Abstract:
An ergonomic work station for computer components or for other purposes that is especially adapted for use by an individual having decreased mobility due to back pain or other conditions. The work station includes a base that extends beneath a chair or bed. A support arm has counter weight on a first side of a pivotal mount and a work table on a second side of the pivotal mount. The support arm may be pivoted to place the table in a work position in front of a user or in vertical position to permit unobstructed egress from or ingress to the chair or bed. The counter weight allows for the support arm to be easily pivoted from the work position to the vertical position by application of only very light pressure.

Description:
FIELD OF THE INVENTION 
   This invention relates generally to an ergonomic work station. More particularly, the invention relates to a work station specially adapted for ease of use by an individual bothered by back pain. 
   BACKGROUND OF THE INVENTION 
   Many occupations require a worker to spend long periods of time in front of a computer screen. Problems associated with repetitive motion injuries due to computer keyboard or mouse manipulation may result in injuries to a computer user. A well known injury associated with repetitive motion is carpal tunnel syndrome. Injuries and discomfort may be minimized by proper positioning of a user with respect to a work object. Ergonomic designs for chairs and work stations have attempted to address these problems. 
   For an individual who experiences back pain, however, the simple act of sitting upright for long periods of time may result in debilitating discomfort. Further, the simple act of entering or exiting from a typical computer work station requires that a user bend his or her body in ways that may be uncomfortable or impossible for an individual experiencing back pain. 
   Some inventors have attempted to address the needs of individuals who, for whatever reason, are unable to sit in front of a computer. For example, U.S. Pat. No. 4,848,710 to Newman teaches a “Support Device” wherein a personal computer may be used by a person lying on a bed. The support body can be mounted on the bed itself, or on a base running on wheels beneath the bed. 
   Another example is U.S. Pat. No. 5,630,566 to Case for a “Portable Ergonomic Work Station”. Case teaches a portable workstation that includes a variety of adjustable support elements that may hold and support computer components. 
   U.S. Pat. No. 6,286,794 to Harbin for an “Ergonomic Computer Mounting Device Permitting Extensive Vertical, Horizontal and Angular Ranges of Motion” teaches a column having a tilt and swivel mechanism for mounting a computer monitor thereon. The tilt and swivel mechanism is slidably mounted in a vertical track and a counterweight is provided to assist in vertical adjustment. 
   Other inventors have attempted to design systems for use with a chair or recliner. For example, U.S. Pat. Nos. 4,880,270 and 5,056,864 to Cooper for a “Work Station System” includes a chair having a carriage secured thereto. A surface for supporting an input device and a keyboard are attached to the carriage. The chair is rockable about a horizontal axis, but the spatial distance between the surface for supporting an input device and the seated operator remain constant, as does the spatial distance between the surface for supporting the visual display and the seated operator. 
   U.S. Pat. No. 5,779,305 to Hocking teaches “Work Stations” having a chair and a means to support pieces of equipment such as a personal computer, a printer and the like. The station has at least two upright stanchions that project upwardly in a substantially parallel manner from a base. Sleeves are engaged on the stanchions. Support members for the pieces of equipment are attached individually or in combination to a sleeve or sleeves so the support members will extend from the sleeves in a direction substantially normal to the longitudinal axis of the stanchions. 
   U.S. Pat. No. 5,967,599 to Cauffiel for a “Cabinet and Table Assembly for Use with Seating Apparatus” teaches a table that can slide between extended and retracted positions relative to a chair and may also be horizontally pivoted between a working position and an out-of-the-way position. 
   U.S. Pat. No. 6,102,476 to May et al. for a “Computer Furniture with Integrated Computer” teaches a chair with a monitor support and a keyboard support mounted on a horizontal arm that is pivotally attached to the left armrest. 
   U.S. Pat. No. 6,425,631 to Lin teaches a “Computer Chair Assembly” having a chair with two armrests, wherein a pivot shaft is disposed on one of the armrests. A horizontal rod is supported on one end by the pivot shaft and on a second end by rollers and a support. The horizontal rod supports an article support frame that may be pivoted in front of or away from a user seated in the chair. 
   None of the above references are ideal for use by an individual experiencing severe back pain. For example, none of the references teach a vertically pivoting member that permits a user to easily access a bed or chair wherein the pivoting member may be manipulated with fingertip pressure due to counter-weighting of the pivoting member. Additionally, it is desirable for a work station system to provide the above benefits in combination with structure that is adjustable in multiple ways to locate work pieces in an ergonomic orientation with respect to a user. 
   SUMMARY OF THE INVENTION 
   According to the present invention there is provided an improvement in an ergonomic computer workstation. The work station of the invention includes a base that extends beneath a human support device such as a chair, bed, or other structure. The base is preferably adjustable in length to accommodate human support devices of different widths. A riser extends upwardly from the base. A support arm pivotally connects to the riser and is stabilized by a support affixed to the riser and/or a support located at a distal end of the support arm. Preferably, both the riser and the supports are adjustable with respect to height for positioning a table at a desired height in front of a user. The support arm has a first section on a first side of the riser and a second section on a second side of the riser. The table is affixed to the second section of the support arm. 
   By pivoting the support arm, the table may be placed in a work position in front of a user or in a second position that removes the support arm and table as an encumbrance to egress from or ingress to the human support device. Preferably, the second position of the support arm is substantially vertical. A counter weight is affixed to the first section of the support arm. The counter weight allows for the support arm to be easily pivoted from the work position to the second position by application of only finger pressure. The table defines a plurality of retaining members for affixing selected computer components or other devices to the table, such that the devices do not move or fall off when the support arm and table are pivoted from a horizontal orientation to a non-horizontal or vertical orientation. 
   A better understanding of the present invention, its several aspects, and its advantages will become apparent to those skilled in the art from the following detailed description, taken in conjunction with the attached drawings, wherein there is shown and described the preferred embodiment of the invention, simply by way of illustration of the best mode contemplated for carrying out the invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  shows a perspective view of a work station of the invention. 
       FIG. 2  shows an elevation view of the work station of the invention wherein the pivot member and table assembly is shown in a raised and partially raised position in phantom lines. 
       FIG. 3  is a side elevation view of the work station of  FIG. 1  wherein a computer monitor is shown positioned on the table in phantom lines. 
       FIG. 4  is a side elevation view of the work station of  FIG. 1  wherein the table is shown in several positions with phantom lines. 
       FIG. 5  is a side elevational view of a work station of the invention shown positioned adjacent a chair and showing a position of a user. 
       FIG. 6  is a front elevational view of a work station of another embodiment of the work station of the invention. 
       FIG. 7  is an enlarged perspective view of a pivot arm support of  FIG. 6 . 
       FIG. 8   a  is a cross-sectional view taken along line  8 — 8  of  FIG. 7 . 
       FIG. 8   b  is a cross-sectional view taken along line  8 — 8  of  FIG. 7 . 
       FIG. 9   a  is a cross-sectional view taken along line  9 — 9  of  FIG. 7 . 
       FIG. 9   b  is a cross-sectional view taken along line  9 — 9  of  FIG. 7 . 
       FIG. 10  is a partial cross-sectional view showing a riser of a workstation of the invention, taken along lines  10 — 10  of  FIG. 2  and showing an enclosed pneumatic lift cylinder. 
       FIG. 11  is a cross-sectional view of the pneumatic lift cylinder of  FIG. 10 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Before explaining the present invention in detail, it is important to understand that the invention is not limited in its application to the details of the embodiments and steps described herein. The invention is capable of other embodiments and of being practiced or carried out in a variety of ways. It is to be understood that the phraseology and terminology employed herein is for the purpose of description and not of limitation. 
   Referring now to  FIGS. 1–6 , shown is a work station  10 . Work station  10  has a base  12 . Base  12  has a first stabilizing member  14  and a cross member  16 . Cross member  16  is preferably adjustable in length to accommodate different sizes of chairs, beds or other human support devices. Cross member  16  may span between components of work station  10  ( FIG. 1 ), or cross-member  16  may adjustably extend from a single set of components ( FIG. 6 ). A first extension member  18  extends from the first stabilizing member  14 . A second extension member  20  also extends from first stabilizing member  14 . Base  12  may additionally include a second stabilizing member  22 . 
   A first riser  24  extends vertically from first stabilizing member  14 . First riser has a first sleeve member  26  telescopically received on a first vertical base piece  28 . First sleeve member  26  defines a plurality of orifices  30  for affixing the first sleeve member  26  at a desired height, by means of a guide pin  31  ( FIG. 10 ), securing devices  33  ( FIGS. 3 &amp; 10 ), both, or other securing devices. 
   A second riser  32  extends vertically from first stabilizing member  14 . Second riser  32  has a second sleeve member  34  telescopically received on second vertical base piece  36 . Second sleeve member  34  defines a plurality of orifices  38  for affixing second sleeve member  34  at a desired height by means of a guide pin  39  ( FIG. 10 ), securing devices  33  ( FIGS. 3 &amp; 10 ), both, or other securing devices. 
   Referring back to  FIG. 1 , a first brace member  40  is affixed to first extension member  18  and first vertical base piece  28  for stabilizing first riser  24 . A second brace member  42  is affixed to second extension member  20  and second vertical base piece  36  for stabilizing second riser  32 . In an alternate embodiment, first brace member  40  and second brace member  42  are replaced with a plurality of tension members  44  ( FIGS. 5 &amp; 6 ). Preferably, tension members  44 , which may be metallic cables, bicycle spoke-type rods or other members, extend between first stabilizing member  14  and first vertical base piece  28 , first stabilizing member  14  and second vertical base piece  36 , first extension member  18  and first vertical base piece  28 , second extension member  20  and second vertical base piece  32 , cross member  16  and first vertical base piece  28 , and cross member  16  and second vertical base piece  36 . 
   A cross-support  46  spans between first riser  24  and second riser  32 . A pivot member  48  also spans between first riser  24  and second riser  32 . A support arm  50  is pivotally affixed to pivot member  48 . Support arm  50  has a first section  52  that terminates in a first end  54  on first side of risers  24  and  32 . Support arm  50  has a second section  56  terminating in a second end  58  on the second side of risers  24  and  32 . Preferably, cross-support  46  has a recessed portion for receiving first section  52  of support arm  50  when support arm  50  is in an upright position. A support arm cradle  60  is affixed to first sleeve member  26  and second sleeve member  34  of first riser  24  and second riser  32 . First pivot member cradle  60  is provided to maintain support arm  50  in a horizontal or work position. 
   In another embodiment, shown in  FIGS. 6–9   d , a support arm sleeve  62  is provided that has a first inverted segment  64  for contacting first section  52  of pivot arm  50 . First inverted segment  64  may be provided with a securing device for maintaining support arm  50  in contact with first inverted segment  64 , i.e., in a horizontal or working position. Examples of securing devices include a protuberance and mating orifice  65  ( FIG. 8   a ) and magnet  66  ( FIG. 8   b ) for attracting support arm  50 . Support arm sleeve  62  is additionally provided with a second segment  67  for contacting second section  56  of support arm  50 . Second segment  67  may also be provided with a securing device for maintaining support arm  50  in contact with second segment  67 , i.e., maintaining support arm  50  in a horizontal or working position. Examples of securing devices include a protuberance and mating orifice  65  ( FIG. 9   a ) and magnet  69  ( FIG. 9   b ) for attracting support arm  50 . As shown in  FIGS. 6  and  7 , tension members  68  may be provided from the support arm sleeve  62  to first and second sleeve members  26 ,  34  of risers  24 ,  32 . 
   Referring back to  FIG. 1 , a first shelf  70  is preferably provided. First shelf  70  may be used to support a computer CPU and/or a printer or other device. First shelf  70  has a free pair of shelf supports  72  and an attached pair of shelf supports  74 . Attached pair of shelf supports  74  are preferably affixed to the first stabilizing member  14 . Shelf  70  and supports  72  and  74  can be mounted on either end of first stabilizing member  14 . 
   A second shelf  76  is preferably also provided. Second shelf  76  may be used as a work stand to hold a computer CPU/printer, papers or other materials. Second shelf  76  preferably has a free shelf support  78  and a pair of attached shelf supports  80 . Attached shelf supports  80  are preferably affixed to second stabilizing member  22 . Second shelf  76  is additionally supported by cradle stand  82 . Shelf  70  can be reversed on shelf supports  80  and  82  with free shelf support  78  attaching to shelf  70  on the opposite side of cross member  16  and second stabilizing member  22 . By permitting first shelf  70  and second shelf  76  to be located on either side of cross member  16 , a user has greater flexibility to set-up the workstation in a desired configuration. 
   Still referring to  FIG. 1 , cradle stand  82  extends vertically from cross member  16  proximate said second stabilizing member  22 . Cradle stand  82  has an arm receiving member  84  on an upper end thereof. Arm receiving member  84  is provided for receiving second end  58  of support arm  50 . Cradle stand  82  is preferably adjustable to allow for setting support arm  50  at a desired height, which preferably corresponds to height adjustments of risers  24  and  32 . 
   A pivotal counter weight receiving member  100  is pivotally affixed to first end  54  of support arm  50 . A selected amount of weight  102  may be affixed to counter weight receiving member  100  for counterbalancing support arm  50 . By selecting an appropriate amount of weight  102  a perfect balance of support arm  50  may be achieved about pivot member  48  for fingertip positioning of support arm  50  whether support arm  50  is unloaded or fully loaded. 
   A table  104  is rotationally affixed to second section  56  of support arm  50 . Table  104  is preferably secured to support arm  50  by a plurality of hinge members  106 . Table  104  preferably defines a plurality of retaining members  108 . Examples of retaining members  108  include grooves for receiving threaded securement devices, protuberances for engaging an item, receptacles for receiving protuberances from an item, slots for receiving protuberances from an item, hooks for grasping an item, or other suitable retaining features. Examples of items that may be retained on table  104  include keyboard or laptop computer  109   a  ( FIG. 2 ), mouse  109   b  ( FIG. 2 ), and monitor  109   c  ( FIGS. 2–5 ). Table  104  preferably has a work area  110  on a first side of support arm  50  and a monitor area  112  on a second side of support arm  50 . Locking members  114  are preferably provided on selected hinge members  106  for securing table  104  in a desired rotational orientation with respect to support arm  50 . Locking members may be worm gears that function to set table  104  at a desired orientation. 
   A human support device  120  ( FIGS. 5 and 6 ) is positioned over cross member  16  such that a human is supported by human support device  120  in a position suitable for easily accessing computer components that may be affixed to table  104 . Preferably, support arm  50  is adjusted at an appropriate height and table  104  is rotationally positioned such that a user may support his or her elbows on human support device  120  and have easy access to laptop computer/keyboard  109   b  secured on table  104 . Additionally, work station  10  and/or human support device  120  is positioned such that the eyes of the user are positioned directly in front of monitor  109   c  in an ergonomically desirable orientation. 
   To assist in positioning work station  10 , a pneumatic cylinder  130  ( FIGS. 10 ,  11 ) may be located within one or both of risers  24  and  32 . Pneumatic cylinder  130  is preferably constructed of a base tube  132  and a sliding tube  134 . An air tight seal is formed between base tube  132  and sliding tube  134  with seal  136  ( FIG. 11 ). A metering orifice  137  is provided to equalize pressure between base tube  132  and sliding tube  134  to provide shock absorbing action within risers  24  and  32 . A top cap  138  seals the top of sliding tube  134  and a bottom cap  131  seals the bottom of the base tube  132 . A top filler  140  ( FIG. 10 ) preferably provides top cap  138  a flat area to apply lifting force equally within the conical neck between top cap  138  and pivot member  48  of risers  24  and  32 . A stem  142  preferably protrudes from sliding tube  132  for receiving air from a compressed air source (not shown). 
   In use, workstation  10  of the invention is preferably configured such that support arm  50  may be positioned in an upright orientation as shown in  FIG. 2  with phantom lines. When support arm  50  is set in an upright position, a user may easily access a human support device  120  such as a reclining chair shown in  FIG. 5  or a mattress shown in  FIG. 6 . Once a user has positioned himself or herself in a desired position on human support device  120 , a user may pivot the support arm  50  about pivot member  48  to easily position the table  104  in front of the user. To assist in manipulating support arm  50 , weights  102  are preferably mounted on counterweight receiving member  100  in an amount that perfectly balances the weight of table  104  and computer components affixed thereto, such as, laptop/keyboard  109   a , mouse  109   b , and monitor  109   c . The computer components are preferably removably affixed to the table  104  such that the components do not inadvertently move when the support arm  50  is positioned in the upright position. If an appropriate amount of weight  102  has been affixed to the counterweight retaining member  100  then only fingertip pressure is required to manipulate the support arm  50  from an upright position to a horizontal or work position. Therefore, the workstation  10  of the invention is ideally suited for use by individuals having physical limitations such as back injury or other limitations. 
   When support arm  50  is in a horizontal position, the support arm  50  and table  104  is supported by a first pivot member cradle  60  as shown in  FIG. 2 . Alternatively, pivot arm  50  may be supported by support arm sleeve  62  shown in  FIGS. 6 and 7 . Support arm sleeve  62  works in conjunction with first inverted segment  64  and second segment  67  each of which functions to maintain the support arm  50  in a stable horizontal configuration. Additionally, a cradle stand  82  with cradle member  84  may be provided to support second end  58  of pivot arm  50 . To ensure optimum positioning, the table  104  may be rotationally adjusted about support arm  50  via hinge members  106 . Locking members  114  are utilized to affix table  104  in a preferred rotational orientation with respect to support arm  50 . Ideally, computer monitor  109   c  is located in an ergonomic relationship with respect to the eyes of a user. For example, some people advocate that a monitor, such as monitor  109   c , should squarely address a user and that the monitor screen should be positioned approximately arms&#39; length away from and slightly below the forward field of vision of the user. Preferably, a user should be able to support his or her elbows on the human support device  120  and be able to access laptop computer/keyboard  109   a  on work area  110  of table  104 . 
   When a user desires to discontinue work on the work station  10 , the user may apply light pressure to a support arm  50  and pivot the table surface  104  upwards until support arm  50  is in a vertical or upright configuration. Counterweight member  100  is offset slightly from a longitudinal access of the support arm  50 . As a result, when the support arm  50  is in an upright configuration, the pivot arm is weight biased to maintain balance through the full range of travel, i.e., the offset of counterweight member  100  functions to counterbalance items  109   a ,  109   b  and  109   c , when support arm  50  is in a vertical orientation. Travel beyond an upright position is restricted by the cross support member  46  visible in  FIGS. 3 and 5 . 
   As a further assistance to a user in adjusting a height of the table  104 , one or more of risers  24  and  32  may be provided with a pneumatic cylinder  130  located therein. The pneumatic cylinder  130  functions to easily adjust the height of risers  24 ,  32 . Compressed air or other compressed fluid that may be provided by an electrical compressor or other means to drive pneumatic cylinder  130  to a desired position. 
   Depending upon the desired configuration, the workstation  10  may be comprised of components on a first side of human support device  120  and a second side of human support device  120  as shown in  FIG. 2 . Alternatively, it may be desirable to maintain or to locate components of workstation  10  on a single side of human support device  120  as shown in  FIG. 6 . 
   In summary, the work station of the invention provides an ergonomically positionable structure that allows for a user to easily access computer equipment such as a keyboard and monitor while in a substantially horizontal or reclined position. The work station of the device is therefor ideal for individuals who experience back pain and for whom maintaining a seated position for extended periods of time is painful or impossible. An additional advantage of the workstation of the invention is that when properly configured, weights located on counterweight receiving member counterbalance support arm  50  about pivot member  48  such that support arm  50  may be easily pivoted from a horizontal position to a vertical position. Ideally, support arm  50  may be moved with only fingertip pressure. The ability to move support arm  50  from a vertical to horizontal position with minimal effort is desirable for individuals who are plagued with back pain. A further advantage of the invention is that support arm  50  may be pivoted upwards to a vertical position. The vertical position allows completely open access to the human support device whether the human support device is a reclining chair, a bed or other type of support device. Therefore, a user benefits from unobstructed ingress to and egress from the human support device. 
   A further advantage of the invention is that the support arm  50  is maintained in a vertical position by offsetting weights  102  from vertical when the support arm  50  is in a vertical position. By displacing the weights  102  from the vertical axis of support arm  50 , the support arm  50  is maintained in a balanced state, even when support arm  50  is in a vertical orientation, thereby preventing inadvertent movement of support arm  50 . 
   While the invention has been described with a certain degree of particularity, it is understood that the invention is not limited to the embodiment(s) set for herein for purposes of exemplification, but is to be limited only by the scope of the attached claim or claims, including the full range of equivalency to which each element thereof is entitled.