Mechanism For Assembling Sliders For Interlocking Fastener Strips

Abstract

A mechanism for positioning sliders on releasably interlocking rib and groove flexible plastic fasteners which operates to clamp the fastener closed at a closing end of the slider and hold the fastener with the profiles open at the opening end of the slider and press the slider from an engagement position onto the fastener to an operative position with the legs of the slider straddling the rib and groove closure. The mechanism includes a pusher with alternating movement from a slider engaging position to a slider installing position wherein the pusher places the slider on the fastener strips and includes delivery means for bringing individual sliders to said slider engaging position and drive means operating the pusher and the delivery means in phase.

Parent Case Text

This application is a continuation-in-part of my copending application, Ser. No. 770,023 filed Oct. 23, 1968.

Description

The invention relates to means for the intermittent application and positioning of sliders on closures comprising complementary profiled elements capable of being mutually interlocked, but also of being separated under the action of a slider; and it relates more particularly, because it is for this application that it seems to offer most advantage, but not exclusively, to a device for the intermittent application and positioning of flexible sliders on complementary profiled elements provided in the vicinity of the opposite edges of a folded sheet advancing in intermittent manner in the direction of said complementary profiled elements and in front of this device, the latter being arranged so as to engage the sliders on these profiled elements transversely to their direction of movement, this sheet serving especially for obtaining containers such as bags or pouches. The profiled closure elements may form part of strips, preferably of plastic material, which are welded at the edges of the said sheet or they may be in a single part with the sheet, which is then preferably obtained with the elements by extrusion of a plastics material, for example in a form of tube which is split before the positioning of the sliders.

An object of the invention is to provide an improved mechanism which operates to repeatedly install sliders on flexible fastener strips in an improved manner and which is capable of continued high production operation.

As regards the device according to the invention, for the intermittent application of the sliders on a given place of engagement of these sliders on closures of the type concerned, it includes a pusher adapted to undergo movements on a predetermined path, of advance and of retreat relative to the said place and a transverse channel with respect to this path enabling the introduction on itself of successive sliders by means of a system for feeding sliders, the pusher being then adapted to push the slider that it encounters on its path in the said place, when it is advanced towards the latter, this device being characterized by the fact that the feed system includes mechanical means ensuring the advance of the sliders towards said place, the operation of these mechanical means being phase-locked to the alternate movements of the pusher so as to place a fresh slider on the path of the pusher on each advance of the latter towards the aforesaid place.

According to another characteristic of the invention which is used preferably at same time, but if necessary it could be used separately, the sliders, especially when they are flexible, are grouped in a chain in which they are connected by detachable connecting elements.

In a preferred embodiment of the said device, the supply system includes means adapted to make such a chain of sliders advance in the above-said channel by a length equal to the sum of the longitudinal dimensions of a slider and of a connecting element, each time the pusher effects one of its alternate displacements, more particularly each time that it undergoes a movement of withdrawal.

In the case where the device to enable the direct positioning of sliders on the profiled complementary closing elements comprises, in addition to the above-said engagement pusher of the flexible sliders on the closure, on both sides of the pusher and in the direction of intermittent displacement of the said closure elements, a first clamp coacting with a spacer to separate the said profiled elements and a second clamp adapted, on the other hand, to produce interlocking at its level of these complementary elements, these clamps serving to immobilize the closure elements and their support during the positioning of the slider according to another arrangement of the invention. The pusher is rigidly fixed to a carriage comprising pairs of wheels whose rolling tracks are formed on surfaces of opposite branches of the said clamps respectively, these surfaces having cam profiles so that the advance or retreat of the carriage with respect to the above-said closures causes respectively the closure or opening of the above-said grippers, by pivoting of their branches around their respective pivot points, against the action of the elastic return means.

The invention will, in any case, be well understood with the aid of the supplementary description which follows, as well as the accompanying drawings, which supplement and drawings relate to a preferred embodiment of the invention.

FIG. 1 of these drawings, shows, in a view from above, a slider positioning apparatus according to the invention.

FIG. 2 and 3 show, in partial section along 11--11, the apparatus of FIG. 1, respectively after engagement of a slider and prior to the engagement of a slider, the immobilizing clamps not being shown.

FIG. 4 shows a front view of the apparatus according to FIG. 1.

FIG. 5 shows, in partial section along FIG. V--V, the apparatus of FIG. 1.

FIG. 6 shows, in partial section along VI--VI, the apparatus of FIG. 1.

FIGS. 7 and 8 show respectively in plan and in elevation a chain of sliders constituted by several sections of which each comprises a plurality of sliders.

It is proposed to construct a device for the intermittent introduction and positioning of sliders 1, on a folded sheet2 (preferably of plastics material) and advancing in intermittent manner with respect to the above-said device in the direction of the arrow F (FIG. 1 and 4). The said sheet forms along and between its edges 3, a longitudinal slit 4 (FIGS. 3, 4) capable of being enclosed by the interlocking of complementary elements 6, 6a. This sheet 2 is guided and driven (in the direction of the arrow F) by rollers 7, 7a (FIG. 4) for example towards a cutting and welding apparatus (not shown), adapted to cut off the sheet into sections and to weld on to one another the two opposite faces of the sheet along the line of cut, so that each section forms a bag of plastics material.

The device for the application and positioning of sliders according to the invention thus comprises a pusher 8, actuated for example by a jack 10, adapted to undergo advancing and retreating movements, with respect to the emplacement 5 for the positioning of sliders 1 on the complementary profiled elements 6, 6a of the folded sheet 2, these movements having a direction perpendicular to that of the advance of the sheet. A channel 9, transverse with respect to the movement of the slider, enables the introduction on the latter of successive sliders 1 by means of a slide supply system 11, the pusher 8 being then adapted to push the slider that it encounters on its path in the said emplacement 5, when it is advanced towards the latter, the operation of the supply system being phase-locked to the alternate deplacements of the pusher 8 so as to place a fresh slider 1 on the path of the pusher, each time that the latter advances towards the aforesaid emplacement 5.

Although recourse may be had to any other means for the supply in order to ensure the advance of sliders through the supply system recourse is advantageously had to the arrangement of the invention usable besides in other devices for positioning sliders and according to which the sliders 1 form a chain 12 in which the sliders 1 are connected by detachable connecting elements 13, the supply system being arranged so as to cause this chain to advance in the above-said channel 9 by a length equal to the sum of the longitudinal dimensions of a slider 1 and of a connecting element 13, each time that the pusher 8 effects one of its alternate displacements, especially of retreat. The positioning device comprises, in addition, advantageously holding members for the connecting elements 13 adjacent to that of the sliders which is pushed back by the pusher 8, so as to facilitate its detachment from the chain. So that there are connecting elements 13 on both parts of each slider, the chain comprises such elements at each of its ends.

The chain of sliders, which must, especially in the case of positioning by displacement transverse to the advance of the sheet have a certain elasticity, is advantageously made of plastics material, especially by moulding.

To constitute chains of great length, preferably rollable to form a spool, it may be advantageous to produce such chains by several section of which each comprises a plurality of sliders, for example twenty sliders and which are connected between themselves by any suitable mechanism.

The use of moulds of a large size is thus avoided, the length of the moulds corresponding to a section.

In FIGS. 7 and 8 are shown two sections of chain 12a and 12b of sliders 1. At the ends of the sections are provided linking elements 13a and 13b comprising respectively the pins 13c and the holes 13d, which, by their mutual interlocking, enable consecutive sections to be united together to form the complete chain.

The sliders 1 contained in this chain, which are intended to slide straddled on the closure constituted by the complementary elements 5, 5a, include advantageously (FIG. 3), as already known, a small plate 14 bearing, on one hand, two lateral walls 16, 16a bounding, in the inside of the slider, a channel with convergent walls ensuring the interlocking of the closure elements, and on the other hand, a median partition 17 acting as the separating wedge and extending over a portion of the length of the slider, these lateral walls and/or this median partition being provided with end shoulders 18 ensuring the holding of the sliders on the closure after their positioning. As shown in FIGS. 2 and 8, the linking elements 13 have advantageously, in the immediate neighborhood of the adjacent sliders, bevelled forms enabling easy separation of these sliders from these linking elements.

The supply system includes advantageously, to cause step-by-step advance of the chain of sliders, each time by the desired length, a wheel 19 having, at its periphery, slots 21 in which may be partially housed the sliders 1, the said wheel 19 being driven by the pusher 8, especially when the latter retreats, by means of a lever 22 pivoting around the axis of the wheel 19 and having two arms 23 and 24 extending radially; the arm 23 bearing a catch 26 adapted to engage successively in each of the slots 21 and the arm 24 being hinged to a driving rod 27 long which can slide, between two stops 28 and 29, a part 31 rigidly fixed to the pusher 8 or to an element 46 fixed to this pusher.

The supply system can again comprise a catch 32 hinged around a fixed axle adapted to be engaged successively in each of the slots 21 to prevent the wheel 19 from effecting a rotation opposite to that which results from the action of the lever 22 and the catch 26.

The elements 13 have a height less than that of the sliders, which enables these latter to be engaged in the slots 21.

As shown in FIGS. 2 and 3, the wheel 19 is driven in anticlockwise direction when the pusher 8 retreats. The wheel 19 is advantageously arranged tangentially to the channel 9, the latter being then downstream of the wheel 19.

The chain of sliders is guided, upstream of the wheel 19, by a support 25. The engagement of the sliders with the slots 21 of the wheel 19 is ensured by a guiding wall 30 which extends between the support 25 and the channel 9 and which is concentric with the wheel 19.

In a variation, recourse is had, in a place of a singlewheel 19, to two coaxial wheels rigidly fixed in rotation of which one is in engagement with the chain of sliders, while the other constitutes simply a pawl-driven toothed wheel. Moreover, the catch 32 can be replaced by a friction brake.

The above-said retaining members of the connecting elements 13 adjacent to that of the slider which is separated from the chain 12 and urged by the pusher 8 towards the emplacement 5, to be engaged on the complementary elements 6, 6a of the folded sheet, comprise, in one of their preferred embodiments, support surfaces 37, 37a when the pusher urges the corresponding slider toward the emplacement 5.

As shown in FIG. 2, the stops 38, 38a are constituted by pins mounted in sliding manner in housings 40, 40a provided in the pusher 8, the compression springs 39, 39a and the bottoms 41, 41a FIG. 2 of the housing, 40, 40a.

The assembly of sliders in form of a chain which has just been described lends itself particularly well to the positioning of elastic sliders which are positioned by transverse engagement of the latter on strips or sheets provided with complementary profiled elements 5, 5a under the aforesaid conditions and subject to intermittent movements in the direction of these profiled elements, it being understood however that the same assembly could also be used with advantage for the mounting of sliders on these profiled elements in any other manner, especially by longitudinal engagement.

Regarding more particularly the construction of a positioning device by transverse engagement of the slider on complementary profiled elements of the type concerned, this device could be made to include, in a manner known in itself, a first clamp 42 upstream of the pusher, coacting with a spacer 43 separating permanently the supports of the said profiled elements and including grooves 63a, 63to receive these profiled elements and a second clamp 44 downstream of the pusher, the gripping of the clamp 42 (to apply the supports of the complementary profiled elements on the spacer) and of the clamp 44 (to interlock the complementary profiled elements at its level) being actuated simultaneously with the advance of the pusher 8 which is then able to produce the engagement of a slider on the profiled elements, when the latter immobilized.

To ensure these simultaneous actions, recourse is advantageously had to a carriage of which the above-mentioned element 46 forms part, rigidly fixed to the support of the pusher 8 and of the stops 38, 38a and including pairs of wheels 47, 48 of which the rolling paths are formed (FIGS. 5 and 6) on surfaces of opposite arms 42a, 42b and 44a, 44b respectively of the said clamps 42, 44 these surfaces being cam-shaped so that the advance or retreat of the carriage 47, 47a, 48 with respect to the above-said profiled elements cause respectively the closing or opening of the above-said clamps, by pivoting of their arms 42a, 42b and 44a, 44b around their respective hinge points 42c, 44c, this action taking place against the action of elastic return members 49 or 51 for the opening and under the action of return members for the closing.

In the embodiment shown, the pairs of wheels 47, 47' and 48, 48' of the carriage cooperate with the opposite external surfaces 52a, 52b and 53a, 53b of the arms of each of the clamps, the elastic return members 49 and 51 respectively being arranged between the arms of the said clamps (FIG. 5, 6).

This arrangement appears more particularly in FIGS. 4 and 5 which show the shapes of the surfaces 52, 52a and 53, 53a, which shapes include, in the neighborhood of those of the ends of the clamps 42 and 44 which are separated from the folded sheet 2, respectively bosses 55a, 55b, and 56a, 56b.

The clamps are opened and thus enable the advance of the folded sheet 2 when the rollers 47 and 48 are in contact respectively with the bosses 55a, 55b and 56a, 56b.

The height of the bosses 56a, 56b is sufficiently great to enable the passage of the folded sheet with a slider positioned on it when the clamp 44 is open.

The movements of the jack 10 which actuates the pusher 8 and the carriage 46, 47, 48 are synchronized so that with the intermittent advance of the folded sheet 2, this sheet becomes arrested in the period during which the pusher places a slider on the complementary closure elements of the sheet after having, in its travel toward the edges of the folded sheet 2, separated this slider from the linking elements 12. Once the positioning of a slider has been accomplished, the sheet 2 is advanced by an amount which corresponds to the width of a bag or pouch. From the start of this movement, the two clamps 42 and 44 are open. At the end of this movement, the clamps close again and another slider is positioned on the folded sheet.

By means of the invention, the positioning of the sliders on the closing elements is effected, not only entirely automatically, but also with great precision.

As is self-evident, and as emerges besides from this preceding description, the invention is in no way limited to those of its methods of application, nor to those of its methods of production of its various parts, which have been more particularly considered, it embraces, on the contrary, all variations.

Claims

I Claim:

1. A device for positioning sliders on complementary profiled closure elements which comprises, a pusher with alternating movements from a slider engaging position to a slider installing position wherein the pusher places a slider on a closure element with the closure elements being stationary, delivery means for bringing individual sliders to said slider engaging position, and drive means operating the pusher and the delivery means in phase.

2. A device according to claim 1, including means for advancing the closure elements with the alternating movement of the pusher being perpendicular to the direction of the advance of the closure elements, the sliders to be positioned having an elasticity to be able to broaden slightly on their positioning movement and to be attached at the end of the movement of the pusher behind projections formed by the closure elements.

3. A device according to claim 1 characterized by the delivery means operating on a plurality of sliders which are united by detachable connecting elements to form a chain in which the sliders and the connecting elements alternate.

4. A device according to claim 3 characterized by the drive means including an indexing wheel which is in engagement with the said chain and which is driven in intermittent manner as a function of the movements of the pusher.

5. A device according to claim 3, characterized by the fact that the ends of the connecting elements between two consecutive sliders are bevelled in order to facilitate the separation of each slider from the connecting elements which are on both sides of the slider.

6. A device according to claim 3, characterized by the fact that on both sides of the pusher are provided elastic stops which engage the the connecting elements on both sides of a slider urging them against fixed support surfaces between which the said slider passes, so that the pusher separates the slider from the chain of sliders.

7. A device according to claim 6, characterized by the fact that the elastic stops include displaceable pins in a housing supporting the pusher, compression springs are provided between the pins and the bottom of the housing, and a stop at the end opposite to the bottom of each housing ensures the retraction of the pins when the pusher moves to said slider engaging position.

8. A device according to claim 1 including strip clamps operated in synchronism with the movements of the pusher.

9. A device according to claim 8, including cam means operated by said drive means for operating the clamps.

10. A device according to claim 1 including means for locking the closure element in position.

11. A device according to claim 3 including a linking element at the two ends of the chain.

12. A device according to claim 3 wherein said connecting elements are of uniform length.

13. A device according to claim 12, characterized by the fact that the linking elements are constituted by pins and holes which occur at the ends of the chains to be united.

14. A mechanism for positioning sliders on complementary profile closure elements constructed in accordance with claim 1 and including means for holding the closure elements separated at an opening end of the slider and for holding the closure elements together at a closing end of the slider at said slider installing position.