(1) FIELD OF THE INVENTION

This invention relates to the securement of flexible sheet material such as in mattress manufacture, and more particularly to pocket spring mattress manufacture together with methods and apparatus for securing mattress springs within fabric pockets to form a spring "armature" for the mattress prior to the application of ticking.

(2) DESCRIPTION OF THE PRIOR ART

Specific reference is made to international patent application PCT/CA94/00055 in the name of Springquilt Industries Limited, New Zealand patent specification no. 235733 in the name of Slumberland Pic and New Zealand patent specification no. 211505 in the name of Simmons USA Corporation. Such specifications disclose methods of manufacture of pocketed spring armature assemblies for mattresses with which the method and apparatus of the present invention can be utilised.

In the past, pocketed spring arrangements, including those referred to above, generally incorporate a textile or fabric encapsulation of each spring for the purpose of separating each spring from direct contact with one another.

Various methods are provided for encapsulating the springs. Most arrangements include the preformation of the textile or fabric encapsulating material into a semi-formed enclosure; for example an elongate sleeve, within which springs are positioned during the manufacturing phase. The springs are subsequently separated one from the other within the sleeve by drawing in and fixing adjacent portions of the sleeve with one another.

Various methods of fixing the textile or fabric material have been utilised including adhesive and/or heat bonding, the use of clips, stitching and the like.

Significant difficulties surround prior art methods of fixing, including the long term security of the securement and establishment of "point loads" where clipping arrangements are utilised rendering the fabric adjacent the securement likely to tear or otherwise become damaged in use.

It has also been found that the step of securing portions of the sleeve with one another between the springs is a the major impediment to a significant increase in manufacturing speed for such mattresses and in automation of manufacturing processes.

OBJECT OF THE INVENTION

It is accordingly an object of this invention to come some way in overcoming the abovementioned problems or at least provide the public with a useful choice. Other objects of this invention become apparent from the following description.

SUMMARY OF THE INVENTION

According to one aspect of this invention there is provided a method of at least partially enclosing springs in separate pockets of flexible sheet material, including the steps of at least partially preforming a spring pocket in said flexible sheet material with said pocket having a closable opening thereto, positioning said spring in said pocket, closing said opening by clamp means which bring opposing portions of said flexible sheet material defining said opening in juxtaposition, said clamp means corrugating said opposing portions, inserting a elongate engaging portion through said corrugations to at least partially close said pocket opening about said spring.

According to a further aspect of this invention there is provided a pocket spring assembly including at least a pair of springs each engaged in a flexible sheet material pocket, separated one from the other, wherein said pocket has an opening provided for insertion of

said spring into a partially pre-formed pocket which is closed by an elongate engaging means having mid-portions engaged through portions of said material forming said opening substantially opposing one another, said engaging means positioned alternately on each side of said flexible sheet material and through said opposing portions.

According to a further aspect of this invention there is provided a means of securing flexible sheet material as a pocket about a spring including at least a pair of cooperating jaws arranged to engage the flexible sheet material adjacent an opening of a partially formed spring pocket therein, said jaws having opposing correspondingly shaped corrugating means adapted to clamp and corrugate portions of said sheet material positioned there between, insertion means provided to pass an engaging means through the portions of said sheet material corrugated by said jaws and position a mid-portion of said engaging means through said corrugations with portions of said engaging means positioned to alternate sides of said sheet material.

According to a further aspect there is provided a method for securing at least two layers of flexible sheet material together comprising the steps of:

Positioning said at least two layers of flexible sheet material between opposed clamp means having co-operating corrugations on adjacent faces;

Bringing said clamp means towards each other to corrugate said flexible sheet material between said adjacent faces of said clamp means; and,

Inserting an elongate engaging portion through said corrugated flexible sheet material such that portions of said elongate engaging member are positioned on alternate sides of said flexible sheet material.

Other aspects of this invention will become apparent from the following description. Modifications are envisaged and may be incorporated without departing from the scope or spirit of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The description is also made with reference to drawings in which:

Figure 1 is a substantially diagrammatic perspective view of jaws for the securement method and means according to the invention.

Figure 2 is a substantially diagrammatic side elevation of the apparatus of Figure 1, showing portions of fabric forming the pocket corrugated therebetween.

Figure 3 is a substantially diagrammatic partial side elevation showing pocketed springs secured according to the method and apparatus of the invention and in a orientation according to Arrow A of Figure 4 referred to hereafter.

Figure 4 is a substantially diagrammatic plan view in the direction of Arrow B of Figure 3 showing a portion of a pocketed spring armature secured according the method and apparatus of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Whilst in this form of the invention reference is made to the provision of pocketed springs for use in forming a mattress armature, together with apparatus and methods relevant thereto, it is to be appreciated that the invention is not limited merely to such activity. The invention can also be applied to alternative spring pocketing arrangements, such as that used in cushioning and the like. Further, the invention relates to methods and apparatus for the securement of flexible sheet

material such as fabric and may be utilised in related fields of endeavour. For example, this invention may be used to fix fabric layers for curtains or other such items.

The preferred form of the invention will be described with reference to spring pocketing arrangements, such as that typically used in the mattress manufacturing industry, where spring pockets are substantially preformed in flexible sheet material, for example spun polyester fabric and the like, as one or a number of elongate sleeves into which mattress springs can be inserted. Subsequently insertion portions of the sleeve between the springs are brought together and held to achieve separation of the springs one from the other in a "pocket".

It will be appreciated that the pocketing of springs is desirable to hold springs substantially in position in the formation of an armature and to enable springs to operate substantially independently one relative to the other and to reduce interference with adjacent springs and the like.

The invention is directed to a method and apparatus for achieving convenient secure and rapid

engagement of these springs one relative to the other in spring pockets.

In the preferred form of the invention, the apparatus is provided toward an output end of a spring pocketing apparatus, such as those referred to herein before and preferably, by way of example only, as an alternative to fastener applying mechanisms 80 as described in international patent specification PCT/ CA94/00055.

In the preferred form of the invention, a commensurate number of corrugating jaws are provided adjacent the output of the spring pocketing apparatus commensurate with the number of "lines" of springs emerging from the pocketing apparatus.

In the preferred form of the invention, preferably the jaws are actuated by pneumatics, electro-pneumatics/ hydraulics and the like, timed to coact with other operational apparatus of the spring pocketing apparatus.

Preferably the corrugating jaws can be bought into and out of active engagement with the output of the spring pocketing apparatus to suit and in cooperation with the operational characteristics of the machinery with which it is mounted.

Preferably the spring pocketing apparatus with which the securement means is utilised feeds a sleeve of sheet fabric material therefrom, into which springs have been inserted. It will be appreciated that as each spring is enclosed within the spring pocket by fastening means, an open ended pocket is engaged within which the next adjacent spring is positioned.

The objective of the fastening apparatus and method of the present invention is to provide a method and apparatus for effectively and rapidly substantially closing the open spring pocket about the spring positioned in the open pocket, so as to separate that spring from adjacent springs.

For the purposes of context and to provide clarity for the description which follows, it will be appreciated that in the final configuration, as shown in Figures 3 and 4, springs S are substantially housed within a fabric pocket P which in the preferred form of the invention has a "sleeve orientation" in the direction of Arrow 0, that is, prior to enclosing of springs S within the pocket P the fabric is at least partially formed into a sleeve having a hollow longitudinal orientation according to the direction of Arrows 0.

Turning now particularly to Figures 1 and 2, the apparatus and method according to this invention incorporates a pair of actuable jaws 1, provided to be bought into and out of actuable position, sequenced according to the output operation of the row of springs S according to the orientation O referred to herein before with reference to Figures 3 and 4.

The jaws 1 in the preferred form of the invention are preferably arranged to in their operative position move from a separated position as substantially shown diagrammatically in Figure 1, to a clamping position as is shown by Figure 2. It will be appreciated that during clamping, two sheets of fabric F forming the sleeve to define the pocket P are compressed together between the jaws 1 and between the springs S, as will be seen with reference to Figure 4.

Preferably outer portions 2 of the jaws 1 remote from an operational carriage (not shown) define a pair of cooperatively arranged corrugating faces 3, provided to enmesh one with the other as is shown by Figure 2, but provide sufficient working tolerance therebetween, to enable corresponding corrugation of the fabric F therebetween.

The corrugating faces 3 are also preferably slotted by longitudinally arranged slots 4 and preferably an upper portion 5 of the jaws 1 are longitudinally slotted at 6, to house a substantially channelled reciprocating needle 7 or insertion means which is arranged on the carriage with reciprocating means (not shown) , so as to reciprocate longitudinally of the jaws 1, through the slot 6 and slot 4, whilst the fabric F is corrugated therebetween.

The needle 7 is preferably arranged with a recess near the distil end thereof to house an enlargement or lug 10 of a elongate deformable engaging means 8, the engaging means 8 having preferably an elongate body portion 9 with enlargements 10 arranged transversely on opposing end portions thereof, at least one of the enlargements 10 is arranged to engage within the recess in the distil end of the needle 7, with the elongate body portion substantially flanking the needle rearwardly of the distil end, such that when the needle 7 is inserted through the corrugated fabric F, the recess engaging enlargement 10 is carried through the fabric f with the elongate body portion 9 engaged through the fabric, with the opposing enlargement 10 remaining in position behind.

In the preferred form of the invention, preferably a substantially independently reciprocable pusher rod 11 is also provided to facilitate dislodgement of the engaging means 8, specifically the lug 10, recess engaged with the needle 7 during reciprocation of the insertion means 7, preferably at maximum outward stroke to achieve release of the engaging means 8 at the commencement of the return stroke and to position the previously recess engaged enlargement or lug 10 to one side of the fabric F, with the elongate body portion passing through the concertinaed layers of fabric F.

With specific reference to Figure 2, it will be appreciated that the jaws 1 are closed over the layers of fabric F in the "between-spring" S region so as to corrugate the two layers of fabric as is shown by Figure 2 between the lower portions 2. Thereafter, the insertion means 7 reciprocates relative to the jaws 1 to the position substantially as is shown by Figure 2, where an outer lower tip 7a of the insertion means 7 projects beyond a lower most corrugation of the fabric F and the adjacent enlargement 10 of the securement means 8 is then dislodged from the insertion means 7, for example at the initiation of a return reciprocation of the insertion means 7 out of phase with the pusher rod 11 which remains for a period in the extended position.

It will be appreciated that on the outward reciprocation of the insertion means 7, the body portion 9 between the enlargements or lugs 10 of the engaging means 8 is carried through alternate surfaces of the two layers of fabric F by puncturing of the fabric F by the tip 7a of the insertion means 7.

Upon withdrawal of the insertion means 7, it will be appreciated that the engaging means 8 remains in position, holding the layers of fabric F together, by the body portion 9 passing on alternate sides of the fabric F through holes in the fabric thus closing an opening to said pocket P within which the spring S is engaged.

It will be appreciated that owing to the relatively long length of inter-engagement of the body portion 9 with the fabric F and the multiplicity of apertures through which the engaging means 8 engages the fabric F, "point loads" are in most instances reduced and the likelihood of tearing of the fabric F upon high loads being encountered is reduced over traditional clipping methods. Further, it will be appreciated that the method and apparatus for engagement also facilitates rapid operation, particularly over adhesive/fusion processes common hitherto.

Whilst the invention has been described with reference to a specific deformable attachment means the invention is not limited to use of that product and it is to be appreciated that any needle insertable elongate attachment means having substantially terminal enlargement means can be utilised according to the method and apparatus of this invention.

Whilst the invention is intended for use with spring pocketing machinery as has been hereinbefore described, it is envisaged that the securement apparatus can be used on a variety of pocketing machines. In one instance, it is envisaged that a plurality of the jaw assemblies of the invention can be provided in a substantially "ganged" arrangement on a framework, which also mounts via carriages, moveable fabric supporting means, over which fabric sleeves into which springs can be pocketed by the jaws of this invention, can be mounted.

In such an arrangement it is envisaged that a pair of fabric support means assemblies can be positioned on independently operable carriages which can move into position for insertion of springs and pocketing using the jaws of the present invention and once pocketed, the carriage can move out of position for recharging with a further subsequent fabric sleeve installation. A

similarly arranged carriage then moves into position for spring pocketing and so on, to thus enable a substantially continuous process of spring pocketing to be achieved.

As shown in Figure 4, two engagements means 10 may be inserted to engage the layers of fabric F between adjacent springs S. In such an arrangement, an apparatus as previously described may be duplicated such that two pairs of clamp means and engagement means are utilised for each of the closures between adjacent springs S. These may be provided to operate one above the other and in either the same general direction such as downwardly substantially parallel with the longitudinal axis of the springs S or, if desired, in opposite directions from upper and lower edges of the spring pockets. The use of two or more such engagement means may be preferred in some instances rather than a longer engagement means used to cover the entire distance requiring closure.

Thus by this invention there is provided a method and apparatus for securement of springs in pockets and/ or of securing flexible sheet material.