GB2227654A - Machine for assembling upholstery springs into an upholstery unit - Google Patents

Abstract

A machine (10) for assembling upholstery springs (23) between two sheets of material (13, 14) to form an upholstery unit, in which the springs are arranged in lines at any required spacing apart from each other along each line, and with the lines of springs being spaced apart along the length of the upholstery unit at any required spacing also, comprises first and second supply means (11 and 12) which supply upper and lower webs (13 and 14) to pass through the machine and, guide means in the form of a pair of upper and lower endless conveyors (15 and 16) which guide the webs (13 and 14) through the machine along respective upper and lower paths from an input station (17) to a discharge station (18). An adhesive applicator head (19) at the input station (17) carries out linear reciprocation in a direction transversely of the path of travel of the webs (13 and 14) to apply adhesive to the facing sides of the webs, and a spring loading device (20) applies a line of individual springs (23) onto the upper side of the lower web (14) after application of adhesive thereto. Cutting means, e.g. a rotary cutter blade 22, at the discharge station 18 cuts the upper and lower webs between two lines of springs to form a required length of upholstery unit. <IMAGE>

Description

MACHINE FOR ASSEMBLING UPHOLSTERY SPRINGS INTO AN UPHOLSTERY UNIT The invention relates to a machine for assembling upholstery springs into an upholstery unit.

For the purposes of this specification, the term "upholstery unit" is intended to include wholly or partly formed spring mattresses or divan units, spring upholstered pads of the type used to form a seating pad, back rest or other sprung pad of the type used in the assembly of chairs, settees and beds and other articles of furniture; and spring units formed of springs assembled between a pair of sheets of material, such as insulator pads, and intended to form a component part of a spring upholstered unit.

In the manufacture of spring mattresses, it has been conventional practice for many years to form a spring assembly which is composed of upper and lower rectangular wire frames, and an arrangement of coil springs which are connected to each other, and also to the upper and lower frames, so as to form a unitary spring assembly. The coil springs are usually interconnected at their upper and lower ends by connecting wires or "pigtail" linkages, which are anchored at their ends to the upper or lower rectangular wire frames.

Semi-automatic (and also automatic) spring making machines are used which "wire-up" an assembly of coil springs so as to form the unitary assembly, and to enable the machines to perform efficiently and without undue complications, it is essential that the coil springs should be of uniform size and / or uniform distribution throughout the assembly.

However, it is a fact that certain areas of a.mattress are normally subjected to a greater load than others, and over a period of time the springs supporting these areas tend to become deformed with resultant formation of permanent depressions in the surface of the mattress.

While it might be desirable to seek to anticipate such additional loading in certain areas of a mattress (in order to increase the service life of the mattress), by using stronger springs, or a more dense array of springs to support these areas, these cannot presently be achieved with existing machines. Thus, the use of stronger (larger) springs, or a variable density of springs, cannot be accepted by existing machines which require a uniform size and distribution of the springs in order to carry out semiautomatic assembly of the springs.

It has been proposed in International publication No W088/00804 to provide a spring mattress or upholstery pad assembly which comprises a number of laterally spaced compression springs which extend between upper and lower layers of flexible textile material, and the spring ends are adhesively secured to the layers of textile material by holt melt adhesive droplets. The droplets are moulded into trough-shaped form in order to retain captive against lateral displacement the coil spring end. Therefore, it is possible for coil springs to be assembled in a mattress without the necessity for the springs to be mechanically interconnected by wire or other mechanical linkages to the usual upper and lower rectangular supporting frames.

The present invention is concerned with a novel construction of machine for assembling upholstery springs into an upholstery unit, using suitable adhesive to retain the spring ends against lateral movement relative to adjacent sheet material of or intended to form a part of an upholstery unit.

The invention therefore enables upholstery springs to be assembled in improved manner into an upholstery unit, and will be of considerable utility, given that the use of the alternative medium for upholstery pads of plastics foam slabs is now unacceptable, from a fire hazard point of view, in view of the lethal toxic fumes which are generated during a fire. This is particularly the case for upholstered pads used in aircraft, or other environments where the prevention of fire hazards is paramount.

According to the invention there is provided a machine for assembling upholstery springs between two sheets of material to form an upholstery unit, the springs being arranged in lines which are spaced apart throughout the length of the upholstery unit, and the machine comprising: first and second supply means for supplying respective upper and lower webs of material to pass through the machine, said webs being intended to form said two sheets of an upholstery unit; guide means for guiding said webs through the machine along respective spaced apart upper and lower paths of travel which extend from an input station at an upstream end to a discharge station at a downstream end;; an adhesive applicator head mounted at the input station to carry out linear reciprocation in a direction transversely of said paths, said head being operable to apply adhesive to the sides of the webs which face each other as they travel to the discharge station and along lines corresponding with the intended placement of a line of springs between the two webs; a spring loading device mounted at the input station and operable to hold a line of individual springs and to apply the springs onto the upper side of the lower web after application of adhesive thereto along said placement line; means for applying the upper web onto the upper ends of the springs, after application of adhesive to the upper web;; means for advancing the webs with the line of springs therebetween by one increment of spring line separation towards said discharge station so that a further line of springs can be assembled; and, cutting means at the discharge station operable to cut the upper and lower webs between two lines of springs so as to form a required length of upholstery unit composed of a plurality of springs arranged in lines between two sheets of material and spaced apart from each other along the length of the upholstery unit.

Therefore, in use of a machine according to the invention, an upholstery unit can be obtained having any required spring density throughout specific areas of the upholstery unit e.g. a more dense array of springs may be required at certain regions of the upholstery unit than at others, though of course equal or variable spacing of individual springs along each placement line may be achieved, and similarly the spacing apart of the placement lines may be equal, or varied to suit requirements. All of these options are possible in a machine according to the invention, since individual springs can be assembled into lines without there being any interconnection between adjacent springs, and the location in position of each spring is achieved solely by lateral restraint provided at each spring end where it engages respective parts of the adhesive applied to the webs.

The adhesive applicator head may apply the adhesive in any required manner along the placement lines, and this may comprise continuous lines of adhesive, part continuous, part intermittent supply, or any other arrangement, such as intermittent jetting of blobs of adhesive at spacings apart along the placement line to suit the spacing apart of the springs -which will be held on the spring loading device.

In one preferred arrangement, the adhesive applicator head may apply discrete portions or blobs of adhesive along two lines on each web, so that the usual circular end of a spring can be pressed into the adhesive before it has set and will be laterally located by moulding itself into the adhesive before the latter has set.

To provide a still more secure location of the springs near the edges of the upholstery unit, continuous lines of adhesive may be applied to the webs along the initial traverse of the adhesive applicator head from the edges, so that the spring ends which are embedded in these lines will be more securely located, by virtue of the impregnation, at least partially, of the lines of adhesive into larger areas of the web material.

The spring loading device may take the form of a magazine having holders for each spring, and which may be loaded manually or by an automatic supply arrangement.

The springs may conveniently be coil springs of the type normally used in mattresses when supplied in already wired-up assemblies, though of course the springs will be supplied to their holders as separate components in a machine according to the invention. The holders may take the form of pockets which are arranged so that the springs can be loaded and held horizontally prior to placement onto the lower web, and they may be held releasably captive in each holder by an arrangement of magnetic plates in the holders. However, the magnetic force will be only sufficient to hold the springs lightly in position, and during placement onto the lower web, but will permit the magazine to withdraw each pocket from engagement with the springs as it moves back to its receiving position for a fresh charge of springs to be loaded.

The invention also include an upholstery unit when made by a machine according to the invention.

In a particularly preferred embodiment of upholstery unit according to the invention, the springs which are supplied thereto may comprise "pocketed springs" of the type available with the more expensive type of mattress, in which the pockets are normally supplied in lines of springs which are joined to each other end to end along the line.

The magazine will be suitably adapted to hold a line of pocketed springs, and then this line of springs can be applied between the upper and lower webs in the manner described above. The line of pocketed springs will be securely located in position between the two webs by adhesive engagement therewith, and there will be no necessity for any adhesion to take place between successive lines of pocketed springs which are applied subsequently at required longitudinal spacings along the length of the upholstery unit.

Preferably, the upper and lower webs of material are derived from reel supplies mounted on the machine and permitting controlled withdrawal of the webs of material as the webs are advanced incrementally through the machine.

Conveniently, the web of material forming the upper web is guided from its reel along a guide path which includes a movable guide plate which, in a first position, allows the magazine to deposit the line of springs onto the lower web, and then is movable to a pressing-down position in which the upper web is pressed downwardly onto the upper ends of the springs. One increment of advance then takes place, and then the guide plate returns to its initial position so that a further traverse of the adhesive applicator head can take place, followed by placement of a further line of springs.

The guide plate may therefore extend generally upwardly of the lower web, when in its first position, and thereby defines a support for the face of the upper web while the adhesive applicator head applies the adhesive thereto, this face subsequently facing downwardly upon movement of the guide plate to its pressing-down position.

The guide means for guiding the upper and lower webs to the discharge position may comprise endless conveyors which apply compression to the upper and lower webs with the lines of spring adhering therebetween, and during traverse to the discharge station the adhesive will cure or set, so that by the time a line of a spring reaches the discharge station it will be at least part securely located in position laterally by the adhesive.

When a required length of spring assembly and web has issued from the discharge station, the cutting means may be operated to cut off the upholstery unit. This may comprise a rotary cutter blade which travels transversely of the path of movement of the upholstery unit, though evidently any other suitable cutting means may be adopted.

One embodiment of machine according to the invention will now be described in detail, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a machine for assembling upholstery springs between two sheets of material to form an upholstery unit: Figure 2 is a side view of the machine shown in Figure 1; Figure 3 is a detailed side view of an input station at one end of the machine; and, Figure 4 is an end view of the machine.

Referring now to the drawings, there will be described an embodiment of machine for assembling upholstery springs between two sheets of material to form an upholstery unit, in which the springs are arranged in lines at any required spacing apart from each other along each line, and with the lines of springs being spaced apart along the length of the upholstery unit at any required spacing also.

The machine is designated generally by reference 10 and comprises first and second supply means 11 and 12 in the form of supply reels which supply upper and lower webs of material 13 and 14 to pass through the machine, the webs being intended to form the two sheets of the upholstery unit which will be formed by the machine. Guide means is provided to guide the webs 13 and 14 through the machine along respective spaced apart upper and lower paths, and take the form of a pair of upper and lower endless conveyors 15 and 16. The guide paths extend from an input station 17 at an upstream end to a discharge station 18 at a downstream end of the guide paths.

An adhesive applicator head 19 is mounted at the input station 17 to carry out linear reciprocation in a direction transversely of the path Jf travel of the webs 13 and 14, the head 19 being operable to apply adhesive to the sides of the webs which face each other as they travel to the discharge station 18 between the endless conveyors 15 and 16. The adhesive is ap.plied to the faces of the webs 13 and 14 as shown in Figure 1, which defines lines of adhesive corresponding with the intended placement of a line of springs between the two webs. The adhesive may be applied as continuous jets of hot melt adhesive, or other suitable adhesive material, or may be applied as continuous, semi-continuous, or intermittent blobs of material, according to the required degree of adhesion to the web and to the springs which is required.

A spring loading device 20 (see Figure 3) is mounted at the input station 17 and is operable to hold a line of individual springs and to apply the springs onto the upper side of the lower web 14 after application of adhesive thereto by the applicator head 19 along the required placement line.

It will be noted from Figures 1 and 2 that the upper web 13 passes from its reel 11 over a guide plate 21, and this guide plate is shown in Figure 1 occupying an initial position- in which it acts as a support for the web 13 while adhesive is applied thereto by the head 19. In addition, this leaves free a space into which the spring loading device 20, in the form of a magazine, can pivot so as to unload a line of springs which it holds onto the adhesive which has just been applied by the applicator head 19.

Figure 3 shows the spring loading device 20 in its spring deposition position, and after it has completed this task, it will revert to a horizontal position (not shown) into which it can receive a further load of springs.

Upon completion of the application of lines of adhesive to the upper and lower webs, and the placement of the line of springs on the lower web by the machine 20, the guide plate 21 is then pivoted anti-clockwise from the position shown in Figures 1 and 2 to a substantially horizontal position, and thereby it applies the upper web 13 downwardly onto the upper ends of the springs so that the spring ends become embedded in the adhesive material.

The adhesive deforms to allow entry of the coil ends of the spring into the adhesive, and thereby moulds itself into trough shapes which laterally locate the spring ends.

The webs 13 and 14 are then advanced towards the discharge station by one increment of spring line separation, so that a further line of springs can be assembled. During travel along the guide path between the conveyors 15 and 16, the adhesive progressively cures or sets, so that when an adhesively engaged line of springs issues from the discharge station 18 it will be at least partly located in position.

When a required length of upholstery unit has issued from the discharge station 18, cutting means in the form of a rotary cutter blade 22 is caused to traverse along a line between two lines of springs, thereby forming a predetermined length of upholstery unit composed of a plurality of springs arranged at required spacings apart along individual lines of springs, and with the lines of springs being spaced apart from each other at any required spacing (as determined by the extent of incremental advance) through the length of the upholstery unit.

The springs which will be loaded into the magazine 20 may comprise conventional helical coil springs employed in mattresses, which will be individually loaded in holder pockets provided by the machine, and this may be carried out manually or by automatic supply apparatus. Individual springs may be held captive releasably in the holder pockets by magnetic arrangements.

If an upholstery unit composed of pocketed springs is required, then a line of pocketed springs may be supplied to a suitably adapted magazine 20, and which will be applied adhesively to the upper and lower webs in similar manner to that described above for coil springs 23.

The material from which the webs 13 and 14 are made may take any suitable form, and may comprise non-woven material suitable for forming "insulators" of mattresses, so that the upholstery unit formed by the machine will be further processed to form a final mattress or other padded upholstery unit. However, other material may be provided for the webs 13 and 14, including woven material, webs of plastics material or any other suitable sheet material to form an upholstery unit.

Claims (15)

1. A machine for assembling upholstery springs between two sheets of material to form an upholstery unit, the springs being arranged in lines which are spaced apart throughout the length of the upholstery unit, and the machine comprising: first and second supply means for supplying respective upper and lower webs of material to pass through the machine, said webs being intended to form said two sheets of an upholstery unit:: guide means for guiding said webs through the machine along respective spaced apart upper and lower paths of travel which extend from an input station at an upstream end to a discharge station at a downstream end; an adhesive applicator head mounted at the input station to carry out linear reciprocation in a direction transversely of said paths, said head being operable to apply adhesive to the sides of the webs which face each other as they travel to the discharge station and along lines corresponding with the intended placement of a line of springs between the two webs; a spring loading device mounted at the input station and operable to hold a line of individual springs and to apply the springs onto the upper side of the lower web after application of adhesive thereto along said placement line;; means for applying the upper web onto the upper ends of the springs, after application of adhesive to the upper web; means for advancing the webs with the line of springs therebetween by one increment of spring line separation towards said discharge station so that a further line of springs can be assembled: and, cutting means at the discharge station operable to cut the upper and lower webs between two lines of springs so as to form a required length of upholstery unit composed of a plurality of springs arranged in lines between two sheets of material and spaced apart from each other along the length of the upholstery unit.

2. A machine according to Claim 1, in which the adhesive applicator head is arranged to apply continuous, part continuous, part intermittent supply or intermittent jetting of blobs of adhesive at spacings apart along the placement line to suit the spacing apart of the springs which will be held on the spring loading device.

3. A machine according to Claim 2, in which the adhesive applicator head is arranged to apply discrete portions or blobs of adhesive along two lines on each web, so that the usual circular end of a spring can be pressed into the adhesive before it has set and it is laterally located by moulding itself into the adhesive before the latter had set.

4. A machine according to Claim 1, in which the adhesive applicator head is arranged to apply continuous lines of adhesive to the webs along the initial traverse of the adhesive applicator head from the edges, so that the spring ends which are embedded in these lines can become securely located. by virtue of the impregnation. at least partially, of the lines of adhesive into larger areas of the web material.

5. A machine according to any one of the preceding claims. in which the spring loading device takes the form of a magazine having holders for each spring, which can be loaded manually or by an automatic supply arrangement.

6. A machine according to Claim 5, in which the holders take the form of pockets which are arranged so that the springs can be loaded and held horizontally prior to placement onto the lower web.

7. A machine according to Claim 6, in which the holders have an arrangment of magnetic plates for holding the springs releasably captive in each holder.

8. A machine according to any one of the preceding claims, in which the spring loading device is arranged to be able to hold a line of pocketed springs.

9. A machine according to any one of the preceding claims, in which the first and second supply means comprise means for mounting reel, supplies on the machine and arranged so permit controlled withdrawal of the webs of material as the webs are advanced incrementally through the machine.

10. A machine according to Claim 9, including a guide path for guiding the upper web from its reel, said guide path including a movable guide plate which, in a first position, allows the magazine to deposit the line of springs onto the lower web, and then is movable to a pressing-down position in which the upper web is pressed downwardly onto the upper ends of the springs.

11. A machine according to Claim 10. in which the guide plate extends generally upwardly of the lower web.

when in its first position, and thereby defines a support for the face of the upper web while the adhesive applicator head applies the adhesive thereto, this face subsequently facing dowardly upon movement of the guide plate to its pressing-down position.

12. A machine according to any one of the preceding claims, in which the guide means for guiding the upper and lower webs to the discharge position comprise endless conveyors which apply compression to the upper and lower webs with the lines of spring adhereing therebetween, and during traverse to the discharge station the adhesive can cure or set, so that by the time a line of a spring reaches the discharge station it will be at least part securely located in position laterally by the adhesive.

13. A machine according to any one of the preceding claims. in which the cutting means comprises a rotary cutter blade operable to travel transversely of the path of movement of the upholstery unit.

14. A machine according to Claim 1 and substantially as hereinbefore described with reference to, and as shown in the accompanying drawings.

15. An upholstery unit made by a machine according to any one of the preceding claims.