Abstract:
A monitor lift mechanism that can be utilized in connection with a desk having a stationary work surface. The monitor lift mechanism is movable between a retracted position in which a monitor is positioned beneath the work surface, and an extended position in which the monitor is positioned above the work surface for viewing. The monitor lift mechanism includes a lift bar that is movable between a retracted position and an extended position through the use of a block and tackle pulley and lift cylinder arrangement. A latch mechanism holds the lift bar in the retracted position and can be released upon depression of a monitor door coupled to the lift bar.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present application relates to and claims priority from U.S. Provisional Patent Application Ser. No. 61/291,162, filed Dec. 30, 2009, which is fully incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The present disclosure generally relates to tables and/or computer work stations for use in instructional environments. More specifically, the present disclosure relates to a mechanism that allows a monitor to move between a concealed, storage position and an extended, viewing position when needed. 
     The dramatic increase in the usage of computers and computer monitors in classrooms, lecture halls and meeting rooms has necessitated multi-purpose rooms that can be converted from a computer-based classroom environment to a conventional lecture hall or laboratory requiring writing or drafting space. As an example, in some configurations, the room may require a flat work surface for text, written materials and conventional note taking along with an unobstructed view of the surrounding areas. In other configurations, the room may require the use of video monitors and keyboards for data entry into a computer coupled to the monitor. 
     In some cases, tables have been designed to incorporate a method of mechanically raising a monitor from beneath a table surface, such as taught by U.S. Pat. Nos. 4,735,467 and 6,609,465. However, each of these convertible tables requires a substantial mechanism to lift and lower the display. Such equipment requires regular maintenance, may be expensive, and may significantly impair a user&#39;s ability to see a presenter and substantial parts of the use area. 
     SUMMARY OF THE INVENTION 
     The present disclosure relates to a monitor lift mechanism that attaches to a desk. The design of the present disclosure allows a user to store and secure a monitor, keyboard and mouse below a work surface when not in use, and quickly and easily raise the monitor and peripherals to a position above the desk surface when needed. The monitor lift mechanism allows a room to be converted for multiple uses, such as in transforming a computer lab to a study or lecture hall that may not require a computer monitor. 
     The monitor lift mechanism includes a steel housing that acts as a storage compartment for a lift cylinder mounted to the work surface. A roller bracket weldment is mounted to the bottom surface of the work surface and includes four rollers that provide the guide and bearing surface for a steel lifting bar to which a monitor is attached. A block and tackle pulley arrangement attached to the housing and the lift bar provide the lifting power to move the monitor from a retracted, storage position to an extended, viewing position. Preferably, a latch mechanism keeps the lift bar and door in the stored position and can be released to allow the monitor to move to the extended position. A keyboard and mouse can be stored on a shelf or storage tray that moves along with the lift bar and monitor. Wire management for the various wires connecting the monitor, keyboard and mouse to a computer are handled neatly by a corrugated tube that prevents wire pinching. 
     During operation, the closed unit can be opened by pushing down slightly on the monitor door. The depression of the monitor door relative to the work surface releases the latch mechanism, and the door and monitor will rise automatically to the extended, viewing position as a result of the lift cylinder. The keyboard and mouse can then be removed from the storage tray for use. After use, the keyboard and mouse can be re-stowed and the door with the attached lift bar can be pushed down until the door is flush with the work surface, and the latch mechanism engages to hold the lift bar in its retracted, storage position. 
     Various other features, objects and advantages of the invention will be made apparent from the following description taken together with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawings illustrate the best mode presently contemplated of carrying out the disclosure. In the drawings: 
         FIG. 1  is a partial perspective view illustrating the monitor lift mechanism in a retracted, storage position and mounted beneath a work surface; 
         FIG. 2  is a perspective view of the monitor lift mechanism in an extended, viewing position; 
         FIG. 3  is an exploded, perspective view of the components of the monitor lift mechanism; 
         FIG. 4  is a perspective view of the monitor lift mechanism in the retracted position with the housing removed; 
         FIG. 5  is a sectional view taken on line  5 - 5  of  FIG. 1 ; 
         FIG. 6  is a sectional view taken on line  6 - 6  of  FIG. 5 ; 
         FIG. 7  is a back view of the monitor lift mechanism in the retracted position; 
         FIG. 8  is a perspective view of the monitor lift mechanism in the extended, viewing position; 
         FIG. 9  is a sectional view taken on line  9 - 9  of  FIG. 2 ; 
         FIG. 10  is a back view of the monitor lift mechanism in the extended position; 
         FIG. 11  is a sectional view taken on line  11 - 11  of  FIG. 10 ; 
         FIG. 12  is a perspective view of the latch mechanism that holds the monitor lift mechanism in the retracted, storage position; and 
         FIGS. 12   a - 12   f  are diagrams of the sequential operation of the latch mechanism of  FIG. 12  during operation of the monitor lift mechanism. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  illustrates a monitor lift mechanism  10  mounted beneath a work surface  12 . In the embodiment shown in  FIG. 1 , the monitor lift mechanism  10  is in a retracted, storage position such that a monitor door  14  is received in a cutout  15  and is generally coplanar with the work surface  12  such that the monitor door  14  and work surface  12  create a unitary work surface. As can be seen in  FIG. 1 , the monitor lift mechanism  10  includes a metallic housing  16  that is mounted to a lower surface  18  of the work surface  12 . The housing  16  is spaced from the front edge  20  such that the knees and legs of a student can extend below the work surface  12 , as is conventional. 
       FIG. 2  illustrates the monitor lift mechanism  10  in an extended, viewing condition. In the extended position shown in  FIG. 2 , the monitor door  14  extends above the work surface  12  and is supported by a lift bar  22 . In the embodiment of  FIG. 2 , a video monitor  24  is shown in broken lines and mounted to the lift bar  22 . Thus, as the monitor lift mechanism  10  moves to the extended position of  FIG. 2 , the monitor  24  moves out of the housing  16  to the extended, viewing position shown in  FIG. 2 . Preferably, the lift bar  22  includes a series of mounting holes  26  that allow the monitor  24  to be securely attached to the lift bar  22 . 
     When the monitor lift mechanism  10  moves to the extended position of  FIG. 2 , a keyboard tray  28  moves upward and allows the operator to remove a keyboard (not shown). 
       FIG. 3  is an exploded, perspective view of the monitor lift mechanism  10 . As previously described, the lift mechanism  10  includes a housing  16  that mounts to the bottom surface of the work surface  12  by a series of attachment flanges  30 . The housing  16  includes a face plate  32  that mounts to the three-sided shell  34  through a series of connectors. The combination of the face plate  32  and shell  34  completely enclose the operating mechanism, as will be described. 
     The monitor door  14  is securely attached to a mounting plate  36  formed as part of the lift bar  22 . Keyboard tray  28  is also mounted to the lift bar  22  through a series of connectors  38 . In this manner, both the keyboard tray  28  and the mounting door  14  move along with the movement of the lift bar  22 . The monitor lift mechanism  10  includes a lift cylinder  40 , such as a pneumatic or hydraulic cylinder, mounted to the underside of work surface  12 , and having an extendable cylinder rod  42 . The lower end  44  of the cylinder rod  42  receives a pulley  46 . 
     As will be described in detail below, a lift cable  48  has a first end  50  attached to a fixed bolt  52  and a second end  54  attached to the bottom end  56  of the lift bar  22 . An intermediate pulley  58  is securely attached to a roller bracket weldment  60 . It can be appreciated that the cylinder rod  42  is engageable with the pulley and cable arrangement  46 ,  48 ,  58  extending between the work surface  12  and the lift bar  22 . The roller bracket weldment  60  in turn is securely attached to the bottom surface of the work surface  12  as well as to a back wall of shell  34  as seen in  FIGS. 5 and 6  to guide the movement of the lift bar  22 . 
     A latch mechanism  62  engages a pin  63  ( FIGS. 5 and 6 ) extending through and attached to the lift bar  22  and holds the monitor lift mechanism  10  in the retracted position until the latching mechanism  62  is released as will be described below. A pair of monitor balancing weights  64  are attached to the keyboard tray  28  to provide balancing of the monitor weight and to facilitate movement of the lift bar  22 . 
     The monitor lift mechanism  10  includes a wire management hose  66  that is corrugated over the entire length between the opposite ends  68 . The corrugated construction of the hose  66  allows the hose  66  to extend and contract upon movement of the lift bar  22 , as will be described. 
     The latch mechanism  62  is slidably mounted directly to a front face  69  ( FIG. 3 ) of the roller bracket weldment  60 . As seen in  FIGS. 6 and 7 , projections  62   a  are provided on a backside of latching mechanism  62  and are mounted in horizontally extending slots  69   a ,  69   b  formed in front face  69  to enable sliding movement of latch mechanism  62  back and forth on fixed weldment  60 . The latch mechanism  62  is movably mounted directly between the weldment  60  and the lift bar  22 , as seen in  FIG. 6 . 
       FIGS. 4-7  illustrate the monitor lift mechanism  10  in the retracted, storage condition. In the retracted, storage condition, the monitor  24  is contained and stored within the housing  16  below the work surface  12 , as illustrated in  FIG. 1 . 
     Referring back to  FIG. 7 , in the retracted condition, the lift cylinder rod  42  is in its fully retracted condition within the lift cylinder  40 . In this position, the second end  54  of the lift cable  48  is securely attached to the bolt  52  mounted to the undersurface of the work surface  12  along with the roller bracket weldment  60 . The first end  50  of the lift cable  48  is attached to a bracket  70  formed on the bottom end  56  of the lift bar  22 . As previously described, the lift cable  48  extends around an intermediate pulley  58  which is mounted to the roller bracket weldment  60 . Since the roller bracket weldment  60  is mounted to the underside of the work surface  12  and the shell  34 , the roller bracket weldment  60  is stationary. 
     Referring now to  FIG. 5 , the roller bracket weldment  60  includes a pair of upper rollers  72  and lower rollers  74 . The upper and lower rollers  72 ,  74  engage the side edge  76  of the lift bar  22  to guide the lift bar  22  during movement between its extended and retracted positions. 
     When the monitor lift mechanism  10  is in the retracted position of  FIGS. 4-7 , the latch mechanism  62  ( FIG. 12 ) engages the pin  63  attached to the lift bar  22  to prevent the lift bar  22  and attached monitor door  14  from moving from the retracted position to the extended position. The latch mechanism  62  includes a latch housing  77  which is movably mounted directly on the weldment and provided with a channel  78  having a notch  80  that receives the pin  63 . The shape of the channel  78  guides the pin  63  into different positions with various engagement surfaces of the latch mechanism  62  shown in  FIGS. 12 and 12   a - 12   f  during movement between the retracted and extended positions. To release the latch mechanism  62 , an operator depresses the monitor door  14  ( FIG. 12   b ), which moves the pin  63  out of notch  80  downward against a sloped wall  82  moving latch mechanism  62  along the slots  69   a ,  69   b  in the direction of arrow A thereby releasing the pin  63  and allowing the rod  42  of lift cylinder  40  to extend. 
     As the rod  42  of lift cylinder  40  extends, the pin  63  travels along the channel  78  to the position shown in  FIG. 12   c  in which the lift bar  22  and the door  14  can be moved upwardly by lift cylinder  40  to the fully extended position. During this motion, the housing  77  of latch mechanism  62  shifts back to a central position along slots  69   a ,  69   b  as shown in  FIG. 12   a . When it is desired to return to the retracted position, the monitor door  14  is pushed down to return the pin  63  to the position of  FIG. 12   c  and further move the pin  63  downwardly along a ramped surface  84  as shown in  FIG. 12   d . As this occurs, the housing  77  of latch mechanism  62  shifts along slots  69   a ,  68   b  in the direction of arrow B. Pin  63  continues to travel in channel  78  along a sloped wall  86  and engages a curved wall  88  as illustrated in  FIG. 12   e . At this point, releasing the downward push on monitor door  14  causes cylinder  40  to move pin  63  and lift bar  22  upwardly as seen in  FIG. 12   f  so that the pin  63  resets in notch  80  in the  FIG. 12   a  fully retracted position. During the motion represented in  FIGS. 12   e - 12   f , the housing  77  of latch mechanism  62  shifts along slots  69   a ,  69   b  in the direction of arrow C. It should be appreciated that the channel  78  and the engagement surfaces  80 ,  82 ,  84 ,  86 ,  88  define a continuous, non-circular path of travel for the pin  63  during movement of the lift bar  22  between the retracted and extended positions. It should also be understood that the channel  78  and engagement surfaces  80 ,  82 ,  84 ,  86 ,  88  collectively form a latch member fixed to the latch housing  77  for guiding and engaging the pin  63  between the retracted and extended positions. 
       FIGS. 8-10  illustrate the monitor lift mechanism  10  in the fully extended viewing position. In the fully extended, viewing position, the lift bar  22  moves relative to the stationary roller bracket weldment  60 . During this movement, the monitor door  14  and the keyboard tray  28  move upward to the position shown in  FIG. 2 . As can be understood in  FIG. 2 , the monitor  24  is positioned above the work surface  12  when the monitor lift mechanism  10  moves to the fully extended position. 
     Referring now to  FIG. 9 , after the pin  63  is released from latching mechanism  62 , the lift cylinder  40  operates to extend the lift cylinder rod  42 . As the rod  42  extends, the pulley  46  moves along the length of the lift cable  48 . Since the second end  54  and the first end  50  of the lift cable  48  are fixed, the extension of the lift cylinder rod  42  causes the lift bar  22  to move upward relative to the fixed roller bracket weldment  60 . During this upward movement, the upper and lower rollers  72 ,  74  engage the side edges  76  of the lift bar  22  and guide the movement of the lift bar  22 . As previously described, both the monitor door  14  and the keyboard tray  28  are attached to the lift bar  22  along with the monitor  24 . Thus, during movement of the lift bar  22 , the keyboard tray  28  moves upward to present the keyboard to a user. 
     Once a user has completed use of the monitor  24  and keyboard, the keyboard can be placed on the keyboard tray  28 , and the mounting door  14  can be pushed downward ( FIG. 12   d ) toward the retracted position. As the lift bar  22  moves downward, the latching mechanism  62  re-engages the pin  63  of lift bar  22  to hold the lift bar  22  and monitor  24  in the retracted position of  FIG. 1 . 
     Referring back to  FIG. 7 , the monitor balance weights  64  are mounted to the keyboard tray  28  to provide counterbalance for the weight of the monitor  24  when the monitor  24  is attached to the lift bar  22 . In this manner, the lift cylinder  40  can move the attached monitor  24  without having to exert an extreme amount of force. 
     While the invention has been described with reference to a preferred embodiment, those skilled in the art will appreciate that certain substitutions, alterations and omissions may be made without departing from the spirit thereof. Accordingly, the foregoing description is meant to be exemplary only and should not be deemed limitative on the scope of the invention set forth with the following claims.