US2875567A

US2875567A - Wrapping machines

Info

Publication number: US2875567A
Application number: US761251A
Authority: US
Inventors: Brook Leonard; Walker Rowland
Original assignee: Forgrove Machinery Co Ltd
Current assignee: Forgrove Machinery Co Ltd
Priority date: 1957-09-25
Filing date: 1958-09-15
Publication date: 1959-03-03
Anticipated expiration: 1976-03-03

Description

L. BROOK ET AL 5 Sheets-Sheet 1 Filed Sept. 15, 1958 ky/a md 2? Mia March 3, 1959 L. BRdoK ET AL WRAPPING MACHINES 5 SheetsSheet 3 Filed Sept. 15, 1958 March 3, 1959 Filed Se t. 15, 1958 BROOK ET AL 2,875,567

WRAPPING MACHINES 5 Sheets-Sheet 4 I March 3, 1959 1.. BROOK ET AL 2,875,567

WRAPPING MACHINES Filed Sept. 15, 1958 5 Sheets-Sheet 5 United States PatentO WRAPPING MACHINES Leonard Brook, Leeds, and Rowland .WfllkmgQDeWsblllfY,

England assignors to The FOlgl'OYEjMiiCllllll'Y C m "pany Limite'rL-Leeds, England, a company of-Great Britain Application September 15, 1958, SerialNo.;7 61,251

Claims priority, application Great Britain September 25, 1957 .9 Claims. (Cl. 53-9370) This invention relates to twist wrapping machines. In

in'toposition between the, twister units their jawsjclo se on the projecting ends of the wrapper and the twister units .move inwards towards the article as the V rotating ,jaws twist theends ofthe wrapper, theiaWs opening,

when sufficient twist has, been imparted, to allow the wrapped article to be moved onlby thegcarrierhead, ,wlijereupon the twisterunits move outwardlyagain to their o'riginal pos-itions.

iIn existing twist wrapping machines two identical twis ter units are used. This involvesa duplication of operating parts, the twister units require individu al adjustment, andeach twister unit requires fairly large .and

cornplicated, supporting members. Also, one of the twister units is usually so positioned as to cause conges- ..t. o .a no -a l t i respect t .q hsrim ortam sections of the wrapping machine. The object ofthe invention is to eliminate these disadvantages. .The inyention accordingly provides a .twist wrapping machine having two dissimilar twisting units, one being a large m ste in cs r ins the Wh s thi mss sn f or adjusting the stroke and initialpositionsofthe barrels of both units and Jthe other being a small slave unit driven from the master 'unit andarranged to reproduce exactly the movments of the barrel and jaws thereof.

it flQn'e specific embodiment of the invention will now be described indetail, by way of example,with reference to the accompanying drawings, in which:

l is adiagramrnatic frontelevation of part of a Wrapping machine embodying twister units in accordance with theinvention,

FigQ2 is a side elevationpartly in section, showing the twister units,

Fig. 4 is a sectionon theline IV-IV of FigrZ,

Fig. 5 is a plan view of the n as ter twister unit,

Fig. 6 is a detail sectional view showing part of the master twister unit, and

Fig. 7 is a section on the line VII-VII in Fig. 6.

Like reference numerals indicate like parts throughout the figures.

Fig. 1 shows an intermittently rotating carrier head 10 by means of which articles are fed in succession from a loading station A to a twisting station B and thence to a discharge station C. The carrier head 10 is of conventional construction and comprises four pairs of jaws 11, linked by springs 12. The jaws carry meshing gear sectors 13 and are controlled in conventional fashion, by a cam not shown, so that they are opened at the loading station A to receive a partially wrapped article, then closed upon the article to retain it during an end view lookingfromthe right hand sid e k nives 21. top plunger 22, lifts an article into the jaws 11 of the carrier head thewrapper is folded about the article in 2,875,567} P te ted Ma 3, .19

r in ice inverted U-formation. Afterthe jaws 11 have closed on the article .a movable folder 23 folds one of the, depending wings of the wrapper against the base of the article. During subsequent travel of the article to the twisting stationB, a fixed folder 24 folds the other depending wing of the wrapper against the base of the article. At the twisting station B the projecting ends of the wrapper are twisted by the mechanism shown in Figs, 2-7. The articles are finallyejected from the carrier head at the discharge station C as already indicated.

The twisting mechanism includes a large master twister unit ZS and a small slave twister unit'26. The master twister unit includes a barrel 27 carrying a pair of .twister jaws 28 and the slave twister unit includes a barrel 29 carrying a pair of twister jaws 30. As will be appreciated the barrels of the two twister units require to be rotated and also. to be reciprocated towards and away from the article at the twisting station. Furthermore, each pair of twister jaws requires to be moved from an open position, shown in chainedotted lines in Fig. 2, to a closed position in which it may engage and twist the .end of the wrapper31 (Fig. 2).

The barrel 27. of the master unit carries a pinion 32 meshing with a gear 33 on a cam shaft 34 and maintained in constant rotation bya driving gear 35. Rotary movement is imparted to the barrel 29 of the slave unit througha shaft 36, carrying atone end a gear 37, driven from the gear 33,by compound gears 38, 3 9. At the other end, the shaft 36. carries a gear 40 meshing with a gear 41 on the barrel 29. The gears: 32 and 39 are .pair of adjusting levers. .One of the adjusting levers is v a bell crank, 47,. 47a rotatable about a fixed pivot 48 and carrying a follower/t9 coacting with the cam .46 and. a block 50 (Fig.7) engaging a slot 51 in the portion 47a of the bell crank. Attached to the block 50 by a pin 52 nether block 53 engaging a slot 54 in the other adjust- .m j le r whic is rotata ly m nt dcn h o kin shaft 43. A screw 5j6jin theportion of the bell crank engages a threaded hole inthe blockSti and is adjustable by a knob 57 to vary the positions of the

blocks

50, 53 in their

slots

51, 54 and thereby the stroke imparted to the lever 55 by the cam 46. The lever 55 carries a worm 58 engaging a worm sector 59 on a lever 60 fixed to the rocking shaft 43. The worm 58 is ro-. tatable by a knob 61 on the lever 55 to adjust the position of the rocking shaft 43 with respect to the lever 55 and thereby the initial setting of the barrel 27 of the master unit in relation to the article to suit variations in the length of the article to be wrapped. Adjustment of the knob 57 serves to vary the extent of reciprocation of the barrel 27 of the master unit. A scale 62 (Fig. 2)

games? and pointer 63 serve to indicate the initial setting of the barrel 27 of the master unit.

The barrel 29 of the slave unit receives reciprocating movement from the rocking shaft 43 by the following mechanism, which ensures that the adjustments made by the

knobs

57, 60 are effective also on the barrel 29 of the slave unit. A toothed quadrant 64 (Fig. 2) fixed to the rocking shaft 43 meshes with a toothed quadrant 65 freely mounted on the shaft 48 and carrying an integral arm 67 engaging a clamp block 68 fixed to a tube 69 surrounding the cross shaft 36 and fixed to the repeater head 70 of the slave twister unit. The cam 46 accordingly imparts reciprocating movement to the barrel 29 of the slave unit through the agency of the arm 67 and the tube 69.

The jaws 28 of the master unit carry gear segments 71 engaging a rack 72 which is slidable in the barrel 27 and normally held by a spring 73 in position to close the jaws. The jaws 28 are periodically opened by a cam 74 on the cam shaft 34, which cooperates with a follower 75 on a lever 76, pivoted on a fixed bracket 77 and coupled by a link 78 to a lever 79 pivoted at 80 to the control lever 42. The lever 79 carries a tappet 81 which bears on the end of the rack 72. The pivot point of the link 78 on lever 80 is near the rocking shaft 43 so that movement of the control lever 42 to reciprocate the bar- .rel 27 of the master unit has little or no effect on the position of the lever 79 in relation to the jaw-actuating rack 72.

The jaws 30 of the slave unit carry gear segments 82 engaging a rack 83, normally urged by a spring 84 in the direction to close the jaws 30. The end of the rack 83 abuts against a tappet 85 carried by a cam lever 86, pivoted at 87 to the head 70 and carrying a follower 88 cooperating with a cam 89 on the remote end of the cross shaft 36. The cross shaft 36 partakes of the reciprocation of the tube 69.

Due to the small size of the slave unit 26, it will not interfere seriously with access to other parts of the wrapping machine.

The sequence of operation of the above mechanism is as follows:

The intermittently rotating carrier head carries the partially wrapped article, on arrival thereof at station B,

into position between the continuously rotating twister jaws 28, 30, the jaws being fully open and retracted to allow the tubular projecting ends of the wrapper to pass between them and into the twisting position.

The carrier head comes to rest and the jaws 28, 30 close on the wrapper tails and commence twisting as shown in Fig. 2. During the twisting operation the jaws 28, 30 move inwards a pre-determined distance to prevent the wrapper from being torn due to the stress in the wrapper produced by the rather violent twisting action.

' This inward movement of the jaws 28, 30 is provided by the master twister barrel 27 on the one side and the repeater head 70 on the other and may be varied as previously described to suit the texture of the wrapper being used.

After the desired amount of twist has been imparted the jaws 28, 30 open and allow the article, which is now completely wrapped, to be carried clear by the carrier head and finally discharged therefrom.

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

1. A twist wrapping machine comprising two dissimilar twisting units each comprising a barrel mounted for reciprocation and rotation therein and carrying a pair of jaws for engaging and twisting the projecting ends of a wrapper on an article to be wrapped, one of the units being a large master unit incorporating the whole of the mechanism for adjusting the stroke and initial positions of the barrels of both units and the other unit being a small slave unit driven from the master unit nd arranged to reproduce exactly the movements of the barrel and jaws thereof.

2. A wrapping machine according to claim l, wherein the slave unit has a reciprocating repeater head carrying gearing transmitting rotation to its barrel from a cross shaft connecting the two units and geared to the barrel of the master unit.

' 3. A wrapping machine according to claim 2, wherein the master unit includes a rocking shaft, a cam for imparting rocking movement to the rocking shaft through an adjustable linkage and a lever on the rocking shaft "for imparting reciprocating movement to the barrel of the master unit, and comprising means actuated by the rocking shaft for imparting reciprocating movement to the repeater head of the slave unit.

4. A wrapping machine according to claim 3, wherein the repeater head is connected to a hollow shaft surrounding the cross shaft and coupled to the rocking shaft in the masterunitfso as to be reciprocated thereby.

' 5. A wrapping machine according to claim 3, wherein theadj'ustable linkage comprises a first lever arranged to be rocked by the cam, a second lever coupled to the rocking shaft, and a coupling between the two levers which is adjustable to vary the stroke imparted by the first to the second lever.

6. A wrapping machine according to claim 5, wherein the levers carry blocks connected together and mounted to slide in slots in the levers, and comprising a screw for adjusting the positions of the blocks in the slots and thereby the stroke imparted by the first to the second lever. v

7. A wrapping machine according to claim 5, wherein the second lever is rotatably mounted on the rocking shaft and adjustably coupled to a third lever fixed to the rocking shaft by means permitting of adjustment of the relative angular positions of said levers.

8. A wrapping machine according to claim 7, wherein the second lever carries a worm engaging a toothed segment on the third lever and an adjusting knob for rotating the worm.

9. Awrapping machine according to claim 2, wherein the jaws of both twisting units carry toothed segments engaging racks mounted to reciprocate in their respective barrels, and comprising a cam and cam lever in the master unit for periodically actuating its rack to open and close its jaws and a cam on the cross shaft coacting with the rack of the slave unit through a cam lever mounted on the repeater head of the slave unit.

No references cited.