Abstract:
The present disclosure provides tables having a tabletop whose height is adjustable. A table according to the present disclosure is useful among other employments as a coffee table whose height can be varied to suit the needs of persons using the table for various purposes, including game playing. A table with adjustable height top portion according to the disclosure attractive and functional. Various structures for maintaining the selected height at which the table top is set are disclosed.

Description:
FIELD OF THE INVENTION 
     This invention relates to furniture, and more particularly to tables, and especially to tables whose top portion is adjustable in height. 
     BACKGROUND 
     Tables have been known since the most ancient times. In general, tables may take on the roles of either a functional surface upon which various articles, implements, decorations, etc. may be placed, or are decorative in nature or both. Most common persons desiring to add a table to their existing decor will look to conventional suppliers of tables, and make their selection based upon the tables which are available from these suppliers. Oftentimes, a compromise must be made between functionality and appearances, since it is desirable in most home environments to first and foremost have a table which matches the decor in the room in which the table is intended to reside. However, table manufacturers do not in general offer tables of the same outer appearance having table top portions disposed at various height levels from the floor upon which the table rests, but rather have adopted in the industry standard heights. Thus, if a person were desirous of having a table which matched their decor in the room selected for the table which table also had a specific height, such a table would not be readily available and would probably need to be custom fabricated. 
     In addition, it is not always desirable to have the tabletop of a table disposed at the same height with respect to the floor on which the table as a whole resides, but convenience would require the height of the table top to be adjustable with respect to the floor level. Being able to alter the height of the table top of a table adds versatility to the overall functionality of a table. 
     It is thus an object of the present invention to provide a table having a top portion whose height level is adjustable. It is also an object of the present invention to provide a height-adjustable table whose height may be varied with a minimal amount of force by the user, through the use of biasing springs. It is also an object of the present invention to provide a height-adjustable table which can be locked in place in any height desired by the user. These and other objects and advantages are provided by the present invention. 
     SUMMARY OF THE INVENTION 
     The present invention provides a height-adjustable table comprising a base portion having length, width, and height dimensions, and comprising a top portion, bottom portion, two face portions, and two end portions. There is a track means disposed on the top portion of the base portion, wherein the track means comprises a first linear track member and a second linear track member, wherein the track members are oriented parallel to one another, and wherein each of the track members include a slot, wherein the slot on the first linear track member and the slot on the second linear track member are oriented in a parallel configuration with respect to one another. There is a scissoring support means which comprises: i) a linear first pivoting support having an upper end portion and a lower end portion; ii) a linear first slidable pivoting support having an upper end portion and a lower end portion; iii) a linear second pivoting support having an upper end portion and a lower end portion; iv) a linear second slidable pivoting support having an upper end portion and a lower end portion. The first pivoting support and the second pivoting support are connected to one another at their upper end portions by means of a linear upper pivoting support connector and wherein the first pivoting support and the second pivoting support are connected to one another at their lower end portions by means of a linear lower pivoting support connector. The first slidable pivoting support and the second slidable pivoting support are connected to one another at their upper end portions by means of a linear upper slidable pivoting support connector and wherein the first slidable pivoting support and the second slidable pivoting support are connected to one another at their lower end portions by means of a linear lower slidable pivoting support connector. The first pivoting support and the first slidable pivoting support are pivotally connected to one another at a point along their lengths, and the second pivoting support and the second slidable pivoting support are pivotally connected to one another at a point along their lengths. The first and second slidable pivoting supports each have a pin disposed at their lower end portions which pins engage into the slots of the linear track members. There is a platen which comprises a first platen width support, a first platen length support, a second platen width support, and a second platen length support, wherein the width supports are oriented parallel to one another, the first platen width support and the second platen width support each including a slot disposed in their face portion which faces the interior space between them, the platen being hingedly connected to the upper end portions of the first pivoting support and the second pivoting support, and wherein the first and second slidable pivoting supports each further comprise a pin disposed at their upper end portions, which pins engage into the slots of the first platen width support and the second platen width support. There is a table top portion, the table top portion being attached to the platen. A table according to the invention also includes a means for maintaining the platen at a selected height above the top portion of the base portion, as further described herein. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     In the annexed drawings: 
     FIG. 1 is a perspective view of a height-adjustable table according to one form of the invention; 
     FIG. 2 is a perspective view of a mechanism useful for providing a height-adjustable table according to one form of the invention; 
     FIG. 3 is a perspective view of a portion of a mechanism useful for providing a height-adjustable table according to one form of the invention 
     FIG. 4 is a side view of a locking mechanism useful for maintaining a table top at a selected height in accordance with one form of the present invention; 
     FIG. 5 is a perspective view of a height-adjustable table according to one form of the invention; 
     FIG. 6 is a bottom view of a clamping means useful in maintaining the table top portion of a table according to the invention in a selected height position; 
     FIG. 7 is a bottom view of a clamping means useful in maintaining the table top portion of a table according to the invention in a selected height position; 
     FIG. 8 is a perspective view of a height-adjustable table according to one form of the invention; 
     FIG. 9 is a perspective view of a height-adjustable table according to one form of the invention; 
     FIG. 10 is a perspective view of a clamping means useful in maintaining the table top portion of a table according to the invention in a selected height position 
     FIG. 11 is a side view of a clamping means useful in maintaining the table top portion of a table according to the invention in a selected height position 
     FIG. 12 is a bottom view of a clamping means useful in maintaining the table top portion of a table according to the invention in a selected height position 
     FIG. 13 is a perspective view of a clamping means useful in maintaining the table top portion of a table according to the invention in a selected height position 
     FIG. 14 is a side view of a clamping means useful in maintaining the table top portion of a table according to the invention in a selected height position 
     FIG. 15 is a bottom view of a clamping means useful in maintaining the table top portion of a table according to the invention in a selected height position. 
    
    
     DETAILED DESCRIPTION 
     Referring to the drawings and initially to FIG. 1 there is shown a height-adjustable table assembly  10  according to the present invention. Such table assembly comprises a base portion that includes a first table top length support  27 , first table top width support  29 , second table top length support  31 , and a second table top width support  33 , disposed with respect to one another so that their edges form, generally, a planar rectangular construct upon which a flat, rectangular table top such as  11 , may be caused to rest. However, the present invention differs from tables of the prior art in the fact that the table top  11  is readily height adjusted by the table&#39;s user, to accommodate various desired height settings by the user when altering the height of the table top  11  is deemed desirable or beneficial for a particular use. 
     The general mechanism by which a table top according to the invention is caused to be vertically adjustable is by means of a first sub-assembly comprising a first pivoting support  13  and second pivoting support  17 , and a second sub-assembly comprising a first slidable pivoting support  15 , and a second slidable pivoting support  19 , disposed as shown, and wherein the first and second sub-assemblies are pivotally connected to one another at pivot points  21   a  and  21   b . The lower portion of the first slidable pivoting support  15  is connected to the lower portion of the second slidable pivoting support  19  by means of lower slidable pivoting supports connector  35 , and the end portions of these slidable pivoting supports are fitted with a guide pin  39  on their exterior faces, which guide pins ride inside a track portion  41  disposed on the first track member  23 . There is a corresponding arrangement existing at the end portion of the second slidable pivoting support and the second track member  25 . Additionally, there is a lower pivoting supports connector  37  disposed connectively between the lower end portions of the first pivoting support and the second pivoting support. In one preferred form of the invention, the first and second track members  23  and  25 , respectively, are affixed using conventional means such as screws, nails, glue rivets, etc. to the first table top length support  27  and the second table top length support  31 ; however, equivalent structures are possible. 
     FIG. 2 shows the arrangement of the various connections between the elements of the pivoting support sub-assemblies about the top portion of a platen assembly to which the table top  11  is affixed in a table according to the invention. The platen comprises a first platen width support  43 , a first platen length support  45 , a second platen width support  47 , and a second platen length support  49 , all arranged so that one of their edge portions lie substantially in the same plane upon which table top portion  11  (FIG. 1) is intended to reside. The first platen width support  43  and second platen width support  47  are each provided with a linear slot  69  disposed on their faces which lie on the interior of the polygon comprising the platen assembly. 
     Shown again is the slidable pivoting support assembly which comprises the first slidable pivoting support  15  and second slidable pivoting support  19 , connected at their upper ends by means of upper slidable pivoting supports connector  85 , and at their lower ends by lower slidable pivoting supports connector  35 . 
     There is also the pivoting support assembly which comprises the first pivoting support  13  and second pivoting support  17 , connected at their upper ends by means of an upper pivoting supports connector  101  (FIG.  5 ), and at their lower ends by lower pivoting supports connector  37 . The slidable pivoting support assembly and the slidable support assembly are connected to one another as shown at pivot points  21   a  and  21   b.    
     Disposed at the lower end portions of the first slidable pivoting support  15  and second slidable pivoting support  19 , and protruding from the outer face portions thereof there are guide pins  39  (FIG. 3) which reside in slidable arrangement within a linear slot  41  disposed in the face portion of the first track member, with identical features and relationship existing between a slot similarly disposed within the second track member  25  and a guide pin  39  at the lower end of the second slidable pivoting support  19 . The upper ends of the first slidable pivoting support  15  and second slidable pivoting support  19  are connected to one another by means of upper slidable pivoting supports connector  85 . Disposed at the upper end portions of the first slidable pivoting support  15  and second slidable pivoting support  19 , and protruding from the outer face portions thereof there are guide pins (not shown) analogous to  39  which reside within the linear slot  69  of the first platen width support and a corresponding slot on the second platen width support  47 . 
     The first pivoting support  13  and second pivoting support  17  of the pivoting support assembly are pivotally connected to the first track member  23  and second track member  25  at their lower ends, respectively, using conventional means such as screws, nails, etc. In one preferred form of the invention, spacer blocks  129  and  131  are disposed between the track members and the lower portions of the first and second pivoting supports to compensate for the thicknesses of the first and second slidable pivoting supports, and spacer blocks  133  and  135  are disposed between the upper ends of the first and second pivoting supports  13  and  17 , and the first platen width support  43  and second platen width support  47 . The first pivoting support  13  and second pivoting support  17  of the pivoting support assembly are pivotally connected to the first platen width support  43  and second platen width support  47  at their upper ends, respectively, using conventional means such as screws, nails, etc. In one preferred form of the invention, spacer blocks are disposed between the platen width supports and the upper portions of the first and second pivoting supports to compensate for the thicknesses of the first and second slidable pivoting supports. 
     Under such an arrangement as that described in this FIG. 2, the top planar surface of the platen assembly upon which the table top portion  11  is intended to rest is vertically moveable with respect to the plane formed by the edges of the table top length and width supports, i.e., the platen is height-adjustable. However, the forces of gravity acting on the scissoring assembly will lower the platen so that the common upper edges of its components, e.g., the first platen width support  43 , first platen length support  45 , second platen width support  47 , and second platen length support  49 , will be at the same level as the common upper edges of the first table top length support  27 , first table top width support  29 , second table top length support  31 , and second table top width support  33 , in the absence of a means for maintaining the platen at a desired height. The present invention provides such means for maintaining the platen at a desired height. 
     Also shown in FIG. 2 is the lock frame  73  which is useful in maintaining the platen at a desired height, in conjunction with other elements of the invention as yet to be described. The lock frame includes a plate portion  77  to which supports  75  are affixed by conventional means, and which supports contain the cammed control rod  57  having handle  71  in such a way that when the handle  71  is moved in a direction indicated by arrow labeled D, the cammed ends of the cammed control rod move in a direction indicated by the arrows labeled U. The plate  77  is mounted to the inside face of the first platen length support  45 , as shown by arrow A. 
     In FIG. 3 is shown the platen, and some of the elements of the pivoting support assembly and the slidable pivoting support assembly, including the first platen width support  43 , first platen length support  45 , second platen width support  47 , second platen length support  49 , first pivoting support  13 , first slidable pivoting support  15 , second pivoting support  17 , and second slidable pivoting support  19 . The guide pins  39  are shown disposed at the lower ends of the first and second slidable pivoting supports  15  and  19  and protruding outward in a direction which enables them to reside within the linear slots  41  disposed in the interior face portions of the first track member  23  and second track member  25  (FIG.  1 ). Similarly, there are guide pins  39  disposed at the upper ends of the first and second slidable pivoting supports  15  and  19  and protruding outward in a direction which enables them to reside within the linear slots  41  disposed in the interior face portions of the first platen width support  43  and second platen width support  47 . The plate  77  of the lock frame ( 73 , FIG. 2) is affixed to the interior face of the first platen length support so that the end portion of the cammed control rod  57  is in the vicinity of the junction of the first platen width support  43  and the first platen length support  45 . There is a toothed rod  55  which is pivotally affixed to the interior face portion of the first platen width support  43  using conventional fastening means. The toothed rod  55  is configured so that its toothed portions are adapted to ride on the guide pin  39  which is disposed at the top portion of the first slidable pivoting support  15 . Preferably, the toothed rod is flat, and is disposed between the first slidable pivoting support  15  and the face of the first platen width support  43  as further shown in FIG.  4 . 
     FIG. 4 is a side view of a means for maintaining the height of the platen of the present invention in a desired position, and shows the toothed rod  55  being pivotally attached at  59  to the interior face portion of the first platen width support  43 . The first pivoting support  13  is shown pivotally connected to the first platen width support  43  at connection point  61 , with spacer block  133  disposed between the upper end portion of the first pivoting support  13  and the interior face of the first platen width support  43 . First slidable pivoting support  15  is shown pivotally attached to the first pivoting support  13  at pivot point  21   a , and comprises a guide pin  39  which engages one of the depressions along the length of the toothed rod, thus maintaining the platen at a desired height. The end portion of the cammed control rod  57  is seen in sectional view, upon which the flat end portion  67  of the toothed rod rests, so that when the handle  71  (FIG. 2) is pushed in a downward direction, the end portion of the cammed control rod  57  exerts an upward force on the flat portion  67  of the toothed rod  55  in the direction of the arrow, thus disengaging the guide pin  39  from the depression in the toothed rod, enabling the first pivoting support and first slidable pivoting support to pivot about point  21   a  and thus enabling the height of the platen to be lowered. 
     FIG. 5 shows another embodiment of the present invention having an alternative means for securing the platen portion in a desired location above the rest of the table  10  according to the invention. This alternative means includes a housing  83  disposed about and in mechanical contact with the upper slidable pivoting supports connector  75 , and includes a provision for the passage therethrough of a second toothed rod  79  having a handle  81  disposed on one of its end portions. The second toothed rod  79  passes through the first platen length support  45  near the end portion having the handle  81 , whilst the other end of the second toothed rod is pivotally engaged with or rotably connected to the interior face portion of the second platen length support  49 , which may be by means of a dimple within the second platen length support, or other functionally equivalent alternative such as a bearing. Thus, the housing is disposed about the second toothed rod and the housing is simultaneously in rigid mechanical contact with the upper slidable pivoting supports connector. The housing includes a hollow channel space through which the toothed rod may be moved. The housing, comprising at least one cross bar oriented parallel to the upper slidable pivoting supports connector, causes the cross bar to be in sufficient position to engage the spaces between the teeth when the toothed rod is oriented with its teeth towards the cross bar so as to prevent motion of the toothed rod with respect to the upper slidable pivoting supports connector when the cross bar is engaged within a space between the teeth 
     FIG. 6 shows an underside view of the housing  83  in the proximity of the second toothed rod  79 , showing how the spaces between the teeth  87  on the second toothed rod  79  are disposed on both sides of cross bars  89  and in such position lateral movement of the guide pins  39  disposed at the ends of the first slidable pivoting support  15  and the second slidable pivoting support within the slots  69  is precluded, thus maintaining the platen portion as a whole in a desired vertical altitude. However, by rotation of the handle  81  by an amount of 90°, the teeth  87  are caused to be oriented perpendicularly to the cross bars  89 , which, as shown in FIG. 7, permits adjustment of the vertical altitude of the platen portion, as shown in FIG. 8 as a non-limiting example of an embodiment in which the platen is lowered in its vertical altitude with respect to the position depicted earlier in FIG.  5 . 
     FIG. 9 shows another embodiment of the present invention having an alternative means for securing the platen portion in a desired location above the rest of the table  10  according to the invention. In this embodiment there is a clamp means  93  disposed about and in mechanical contact with the a bar  103  as more clearly shown in FIG. 10 in which the clamp means  93  is shown to be slidably disposed about the bar  103 , which itself is in turn affixed to the upper slidable pivoting supports connector  85  by conventional means such as a weld W. The clamp means  93  comprises a base portion  111  having a plurality of holes  137  through which it is affixed to the table top portion  11  (FIG.  1 ), and a pair of slots disposed through its surface which slots are adapted to receive the end portions of the left locking tang  107  and right locking tang  109 . There is a center support  121  affixed to the base portion  111  in a perpendicular orientation, and the right and left locking tangs and center support all contain holes through them which is adapted to enable the bar  103  of circular cross-section to be passed through each of these elements in a finished construct according to the invention. There is also a stop  113  positioned as shown, whose function is to limit the movement of the right and left locking tangs. Control rod  91  is shown attached to the lever control arm  119 , which itself is shown to be connected to the right locking tang  109  by means of the first connector lever  115 . Thus, pulling on control rod  91  towards the left in FIG. 10 ultimately causes the right locking tang to be adjusted to a position which is more perpendicular to the base portion  111  than instantly shown in FIG. 10, thus relieving the interference grasp exerted by the right locking tang on the bar  103  and thus enabling the bar  103  to slide freely through the clamping means  93 . Springs  105  function to mechanically bias the right and left locking tangs  107  and  109  towards the positions depicted in FIG. 10, with said locking tangs providing interference resistance to the motion of the bar  103  when in the orientation shown. Moving the control rod  91  to the left in FIG. 10 relieves the interference and enables the sliding of the bar  103  through the clamping means  93 , which by virtue of the bar  103  being connected to the upper slidable pivoting supports connector  85 , enables up and down adjustment of the altitude of a table top portion  11  which is affixed to the base portion  111  of the clamping means  93 , as shown in cross section in FIG.  11 . Here, the table top  11  is shown held in place against the base portion  11  of the clamping means  93  by means of screws  123 . The control rod  91  is in contact with the right and left locking tangs ( 109  and  107 ) by means of the first connector lever  115  and second connector lever  117 , the arrangement of which is more clearly shown in FIG. 12 subsequent. FIG. 11 shows a spacer  12  disposed about the fastening means  139  to enable smooth motion of the elements comprising the clamping means, which are generally flat pieces of metal having holes through their surfaces at the points of connection to the remaining elements of this clamping means. The connections between the elements are made using conventional fasteners, and are sufficiently loose to enable smooth pivoting of the various elements with respect to one another. 
     FIG. 12 is a bottom view of the clamping means  93  which more clearly shows the arrangement of the various elements of the clamping means including the base portion  111 , control rod  91 , lever control arm  119 , first and second connector levers  115  and  117  respectively, left and right locking tangs  107  and  109 , and bar  103 . Thus, FIGS. 10,  11 , and  12  show a clamping means  93  according to one preferred form of the invention in a locked position disposed about the bar  103 . 
     FIGS. 13,  14 , and  15 , on the other hand, show the same views as for FIGS. 10,  11 , and  12  previously, however, with the exception that the control rod  91  has now been pulled towards the left direction in FIG. 10, and thus the views of FIGS. 13,  14 , and  15  are those showing the clamping means in the non-locked position about the bar  103  in which the bar  103  is enabled to slide through the clamping means, and thus to enable the vertical altitude of the table top  11  affixed to the base portion  111  to be adjusted to a desired level. By providing a table according to the invention having such a clamping means and with easy access to the control rod  91 , a possessor of such a table can readily adjust the vertical height of the table. 
     According to one preferred embodiment of the present invention, there are springs  141  and  143  located at the end portions of and disposed about the upper pivoting supports connector  101  (FIGS.  2 , 3 ,  8 ). These springs are coiled about the upper pivoting supports connectors and each have two arms, one of which is in each case in contact with the spacer blocks  133 ,  135  and the other of which in each case is in contact with the second platen length support  49 . Springs  141  and  143  and are in a most compressed position when the platen is in its lowermost position, that is, as the platen is raised, the potential energy stored in the springs decreases. Such a feature reduces the force which a person must exert when raising or lowering the platen and makes use of a table according to the invention a very light task. 
     Connections between the various elements of a table according to the present invention are made using conventional fastening means, such as glue, wood screws, sheet metal screws, rivets, welds, etc. 
     A table according to the present invention appears as any other table having a flat top, because the mechanisms for adjustment of the table top altitude with respect to the frame, or base portion, to which it is ultimately attached are concealed beneath the table top portion  11 . A table according to the invention is simple to use. Once supplied and placed into the position within a room at which it is desired to be located, a person desiring to raise the height of the table top portion  11  merely disengages the particular means for maintaining the platen at a selected height above said top portion of said base portion, and lifts or permits the table top portion  11  to be raised or lowered into a desired position, at which point the means for maintaining the platen at a selected height is returned to its locked position. Such means have been described herein as those embodied in the various figures. However, consideration must be given to the fact that although this and other features of the present invention have been described and disclosed in relation to certain preferred embodiments, obvious equivalent modifications and alterations thereof will become apparent to one of ordinary skill in this art upon reading and understanding this specification and the claims appended hereto. Accordingly, the presently disclosed invention is intended to cover all such modifications and alterations, and is limited only by the scope of the claims which follow at the end of this specification. 
     The materials from which a table according to the present invention may be constructed include those materials recognized by those skilled in the art of building furniture and other fixtures, and include without limitation various woods, plastics, polymers, composites, metals, alloys, conglomerates, particle boards, masonite, plywood, glass, etc. 
     A table made in accordance with the present invention has many potential uses, including use as a game table during the play of a game such as chess, in which it is desired to raise the level of the game board. In such regard, a table according to the invention may be a coffee table. Another employment for a table according to the invention is as an examination table for animals within a veterinary medicine practice, to adjust the height of the plane upon which an animal is disposed during an examination or surgical process. Of course a table according to the invention may also be used by surgeons who operate on human patients, within a hospital setting. Accordingly, for convenience, the present invention contemplates the use of mechanized motion for altering the height of the platen portion with respect to the base portion of a table according to the invention, such as motors and gears, etc. for automating the raising and lowering of the platen portion.