US3766578A

US3766578A - Coil spring assemblies for furniture

Info

Publication number: US3766578A
Application number: US00269104A
Authority: US
Inventors: J Toupal
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-07-05
Filing date: 1972-07-05
Publication date: 1973-10-23
Anticipated expiration: 1990-10-23

Abstract

Disclosed herein is a furniture spring assembly including a planar wire mesh base that defines an array of nests each of which accommodate a conventional coiled spring with a uniformly curved end loop. Each of the nests include retaining portions which receive the resilient end loops of the coiled springs only after deformation thereof and thereafter permit the loops to nest by springing back into their original shape. Once nested, the end loops are restrained by the retaining portions from movement in all directions establishing a stable unit.

Description

[ Oct. 23, 1973 COIL SPRING ASSEMBLIES FOR FURNITURE Inventor: John E. Toupal, 14 Bear Hill Road,

Primary Examiner-James C. Mitchell 7 Sherborn, Mass. [57] ABSTRACT [22] Filed: July 5, 1972 Mm--1 mA-WM Disclosed herein is a furniture spring assembly includ- [211 AppL No 269 104 ing a planar wire mesh base that defines an array of nests each of which accommodate a conventional coiled spring with a uniformly curved end loop. Each [52] U.S. C1. 5/267, 5/263 of [he nests include retaining portions which receive [51] Int. C1. A476 23/02 the resilient end loops of the coiled springs only after Field Search 265, 266, deformation thereof and thereafter permit the loops to 5/2 nest by springing back into their original shape. Once nested, the end loops are restrained by the retaining References Cited portions from movement in all directions establishing UNITED STATES PATENTS a stable unit.

1,871,440 8/1932 Barnard 5/265 3,267,495 8/1966 Tabor 5/263 25 Clams l0 Drawmg F'gures 3,660,854 5/1972 Garceau 5/267 m. "T F )I )L I II ll 5 I L I W i J l I I6 z E f it Q 1 1 5 z I u flf u u 1 X j A, & 2A 1 |e I I8 l5 Ltd PATENTED OCT 2 3 I975 SHEET 3 BF 3 Fig. 10.

1 con. SPRING ASSEMBLIES FOR FURNITURE BACKGROUND OF THE INVENTION This invention relates generally to coiled spring structures for furniture and specially suited foruse in box springs and inter-springmattresses.

The most common technique for assembling coiled spring structure entails the securement of a plurality of individual coiled springs to a mesh support base formed by interconnected, orthogonally oriented wires. The securement of the individual coils to the mesh base is accomplished in a variety of manners including, for example, the steps of welding, wiretwisting, clipping, etc. Obviously, these methods of securement are time consuming and therefore add substantially to the cost of the finished units. Prior attempts to solve this problem by simplifying the securement process have generally led to end products of reduced stability. Other factors that contribute heavily to the consumer price of coiled spring assemblies are the costs incident to storage and handling of the extremely bulky structures.

Many of these difficulties have been aleviated to some degree by a recently introduced commercial innovation in which the end loops of individual springs are constructed with diametrically opposed bent portions that interlock with accommodating bent portions formed in wires of the mesh base. The dimensions of and spacing between the bent portions are such that they can be engaged initially only after deformation of the end loop. Subsequently, the individual springs are securely retained in position by return of the end loops to their original shape establishing a locking relationship between the accommodating bent portions on both the springs and the mesh base. This technique simplifies the construction of coiled spring assemblies, thereby reducing manufacturing costs as well as facilitating the efficient storage and shipment of the individual components in knocked-down form. Introduced by this technique, however, are new problems incident to the required alteration in the form of the coiled springs. This entails either modification of existing coiled spring manufacturing equipment or an additional manufacturing step to form the bent portions in'the end loops.

The object of this invention, therefore, is to provide an improved coiled spring structure which is both simple to assemble and employs conventional coiled springs.

SUMMARY OF THE INVENTION THis invention is characterized by the provision of a furniture spring assembly including a planar wire mesh base that defines an array of nests each of which accommodates a conventional coiled spring with an end loop of conventional uniform curvature. Each of the nests includes retaining portions which receive and overlay both sides of the resilient end loops of the coiled springs only after deformation thereof and thereafter permit the loops to nest by springing back into their original shapeQOnce nested, the end loops are restrained by the retaining portions from movement in all directions establishing a stable unit.

In preferred embodiments of the invention, the end loop retaining portions include a pair of wire sections each having a planar portion lying in the plane of the mesh base and a displaced portion extending from the planar portion in directions both parallel and perpendicular to that plane. The wire sections are disposed at locations adjacent diametrically opposed positions on the end loop and the displaced portions are separated by a maximum distance greater than the normal diameter of the end loop so as to define a nest that will receive the end loop only after deformation thereof. Once the spring is nested, the planar portions of the wire sections limit movement of the end loop in one direction and the displaced portions limit movement thereof in the opposite direction as well as in directions transverse thereto.

In one form of the above embodiment, the displaced portions are produced by bending the wire sections into ears that extend obliquely from the plane defined by the mesh base. The obliquely bent ears are formed relatively easily and their use therefore facilitates fabrication of the mesh base. In one form of the invention, a pair of planar portions straddle each of the bent ears which extend transversely from the base wires in which they are formed and the individual wire sections of each nest are formed in adjacent parallel wires of the mesh base. This arrangement provides the retained spring with excellent stability by supporting the end loop around a substantial portion of its circumference. In another form, the displaced ears are bent in a direction aligned with the wire in which they are formed and both wire sections of a given nest are formed in the same base wire that passes diametrically over the retained end loop. This arrangement has the advantage of providing an end loop retaining nest with a single base wire thereby reducing to a minimum the requirement for the number of base wires provided in the mesh base. Where additional stability is desired in this arrangement each nest can further include an additional base wire extending diametrically over the retained end loop and orthogonally disposed with respect to the wire in which the wire section ears are formed.

In still another embodiment of this type the bent ears are formed in the shape of a hook into which the end loops are nested. The hook-formed ears offer the advantage of providing camming surfaces which facilitate deformation of the end loops duringtheir assembly into nested position.

In still another embodiment, each wire section of a coil nest comprises a portion of each of three orthogonally intersecting wires in'the mesh base. A parallel pair of the intersecting wires each includes a planar portion while the other wire includes an ear bent downwardly to provide the displaced portion. This arrangement enhances coil stability by establishing extensive contact between the nested end loop and the mesh base.

DESCRIPTION OF THE DRAWINGS These and other objects and features of the invention will become apparent upon a perusal of the following description taken in connection with the accompanying drawings wherein:

FIG. 1 is a schematic illustration partially showing a coiled spring assembly with end loops nested according to the invention;

FIG. 2 is a more detailed view of one of the nested end loops shown in FIG. 1;

FIG. 3 is a cross sectional view taken along lines 3-3 in FIG. 2;

FIG. 4 is a schematic view of a modified nested coil embodiment;

FIG. 5 is a cross sectional view taken along lines 5-5 in FIG. 4;

FIG. 6 is a cross sectional view taken along lines 6-6 in FIG. 4;

FIG. 7 is a schematic view of another nested coil embodiment;

FIG. 8 is a cross sectional view taken along lines 8-8 in FIG. 7;

FIG. 9 is a schematic view of another nested coil embodiment; and

FIG. 10 is a cross sectional view taken along lines 10-10 in FIG. 9.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIG. 1 there is shown in schematic form a portion of a spring assembly 11 constructed according to the present invention. The assembly 11 includes a mesh base 12 formed by a first set of parallel spaced apart wires 13 and a second set of spaced apart parallel wires 14 orthogonally disposed with respect to the wires 13. A frame 15 supports the ends of the

wires

13 and 14 which are attached at their intersections 16 by welds, for example, so as to provide a dimensionally stable base. The frame 15 and the mesh 12 formed by the

wires

13 and 14 lie in a plane that establishes the top surface of the assembly 11 which is specifically suited for use in a box spring or interspring mattress. Defined by the mesh base 12 is an array of nests each of which receive and retain the larger diameter, more flexible end loop 18 of a conventional helically coiled spring formed from resilient, deformable wire and also having at its opposite end a stiffer smaller diameter end loop (not shown). As shown, the coiled spring nests for the embodiment of FIG. 1 are located at the intersections 16 of the

base wires

13 and 14.

Prior to assembly of the unit 11, the base 12 and the individual coiled springs can be shipped efficiently in knocked-down form and then assembled at a point of final distribution. As described in detail below, the individual end loops 18 of the coiled springs are secured to the mesh base 12 in a simple manner and without any requirement for wire twisting, clipping welding, etc. After the top end loops 18 have been secured to the mesh base 12 the opposite or bottom ends (not shown) of the coiled springs are fixed to a suitable support such as a box frame (not shown) according to any of various well known techniques, one example of which is disclosed in US. Pat. No. 3,414,915. The present invention simplifies the construction of assemblies with different numbers of individual springs which in turn establish the firmness of the ultimate unit. As illustrated by dotted lines in FIG. 1, additional springs 18' can be secured into existing nests when additional firmness is desired. It will be obvious that the mesh bases 12 can be produced and supplied either as a standard unit possessing the minimum number of nests required for a desired maximum firmness or as custom units each possessing a different number of nests associated with a particular degree of firmness. The first approach has the advantage of simplifying manufacture, stocking and distribution of the mesh bases 12 while the second method has the obvious advantage of utilizing a minimum number of

base wires

13 and 14 for each type of finally assembled spring unit 11.

Referring now to FIGS. 2 and 3 there is shown in greater detail one of the nested end loops 18 shown in FIG. 1. As illustrated, the rectilinear wires 13 are secured by welds to the orthogonally disposed rectilinear wires 14 at their intersections 16. The wires 14 include spring retaining portions formed by

wire sections

21 and 21 located adjacent diametrically opposed positions on the end loop 18 which has in the conventional manner a uniform sense of curvature as shown. Each of the

wire sections

21 and 21 includes a

planar portion

22 and 22, respectively, lying parallel to the loop 18 in the plane defined by the mesh base 12 and a displaced portion 23 and 23', respectively, formed by a bent ear in the wire 14. As shown most clearly in FIG. 3 the displaced

portions

23 and 23 are bent obliquely to the loop 18 so as to extend from the

planar portions

22 and 22 in directions a that are perpendicular to loop 18 and in directions b that are parallel thereto. Thus, the planar portions 22 and 22' overlay one side of the loop 18 and the displaced

portions

23 and 23 underlay the opposite side thereof. It will be noted in FIG. 3 that the parallel displacements in directions b provide a maximum separation between the displaced ears 23 and 23' that is greater than the normal diameter of the end loop 18. Accordingly, the resilient loop 18 can be positioned in the

nest

24 and 24 only after being deformed as shown by dotted lines in FIGS. 2 and 3. This deformation enlarges the end loop 18 in the direction of separation between the ears 23 and 23' allowing the loop 18 to be passed thereover. After release of the loop 18, its resilient characteristics cause it to spring back toward its original shape within the

nest

24 and 24. In that nested position the planar portions 22 and 22' of

wire sections

21 and 21 overlay one side of the loop 18 so as to limit upward movement thereof (as seen in FIG. 3) while the displaced loop portions 23 and 23' underlay the opposite side thereof to limit movement in a downward direction as well as in directions transverse to the plane defined by the

wires

13 and 14.

The wire 13 further stabilizes the nested spring by engaging the end loop 18 at positions displaced 90 from the wire sections 21. However, as described above, the loop 18 is fully retained by the diametrically

opposed wire sections

21 and 21. Therefore, in some applications, individual springs can be retained solely by a wire 14 with retaining portions 21 and 21' and without the requirement for a transverse wire 13 as indicated by the additional coils 18 shown dotted in FIG. 1. In that case, only as many transverse wires 13 as are desired to establish dimensional stability for the mesh base 12 need be employed and the overall requirement for wire is thereby minimized.

Referring now to FIGS. 4-6 there is shown another spring assembly embodiment 31. Again, orthogonally related intersecting wires 32 and 33 (only two of which are shown) establish a planar mesh base 34 similar to the mesh base 12 shown in FIG. 1. As in that embodiment, the base mesh 34 defines an array of nests for retaining individual end loops 35 (only one of which is partially shown) of conventional coiled springs. Each nest has retaining portions including a pair of

wire sections

36 and 36 disposed adjacent diametrically opposed positions on the end loop 35. As in the embodiment shown in FIGS. 2 and 3, the wire sections 36 and 36' each possess a planar portion 37 and 37' respectively, lying in the plane defined by the mesh base 34 and a displaced

portion

38 and 38, respectively, formed by a bent ear in the wire 32. The separation be tween the

bent ears

38 and 38 again is greater than the normal diameter of the end loop 35 which must be deformed as shown by the dotted lines to enter the nest 39 and 39'. Once nested, movement of the end loop 35 is limited an upward direction (as seen in FIG. 5) by the planar portions 37 and 37' that overlay one side of the loop 35 and in both downward and transverse directions by the displaced portions 38 and 38' that underlay the opposite side thereof. Further stability is again provided by engagement between the transverse wires 33 and positions on the end loop 35 located 90 from the

wire sections

36 and 36. An advantage of the hook shape provided by the change of direction in the bent ears 38 and 38' is that the end loop is more securely retained. Furthermore, the upwardly sloping outer portion of the hooked ears 38 and 38' provide camming surfaces that facilitate deformation of the end loops 35 during assembly. Forcing the end loop 35 against one of the cam surfaces 40 or 40' tends naturally to deform the end loop 35 and facilitate its entry into the nests 39 and 39'. I

Again, the displaced

hook portions

38 and 38 extend from the planar portion 37 and 37' in a direction a perpendicular to the end loop 35 and in a direction b parallel thereto. Also, as in the embodimentof FIGS. 2 and 3,complete support of the end loop is provided by a single wire 32 having spaced'apart retaining wire sections. To facilitate this arrangement it will be noted that the displacement of the

ears

38 and 38 in directions b parallel to the mesh base again are aligned with the wires in which the wire sections, are formed.

Referring now to FIGS. 7 and 8 there is shown another nested spring embodiment 51. Again a mesh base 52 provides an array of nests for end loops 53 (only one of which is partially shown) of conventional coiled springs. The planar mesh base 52 is formed by a first set of spaced apart parallel wires 54 connected, for example by welds, at intersections 55 with another orthogonal set of wires 56. In this embodiment, the retaining portions of each nest'are formed in a pair of adjacent parallel wires 54 of the base 52. As shown, each wire 54 includes a wire section 57 located adjacent diametrically opposed positions on the end loop 53. Each of the wire sections 57 comprise a displaced portion 58 straddled by planar portions 59. Again, the displaced portions 58 are formed by ears bent obliquely with respect to the plane of the base mesh 52 and include terminal portions spaced apart a greater distance than the normal diameter of the end loop 53. Also, the displaced ear portions 58 again extend from the planar portions 59 in directions a (shown in FIG. 8) perpendicular to the end loop 53 and in directions 0 (shown in FIG. 7) parallel thereto so as to underlay opposite sides thereof. However, in this embodiment the latter direction is transverse to the bent wire rather than aligned therewith.

As above, the embodiment 51 is assembled by deforming the resilient end loops 53 allowing them to pass over the terminal portions of the displaced ears 58. The end loops are then allowed to spring back into nesting relationship within the nests 61 wherein their upward movement (as seen in FIG. 8) is limited by the planar portions 59 and downward movement as well as transverse movement is limited by the displaced ear portions 58. The orthogonally disposed wires 56 are not required for nesting and their number and location is determined by the degree of dimensional stability desired of the mesh base 52. However, if additional support is desired for individual coiled springs, a pair of orthogonally disposed wires 56 can be positioned over edges of the end loop 53 spaced from the portions retained by the wire sections 57 (as shown by dotted lines in FIG. 7). In that case, the displacement of the bent ears 58 in direction a (FIG. 8) must be slightly greater to provide space for the wires 56 between the wires 54 and the end loop 53.

Referring now to FIGS. 9 and 10 there is shown still another nested coil embodiment 61 including a mesh base 62 that provides an array of nests for end loops 63 (only one of which is partially shown) of conventional coiled springs. Again, the mesh base 62 is formed by a first set of spaced apart parallel wires 63' fixed, for example by welding, at intersections 64 with a second set of orthogonally disposed parallel wires 65. Each nest includes coil retaining portions formed by diametrically opposed wire sections 66 that serve to retain the end loops 63 in place. Each wire section 66 includes planar portions 67 that straddle a displaced portion 68. As in all previous embodiments, the planar portions lie parallel to the loop 63 on one side thereof in the plane defined by the mesh base 62, while the displaced portions 68 extend from the planar portions both in directions e (shown in FIG. 9) parallel to said loop 63 and in directions f (shown in FIG. 10) perpendicular thereto so as to underlay the opposite side thereof. However, in

this case the displaced portions 68 formed by bends in the wires 65 are separated by a distance less than the normal diameter of the end loop 63. Nevertheless, as shown with dotted lines in FIG. 9, the end loop 63 must again be deformed to allow its access into the nesting regions 69 where it nests by springing back into original shape. In this case, however, the loop 63 is contracted in the direction of separation between the displaced portions 68. Once nested the planar portions 67 limit upward movement (as shown in FIG. 10) of the end loop 63 while the displaced portions 68 limit downward and transverse movement thereof.

Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is to be understood, therefore, that the invention can be practiced otherwise than as specifically described.

What is claimed is: v

1. A furniture spring assembly comprising: a mesh base, said base defining an array of nests, a plurality of helically coiled springs each having a relatively stiff small diameter end loop and a resilient deformable larger diameter end loop nested in a different one of said nests, each of said nests comprising a plurality of retaining portions each of which restrict movement of said nested loop, at least one of said retaining portions engaging said nested loop along an arc thereof having a uniform sense of curvature, and wherein said nests are dimensioned so as to receive said larger end loops only after deformation thereof and to thereafter permit said larger end loops to nest by movement toward their original shapes.

2. An assembly according to claim 1 wherein said larger end loops have a continuously uniform sense of curvature.

3. An assembly according to claim 2 wherein said mesh base is substantially planar, said larger end loops are retained in positions substantially parallel to the plane of said mesh base, and said retaining portions limit the movement of said nested loop in opposite directions perpendicular to said plane.

4. An assembly according to claim 2 wherein said mesh base comprises intersecting wires arranged in an orthogonal pattern and fixed to each other at points of intersection.

5. An assembly according to claim 2 wherein each of said retaining portions comprises a wire section having a planar portion and a displaced portion, said planar portion being substantially parallel to said larger loop and said displaced portion extending from said planar portion in directions having components both parallel and perpendicular to said larger loop, and wherein said planar portion overlays one side of said nested larger loop said displaced portion overlays the opposite side of said larger loop.

6. An assembly according to claim 5 wherein each of said nests comprises a pair of said displaced portions located adjacent opposed positions on said loop and having loop obstructing portions separated by a distance greater than the normal spacing between said opposed positions on said loop.

7. An assembly according to claim 5 wherein each of said nests comprises a pair of said displaced portions located adjacent opposed positions on said loop and having loop obstructing portions separated by a distance less than the normal spacing between said opposed positions on said loop.

8. An assembly according to claim 5 wherein each of said nests comprises a pair of said wire sections disposed at locations adjacent diametrically opposed positions on said larger loop.

9. An assembly according to claim 8 wherein said displaced portions extend from said planar portions in directions having components parallel thereto.

10. An assembly according to claim 8 wherein said displaced portions extend from said planar portions in directions having components perpendicular to said larger loops and toward the ends of said coiled springs opposite said end larger loops.

11. An assembly according to claim 8 wherein said displaced portions extend from said planar portions in directions having components transverse thereto.

12. An assembly according to claim 11 wherein each said wire section comprises orthogonally intersecting wires fixed together at their points of intersection, one of said intersecting wires forming said planar portion and said other intersecting wire being bent to form said displaced portion.

l3. An assembly according to claim 5 wherein said displaced portions comprise bent ear portions of said wire sections.

14. An assembly according to claim 13 wherein said bent ear portions extend obliquely from said larger loop.

15. An assembly according to claim 13 wherein said bent ear portions extend transversely to said planar portions.

16. An assembly according to claim 13 wherein said bent ear portions extend parallel to said planar portions.

17. An assembly according to claim 13 wherein said bent ear portions extend toward the ends of said coiled springs opposite said end larger loops.

18. A furniture spring assembly comprising: a mesh base, said mesh base formed by intersecting wires attached together at points of intersection, said base defining an array of nests, a plurality of helically coiled springs each having a relatively stiff small diameter end loop and a resilient deformable larger diameter end loop disposed substantially parallel to said base and nested in a different one of said nests, each of said nests comprising a pair of retaining portions each of which restrict movement of said nested loop in opposite directions, said pair of retaining portions being disposed on one of said wires and engaging spaced apart positions on said loop, and wherein said nests are dimensioned so as to receive said loops only after deformation thereof and to thereafter permit said loops to nest by movement toward their original shapes.

19. An assembly according to claim 18 wherein said pair of retaining portions engage diametrically opposed positions on said larger loop.

20. An assembly according to claim 19 wherein each of said nests comprises another of said wires transverse to said one wire and overlaying a substantial arc of said larger loop.

21. An assembly according to claim 20 wherein said another of said wires passes diametrically over said larger loop.

22. An assembly according to claim 18 wherein each of said retaining portions comprises a wire section having a planar portion and a displaced portion, said pla nar portion being substantially parallel to said larger loop and said displaced portion extending from said planar portion in directions having components both parallel and perpendicular to said larger loop, and wherein said planar portion overlays one side of said nested larger loop said displaced portion underlays the opposite side of said larger loop.

23. An assembly according to claim 22 wherein said pair of displaced portions on said one wire have larger loop obstructing portions separated by a distance greater than the normal spacing between said spaced apart positions on said larger loop.

24. An assembly according to claim 23 wherein said displaced portions comprise bent ear portions of said wire sections.

25. An assembly according to claim 24 wherein said bent ear portions extend parallel to said planar portions.

Claims

13. An assembly according to claim 5 whereiN said displaced portions comprise bent ear portions of said wire sections.

22. An assembly according to claim 18 wherein each of said retaining portions comprises a wire section having a planar portion and a displaced portion, said planar portion being substantially parallel to said larger loop and said displaced portion extending from said planar portion in directions having components both parallel and perpendicular to said larger loop, and wherein said planar portion overlays one side of said nested larger loop said displaced portion underlays the opposite side of said larger loop.