Title:
Furniture spring support system restrictor wire
Kind Code:
A1


Abstract:
A deflection limitation system for upholstered furniture seat members includes a rectangular-shaped support frame having opposed front and rear members and opposed sides. Sinuous-shaped springs are connected to both the front and rear members. Each spring is deflectable over a limited range defined between a non-deflected position and a maximum deflected position. A wire element crossing below the spring elements has ends each connected to different frame sides. A central portion of the wire element is downwardly curved. A predefined spacing separates the wire element central portion from each of the spring elements in the non-deflected position. The maximum deflected position of the spring elements wherein the spring elements contact the central portion of the wire element is reached when a predefined load is distributed to the spring elements. The spring elements are thereafter restrained from further deflection by the wire element.



Inventors:
Mohn, Michael E. (Monroe, MI, US)
Mcclung, Mark D. (Grandview, TN, US)
Lapointe, Larry P. (Temperance, MI, US)
Application Number:
11/046579
Publication Date:
08/03/2006
Filing Date:
01/28/2005
Primary Class:
International Classes:
A47C7/02
View Patent Images:
Related US Applications:
20080018152Collapsible Portable Child Safety SeatJanuary, 2008Vadai
20090236895Furniture construction with tensioned fabricSeptember, 2009Bottemiller
20070007802Seat caddy having a single adjustment pointJanuary, 2007Kelleher
20080061618Exercise Cushion And Uses ThereofMarch, 2008Desimone Lavigne
20070035165SEAT TRIM COVER ATTACHMENT COMPONENT AND RELATED METHODFebruary, 2007Zahel
20040174050Chair with manually-adjustable mirrorSeptember, 2004Raquet
20070096524Corrective chairMay, 2007Chou
20090243345Universal hunting swivel chairOctober, 2009Carter et al.
20090224591Accessory Footrest AttachmentSeptember, 2009Langhorn
20090174234EXPANSION AND RETRACTION MECHANISMS FOR MOVEABLE TRAY TABLESJuly, 2009Vignal et al.
20020060483Safety device for car seatMay, 2002Yoshida et al.



Primary Examiner:
HSIAO, JAMES K
Attorney, Agent or Firm:
HARNESS DICKEY (TROY) (Troy, MI, US)
Claims:
What is claimed is:

1. A furniture structural support system, comprising: a frame; a plurality of biasing elements connected to the frame, the biasing elements being each deflectable over a limited range defined between a non-deflected position and a maximum deflected position; and a restrictor element overlapping each of the biasing elements, the restrictor element including opposed ends each connected to the frame; wherein a predefined load distributed to the biasing elements is operable to deflect the biasing elements to the maximum deflected position defined as the biasing elements being in contact with the restrictor element, the biasing elements being thereafter restrained from further deflection by the restrictor element.

2. The system of claim 1, further comprising a clearance gap created between the central portion of the restrictor element and each of the biasing elements in the non-deflected position.

3. The system of claim 2, wherein each of the spring elements further comprises: a longitudinal axis; and opposed ends; wherein the longitudinal axes of the biasing elements are arranged substantially parallel with each other.

4. The system of claim 3, further comprising: a substantially rectangular frame shape having sides defining a first opposed pair and a second opposed pair of sides; and a plurality of connectors operable to fasten the opposed ends of the biasing elements to each side of the first opposed pair of sides; wherein the opposed ends of the restrictor element are connectable to opposite ones of the second opposed pair of sides, the restrictor element being substantially perpendicular to the longitudinal axes of the biasing elements.

5. The system of claim 4, wherein each of the opposed ends of the restrictor element are connected at a mid-span position of each frame side of the second opposed pair of sides.

6. The system of claim 4, wherein the frame comprises a wood material.

7. The system of claim 6, further comprising a contact plate disposed between each of the opposed ends of the restrictor element and the frame.

8. The system of claim 1, further comprising at least one stiffening member connected to each of the biasing elements and arranged substantially perpendicular to the longitudinal axes of the biasing elements.

9. The system of claim 1, wherein each of the biasing elements comprises a sinuous type spring.

10. A furniture structural support system, comprising: a rectangular-shaped support frame having opposed front and rear members and opposed sides; a plurality of sinuous-shaped springs connected to both the front and rear members, each spring being deflectable over a limited range defined between a non-deflected position and a maximum deflected position; a wire element crossing below the spring elements, the wire element including: opposed ends each connected to different ones of the opposed sides of the frame; a central portion defining a curve between the opposed ends; and a clearance gap created between the central portion of the wire element and each of the spring elements in the non-deflected position; wherein the maximum deflected position of the spring elements having the spring elements in contact with the central portion of the wire element is reached when a predefined load is distributed to the spring elements, the spring elements being thereafter restrained from further deflection by the wire element.

11. The system of claim 10, further comprising an upholstered element connected to the spring elements.

12. The system of claim 11, further comprising a cloth element positioned between the upholstered element and the spring elements.

13. The system of claim 11, wherein the upholstered element comprises a seat cushion, the wire element being positioned generally below the spring elements and the seat cushion.

14. The system of claim 10, wherein the predefined load comprises an occupant weight of at least 400 pounds.

15. The system of claim 10, wherein the predefined load comprises an occupant weight of at least 500 pounds.

16. The system of claim 10, further comprising at least one stiffening member connected to each of the spring elements and arranged substantially perpendicular to the longitudinal axes of the spring elements.

17. The system of claim 10, further comprising a plurality of connectors operable to fasten the opposed ends of the spring elements to each side of the first opposed pair of sides.

18. A seating frame suspension assembly, comprising: a frame including connected elements defining a frame outer perimeter; a plurality of spring elements substantially positioned within the outer perimeter of the frame and each connected to the frame, the spring elements being each deflectable over a limited range varying between a non-deflected position and a maximum deflected position; an upholstered element connected to the spring elements; and a support element transversely crossing each of the spring elements, the support element including: opposed ends each connected to the frame; and a central portion defining a curve between the opposed ends; wherein a predefined load distributed to the spring elements through the upholstered element is operable to deflect the spring elements to the maximum deflected position defined as the spring elements being in contact with the central portion of the support element, the spring elements being thereafter restrained from further deflection by the support element.

19. The suspension assembly of claim 18, further comprising a predefined spacing separating the central portion of the wire element from each of the spring elements in the non-deflected position.

20. The suspension assembly of claim 19, further comprising a contact plate disposed at the frame adjacent each of the opposed ends of the restrictor element.

21. The suspension assembly of claim 18, wherein each of the spring elements further comprises a sinuous wire spring.

22. The suspension assembly of claim 18, wherein each of the connected elements of the frame further comprises a top surface supporting one of the spring elements and one of the opposed ends of the support element.

23. The suspension assembly of claim 18, wherein the frame further comprises opposed front and rear members, the spring elements being supported from the front and rear members.

24. The suspension assembly of claim 18, wherein the frame further comprises opposed side members, the opposed ends of the support element being connected to one of the side members.

25. A seat assembly, comprising: a frame including a front rail, a rear rail and two opposing side rails, each of the rails having a top edge; a plurality of substantially parallel sinuous wire springs traversing the frame between the front and rear rails, the sinuous wire springs including first and second attachment ends connectable to the top edges of the front and rear rails, respectively; at least one stabilizer wire extending substantially perpendicular to the sinuous wire springs and connected to each of the sinuous wire springs; and a restrictor wire having opposed connecting ends, each connecting end connected to the top edge of one of the side rails, the restrictor wire having an arc-shaped central portion between the connecting ends operable to space the central portion from each of the sinuous wire springs in a non-deflected position of the sinuous wire springs.

26. The seat assembly of claim 25, wherein a maximum deflection position of the sinuous wire springs is reached when the sinuous wire springs contact the arc-shaped central portion of the restrictor wire.

27. The seat assembly of claim 26, further comprising a predetermined load applied to the sinuous wire springs operable to deflect the sinuous wire springs to the maximum deflection position.

28. The seat assembly of claim 27, wherein the predetermined load is at least 400 pounds.

29. The seat assembly of claim 27, wherein the predetermined load is approximately 500 pounds.

30. The seat assembly of claim 25, wherein the connecting ends of the restrictor wire further comprise: a hooked free end; and a bend area; wherein the hooked free end is received within the side rail and the bend area operably contacts the top edge of the side rail.

31. The seat assembly of claim 30, further comprising an aperture created on the top edge of each side rail operable to receive the hooked free end of the restrictor wire.

32. The seat assembly of claim 25, further comprising a loaded condition of the seat assembly wherein a load applied to the sinuous wire springs is operable to deflect the sinuous wire springs from the non-deflected position but insufficient to deflect the sinuous wire springs to the maximum deflection position.

33. The seat assembly of claim 25, further comprising a contact plate positioned on each of the top edges of the side rails, each contact plate having an aperture to receive one of the opposed connecting ends of the restrictor wire.

34. A method for restricting a seating assembly spring deflection, the seating frame including a frame, a plurality of spring elements connected to the frame, an upholstered element connected to the spring elements, and a restrictor element transversely crossing each of the spring elements, the method comprising: creating a geometrically-shaped body of the restrictor element; positioning the geometrically-shaped body of the restrictor element below and spatially separated from each of the spring elements in an unloaded condition of the spring elements; applying a load to the upholstered element distributable to each of the spring elements operable to deflect the spring elements; and limiting a deflection of the spring elements to a contact position of each spring element with the geometrically-shaped body of the restrictor element.

35. The method of claim 34, further comprising predetermining a maximum value of the load.

36. The method of claim 35, further comprising: determining a maximum deflection value of the spring elements corresponding to the maximum value of the load; dimensionally sizing the body of the restrictor element to initially offset the body from the spring elements by the maximum deflection value to operably establish the contact position.

37. The method of claim 34, further comprising forming the geometrically-shaped body as an arc.

Description:

FIELD OF THE INVENTION

The present invention relates in general to furniture support assemblies and more specifically to a wire constructed sprung seat assembly.

BACKGROUND OF THE INVENTION

Furniture and seat cushions are commonly provided with spring support systems which allow the weight of an occupant to deflect the cushion without damage to the cushion, to provide a comfortable feel and to return the cushion to its initial position when unoccupied. Sinuous wire support systems are currently popular for seat and furniture cushions because they provide adequate support while reducing the cost of previously used coil spring support systems.

Sinuous wire springs form a sinuous or zig-zag shaped pattern and are commonly supported at opposed ends to a furniture support frame. The frame is typically a wooden, generally rectangular-shaped structure having front and rear rails and opposed side rails. The sinuous wire springs are therefore supported only at their ends and allow deflection of the furniture cushion in between the frame members. Stiffening members can also be used which are connected generally transversely to the longitudinal axes of the sinuous springs. The stiffening members maintain a spacing of the sinuous springs to help control total deflection and spring shape.

Several disadvantages of common sinuous spring systems are evident when known support systems are used by heavy patrons. Sinuous spring systems generally allow excessive deflection or travel when a heavier patron uses the system than the spring travel is designed for, or when a user such as a child bounces on the cushions. Heavier patrons are herein defined as people exceeding 400 pounds and generally heavier than 500 pounds. Excessive travel from a greater than 400 pound load applied to a cushion can permanently deflect the springs, damage the cushion and/or leave a permanent contour in the cushion. The quantity or size of the springs can be increased to support the greater load, but this both increases cost and provides a generally stiffer feel for lighter users. Stiffening members now provided can be made strong enough to bear this load if connected to the frame, but generally are not connected at their ends to the frame because this prevents spring travel, producing user contact with the stiffening member(s) and therefore reducing comfort and/or damaging the cushion or support system. Spring systems which combine sinuous and coiled springs can also be used, however, increased cost and system complexity result from such a system.

SUMMARY OF THE INVENTION

According to a preferred embodiment of the present invention a furniture spring support system restrictor wire is provided for a system having a frame and a plurality of biasing elements connected to the frame. The biasing elements are each deflectable over a limited range defined between a non-deflected position and a maximum deflected position. A restrictor element overlaps each of the biasing elements. The restrictor element includes opposed ends each connected to the frame and a central curved portion between the opposed ends. A predefined load distributed to the biasing elements deflects the biasing elements to the maximum deflected position defined as the biasing elements being in contact with the central portion of the restrictor element. The biasing elements are thereafter restrained from further deflection by the restrictor element.

According to another preferred embodiment of the present invention, a deflection limitation system for upholstered furniture seat members includes a rectangular-shaped support frame having opposed front and rear members and opposed sides. Sinuous-shaped springs are connected to both the front and rear members. Each spring is deflectable over a limited range defined between a non-deflected position and a maximum deflected position. A wire element crossing below the spring elements has ends each connected to different frame sides. A central portion of the wire element is downwardly curved. A predefined spacing separates the wire element central portion from each of the spring elements in the non-deflected position. The maximum deflected position of the spring elements wherein the spring elements contact the central portion of the wire element is reached when a predefined load is distributed to the spring elements. The spring elements are thereafter restrained from further deflection by the wire element.

According to still another preferred embodiment of the present invention, a seating frame suspension assembly further includes an upholstered element connected to a plurality of spring elements. A support element transversely crosses each of the spring elements. The support element includes opposed ends each connected to the frame, and a central portion defining a curve between the opposed ends. A predefined load distributed to the spring elements through the upholstered element deflects the spring elements to the maximum deflected position defined as the spring elements being in contact with the central portion of the support element. The spring elements are thereafter restrained from further deflection by the support element.

In yet still another preferred embodiment, a seat assembly includes a frame having a front rail, a rear rail and two opposing side rails, each of the rails having a top edge. A plurality of substantially parallel sinuous wire springs traverse the frame between the front and rear rails. The sinuous wire springs include first and second attachment ends connectable to the top edges of the front and rear rails, respectively. At least one stabilizer wire extends substantially perpendicular to the sinuous wire springs and is connected to each of the sinuous wire springs. A restrictor wire has opposed connecting ends, each connected to the top edge of one of the side rails. The restrictor wire also has an arc-shaped central portion between the connecting ends to space the central portion from each of the sinuous wire springs in a non-deflected position of the sinuous wire springs.

In yet another preferred embodiment, a method for restricting a seating assembly spring deflection is provided. The seating frame includes a frame, a plurality of spring elements connected to the frame, an upholstered element connected to the spring elements, and a restrictor element transversely crossing each of the spring elements. The method includes creating a geometrically-shaped body of the restrictor element. The geometrically-shaped body of the restrictor element is positioned below and spatially separated from each of the spring elements. A load is applied to the upholstered element distributable to each of the spring elements and operable to deflect the spring elements. A deflection of the spring elements is limited to a contact position of each spring element with the geometrically-shaped body of the restrictor element.

A furniture support system restrictor wire of the present invention provides several advantages. A restrictor wire of the present invention is easily manufactured and is less expensive than additional sinuous or coiled springs. By predetermining a maximum allowable load or deflection of the sinuous spring system, the restrictor wire can be dimensioned and its wire size selected appropriately to act as a deflection limiter for the sinuous wire springs. By placing a restrictor wire of the present invention below and generally transverse to the axes of the sinuous springs, a normal clearance is provided to allow limited travel of the springs. When the predetermined load is reached the springs contact the restrictor wire and deflection is thereafter restricted. This prevents damage to the springs or the cushion while accommodating heavy patrons with a low cost alternative to more complex spring systems. Bent or hooked ends of the restrictor wire are received in frame members which are positioned transverse to the members supporting the sinuous springs which also distributes cushion loading to alternate frame members.

Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating specific embodiments of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:

FIG. 1 is a perspective view showing an underside of a furniture support assembly restrictor wire of the present invention;

FIG. 2 is a plan view looking down of the furniture support assembly of FIG. 1;

FIG. 3 is a perspective view showing an upper side of a furniture support assembly restrictor wire of the present invention;

FIG. 4 is a side elevational view of a frame for the furniture support assembly FIG. 2;

FIG. 5 is a front elevational view of a restrictor wire of the present invention prior to installation;

FIG. 6 is a front elevational view of the restrictor wire of FIG. 5 following bending during installation;

FIG. 7 is a front elevational view of an alternate embodiment of a restrictor wire of the present invention;

FIG. 8 is a front elevational view of another alternate embodiment of a restrictor wire of the present invention; and

FIG. 9 is a cross-sectional front elevation view taken at section 9 of FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.

According to a preferred embodiment of the present invention and referring generally to FIG. 1, a support assembly 10 incorporating a furniture spring support system restrictor wire of the present invention is shown. Support assembly 10 includes a frame 12 having a front rail 14, a rear rail 15, a first side rail 16, and a second side rail 18. In this embodiment, first and second side rails 16, 18 are substantially parallel with each other and substantially perpendicular to both front and rear rails 14,15, respectively. A furniture member such as a cushion 20 is partially supported on its underside by frame 12 and is deflectable within an envelope of frame 12 by a plurality of sinuous-shaped biasing members 22. In one preferred embodiment of the present invention, biasing members 22 are sinuous-shaped wire springs formed of a spring steel, but can also be constructed from a polymeric or alternate material applicable for use as spring material.

As further shown in FIG. 1, a quantity of five biasing members 22 are arranged in parallel with each other and supported by each of the front and rear rails 14, 15, respectively. One or more stiffening members 24 are orthogonally positioned with respect to the biasing members 22 and connected to each of the biasing members 22. Stiffening members 24 maintain a substantially constant spacing between biasing members 22 as the biasing members deflect and provide additional stiffness to the overall assembly of biasing members 22. One preferred material for stiffening members 24 is spring steel, however other metals, or polymeric or composite material can be used for this application. The invention is not limited by the design or shape of biasing members 22 or stiffening members 24. Alternate designs and shapes of biasing members can also be used such as hybrid seat suspensions, engineered fabric decking materials, composite or coiled springs, etc. The design and shape of stiffening members 24 can also vary depending on the design and shape of biasing members 22.

At least one restrictor element 26 is connected to each of the first and second side rails 16, 18, respectively, oriented substantially transverse to the parallel configured biasing members 22 and therefore substantially parallel to the stiffening members 22. Biasing members 22 are generally positioned in contact with cushion 20, and a liner such as a cloth material is provided between biasing members 22 and cushion 20 to reduce frictional wear to cushion 20 when biasing members 22 deflect upon loading. The position of cushion 20 in FIG. 1 represents an unloaded condition of biasing members 22 wherein a clearance dimension 27 is provided between each of the biasing members 22 and restrictor element 26. In the embodiment shown, restrictor element 26 is formed having an arc-shaped body between oppositely positioned connecting ends, the connecting ends engaging first and second side rails 16, 18. It is noted that clearance dimension 27 can either be equivalent or can vary between individual biasing members 22 and restrictor element(s) 26 due to the geometric shape selected for restrictor element 26.

In one aspect of the invention, a maximum deflected condition for cushion 20 is established when the biasing members 22 deflected by a load applied to cushion 20 and/or directly to biasing members 22 contact restrictor element 26. Restrictor element 26 thereafter restricts further deflection of biasing members 22. Further minor deflection of restrictor element 26 can occur from an increasing load applied to cushion 20 and/or biasing members 22, however this deflection does not significantly affect the maximum deflected condition up to a yield strength of the material of restrictor element 26.

Referring now to FIG. 2, first and second exemplary ones of biasing members 22, identified as biasing members 22′ and 22″, each include a longitudinal axis 28, 29 respectively. A spacing “S” is established between longitudinal axes 28 and 29. According to one aspect of the invention, spacing “S” is maintained between any adjacent pair of biasing members 22. The invention is not limited to a fixed spacing “S”, however. At the designer's discretion, spacing “S” can vary between any two adjacent biasing members 22.

Each of the biasing members 22 includes a first attachment end 30 connected by a first clip 32 to an upper surface 34 of front rail 14. Similarly, each biasing member 22 also includes a second attachment end 36 connected by a second clip 38 to an upper surface 40 of rear rail 15. In the embodiment shown in FIG. 2, reference to upper surfaces refers to surfaces facing the viewer. Each of the stiffening members 24 are connected to each of the biasing members 22 using a connector 42. Use of connectors 42 therefore also establishes spacing “S”. In the embodiment shown, a single restrictor element 26 is connected at both an upper surface 44 and an upper surface 46 of first and second side rails 16, 18, respectively. First and second contact plates 48, 50 are connected to upper surfaces 44, 46, respectively. First and second contact plates 48, 50 maintain engagement of restrictor element 26 with each of first and second side rails 16, 18. In one preferred embodiment, material for frame 12 is selected from a wood material which does not exhibit the material strength properties of, for example, a spring steel material for the restrictor element 26. First and second contact plates 48, 50 therefore help distribute the load from the biasing members 22 through restrictor element(s) 26 to the first and second side rails 16, 18 of frame 12. An aperture 52 is formed in each of first and second contact plates 48, 50 which receives the connecting ends of restrictor element 26. A plurality of fasteners 54 connect first and second contact plates 48, 50 to each of first and second side rails 16, 18 respectively. Other methods to fasten restrictor elements 26 include screw fasteners for attachment, stapling, etc. Material for restrictor element(s) 26 of the present invention can be provided of spring or similar steel, or alternate materials including, but not limited to non-stretchable engineered fabric that provides a center arc to limit the suspension from excessive travel, polymeric or composite materials.

Referring generally to FIG. 3, frame 12 includes an overall length “A” and a width “B”. For purposes of determining an overall deflection of the biasing members 22, an exemplary load “L” is approximately centrally applied to support assembly 10. Load “L” is a predetermined load which in a preferred embodiment of the present invention is at least 400 pounds and preferably approximately 500 pounds. Predetermined load “L” is established by the manufacturer and generally represents a weight of a “heavy” occupant of support assembly 10. For furniture members such as chairs and sofas, occupant weights of approximately 400 pounds and greater were previously not accommodated in the design, which could result in damage to the biasing members, structure or cushions used for the assembly. One or more restrictor elements 26 of the present invention establish a maximum deflection of biasing members 22 corresponding to the predetermined load “L” which permits the support assembly 10 to accommodate predetermined loads “L” of 400 or more pounds.

Referring next to FIG. 4, a depth “C” of frame 12 is identified. In one preferred embodiment of the present invention, biasing members 22 are initially positioned in the non-loaded condition in a position substantially parallel with or arcing above the upper surfaces of frame 12. This allows the deflection of biasing members 22 to be accommodated substantially within the envelope of depth “C”. Restrictor element 26 is either incorporated within depth “C” or alternately can extend below a lower envelope 55 of frame 12.

As best seen in reference to FIGS. 2 and 5, restrictor element 26 includes first and second connecting ends 56, 58. A wire coating 60 is provided over a substantial extent of restrictor element 26. Wire coating 60 is not provided, or if provided, is removed from first and second connecting ends 56, 58. First and second connecting ends 56, 58 are slidably received within apertures 52 provided in first and second contact plates 48, 50. Each of first and second connecting ends 56, 58 form an angle α of approximately 90° to adjacent bend sections. Each of the bend sections adjacent first and second connecting ends 56, 58 form an angle β of approximately 135° from the remaining substantially straight section of restrictor element 26. A total length “D” of restrictor element 26 and a length between bends “E” result after initial bending of restrictor element 26. A bent section length “G” of approximately 1.9 cm (0.75 inches) and a connection length “F” of approximately 2.5 cm (1.0 inches) are provided in one preferred embodiment of the present invention. The above dimensions are exemplary of only one embodiment of the present invention for a restrictor element 26. It will be obvious to a skilled practitioner that multiple designs for restrictor element 26 are possible having a plurality of different dimensions determined by the envelope of support assembly 10.

Referring now to FIG. 6, according to one embodiment, an arc-shaped restrictor element 26 is used. As shown, restrictor element 26 represents a finished shape when each of first and second connecting ends 56, 58 are captured within apertures 52 of first and second contact plates 48, 50. An opposed pair of hooked ends 62 each having a contact area 64 where restrictor element 26 contacts first and second contact plates 48, 50 result upon installation of restrictor element 26. A total wire length “H” corresponds to a center-to-center spacing between apertures 52 of first and second contact plates 48, 50 respectively, in their installed position on each of first and second side rails 16, 18 respectively. A connection length “J” results when the restrictor element 26 is formed in its final finished condition. A desired maximum arc depth “K” is predetermined based on the predetermined load “L” applied to support assembly 10, the size and material used for biasing members 22, and a calculated, estimated or measured total deflection of each of biasing members 22 when predetermined load “L” is applied. In one exemplary embodiment of the present invention, total wire length “H” is approximately 59.7 cm (23.5 inches), and maximum arc depth “K” is approximately 7.6 cm (3.0 inches) for a restrictor element 26 constructed of spring steel in approximately 12 gauge size. This restrictor wire configuration is exemplary for one preferred embodiment of the present invention capable of supporting a predetermined load “L” of approximately 500 pounds at a maximum deflected condition for biasing members 22. If the total load on support assembly 10 increases above the predetermined load “L”, further deflection of biasing members 22 is restricted by restrictor element 26. This prevents over-extension of biasing members 22, potential damage to cushion 20 or a motion mechanism (if installed) below the cushion, and accommodates users of greater weight than currently accommodated in known support assemblies.

Referring generally now to FIGS. 7 and 8, alternate embodiments for restrictor wires of the present invention are shown. A restrictor wire 66 provides a straight section 68 positioned between each of an opposed pair of side legs 70, 72. Side legs 70, 72 transition into each of a pair of connecting ends 74, 76, respectively. A restrictor wire 78 includes a raised bend area 80 positioned between each of a pair of lower bend areas 82, 84 respectively. Lower bend areas 82, 84 transition into each of an opposed pair of side legs 86, 88, respectively. An opposed pair of connecting ends 90, 92 distally extend from each of side legs 86, 88, respectively. The configurations for restrictor wires 66 and 78 of FIGS. 7 and 8 are exemplary only. Multiple geometric designs for restrictor wires of the present invention are possible. Use of multiple geometric designs for restrictor wires of the present invention permits the designer to vary the quantity, size, arrangement and spacing of the biasing members for support assemblies 10 of the present invention.

Referring now to FIG. 9, a maximum deflected condition for cushion 20 and for biasing members 22 is shown. In this embodiment, predetermined load “L” is applied generally at a central point of cushion 20 and is distributed by the various biasing members 22. In alternate embodiments (not shown) predetermined load “L” is applied as a diversified load over a portion of the surface area or to an entire surface area of cushion 20. The maximum deflection condition shown is provided when each of the biasing members 22 reach a contact position with restrictor element 26. In an alternate embodiment (not shown), the maximum deflection condition is reached when any one of the biasing members 22 contacts restrictor element 26. Restrictor element 26 is maintained in the exemplary arc-shaped form by engagement of each of the first and second connecting ends 56, 58 with each of first and second contact plates 48, 50 and first and second side rails 16, 18, respectively. Restrictor element 26 restricts further deflection of biasing members 22 beyond the contact position shown in FIG. 9. A predetermined load “L” of at least 400 pounds and preferably 500 or more pounds can therefore be applied to cushion 20. Biasing member 22′ deflects downwardly (as viewed in FIG. 9) the greatest extent of any of the biasing members before contacting restrictor element 26. The remaining biasing members 22, including biasing member 22″ deflect to a lesser degree before contacting restrictor element 26. An arc-shaped restrictor element 26 reduces the total deflection of biasing members 22 positioned closer to the rails of frame 12, which also permits a portion of predetermined load “L” to be transferred to the rails of frame 12.

The invention is not limited to the configurations shown in the various Figures herein. The description of the present invention is directed to seat cushions wherein an occupant weight is applied in a vertically downward direction, however, seat back cushions, sofa back cushions, and other chair or seat components can also be supported and restricted in their movement by restrictor elements 26 of the present invention. The quantity of biasing members 22 is also not limited. The quantity of biasing members 22 can range from one to greater than five. The arrangements shown herein can also be varied such that the restrictor wires are supported from the front and rear rails of the frame 12 and the biasing members are supported from the first and second side rails. It is also noted that the configuration of restrictor wires can be varied from the orthogonal arrangement described herein such that one or more restrictor wires positioned at a non-orthogonal angle to the biasing members 22, a crossing pattern or other geometric patterns can also be used.

Using the weight of a heavier patron to design a spring system can provide little or no seat travel and therefore reduced seat comfort for lighter weight patrons. The restrictor wire of the present invention allows use of a seat suspension that provides favorable seat comfort for lighter patrons (patrons weighing less than the weight predetermined load) while permitting heavier patrons to use the same seat/seat suspension without bottoming out or yielding the seat suspension. By limiting the total travel of the seat suspension by a restrictor wire of the present invention, a heavier patron is also properly positioned for the size proportions of the seat, such as the back/lumbar position of the seat and a foot rest position, etc.

A furniture support system restrictor wire of the present invention provides several advantages. A restrictor wire of the present invention is manufactured using simple bending steps and is therefore less expensive than adding sinuous or coiled springs to increase a load carrying capacity of a furniture item. By predetermining a maximum load or a maximum deflection of the sinuous springs, the restrictor wire can be dimensioned and its wire size appropriately selected to act as a deflection limiter for the sinuous wire springs. By extending a restrictor wire of the present invention below and generally transverse to the axes of the sinuous springs, clearance is provided to allow limited travel of the springs. When the predetermined load is reached the springs contact the restrictor wire and deflection is thereafter restricted. This prevents damage to the springs or the cushion or a motion mechanism below the cushion while accommodating heavy patrons with a lower cost alternative to more complex spring systems. Restrictor wires having bent or hooked ends received in frame members other than the frame members supporting the springs help distribute cushion loading throughout the frame.

While various preferred embodiments have been described, those skilled in the art will recognize modifications or variations which might be made without departing from the inventive concept. The examples illustrate the invention and are not intended to limit it. Therefore, the description and claims should be interpreted liberally with only such limitation as is necessary in view of the pertinent prior art.