening cam thereafter cause the clamp 14 to lift. The picker now makes its return stroke to feed the wrapper into position above the lifting plunger 23. The clamp 54 then descends on the web, the levers ll-J2 making a partial movement insumcient to open the picker jaws. The knives I5 then operate. The severed wrapper is then carried by the picker a short distance (e. g. T e") away from the knives and at the same time the wrapper dipping cam 79 lowers the wrapper towards the feed disc. The picker jaws open at the moment when the wrapper is trapped between the ascending tablet and the top plunger 29 and the picker quickly retires sufficiently (e. g. 7 /2") to allow of free upward movement of the wrapper. The picker then moves forward in one movement to its forward position between the knives, the wrapper dipping cam '19 returning the picker to its original level during this forward stroke. The forward stroke occurs while the tablet is being lifted by the lifting plunger.

The tablets in the recesses in the feed disc may be swept by the feed disc along a stationary plate which supports the tablets on their way to the lifting plunger and in this case a solid lifting plunger may be used for bunch wrapping. The picker must then be offset. Alternatively, the tablets may be supported by an annulus beneath the recess as described in U. S. specification No. 1,955,493. In this case a bifurcated lifting plunger must be used, and the picker can conveniently be on the centre line. Where the tablets are not sticky and have reasonably fiat bases, I prefer to use the first method, as the machine is easier to feed at high speed by hand when without an annular support in the feed disc. Where, however, conditions are bad and the tablets are sticky, and particularly if the tablets have bulbous bases, an annular support is necessary.

What I claim as my invention and desire to secure by Letters Patent is:

1. In a wrapping machine comprising a wrapping mechanism, a lifting plunger for lifting articles in succession into said wrapping mechanism, a reciprocating picker for feeding a web of wrapping material across the path of the lifting plunger, said picker comprising a bar, a fixed jaw on said bar and a movable jaw pivoted to said bar, and a knife operating in timed relationship with said lifting plunger and picker to sever at each stroke of said lifting plunger a wrapper from the leading end of said web, the combination with said picker of an operating lever, a supporting link, pivot pins connecting the ends of said operating lever and supporting link to said bar, a removable distance piece on each pivot pin, said distance pieces being mountable on said pins on one side or the other of said bar to locate the bar in alternative positions, in one of which the picker is presented centrally to the wrapper and in the other of which the picker is sufficiently offset from the center line of the wrapper to clear the lifting plunger, and a cam operatively connected to said operating lever for imparting reciprocating movement to said bar.

2. In a wrapping machine, a combination as claimed in claim 1, comprising an actuating lever, an operating link pivoted at one end to the movable jaw of the picker, a detachable pivot pin connecting the other end of the operating linktotheactuating lever, said operatinglink being shiftable in relation to said pin to move it to one or the other side of said actuating lever to conform with the central and offset positions respectively of the picker, and a second cam for imparting oscillating movement to said actuating lever and thereby, through said operating link, opening and closing said movable jaw.

3. In a wrapping machine, a combination as claimed in claim 1, comprising a shaft constituting a pivot for the operating lever, a bell crank pivoted on said shaft and linked to said earn, a spring coupling said bell crank to said operating lever and serving to drive said operating lever on the forward stroke of the picker, and cooperating abutments on said bell crank and operating lever for imparting a positive return stroke to the picker.

4. In a wrapping machine, a combination as claimed in claim 1, comprising a shaft constituting a pivot for the operating lever, a bell crank pivoted on said shaft, said bell crank having a slotted arm, a slotted driving lever linked to said cam, a block adjustable in the slots in said driving lever and bell crank for imparting movement to the bell crank from the cam, a spring interposed between the other arm of the bell crank and the operating lever and serving to drive said operating lever on the forward stroke of the picker, and cooperating abutments on said bell crank and operating lever for imparting a positive return stroke to the picker.

5. In a wrapping machine, a combination as claimed in claim 1, comprising an actuating lever, an operating link pivoted at one end to the movable jaw of the picker, a detachable pivot pin connecting the other end of the operating link to the actuating lever, said operating link being shiftable in relation to said pin to move it to one or the other side of said actuating lever to conform with the central and offset positions respectively of the picker, a clamp coupled to said operating link and operable thereby to clamp the web of wrapper behind said knife during operation of said knife, and a second cam for imparting oscillating movement to said actuating lever and thereby, through said operating link, opening and closing said movable jaw.

6. In a wrappin machine comprisin a wrapping mechanism, a lifting plunger for lifting articles in succession into said wrapping mechanism, a reciprocating picker for feeding a web of wrapping material across the path of the liftin plunger, said picker comprising a bar, a fixed jaw on said bar and a movable jaw pivoted to said bar, and a knife operating in timed relationship with said lifting plunger and picker to sever at each stroke of said lifting plunger a wrapper from the leading end of said web, the combination with said picker of a linkage for imparting reciprocatin movement to said bar, a first cam for actuating said linkage to reciprocate said bar, a spring urging the movable jaw of the picker to closed position, an actuating lever, an operating link connecting said actuating lever and said movable jaw, a second cam for oscillating said actuating lever to open and close the picker, an intermittently moving recessed feed disc for feeding articles in succession into position above the lifting plunger, means for testing the presence of an article in the recesses in said disc as they move into position above the lifting plunger, and a catch controlled by said testing means and operable thereby, when absence of an article in a recess is detested, to interrupt movement of said actuating lever and thereby to prevent closing of said movable jaw.

7. In a wrapping machine comprisin a wrapping mechanism, a lifting plunger for lifting articles in succession into said wrapping mechanism, a reciprocating picker for feeding a web of wrappin material across the path of the lifting plunger, said picker comprising a bar, a fixed jaw on said bar and a movable jaw pivoted to said bar, and a knife operating in timed relationship with said lifting plunger and picker to sever at each stroke of said lifting plunger a wrapper from the leading end of said web, the combination with said picker of an operating lever and a supporting link both pivoted to said bar, a first cam for actuatin said operating lever, to reciprocate said bar, a spring urging the movable jaw of the picker to closed position, an actuating lever, an operating link connecting said actuating lever and said movable jaw, a second cam for oscillating said actuating lever to open and close the picker, a wrapper dipping cam, and a linkage connecting said wrap-per dripping cam to said supporting link for rocking said bar, during the return stroke of the picker, about its connection to said operating lever and thereby lowering the wrapper towards the liftin plunger.

8. In a wrappin machine comprising a wrapping mechanism, a plunger for moving articles in succession into said wrappin mechanism, a reciprccat"g picker for feeding a web of wrapping material across the path of the plunger and a knife operating in timed relationship with said lifting and picker to sever at each stroke of said plunger a wrapper from the leading end of said web, the combination with said picker of an operating lever, a pivot pin connecting said operating lever to said picker, a removable distance piece on said pivot pin, said distance piece being mountable on said pivot pin on opposite sides of said picker to locate said picker in two alternative positions, in one of which the picker is presented centrally to the V wrapper and in the other of which the picker is sufficiently offset from the center line of the wrapper to clear the plunger, and a cam operatively connected to said operating lever for imparting reciprocatin movement to said picker.

9. In a wrapping machine comprising a wrappin mechanism, a plunger for moving articles in succession into said wrapping mechanism, a reciprocatin picker for feeding a web of wrapping material acr ss the path of the plunger and a knife operating in timed relationship with said lifting plunger and picker to sever at each stroke of said plunger a wrapper from the leading end of said web, the combination with said picker of an operating lover, a pivot pin connecting said operating lever to said picker, a removable distance piece on said pivot pin, said distance piece bein mountable on said pivot pin on opposite sides of said picker to locate said picker in two alternative positions, in one of which the picker is presented centrally to the wrapper and in the other of which the picker is sulficiently offset from. the center line of the wrapper to clear the plunger, a movable jaw on said picker, an operating link pivoted at one end to the movable jaw of the picker, an actuating lever, a detachable pivot pin connecting the other end of the operating link to the actuating lever, said operating link being shiftable in relation to said pin to move it to one or the other side of said actuating lever to conform with the central and offset positions respectively of the picker, a first cam operatively connected to said operating lever for imparting reciprocating movement to said picker and a second cam for imparting osci11ating movement to said actuating lever and thereby, through said operating link, opening and closing said movable jaw.

N me Date Number a Berger Feb. 20, 1900 Number 10 Name Date Igou July 20, 1915 Harrold Dec. 8, 1925 Jones Sept. 6, 1927 Grover Apr. 17, 1984 Jagenberg July 14, 1936 Eckhard Sept. 20, 1938 Rose Nov. 22, 1938 Banthin May 23, 195

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