Abstract:
The disclosed portable sawhorse has a collapsible base formed of two side panels pivoted together, with a top rail having spaced end legs telescopically connected at U-shaped holders to one of the side panels for top rail movement between varied vertical spacings above the base. A latch pivoted to each holder is shifted between a position engaging the end leg for holding the top rail at selected spacings above the base and other positions allowing top rail movement. In the engaging position, the latch bottoms against the end leg with forces proportional to the top rail loads. Extenders carried on the top rail can be shifted to change effective top rail lengths. The side panel not carrying the top rail holders has upper edges that engage the top rail end legs operable to directly transmit via this side panel part of the top rail load.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     Sawhorses are commercially available, purchased and used in part because they are lightweight, collapsible, and relatively inexpensive, while yet being highly effective to provide for constructing a platform or support between operating pairs of sawhorses. Simplifying the component parts and the manner and effort needed for their assembly also has reduced the cost of sawhorses, helping this trend of acceptance and use.  
         [0002]     My U.S. Pat. No. 6,422,343 B1, issued Jul. 23, 2002, disclosed a COLLAPSIBLE SAWHORSE that had many related features and advantages, and its teachings are to be incorporated herein for disclosure of structures possibly not fully illustrated herein.  
         [0003]     Following this concept, adding the features for adjusting the load supporting top rail, in so far as its height above the supporting surface and/or its horizontal length, would offer even further user appeal.  
       SUMMARY OF THE INVENTION  
       [0004]     This invention relates to and an object of this invention is to provide an improved collapsible sawhorse, having separate components that are economically injection molded and rapidly and easily assembled, while further having the features that the load supporting top rail can be adjusted, both in its height above the supporting surface and/or in its horizontal length. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0005]     This and other objects, features or advantages of this invention will be more fully understood and appreciated after consideration of the following description of the invention, which includes the accompanying drawings, wherein:  
         [0006]      FIG. 1  is a top plan view of the improved sawhorse, shown in an opened operative condition;  
         [0007]      FIG. 2  is a front elevational view of the  FIG. 1  sawhorse;  
         [0008]      FIG. 3  is an end elevational view of the  FIG. 2  sawhorse;  
         [0009]      FIG. 4  is an end elevational view similar to  FIG. 3 , except showing the sawhorse in its closed condition;  
         [0010]      FIG. 5  is an end elevational view similar to  FIG. 3 , except showing the sawhorse with its top rail in an elevated position;  
         [0011]      FIG. 6  is an exploded perspective view of major components making up the sawhorse of the previous figures;  
         [0012]      FIG. 7  is perspective view of a pocket or holder used for supporting the top rail side bar;  
         [0013]      FIG. 8  is a perspective view of a portion of the opened sawhorse, showing a height adjustment latch disengaged from the top rail side bar;  
         [0014]      FIG. 9  is a perspective view similar to  FIG. 8 , except having the one side panel, that holds the illustrated top rail side leg and latch mechanism, eliminated and showing also the hidden side of the other side panel;  
         [0015]      FIG. 10  is a view from the underside of the top rail, showing linkage for moving the extender bars symmetrically between different closed and expanded positions;  
         [0016]      FIG. 11  is a sectional view as seen generally from line  11 - 11  in  FIG. 10 ;  
         [0017]      FIG. 12  is a sectional view of the top rail latch shown in the engaged locking position with the side bar;  
         [0018]      FIG. 13  is a sectional view of supplemental support mechanism operable between the side panel not carrying the top rail and the top rail end leg, for distributing a top rail load between the two connected side panels; and  
         [0019]      FIG. 14  is a perspective view of a clip used for forming the support mechanism of  FIG. 13 . 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0020]     The illustrated sawhorse has a base  10  and an overlying workpiece carrying top rail  12 . The top rail  12  is moveable between a lowered position illustrated in  FIGS. 1-4 , and raised positions as illustrated in  FIGS. 5, 13 . This provides that an object supported on the top rail  12  can be adjusted to different heights above the underlying supporting ground or floor. Further, extender bars or wings  14  (see  FIGS. 6, 12 ) are mounted on the top rail  12 , moveable axially of the top rail between a retraced position of  FIG. 2  and adjusted extended positions that provide different sawhorse support widths.  
         [0021]     The base  10  is comprised of two identical side panels  16 ,  17  and a utility tray  18  comprised of two identical panels  20 . Each base panel  16 ,  17  can have two upstanding legs  22  and upper and lower cross beams  23 ,  24  extended between the legs. The legs  22  and cross beams  23 ,  24  have a common generally flat front wall  26 , and substantially continuous flanges  28 ,  30  perpendicularly angled rearwardly away from the inner and outer front wall edges and terminating along a generally planar rear edge  32  generally parallel to the front wall  26 .  
         [0022]     The two base side panels  16 ,  17  are hinged together proximate the respective upper cross beams  23 , to pivot about generally horizontal axis  33  ( FIGS. 8, 9 ,  13 ). The two tray panels  20  are hinged together along medial edges  34  and are hinged at the outward edges  36  onto the lower cross portions  24 . This allows the base  10  to be shifted between the illustrated opened position for stable sawhorse support on a generally flat horizontal support surface and the collapsed condition ( FIG. 4 ). The tray panels  20  can be pulled upwardly at the medial hinged edges  34  via hand hole  37 , which draws the side panels  16 ,  17  together, so that the side and tray panels then lie generally parallel and side by side. The tray at the hole  37  can further be gripped for carrying the closed sawhorse with one hand.  
         [0023]     The above hinging connections at axis  33  can be achieved in part according to my above mentioned U.S. Pat. No. 6,422,343 B1. Thus, cylindrically curved open-sided hooks  38  ( FIG. 6 ) can be aligned along part of each panel and shafts  39  can be aligned along its remainder, with the hooks and shafts being coaxial and properly spaced apart laterally and symmetrically from the panel center so that when the side and the tray panels are rotated to face one another, the hooks and shafts can be interlocked together pivotally. Segmented end pins  40  ( FIGS. 8, 9 ) projected coaxially along axis  33  can be held together by a slip ring (not shown) fitted over the pins, to hold the panel edges together.  
         [0024]     Each side panel  16 ,  17  can be reinforced by crossing webs  42  ( FIG. 9 ) integrally projected from the hidden side of the front wall  26  and peripheral flanges  28 ,  30  and each other, as by injection molding the side panels of plastic.  
         [0025]     The top rail  12  ( FIG. 6 ) is comprised in part of rigid generally parallel end bars or legs  43  and a cross bar  44  extended therebetween. The end legs  43  preferably have a generally rectangular cross-section, with a flat exposed front wall  45 , side flanges  46  rearwardly projected therefrom, and reinforcing crossing rear webs  47  integral with the front wall and flanges. Each leg front wall  45  has a number of openings  49  therein uniformly spaced apart along its length, much in the manner of cross rungs on a ladder.  
         [0026]     Mounting structures cooperate between the end legs  22  of the base side panel  16  and the top rail end legs  43 , operable to hold the top rail  12  laterally stable while allowing it to be telescopically adjusted between different vertical spacings above the base  10  and/or the horizontal surface. The mounting structure is formed by eliminating any reinforcing webs  42  in the side panel legs  22  between interior walls  52 ,  53  projected from the front wall  26 ; and by securing a U-shaped pocket or holder  54  ( FIG. 7 )to the front wall  26  between these one side panel walls.  
         [0027]     Each pocket or holder  54  has a rear wall  55  and spaced flanged side walls  56 , and can be secured from the rear side of the end legs by positioning stepped holder openings  57  snuggly over end leg rear bosses  58  ( FIGS. 8, 9 ), and by tightening headed screws (not shown) stopped at the smaller of the stepped openings  57  and threaded into taps in the leg bosses  58 . Added holder stability can be achieved by fitting locator ribs  59  (aligned with but oppositely extended from rib  59 A visible in  FIG. 7 ) snuggly into small cutouts off of side panel front wall opening  60 . The side panel outer flange  30  is cut away as at  61  ( FIG. 6 ) to receive each top rail end leg  43  (or a support clip  95  ( FIGS. 14, 15 ) to be discussed later.  
         [0028]     The side panel walls  53  and holder side walls  56  can be lined up, and these and the rear side of the panel wall  26  and the front side of the holder wall  55  can be spaced apart to receive with minimal clearance the top rail end legs  43 .  
         [0029]     Each holder  54  has laterally spaced ears  64  that will, when the holder is secured to the side panel, project through the front wall opening  60  and forwardly from the front wall  26 . A latch  65  is pivoted to the ears by a pin  66  fitted through a latch opening and through aligned ear openings  67 . The pin  66  can be comprised of two separate headed pieces inserted from the outward sides of the ears  64  to cause meshing barbs or the like (not shown) to become interlocked within the latch opening. The side panel  17  not carrying the top rail  12  can have separate pieces  68  snapped onto the front wall to cover the opening  60 .  
         [0030]     Each latch  65  further has a radially extended lug  70  that upon latch rotation can be butted against the top rail end leg front wall  45 , and fitted into any opening  49  therein when properly aligned therewith. The latch pivot pin  66  is forwardly spaced from the lug engagement with the end leg  43 , so that downward end leg movement rotates the latch (clockwise in  FIG. 12 ) until its free end  73  bottoms against the end leg. The bottomed latch structurally prohibits further downward top rail movement, and the latch lug  70  is then engaged against the upper edge of the opening  49 .  
         [0031]     However, when a user attempts to move the sawhorse (with no load on it) by lifting it from the top rail, the upward end leg movement and accompanying lug engagement shift against the lower opening edge could rotate the latch to disengage it, thereby allowing the set top rail height adjustment to be changed.  
         [0032]     To prevent this latch disengagement, retainer pins  75  ( FIGS. 8, 9 ,  12 ) are axially extended off of the latch  65  operable to fit, when the latch is in the locking position, within curved slots  76  in the holder ears  64 . Some vertical clearance will be provided also between the lug and the upper and lower edges of the end leg openings  49  when in the locking position. As such, the pins  75  will bottom against the ear at slots  76 , before the lug can be shifted to engage against the lower side leg opening edge. The pins  75  need be structural enough only to carry the sawhorse weight when the sawhorse is lifted by the top rail. When the lifting force is removed from the top rail and a downward top rail load prevails, the latch lug  70  will again engage the upper opening edge and the latch pins  75  will loosely fit in the ear slots  76 .  
         [0033]     The top rail  12 , in addition to the elongated extenders  14  and cross bar  44 , is comprised of an open-ended inverted “U” shaped cap  78  that is locked onto the cross bar for generally enclosing the rail extenders. Specifically, cap top wall  81  and side walls  82  angled therefrom, respectively define generally parallel inner faces, which with the parallel upper face of the cross bar  44  laterally contain the extenders  14  while allowing them to move axially into and out of the open cap ends. The lower portions of the cap side walls  82  form generally parallel alternately arranged upper and lower lips  85  suited to receive therebetween the opposite side edges of the cross bar  44 , for mechanically connecting the cap and cross bar together. The united association of the components  14 ,  44 ,  78  provide the needed top rail beam strength.  
         [0034]     A projection  86  ( FIG. 11 ) laterally wider than the lower lips but narrower than the side wall connecting the lips together, can be located to fit between the lower lips when the cap is properly placed on the cross bar. This can firmly secure the cap against unwanted movement along the cross bar  44 .  
         [0035]     The top rail extenders  14  ( FIGS. 6, 7 ,  10 ,  11 ) have one end configured as a toothed rack  87  that can simultaneously engage opposite sides of a pinion  88  rotated on a post  89  projected from the cap top wall  81 . This correlates the extending and retracting extender movements symmetrically centered on the top rail. Enlarged heads  90  on the extenders engage the opposite cap ends with the extenders fully retracted, and stops  91  on the innermost rack ends engage the pinion  88  with the extenders fully extended. Each extender  14  spaced endwardly from the rack has two different cross sections, outer sections  93  sized to fit slidably between the confining cap side wall  82  during part of the extender movements and intermediate section  94  sized to fit with the adjacent rack slidably between the confining cap side walls during all of the extender movements. Axially extended guides (not shown) formed off of the cap top wall can engage the intermediate cap section  94  when the outer sections  93  are withdrawn from the surrounding confines of the cap.  
         [0036]     Although the four side panel legs  22  provide stable sawhorse support during use, the telescopic supports provided between the holders  54  and the top rail end legs  43  seem to drive a larger percent of the top rail load axially of that side panel  16 ; while the other side panel  17  can serve merely to prop up that holder bearing side panel  16  via the connection between the side panels at pivot  33 . On the other hand, as the raised top rail  12  is laterally shifted off center of the pivot  33  and the base  10 , to overlie the side panel  17  more than the holder carrying side panel  16  due to the converging inclination each side panel has at the common pivot  33 , the side panel  17  possibly can end up carrying a greater percent of the top rail load. These conflicting factors and possible causes for load imbalances can be neutralized to a great extend by the following structures.  
         [0037]     Thus, clips  95  ( FIGS. 13, 14 ) are secured onto the upper ends of the side panel  17  at the flange cutouts  61 , suited to fit into horizontally aligned notches  96  formed in the rear sides of the two top rail end legs  43 . The notches  96  can be formed by removing the forward portions of some of the reinforcing webs  47 . The notches  96  and latch openings  71  in the end legs  43  will be provided at the same spacings along the end legs, so that when the latch lug  70  is fitted into one opening the clip will be fitted into a corresponding notch.  
         [0038]     As proposed, the clips  95  will engage the top rail end legs  43  vertically spaced above and laterally offset from the pivot axis  33 . These clip engagements against the rear sides of the end legs  43  can redistribute the top rail load beneficially between the side panels  16 ,  17 , as part of the top rail load from the engagements is directly applied to the side panel  17 , and these clip-side panel engagement locations more directly underlie the top rail  12  and are closer to the side panel  17  than to the holder carrying side panel  16 .  
         [0039]     Specifically, the clip  95  can have a top wall  97  and spaced rear and front legs  98 ,  99  depending from the top wall suited to straddle and fit over the front wall  26  of the side panel  17 . The top wall  97  is extended rearwardly away from the side panel wall  26  in the form of a ledge operable to fit into the rear notch  96  on the top rail end leg. The ledge width can be slightly less than the spacing between the flanges  46  of the end legs. While the rear clip leg  98  can be the same width as the illustrated ledge width, spacer pins  100  beneficially can be formed off of the side edges to provide an overall width just shy of hitting the flanges  28 ,  30  of the side panel  16 , for quick and easy clip centering within the cutout  61 . The rear leg  98  can have an outwardly directed lower lip  101  suited to fit into the front wall opening  60  of the side panel  17 , for underlying and engaging the upper opening edge and stabilizing and securing the clip supported on the side panel. For appearance reasons primarily, the front leg  99  can be made the same width as the latch  65 .  
         [0040]     The clip top wall ledge  97  will engage the side panel  16  at the notch  96  when the sawhorse is operatively opened and positioned on a support surface, while it will become spaced and separated therefrom when the sawhorse is closed ( FIG. 4 ).  
         [0041]     While a specific sawhorse embodiment has been illustrated, minor changes could be made without departing from the overall spirit of the inventive teaching. Accordingly, the invention is to limited only by the scope of the following claims.