Abstract:
A lever connection comprises a lever having a cable end and a spring end and a pivot point therebetween, and a cable having a cable end fitting attached to an end thereof. The cable end fitting comprises a cable clamp and a frame, the cable clamp being adapted for attachment of the end fitting to the cable, the frame comprising first and second side members, a top member, and a bottom member. The top member is adjacent to the cable clamp and the frame defines an orifice between the first and second side members and the top and bottom members, the side members having a distance therebetween. The cable end of the lever comprises a bearing being sized for insertion through the orifice of the end fitting and adapted for engagement with the bottom member of the frame of the end fitting.

Description:
TECHNICAL FIELD OF THE INVENTION 
   The present invention relates to ergonomic support devices for seats, particularly lumbar supports, and, more particularly, to an improved hinge connection for an adjustment cable in a lumbar support. 
   DESCRIPTION OF THE RELATED ART 
   Powered lumbar support devices intended for use in automobile seat backs typically include a panel that has a first end and a second end and is biased in a forward direction for providing an arch in the seat back. A series of adjustment cables, sometimes referred to as “Bowden” cables and driven by motorized gear boxes, control and change the distance between the first end and the second end of the panel. By changing the distance between the first end and the second end, the arch in the panel is changed for adjusting the amount of lumbar support. 
   As described in U.S. Pat. No. 6,631,951, the comfort of these lumbar supports can be enhanced by use of a compliant spring connected to one of the ends of the panel and with the appropriate adjustment cable. The compliant spring includes a contracting spring force that is greater than the extending force generated by the drive mechanism for the cable. When the panel is subjected to enough force to overcome the contracting spring force of the compliant spring, the compliant spring stretches, increasing the distance between the first end and the second end, changing the arch in the panel. The compliance provided to the panel by the resilient spring provides an additional level of comfort to the seat occupant. 
   The compliant spring is often coupled to the adjustment cable by means of a pivoting lever. A fitting on the end of the adjustment cable engages the pivoting lever. The most common fitting type in general use is a “Z-shaped” fitting that must be inserted into a hole within the lever. These fittings require significant manipulation of the fitting and lever for assembly and often result in a connection that is noisy and may produce significant vibration within the support during movement of the adjustment cable and lever. 
   Therefore, it would be advantageous to provide a hinge connection for a lumbar support that may be assembled with ease and produces less noise and vibration during movement of the support. 
   The present invention is directed to overcoming one or more of the problems set forth above. 
   SUMMARY OF THE INVENTION 
   It is in view of the above problems that the present invention was developed. The present invention overcomes many of the disadvantages associated with prior art cable/lever connections for lumbar supports by providing a hinge connection capable of straightforward assembly and decrease vibration during use. 
   In one aspect the invention is a lever connection comprising a lever having a cable end and a spring end and a pivot point therebetween, and a cable having a cable end fitting attached to an end thereof. The cable end fitting comprises a cable clamp and a frame, the cable clamp being adapted for attachment of the end fitting to the cable, the frame comprising first and second side members, a top member, and a bottom member. The top member is adjacent to the cable clamp and the frame defines an orifice between the first and second side members and the top and bottom members, the side members having a distance therebetween. The cable end of the lever comprises a bearing being sized for insertion through the orifice of the end fitting and adapted for engagement with the bottom member of the frame of the end fitting. 
   In another aspect the invention is a lever connection for a lumbar support device, comprising a lever having a cable end and a spring end and a pivot point therebetween, and a cable having a cable end fitting attached to an end thereof. The cable end fitting comprises a cable clamp and a frame, the cable clamp being adapted for attachment of the end fitting to the cable. The frame comprises first and second side members, a top member, and a bottom member, the top member being adjacent to the cable clamp. The frame defines an orifice between the first and second side members and the top and bottom members, the side members having a distance therebetween. The cable end of the lever comprises a bearing being sized for insertion through the orifice of the end fitting and adapted for engagement with the bottom member of the frame of the end fitting. The bearing comprises a curved structure along a side of the lever at the cable end of the lever, the curved structure having a concave interior profile. The bottom member of the frame of the cable end fitting has a cylindrical profile and the bearing has a semicircular opening that matingly engages with the cylindrical profile of the bottom member of the frame of the cable end fitting. The spring end of the lever is operably attached to a spring. The lever is flat and has a thickness, wherein the thickness is smaller than the distance between the side members of the frame of the cable end fitting. 
   In still another aspect the invention is a cable connector and bearing system for a lumbar support device, comprising a cable with an eye-shaped connector attached to an end of the cable, the connector having a proximal end attached to the cable and a distal end, the distal end being linked to the proximal end by a pair of parallel side portions. A central portion of the distal end comprises an approximately cylindrical shape. The system also comprises a bearing to which the eye-shaped connector of the cable attaches, the bearing itself comprising a concave curve having a profile complementary to the cylindrical shape of the distal end of the connector, the bearing being sized to fit into the connector. 
   These aspects are merely illustrative of the innumerable aspects associated with the present invention and should not be deemed as limiting in any manner. These and other aspects, features and advantages of the present invention will become apparent from the following detailed description when taken in conjunction with the referenced drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Reference is now made more particularly to the drawings, which illustrate the best presently known mode of carrying out the invention and wherein similar reference characters indicate the same parts throughout the views. 
       FIG. 1  is a perspective view of a lumbar support incorporating a hinge connection according to an embodiment of the present invention. 
       FIG. 2  is a front view of another lumbar support incorporating a hinge connection according to an embodiment of the present invention. 
       FIG. 3  is a front view of the lumbar support of  FIG. 2 . 
       FIG. 4  is a perspective view, showing a lumbar support incorporating a hinge connection according to one embodiment of the present invention. 
       FIG. 5  is a front view of a lumbar support incorporating a hinge connection according to one embodiment of the present invention. 
       FIG. 6  is a perspective view of a gear box of a type used in the lumbar supports shown in  FIGS. 1-5 . 
       FIG. 7  is a perspective view of a prior art connection for a lumbar support. 
       FIG. 8  is a perspective view of a fitting for a hinge connection according to an embodiment. 
       FIG. 9  is a perspective view of a bearing for a hinge connection according to an embodiment. 
       FIG. 10  is a perspective view of one embodiment of an assembled hinge connection. 
       FIG. 11  is a front view of one embodiment of an assembled hinge connection. 
       FIG. 12  shows a hinge connection as employed in a lumbar support mechanism. 
   

   DETAILED DESCRIPTION 
   In the following detailed description numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. For example, the invention is not limited in scope to the particular type of industry application depicted in the figures. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the present invention. 
   An embodiment of an automotive seat frame  10  is illustrated in  FIG. 1 . The frame  10  includes a seat section  12  and back section  14 . The back section  14  has a ring  32  defining the perimeter of the back section  14 . An embodiment of a powered lumbar support device  22 , which may be mounted to seat frame  10 , has a lumbar frame  40  with a plurality of hooks  41  at one end and a clasp  43  at the other. The lumbar frame  40  is fixedly attached to the ring  32  by the hooks  41  and the clasp  43 . A panel  44  is slidably disposed generally upon the vertical members  39  of the lumbar frame  40 . The panel  44  has a first end  46  and a second end  48  moveable relative to one another for forming an arch in the panel  44 . 
   A first gear box  16 , best shown in  FIG. 6 , is attached to the lumbar frame  40 , as shown in  FIGS. 1-5 . The first gear box  16  has an arching rack  18  and an arching pinion  20 . The arching rack  18  includes a first arching end  24  and a second arching end  26 . Each of the first and the second arching ends  24 ,  26  are adapted to allow the attachment of cables thereto. More specifically, at least one connector  25  is disposed in each of the first and second arching ends  24 ,  26  for receiving an end of a cable. The connector  25  is represented as a slot having a keyhole shape for receiving the end of the cable. However, the connector  25  is not limited to a slot and may include any means of fixing the cable to the rack as is known in the art. In the preferred embodiment, there are two connectors disposed in each of the arching ends  24 ,  26  and the connector is an aperture for receiving the end of the cable. 
   A first cable  28  is connected between the arching rack  18  and one of the ends  46 ,  48  of the panel  44 . The arching rack  18  moves in a linear direction transferring motion through the first cable  28  causing the end of panel  44  to move. Movement of the two ends  46 ,  48  of panel  44  towards each other changes the magnitude of the arch, thereby providing additional lumbar support to the seat occupant. A first motor  30  operatively engages the first gear box  16  with a worm  34  to transfer linear movement to the arching rack  18  ( FIG. 6 ). The worm  34  is in driving engagement with arching pinion  20 , enabling arching pinion  20  to impart linear movement to arching rack  18 . The first motor  30  is shown generally in  FIGS. 5 and 6  as receiving cables in both ends of the rack, the purpose of which will be described below. A memory device  76  is disposed within the first gear box enabling a predetermined position of the arching rack  18  corresponding to a predetermined magnitude in the arch of the panel  44  to be stored in a controller (not shown). The memory device  76  may be any known device capable of determining the location of the rack  18  and enabling the position of the rack  18  to be stored for returning the rack  18  to that same position when desired. For example, one such device is a memory potentiometer. 
   The lumbar support device  22  further includes a compliant spring  36  interposed between one of the ends  46 ,  48  of the panel  44  and the first cable  28 . The compliant spring  36  transfers movement from the first cable  28  to one of the ends  46 ,  48  of the panel  44 . The compliant spring  36  has an expansion force stronger than the linear force generated by the first motor  30 . Therefore, when the first motor  30  is operated, the ends  46 ,  48  of the panel  44  move without stretching the compliant spring  36 . A lever  38  operably connects the first cable  28  to the compliant spring  36 . Tension (arrow  29  in  FIG. 12 ) applied to first cable  28  causes pivoting movement of lever  38  (double-headed, curved arrow  71  in  FIG. 12 ). 
   A support member  66  is connected to one of the panel ends  46 ,  48  with a pin  65  inserted through opposing tabs  67  allowing pivotal movement of the member  66  relative to the ends  46 ,  48  ( FIG. 2 ). In one embodiment the lever  38  is pivotally supported on the support member  66  by a pin  69 , allowing pivoting movement of the lever  38  relative to the support member  66 . The lever  38  is moved in response to movement of first cable  28  thereby transferring movement from the cable through the lever  38  to one of the ends  46 ,  48  of the panel  44 . The movement of one of the panel ends  46 ,  48  causes the magnitude of the arch of the panel  44  to increase or decrease. 
   The compliant spring  36  allows the arch to flex when an outside force, such as from a passenger sitting in the seat, is exerted against the arch. The force generated by the first motor  30  is not capable of overcoming the contracting spring force of the compliant spring  36 . However, the combination of forces generated by the spring  36  and the motor  30  provide enough counter force to the compliant spring  36  to overcome the contracting spring force of the compliant spring  36  when a predetermined force is exerted upon the panel  44  by a seat occupant. This provides the panel  44  with a compliant feature that increase the level of comfort to the seat occupant by softening the lumbar support provided by the panel  44 . 
     FIG. 7  illustrates a prior art apparatus for this connection. In the prior art, a “Z-shaped” fitting  102  is attached to the free end of first cable  28  by known means such as crimping, welding, or other suitable methods. Prior art fitting  102  is generally cylindrical in its cross-sectional shape with a constant diameter. The fitting  102  includes a top section  104 , a transitional section  106 , and a bottom section  108 . The transitional section  106  includes two opposing bends of approximately ninety degrees (90°) separated by a middle portion. The middle portion is oriented approximately perpendicular to the top  104  and bottom  108  sections of the fitting  102  and the first cable  28 . One end of lever  110  is provided with a hole  112 . Hole  112  has an inside diameter somewhat larger than the outside diameter of fitting  102 . To connect first cable  28  with lever  110 , bottom section  108  is first inserted through hole  112 . Fitting  102  must then be manipulated to guide the ninety degree bend adjacent the bottom section  108  through hole  112 . The middle portion of transitional section  106  is then positioned within hole  112  such that the two ninety degree bends of the transitional section  106  are positioned on either side of lever  110 , loosely securing fitting  102  in engagement with lever  110 . This procedure of guiding Z-shaped fitting  102  into hole  112  is time-consuming and thus costly. The device of the present application simplifies this step of the assembly process, as described below. 
   As shown in  FIGS. 10 and 11 , a lever  38  operably connects the first cable  28  to the compliant spring  36  by means of a hinge connection  78  formed from a fitting  80  ( FIG. 8 ) and bearing  94  ( FIG. 9 ). This rotatable connection is generally accomplished by means of an end fitting attached to the free end of first cable  28  that is adapted to securably engage one end of lever  38 . 
   According to the preferred embodiment, fitting  80  is attached to the free end of first cable  28  ( FIGS. 11 and 12 ). Fitting  80  is generally in the shape of an “eye”, that is, it is provided with a top section  82  and an elongated, O-shaped section  84  ( FIG. 8 ). The top section  82 , or cable clamp portion, of fitting  80  is preferably provided with a central opening along its axis into which the free end of first cable  28  is inserted. Fitting  80  may be secured to the free end of cable  28  by crimping, welding, or any other suitable method, or it may be molded directly onto the cable. Those of skill in the art will recognize that a multitude of suitable attachment methods are known in the art and that the particular method of attaching fitting  80  to first cable  28  is not critical to the invention, provided that the connection is sufficiently strong for the intended purpose. The elongated, O-shaped section  84 , or frame portion of the cable end fitting, includes first and second parallel sides  86 ,  88 , a bottom  90  (or distal portion), and a top  92  (or proximal portion). In the preferred embodiment, the bottom  90  of the elongated, O-shaped section  84  has a cylindrical cross-section and is provided with a rounded interior surface, while the interior surfaces of first and second parallel sides  86 ,  88  are generally flat. Fitting  80  is preferably manufactured as a single, cast or molded piece, and may be made from any suitable, rigid material. Bearing  94  may be part of any component to which fitting  80  needs to be attached, although bearing  94  is preferably part of lever  38 . Bearing  94  may be made of any suitable, rigid material such as metal and its shape may be introduced into the material through known, conventional means such as molding, stamping, cutting, grinding, or the like. 
   The distance between the parallel sides  86 ,  88  of fitting  80  is preferably slightly larger than the thickness of lever  38  to permit ready insertion of the lever  38  through the O-shaped section  84  and smooth movement of lever  38  relative to fitting  80 , while minimizing lateral movement of fitting  80  relative to lever  38  after assembly. 
   In the preferred embodiment, lever  38  is provided with a mating end having a roughly J-shaped, or hook-shaped, bearing  94  for engagement with fitting  80 . Bearing  94  is adapted for insertion through the center of elongated, O-shaped section  84  and engagement with the bottom  90  of fitting  80 . The interior of the bearing  94  preferably forms a roughly semi-circular surface having a radius generally equivalent and complementary to the radius of the bottom  90  of fitting  80 , thereby providing for a solid engagement between the two pieces which allows for smooth rotational movement between the two pieces. The open side of the bearing  94  is advantageously of sufficient size to accommodate the full diameter of the bottom  90  of fitting  80  to allow it access to the interior of bearing  94 . More generally, bearing  94  comprises an upwardly sloped surface leading to a curved end, at one end of lever  38 , of which the disclosed embodiment is but one example. 
   As is readily apparent, the design of the fitting  80  and bearing  94  significantly enhances the ease of assembling lumbar support  10 . While the prior art fitting and lever combination requires significant manipulation of the constituent parts to assemble, the bearing of the present invention may be simply inserted through the fitting and lowered into engagement with the bottom of the fitting to secure the two pieces together. Significantly, the design of the present invention also reduces thrust face contact and increases reaction moments of the fitting compared to the prior art, thereby reducing the amplitude of vibration in the fitting as it rotates in the bearing. This is particularly important as the interaction between fitting  80  and bearing  94  is under tension and subject to continuous movement while the seat occupant is resting against lumbar support  10 . In the absence of a smooth interaction between fitting  80  and bearing  94 , the seat occupant may feel vibrations and hear noise arising from the movement of the cable end relative to the lever. 
   The lumbar support device  22  may also include a second gear box  50  having a moving rack  52  and a moving pinion  54  attached to the lumbar frame  40 , as shown in  FIGS. 2 and 4 . The moving rack  52  has a first moving end  56  and a second moving end  58  with each of the moving ends having at least one connector disposed therein. A second motor  60  having a worm  34  extending from the second motor  60  directly engages the second gear box  50 . The second motor  60  and the second gear box  50  operate in the same manner as the first motor  30  and the first gear box  16 . A second cable  64  is connected between one of the connectors of the moving rack  52  and the support member  66 . The second cable  64  transfers linear movement of the moving rack  52  to the panel  44  for vertically shifting the panel  44 . This moves the lumbar support  22  in the seat back in a generally vertical direction to accommodate various height and comfort preferences of the seat occupant. 
   At least one shifting spring  68  is attached between one of the ends  46 ,  48  of the panel  44  and the lumbar frame  40 , shown in  FIGS. 1 and 2 . When the panel  44  is shifted in a vertical direction by the second cable  64 , the contraction force of the shifting spring  68  is overcome, thereby stretching the shifting spring  68 . When the second motor  60  is not actually shifting the panel  44 , the shifting spring  68  contracts, returning the panel  44  to the original position. In the preferred embodiment, two springs are attached to the frame  10  and the panel  44 , as shown in  FIGS. 1 and 2 . However, it would be readily apparent to one skilled in the art that one spring  32  having a larger force could be used in place of the two springs. 
   In a third embodiment of the powered lumbar support device  22 , shown in  FIGS. 4 and 5 , the shifting spring  68  may be replaced by a third cable  70 . The third cable  70  is connected to the opposite end of the moving rack  52  from the second cable  64  ( FIG. 4 ). Therefore, if the second cable  64  is connected to the first moving end  56  of the moving rack  52  and the third cable  70  is connected to the second moving end  58 , the second and third cable  64 ,  70  shift the panel  44  vertically. When the rack  52  moves downward, the second cable  64  shifts the panel  44  upward. When the rack  52  moves upward, the third cable  70  shifts the panel  44  downward. 
   The preferred embodiment of the invention has been described above to explain the principles of the invention and its practical application to thereby enable others skilled in the art to utilize the invention in the best mode known to the inventors. However, as various modifications could be made in the constructions and methods herein described and illustrated without departing from the scope of the invention, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. Thus, the breadth and scope of the present invention should not be limited by the above-described exemplary embodiment, but should be defined only in accordance with the following claims appended hereto and their equivalents.