Patent Publication Number: US-7707946-B2

Title: Adjustable work surface support

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This application claims the benefit of U.S. Provisional Application No. 60/515,645, filed Oct. 31, 2003, which is incorporated herein by reference. 

   FIELD OF THE INVENTION 
   The invention relates generally to adjustable work surfaces. More particularly, the invention relates to an adjustable work surface support mechanism for mounting a secondary work surface to a primary work surface. 
   BACKGROUND OF THE INVENTION 
   In the field of traditional support mechanisms, there are many different types of adjustable work surface support mechanisms, such as the one described in U.S. Pat. No. 5,513,579 to Allan. However, such support mechanisms generally require a large number of individual parts, making it expensive to manufacture and assemble. 
   Furthermore, there are other support mechanisms which are used in computer desks. The support mechanisms allow an adjustable secondary work surface, which generally holds a keyboard, to be manually moved from a first position to a second position in the vertical direction, in reference to a primary work surface which holds a computer monitor. However, many of these support mechanisms include parts underneath the secondary work surface which may cause injury when a user&#39;s legs coming into contact against it or a user&#39;s hands when they try to adjust the height of the secondary work surface. 
   It is, therefore, desirable to provide an adjustable work surface support which overcomes some of the problems of the prior art. 
   SUMMARY OF THE INVENTION 
   It is therefore an object of the invention to provide an adjustable work surface support mechanism which provides a robust support, which can be easily and repeatably pivoted so that a secondary work surface may be moved with respect to a primary work surface, while keeping the construction simple and more cost effective to manufacture and assemble. 
   In one aspect of the present invention, there is provided an adjustable work surface support for use with a primary work surface and a secondary work surface comprising primary work surface connecting means; secondary work surface connecting means; a parallelogram link support comprising a pair of parallel arms, each arm attached at one end to the primary work surface connecting means to define a first axis and a second end attached to the secondary work surface connecting means to define a second axis; a connecting plate; attached adjacent one of the parallel arms to the primary and secondary work surface connecting means; having a first pivot point rotatable about the first axis and a second pivot point being rotatable about the second axis; such that when the arm is pivoted about the first axis, an angular position of the secondary work surface with respect to the primary work surface is substantially constant. 
   The brake system is advantageously operated using a remote control mechanism, which advantageously is arranged inside the hollow arm. 
   The remote control mechanism has a movement transmitting means, which advantageously is arranged inside the hollow arm. 
   Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Embodiments of the present invention will now be described, by way of example only, with reference to the attached Figures, wherein: 
       FIG. 1  is a perspective view of an adjustable work surface support in accordance with an embodiment of the present invention; 
       FIG. 2  is another perspective view of the adjustable work surface support of  FIG. 1 ; 
       FIG. 3  is an exploded view from below of the work surface support mechanism; 
       FIG. 4  is a detailed perspective view of part of the work surface support with a secondary work surface in a lowered position; 
       FIG. 5  is a front view of the work surface support with the secondary work surface in a raised position; 
       FIG. 6  is a bottom view of the work surface support; 
       FIG. 7  is a side view of the works surface support with the secondary work surface in the lowered and tilted position; 
       FIG. 8  is a side view of the work surface support with the secondary work surface in the raised position; 
       FIG. 9  is a side view of the work surface support with the secondary work surface in a level position; 
       FIG. 10  is a side view of the work surface support with the secondary work surface in the lowered position; and 
       FIG. 11  is a perspective view of the work surface support. 
   

   DETAILED DESCRIPTION 
   Generally, the invention is directed at an adjustable work surface support  10  , or mechanism, for mounting a secondary work surface  12  to a primary work surface  14 . The adjustable work surface support  10  allows for a vertical pivoting movement of the secondary work surface  12  relative to the primary work surface  14 . 
   The work surface support  10  comprises a primary work surface connecting means, seen in the present embodiment as a pair of mounting brackets  16  (seen as brackets  16   a  and  16   b ) which are used to attach the support  10  to the primary work surface  14 . A secondary work surface connecting means, seen as a second pair of mounting brackets  18  (seen as brackets  18   a  and  18   b ) attach the work surface support  10  to the secondary work surface  12 . The mounting brackets  16  and  18  are both attached to a parallelogram link support, which in the preferred embodiment is a tubular substantially U-shaped double arm support  20  with one arm  21   a  connected at each end to brackets  16   a  and  18   a  and the other arm  21   b  connected at each end to brackets  16   b  and  18   b.    
   The double arm support  20  comprises a support bar or cross-bar  26 , which is mounted at each end to one of the first mounting brackets  16   a  and  16   b  and the two substantially parallel arms  21  extending from the cross-bar  26 . The double arm support  20  is preferably constructed as a one-piece tubular construction, with the arms  21  formed integral with the cross-bar  26  in order to provide further support to the primary and secondary work surfaces  14  and  12  and to lower the number of parts required for the work surface support  10 . 
   The two arms  21  attach to the secondary work surface  12  via the pair of second mounting brackets  18   a  and  18   b . The cross-bar  26  defines a first axis about which the work surface support  10  rotates and while the attachment of the arms to the secondary work surface connecting means defines a second axis of rotation. 
   The shape of the arms  21  is preferably U-shaped with edge sections  22  of each arm  21  at an angle from a bottom section  24  in the preferred embodiment. The angles at which the edge sections  22  are angled from the bottom section  24  are selected to provide clearance under the work surfaces full sweep (or range of motion) of the secondary work surface. Adjacent and parallel to one of the arms  21   a  is a connecting plate  25  which is used to maintain the parallelism between the two work surfaces  12  and  14  when the secondary work surface  12  is in the default position (not tilted). 
   The double arm support  20  provides the mechanism for the secondary work surface  12  to move relative to the primary work surface  14  as will be described below. 
   The work surface support  10  also comprises a brake mechanism  30  which allows a user to release and lock the position of the secondary work surface  12 . The brake mechanism comprises a brake attachment mechanism  32  and is mounted to the primary work surface  14  via a brake mechanism mounting means, seen as a mounting bracket in the Figures. In the preferred embodiment, the brake mechanism is a gas cylinder actuated cable system. 
   When the brake mechanism is disengaged or released, the work surface support  10  is allowed to rotate about the first axis defined by the cross-bar  26 . When engaged or locked, the brake mechanism  30  securely holds the cross-bar  26  and the arms  21  in a locked position relative to the primary work surface  16  via a first brake mechanism attachment  32  arranged on the cross-bar  26 . The brake mechanism  30  is preferably actuated via a remote control mechanism  36  which is attached to the secondary work surface  12 , so that a user can easily engage and disengage the brake mechanism  30  to adjust the vertical position of the secondary work surface  12  (via the support  20 ) relative to the primary work surface  14  from a level position (where the surface of the secondary work surface  12  is in the same plane as the surface of the primary work surface  14 ) to a lowered position (where the surface of the secondary work surface  12  is lower than the surface of the primary work surface  14 ) or a raised position (where the surface of the secondary work surface  12  is above surface of the primary work surface  14 ) as the need of the user dictates. It will be understood that there are numerous raised and lowered positions since the position of the secondary work surface  12  with respect to the primary work surface  14  is defined by the user. In the present embodiment, the remote control mechanism  36  is a pedal connected to the brake mechanism  30  via a cable  38 , or other movement transmitting means. The cable  30  is preferably located within one of the arms  21  so that it does not interfere with any objects underneath the work surfaces, to avoid entanglement and possible injury to the user&#39;s legs and to protect the cable  38  from being damaged. 
   As discussed above, the secondary work surface connecting means, or the second pair of mounting brackets  18   a  and  18   b , defines a second axis about which the double arm support  20  rotates so that the secondary work surface  12  may move to any position desired by the user. A tilting mechanism  40  holds the secondary work surface  12  in a desired tilted position when the tilting mechanism  40  is in its locked position and permits a pivoting movement of the secondary work surface when the tilting mechanism  40  is in a released position thereby allowing the angle of the surface of the secondary work surface  12  to be changed. The tilting mechanism  40  is preferably a friction-friction lock, however, other types of locks such as a spin knob lock, friction brake mechanisms and ratchet mechanisms are contemplated. 
   Turning to  FIG. 2 , a second perspective view of the work surface support  10  is shown. 
   Although shown in  FIGS. 1 and 2  as a single bracket  16   a , it will be understood by one skilled in the art that the mounting bracket  16   a  may be of two-piece construction. The one-piece construction of the bracket in the preferred embodiment provides more load bearing capabilities for the primary work surface  10  than a two-piece bracket. A fastening plate  15  is located at one end of the bracket  16   a  to hold it in place against the primary work surface  14 . 
   Turning to  FIG. 3 , an exploded view of the work surface support  10  is shown. 
   Turning to  FIG. 4 , a perspective view of part of the work surface support in the lowered position is shown. 
   As can be seen in  FIG. 4 , the secondary work surface  12  is in a position lower than the primary work surface  14  (the lowered position), however, the secondary work surface  12  remains parallel to the primary work surface  14  due to the connecting plate  25   
     FIG. 5  provides a front view (from a user&#39;s perspective) of the work surface support  10  with the secondary work surface  12  in the raised position. As can be seen in the Figure, rotation of the support  20  about the first axis causes the tubular arms  21  to rotate about the first axis and moving the secondary work surface  12  with respect to the primary work surface  14 . 
   The presence of tubular arms results in non-bending parts which means that user&#39;s fingers or legs will preferably not get caught during movement of the secondary work surface  12 . Furthermore, there is little space between the connecting plate  25  and the arm  21   b  in which a user&#39;s fingers may be inserted, possibly causing injury. 
   As can be seen, an end of the cable  37  from the brake mechanism  30  is connected to the remote control mechanism  36 . The depression/activation of the remote control mechanism causes the brake mechanism to release and therefore allow movement of the secondary work surface  12  with respect of the primary work surface  14 . 
   The general range for the position of the secondary work surface  12 , with respect to the primary work surface  14 , is approximately eight inches above and seven inches below, however, a larger range may be appreciated with the work surface support  10  of the present invention. 
     FIG. 6  is a bottom view of the work surface support which illustrates the parallel nature of the arms  21  of the double arm support  20 . In this Figure, the secondary work surface  12  is in the default position with respect to the primary work surface  14 . The mounting brackets  16  and  18  are preferably mounted to the primary and secondary work surfaces, respectively, via fasteners  50  such as screws. 
   In operation, the brake mechanism  30  is released allowing the cross-bar  26  to rotate about the first axis and the two arms  21  to move in unison to move the secondary work surface  12  to its desired position. 
   Turning to  FIG. 7 , a view of the secondary work surface  12  in the lowered position with the table top of the secondary work surface tilted is shown. 
   The secondary work surface  12  is tilted when the tilting mechanism  40  is released. This is preferably achieved via a bolt (not shown) in a third mounting bracket  62  which moves through a slot  54  in one of the second mounting brackets  18  when the tilting mechanism  40  is released. When the tilting mechanism is engaged or tightened, the table top of the secondary work surface  12  is locked into place. 
   The tilting mechanism  40  allows for the plane of the secondary work surface to be tilted towards the user so that they may have easier access to the secondary work surface  12 . In the example of a computer desk, it is easier for a user to type on the keyboard which is directed towards them rather than on a flat horizontal surface. The default position of the secondary work surface  12  is shown in dotted line while one tilted position of the secondary work surface is shown in solid line. The arrows  60  indicate the direction in which the secondary work surface  12  moves from the default to the tilted position shown. 
   As described before, the connecting plate  25  maintains the parallel relationship between the primary and secondary work surfaces  14  and  12 . The parallel nature of the two work surfaces is not defined by table top working surfaces but by the positions of the primary and secondary work surface connecting means  16  and  18  with respect to each other after the secondary work surface  12  has been moved. 
   Turning to  FIG. 8 , a side view of the work support surface  10  with the secondary work surface  12  in the raised position is shown. As once again shown, the connecting plate  25  maintains the parallel relationship between the first and second axis (the connecting means) of the two work surfaces  12  and  14 . As discussed above, the secondary work surface  12  moves relative to the primary work surface  14  after the brake mechanism  30  has been released or disengaged. In order to lock the secondary work surface  12  in place, the brake mechanism is then relocked or engaged. 
   Turning to  FIG. 9 , a side view of the secondary work surface  12  in the default position is shown while  FIG. 10  is a side view of the secondary work surface  12  in a lowered position. In each of  FIGS. 8 to 10 , a dashed square indicates the relative relationships between the support brackets  16  and  18  of the primary  14  and secondary  16  work surfaces respectively to indicate the parallel relationship which is maintained between the primary and secondary work surfaces when the secondary work surface is moved. In  FIGS. 8 and 10 , the dashed arc which runs through the secondary work surface  12  represents a preferred travel path for the secondary work surface  12  when it moves relative to the primary work surface  14 . 
   A further discussion is now provided regarding the parallelism provided by the connecting plate  25 . In order to maintain the secondary work surface  12  in parallel relative to the primary work surface  14  as has been set by the user, the parallelogram linkage system is utilized. The connecting plate  25  is arranged adjacent to one of the double arms  21 . The connecting plate  25  is pivotably attached at a first end to one of the first mounting brackets  16   b  and at a second end to the third mounting bracket  62 , which is sandwiched between the connecting plate  25  and the secondary mounting bracket  18   a . The arm  21   a  is mounted to the secondary mounting bracket  18   a  through the third mounting bracket  62 . The first axis, or pivot point  64  of the primary work surface  16 , the second axis, or pivot point  66  the secondary work surface  14  and the connecting plate  25  form a parallelogram, which allows the cross-bar and the arms  21  to move through their respective axes of rotation while holding the secondary work surface  12  at a constant relative to the primary work surface  14 . When the arm  21   a  is rotated about the first axis, the connecting plate  25  translates with the arm  21   a  and rotates around its two pivot points. The connecting plate  25  is preferably of a similar shape as the arms of the double arm support so the connecting plate  25  does not impede with the movement of the arms  21  through the first axis of rotation of the support. 
     FIG. 11  is a schematic diagram of the work surface support without the primary and secondary work surfaces. This simply provides a clearly view of an embodiment of the present invention. 
   Other brake mechanisms which are contemplated include spring brakes or gas cylinder brakes, especially counterbalanced brake arrangements. The counterbalancing feature constrains the downwards motion of the arm, and thus of the attached secondary work surface, when the brake mechanism is released. 
   An advantage of the present invention is that by having tubular arms, the presence of pinch points (locations where user&#39;s fingers may be caught or pinched between parts) is reduced/removed. Therefore, there is little opportunity that a user&#39;s fingers could get caught between the arm  21   a  and the plate  25 . This allows the preferred embodiment of the work surface support to be used by youth as well as adults. 
   In another advantage of the present invention, the range of motion between the lowest position and the highest position of the secondary work surface with respect to the primary work surface is not restricted. By extending the length of the arms, a wider range may be appreciated. 
   The above-described embodiments of the invention are intended as examples only. Alterations, modifications and variations may be effected to the particular embodiments by those of skill in the art without departing from the scope of the invention, which is defined solely by the claims appended hereto.