Abstract:
In one aspect, the subject embodiments are directed to a seat that includes a seat bottom and a seat back, wherein the seat back is pivotable with respect to the seat bottom about one or more pivots. A linkage assembly is employed that is coupled to each of the one or more pivots. The linkage assembly includes a linking component that has a first location mounted to the seat bottom and a second location mounted to the seat back. A cam is coupled to the seat back location, wherein a dowel is permanently affixed to the cam. An end distal from the cam, a pin extends perpendicularly from the dowel and is angled at between 20 and 70 degrees upward from a plane formed by an arm channel.

Description:
BACKGROUND 
     In conventional assemblies, seats are designed to provide a level of comfort to a user by allowing a certain degree of reclination of a seat back relative to a base. To provide further comfort, the seat can include armrests which allow a user to place his or her arms thereon. Many prior art designs, however, do not provide adapt the armrests when the seat is placed in a reclined position. Instead, the armrests can maintain substantially a perpendicular disposition relative to the seat back wherein the user&#39;s arms are pointed upward in awkward position thereby causing discomfort 
     In order to overcome this shortcoming, self-leveling armrests have been employed for use with reclining seats. These self-leveling deigns allow the armrest to remain substantially parallel to the seat base regardless of the position of the seat back. Conventional self-leveling armrest designs, however, suffer from complex designs and resulting exorbitant costs. Accordingly, such prior art designs are impractical for use in the market place as the cost is too great. Moreover, these designs integrate the self-leveling armrest completely with the frame of the seat thereby forcing a manufacturer to build entire seat assembly to provide any variance in armrest features. Moreover, the manufacturer is forced to sell a single model which is incapable of modification or modularity. As a result, a customer or end user is unable to choose from one or more custom solutions. 
     In view of the above deficiencies, seat assemblies are needed that can accommodate modular armrest designs. 
    
    
     
       BRIEF SUMMARY OF THE DRAWINGS 
         FIG. 1  is a perspective view of a self-leveling linkage assembly. 
         FIG. 2  is a perspective view of the self-leveling linkage assembly in association with a seat frame and provides an exploded of an arm channel configured to be disposed thereon. 
         FIG. 3  is a detail view of a portion of  FIG. 2 . 
         FIG. 4A  is a perspective view of an arm channel bracket that is utilized with the self-leveling arm assembly. 
         FIG. 4B  is an elevation view of an arm channel bracket that is utilized with the self-leveling arm assembly. 
         FIG. 5  is a perspective view of the self-leveling linkage assembly in association with a seat frame and provides an exploded of an arm channel configured to be disposed thereon. 
         FIG. 6  illustrates the self-leveling linkage assembly after installation onto a seat frame. 
         FIG. 7  is a front perspective view of a self-leveling arm rest system that is installed on a seat frame. 
         FIG. 8  is a rear perspective view of a self-leveling arm rest system that is installed on a seat frame. 
         FIG. 9  is a perspective view of a linkage system used with a self-leveling arm rest system that is installed on a seat frame. 
         FIG. 10  is a rear perspective view of a self-leveling arm rest system that is installed on a seat frame. 
         FIG. 11  is a rear perspective view of a self-leveling arm rest system that is installed on a seat frame. 
     
    
    
     SUMMARY OF THE INVENTION 
     In one aspect, the subject embodiments are directed to a seat that includes a seat bottom and a seat back, wherein the seat back is pivotable with respect to the seat bottom about one or more pivots. A linkage assembly is employed that is coupled to each of the one or more pivots. The linkage assembly includes a linking component that has a first location mounted to the seat bottom and a second location mounted to the seat back. A cam is coupled to the seat back location, wherein a dowel is permanently affixed to the cam. An end distal from the cam, a pin extends perpendicularly from the dowel and is angled at between 20 and 70 degrees upward from a plane formed by an arm channel. 
     DETAILED DESCRIPTION 
     The subject invention is utilized to provide an armrest on a seat which is self leveling. In this manner, the armrest can maintain a position that is substantially parallel to the plane of a seat. The subject self-leveling arm assembly can be employed, in one embodiment, as a modular add-on to an existing structure. As a result, a manufacturer can easily provide a plurality of seat models, wherein each model offers particular desired features. 
       FIG. 1  is a perspective view of a self-leveling arm assembly  106 . The assembly  106  is comprised of a main link  14  coupled to a lower bracket  12  and a dowel subassembly  42 . Each of the lower bracket  12  and the subassembly  42  are coupled to the main link  14  via securement components. In one example, the securement components are pin  30  and pin  32  which are each inserted into a through-hole to facilitate rotation of the corresponding component. In this manner, the pin  30  creates a pivot between the main link  14  and the lower bracket  12 . Similarly, the pin  32  creates a pivot between the main link  14  and the dowel subassembly  42 . 
     The dowel subassembly  42  is comprised of a dowel  16  which is coupled to a cam  20 . The cam  20  is in turn coupled to the main link  14  via the pin  32  in a rotatable fashion as described above. In one embodiment, the dowel  16  is welded to the cam  20  to permanently affix the dowel  16  and prevent rotation thereof. A pin  18  is mounted substantially perpendicular to the main axis of the dowel  16  on a side distal from the cam  20 . As the dowel  16  is permanently affixed to the cam  20 , the location of the pin will also maintain a particular rotational angle. In one aspect, the location of the pin  18  is specified relative to the plane of the base and/or armrest. The pin  18  can have an angle of between 0.1 and 90 degrees to facilitate self leveling of an arm channel (not shown) affixed to the self-leveling arm assembly  106  via the dowel subassembly  42 . In another embodiment, the pin  18  can be press fit into the dowel  16  in order to secure the pin. In addition, the dowel  16  further comprises a hole  24  that can accommodate a pin (not shown) to prevent movement of the assembly  106  relative to a seat frame 
     The lower bracket  12  includes four holes to accommodate securement components. Two holes  56  and  58  accommodate the pin  30  to couple the lower bracket  12  to the main link  14 . In addition, holes  60  and  62  are utilized to accommodate fastening devices (not shown) to mount the self-leveling arm assembly  106  to the base of a seat frame. 
       FIG. 2  illustrates the self-leveling arm assembly  106  employed with a seat frame  100 . In this embodiment, the self-leveling arm assembly is shown in both a left hand and right hand configuration to accommodate respective left arm channel and right arm channels of the seat frame  100 . The seat frame  100  contains a back frame  102 , a base frame  104 , a left hand self-leveling arm assembly  106 , and a right hand self-leveling arm assembly  108 . A left arm channel  110  is coupled to the back frame  102  via the left hand self-leveling arm assembly  106 . A right arm channel  112  is coupled to the back frame  102  via the right hand self-leveling arm assembly  108 . 
       FIG. 3  is a detail view of  FIG. 2  showing the left-hand self-leveling arm assembly  106  coupled to the seat frame  100 . It is to be appreciated, however, that the right hand self-leveling arm assembly is coupled to the seat frame symmetrically to the seat frame  100  as described herein. Fastening devices  120  and  122  are disposed in holes  60  and  62  respectively. In one embodiment, the fastening devices  120  and  122  are bolts, which are threaded and coupled to nuts  124  and  126  to secure the lower bracket  12  to the seat frame  100 . Similarly, a fastening device  140  is utilized to secure the dowel subassembly  42  to the seat frame via a bracket  160 . The bracket  160  is mounted to a support  170  of the back frame  102  via any known method. In this manner, the bracket  160  can be introduced at substantially any point in the assembly process during manufacture of the seat frame  100 . The bracket  160  includes a keyhole  150  that allows the dowel subassembly to be inserted therein. The keyhole  150  contains a rectangular portion coupled directly to a circular portion, wherein the circular portion is substantially the same size as the diameter of the dowel  16 . The rectangular portion allows the pin  18  to be inserted therethrough. 
     Once the dowel subassembly is inserted through the bracket  160 , the fastening device  140  can be used to couple the dowel subassembly  42  to the bracket  160  and to the arm  110 . To facilitate appropriate tension of the fastening device  140 , washers  142  and  146  and a spacer  144  can be employed. In one aspect, the spacer  144  is made of a nylon or equivalent material. The washers  142  and  146  and the spacer  144  can allow minimal friction upon rotation of the arm channel  110  around a pivot point  148 . In one aspect, the fastening device  140  is a screw which is driven into a threaded hole  164  at the end of the dowel  16 . Once the dowel subassembly  42  is inserted through the bracket and coupled to the arm through the bracket  160  and coupled to the arm  110 , a pin  130  can be inserted to prevent movement of the arm  100  and the arm and the pin  18  toward the interior of the seat frame  100 . 
       FIGS. 4A and 4B  illustrate the arm  110  in greater detail. The arm  110  includes an arm channel stopper  200  which is utilized to engage with the pin  18  coupled to the dowel  16  to allow rotational movement of the arm  110  commensurate with the angle of recline of the back frame  102  in relation to the base frame  104  of the seat  100 . The stopper  200  is comprised of an upper stopper element  220  and a lower stopper element  222  which are disposed at particular angles relative to the dowel  16  inserted through the hole disposed therebetween. In one embodiment, the upper stopper element  220  and the lower stopper element  222  are disposed at substantially 90 degrees from each other, wherein the upper stopper element and lower stopper element are approximately 45 degrees rotated from the datum  234 . In operation, the upper stopper element  220  rests on top of the pin  18  of the dowel subassembly  42 . The arm  100  can be lifted up parallel to the back frame  102  wherein the lower stopper element  222  will stop the rotation of the arm  100  as it engages the pin  118 . In this manner, a passenger can be afforded access into and out of the seat by moving the arm  110  out of the way. The arm rest can be subsequently placed downward and remain substantially parallel to the seat base regardless of the angle of reclination between the back frame  102 . 
       FIG. 5  shows an exploded view the left hand self-leveling arm assembly  106  after it has been secured to the base frame  104  via the fastening device  120  and  122 . The left  110  is exploded showing the fastening device  140  employed to couple it to the seat frame  100 . As illustrated, the pin  18  is located at an angle of around 45 degrees although it is contemplated that the rotational location of the pin can be anywhere from 0.1 to 90 degrees in relation to the plane of the base frame  104  and/or the arm channel  110 .  FIG. 6  is a front view showing the left hand self-leveling arm assembly  106  after it is installed onto the seat frame  100 . As shown, the bracket  160  is introduced to facilitate the coupling of the self-leveling arm assembly  106  to the seat  100 . 
       FIG. 7  is a front perspective view of an embodiment  300  of the self-leveling arm system that includes an arm channel  302  that is coupled to a base frame  104  via a linkage system  380 . The linkage system  380  includes a tube collar  322  that is fixably secured to the arm channel  302  to accept a first end of a dowel  308 , which is seated therein proximate to the arm channel. A second end of the dowel  308  is fixably secured to a cam  310  whereby the rotation of the dowel  308  initiated by rotational movement of the arm channel  302  results in rotation of the cam  310  in either a clockwise or counter-clockwise direction commensurate with an up or down rotation of the arm channel  302 . Alternatively, the movement of the back frame  102  relative to the base frame  104  (e.g., caused by reclination of the user) can pull on the linkage assembly  380  thereby pulling the cam downwardly toward the front of the seat. This movement of the cam will cause the dowel  308  to rotate thereby rotating the arm channel  302  to remain substantially parallel with the base frame  104 . 
     A rigid arm  306  has a first end and a second end, wherein the first end is pivotally secured to the cam via rivet  352  or other suitable fastening device. The second end of the rigid arm  306  is pivotally secured to the base frame  104  via a bracket  342 . Pivotal securement is facilitated via rivet  354  or other suitable device to interface the rigid arm  306  with the bracket  342 . The bracket  342  in turn is permanently fixed to the base frame  104  utilizing one or more fastening devices, such as a nut, a bolt, a rivet, etc. 
     In order to provide support for the linkage system, a rear frame upright  304  can be employed to dispose the dowel  308  there-through. In one example, the rear frame upright is disposed between the cam  310  and the tube collar  322 , although substantially any arrangement is contemplated within the scope of the subject embodiments. Placing the dowel  308  through the rear frame upright  304  provides additional structural support to the linkage system  380  and facilitates stable and consistent rotational motion of the arm channel  302  relative to the base frame  104 . Additional structure support may be realized via the use of a bracket  318  is mounted onto the arm channel  302  and substantially surrounds the tube collar, as illustrated. The bracket  318  can contain an aperture (not shown in  FIG. 7 ) to accommodate the dowel  308  to pass there-through for seating within the tube collar  322 . A pin  326  can be placed within the dowel to mitigate lateral motion of the dowel  308 . 
     A bolt  332  can be disposed within the dowel  308  orthogonally to the longitudinal access of the dowel  308 . When the arm channel  302  is rotated, the bolt  332  can make contact with a forward stop  328  within the bracket  318  to prevent further rotational motion of the arm channel  302 . Similarly, a rear stop (not shown in  FIG. 7 ) can be employed to prevent rotational motion in the opposite direction beyond a certain range. In an alternate embodiment, as shown in  FIG. 8 , the tube collar  322  can have a slot  338  cut, wherein the bolt  332  is employed to secure the dowel to the tube collar and to limit rotational motion of the dowel  308  and arm channel  302 . 
     In order to provide a self-leveling function, the linkage system  380  is designed to allow the arm channel  302  to remain substantially parallel to the base frame  104  regardless of the position of reclination of a user within the seat  300 . As the rear frame  102  of the seat  300  is reclined (e.g., displaced away from the forward edge of the arm channel), the arm  306  pushes forward thereby rotating the cam  310  accordingly to modify the longitudinal position of the arm channel  302 . This motion is facilitated by the pivotal securement of 352 and 354 in two locations at the cam  310  and at the seat base frame  104 . In an embodiment, the arm  306  is angled wherein a first element  454  and a second element  456  are disposed at an obtuse angle relative to one another. This slight break in the rigid arm  306  can facilitate a greater range of motion for the arm upon user reclination and can provide added strength to the structure. 
       FIG. 8  illustrates a rear perspective view of the linkage system  380  that illustrates the bolt  332  and dowel aperture  422  utilized therewith. Once the dowel is placed within the bracket aperture  428  and seated within the tube collar  322 , the bolt  332  can be fixed in the dowel aperture  422  and tightened to a predetermined torque level. In an alternate embodiment, slot  338  is created within the tube collar  322  whereby the bolt  332  is fastened through the slot  338  and into the aperture  422  for securement of the dowel therein. The torque level of the bolt  332  securement can be commensurate with the amount of force required to rotate the arm channel  302  in space. Thus, a bracket  318  with a front stop  328  and a rear stop  330  can be employed with the bolt  332  disposed within the aperture  422  to define a range of motion for the arm channel  302 . Alternatively, the bracket  318  is not used. Instead, a slot  338  is employed to define the range of motion of the arm channel  302  in space and force necessary for movement thereof. As a user pushes back on the rear frame  102 , a piston  414  is engaged to slow displacement of the seat back frame  102 . The piston  414  is fixably secured to the seat base frame  104  via a bracket  348  and pin  418  as shown. 
       FIG. 9  shows the linkage system  380  without the surrounding seat structure. In this illustration, the dowel  308  includes the dowel aperture  422  and a pin aperture  464  utilized to accommodate a role pin to prevent lateral movement of the linkage system relative to the rear frame  102 . Also shown are a first fin  454  and a second fin  456  that extend from the rigid arm  306  to provide additional structural support. The bracket  342  is coupled to the linkage arm  306  via a fastening device  304 . An aperture  470  is utilized to accommodate a fastening device to fixably secure the linkage system  380  to the base frame  104 .  FIGS. 10 and 11  show the linkage system within a seat frame wherein  FIG. 10  illustrates the linkage system within the rear frame upright  304  and  FIG. 11  shows a linkage system with the rear frame upright  304  removed to provide additional clarity to the subject embodiments. 
     The examples have been described with reference to the preferred embodiment. With reference to exemplarily embodiments. Obviously, modifications and alterations will occur to others upon reading and understanding the proceeding detailed description. It is intended that the exemplary embodiment be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims where the equivalence thereof.