Patent Publication Number: US-8979186-B2

Title: Power mechanism for recliners

Description:
PRIORITY CLAIM 
     This application claims priority to U.S. Provisional Application No. 61/708,989, filed Oct. 2, 2012, U.S. Provisional Application No. 61/738,737, filed Dec. 18, 2012, and U.S. Provisional Application No. 61/801,967, filed Mar. 15, 2013, each of which is hereby fully incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention is directed to a power mechanism for driving the movable elements of a recliner. Specifically, the present invention is directed to a power mechanism having a limiter controlling the angular collapse of scissoring transfer linkages in the power mechanism to reduce strain on the linkages and spikes in the applied force from the drive assembly for the power mechanism. 
     BACKGROUND OF THE INVENTION 
     A recliner typically comprises a back rest that rotates downward to lower the user&#39;s back and head from an upright position to more a reclined position. Similarly, recliners also often comprise a deployable ottoman that extends outwardly to present a leg rest that elevates the user&#39;s legs. Certain recliners often also shift the seat box forward to provide room behind the recliner for the lowered back rest. The recliners also often rotate the seat box to elevate the front of the seat box relative to the rear of the seat box to further position the user in a more comfortable reclined position. The back rest, ottoman and seat box of certain recliners are operably linked to a single rotating axle that is rotated by a drive assembly to move the various components such that the moving components can be operated simultaneously. 
     In operation, the drive axle is rotated in a first direction to lower the leg rest while rotating the leg rest of the ottoman into the reclined position. The drive axle can then be shifted forward to shift the seat box forward and extend the leg rest from the seat box of the recliner. The drive axle can then be shifted backwards and rotated in the opposite direction to return the moving components of the recliner to their original positions. 
     In certain recliners, the drive axle is rotated by a traveler moved along a horizontal track perpendicular to drive axle by the drive assembly. The traveler is linked to the drive axle by elongated transfer linkages rotatably affixed to the drive axle via a bracket having an arm extending radially outward from the drive axle. As the traveler moves down the horizontal track, the horizontal motion of the traveler is translated into a pushing or pulling force applied tangentially to the drive axle through the arm to rotate the drive axle. As the drive axle is rotated, the angle between the transfer linkage and the arm collapses as the arm of the drive axle rotates until nearly parallel with the horizontal track. 
     The collapsing angle between the transfer linkage and arm reduces the efficiency of the transfer of force between the traveler and the drive axle, which in turn can place strain on the drive assembly and the linkages. As such there is a need for a means of improving the efficiency of the transfer of force between the traveler and the drive axle. 
     SUMMARY OF THE INVENTION 
     A power mechanism, according to an embodiment of the present invention, can comprise a drive axle, a drive assembly, a horizontal track and a traveler. The drive axle further comprises an arm extending radially outward from the drive axle. The traveler further comprises a transfer linkage rotatably affixed to the traveler at one end and rotatably affixed to the arm at the other end. The arm further comprises a limiter engagable to the transfer linkage as the drive axle rotates to control the relative angle of the arm to the transfer linkage. The drive assembly can further comprise a motor and a worm gear positionable within the horizontal track and rotated by the motor to move the traveler along the horizontal track. 
     As the traveler is moved along the horizontal track by the drive assembly, the transfer linkage translates the horizontal motion of the traveler into a pushing or pulling force tangential to the drive axle applied to the arm to rotate the drive axle a predetermined rotational distance. Rotating the drive axle in a first direction can rotate the leg rest of an ottoman and/or recline a back rest, while rotating the drive axle in the opposite direction can return the ottoman assembly and back rest back to their original positions. Upon fully rotating the drive axle, the arm is positioned generally parallel to the horizontal track such that the pulling or pushing force applied by the transfer linkage is generally transverse to the arm to move the drive axle horizontally in order to shift the seat box forward and extend the leg rest. The angle between the end of the arm and transfer linkage decreases as the drive axle rotates in the first direction until the arm is generally parallel with the horizontal track, which corresponds to the point of least mechanical advantage. 
     As the drive axle is rotated into the first direction, the decreasing angle between the arm and transfer linkage was found to create a spike in the force that must be applied to the traveler to continue the horizontal motion of the traveler. An even greater spike in the applied force was found as the drive axle was rotated in the opposing second direction increasing the angle between transfer linkage and arm. The limiter prevents the angle between the transfer linkage and the arm from decreasing past a predetermined point. The limited “collapse” angle reduces the spike in applied force by increasing the efficiency of the transfer of force from the traveler to the drive axle through the transfer linkage and arm in either rotational direction. In one aspect, the limiter maintains a greater angle between the transfer linkage and arm during the rotation of the drive axle to increase the efficiency of the power mechanism through the entire rotation of the drive axle. The improve efficiency the overall applied force is minimized reducing the strain placed on the linkages as well as the drive assembly. The reduced strain increases the longevity of the linkages and the motor. 
     The above summary of the various representative aspects of the invention is not intended to describe each illustrated aspect or every implementation of the invention. Rather, the aspects are chosen and described so that others skilled in the art can appreciate and understand the principles and practices of the invention. The figures in the detailed description that follow more particularly exemplify these aspects. 
     Still other objects and advantages of the present invention and methods of construction of the same will become readily apparent to those skilled in the art from the following detailed description, wherein only the preferred embodiments are shown and described, simply by way of illustration of the best mode contemplated of carrying out the invention. As will be realized, the invention is capable of other and different embodiments and methods of construction, and its several details are capable of modification in various obvious respects, all without departing from the invention. Accordingly, the drawing and description are to be regarded as illustrative in nature, and not as restrictive. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention can be completely understood in consideration of the following detailed description of various embodiments of the invention in connection with the accompanying drawings, in which: 
         FIG. 1  is a front view of a recliner according to an embodiment of the present invention. 
         FIG. 2  is a partial front view of the recliner depicted in  FIG. 1 . 
         FIG. 3  is a partial perspective view of the recliner depicted in  FIG. 1 . 
         FIG. 4  is a side view of a transfer linkage and arm assembly according to an embodiment of the present invention. 
         FIG. 5A  is a side view of a transfer linkage and arm assembly without a limiter, wherein the traveler is positioned at an initial position. 
         FIG. 5B  is a side view of a transfer linkage and arm assembly with a limiter according to an embodiment of the present invention, wherein the traveler is positioned at an initial position. 
         FIG. 6A  is a side view of a transfer linkage and arm assembly without a limiter, wherein the traveler has moved one inch from the initial position along the track. 
         FIG. 6B  is a side view of a transfer linkage and arm assembly with a limiter according to an embodiment of the present invention, wherein the traveler has moved one inch from the initial position along the track. 
         FIG. 7A  is a side view of a transfer linkage and arm assembly without a limiter, wherein the traveler has moved two inches from the initial position along the track. 
         FIG. 7B  is a side view of a transfer linkage and arm assembly with a limiter according to an embodiment of the present invention, wherein the traveler has moved two inches from the initial position along the track. 
         FIG. 8A  is a side view of a transfer linkage and arm assembly without a limiter, wherein the traveler has moved three inches from the initial position along the track. 
         FIG. 8B  is a side view of a transfer linkage and arm assembly with a limiter according to an embodiment of the present invention, wherein the traveler has moved three inches from the initial position along the track. 
         FIG. 9A  is a side view of a transfer linkage and arm assembly without a limiter, wherein the traveler has moved four inches from the initial position along the track. 
         FIG. 9B  is a side view of a transfer linkage and arm assembly with a limiter according to an embodiment of the present invention, wherein the traveler has moved four inches from the initial position along the track. 
         FIG. 10A  is a side view of a transfer linkage and arm assembly without a limiter, wherein the traveler has moved five inches from the initial position along the track. 
         FIG. 10B  is a side view of a transfer linkage and arm assembly with a limiter according to an embodiment of the present invention, wherein the traveler has moved five inches from the initial position along the track. 
         FIG. 11A  is a side view of a transfer linkage and arm assembly without a limiter, wherein the traveler has moved six inches from the initial position along the track. 
         FIG. 11B  is a side view of a transfer linkage and arm assembly with a limiter according to an embodiment of the present invention, wherein the traveler has moved six inches from the initial position along the track. 
         FIG. 12A  is a side view of a transfer linkage and arm assembly without a limiter, wherein the traveler has moved seven inches from the initial position along the track. 
         FIG. 12B  is a side view of a transfer linkage and arm assembly with a limiter according to an embodiment of the present invention, wherein the traveler has moved seven inches from the initial position along the track. 
         FIG. 13A  is a side view of a transfer linkage and arm assembly without a limiter, wherein the traveler has moved eight inches from the initial position along the track. 
         FIG. 13B  is a side view of a transfer linkage and arm assembly with a limiter according to an embodiment of the present invention, wherein the traveler has moved eight inches from the initial position along the track. 
         FIG. 14A  is a side view of a transfer linkage and arm assembly without a limiter, wherein the traveler has moved nine inches from the initial position along the track. 
         FIG. 14B  is a side view of a transfer linkage and arm assembly with a limiter according to an embodiment of the present invention, wherein the traveler has moved nine inches from the initial position along the track. 
         FIG. 15A  is a side view of a transfer linkage and arm assembly without a limiter, wherein the traveler has moved ten inches from the initial position along the track. 
         FIG. 15B  is a side view of a transfer linkage and arm assembly with a limiter according to an embodiment of the present invention, wherein the traveler has moved ten inches from the initial position along the track. 
         FIG. 16A  is a side view of a transfer linkage and arm assembly without a limiter, wherein the traveler has moved eleven inches from the initial position along the track. 
         FIG. 16B  is a side view of a transfer linkage and arm assembly with a limiter according to an embodiment of the present invention, wherein the traveler has moved eleven inches from the initial position along the track. 
         FIG. 17A  is a side view of a transfer linkage and arm assembly without a limiter, wherein the traveler has moved twelve inches from the initial position along the track. 
         FIG. 17B  is a side view of a transfer linkage and arm assembly with a limiter according to an embodiment of the present invention, wherein the traveler has moved twelve inches from the initial position along the track. 
         FIG. 18  is a bottom view of the recliner depicted in  FIG. 1 . 
         FIG. 19  is a force profile diagram illustrating the force profiles of two linkage assemblies without a limiter according to an embodiment of the present invention and two linkage assemblies with a limiter according to an embodiment of the present invention. 
         FIG. 20  is a partial side perspective view of the swing linkages of the recliner when the ottoman assembly is in its closed position. 
         FIG. 21  is a partial side perspective view of the swing linkages of the recliner when the ottoman assembly is in its extended position. 
         FIG. 22  is a partial side perspective view of the swing linkages of the recliner when the ottoman assembly is in its extended position and the seat back is reclined. 
     
    
    
     While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims. 
     DETAILED DESCRIPTION OF THE DRAWINGS 
     While this invention may be embodied in many different forms, there are described in detail herein specific embodiments of the invention. This description is an exemplification of the principles of the invention and is not intended to limit the invention to the particular embodiments illustrated. 
     As shown in  FIGS. 1-3 , a recliner  20 , according to an embodiment of the present invention, comprises a base  22 , a power mechanism  24  and a seat box  26 . The base  22  further comprises two longitudinal rails  28  each intersected with two end rails  30  to define a generally rectangular frame for supporting the recliner  20 . The base  22  is adapted to be positioned on the ground beneath the recliner  20  and support the recliner  20  during the operation of the recliner  20 . In one aspect, the base  22  can further comprise at least one positioning wheel  32 , wherein the recliner  20  can be rotated such that the recliner  20  rests on the wheels  32  for repositioning of the recliner  20 . 
     The power mechanism  24  further comprises a drive axle  34 , a horizontal track  36 , a traveler assembly  37  and a drive assembly  40 . The drive axle  34  can further comprise a crossbar  35 , which is preferably square in cross-section, and a bracket  41  having an arm  42  secured to the crossbar  35 . The arm  42  extends radially outward from the crossbar  35  such that applying a pushing or pulling force to the arm  42  tangentially causes the drive axle  34  to rotate. The traveler assembly  37  comprises a traveler  38  and at least on transfer linkage  44  rotatably affixed to the traveler  38  via a bracket link  39  at one end and rotatably affixed to the arm  42  at point  43  at the opposite end. Each arm  42  can further comprise a limiter  46  positioned at one end of the arm  42  proximate to the transfer linkage  44 . The limiter  46  can comprise a nut, a rivet, tab, arm or other protrusion extending from the arm  42  such that the limiter  46  can engage the transfer linkage  44 . The drive assembly  40  can further comprise a motor  48  and a worm gear  50  positioned within the horizontal track  36 . The horizontal track  36  is mounted to the end rails  30  such that the horizontal track  36  extends between the end rails  30  in parallel to the longitudinal rails  28 . In one aspect, the horizontal track  36  can also define a first segment  52  and a second segment  54 . 
     In operation, the traveler  38  is operably engaged to the worm gear  50  such that rotation of the worm gear  50  by the motor  48  in a first direction pushes the traveler  38  down the horizontal track  36  in the first direction, while rotating the worm gear  50  in the opposite second direction pulls the traveler  38  in the opposite direction. Moving the traveler  38  in the first direction through the first segment  52  applies a tangential pushing force to the arm  42  to rotate the drive axle  34  in a first direction until the drive axle  34  has rotated a predetermined rotational distance and the arm  42  is generally parallel to the horizontal track  36 . As drive axle  34  is rotated in the first direction, the angle between the arm  42  and the transfer linkage  44  decreases until the limiter  46  engages the transfer linkage  44  to prevent the angle from decreasing below a predetermined angle. In one aspect, the predetermined angle can be at least 60 degrees. In another aspect, the predetermined angle can be at least 150% of the maximum collapsed angle of a transfer linkage  44  without a limiter  46 . Similarly, pulling the traveler  38  in the second direction through the first segment  52  applies a tangential pulling force to the arm  42  to rotate the drive axle  34  in an opposite second direction until the drive axle  34  is returned to the original position. As shown in  FIG. 19 , the greater minimum angle between the arm  42  and the transfer linkage  44  reduces the applied force required to operate the traveler  38  in the reverse direction. 
       FIG. 4  shows a transfer linkage  44  connected to an arm  42  of a bracket  41 . As seen, the arm  42  includes a limiter  46  protruding from the surface of the arm. The limiter can be integral with the arm  42  or be a separate piece protruding from and securing fit in an opening in the arm. As shown, the transfer linkage  44  is rotatably affixed to the bracket link  39  at one end and rotatably affixed to the arm  42  at the other end. The transfer linkage  44  is bent at a predetermined angle. The transfer linkage  44  further comprises a first elongated segment  92 , a second segment  94  extending at an angle from the first elongated segment  92  and a third segment  96  extending at an angle from the second segment in a direction opposite of that of the extension of the second segment from the first elongated segment. 
     As shown in  FIGS. 5A-17B , in one embodiment, the limiter  46  can engage the transfer linkage  44  through a portion of the rotation of the drive axle  34  (starting in the figures in about  FIG. 11B ) to maintain the angle between the transfer linkage  44  and the arm  42  at a greater relative angle to improve the efficiency of force transfer from the traveler  38  to the drive axle  34  throughout the rotation of the drive axle  34 . As shown in the figures, the angle is maintained in the range of about 66 to about 68 degrees. The limiter  46  maintains a greater relative angle through the rotation of the drive axle  34  than the relative angle of a transfer linkage  44  without a limiter  46 . As shown in  FIG. 19 , in this configuration, the increased force transfer efficiency through the rotation of the drive axle  34  dampens the spike in applied force applied by the traveler  38 . 
       FIGS. 5A-17B  show a traveler assembly  37  driving an arm  42  secured to a crossbar  35  along a horizontal track  36  via worm gear  50  and a motor  48 . Each figure shows an inch in longitudinal movement. The embodiment shown shows the motor  48  on the right during the traveler&#39;s  38  movement along the first segment  52  and the second segment  54 . In a further embodiment, the motor  48  would be on the left side of the traveler  38 . As can be seen in  FIGS. 5B-17B , the drive axle  34  substantially stops its rotation in the second segment  54 , during the pulling of the drive axle  34  by the traveler  38 . It can also be seen how the transfer linkage  44  and arm  42  rises up with the drive axle  34  while the seat box  26  rises during its forward movement. 
     As shown in  FIG. 18 , the length of the first segment  52  corresponds to the necessary horizontal travel distance of the traveler  38  to rotate the drive axle  34  the necessary rotational distance. Continuing the movement of the traveler  38  into the second segment  54  maintains the rotation of the drive axle  34  while applying an axial pull force to the arm  42  to move the drive axle  34  horizontally with the traveler  38 . Similarly, moving the traveler  38  in the second direction through the second segment  54  moves the drive axle  34  horizontally in the opposite direction until the traveler  38  reaches the first segment  52 . 
     The seat box  26  further comprises a box frame  60 , at least two forward swing linkage assemblies  62  and at least two rear swing linkages  64 . Each forward swing linkage assembly  62  comprises scissoring linkages  66  movable between a generally bent orientation and a generally elongated orientation. The seat box  26  also further comprises at least one drive axle bracket  68  for rotatably receiving the drive axle  34 . In the embodiment shown, the drive axle bracket further serves as a seat mounting plate. As shown in  FIG. 3 , the two forward swing linkage assemblies  62  are each rotatably affixed at one end to the box frame  60  proximate to the front of the seat box  26  and rotatable affixed to the corresponding longitudinal rail  28  at the opposite end proximate to the front of the base  22 . Similarly, the two rear swing linkages  64  are rotatable affixed at one end to the box frame  60  proximate to the rear of the seat box  26  and rotatable affixed to the corresponding longitudinal rail  28  at the opposite end proximate to the rear of the base  22 . 
     In operation, moving the traveler  38  in the first direction through the second segment  54  moves the seat box  26  forward relative to the base  22 . As shown in  FIG. 1-3 , moving the seat box  26  forward relative to the base  22  extends the scissoring linkages  66  of the forward swing assemblies  62  to elevate front of the seat box  26  as the seat box  26  moves forward. Similarly, moving the traveler  38  in the second direction through the second segment  54  moves the seat box  26  backwards relative to the base  22  and folds the scissoring linkages  66  to return the seat box  26  to the original orientation. In one aspect, the seat box  26  can further define a notch or opening  69  in the rear of the seat box  26  such that the edge of the seat box  26  does not engage the motor  48  as the seat box  26  is moved forward with the lowered rear end. 
       FIG. 19  is a force profile diagram illustrating the force profiles of two linkage assemblies without a limiter  100 ,  110 , according to an embodiment of the present invention and two linkage assemblies with a limiter  112 ,  114 , according to an embodiment of the present invention. As shown, the greater minimum angle between the arm  42  and the transfer linkage  44  reduces the applied force required to operate the traveler  38  in the reverse direction. The increased force transfer efficiency through the rotation of the drive axle  34  dampens the spike in applied force applied by the traveler  38 . 
     As shown in  FIGS. 1-3 , the recliner  20  further comprises an ottoman assembly  70  integrated into the seat box  26 . The ottoman assembly  70  comprises a leg rest  72 , an extension assembly  74  having a plurality of scissoring linkages  76 , and a lever assembly  78 . The scissoring linkages  76  of the extension assembly  74  are adapted to rotate the leg rest  72  such that the leg rest  72  is generally parallel to the top of the seat box  26 . The lever assembly  78  further comprises a transfer linkage  80  and a lever linkage  82 . The lever linkage  82  is operably engaged to drive axle  34  such that rotating the drive axle  34  rotates the lever linkage  82 . The transfer linkage  80  is operably engaged to the lever linkage  82  and extends between the lever linkage  82  and the leg rest  72  to transfer the rotation of the drive axle  34  to a corresponding movement in the leg rest  72  via the extension assembly  74 . In one aspect, the leg rest  72  defines the front the seat box  26 . 
     In operation, moving the traveler  38  through the first segment  52  in the first direction rotates the drive axle  34  in the first direction applying a pushing force on the leg rest  72  through the lever assembly  78  to extend the extension assembly  74  and position the leg rest  72  in an orientation generally parallel to the top of the seat box  26 . Similarly, moving the traveler  38  in the second direction through the first segment  52  rotates the drive axle  34  in the second direction applying a pulling force on the leg rest  72  through the lever assembly  78  to retract the extension assembly  74  to return the leg rest  72  to the original position. In one aspect, the ottoman assembly  74  can be mounted to the seat box  26  on a floating assembly such that the horizontal movement of the drive axle  34  extends the leg rest  72  out from the seat box  26 . 
       FIGS. 20-22  are partial side perspective views of the swing linkages of the recliner when the ottoman assembly is in its closed position, extended position and extended position with the seat back is reclined, respectively. From the closed position to the extended position, the traveler assembly moves through the first segment of the track. As the traveler assembly goes through the second segment, the seat back is reclined. 
     The recliner  20  further comprises a back rest  84  integrated into the seat box  26 . The back rest  84  further comprises a hinge assembly  86  having at least one hinge  88  rotatably engaging the back rest  84  to the seat box  26 . The hinge assembly  86  further comprises at least one positioning lever linkage  90  operably linking the back rest  84  to the drive axle  34 . In operation, rotating the drive axle  34  in the first direction is translated through the lever linkage  90  into a pushing force that reclines the back rest  84  backwards. Similarly, rotating the drive axle  34  in the second direction is translated through the lever linkage  90  into a pulling force that pulls the back rest  84  back to the original seating position. 
     While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and described in detail. It is understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims. 
     
       
         
           
               
             
               
                   
               
               
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     The above references in all sections of this application are herein incorporated by references in their entirety for all purposes. For purposes of interpreting the claims for the present invention, it is expressly intended that the provisions of Section 112, sixth paragraph of 35 U.S.C. are not to be invoked unless the specific terms “means for” or “step for” are recited in a claim. 
     All of the features disclosed in this specification (including the references incorporated by reference, including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. 
     Each feature disclosed in this specification (including references incorporated by reference, any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features. 
     The invention is not restricted to the details of the foregoing embodiment (s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any incorporated by reference references, any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed The above references in all sections of this application are herein incorporated by references in their entirety for all purposes. 
     Although specific examples have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement calculated to achieve the same purpose could be substituted for the specific examples shown. This application is intended to cover adaptations or variations of the present subject matter. Therefore, it is intended that the invention be defined by the attached claims and their legal equivalents, as well as the following illustrative aspects. The above described aspects embodiments of the invention are merely descriptive of its principles and are not to be considered limiting. Further modifications of the invention herein disclosed will occur to those skilled in the respective arts and all such modifications are deemed to be within the scope of the invention.