Abstract:
The present invention relates to a furniture support structure, and more particularly to a base for supporting a rocking chair. The rocker base has a lower frame, an upper frame, and a plurality of cams. The lower frame has a plurality of lower U-shaped cross members connected to a plurality of side rails, and a plurality of lower spring mounts extending between the lower cross members and connected to the side rails. The upper frame has a plurality of upper U-shaped cross members connected to a plurality of L-shaped side brackets, and a plurality of upper spring mounts extending between the upper cross members and connected to the L-shaped side brackets. The plurality of cams have an arcuate lower surface positioned against the side rails and a flat upper surface attached to the L-shaped side brackets. The cams are compressibly loaded between the side rails and the L-shaped side brackets. The upper spring mounts are inwardly offset from a vertical portion of the L-shaped side brackets to avoid all fasteners joining the cams to the L-shaped side brackets.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   None. 
   FIELD OF THE INVENTION 
   The present invention relates to a furniture support structure, and more particularly to a base for supporting a rocking chair. 
   SUMMARY OF THE INVENTION 
   The present invention is directed to a rocker base for a rocker-recliner chair. In one embodiment, the rocker base has a lower frame, an upper frame, and a plurality of cams. The lower frame has a plurality of lower U-shaped cross members connected to a plurality of side rails, and a plurality of lower spring mounts extending between the lower cross members and connected to the side rails. The upper frame has a plurality of upper U-shaped cross members connected to a plurality of L-shaped side brackets, and a plurality of upper spring mounts extending between the upper cross members and connected to the L-shaped side brackets. The plurality of cams have an arcuate lower surface positioned against the side rails and a flat upper surface attached to the L-shaped side brackets. The cams are compressibly loaded between the lower frame and the upper frame. The upper spring mounts are inwardly offset from a vertical portion of the L-shaped side brackets to avoid all fasteners joining the cams to the L-shaped side brackets. 
   A better understanding of the objects, advantages, features, properties and relationships of the invention will be obtained from the following detailed description and accompanying drawings which set forth illustrative embodiments that are indicative of the various ways in which the principles of the invention may be employed. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention is described in more detail by reference to the drawings, in which: 
       FIG. 1  illustrates a top perspective view of one embodiment of the present invention; 
       FIG. 2  illustrates a bottom perspective view of the embodiment shown in  FIG. 1 ; 
       FIG. 3  illustrates a bottom plan view of the embodiment shown in  FIG. 1 ; 
       FIG. 4  illustrates a top plan view of the embodiment shown in  FIG. 1 ; 
       FIG. 5  illustrates a front elevation view of the embodiment shown in  FIG. 1 ; 
       FIG. 6  illustrates a left side elevation view of the embodiment shown in  FIG. 1 ; 
       FIG. 7  illustrates a rear elevation view of the embodiment shown in  FIG. 1 ; 
       FIG. 8  illustrates a right side elevation view of the embodiment shown in  FIG. 1 ; 
       FIG. 9  illustrates a top perspective detail view of the embodiment shown in  FIG. 1 ; 
       FIG. 10  illustrates a top detail view of the embodiment shown in  FIG. 1 ; 
       FIG. 11  illustrates a bottom perspective detail view of the embodiment shown in  FIG. 1 ; and, 
       FIG. 12  illustrates another bottom perspective detail view of the embodiment shown in  FIG. 1 . 
   

   DETAILED DESCRIPTION 
   The following detailed description illustrates the invention by way of example, not by way of limitation of the scope, equivalents or principles of the invention. This description will clearly enable one skilled in the art to make and use the invention, and describes several embodiments, adaptations, variations, alternatives and uses of the invention, including what is presently believed to be the best modes of carrying out the invention. 
   In this regard, the invention is illustrated in the several figures, and is of sufficient complexity that the many parts, interrelationships, and sub-combinations thereof simply cannot be fully illustrated in a single patent-type drawing. For clarity and conciseness, several of the drawings show in schematic, or omit, parts that are not essential in that drawing to a description of a particular feature, aspect or principle of the invention being disclosed. Thus, the best mode embodiment of one feature may be shown in one drawing, and the best mode of another feature will be called out in another drawing. All publications, patents and applications cited in this specification are herein incorporated by reference as if each individual publication, patent or application had been expressly stated to be incorporated by reference. 
   Turning now to the figures, wherein like reference numerals refer to like elements, there is illustrated in  FIGS. 1-12  rocker base  10  embodying the improvements of the present invention. 
   Referring to  FIGS. 1-2 , rocker base  10  may include upper frame assembly  20 , lower frame assembly  60 , and a plurality of springs  50  positioned therebetween for supporting and operating a conventional rocker/recliner chair. 
   As shown in  FIG. 1 , upper frame assembly  20  may include a plurality of upper U-shaped cross members  24  extending laterally between, and be connected to, a plurality of L-shaped side brackets  110 . Upper frame assembly  20  may also include a plurality of upper spring mounts  30 , each extending between respective pairs of upper U-shaped cross members  24  and connected to an L-shaped side bracket  110 . Upper U-shaped cross members  24  may be welded to L-shaped side brackets  110 . Although welding is known to reduce weight of a finished article as compared to other known fastening methods, it should be understood, however, that other fastening methods known to one of ordinary skill in the art may be employed to secure upper U-shaped cross members  24  to L-shaped side brackets  110 . 
   Upper U-shaped cross members  24  may be oriented such that the open portion  26  of the “U” may be oriented upward toward the chair. However, open portion  26  may be oriented in any direction, such as, upward, forward, rearward, or downward. In addition, open portion  26  of each upper U-shaped cross member  24  may be oriented in different directions from one another. 
   Upper U-shaped cross members  24  and L-shaped side brackets  110  may be made from a heavy gauge steel, or any other material that provides suitable strength, rigidity and life for its intended purpose. To minimize manufacturing and material costs, upper U-shaped cross members  24  may be formed as extrusions using an extrusion process. Alternatively, upper U-shaped cross members  24  may be formed as stampings using a stamping process or as roll-formings using a roll-forming process. In addition, to further minimize material costs and to minimize weight (which may affect shipping costs of rocker base  10 ) without sacrificing strength, upper U-shaped cross members  24  may be configured in a U-shaped cross-section from end to end rather than as a tubular or polygonal cross section. 
   Upper spring mounts  30  may each include at least inside wall  32 , outside wall  34 , and anchor panel  40 . Outside wall  34  may be connected to an L-shaped side bracket  110 , and anchor panel  40  may be connected to respective forward and after upper U-shaped cross members  24 . To add rigidity and torsional stability to upper frame assembly  20  while promoting manufacturing ease, as shown in the figures, the plurality of upper spring mounts  30  may each comprise a shallow, four-sided tray made of heavy gauge steel comprising inside wall  32 , outside wall  34 , forward wall  36 , rear wall  38 , and anchor panel  40 . Forward wall  36  and rear wall  38  may be connected to respective forward and aft upper U-shaped cross members  24 . 
   Upper spring mounts  30  may be formed by bending plate steel along four edges to create the rectangular plan form shown in the figures. Alternatively, upper spring mounts  30  may be formed by welding inside wall  32 , outside wall  34 , forward wall  36 , and rear wall  38  to anchor panel  40  to form the shallow tray described above. 
   Upper spring mounts  30  may be welded to upper U-shaped cross members  24  along forward wall  36  and rear wall  38  of upper spring mounts  30 . In addition, upper spring mounts  30  may be welded to and along an inside edge of L-shaped side brackets  110  by inwardly offsetting upper spring mounts  30  away from the vertical portion of L-shaped side brackets  110 . Although welding is known to reduce weight of a finished article as compared to other known fastening methods, it should be understood, however, that other fastening methods known to one of ordinary skill in the art may be employed to secure upper spring mounts  30  to upper U-shaped cross members  24  and/or L-shaped side brackets  110 . 
   As shown in  FIGS. 9 and 11 , upper spring mounts  30  may include a one or more apertures  42  formed in inside wall  32  for receiving and mounting one or more springs  50 . Upper spring mounts  30  may also include a plurality of spring anchors  44  and spring nubs  46  formed in anchor panel  40 , as best shown in  FIG. 9 , for securing springs  50  to upper spring mounts  30 . Spring anchors  44  may be formed by slicing anchor panel  40  in the shape of an elongated “U” in bending and forming the tab that results around one or more coils of springs  50 . Spring nubs  46  may provide secondary securement of springs  50  to upper spring mounts  30  in addition to spring anchors  44 . 
   To enable a rocker/recliner chair to rock back and forth when mounted to rocker base  10 , upper frame assembly  20  may include a plurality of cams  100 , as best shown in  FIGS. 6  and  8 . Each cam  100  may have an arcuate lower surface positioned against respective side rails  68  of lower frame assembly  60 , and a flat upper surface attached to a bottom surface of L-shaped side bracket  110 . Cams  100  may be manufactured from any suitably stiff material such as wood, plastic, aluminum, or steel, for example. As shown in  FIG. 4 , cams  100  may be secured to L-shaped side brackets  110  using a plurality of fasteners  102 . It should be understood, however, that other fastening methods known to one of ordinary skill in the art may be employed to secure cams  100  to L-shaped side brackets  110 . 
   Referring again to  FIG. 2 , lower frame assembly  60  may comprise a plurality of lower U-shaped cross members  64  extending laterally between, and connected to, a plurality of side rails  68 . Lower frame assembly  60  may also include a plurality of lower spring mounts  80  extending between respective pairs of lower U-shaped cross members  64  and connected to respective side rails  68 . Side rails  68  may be positioned transverse to upper and lower U-shaped cross members  24 ,  64 . Lower U-shaped cross members  64  may be welded to side rails  68 . Although welding is known to reduce weight of a finished article as compared to other known fastening methods, it should be understood, however, that other fastening methods known to one of ordinary skill in the art may be employed to secure lower U-shaped cross members  64  to side rails  68 . 
   Lower U-shaped cross members  64  may be oriented such that the open portion  66  of the “U” may be oriented downward toward the floor. However, open portion  66  may be oriented in any direction, such as, upward, forward, rearward, or downward. In addition, open portion  66  of each lower U-shaped cross member  64  may be oriented in different directions from one another. Lower U-shaped cross members  64  may be made from a heavy gauge steel, or any other material that provides suitable strength, rigidity and life for its intended purpose. 
   Lower U-shaped cross members  64  and side rails  68  may be made from a heavy gauge steel, or any other material that provides suitable strength, rigidity and life for its intended purpose. To minimize manufacturing and material costs, lower U-shaped cross members  64  and side rails  68  may be formed as extrusions using an extrusion process. Alternatively, side rails  68  may be formed as seamless tubes or as welded tubes. 
   In addition, to further minimize material costs and to minimize weight (which may affect shipping costs of rocker base  10 ) without sacrificing strength, lower U-shaped cross members  64  may be configured in a U-shaped cross-section from end to end rather than as a tubular or polygonal cross section. As shown in the figures, side rails  68  may be configured to have a generally square cross section, however, side rails  68  may be configured to have other open or closed cross-sectional shapes, such as U-shaped, tubular, rectangular, etc. 
   Lower spring mounts  80  may each include at least inside wall  82 , outside wall  84 , and anchor panel  90 . Outside wall  84  may be connected to a side rail  68 , and anchor panel  90  may be connected to respective forward and after lower U-shaped cross members  64 . To add rigidity and torsional stability to lower frame assembly  60  while promoting manufacturing ease, as shown in the figures, the plurality of lower spring mounts  80  may each comprise a shallow, four-sided tray made of heavy gauge steel comprising inside wall  82 , outside wall  84 , forward wall  86 , rear wall  88 , and anchor panel  90 . Forward wall  86  and rear wall  88  may be connected to respective forward and aft lower U-shaped cross members  64 . 
   Lower spring mounts  80  may be formed by bending plate steel along four edges to create the rectangular plan form shown in the figures. Alternatively, lower spring mounts  80  may be formed by welding inside wall  82 , outside wall  84 , forward wall  86 , and rear wall  88  to anchor panel  90  to form the shallow tray described above. 
   Lower spring mounts  80  may be welded to lower U-shaped cross members  64  along forward wall  86  and rear wall  88  of lower spring mounts  80 . In addition, lower spring mounts  80  may be welded to side rails  68 . Although welding is known to reduce weight of a finished article as compared to other known fastening methods, it should be understood, however, that other fastening methods known to one of ordinary skill in the art may be employed to secure lower spring mounts  80  to lower U-shaped cross members  64  and/or side rails  68 . 
   As shown in  FIGS. 11-12 , lower spring mounts  80  may include one or more apertures  92  formed in inside wall  82  for receiving and mounting one or more springs  50 . Lower spring mounts  80  may also include a plurality of spring anchors  94  and spring nubs  96  formed in anchor panel  90 , as best shown in  FIG. 12 , for securing springs  50  to lower spring mounts  80 . Spring anchors  94  may be formed by slicing anchor panel  90  in the shape of an elongated “U” in bending and forming the tab that results around one or more coils of springs  50 . Spring nubs  96  may provide secondary securement of springs  50  to lower spring mounts  80  in addition to spring anchors  94 . 
   Referring to  FIGS. 1-4 , side rails  68  of lower frame assembly  60  may include shoes  70  positioned over each end of side rails  68  to provide a non-marring contact surface where rocker base  10  meets a floor or supporting surface. To create feet for supporting rocker base  10  and to accommodate shoes  70 , each end of side rails  68  may be bent and/or flattened using, for example, a hydraulic press, to form the “S” profile shown in  FIGS. 6 and 8 . 
   Shoes  70  may comprise any one of a number of materials that have non-marring qualities, such as rubber or rubberized materials, elastomerics, and the like. In addition, shoes  70  may be configured, using materials, geometry, or both, to have sufficient friction between rocker base  10  and the floor or supporting surface to prevent slippage and unwanted or unintended movement of rocker base  10  relative to the floor or supporting surface during operation of a rocker/recliner chair mounted to rocker base  10 . 
   Shoes  70  may be secured to each end of each side rail  68  using, for example, frictional forces between mating internal and external surfaces of shoes  70  and side rails  68 , respectively. In addition or alternatively, shoes  70  may be secured to side rails  68  using adhesives, fasteners, or by a positive retention mechanism. One such positive retention mechanism is shown in  FIGS. 1 and 4 . For example, respective ends of side rails  68  may include ramps or wedges  76  for receiving receptacles  71  on shoes  70 . To install and positively retain shoes  70  onto side rails  68 , shoes  70  may be pushed onto, and elastically deformed over, respective ends of side rails  68  until ramps or wedges  76  of shoes  70  engages receptacles  71 . 
   When viewed from the top, as shown in  FIG. 4 , upper frame assembly  20  may be positioned atop lower frame assembly  60  such that respective fore and aft upper U-shaped cross members  24  may be positioned directly above respective fore and aft lower U-shaped cross members  64 . Similarly, respective upper spring mounts  30  may be positioned directly above respective lower spring mounts  80 . As shown in the figures, the size and geometry of upper spring mounts  30  may be approximately equal to the size and geometry of lower spring mounts  80 . However, though upper U-shaped cross members  24  may have the same geometry as lower U-shaped cross members  64 , upper U-shaped cross members  24  are necessarily longer than lower U-shaped cross members  64  due to the geometry and position of L-shaped side brackets  110 . 
   As shown in  FIGS. 5-8 , cams  100  may be compressibly loaded between side rails  68  of lower frame assembly  60  and L-shaped brackets  110  of upper frame assembly  20  by tensioning springs  50 . In this way, springs  50  may cause a return force to be exerted on upper frame assembly  20  whenever upper frame assembly  20  is rocked fore and aft of the neutral position shown in each of  FIGS. 1-12 . In addition, coils  52  of respective springs  50  that are mounted on respective pairs of upper and lower spring mounts  30 , 80  may be oriented in opposite directions (i.e., clockwise and counter-clockwise) to help insure symmetrical loading of lower frame assembly  60  and upper frame assembly  20 . Thus, for example, a forward spring  50  may be coiled in the counterclockwise direction when viewing rocker base  10  from above, as in  FIG. 4 , while an adjacent, aft spring  50  may be coiled in the clockwise direction. This orientation of coils may be mirrored on the opposite side of rocker base  10 . 
   As shown in  FIGS. 5 and 8 , L-shaped side brackets  110  may be positioned so that the bottom portion of the “L” lays flat against cams  100 . In addition, L-shaped side brackets  110  may be oriented with the vertical portion of the “L” positioned to the outside of each of the left and right sides, respectively, for ease of installation and assembly, and to promote maximum stability, of a rocker/recliner chair to rocker base  10 . Thus, respective ends of upper U-shaped cross members  24  may rest on top of the bottom portion of the “L” of L-shaped side brackets  110  to permit maximum surface area exposed to welding upper U-shaped cross members  24  to L-shaped side brackets  110  thereby resulting in maximum rigidity of this connection. 
   To secure and anchor a rocker/recliner chair to rocker base  10 , L-shaped side brackets  110  and side rails  68  may each contain a plurality of apertures  112  and  78 , respectively, as best shown in  FIG. 1 , for receiving a plurality of fasteners. 
   While specific embodiments of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangement disclosed is meant to be illustrative only and not limiting as to the scope of the invention which is to be given the full breadth of the appended claims and any equivalents thereof.