US 3425185 A
Abstract available in
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Description (OCR text may contain errors)
Feb. 4, 1969 B. smwm arm. 3,425,185
PRODUCTION OF SEALED FILLED ENVELOPES Filed Dec. 9, 1966 heet I, or 2 INVENTORS:
BRUCE SAMWAYS DONALD ARTHUR SHORE Kw Mmmaxu Feb. 4, 1969 a. SAMWAYS ETAL 3,425,185
PRODUCTION OF SEALED FILLED ENVELOPES Filed Dec. 9. 1966 sheet l0 1 I l 1 INVENTOBSi:
BRUCE sAMwAYsi DONALD ARTHUR SHORE -U.S. Cl. 53-182 United States Patent ()fifice 3,425,185 PRODUCTION OF SEALED FILLED ENVELOPES Bruce Samways, Bristol, and Donald Arthur Shore, Congresbury, Somerset, England, assignors to Colodense Limited, Bristol, England, a company of Great Britain I and NorthernIreland Filed Dec. 9, 1966, Ser. No. 600,438 7 Claims priority, application Great Britain, Dec. 11, 1965,
52,727/ 65 7 Claims Int. Cl. B65b'9/12, 51/30; B31b 1/38 This invention relates to the production of sealed filled envelopes and, in particular, to an apparatus for packaging articles or measured quantities of goods in sealed envelopes having finger. rupturable seals around the edges of the flaps.
' Apparatus for the continuous packaging of articles or quantities of goods in sealed pouches formed from a travelling sheet of heat-sealable flexible wrapping material is well-known. (See, for example, British patent specification No. 526,148.) A commonly used apparatus comprises a forming member which folds the travelling sheet of wrapping material around a filler tube to form a tube of wrapping material with overlapping edges, a reciprocable sealing member, which may be a heat-seal member, aligned parallel with the filler tube and capable of reciprocating to and from the filler tube for the purpose of sealing successive portions of overlapping edges of the tube of wrapping material, a pair of heat-sealing jaws placed below the filler tube for transversely sealing the tube of wrapping material at pouch length intervals, means for advancing the tube of wrapping material a pouch length at a time and cutting means for severing individual pouches from the continuous string of pouches. A horizontal support for a supply roll of the wrapping material is mounted adjacent to the forming member in sucha position that the sheet ,ofwrapping material can pass centrally over the shoulder or collar of the forming member. Goods are conveniently introduced into the tube of wrapping material through the filler tube between transverse sealing operations so that the goods are sealed in individual pouches.
In British patent specification No. 956,506 there isydescribed a method for forming, filling, and sealing envelopes having finger rupturable seals comprising the steps of drawing a sheet of continous flexible wrapping material having at least one side heat-scalable from asupply, folding one edge of the sheet with a heat-scalable surface inwardsj. part way over the body of the sheet to form a pouch-forming member, folding the other edge of the sheet over the pouch-forming member to forma flapforming member, sealing the flap-forming member to the pouch-forming member alonga longitudinal strip parallel with but remote from the edge of the flap-forming member, heat-sealing the folded material along a transverse strip to seal the flap-forming member, pouch-forming member and body of the sheet together,fillingthe folded material above the transverse seal with a measured quantity ofmerchandise, forwarding the sheet material by an amount equal to the desired length of one envelope, heatsealing the folded material above the merchandise along a transverse strip, severing the filled envelope by cutting Patented Feb. 4, 1969 through the transverse seal and then repeating the filling, sealing and severing operation, the seals between the flap-forming member and the pouch-forming member being weaker than the seals between the pouch-forming member and the body of the sheet. The flap-forming member may be sealed to the pouch-forming member along the longitudinal strip by means of a heat-seal or by means of an adhesive seal, for example a polyvinyl acetate solution or emulsion.
When attempts have been made to form, fill and seal envelopes in accordance with the method described in British patent specification No. 956,506 using the prior art apparatus for sealing articles in pouches, it has been found that certain difficulties may arise.
In the manufacture of the pouches of the prior art, the overlap of the edges of the tube is small and the position of the diametrical line about which the tube is collapsed at the transverse heat seals with respect to the position of the overlap, is not critically important and may be permitted to vary over a fairly wide range Without the quality of the pouch being affected. However, when the manufacture of envelopes in accordance with British specification No. 956,506 is attempted, it is necessary to provide a comparatively large overlap of the tube edges to define the pouch-forming member and the flap-forming member and the position of the diametrical line of collapse of the tube is very important. For example, if the tube is collapsed so that the hinge line of the flap-forming member is much above the open edge of the pouchforming member, the depth of the pouch-forming member and thus the capacity of the pouch in each of the finished envelopes is reduced. Further, since the fiap in each envelope is sealed to the body of the envelope above the pouch by a strong seal, tearing of the envelope can occur on opening the flap. Furthermore after the envelopes have been opened and then reclosed, goods can leak through gaps between the hinge line and the edge of the pouch in the envelopes.
On the other hand, if the tube is collapsed so that the hinge line of the flap-forming member is below the open edge of the pouch-forming member, on forming the trans verse heat-seals, the top edge of the pouch-forming member will be folded over forming four thicknesses of material, which is undesirable.
It is, thus, desirable in the manufacture of the envelopes to be able to adjust the position of the diametrical line about which the tube is collapsed with the minimum of difficulty and so align the hinge line of the flap-forming member in a desired position with respect to the edge of the pouch-forming member, preferably, while the apparatus is in motion. To achieve this, it is inconvenient to move the cumbersome transverse sealing mechanism with its associated driving means.
The present invention is concerned with an apparatus for the continous production of sealed filled envelopes in which the position of the diametrical line about which the transverse seals are made across the tube of wrapping material may readily be shifted.
Accordingly, the present invention includes an apparatus for the continuous production of sealed filled envelopes comprising a downwardly directed filler tube through which goods may be fed, a forming member mounted for rotation about the filler tube for forming a travelling sheet of heat-scalable wrapping material into a tube having overlapping edges about the filler tube, a support for a supply of wrapping material fixed to the forming member and mounted for angular movement with the forming member about the longitudinal axis of the filler tube, a sealing means for sealing the overlapping edges of the tube of wrapping material along a longitudinal strip, advancing means for progressing said tube downwards from the filler tube, a pair of reciprocable heat-seal jaws placed beneath the filler tube for transversely sealing together opposed walls of the tube of wrapping material at envelope length intervals and a cutting means for separating individual sealed filled envelopes from the tube.
By swinging the support and forming member about the filler tube, the travelling tube of wrapping material passing over the filler tube is caused to rotate about the filler tube with respect to the reciprocable heat-seal jaws so that the position of the diametrical line about which the transverse seals are made across the tube of wrapping material may readily be adjusted.
The reciprocable heat-seal jaws preferably incorporate the progressing means by being arranged to be given a downward motion when pressed together upon the tube of wrapping material, so advancing the tube while effecting a transverse heat seal, and to be given an upward motion when the jaws are open and substantially out of Contact with the tube of wrapping material.
In one form of the invention, the sealing means includes an adhesive applicator for applying a strip of a liquid adhesive along the travelling sheet of Wrapping material before it is formed into a tube about the forming member so that the strip lies between the two overlapping edges of thetube of wrapping material at the position it is desired to secure the two edges together. The position of the applicator may be adjusted as may be required transversely across the width of the sheet to ensure that the seal will be in the optimum position for the flap-forming member. The tension in the wrap-over of the tube may be suflicient to ensure adhesion of the overlapped edges along the strip of liquid adhesive. Preferably, however, a reciprocable sealing bar parallel with the filler tube and capable of being reciprocated towards and away from the filler tube is provided for pressing the overlapping edges against the filler tube to ensure a satisfactory seal along the adhesive strip. The reciprocable sealing bar can also serve to hold the tube of wrapping material against the filler tube during the sealing operation and prevent undesirable longitudinal movement of the tube of wrapping material during rest periods between positive advancement of the tube. If such a reciprocable sealing bar is not employed it may be desirable to have some other reciprocal braking means to hold the tube of wrapping material stationary when longitudinal movement is not desired.
In another form of the apparatus, the sealing means is a reciprocable heat-sealing bar parallel with the filler tube and capable of being reciprocated towards and away from the filler tube for heat-sealing the overlapping edges of the tube of wrapping material along the desired longitudinal strip.
In still another form of the apparatus, an adhesive .applicator is included for applying the strip of liquid adhesive along the travelling sheet in the desired position and a reciprocable heat sealing bar is provided to form a heat-seal line along a longitudinal strip alongside the adhesive strip and nearer to the exposed edge of the overlapping edges of the tube of wrapping material. A separate reciprocable sealing bar may be provided for pressing the overlapped edges along the line of the adhesive seal strip but in normal circumstances the pressure of the reciprocable heat-sealing bar when forming the heat-seal strip is sufiicient to ensure adequate adhesion of the overlapped edges of the tube of wrapping material along the adhesive strip. By use of this form of apparatus a sealed filled envelope is formed with a flap having two seals, first a heat-seal which is ruptured when the envelope flap is peeled open for the first time and second, an adhesive seal which conveniently may be formed from a tacky adhesive which permits reclosing of the flap of the envelope if the contents are not consumed on a first, second or further opening.
The adhesive applied by the adhesive applicator may be of any of the known tacky adhesives applied as a solution, emulsion or hot melt.
The heat-scalable wrapping material may be any of the conventional flexible wrapping materials having at least one surface heat-scalable and delivered to the apparatus in such a direction that a heat-scalable surface lies inisde the formed tube. Also, to ensure that heat-seals between the flap-forming member and the pouch-forming member are .weaker than the seals between the pouch-forming member, the wrapping material may be overprinted in the area which is to provide the flap-forming members, particularly at the places where the heat-seals are to take place.
The invention will now be further described and ascertained by way of a specific example with reference to the accompanying drawings in which:
FIGURE 1 is a diagrammatic front elevation of apparatus according to the invention,
FIGURE 2 is a side elevation of a part of FIGURE 1,
FIGURE 3 is a section in the plane A- A of FIGURE FIGURE 4 is a section in the plane BB of FIGURE FIGURE 5 is a diagram showing in section the collapse of a tube of wrapping material along a diametrical line shown in FIGURE 4, and
FIGURES 6 and 7 are front elevations of alternative forms of sealed and filled envelopes.
Referring to FIGURE 1, a filler tube 1 fixed to a frame member 2 is fitted with a forming member 3 which is freely rotatable about the tube 1 and which has the form of a scroll with a high pointed, smoothly rounded collar 4. The forming member 3 is fixed to a carrier 5 which is pivoted for movement about the axis of the filler tube 1 at a rotary mounting 6. The carrier 5 has a horizontal support 7 for a roll 17 of sheet wrapping material, an adhesive applicator roll -8 dipping into an adhesive container 9 and associated guiding rollers 10, 1-1 for the sheet. The angular position of the carrier 5 may be locked by a screw 12.
Below the forming member 3 but in line with the filler tube 1 is placed a plane sealer bar 13 which is capable of reciprocating towards and away from the filler tube 1 by a reciprocating drive mechanism (not shown). Directly below the filler tube 1 a pair of reciprocable heat-seal jaws 14 are placed either side of the projected longitudinal axis of the filler tube 1 and they are mounted upon means 34 for reciprocating them towards and away from each other. Said means 34 are also capable of reciprocating the jaws, so that while closed they can be brought to the lower position shown in dotted outline. The jaws 14 incorporate cutters 15 capable of cutting sheet material gripped between themf The apparatus operates as follows in the production of sealed filled envelopes of the type described in specification No. 956,506:
A sheet 16 of flexible wrapping material heat-sealable at least on one surface (for example, one-side polytheme-coated cellulose film) is drawn from the supply roll 17 mounted on the horizontal support 7 and passes round the guiding rollers 10, 11 where it receives a longitudinal strip 18 of tacky adhesive applied by the applicator roll 8 at a predetermined distance from one edge of the sheet 16. The sheet 16 then passes over the collar 4 of the forming member 3 where it is caused to form a tube 16' around the filler tube 1, with overlapping edge portions 19, 20 and with a heat seal-able surface innermost. The innermost, overlapped edge portion 19 is a pouchforming member and is destined to form one wall of the pouch of each complete envelope and the outermost overlapping edge portion 20 is a flap-forming member and is destined to form the flap. When the tube 16' has been drawn below the former member 3 (FIGURE 4) and is still supported by the filler tube 1, the overlapping edge portions 19, 20 of the tube 16 lie opposite the reciprocable sealer bar 13 which moves forward and presses the edge portions 19, 20 along the line of the adhesive strip 18 against the filler'tube 1 to secure the edge portions '19, 20 together.
The tube 16' is then drawn oif the end of the tiller tube 1 and is transversely heat-sealed between the jaws 14. It is desirable that the jaws 14 so collapse the tube that the transverse heat-seal takes place about a diametrical line (as shown at 21 in FIGURE 4) so positioned that a hinge line 22 is formed (as shown in FIGURE that substantially coincides with the edge 23 of the edge portion 19 on completion of the seal. The rotational position of the diametrica'l line 21 of collapse of the tube 16' on transverse heat-sealing may be adjusted as required, thus altering the position of the hinge line 22 relative to the tube overlap, by swinging the carrier 5 with the former member 3 about the mounting 6 so that the tube 1'6 is rotated upon the filler tube 1 relative to the heat-seal jaws '14. When the desired position for the tube 16 has been fiound, the carrier 5 may be locked into position by the screw 12.
To ensure that a transverse seal 24 between the overlapping edge portions 19, 20 is weaker than the seal between the inner surfaces of the tube 16, the sheet 16 has printed areas 25 extending inward-1y from the flapforming edge for a predetermined distance and separated by a distance equal to the predetermined length of an envelope. The transverse heat-seal 24 is applied in line with a printed area 25.
During each transverse sealing cycle, an envelope 27 is sealed with a determined quantity of goods 26 enclosed and is cut from the advancing tube 16'. While the jaws 14 still grip the tube 16', they are moved down by a distance of one envelope length, thus drawing the sheet 16 from the roll 17 and the tube 16' over the filler tube 1. During this period, goods 26 (tor example, sweets) are introduced into the tube 16' above the transverse heatseat by way of filler tube '1. Finally, the knives 15 cut through the centre of the transverse seal 24 cutting oil from the tube 16 a sealed filled envelope 27 (FIGURE 6) and the jaws 1*4 retract and return to the upward position preparatory for a new cycle of events. The operation of the reciprocable sealer bar 13 is synchronised with the operation of the heat-seal jaws 14 so that when the jaws are open and moving upwards, the sealer bar 13 is pressed against the edge portions 19, 20. Thus, as well as ensuring that the edge-portions 19, 20 are securely sealed along the adhesive slip 18, the sealer bar 13 also holds the tube 16' firmly against the filler tube 1 so that there is no undesirable longitudinal movement of the tube 16 when the tube 16' is not gripped by the jaws 14.
By use of the apparatus described it will be appreciated that envelopes 27 of dilferent sizes and with different sizes of flap and pouch portions may be manufactured. Any variation in the desired position of the transverse seals 24 may be made by swinging the carrier 5 with former member 3 to cause the tube 16' to rotate with respect to the jaws 14. If the variation is appreciable it may be necessary to adjust also the position of the applicator 8 to ensure that the adhesive strip 18 also is in the correct position and in line with the sealer bar 13-.
It will be appreciated that the adhesive applicator roll 8 may be dispensed with and the sealer bar 13' heated to form a longitudinal heat-seal strip between the edge portions 19, 20 in place of the adhesive strip 18. With such an arrangement, it is preferable that an overprinted strip is provided on the sheet to weaken suitably the heat-seal formed by the heated sealer bar 13. 7
If desired, the edge portions 19, 20 maybe sealed by an adhesive seal strip alongside a heat-seal strip, the heatseal strip'being nearer to the edge of the outermost, flaptorming edge portion 20. This is achieved byapplying the adhesive strip as described and forming a heat-seal strip by providing a reciprocable heat-seal bar which strikes the overlapping edge portions 19, 20 alongside the adhesion strip. The pressure exerted by the heat-seal bar is usually suflicient to cause the portions 19, 20 to seal adequately along the adjacent adhesive strip without the necessity to provide a separate reciprocable sealing bar for the adhesive seal.
An envelope 27 having the flap 30 sealed with a heatseal strip 29 and an adhesive seal strip 28 is illustrated in FIGURE 7. The heat-seal strip 29 may be weakened by prior overprinting (not shown) of the wrapping material. On opening the envelope 27 for the first time, it is necessary to rupture both seals 28 and 29 to obtain access to the contents. However, since the adhesive seal 28 is of a tacky nature the envelope 27' may be reclosed by sealing the flap 30 to the pouch 31 along the adhesive seal 28.
What we claim and desire to secure by Letters Patent 1s:
1. An apparatus for the continuous production of sealed filled envelopes comprising a downwardly directed filler tube down which goods may be fed, a forming member mounted for rotation about the filler tube for forming a travelling sheet of heat-scalable wrapping material into a tube having overlapping edges about the tiller tube, a support for a supply of wrapping material tfixed to the forming member and mounted for angular movement with the forming member about the longitudinal axis of the filler tube, a sealing means for sealing the overlapping edges of the tube of wrapping material along a longitudinal strip, advancing means for progressing said tube of wrapping material downwards from the filler tube, a pair of heat-seal jaws placed beneath the filler tube to be reciprocable towards and away from the filler tube axis for transversely sealing together opposed walls of the tube of wrapping material at envelope length intervals and a cutting means placed beneath the filler tube for separating individual sealed filled envelopes from the tube. I
2. An apparatus as claimed in claim 11 in which the reciprocable heat-seal jaws are arranged to be incorporated in the advancing means, said jaws being mounted for downward motion when pressed together upon the tube of wrapping material so as to advance the tube while effecting a transverse heat seal and being capable of upward motion when the jaws are open and substantially out of contact with the tube of wrapping material.
3. An apparatus according to claim 2 having a sealing bar extending parallel with the filler tube axis and mounted for reciprocation towards and away from the filler tube for sealing together the overlapping edges of the tube of wrapping material along a longitudinal strip, said bar being arranged to press said overlapping edges against the filler tube for that period of each cycle of the apparatus during which the pair of heat-sealing jaws are open.
4. An apparatus as claimed in claim 1 in which the sealing means includes an adhesive applicator for applying a strip of adhesive along the travelling sheet.
5. An apparatus as claimed in claim 4 in which a sealing bar extending parallel with the tiller tube axis and mounted for reciprocation towards and away from the filler tube, is provided for pressing the overlapping edges of the tube of wrapping material against the filler tube to ensure a seal along the adhesive strip.
6. -An apparatus as claimed in claim 4 provided with 7 8 a heat-sealing bar extending parallel with the filler tube References Cited axis and mounted for reciprocation towards and away UNITED STATES PATENTS from the filler tube for heat-sealing the overlapping edges of the tube of wrapping material along a strip adjacent 3210'907 10/1965 Thurlings 53 180 the adhesive strip and nearer to the exposed edge of the 5 3'296770 1/1967 Wllson 53-182 3,314,215 4/1967 Alfred 53182 overlapping edges.
7. An apparatus as claimed in claim 1 in which the sealing means is a heat-sealing bar extending parallel with TRAVIS MCGEHEE Primary Examiner the filler tube axis and mounted for reciprocation towards R L, SPRUIL, Assistant Examiner. and away from the filler tube for heat-sealing the overlapping edges of the tube of wrapping material along 10 US. Cl. X.R.
a longitudinal strip. 93-82