Abstract:
A height adjustable table is disclosed wherein all horizontal supports that span between legs have been eliminated to increase storage space and knee space in the area under the table work surface. A unique telescoping leg arrangement is disclosed.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a continuation of U.S. patent application Ser. No. 13/053,942, filed Mar. 22, 2011 (issued as U.S. Pat. No. 8,256,359 on 4 Sep. 2012), which is a continuation of U.S. patent application Ser. No. 11/669,672, filed Jan. 31, 2007 (issued as U.S. Pat. No. 7,908,981 on Mar. 22, 2011), each of which is incorporated herein by reference and priority of each is claimed. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable 
     REFERENCE TO A “MICROFICHE APPENDIX” 
     Not applicable 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to height adjustable tables. More particularly, the present invention relates to an improved height adjustable table that includes specially configured telescoping legs that enable the table to be supported without the use of any obstructive supports that are typically placed in an intermediate position between a supported table top and a floor or other underlying support surface. Further, the present invention provides an improved telescoping leg arrangement that enables manual and/or motorized operation of the telescoping legs. 
     2. General Background of the Invention 
     Height adjustable tables enable different users to comfortably use the table notwithstanding differences in height. Additionally, height adjustable tables enable a user to vary the elevation of the table depending upon the activity being conducted. For example, a user might choose a first elevation of a table top when operating a computer. That person might set the table at a different height or elevation when reading a book. 
     Some height adjustables have been patented. The following table lists patents that have issued and that relate to height adjustable tables. 
     
       
         
               
               
               
             
           
               
                 TABLE 
               
               
                   
               
               
                 Pat. No. 
                 TITLE 
                 ISSUE DATE 
               
               
                   
               
             
             
               
                 4,515,087 
                 Height Adjustable Table 
                 May 7, 1985 
               
               
                 4,570,547 
                 Table With Adjustable Height Mechanism 
                 Feb. 18, 1986 
               
               
                 4,714,028 
                 Height Adjustable Table 
                 Dec. 22, 1987 
               
               
                 5,495,811 
                 Height Adjustable Table 
                 Mar. 05, 1996 
               
               
                 5,562,052 
                 Height Adjustable Table 
                 Oct. 08, 1996 
               
               
                 6,435,112 
                 Height Adjustable Table 
                 Aug. 20, 2002 
               
               
                 6,510,803 
                 Height Adjustable Table 
                 Jan. 28, 2003 
               
               
                 6,546,880 
                 Height Adjustable Table 
                 Apr. 15, 2003 
               
               
                 6,550,728 
                 Height Adjustable Table 
                 Apr. 22, 2003 
               
               
                 6,598,841 
                 Height Adjustable Table Leg 
                 Jul. 29, 2003 
               
               
                 6,935,250 
                 Adjustable Height Table With Multiple  
                 Aug. 30, 2005 
               
               
                   
                 Legs Operable By a Single Crank 
                   
               
               
                 7,077,068 
                 Height Adjustable Table 
                 Jul. 18, 2006 
               
               
                 8,256,359 
                 Height Adjustable Table 
                 Sep. 4, 2012 
               
               
                   
               
             
          
         
       
     
     The problem with most height adjustable tables is that they employ a horizontally extending beam or brace that spans between table legs at an intermediate position in between the table top and an underlying support surface (e.g. floor). This intermediate support prevents storage of large items (e.g. computers) under the desk. It also limits space available for a user&#39;s knees. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention provides an improved height adjustable table that eliminates the need for bracing at an intermediate position that is generally in between the table top of the height adjustable table and an underlying support surface such as the present invention provides an elevating table apparatus that includes a table top that provides an upper work surface and a lower surface. 
     A plurality of table legs include at least one pair of telescoping members including an inner member and a first outer sleeve member that has a bore that is receptive of the inner member. 
     The second outer sleeve member envelops the lower end of at least one of the table legs. 
     There are no connections that span in a generally horizontal direction or in a diagonal direction from one leg to another at a position below the table top. 
     The second outer sleeve does not prevent telescoping movement of the table legs. The second outer sleeve is a static member that remains at a lowermost position on the table leg. 
     A structural housing forms an interface between the upper end of each leg and the table top. Within this structural housing, a geared mechanism can be provided that enables a user to elevate the table top relative to an underlying support surface or floor. 
     At least one of the legs is supported by a lower foot that extends in front of and behind the leg. 
     The present invention includes an elevating table apparatus comprising a table top providing an upper work surface and a lower surface; a plurality of table legs, each leg including a pair of telescoping members including an inner member and a first outer sleeve member that has a bore that is receptive of the inner member; a second outer sleeve member that envelops the lower end of at least one of the table legs; wherein there are no connections that span in a generally horizontal direction from one leg to another leg other below said table top; wherein the second outer sleeve does not prevent telescoping movement of the table legs; a geared mechanism on each leg that enables a user to elevate the table top relative to an underlying support surface or floor; and a gear box housing that envelops the geared mechanism and that is structurally connected to both the table top and each leg; the gear box housing being connected to the leg below the geared mechanism; the gear box housing having an upper peripheral edge portion that is structurally connected to the table top and that extends radially out from the gear mechanism, and wherein the gear box housing surrounds the geared mechanism. 
     Preferably, the gear mechanisms are manually movable using a crank. 
     Preferably, at least one of the legs is supported by a lower foot that extends in front of and behind the leg. 
     Preferably, the inner member moves up and down relative to the first outer sleeve member. 
     Preferably, the first outer sleeve member moves up and down relative to the inner member. 
     Preferably, the present invention further comprises a caster fitted to the bottom of at least one of the legs. 
     Preferably, the lower foot has a socket that is receptive of the lower end of the leg and the lower end of the second outer sleeve member. 
     Preferably, each leg and foot are rotatable so that feet on multiple legs can be oriented to form an acute angle. 
     Preferably, the inner member and outer sleeves are generally cylindrically shaped. 
     The present invention includes an elevating table apparatus comprising a table top providing an upper work surface and a lower surface; a plurality of table legs, each leg including a pair of telescoping members including an inner member and a first outer sleeve member that has a bore that is receptive of the inner member, and wherein each leg has a minimum leg height and a maximum leg height; a second outer sleeve member that envelops the lower end of at least one of the table legs; wherein there are no connections that span in a generally horizontal direction from one leg to another leg other below said table top; and wherein the second outer sleeve does not prevent telescoping movement of the table legs, wherein said second outer sleeve has a height about equal to the minimum leg height. 
     The present invention includes an elevating table apparatus comprising a table top providing an upper work surface and a lower surface; a plurality of table legs, each leg including a pair of telescoping members including an inner member and a first outer sleeve member that has a bore that is receptive of the inner member; a second outer sleeve member that envelops the lower end of at least one of the table legs; wherein there are no connections that span in a generally horizontal direction from one leg to another leg other below said table top; wherein the second outer sleeve does not prevent telescoping movement of the table legs; a geared mechanism on each leg that enables a user to elevate the table top relative to an underlying support surface or floor; a gear box housing that envelops the geared mechanism and that is structurally connected to both the table top and each leg; and the gear mechanisms being simultaneously rotated during elevation and wherein load transfer between the table top and legs is via a said gear box housing. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements and wherein: 
         FIG. 1  is a perspective view of a preferred embodiment of the apparatus of the present invention; 
         FIG. 2  is another perspective view of a preferred embodiment of the apparatus of the present invention showing the table in an elevated position; 
         FIG. 3  is a fragmentary view of a preferred embodiment of the apparatus of the present invention; 
         FIG. 4  is a side, sectional view of an alternative embodiment of the apparatus of the present invention, taken along lines  4 - 4  of  FIG. 1 ; 
         FIG. 5  is a side sectional elevation view of a preferred embodiment of the apparatus of the present invention, taken along lines  5 - 5  of  FIG. 2 ; 
         FIG. 6  is a sectional elevation view of a preferred embodiment of the apparatus of the present invention; 
         FIG. 6A  is a fragmentary view of a preferred embodiment of the apparatus of the present invention; 
         FIG. 7  is a sectional view taken along lines  7 - 7  of  FIG. 6 ; 
         FIG. 8  is an enlarged sectional view of a preferred embodiment of the apparatus of the present invention; 
         FIG. 9  is a sectional view taken along lines  9 - 9  of  FIG. 8 ; 
         FIG. 10  is a sectional view taken along lines  10 - 10  of  FIG. 8 ; 
         FIG. 11  is a partial perspective view of a preferred embodiment of the apparatus of the present invention; 
         FIG. 12  is a partial perspective view of a preferred embodiment of the apparatus of the present invention; 
         FIG. 13  is a partial perspective view of a preferred embodiment of the apparatus of the present invention; 
         FIG. 14  is a perspective view of a second embodiment of the apparatus of the present invention; 
         FIG. 15  is a plan view of the second embodiment of the apparatus of the present invention; 
         FIG. 16  is a sectional, elevation view of a third embodiment of the apparatus of the present invention; 
         FIG. 17  is a fragmentary sectional elevation view of the third embodiment of the apparatus of the present invention; 
         FIG. 18  is a partial plan view of the third embodiment of the apparatus of the present invention; 
         FIG. 19  is a fragmentary view of the third embodiment of the apparatus of the present invention; 
         FIG. 20  is a fragmentary view of the third embodiment of the apparatus of the present invention; 
         FIG. 21  is a partial perspective exploded view of the third embodiment of the apparatus of the present invention; 
         FIG. 22  is a schematic plan view of the third embodiment of the apparatus of the present invention; 
         FIG. 23  is a schematic plan view of the third embodiment of the apparatus of the present invention illustrating multiple leg positions; and 
         FIGS. 24-25  are schematic views illustrating controllers for controlling operation of the third embodiment of the apparatus of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1-13  show a preferred embodiment of the apparatus of the present invention, designated generally by the numeral  10 . Height adjustable table  10  provides an expansive top  11  having a work surface  12 . Top  11  can be supported with a pair of spaced apart legs  13 ,  14 . Each leg  13 ,  14  is joined to a foot. The leg  13  connects to foot  15 . The leg  14  connects to foot  16 . 
     Table  10  can be height adjusted using crank  17 . Crank  17  is joined to a crank rod  18  that can be rotated as illustrated by arrow  19  in the drawings. The rod  18  is supported using rod support  20 . Rod  18  also extends to a structural gear box housing  21  as shown in  FIGS. 1 and 7 . 
     Each leg  13  has a lower section  23  and an upper section  24 . The upper section  24  moves up and down relative to lower section  23  as illustrated by arrow  25  in  FIG. 2 .  FIG. 1  illustrates a collapsed lowermost position of upper section  24 .  FIG. 2  illustrates an upper elevated position of upper section  24 . 
     Rod  26  extends between gear box housings  21 ,  22 . The gear box housing  21  is associated with leg  14 . The gear box housing  22  is associated with leg  13 . Each of the gear box housings  21 ,  22  provides a gear box arrangement as shown in  FIGS. 6 and 7 . Each gear box housing  21 ,  22  includes a gear cluster  32 . The gear cluster  32  includes a bevel gear  35  mounted at the upper end portion of externally threaded shaft  36 . The gear cluster  32  also includes a bevel gear  33  mounted upon an end of crank rod  18 . For the gear box housing  22 , it should be understood that there would not be a rod  18  nor bevel gear  33 . Instead, the gear box housing  22  would contain an externally threaded shaft  36  having bevel gear  35  and a bevel gear  34  mounted to an end portion of rod  26  that enters gear box housing  22 . 
     In  FIG. 6 , crank rod  18  can provide a rod telescoping section  27 . The rod telescoping section  27  can include a stop pin  28  that travels in slot  29 , as shown in  FIG. 3 . In this fashion, the crank  17  can be moved from a retracted position as shown in hard lines in  FIG. 3  to a operating position as shown in phantom lines in  FIG. 3  and in hard lines in  FIGS. 2 and 6 . Arrow  30  in  FIG. 3  illustrates movement of crank  17  between retracted and extended, operating positions. In  FIG. 6 , fasteners  31  can be used to secure gear box housing  21  and rod support  20  to the underside of expansive top  11 . Similarly, fasteners  31  can be used to secure gear box housing  22  to the underside of expansive top  11 . 
     In  FIGS. 6 and 6A , externally threaded shaft  36  has a lower end portion  37  that is fitted with stop  38 . Internally threaded sleeve  39  provides an internally threaded nut  40  that engages externally threaded shaft  36  as shown in  FIG. 6A . When stop  38  engages internally threaded nut  40 , maximum elevation of expansive top  11  is reached. Upper leg section  24  provides an upper tube  41 . Lower leg section  23  provides a lower tube  42 . A support sleeve  43  can be placed in between the lower end portion of the upper tube  41  and upper end portion of the internally threaded sleeve  39  (see  FIG. 6 ). The sleeve  39  can be a square tube, for example. 
     A foot  16  provides socket  44  that is receptive of lower tube  42  as shown in  FIG. 6 . Fasteners  45  form a connection between foot  16  and plate  46 . Plate  46  can be fastened to the lower end portion of tube  42  using welding, for example. A lower threaded nut  47  is embedded within the lower end portion of tube  39 . Fastener  48  centers tube  39  upon plate  46  and thus centers tube  39  with respect to tube  42  as shown in  FIG. 6 . Foot  15  or  16  can provide one or more casters  49  or fixed supports  50 , or one of each. In  FIG. 6 , a structurally robust connection is made between upper tube  41  and gear box housing  21 . Each gear box housing  21 ,  22  is generally bowl shaped, extending in front of and behind as well as on both sided of the gear box that is envelops. A peripheral edge of each housing is joined to the table top along a circumferentially spaced, radially spaced position relative to a leg and gearbox that it surrounds and envelops. A circular plate  63  provides an opening  64  through which externally threaded shaft  36  can pass. A connection  65  between tube  41  and gear box housing  21  can be for example a welded connection that includes welding to circular plate  63 . This connection enhances the moment load transfer capability between upper tube  41  to expansive top  11  over an elongated area designated by the dimension arrow  66  in  FIG. 6 . This arrangement thus eliminates the need for intermediate bracing which is typically found in the prior art, and that interferes with the knees of a user and/or with the storage of large items in the area under the table top  11 , such as computers. 
       FIGS. 8-13  show a guiding arrangement that interfaces upper tube  41  and lower tube  42 . Guides  51  are placed at circumferentially spaced apart positions on upper tube  41  as shown in  FIG. 10 . In  FIGS. 11 and 12 , each guide  51  has an elongated center section  52 , and enlarged upper section  53  and an enlarged lower section  54 . Each enlarged section  53 ,  54  provides a lug  55 . The lugs  55  enable each guide  51  to be mounted to sockets or openings in upper tube  41 . 
     Rib  56  is provided in each enlarged section  53 ,  54  opposite lug  55  as shown in  FIGS. 11 and 12 . The ribs  56  travel in channels  58  formed on the inside surface of lower tube  42 . 
     Slides  59  are mounted in openings  62  in lower tube  42 . Each slide  59  has an inner concave surface  60 . Each slide  59  provides a lug  61  for attaching to socket or opening  62  in lower tube  42 . 
       FIGS. 14 and 15  show a second embodiment of the apparatus of the present invention, designated generally by the numeral  10 A. Height adjustable table  10 A is similar to the preferred embodiment of  FIGS. 1-13 . In  FIGS. 14 and 15  however, a curved expansive top  11 A is provided having a work surface  12 A. Height adjustable table  10 A provides three legs  13 ,  14 ,  80 . Each of the legs  13 ,  14 ,  80  can be constructed in accordance with the preferred embodiment of  FIGS. 1-13 . The leg  80  provides a single wheeled caster  49 , while the feet  15 ,  16  can provide either a caster  49  or a fixed support  50  as shown in  FIG. 6 . 
     In  FIG. 15 , height adjustable table  10 A provides three gear box housings  21 ,  22  and  69 . The gear box housings  21 ,  22  are constructed in accordance with the preferred embodiment of  FIGS. 1-13 . The gear box  69  forms an interface between two rods  67 ,  68 . This arrangement is similar to that shown in  FIG. 7 . However, the rods  67 ,  68  form an obtuse angle as opposed to a ninety degree or right angle. In that regard, each rod  67 ,  68  provides bevel gears  33  or  34  at each end portion which engage a bevel gear  35  of an externally threaded rod  36 . 
       FIGS. 16-19  and  22 - 23  show a third embodiment of the apparatus of the present invention, designated generally by the numeral  10 C. Height adjustable table  10 C employs a telescoping leg  70  that can be used for a two-legged table ( FIG. 18 ), a three-legged table ( FIG. 22 ), or a table having more than three legs ( FIG. 23 ). In  FIG. 16 , telescoping leg  70  includes an upper elevating section  71  and a lower static section  72 . A third leg section is an outer tube  73  that is also static and that surrounds the combination of upper elevating section  71  and lower static section  72 . This arrangement of the three sections can be seen in  FIGS. 16 and 17 . 
     Externally threaded shaft  75  extends from gear box housing  79  downwardly to internally threaded nut  74  which is mounted in the upper end portion of lower static section  72 , as shown in  FIG. 17 . The lower end of externally threaded shaft  75  provides a stop  76 . When elevating the table  10 C, expansive top  81  and its work surface  82 , a maximum elevation is reached when stop  76  contacts internally threaded nut  74 . 
     Leg  70  can be mounted in a foot such as  15  or  16  using a connection similar to that shown in  FIG. 6 . In  FIG. 16 , plate  77  is provided at the lower end portion of lower static section  72 . Fasteners  78  can extend through openings in foot  15 ,  16  to connect with plate  77 . In that regard, plate  77  can have multiple internally threaded sockets that are receptive of fasteners  78 . 
     Gear box housing  79  preferably extends a distance  66  that is about equal to or greater than one half the depth of expansive top  81 , as shown in  FIG. 16 . As with the preferred embodiment, a robust connection is formed between leg  70  and gear box housing  79 . Gear box housing  79  connects to upper elevating section  71  at circular plate  83 . Plate  83  has an opening  84  that enables externally threaded shaft  75  to extend through plate  83  and engage motor drive  90 , as will be described more fully hereinafter. A welded or like connection can be formed between the three parts that include gear box housing  79 , circular plate  73 , and upper elevating section  71  of leg  70 . As with the preferred embodiment, this connection enables a high moment load transfer between table top  81  and leg  70 , eliminating the need for intermediate supports between legs and below the top  81 . 
     The outer tube  73  is a static tube that is connected to a foot  15  or  16  using adhesive, an interference fit, a threaded connection, or other connection such as a friction fit using for example one or more set screws  85  (see  FIG. 16 ). The upper elevating section  71  thus travels in between lower static section  72  and outer tube  73 . The outer tube  70  can be provided in a number of different colors so that a user can match table  10 C of the present invention to a selected decor. 
     In the embodiment of  FIGS. 16-19 , a motor drive  90  is provided for each gear box housing  79  associated with each leg  70 . For the table  10 C shown in  FIG. 18 , there are two legs  70 , two gear box housings  79 , and two motor drives  90 .  FIG. 19  illustrates the details of construction of motor drive  90 . The motor drive  90  includes an electric motor  86  having a motor shaft  87  fitted with a worm gear  88 . Worm gear  88  engages pinion gear  89  that is mounted to the upper end of externally threaded shaft  75 . For the embodiment of  FIGS. 16-18 , each leg  70  has a motor drive  90 . Those motor drives  90  are synchronized so that when a user activates operating panel  91 , the legs  70  selectively elevate at the same time (using keypad arrow  92 ) and at the same rate or descend at the same time (using keypad arrow  93 ) and at the same rate. 
       FIGS. 20 ,  24  and  25  illustrate that different controllers can be used. In  FIG. 20 , up arrow  92  and down arrow  93  are provided for enabling an operator to elevate or descend expansive top  81 . Keypad numerals  94 ,  95 ,  96  enable an operator to input a code that “remembers” the position of the table top  81 , such as for example when several users are using table  10 C at different times. The key number “s”, designated by numeral  97  provides a “set” function that identifies a certain code with a certain elevation of a table after a user has input a selected code using the keys  94 - 96 . 
       FIG. 24  is a simpler arrangement, where only up and down arrows  92 ,  93  are provided.  FIG. 25  is similar to  FIG. 20  with the addition of a digital readout  98 . 
       FIGS. 22 and 23  illustrate that multiple legs  70  can be employed, such as three legs  70  of  FIG. 22  or even more legs in  FIG. 23 , in that the motor drives  90  are synchronized. 
     The following is a list of parts and materials suitable for use in the present invention. 
     
       
         
               
             
               
               
               
             
               
               
               
               
             
           
               
                   
               
               
                 PARTS LIST 
               
             
          
           
               
                   
                 Part Number 
                 Description 
               
               
                   
               
             
          
           
               
                   
                   
                 10 
                 height adjustable table 
               
               
                   
                   
                 10A 
                 height adjustable table 
               
               
                   
                   
                 10B 
                 height adjustable table 
               
               
                   
                   
                 10C 
                 height adjustable table 
               
               
                   
                   
                 11 
                 expansive top 
               
               
                   
                   
                 11A 
                 expansive top 
               
               
                   
                   
                 12 
                 work surface 
               
               
                   
                   
                 12A 
                 work surface 
               
               
                   
                   
                 13 
                 leg 
               
               
                   
                   
                 14 
                 leg 
               
               
                   
                   
                 15 
                 foot 
               
               
                   
                   
                 16 
                 foot 
               
               
                   
                   
                 17 
                 crank 
               
               
                   
                   
                 18 
                 crank rod 
               
               
                   
                   
                 19 
                 arrow 
               
               
                   
                   
                 20 
                 rod support 
               
               
                   
                   
                 21 
                 gear box housing 
               
               
                   
                   
                 22 
                 gear box housing 
               
               
                   
                   
                 23 
                 lower section 
               
               
                   
                   
                 24 
                 upper section 
               
               
                   
                   
                 25 
                 arrow 
               
               
                   
                   
                 26 
                 rod 
               
               
                   
                   
                 27 
                 rod telescoping section 
               
               
                   
                   
                 28 
                 stop pin 
               
               
                   
                   
                 29 
                 slot 
               
               
                   
                   
                 30 
                 arrow 
               
               
                   
                   
                 31 
                 fastener 
               
               
                   
                   
                 32 
                 gear cluster 
               
               
                   
                   
                 33 
                 bevel gear 
               
               
                   
                   
                 34 
                 bevel gear 
               
               
                   
                   
                 35 
                 bevel gear 
               
               
                   
                   
                 36 
                 externally threaded shaft 
               
               
                   
                   
                 37 
                 lower end portion 
               
               
                   
                   
                 38 
                 stop 
               
               
                   
                   
                 39 
                 internally threaded sleeve 
               
               
                   
                   
                 40 
                 internally threaded nut 
               
               
                   
                   
                 41 
                 upper tube 
               
               
                   
                   
                 42 
                 lower tube 
               
               
                   
                   
                 43 
                 support member 
               
               
                   
                   
                 44 
                 socket 
               
               
                   
                   
                 45 
                 fastener 
               
               
                   
                   
                 46 
                 plate 
               
               
                   
                   
                 47 
                 lower threaded nut 
               
               
                   
                   
                 48 
                 fastener 
               
               
                   
                   
                 49 
                 caster 
               
               
                   
                   
                 50 
                 fixed support 
               
               
                   
                   
                 51 
                 guide 
               
               
                   
                   
                 52 
                 center section 
               
               
                   
                   
                 53 
                 upper section 
               
               
                   
                   
                 54 
                 lower section 
               
               
                   
                   
                 55 
                 lug 
               
               
                   
                   
                 56 
                 rib 
               
               
                   
                   
                 57 
                 socket 
               
               
                   
                   
                 58 
                 channel 
               
               
                   
                   
                 59 
                 slide 
               
               
                   
                   
                 60 
                 concave surface 
               
               
                   
                   
                 61 
                 lug 
               
               
                   
                   
                 62 
                 socket 
               
               
                   
                   
                 63 
                 circular plate 
               
               
                   
                   
                 64 
                 opening 
               
               
                   
                   
                 65 
                 connection 
               
               
                   
                   
                 66 
                 dimension arrow 
               
               
                   
                   
                 67 
                 first rod 
               
               
                   
                   
                 68 
                 second rod 
               
               
                   
                   
                 69 
                 gear box housing 
               
               
                   
                   
                 70 
                 telescoping leg 
               
               
                   
                   
                 71 
                 upper elevating section 
               
               
                   
                   
                 72 
                 lower static section 
               
               
                   
                   
                 73 
                 outer tube 
               
               
                   
                   
                 74 
                 internally threaded nut 
               
               
                   
                   
                 75 
                 externally threaded shaft 
               
               
                   
                   
                 76 
                 stop 
               
               
                   
                   
                 77 
                 plate 
               
               
                   
                   
                 78 
                 fastener 
               
               
                   
                   
                 79 
                 gear box housing 
               
               
                   
                   
                 80 
                 leg 
               
               
                   
                   
                 81 
                 expansive top 
               
               
                   
                   
                 82 
                 work surface 
               
               
                   
                   
                 83 
                 circular plate 
               
               
                   
                   
                 84 
                 plate opening 
               
               
                   
                   
                 85 
                 set screw 
               
               
                   
                   
                 86 
                 electric motor 
               
               
                   
                   
                 87 
                 shaft 
               
               
                   
                   
                 88 
                 worm gear 
               
               
                   
                   
                 89 
                 pinion gear 
               
               
                   
                   
                 90 
                 motor drive 
               
               
                   
                   
                 91 
                 operating panel 
               
               
                   
                   
                 92 
                 arrow 
               
               
                   
                   
                 93 
                 arrow 
               
               
                   
                   
                 94 
                 key pad numeral 
               
               
                   
                   
                 95 
                 key pad numeral 
               
               
                   
                   
                 96 
                 key pad numeral 
               
               
                   
                   
                 97 
                 set key 
               
               
                   
                   
                 98 
                 digital readout 
               
               
                   
               
             
          
         
       
     
     All measurements disclosed herein are at standard temperature and pressure, at sea level on Earth, unless indicated otherwise. All materials used or intended to be used in a human being are biocompatible, unless indicated otherwise. 
     The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims.