Abstract:
A furniture construction and a method of placing a section of fabric in tension on the furniture construction includes providing a pair of rigid members each having a slot extending along one side. A rigid edge portion is provided on opposite sides of the section of fabric. Each rigid edge portion is then inserted into the slot of each rigid member such that the fabric overlies an adjacent side surface of each rigid member. The rigid members are then moved in opposing directions thereby place the fabric in tension. The edge portion of the fabric is sufficiently rigid to retain the fabric within the slot and thereby retain the fabric in tension. The rigid members are then secured to the furniture construction.

Description:
BACKGROUND OF THE INVENTION 
   The present invention relates to furniture construction, in particular, it relates to tensioning fabric in furniture construction. 
   Furniture having strips of flexible material or entire sheets of flexible material stretched over a framework are popular. Some methods of stretching flexible sheets of material over chair frames are described in U.S. Pat. Nos. 4,371,142, 4,456,301, 4,592,126, 6,341,822 and 6,345,482. 
   SUMMARY OF THE INVENTION 
   The present invention includes a furniture construction and a method of placing a section of fabric in tension on the furniture construction. The section of fabric is placed in tension between two spaced apart rigid members, each of the rigid members having a slot extending along one side. A sufficiently rigid edge portion is provided on opposite sides of the section of fabric. Each sufficiently rigid edge portion is then inserted into the slot of each rigid member such that the fabric overlies an adjacent side surface of each rigid member. The edge portion of the fabric is sufficiently rigid to retain the fabric within the slot. The rigid members are then moved in opposing directions thereby placing the fabric in tension. The rigid members are then secured to the furniture construction. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is perspective view of the present invention. 
       FIG. 2  is an enlarged perspective view of a portion of the chair construction illustrated in  FIG. 1 . 
       FIG. 3  is a sectional view of rigid member with fabric attached thereto. 
       FIG. 4  is a plan view illustrating a method of placing the fabric section in tension. 
   

   DETAILED DESCRIPTION 
   A chair construction of the present invention is generally indicated at  10  in  FIG. 1 . Like reference characters will be used to indicate like elements in the drawings. Although a chair construction is specifically illustrated, it is understood that the present invention is applicable to other furniture constructions. The present invention also includes a method of placing a section of fabric  12  in tension between two rigid seat members  14  and  16 . As specifically illustrated, the section of fabric  12  and the rigid seat members  14  and  16  form a seat portion  18  of the chair construction  10 . The method of the present invention is also used to form a back portion  34  of the chair construction. Although a single seat chair is illustrated, the method of the present invention may be used for chairs providing for more than single occupancy or which have more than one seat and back portion. 
   The chair construction  10  includes a framework  20  that can be made of plastic, aluminum or steel. The framework includes legs  22 ,  24 ,  26  and  28 . A front crossbrace  25  and a rear crossbrace  27  extend between and connect the legs  26  and  28  and the legs  22  and  24 , respectively. In the embodiment illustrated, the legs  26  and  28  have upper portions  30  and  32  which serve as arms and which are integrally conjoined behind the back portion  34 . The particular construction of the framework  20  is not especially important to the present invention, and is described herein as one exemplary type of framework for which the present invention is suitable. 
   To form the seat portion  18 , the rigid seat members  14  and  16  are provided with a downwardly facing slot  36  as best illustrated in  FIGS. 2 and 3 . The slot  36  runs the length of the rigid members. The section of fabric  12  includes a semi-rigid or rigid edge portion  38  that extends along the length of opposing edge portions. The fabric section  12  overlies the seat member  16  along an outwardly facing side  31  adjacent to the slot  36  and extends over an upwardly facing side  41 , as illustrated in  FIG. 3 . Although only the seat member  16  is specifically illustrated in  FIG. 3 , the seat member  14  is similar as a mirror image in both construction and how the fabric section  12  overlies the seat member  14 . 
   The semi-rigid or rigid edge portion  38  is sufficiently rigid to secure the section of fabric  12  to the seat member  16  by engagement with the slot  36 . Preferably, the edge portion  38  is made of a section of plastic  40  that is attached to an edge portion  42  of the section of fabric  12  by a method that is well known. For example, such rigid edge portions are provided to canvas tops for Jeep Wrangler vehicles made by Chrysler-Daimler to secure the canvas in certain places along the vehicle by engaging selectively positioned slots. It should be understood that other constructions and methods are included within the present invention to make the edge portion  38  sufficiently rigid to secure the fabric to either seat member  14  or  16 . By sufficiently rigid is meant that once the edge portion is positioned within the slot and the fabric is placed along the adjacent side  31 , the edge portion is retained within the slot since the edge portion cannot slide out due to its rigidity. 
   The section of fabric  12  is made of a stretch fabric woven from an all-weather, vinyl-coated, flexible and elastic polyester yarn, such as PHIFERTEX® fabric made by Phifer Wire Products, Inc. of Tuscaloosa, Ala. An example of a stretchable fabric useful in this invention is described in U.S. patent application Ser. No. 10/369,444, entitled Chair Seat With Firm But Resilient Front Edge, filed on Feb. 19, 2003, which is herein incorporated by reference in its entirety. 
   The section of fabric  12  of the seat portion  18  is placed in tension by initially inserting the rigid edge portions  38  into the slots  36  of the rigid seat members  14  and  16 . In one example of the method of construction of the present invention, rigid seat members  14  and  16  each have two sets of apertures  46  and  47  with one set of aperture positioned near the front crossbrace and one set of apertures positioned near the rear crossbrace, as best illustrated in  FIGS. 2 and 4 . 
   The apertures  46  and  47  are engaged by spreader tools  48  and  50 . Referring to  FIG. 4 , the spreader tool  50  is illustrated with respect to the fabric  12 , and in relation to the front crossbrace  25 . Both spreader tools  48  and  50  are essentially the same, and therefore only spreader tool  50  will be described. The spreader tool  50  includes a pneumatic or hydraulic cylinder  52  which provides a force to move the seat members  14  and  16  in the direction of arrows  54 . The spreader tool  50  at each end includes pins  56  and  58  which engage apertures  46  and  47  of the rigid seat members  14  and  16 , respectively. Each pin  56  and  58  engages both the apertures  46  and  47  to prevent the seat members  14  and  16  from rotating about their axis when the section of fabric is placed in tension. Both spreader tools  48  and  50  are used to move the seat members  14  and  16  away from each other to place the section of fabric  12  in tension. 
   To retain the seat members  14  and  16  in position on the frame  20 , the front crossbrace  25  includes retainer tabs  64  and  66 . Similarly, the rear crossbrace  27  includes similar retainer tabs, only one of which is shown ( 68 ). The retainer tabs of the front and rear crossbraces are positioned from each other at a distance which matches a selected distance which seat members  14  and  16  are to be spread apart for the selected tension of the section of fabric  12 . 
   The spreader tools  48  and  50  spread the seat members  14  and  16  sufficiently far enough so that inside faces  60  and  62  of the seat members  14  and  16  extend beyond the retaining tabs  64  and  66 . The retaining tabs are preferably permanently secured to the respective crossbraces such as by welding. 
   Once the seat members  14  and  16  are positioned beyond the retaining tabs of the front and rear crossbraces, the spreader tools  48  and  50  may be drawn in and the pins disengaged from apertures  46  and  47 . Just prior to the disengagement of the spreader tools or directly thereafter, the seat members  14  and  16  are secured to the retaining tabs by screws  70  and  72  which extend through apertures  74  and  75  and into the seat members  14  and  16 . The seat members  14  and  16  are similarly attached to the retaining tabs of the rear crossbrace  27 . The screws  70  and  72  are exemplary of fasteners that may be used to secure the seat members  14  and  16  in position. Other fasteners or other fastening systems such as adhesives or welding are included within the present invention. Detachable fasteners such as screws have the advantage that the section of fabric may be easily replaced by detaching the seat members  14  and  16  from the frame  20 . 
   The back portion  34  is similarly constructed. The back portion  34  is also made of a section of fabric  76  that is in tension between back rigid members  78  and  80 , as best illustrated in  FIG. 1 . The back members  78  and  80  are similar in construction and have the same cross-section as the seat members  14  and  16  illustrated in  FIG. 3 . The section of fabric  76  also includes rigid end portions similar to the edge portions of fabric  12  that are placed within the slots of the back members  78  and  80 . The section of fabric  76  is also placed into tension in a similar manner using spreader tools  48  and  50 . The back members  78  and  80  are spread sufficiently far apart to extend beyond retaining tabs  82  and  80  that extend from the rear crossbrace  27  and retaining tabs  84  and  85  which extend from arm sections  30  and  32  that extend behind the back portion  34  of the chair. The retaining tabs are preferably fixedly attached to the crossbrace and arm sections such as by welding. 
   Once the back members  78  and  80  are moved beyond the retaining tabs  81 ,  84  and  82 ,  85 , the back members  78  and  80  are attached to the retaining tabs, and the spreader tools are disengaged from the back members  78  and  80 . Screws (not illustrated) are used in the same manner as screws  70  and  72  to attach the back members  78  and  80  to the retaining tabs  81 ,  82 ,  84  and  85 . 
   Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.