Abstract:
A workbench with an adjustable height top dually engaged by twin standards with each standard having a single pawl-like structure laterally extended from front to back. The pawl mechanism in each standard is a laterally extended round rod engaging a vertical array of rounded ratchet apertures at the front and back end of the top. A novel safety mechanism to prevent inadvertent disengagement of the rod from the ratchet apertures is a combination of a tension spring connected between a chain and a foot actuator pedal. This spring prevents accidental release of the rod by absorbing unintentional or inadvertent minor force applied to the pedal. The rod-like structure or pawl provides superior structural rigidity for the bench when restricted with rear shims to rotation into the ratchet slots at an angle α between less than about 45 degrees and greater than about 10 degrees.

Description:
PRIORITY DATE CLAIMED  
         [0001]    A priority date of Dec. 7, 2001 is claimed based on filing of a provisional application in the U.S. of America, application serial No. 60/340,348 for this invention.  
         BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    This novel invention is related to mechanical improvements in adjustable height non-inclinable worktables used to support large heavy work objects during a process involving constructing, carving, sculpturing, and/or manufacturing.  
           [0004]    2. Description of Prior Art  
           [0005]    In 1874 Semmendinger was issued U.S. Pat. No. 149,255 for an improvement in camera stands. A camera stand platform was made readily adjustable to a particular height using a load-bearing lever with a roller at the platform support end connected to a manual pawl detent and ratchet assembly.  
           [0006]    Morey et al. received U.S. Pat. No. 1,650,293 on Nov. 22, 1927 entitled “Hospital Furniture”. The Morey et al. invention of the prior art relates to improvements in hospital furniture, and has for its primary object the provision of a bed side table, particularly adapted for use in hospitals, with which is combined an adjustable and collapsible shelf structure, of which the latter is of such form and mounting that when not in use the same may occupy a folded or collapsed position lying parallel and adjacent to one side of the table, and when in an active position may be extended so as to provide a support permitting the placing of articles, such as food trays and the like, thereon.  
           [0007]    Another aspect of the prior art invention resides in the provision of a hospital table with which is combined a foldable shelf structure, and wherein the supporting means for the shelf structure includes a non-rotatable vertical standard slidably supported within fixed guides carried by the side of the table, and wherein the standard is provided with a plurality of ratchet teeth cooperative with a pivoted locking detent which serves to maintain the standard locked automatically in any of its elevated positions of adjustment, so that the shelf or ledge carried in connection with the standard may be positioned at any desired elevation necessary to suit the convenience of the patient, and to adapt the shelf structure either to project over the bed of a reclining patient, or to permit the lowering of the same for use when the patient is occupying a chair or to maintain the shelf in any desired horizontal plane of adjustment.  
           [0008]    A further prior art aspect resides in the provision of a foot operated releasing means by which the detent may be removed from engagement with the teeth of the shelf supporting standard so as to allow the latter to be lowered to assume a folded or inactive position.  
           [0009]    Another prior art aspect is providing the upper end of the standard with a bifurcated head to which is pivotally connected one end of the supporting shelf, in order that when the shelf is lowered the same will lie closely adjacent and parallel to the side of the table upon which it is mounted and when raised the shelf will be swung to assume a position perpendicular to the table, novel locking and releasing means being provided for maintaining the shelf in its extended or active position where the shelf lies in a horizontal plane substantially at right angles to the table.  
           [0010]    Other aspects of the Morey et al. invention reside in the provision of a table of a character wherein the shelf structure may be raised, lowered and adjusted with convenience and facility, and wherein the locking mechanism is of a positive and automatic character, devoid of set screws and the like to the end of assuring the retention of the shelf structure in any desired position of adjustment.  
           [0011]    Noteworthy of the applicant&#39;s novel invention is that the Morey et al. invention teaches away from any adaptation of its mechanism to a table top which is so heavy and massive compared to the mass of the standard that support of same in a horizontal position by a single standard cannot be achieved due to the center of gravity of the combined structure extending so much away from the standard as to cause it to tilt and fall over.  
           [0012]    Likewise, Hall&#39;s U.S. Pat. No. 1,687,128, which issued on Oct. 9, 1928 for a combination stool, chair, and table discloses a horizontal surface supported with one (central) adjustable vertical standard with the surface area of the horizontal surface being variable. A cantilevered tray supported on one edge wherein the elevating and actuating is done with one foot is suggested and disclosed in the bedside table patented by Walter on Apr. 28, 1931 in U.S. Pat. No. 1,802,362. Walter&#39;s tray is not adapted for the support of substantial weight where the center of gravity of the table is such that it would readily tilt over.  
           [0013]    On Nov. 22, 1932 Steidl received U.S. Pat. No. 1,888,478 for a combination table. Steidl, to enable easy adjustment of the table top and standard, counterbalanced it with a spring that he located inside a hollowed out standard, which centrally supported the top. For securing the table at various vertical heights, Steidl used a pawl and ratchet connection between the standard and a base. The ratchet was formed in or carried by the side of the standard and consisted of a set of upwardly faced pointed ratchet saw teeth. The saw teeth have at their supporting base surface abruptly shouldered seats on which the pawl rests. The pawl is a spring strip attached to the standard with the upper engaging end of the strip being the pawl in the form of a downwardly facing tooth or lug for engaging with the upwardly facing base of the ratchet teeth. The pawl is adapted with both engaging teeth and locking lugs in one unified structure and is utilized on only one vertical support surface of the standard.  
           [0014]    On Jan. 19, 1943 U.S. Pat. No. 2,308,714 was granted to Ralston for an adjustable chair. It is noteworthy here because of its two vertical spaced apart support standards each of which employs a pawl and ratchet mechanism linked together via a single rod and lever mechanism for lowering and raising the chair using a pair of spring connected pawls for alternately engaging opposing rows of ratchets at each standard supporting the chair.  
           [0015]    On Jul. 4, 1944 Parham was granted U.S. Pat. No. 2,353,064 for a beauty parlor stand wherein the improvement consisted of an adjustable single pedestal table top whereby implements placed thereon are all moved in closer proximity to a patron to save operator time.  
           [0016]    On Dec. 19, 1967 U.S. Pat. No. 3,358,620 was granted to Italian inventor P. Parigi for a single tilted standard supporting a ratcheted and spring rotatable loaded worktable adapted as a drawing board.  
         OBJECTS OF THE INVENTION  
         [0017]    It is a main object of the present invention to provide a heavy duty workbench capable of supporting work several times its weight at selected heights and further capable of moving and adjusting the work surface of the workbench up or down in small equal increments using a foot actuator improved with an interconnecting spring structure to avoid accidental disengagement.  
           [0018]    It is another object of the present invention to provide a workbench having a height adjustable work surface using at least two manual and independent height adjustable standards.  
           [0019]    It is yet another object of the present invention to provide a workbench with a height adjustable work surface, which can be tilted at both ends.  
           [0020]    It is still another object of the present invention to provide a workbench wherein each standard is made of a pair of nesting inner and outer frames which together support one end of a workbench.  
           [0021]    It is an object of the invention to provide a workbench wherein an inner support frame is locked at variably selected heights using a rounded pawl that disengageably engages one of a mating set of rounded ratchets.  
           [0022]    It is another object of the invention to provide an adjustable height workbench top which is actuated using a foot pedal to generate a rotation of a rod, the rod being attached to the top and oriented parallel to the top, the rod acting as a pawl wherein the rod dually and simultaneously engages and/or disengages from a mating rounded ratchet arrayed in a vertical set of ratchets forming a part of two supporting standards.  
         SUMMARY OF THE INVENTION  
         [0023]    One problem with the workbench structures of the prior art is that a structurally rigid heavy duty bench with an adjustable height top adapted to support several times the weight of the bench wherein the top is dually engaged by a single pawl-like structure has been heretofore unavailable. The pawl and ratchet mechanisms rely on individual pawls in each standard. These separated pawls do not structurally brace the workbench from one side to the other or provide integral support, relying instead on the top itself and separate bracing structures connected between the standards.  
           [0024]    In the novel invention there is a vertical set of rounded ratchet slots or apertures which are engaged by a rod-like structure which extends from one edge of a standard to the other edge and which simultaneously engages the ratchet slots at the same height on each edge of the standard. In addition, a novel safety mechanism was discovered, designed and integrated into the workbench. This safety mechanism is a combination of a tension spring connected between a chain and a foot actuator pedal. It was discovered that this spring prevents accidental release of the rod by absorbing unintentional minor force applied to the pedal. Early prototypes would sometimes be inadvertently disengaged. Thus, the safety mechanism was incorporated into the novel workbench to prevent accidental disengagement from the supporting ratchet. Further, it was discovered that the rod-like structure (pawl) provides the best structural rigidity for the bench when rotated into the ratchet slots at an angle between less than 45 degrees and greater than about 10 degrees. Moreover, it was also discovered that when the rod-like pawl is combined with the mating round ratchet slots, wear is lessened compared to angulated ratchet slots or where a ledge or flat surface is formed on the rod as a point of engagement contact.  
           [0025]    The rigidity of the bench and each standard is also improved by means of a novel locking action. This locking action or mechanism is a shim extension attached to a brace used at each side of the standard between an inner ratchet frame attached to the top of the bench and an outer frame, which rests on the floor. The shim extends between the back of the inner frame and the inner surface of the outer frame and presses and locks the ratchets on the inner frame against the ratchet engaging rod at each side of the inner frame. The angle formed by the line connecting the engaging rod axis and the rotating rod axis and horizontal is between about 10 degrees and 45 degrees. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0026]    The above objects and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings wherein:  
         [0027]    [0027]FIG. 1 illustrates both a right end view and a left end view of the novel workbench showing the parts of a standard braced with attached side rails and a top with a ratcheted support member;  
         [0028]    [0028]FIG. 2 illustrates both an assembled right standard and an identical assembled left standard;  
         [0029]    [0029]FIG. 3 is a top view of the standard shown in FIG. 2;  
         [0030]    [0030]FIG. 4 is an exploded perspective view of the parts of the standard illustrated in FIG. 2;  
         [0031]    [0031]FIG. 5 is a front view of a complete assembly of the novel workbench showing a bracing member connected between the standards; and,  
         [0032]    [0032]FIG. 6 is a cut-away magnified detailed view of the rod and ratchet assembly and piano wire spring and shim in each standard. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0033]    In FIG. 1 there is shown a view of the identical left and right sides of a novel workbench  10 . There is also shown one of two adjustable height supports, for example a left standard  12  shown in accordance with the novel invention. A right standard  13  (shown in FIG. 5) supports the top of the workbench  31 . The standard  13  is a replica of the standard  12 . The standard  13  bears the same like-numbered parts as the standard  12  detailed in FIG. 1.  
         [0034]    As shown in FIGS. 1, 2 and  4  the standard  12  has outer vertical frame  14  with a bracket-shaped ([) cross-sectional plan view and an inner vertical frame  16  with a congruent bracket-shaped ([) cross-sectional plan view. The vertical frame  14  is made of steel or aluminum, for example, having a thickness of ⅜ th  of an inch, for example. The vertical frame  14  has vertical edges  18  and  19 . The inner vertical frame  16  has a right vertical panel  46  and a left vertical panel  48 , each bearing equally spaced apart ratchets or sets of ratchet apertures  21  and  22  with teeth  24  wherein the apertures  21  and  22 , and teeth  24  alternate to form an assembly of ratchets. The frame  16  is slidingly spaced and nested within the outer frame  14  by first and second spacers  26  and  28 .  
         [0035]    Referring to FIG. 3 there is a plan view which shows the spacers  26  and  28  are right angular solid pieces. In FIG. 4 further detail of the spacers  26  and  28  illustrates the spacers  26  and  28  are made of solid rectangular parts  26   a  and  28   a , respectively, connected at right angles to relatively thin rectangular shims  26   b  and  28   b , respectively.  
         [0036]    The relatively thin rectangular shims  26   b  and  28   b  extend behind the inner frame  16  and between frames  14  and  16 . The parts  26   a  and  28   a  are attached at a right narrow vertical sidewall  30   a  and a left narrow vertical sidewall  30   b , respectively, which are parts of the outer bracket-shaped frame  14 . As further shown in FIG. 4, the outer bracket-shaped frame  14  is made up of a vertical back wall  30   c  interconnecting the left narrow vertical side wall  30   b  and the right narrow vertical side wall  30   a.    
         [0037]    Shown in FIG. 1 is a top  31  attached to the standard  12  with bolts  32 , for example. A front bracing rail  34  (or lateral front brace) and a back bracing rail  36  (or lateral back brace) are attached to the standard with bolts  38 , for example.  
         [0038]    Shown in FIG. 1, the inner frame  16  is indirectly supported by a horizontal rod  40  extending through the narrow vertical walls  30   a  and  30   b  of the outer frame  14 . Actual direct support is provided by allowing the inner frame  16  to rest on the rod, which forms a pawl member  42 . The pawl member  42  retractably rotatingly engages the two sets of ratchet apertures  21  and  22  at parallel positions. The pawl member  42  or rod retractably rotatingly engages the first ratchet aperture  21  located on an edge of the inner frame  16 . The pawl member  42  or rod also retractably rotatingly engages the other corresponding ratchet aperture  22  located on another edge of the inner frame  16  at a corresponding parallel position.  
         [0039]    Referring to FIG. 4, the inner frame  16  is formed by a rear vertical panel  44  connecting the right vertical panel  46  to the left vertical panel  48 . The set of ratchet apertures  22  are located on the edge of the right vertical panel  46 . The set of ratchet apertures  21  are located on the edge of the left vertical panel  48 .  
         [0040]    The pawl member  42  is a rod somewhat smaller in diameter than the rod  40  as illustrated in FIG. 2. Referring to FIG. 4, the pawl member  42  is affixed lengthwise to the horizontal rod  40  with threaded screws  41  and  43  extending transversely through and across the axis of the pawl member  42  and further extending threadedly into the horizontal rod  40 .  
         [0041]    Fully shown in FIG. 4 is a novel rotational biasing means for causing the pawl member  42  combined with the horizontal rod  40  in the manner shown to rotate about the axis of the rod  40  toward the ratchets  21  and  22 . The pawl member  42 , i.e. a rod, is engaged by teeth  24  (FIG. 1) and thereby retained with the assistance of a force applied by the piano wire  50  fixedly engaged between the rod  40  and the pawl member  42  by a threaded screw  43 , for example, centrally located in the pawl member  42 .  
         [0042]    The rotational biasing means comprises a wire  50 , namely, a length of rigid high tensile strength wire such as large gauge piano, for example. As illustrated in FIGS. 1 and 2, the piano wire  50  has a bend at its center point about the screw  43 . The piano wire  50  has one end rigidly fixed in an aperture in the wall  30   b  and the other end rigidly fixed in an aperture in the wall  30   a . The piano wire  50  is twisted or bent toward the inner frame  16  as a part of a means for pressing and locking the pawl member  42  into a selected ratchet at a selected height in the set of ratchets  21  and into a corresponding ratchet at the same height in the set of ratchets  22 .  
         [0043]    In FIG. 4 is shown a novel safety mechanism comprising a foot pedal  60 , chain  62 , and spring  64  connected as shown with one mechanism incorporated into each of the standards  12  (FIG. 2) and  13 . Two of these safety mechanisms are used conjunctively to prevent inadvertent removal of the ratchet support for the workbench top  31  (FIG. 1). The safety mechanism is connected to the rod  40 . The mechanism connects via a screw  66  (FIG. 1) fixedly threaded into the side of the rod  40  and extending through a link of the chain  62 , which interconnects the screw  66  to a top end of the spring  64 . Shown in FIG. 204, another length of the chain  62  interconnects a bottom of the spring  64  to a screw in the foot pedal  60 .  
         [0044]    A side view of the novel bench  10  with left and right standards  12  and  13  supporting the top  31  is shown in FIG. 5. There is shown the lateral front brace or rail  34  bolted to left and right standards  12  and  13 . Foot pedals  60  are shown extending from the standards  12  and  13 .  
         [0045]    A detailed view of the end structure inside the standard  14  is shown in FIG. 6. An end of the rod  40  is shown with its center A aligned with a lateral point C on the standard  14 . An end of the rod forming the pawl member  42  is shown having a round cross-section and a center B. The rod  40  is separated and spaced away from the pawl member  42  by two parts of the wire  50  bent between them.  
         [0046]    Shown in FIG. 4, the wire  50  is bent and extended around the screw  43 . The screw  43  and screws  41  extend through the pawl member  42  and into the rod  40  firmly holding the wire  50 . In FIG. 6, a line A-B and a line A-C form an angle α representing the angular rotation of the center of the pawl member  42  from a horizontal plane through which extends the line A-C. Shown also is the ratchet assembly comprised of the apertures  21  and teeth  24  (FIG. 4). The apertures  21  are formed of a curved rounded edge  70  in the inner frame  16  (FIG. 6). The edge  70  is formed and sized to matingly receive the rounded surface of the pawl member  42 .  
         [0047]    The height of the workbench  10  is raised by pulling up the inner vertical frame  16 . As the frame  16  is raised the pawl member  42  is rotated out of one of the apertures  21 . To lower the workbench  10 , when the foot pedals  60  shown in FIG. 5 are sufficiently depressed the top of the workbench is raised slightly simultaneously to allow the pawl member  42  to disengage from the vertical frame  16 . The frame  16  revolves about the rod  40  into another one of the apertures  21  by a spring action of the piano wire  50  whereby the angle α is preferably between less than about 45 degrees and greater than about 10 degrees. When the angle a is maintained in this range the inventor has determined that this provides the greatest support and ease of disengagement and re-engagement of the pawl member  42 . One way the angle α is set to within this range is by selecting or adjusting the thickness of the member  28   b  used to separate the back of the vertical frame  16  from the outer vertical frame  14 .  
         [0048]    It will be apparent to those skilled in the art that various changes may be made to the embodiment presented herein by using equivalent mechanical means without departing from the scope of the invention; and therefore, the invention is not to be limited to what is described in the specification and shown in the drawings, but only as indicated in the appended claims and their equivalents in accordance with the doctrine of equivalents.  
       Parts List  
       [0049]    Workbench  10   
         [0050]    left standard  12   
         [0051]    right standard  13   
         [0052]    outer vertical frame  14   
         [0053]    inner vertical frame  16   
         [0054]    left vertical edge  18   
         [0055]    right vertical edge  19   
         [0056]    ratchet apertures  21   
         [0057]    teeth  24   
         [0058]    ratchet apertures  22   
         [0059]    first spacer  26   
         [0060]    second spacer  28   
         [0061]    solid rectangular part  26   a    
         [0062]    solid rectangular part  28   a    
         [0063]    thin rectangular shim  26   b    
         [0064]    thin rectangular shim  28   b    
         [0065]    right narrow vertical sidewall  30   a    
         [0066]    left narrow vertical sidewall  30   b    
         [0067]    vertical back wall  30   c    
         [0068]    top  31   
         [0069]    bolts  32   
         [0070]    front bracing rail  34   
         [0071]    back bracing rail  36   
         [0072]    standard bolts  38   
         [0073]    horizontal rod  40   
         [0074]    threaded screws  41   
         [0075]    pawl member  42   
         [0076]    threaded screw  43   
         [0077]    rear vertical panel  44   
         [0078]    right vertical panel  46   
         [0079]    left vertical panel  48   
         [0080]    piano wire  50   
         [0081]    foot pedals  60   
         [0082]    chain  62   
         [0083]    spring  64   
         [0084]    screw  66   
         [0085]    rounded edge  70   
         [0086]    center A  
         [0087]    point C  
         [0088]    center B  
         [0089]    line A-B  
         [0090]    line A-C  
         [0091]    angle α