Abstract:
A platform assembly that attaches to a chair to support a computer peripheral device, e.g. a mouse. The assembly includes a platform, a flexible support arm, a first coupling, and a second coupling. The flexible support arm allows excellent adjustability of the platform that supports the computer peripheral device. The second coupling, a spring-loaded clamp, provides an effective means for coupling the assembly to the chair.

Description:
FIELD OF THE INVENTION  
         [0001]    This invention relates to an accessory for computer peripheral devices. More particularly, it relates to a platform assembly mountable to a chair for use in operating a peripheral device, for example, a computer mouse.  
         BACKGROUND  
         [0002]    The use of personal computers has dramatically increased over the past two decades. With increased usage comes an increase in personal injuries due to incorrect or awkward seating positions assumed by a computer user at a computer workstation. Prolonged computer use in an awkward position can lead to back, neck, shoulder and arm strain.  
           [0003]    Typically, a workstation consists of a desk where a computer and its peripheral devices reside and a desk chair providing seating for a computer user. One approach for solving incorrect seating positions is to relocate the peripheral devices essential to the operation of the computer to the desk chair from the desktop. This allows a computer user to assume a more correct posture in their chair rather than leaning over a desk.  
           [0004]    Several platforms have been developed throughout the years with this solution in mind. For example, Kelly, U.S. Pat. No. 6,123,387 describes a chair with both keyboard and mouse platforms. However, these platforms are bolted to the chair making their removal impractical when needed. Also, the mouse pad does not appear to be adjustable.  
           [0005]    Adkins U.S. Pat. No. 6,027,165 describes a table attachment for armchairs. This table is somewhat cumbersome in the manner that it is also bolted to the chair rendering attachment and removal somewhat time consuming. In addition, there appears to be limited adjustability of the table itself.  
           [0006]    Bourassa U.S. Pat. No. 5,848,773 describes a mouse pad support pedestal consisting of a clamp device for attaching the apparatus to a chair. The clamp is secured to the arm of a chair by tightening a wing nut on a threaded bolt until secure. The support pedestal sits in a groove in the upper portion of the clamp and can only be moved along one axis.  
           [0007]    Nauth Canadian patent application 2,279,333 describes an articulating mouse pad that uses an arm with ball and socket joints for adjustability. This design allows for greater adjustability but requires the loosening of an adjusting screw to allow free movement of the ball and socket joints.  
           [0008]    The present invention is concerned with a chair mounted platform assembly that easily attaches to a chair while allowing for maximum adjustability of the platform while employing a minimum number of parts and user adjustment elements.  
         SUMMARY  
         [0009]    According to the present invention there is provided a platform assembly for attachment to a chair comprising:  
           [0010]    a platform to support a computer peripheral device;  
           [0011]    a flexible support arm;  
           [0012]    a first coupling connecting the platform to one end of the flexible support arm; and  
           [0013]    a second coupling for connecting the other end of the flexible support arm to a chair.  
           [0014]    Preferably, the flexible support arm includes an elongate member of ductile material. This may be a foam tube with a flexible metal cable core and a corrugated plastic sheath. This allows infinite adjustment of the assembly within a range of positions. The use of this support arm configuration provides an inexpensive and simple method of overcoming the adjustability problems of the prior art.  
           [0015]    The second coupling is desirably a spring loaded clamp. Such a clamp allows for quick attachment of the platform to the chair and quick release of the platform from the chair when not needed.  
           [0016]    The first coupling may be an adjustable clamp for securing the support arm to the platform at a position that is adjustable along the platform  
           [0017]    An alternative support arm construction is a flexible metal conduit.  
           [0018]    The platform assembly may also include a moulded handgrip for ergonomic adjustment of the platform. This is particularly useful with the metal support arm. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]    In the accompanying drawings, which illustrate an exemplary embodiment of the present invention:  
         [0020]    [0020]FIG. 1 depicts one embodiment of the platform assembly attached to the armrest of an office chair;  
         [0021]    [0021]FIG. 2 is an enlargement of the first coupling connecting the platform to the support arm in the embodiment of FIG. 1;  
         [0022]    [0022]FIG. 3 is a bottom view of the platform in the embodiment of FIG. 1;  
         [0023]    [0023]FIG. 4 is a plan view of the platform assembly;  
         [0024]    [0024]FIG. 5 is a plan view of the second coupling;  
         [0025]    [0025]FIG. 6 is a side view of the second coupling;  
         [0026]    [0026]FIG. 7 is a side elevation, partially broken away, of a second embodiment of the platform assembly;  
         [0027]    [0027]FIG. 8 is a bottom view of the platform of FIG. 7;  
         [0028]    [0028]FIG. 9 is a bottom view of the platform in the second embodiment; and  
         [0029]    [0029]FIG. 10 is a view along line X-X of FIG. 8.  
     
    
     DETAILED DESCRIPTION  
       [0030]    Referring to the accompanying drawings, FIGS. 1, 2 and  3  illustrate a first embodiment of chair mounted platform assembly  10  attached to a commercially available office chair  11 . The office chair  11  includes a seat  12 , a backrest  13 , armrests  14 , a pedestal  15  and radiating legs  16  supported by castors  17 . The mouse pad  10  consists of a platform  18 , a first coupling  19  connecting the platform to a handgrip  20 , a flexible support arm  21  and a second coupling  22  connecting the flexible support arm to one of the armrests  14  of the office chair.  
         [0031]    The first coupling  19  is comprised of a fastening knob  31  and a threaded bolt  32 . The threaded bolt  32  is secured to the handgrip  20  by screwing into a bore in the handgrip. The fastening knob has a similar bore that allows it to be threaded onto the threaded bolt. The head of the threaded bolt sits in a channel created by two parallel rails  33  that are fastened to the underside of the platform  18  with screws  34 . The fastening knob  31  is turned until the knob and the head of the bolt pinch the railings creating enough tension to immobilize the platform  18 . Loosening and tightening the fastening knob allows rotation of the platform around the threaded bolt and movement along the rails  33 .  
         [0032]    The handgrip  20 , as shown in FIG. 1, is shaped to conform to the user&#39;s hand, extending through an angle from the support arm to the first coupling, with ridges to define finger grips so that the whole can be used as a pistol grip for orienting and positioning the platform as desired.  
         [0033]    The flexible support arm  21  includes a section of a commercially available flexible metal conduit of the type formed from a helically wound continuous metal strip. The support arm is shapable allowing infinite adjustment of the platform assembly within a range limited by the bending radius of the arm. The arm is also rigid enough that once adjusted the platform will remain in position under the applied loads until readjusting is desired. One end of the arm  21  fits into a hollow in the handgrip  20 . The other end of the flexible shaft is attached to the second coupling  22 .  
         [0034]    The second coupling  22  is a spring loaded clamp. The clamp consists of two clamp arms  51 , a pivot pin  52 , a torsion spring  53 , and two resilient pads  54 . Referring to FIG. 5, the two clamp arms are held together by the pivot pin. The torsion spring ends  55  bear on the clamp arms providing the necessary force for the operation of the clamp. The resilient pads  54  prevent marring the finish of the chair&#39;s armrest  14 . The spring clamp provides for easy attachment and release of the platform assembly to and from the chair.  
         [0035]    In FIG. 4, there is a top-down view of the platform  18 . The surface  41  is recessed to accommodate a textured surface for operation of the computer peripheral device. In addition, the platform includes a wrist-supporting pad  40  in an effort to maintain ergonomic functionality.  
         [0036]    The handgrip  20 , as shown in FIG. 1, is shaped to conform to the user&#39;s hand, extending through an angle from the support arm to the first coupling, with ridges to define finger grips so that the whole can be used as a pistol grip for orienting and positioning the platform as desired.  
         [0037]    The flexible support arm  21  includes a section of a commercially available flexible metal conduit of the type formed from a helically wound continuous metal strip. The support arm is deformable and cane shaped as desired, allowing infinite adjustment of the platform assembly within a range limited by the bending radius of the arm. The arm is also rigid enough that once adjusted the platform will remain in position under the applied loads until readjusting is desired. One end of the arm  21  fits into a hollow in the handgrip  20 . The other end of the flexible shaft is attached to the second coupling  22 .  
         [0038]    [0038]FIGS. 7 through 10 illustrate a second embodiment of the assembly with modified support arm and first coupling configurations. In this embodiment, the platform assembly  60  includes the platform  18 , a first coupling  62  connecting the platform to a flexible support arm  64  and the second coupling  22  connecting the flexible support arm to one of the armrests  14  of the office chair.  
         [0039]    The first coupling  62  includes an inverted T rail  66  on the bottom side  68  of the platform  18 . and a channel  70  engaging the rail and mounted on the end of the handgrip  20 . The bottom side of the rail  66  has one side formed as a rack  72 , with a set of teeth  74 . Beside the rack is a relieved section  76 . A transverse pin  78  extends across the channel  70 , below the rail. The pin extends beyond one side of the rail and has a head  80  on that end. An internal spring  81  biases the pin outwardly. Pin  78  carries a block  82 , with teeth  84  on its upper side, configured to engage the teeth  74  of the rack  72  when the pin is displaced outwardly from the one side of the channel by the spring  81 , thus locking the rail  66  and the platform to the handgrip  20 . Pressing on the pin head  80  to move the pin  78  inwardly disengages the teeth  84  from the rack  72 , allowing the channel  70  to slide along the rail  66  to adjust the platform position on the handgrip.  
         [0040]    The flexible support arm  64  includes a section of thick walled foam tube  86  with a wound steel cable core  88  and a corrugated plastic sheath  90 . The support arm may be deformed to allow infinite adjustment of the platform assembly within a range limited by the reach and bending radius of the arm. The arm is also stiff enough that the platform, once adjusted, will remain in position under the applied loads until readjustment is desired. One end of the arm  64  is shaped to form the handgrip  20 . The other end of the flexible shaft is attached to the second coupling  22 .  
         [0041]    While particular embodiments of the present invention have been described in the foregoing, it is to be understood that other embodiments are possible within the scope of the invention. Thus, for example, the platform assembly could comprise a flexible support arm of various forms, including an arm formed entirely of plastic material or of the type described in U.S. Pat. Nos. 5,517,392 and 5,521,803. The adjustment mechanism for adjusting the position of the platform on the arm may use an internal ball detent rather than the clamp or latch mechanisms described. Instead of the armchair used in the exemplary embodiment, the platform assembly could be mounted to an armchair having an armrest with center support post. The invention is therefore to be considered limited solely by the scope of the appended claims.