Abstract:
A chair adjustment mechanism suitable for use in vehicles including aircraft. The mechanism allows the chair to be easily moved in a horizontal place and locked into any position within a boundary of this plane. This movement includes swivel movement in 360 degrees.

Description:
BACKGROUND  
         [0001]    1. Field  
           [0002]    This invention relates to the field of adjustable chairs for use in vehicles, and more particularly to a chair having a mechanism to control and facilitate lateral, longitudinal and swiveling movement.  
           [0003]    2. Description of the Prior Art  
           [0004]    Vehicles used in transportation including commercial and private aircraft are equipped with chairs for seating passengers for trips of varying length. A chair with a greater range of motion, such as forward and aft, lateral and swivel movement along with the capability of locking into the new positions provides greater comfort to the passenger especially over longer journeys. Chairs in this context can be subject to turbulent conditions. Many chairs used in these conditions use tracks to allow movement in conjunction with locking pins to maintain position. This configuration is inconvenient to adjust or requires complicated automation. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0005]    The invention is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean at least one.  
         [0006]    [0006]FIG. 1 depicts a chair with an adjustment mechanism.  
         [0007]    [0007]FIG. 2 depicts an adjustment mechanism.  
         [0008]    [0008]FIG. 3 depicts the spindle assembly of an adjustment mechanism.  
         [0009]    [0009]FIG. 4 depicts the brake assembly of an adjustment mechanism. 
     
    
     DETAILED DESCRIPTION  
       [0010]    [0010]FIG. 1 depicts one embodiment of the invention, wherein parts are indicated by reference numerals, showing an adjustable chair  20  that has a seat back  22  attached to a seat base  24  and seat support  26 . The seat support structure  26  contains the seat pan which houses an adjustment mechanism. The seat support  26  rests over chair base  28 . When the adjustment mechanism is in an unlocked position the seat support  26  can move forward, aft, and laterally in relation to the chair base  28 . Movement of the seat support  26  is bounded because the spindle assembly of the adjustment mechanism is situated through the bottom of the seat pan and seat support  26  into the chair base  28 . The spindle assembly includes a brake disk  30 , a bottom assembly nut  32  and a brake pad  34 .  
         [0011]    In one embodiment, when the adjustment mechanism is in the locked position, the seat support  26  is unable to move in relation to the chair base  28 . The adjustment mechanism clamps the seat support  26  and seat pan to the chair base  28 . The seat support  26  is held in place by the frictional contact of the brake pad  34  with the underside of the top of the chair base  28 .  
         [0012]    In one embodiment, a handle mechanism  36  is housed in the seat base  24 , an arm rest, or similar structure attached to the seat. The handle mechanism  36  is connected to a cam in the adjustment mechanism by a cable. In one embodiment, the cable is {fraction (3/16)} inch wire rope in a sheath of flexible material. A mechanical advantage may be incorporated into the handle mechanism to facilitate ease of use in actuating the adjustment mechanism by the user.  
         [0013]    In another embodiment, an electronic controller is placed in the seat base, attached structure, or the like to control the adjustment mechanism. In one embodiment, the electronic controller activates motor to move the adjustment mechanism from a locked to an unlocked position.  
         [0014]    In an exemplary embodiment, a microcontroller receives input from the seat user via a switch in the armrest. When the user switches to an unlock position, the microcontroller activates a stepper-motor attached to a spindle and brake assembly to lower the spindle and brake assembly. When the user switches to a lock position, the microcontroller activates the stepper-motor to raise the spindle and brake assembly. In one embodiment, the stepper-motor drives a cam or camshaft to lower and raise the spindle and brake assembly. This embodiment employs the mechanical advantage of the cam or camshaft to adjust the spindle and brake assembly allowing for a more energy efficient or less expensive stepper-motor to be used.  
         [0015]    This embodiment of the invention allows a user to position the seat by moving the seat relative to the base in any horizontal direction while in the unlocked state within the boundary defined by the chair base  28  within which the spindle and brake disk  30  are confined.  
         [0016]    When the chair is set in the lock state, the brake disk clamps the chair base  28  to the seat support  26  creating a friction lock. This provides a secure chair for use in transportation including for use in air transport.  
         [0017]    It will be understood that the mechanical structures of the chair  20  have been shown without upholstery and similar components of the chair in order that the described components can be depicted with clarity.  
         [0018]    [0018]FIG. 2 depicts an embodiment of the invention where a guide  103  is attached to seat pan  101  by bolts, screws, or the like. In another embodiment seat pan  101  is designed to incorporate structures equivalent to the guide  103 . An adjustment nut  108  with dowels attached on opposite ends of the nut is placed within the guide  103  so that the dowels are slidably disposed in the cut outs of the guide  103 . The guide  103  is attached to the seat pan  101  through a cut out in the bottom of the seat pan  101 . Attached to the bottom of the guide  103  covering the cut out in the bottom of the seat pan  101  is a shaft (not shown).  
         [0019]    In one embodiment, links  105  are attached via a socket to the dowels of top adjustment nut  108 . The links  105  are also attached to glide blocks  106  by a male type attachment that rests in the hole in the upper section of the glide blocks  106 . The glide blocks  106  are slidably disposed in a track formed in the seat pan  101 . The glide blocks  106  have a range of motion on the track from a position approximately centered beneath the adjustment nut  108  dowels in the guide  103  to a position close to the camshaft  102 .  
         [0020]    In one embodiment, two torsional springs  104  are attached to the links  105  and the guide  103  so as to exert a force on the glide blocks  106  in the direction of the position near the camshaft. One torsional spring  104  is attached to each link  105  to provide a force against each glide block  106 . In another embodiment the torsional spring  104  is connected directly to the glide block  106 . It would be understood that other types of springs or like devices designed to exert a force against the glide blocks  106  toward their positions near the camshaft could be used in a variety of alternate embodiments of the invention. The force of spring mechanism  104  pushes the glide blocks  106  to their position near the camshaft which in turn applies force to the dowels of the adjustment nut  108  lowering the nut to the lower end of the cut out of the guide  103  thereby placing the adjustment nut  108  and the attached spindle and brake disk  30  in the unlocked position.  
         [0021]    In another embodiment, the two torsional springs  104  are attached to the links  105  and the guide  103  so as to exert a force on the glide blocks  106  in the direction of their centered position. It would be understood that other types of springs or like devices could be used to exert a force on the glide blocks  106  toward their centered positions. The torsional springs  104  push glide blocks  104  to their centered position which lifts the top adjustment nut  108  to the upper end of the cutout of the guide  103 , thereby placing the adjustment mechanism in the locked position.  
         [0022]    In one embodiment, the adjustment device is moved to the unlocked state by movement of a handle  36  by a user. The handle  36  is attached by a cable  109  to a cam  107 . The cam  107  is attached to the seat pan  101  and a camshaft  102  so that the cam  107  can rotate about an axis perpendicular to the movement of the glide blocks  106 . The cam  107  is rotated away from the guide  103  by activation of the handle  36 . This movement of the cam  107  turns the camshaft  102  in a proportionate manner. Attached to the camshaft  102  at each end are glide cables  110 . The glide cables  110  are attached one to each glide block  106 . When the camshaft  102  is turned by activation of the handle mechanism  36  glide cables  110  pull the glide blocks  106  from their center position to a position near the camshaft  102 .  
         [0023]    In one embodiment, movement of the camshaft releases the pull of the glide cables on the glide blocks  106  allowing a compression spring to push the top adjustment nut  108  and attached spindle to a higher position in the guide cutout where the brake disk  30  and brake pad  34  are in contact with the chair base  28  preventing the seat support  26  from moving in relation to the chair base  28 . This results in the glide blocks  106  being in the centered position.  
         [0024]    In another embodiment, placement of the handle  36  in the lock position releases pressure on the cam  107 . The torsional springs  104  pull the guide blocks  106  to the centered position raising the adjustment nut  108  and attached spindle to the lock position. The glide cables  110  are pulled by the glide blocks  106  thereby turning the camshaft  102  and cam  107  to their respective locked positions. In this embodiment, placement of the handle  36  in the unlocked position rotates the cam  107  and the camshaft  102  which pulls glide blocks  106  toward the camshaft  102 . This allows the compression spring to pull the top adjustment nut  108  and attached spindle to a lower position in the guide cutout where the brake disk  30  and brake pad  34  are not in contact with the chair base  28  allowing the seat support  26  to move in relation to the client base  28 .  
         [0025]    In one embodiment, the adjustment nut  108  is screwed to the top of a spindle. Adjustment screws  111  serve as a secondary means of locking the spindle into the top adjustment nut  108 . The adjustment screws  111  maintain the position of this adjustment nut  108  in relation to the spindle thereby allowing the position of the brake disk  30  in relation to the seat pan  101  to be maintained even if the brake disk  30  or brake pad  34  is removed temporarily from the spindle assembly. Maintaining the position of the top adjustment nut  108  during the stress and vibration of travel and use of the chair is important to the function of locking the chair in a position. To lock a chair in a position, the brake assembly comes into contact with the chair base  28 . In one embodiment, the distance between the bottom of the seat pan and the top of the brake disk  30  or brake pad  34  must be short enough to create contact when in the locked position but not in the unlocked position. The adjustment screws  111  prevent the top adjustment nut  108  from moving its position relative to the spindle thereby maintaining the distance between the top adjustment nut  108  and brake disk  30 . This also preserves the clamped dimension, the necessary minimal distance between the top adjustment nut  108  and brake disk  30  or brake pad  34  to achieve a friction lock in the lock position. Also, the adjustment screws  111  ensure that the adjustment mechanism remains properly adjusted through vibration loads and stress typical in vehicles and during use of the chair.  
         [0026]    [0026]FIG. 3 depicts one embodiment of a spindle assembly of the invention where a spindle  206  is placed within the shaft  208 . The top of the spindle  206  is threaded to be screwed into a doweled adjustment nut  108 . The inner circumference of the shaft  208  is wide enough to accommodate a compression spring  205  placed around the spindle  206  within the shaft  208  except near the bottom shaft opening where the inner circumference of the shaft  208  narrows to roughly match the outer circumference of the spindle  206 . The compression spring  205  attaches at one end with the bottom of the shaft  208 . At the other end, the spring  205  attaches to the top adjustment nut  108 . The compression spring  205  is in a compressed position when the adjustment mechanism is in the unlocked position exerting an upward force on the top adjustment nut  108 . When the mechanism is in the locked position, the compression spring  205  is expanded upward with the top adjustment nut  108 .  
         [0027]    In another embodiment, the compression spring  205  is in a rest position when the adjustment mechanism is in the unlocked position. When the adjustment mechanism is in the locked position, the compression spring  205  is stretched upward with the top adjustment nut  108 , thereby exerting a downward force on the spindle  206  and top adjustment nut  108 . Alternatively, when the adjustment mechanism is in the unlocked position, the compression spring  205  may be stretched to assert a downward force that is not able to overcome the upward force generated by the torsional spring  104 .  
         [0028]    [0028]FIG. 4 depicts an embodiment of the brake disk assembly of the invention where brake disk  30  is secured between bottom adjustment nut  32  and a middle portion  340  of the spindle  206 . The bottom end  322  of the spindle  206  is threaded to accommodate a bottom assembly nut  32 . The outer circumference of the bottom portion  322  of the spindle  206  including the threaded portion  324  and a small portion just below the threaded portion  324  including openings to channels for dowels  309  is narrower than the middle portion  340  of the spindle  206 . The middle portion  340  of the spindle  206  has a greater exterior circumference than the bottom end portion  322 . In one embodiment, the bottom assembly nut  32  has a set of channels running through the center of the nut wherein a removable dowel  309  can be placed. The spindle  206  has a complementary set of channels which open on opposite sides of the spindle  206  to allow the removable dowel  309  to pass through the spindle  206 . The dowels  309  are placed through the nut  32  and spindle  206  to prevent the nut  32  from moving relative to the spindle  206  after it has been placed on the spindle  206 . These dowels preserve the bottom assembly nut  32  position and thereby the place of the brake disk  30  relative to the top  344  of the spindle  206  by preventing the brake disk  30  from moving away from the top of the spindle during the stress and vibration of travel and use.  
         [0029]    In one embodiment, the brake pad  34  is composed of a metal core structure covered by an abrasive material. In an exemplary embodiment, the metal core structure is an aluminum honeycomb structure. Suitable abrasive materials include rubber, neoprene rubber, cork or similar materials.  
         [0030]    In the foregoing specification, the invention has been described with reference to specific embodiments thereof. It will, however, be evident that various modifications and changes can be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.