Abstract:
A rocker base assembly for rocking support of a chair frame comprising a base having a pair of side rails connected by a pair of connecting base rails, a rocker assembly supported thereon and having a pair of rocker cams fixedly connected by a pair of connecting rocker rails and a plurality of rocker spring assemblies adjustably secured between the connecting base rails and connecting rocker rails and supporting the rocker cams for rocking motion on the side rails.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates generally to a rocker base assembly for rocking support of a chair assembly and, more particularly, to a rocker base assembly having slotted openings, which allow for adjustable rocking support of a chair assembly.  
       BACKGROUND OF THE INVENTION  
       [0002]     Rocker chairs conventionally comprise a fixed base with a rocker assembly, generally including rocker cams, resting on the fixed base and supporting the seat and back rest of the chair. Rocking motion of the chair is conventionally controlled by spring assemblies connected between the rocker cams and the base, with the center of gravity of the chair determining an equilibrium resting disposition of the chair when not rocking.  
         [0003]     Generally the connections of the rocker cams, spring assemblies and base are not conveniently adjustable in a forward and backward direction relative to the base to compensate for differences in the center of gravity of the chair due to different chair styles or different body sizes of people occupying the chair. However a rocker base assembly which allows for adjustment of the rocker cams relative to the base and adjustment of the rocker springs via the rocker assembly relative to the base is known from U.S. Pat. No. 6,000,754. In this known rocker base assembly, the rocker springs remain securely fastened to the rocker assembly during adjustment.  
         [0004]     It is an object of the present invention to provide a rocker base assembly wherein the spring assemblies are adjustable preferably in a forward and rearward direction relative to the base independently of the rocker cams and base.  
       SUMMARY OF THE INVENTION  
       [0005]     Briefly summarized, the present invention addresses this objective by providing a rocker base assembly wherein the spring assemblies are adjustable independently of the rocker cams and base. More particularly, the rocker base assembly is adapted to rest stationary on a floor surface for rocking support of a chair frame on the base assembly and comprises a base, a rocker assembly and a plurality of spring assemblies. The base has a pair of side rails rigidly connected in laterally spaced relation to one another by a pair of connecting base rails that are affixed in spaced relation transversely between the side rails. The rocker assembly comprises a pair of rocker cams and a pair of connecting rocker rails affixed in spaced relation transversely to one another between the rocker cams. The plurality of rocker spring assemblies are fixed between the connecting base rails and the connecting rocker rails and support the rocker cams for rocking motion on the side rails. The plurality of rocker spring assemblies yieldably bias the rocker assembly for forward and rearward rocking motion relative to an equilibrium position thereof on the base. Each of the connecting base rails and the connecting rocker rails have a plurality of slotted openings elongated in the direction of rocking motion of the rocker assembly for adjustably receiving fasteners for securing the plurality of spring assemblies in place between the connecting base rails and the connecting rocker rails in selectively differing orientations relative thereto.  
         [0006]     In a preferred embodiment, the pair of side rails are disposed in spaced parallel relation to one another and the connecting base rails are welded perpendicularly between the side rails. The rocker assembly preferably comprises a pair of angle plates fixedly connected respectively to the upper surfaces of the pair of rocker cams and the connecting rocker rails are welded to and extend between the pair of angle plates. The connecting rocker rails are spaced relative to one another a distance corresponding to that of the connecting base rails. It is further preferred that the rocker base assembly comprises a pair of mounting plates fixedly connected respectively to the rocker assembly. The rocker base assembly may optionally comprise a reclining mechanism mounted on the rocker assembly.  
         [0007]     Another aspect of the present invention provides a rocker chair comprising a rocker base assembly in combination with a chair frame. The rocker base assembly is of the basic type above-described, comprising a base with side rails and transverse connecting base rails, a rocker assembly with a pair of rocker cams joined by transverse connecting rocker rails, and plural rocker spring assemblies fixed between the connecting base rails and the connecting rocker rails to support the rocker cams for rocking motion on the side rails. The chair frame comprises a seat and a backrest, affixed to mounting plates connected to the rocker assembly. Each of the connecting base rails and the connecting rocker rails have a plurality of slotted openings elongated in the direction of rocking motion of the rocker assembly for adjustably receiving fasteners for securing the plurality of spring assemblies in place between the connecting base rails and the connecting rocker rails in selectively differing orientations relative thereto.  
         [0008]     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 the preferred embodiment 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  
       [0009]     The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:  
         [0010]      FIG. 1  is a perspective view, partially cut-away, of a rocker chair with the rocker base assembly of the present invention.  
         [0011]      FIG. 2  is a perspective view of the rocker base assembly of the present invention.  
         [0012]      FIG. 3  is a top view of the rocker base assembly of  FIG. 2 .  
         [0013]      FIGS. 4A-4G  are side cross-sectional views of the rocker base assembly of  FIG. 2 . 
     
    
     DESCRIPTION OF EMBODIMENTS  
       [0014]     The following description of embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.  
         [0015]     Referring now to the accompanying drawings, in which like numerals represent like components throughout the several views, and with initial references to  FIG. 1 , a chair is indicated overall at  10  in combination with the rocker base assembly  18  of the present invention. The chair  10  basically includes a seat  12 , arms  14 , and a backrest  16  all supported on the rocker base assembly  18  of the present invention. While the chair  10  shown is an upholstered chair, it will be appreciated that various other forms of upholstered and non-upholstered chairs, e.g. a wood-frame chair, may also be used with the rocker base assembly  18  of the present invention.  
         [0016]      FIGS. 2 and 3  show a larger view of the rocker base assembly  18 . As shown, the rocker base assembly  18  comprises a base  20 , which includes a pair of side rails  22  and a pair of connecting base rails  24 , and a rocker assembly  26 , which includes a pair of rocker cams  28  and a connection assembly  30 . The connection assembly  30  includes a pair of angle plates  32  and a pair of connecting rocker rails  34 . The rocker base assembly  18  also includes a pair of rocker spring assemblies  36  situated between the base  20  and the rocker assembly  26 .  
         [0017]     The base  20  is preferably made of metal and is adapted to rest stationary on a floor surface. The base  20  is formed of the pair of side rails  22  rigidly connected in spaced parallel relation by the pair of connecting base rails  24  welded in spaced relation to one another perpendicularly between the side rails  22 . Feet are mounted on the ends of the side rails  22 , to protect the floor on which the base  20  rests. The pair of rocker cams  28  are respectively supported on the side rails  22  for rocking motion relative to the side rails  22 . The rocker cams  28  are connected to one another for coordinated rocking motion by the connection assembly  30  formed of the angle plates  32  fixed by screws  38  to the upper surfaces of the rocker cams  28  and the connecting rocker rails  34  welded in spaced relation to one another perpendicularly between the angle plates  32 . A pair of mounting plates  40  are fixedly connected to the angle plates  32  for connecting the rocker base assembly  18  to the frame of the chair  10 .  
         [0018]     The connecting rocker rails  34  of the rocker cam connection assembly  30  are spaced relative to one another a distance corresponding to that of the connecting base rails  24  of the base  20 . Two rocker spring assemblies  36  are fixed between the connecting base rails  24  and the connecting rocker rails  34  to urge the entire rocker assembly  26  to an equilibrium position, while being yielding for rocking motion forwardly and rearwardly of the equilibrium position. Each rocker spring assembly  36  comprises two rocker springs  50  fixed adjacent to one another and interposed between a pair of spring connecting plates  48  to which the rocker springs  50  are attached. Each of the spring connecting plates  48  has two attachment holes  52  (shown in FIGS.  4 A-G), one on each end, for mounting the spring assemblies  36  to the connecting rocker rails  34  and connecting base rails  24  respectively. In this manner, the springs  50  of the rocker spring assemblies  36  urge the entire rocker assembly  26  to an quilibrium position when at rest with no rocking force exerted on the chair frame, but the springs  50  are yieldable to permit rocking motion of the entire rocker assembly  26  on the base  20  forwardly and rearwardly relative to the equilibrium position.  
         [0019]     The rocker base assembly  18  can be used for a dedicated rocker chair or, alternatively, recliner linkages (shown only schematically at  25  in broken lines in  FIG. 1 ) can be mounted between the mounting plates  40  of the rocker cam connection assembly  30  and the chair frame for use as a rocker-recliner chair. Recliner linkages are well-known in the art and are capable of moving the seat and backrest in an articulated motion between an upright position and a reclined position wherein a footrest associated with the recliner linkage is extended.  
         [0020]     The rocker base assembly  18  does not provide any adjustability in the mounting of the rocker connection assembly  30  to the rocker cams  28 . Specifically, the angle plates  32  have only one set of holes  42  for affixation by screws  38  to the rocker cams  28  in a single position. Likewise, there is no adjustability in the mounted location of the mounting plates  40  of the rocker connection assembly  30 ; i.e., only one mounting location  44  is provided for affixation of each mounting plate  40  to its respective angle plate  32 . On the other hand, in accordance with the present invention, the rocker base assembly  18  does provide a unique form of adjustability in the mounting of the rocker spring assemblies  36  between the base  20  and the rocker assembly  26  via adjustable mounting of the spring assemblies  36  to the connecting base rails  24  and the connecting rocker rails  34 . Specifically each set of connecting rails  24 ,  34  is provided with elongated slotted openings  46  for receiving fasteners  54  for securing the spring assemblies  36  in place via their spring connecting plates  48  between the respective sets of connecting rails  24 ,  34 . The embodiment illustrated herein shows the fasteners as screws, however fasteners may also include mounting bolts or equivalents thereof. The slotted openings  46  are oriented in the direction of rocking motion of the rocker assembly  26  and permit selective forward-rearward positioning of the spring assemblies  36  relative to the two sets of connecting rails  24 ,  34 . This arrangement permits adjustability in the spring biasing characteristics of the spring assemblies  36 , which is of benefit in setting up the base  20  relative to the particular chair structure  10  which will be mounted thereon, e.g. to compensate for variations in the centers of gravity of chairs having differing frame structures, differing upholstery, etc.  
         [0021]      FIGS. 4A-4G  illustrate various forward-rearward adjustment options that are available with the slotted openings  46  of the two sets of connecting rails  24 ,  34 . In  FIG. 4A , the spring assemblies  36  are shown as positioned such that the screws  54  securing the spring assemblies  36  to the connecting rails  24 ,  34  are positioned in the center of each of the elongated openings  46  of each of the connecting rails  24 ,  34 . Thus in the arrangement of  FIG. 4A , the connecting rocker rails  34  of the rocker assembly  26  are directly aligned over the connecting base rails  24  of the base  20 .  
         [0022]     In  FIG. 4B , the spring assemblies  36  remain in the same disposition relative to the connecting base rails  24  as in  FIG. 4A , with the securing screws  54  disposed centered along the slots  46  in the connecting base rails  24 . However, in contrast to  FIG. 4A , the connecting rocker rails  34 , and hence the rocker assembly  26 , has been moved in a rearward direction relative to the base  20  to the fullest available extent so that the screws  54  that secure the springs assemblies  36  to the connecting rocker rails  34  are abutting against the forward ends of the elongated openings  46  of the connecting rocker rails  34 . Thus, in the arrangement of  FIG. 4B , the connecting rocker rails  34  of the rocker assembly  26  are disposed at a slightly rearward offset relative to the connecting base rails  24  of the base  20 .  
         [0023]     In  FIG. 4C , rocker assembly  26  and the spring assemblies  36  have been moved from the disposition of  FIG. 4B  in a forward direction relative to the base  20  to the fullest available extent such that the screws  54  that secure the spring assemblies  36  to the connecting base rails  24  are abutting against the forward ends of the elongated openings  46  of the connecting base rails  24 . The disposition of the rocker assembly  26  relative to the spring assemblies  36  remains the same as in  FIG. 4B , disposed to the fullest rearward extent relative to the spring assembly  36 . In  FIG. 4C , the connecting rocker rails  34  and connecting base rails  24  are again vertically aligned, as they were in  FIG. 4A , however in  FIG. 4C , the spring assemblies  36  are positioned in a more forward direction relative to the base  20  than in  FIG. 4A   
         [0024]     In  FIG. 4D , the rocker assembly  26  remains in the same disposition relative to the spring assemblies  36  as in  FIGS. 4B and 4C , disposed to the fullest rearward extent of the rocker assembly  26  on the spring assemblies  36 . However, in contrast to the arrangement of  FIG. 4C , the rocker assembly  26  and spring assemblies  36  have been moved in a rearward direction relative to the base  20  to the fullest available extent bringing the screws  54  connecting the spring assemblies  36  to the connecting base rails  24  into abutment against the rear ends of the elongated openings  46  of the connecting base rails  24 . Thus,  FIG. 4D  depicts the most rearward disposition of the spring assemblies  36  and, thereby, the most rearwardly biased configuration available for this embodiment of the rocker base assembly  18 .  
         [0025]     In  FIG. 4E , the rocker assembly  26  and the spring assemblies  36  remain in the same disposition relative to the base  20  as in  FIG. 4D , but the rocker assembly  26  has been moved in a forward direction relative to the spring assemblies  36  and the base  20  so that the screws  54  securing the connecting rocker rails  34  to the spring assemblies  36  are abutting against the rear ends of the elongated openings  46  of the connecting rocker rails  34 . Thus, in  FIG. 4E , the connecting rails  24 ,  34  are again aligned vertically, as in  FIGS. 4A and 4C ; however, the spring assemblies  36  are positioned in a more rearward direction relative to the base  20  than in  FIG. 4A .  
         [0026]     In  FIG. 4F , the rocker assembly  26  remains in the same forward disposition relative to the spring assemblies  36  a in  FIG. 4E , but in contrast to  FIG. 4E , the rocker assembly  30  and the spring assemblies  36  have been moved as a unit in a forward direction relative to the base  20  so the screws  54  securing the spring assemblies  36  to the connecting base rails  24  are located at the center along the elongated openings  46  of the connecting base rails  24 . Thus, in this arrangement, the connecting rocker rails  34  are disposed at a slightly forward offset relative to the connecting base rails  24 .  
         [0027]     In  FIG. 4G , the rocker assembly  26  remains in the same forward disposition relative to the spring assemblies  36  as in  FIG. 4E , but in contrast to  FIG. 4E , the rocker assembly  30  and the spring assemblies  36  have been moved as a unit in a forward direction relative to the base  20  to the fullest available extent such that the screws  54  securing the spring assemblies  36  to the connecting base rails  24  are abutted against the forward ends of the elongated openings  46  of the connecting base rails  24 . Thus,  FIG. 4G  depicts the most forward disposition of the spring assemblies  36  and, in turn, the most forwardly biased configuration available for this embodiment of the rocker base assembly  18 .  
         [0028]     Advantageously, the present invention provides a unique and simplified form of adjustability of the relationships between the rocker spring assemblies, the base  20  and rocker assembly  26 . The present invention in comparison to conventional rocker base assemblies, wherein no adjustability of rocker springs assemblies is available, provides more flexibility and is less costly for chair manufacturers because they can use a single rocker base assembly for various chairs rather than needing a different rocker base assembly for different chair sizes and styles. The present invention in comparison to a known adjustable rocker base assembly is more simple and is relatively easy to manufacture. There is no need for machining multiple holes to allow for adjustability. Rather, adjustability is enabled by having elongated openings in the connecting base rails and connecting rocker rails. Manufacturing is simplified because the same connecting rails may be used for both the connecting base and connecting rocker rails.  
         [0029]     It will therefore be readily understood by those persons skilled in the art that the present invention is susceptible of broad utility and application. Many embodiments and adaptations of the present invention other than those herein described, as well as many variations, modifications and equivalent arrangements, will be apparent from or reasonably suggested by the present invention and the foregoing description thereof, without departing from the substance or scope of the present invention. Accordingly, while the present invention has been described herein in detail in relation to its preferred embodiment, it is to be understood that this disclosure is only illustrative and exemplary of the present invention and is made merely for purposes of providing a full and enabling disclosure of the invention. The foregoing disclosure is not intended or to be construed to limit the present invention or otherwise to exclude any such other embodiments, adaptations, variations, modifications and equivalent arrangements.