US2813387A - Wrapping machines - Google Patents

Description

A. HOPTN WRAPPING MACHINES New. 19, 1957 3 Sheets-Sheet l Filed may 11,A 1956- HNVENTOR v LAN H ovToN MemQ/m ATTORNEYS Nov. 19, 1957 A, HoF-TON WRAPPING MACHINES v3 Sheets-Sheet 2 Filed-May 11, 1956 im VENT-on HLHN HPToN ,MMM/@ww MTTvRA/EYS Nov. 19,1957 A. HoPToN 2,813,387

` WRAPPNG MACHINES Filed May 11. 195s s sheets-Sheet s mvENToR AL N H @P7-m ATranmsw/s 2,813,387 WRAPPING MACHINES Alan Hopton, Stourton, Leeds, England, assignor to The Forgrove Machinery Company Limited, Leeds, England, a British company Application May 11, 1956, Serial No. 584,380

Claims priority, application Great Britain February 23, 1956 V3 Claims. (Cl. 53-229) This invention relates to a wrapping machine for wraping stacks of loose biscuits, or other thin articles of similar shape, of the type comprising an intermittently moving wrapping wheel, mounted to rotate on a horizontal axis, for transporting the stacks of biscuits in succession, each with a Wrapper folded in U formation about it, from a loading station to a folding station, a rotary folder at the folding station mounted for rotation about an axis parallel to that of the wrapping wheel, an oscillating tucker blade for pressing into a cleft in the rotary folder the projecting wings of the wrapper associated with each stack of biscuits arriving at the folding station, thereby forming the first portion of a double fold, and means for rotating the rotary folder, after withdrawal of the tucker blade from the cleft, in relation to the stationary biscuits to form the second portion of the double fold, the rotation of the rotary folder moving the same from its receiving position to a discharge position in which it permits of withdrawal of the double fold from the cleft on continued rotation of the wrapping wheel.

This mechanism, which is described in United States Patent No. 2,612,740, and more fully in U. S. Patent No. 2,672,717, has been found effective to form the double fold in the wrapper when the wrapper is a relatively thin single Wrapper of a material such as a heat sealing cellulose iilm. Recently, however, thicker wrapping materials have come into common use, for example laminated materials of various kinds and also double wrappers, e. g. of cellulose iilm and vegetable parchment. These less pliable wrapping materials, or combinations of wrapping materials, tend to offer high resistance to insertion into the cleft in the rotary folder by the oscillating tucker blade if the cleft in the rotary folder is made too narrow, `while if the cleft is made wider to reduce this resistance the wrapping material is not sufficiently well creased to form a good double fold.

According to the present invention, the cleft in the rotary folder of a wrapping machine of the above type is defined by a pair of relatively movable jaws which define 'a relatively wide cleft when the rotary folder is in its receiving position and cam operated mechanism is provided which serves, as a rotary folder moves from its receiving to its discharge position, rst to approach the jaws so as positively to crease the double fold in the `Wrapping material, and thereafter to open the jaws again. ,In this way, the cleft can be made sufficiently wide to ensure that the Wrapping material will be effectively inserted into the cleft by the oscillating tucker blade and also suliciently wide, when the rotary folder is in its discharge position, to allow of easy withdrawal of the double fold, While at the same time the wrapping material will be effectively creased during movement of the rotary folder from its receiving to its discharge position to form a good double fold.

In the machine described in United States Patent No. 2,612,740 the stacks of biscuits are carried by the wrapping wheel from the folding station to a pressing station and 2,813,387 Patented Nov. 19, 1957 thence to a discharge station. At the pressing station a presser presses the double fold and, in the case of a Wrapper of heat sealing material, the presser is constituted by a heat sealing member which forms a heat seal on the package at the double fold. I have found that with the thicker wrapping materials, or combinations of wrapping materials, the heat sealing member does not dwell in contact with the package for long enough to transmit the heat through the folded thicknesses of wrapping material and so seal the double fold down on to the package itself.

According to the present invention, this difficulty is circumvented by embedding heating elements in or attaching them to lone or both jaws of the rotary folder. These heating elements are` preferably electrical. When thick or multiply heat sealing wrappers are used, the heating element or elements associated with the rotary folder may be switched on, with the result that, owing to the preheating of the double fold by the rotary folder, there Will be considerable residual heat in the double fold by the time it reaches the pressing station, and this ensures that the additional heat applied by the heat sealing member at that station will securely seal the double fold to the package. When non-heat-sealing wrapping materials, e. g. vegetable parchment, are being handled the heating elements at the folding station and at the pressing station may be switched olf.

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

Fig. 1 is a front elevation of part of the machine, with the Wrapping wheel removed, showing the mechanism for forming the double fold,

Fig. 2 is a section on the line II-II in Fig. l,

Figs. 3-5 are detail views on a large scale, showing successive positions assumed by the mechanism for forming the double fold, and

Fig. 6 is a view, on a still larger scale, showing the jaws of the rotary folder.

Like reference numerals designate like parts throughout the figures.

The machine illustrated in the drawings is, in principle, similar to that described in United States Patent No. 2,672,717. It includes a wrapping wheel 10 (Figs. 3-5) xed to a horizontal shaft which is given an intermittent motion by means of a Geneva mechanism, turning through at each step. The wrapping wheel has four holding pockets, each constituted by a fixed jaw 11, a movable jaw 12 spring-pressed towards the fixed jaw, and a pair of tuckers (not shown) for gripping the end biscuits of a stack of biscuits contained within the pocket. The iutermittent movement of the wrapping Wheel moves the stacks of biscuits in succession from a loading station to a folding station, then to a pressing station and finally to a discharge station.

The stacks of biscuits (one of which is indicated at 13 in Figs. 3-5) are lifted in `succession into the pockets at the bottom position of the wrapping wheel, which constitutes the loading station, a wrapper (shown at 14 in Figs. 35) being fed, by any suitable wrapper feed mechanism, into position between the lifter and the wrapping wheel at each cycle of operation of the lifter, so that the wrapper is carried by the article into the pocket and thereby folded in U-formation about the article.

The wrapping wheel then rotates through 90 to bring the stack of biscuits to the folding station. Here, as indicated in Fig. 3, the upper projecting wing 15 of the wrapper comes into contact with a rotary folder 16 (see also Fig. l) constituted by a pair of jaws 17, 18 forming a cleft 19 between them.

The jaw 17, which is of angle section, is fixed by bolts 3 r (Fig. 2) to a carrier 21 attached to a shaft 22 carrying a gear wheel 23 (Fig. l) by which rotary motion is imparted to the folder as later described. The other jaw 18, which is of triangular shape, is `hinged by .a pin .24 and to the jaw 17 carries afollower 25 (Figs. 3-5) which coacts with a track 26 in a fixed .cam 27.

On arrival of an article .at .thefolding station, the cleft 19 in .the vrotary folder is open .as shown in Fig. 3. .An oscillating tucker .blade 28 is then moved 4from the position shown in Fig. l to that .of Fig. 3 to force .the `projecting wings of wrapper yinto the cleft, .as shown in Fig. 3, to form the .first part of a double foldinthe wrapper, and thereafter .returns to the .position Vof Fig. .1. The tucker blade 2'8 is actuated by a cam 29 (Fig. l) on the cam shaft 4l) through .the agency of .a .follower .30, a bell crank 31, a link .32 and .an .arm .3.3 .fixed vto a shaft 34 carrying the `tucker blade.

r-llhe .gear wheel .23 for rotating .the .rotary folder meshes with a .gear wheel 35 coupled by .alink 3.6 to a bell crank 37 carrying a .follower 38 coacting with acam 39cm the cam shaft 40. After the tucker .blade 28 has w-ithdrawn from the -cleft .19 in the rotary folder., the cam 39 actuates the gear wheel 35 .-torotate the folder 16 from the .receiving position shown .in `Fig. .3., fin which the cleft 19 yfaces downwardly, to a discharge position, shown in Fig. 5, in which the cleft faces tupwardly, this action forming the second `part of the :double fold. As the rotary folder moves vfrom the position of lFig. 3 to .that of Fig. 5, the follower first presses the movable jaw 18 .against the fixed jaw 17, as shown in Fig. 4, to crease the double fold in the wrapping .material .and .thereafter moves the jaw 18 away from `the jaw 17 so that, .by ythe vtime .the

yrotary folder reaches the .discharge yposition (Fig. 5) Athe cleft 19 is again open to permit of easy withdrawal .of the double fold from the rotary folder `as the result of continued rotation of the wrapping wheel.

As the rotary folder moves into the rdischarge .position a fold retaining blade 41 ismoved into ,position,as shown in Fig. 5, to press .the .doublefold 42 against the package as it is pulled out of the .cleft .19 in `the .rotary folder. The retaining blade 41 is mounted .onanarm 43 pivoted to the wrapping wheel shaft 44 (Fig. .1.) .and .coupled to the rotary folder by an eccentric 145 fixed .to the .rotary folder, a link 46 embracing -the .eccentric .and a pin `47. This coupling, as already stated, brings the retaining blade 41 into the `operative positionshown .in Pig. .5, when the rotary folder T6 is rotated 'into .the .discharge position, and .returns the retaining 'blade 41 .into inoperative vposition when the rotary folder v1.6 is -afterwards Aturned back into its initial receiving .position (Fig. 3) thisaction taking place after the wrapper has been withdrawn `from the rotary folder.

An arcuate yplate 48 extends around the wrapping wheel between .the folding station and the pressing station `and maintains .the double fold pressed l.against `the package. Here a heated sealing member 49 is .caused to descend on the double fold. This heat sealing member, which is moved from the ejector mechanism which will Ashortly be described, presses resiliently on the double foldand forms a heat seal inthe 7package at vthat point. Where a nonheating sealing wrapping material is used, e. :g. parchment paper, .the heat sealing member .is not heated and serves merely to Ipress the double fold. The effect of heat sealing the double 'foldis to lock the wrappersecurely tothe package, so that lit cannot corne olf .except if it Vbe torn. An electrical heater 50 fis inserted into the fixed jaw 17 of the rotary folder as `shown .in Fig. 6 for the purpose of preheating the double fold at the folding station. The heater is, of course, switched off when nonheat-sealing wrapping materials are being handled. The .heater may, alternatively or in addition, be fitted at 71 to the movable jaw 18 of the double folder. Alternatively, heaters may be fitted to both jaws of the double folder. Again the ,heater or heaters may be embedded in the jaw or jaws of the double folder.

The nent step 'of movement of the wrapping vwheel brings the package 4to the ydischarge station. Here acam operated ejector plunger 51 (Fig. l) acts to force `the package out vof lthe wrapping wheel and on to a-discharge platform 52. The ejector plunger '51 is mounted on an arm 53 fixed to 4an arm l54. The arm 54 is coupled by a link 55 to a bell crank 56 carrying a follower 57 coacting with a cam 58 on a cam shaft 59. The arm 54 carries a roller 60, which coacts with a tail 61 on an arm 62 carrying the top presser 49 to rock the arm 62 about a pivot 63, and so imparts vthe necessary movements, vunder control of the cam :58, to the heat sealing top presser.

What I yclaim aas my yinvention and desire to secure by Letters Patent is:

l. In a vwrapping :machine for wrapping loose biscuits and the like, .the combinationofza wrapping wheel mounted for intermittent rotation about an Aaxis and arranged to transport in succession toa folding `station stacks of biscuits, each with a wrapper folded around itin 'YU-.formation, a rotary folder at the folding ystation mounted for rotation about .an `axis parallel to that yof the wrapping wheel from afreceiyling to aidischarge position, said rotary folder comprising fa pair of relatively movable jaws defining between rthem Aa 'cleft of .substantial width when said rotary 4folder 'is :in .the receiving position, :an oscillating tucker .blade lwhich operates, on :arrival .of each stack of biscuits at the folding station, lto press the projecting portions Vof the wrapper into said open cleft and thereby to form the first portion of a double fold in the wrapper, means for rotating said rotary folder, .after lwithdrawal of lsaid `tucker eblade from said cleft, linto .its vdischarge position, `said rotary .folder forming the lsecond portion of Ithe double 4fold by such rotation and .permitting in `lits discharge ,position the -double .fold to withdraw from said cle'ft -on continued yrotation of said Wrapping wheel, fand jaw operating `means `operative vduring rotation :o'f said rotary folder from the receiving to the discharge `position first to approach said 'jaws iso zas positively .to crease said double fold and thereafter to open said jaws again.

.2. A Icombination Ias yclaimed in yclaim l., wherein .one of the jaws of .said :rota-ry folder is .fixed and the :other jaw is pivoted lto said Vlixed jaw and wherein said jaw operating means acomprtise's fa lstationary cam Aand a follower attached lto 'said pivoted jaw and cooperatingwith said stationary cam.

3. A combination as claimed in claim .1., wherein f'said rotary folder comprises va vheating element .for preheating said -double :fold duri-ng 'formation thereof :at `the folding station land comprising `a lheat 'sealing member for :applying pressure :to said double fold y'after withdrawal thereof from ythe cleft Vthe rotary folder.

.References Cited nthe i-le of this patent UNITED STATES PATENTS 2,077,431 Neumair Apr. 120, .-1937 2,414,282 Wollett lan. y'14, 1947 2,578,948 Sandberg Dec. L8, 19.51 2,612,740 Russell Oct. .7., 419.52

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