CA1057807A - Workbench and foldable leg assembly therefor - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
An improved foldable leg assembly for dual-height workbenches and like devices which is simple to construct, requires no foldable braces or stays, employs an extremely simple hinge plate structure to connect same to a workbench base, the legs being oriented and arranged to provide adequate stability in the higher position of the workbench. The dual height workbench .
includes top members defining a working surface, a base defining ...
longitudinal and transverse axes and support structure for supporting said top members above said base. A plurality of leg members are pivotally attached to said base adjacent outer edge portions of same and movable between inwardly folded inoperative positions corresponding to the lower height of the workbench and outwardly and downwardly inclined operative positions relative to said base corresponding to the higher position of the workbench. The pivotal attachment of the respective legs is such that each of said legs is capable of movement in an arc lying in a plane which is at an acute angle relative to the longitudinal and transverse axes of said base. Each said leg includes at its upper end pivot axis de-fining means, with a portion of said upper end spaced from said pivot axis defining means being shaped to transmit thrust forces to said base and to limit the degree of outward pivotal motion of said leg thus to define the outwardly and downwardly inclined operative position of each leg.

Description

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This is a divisional application of Canadian Patent Application 209,110 filed September 12, 1974.
This invention relates to a foldable leg assembly specially adapted for use with workbenches and other heavy duty applications where strength, stability, ease of access and simplicity of construction are of primary importanca.
The invention is particularly adapted for use in workbenches and the like wherein a dual height working surface is desired and, accordi~gly utilizes pivotally mounted :Legs movable from a folded inoperative position corresponding to the lower of the two positions to an unfolded opera~ing posi-tion corresponding to the higher of the two positions.
One form of workbench for which the present invention is particularly suited is described in U.S. Patent No. 3,615,087 issued Oct. 26, 1971 to R.P. Hickman. This patent describes a workbench including a support structure bearing a pair of top members lying in a plane and defining a working surface with at least one of the top members being movable towards and away from the other upon actuation of a pair of spaced independently operable clamping devices to vary the gap between the top ~
members and parmit the clamping of a wide variety of work ` `
pieces relative to the work surface. The support structure in-cludes a rectangulax base and a frame assembly extending between the base and the top members. The frame assembly includes a pair of frame members pivotally connected in such fashion as to permit movement between an erected working posi~
tion wherein the top members are spaced above the base and a collapsed position in which the top memhers are in d ose juxta~
position to the base.
3~ In order to provide a dual height working surface for the above not~d structure, there has hitherto been provided a foldable leg structure for securement to the base member. Such r ~ 7~

leg structure included a leg pivotally connected at each o~ the four corners of the rectangular base in such manner that, when folded, the legs moved into general alignment with the opposed ends of the base. In order to support the legs in the unfolded or erected position, foldable braces or struts were employed.
However, such foldable braces, in addition to making the structure somewhat more complicated, made the structure more difficult ~o manipulate; furthermore, the braces, Ln their erectea positions, were apt to interfere with the user's feet and thus affect the user's forward access to the workbenc~.
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There is also the problem of stability to be con-sidered. In the higher of the two positions of the workbench there is the requirement that the support legs be oriented such that increased resistance to tipping of the workbench is pro-vided. Good stability is an extremely important requirement 1 particularly when it is considered tha*, in workbenches of the ;
type discussed above, the user often sits upon a portion of the '~
working surface of the workbench, depending on the nature of the work being done, and thus is apt to be injured if the work- '``
bench topples over.
With further reference to typical prior art structures, it is noted that variol~s types of folding leg struct~res have been provided on lightweight card tables and portable picnic ;
tables. However, in general, it may be said that these 11~ .
structures are not suitable for heavy duty use in workbenches or the like since the overall design of the pivot bracket in most of these structures is unduly complex and thus overly costly to produce particularly in applications where high strength is required. In addition, the design of the legs, par ~`
se, is usually inadequate for applications where relativa~y large forces and bending moments may be involved.

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7~7 Thus, in accordance with the present invention in :
one aspect there is provided a dual elevation workbench or the like compris~ng: bench top means for deining a working surface; a base defining a rectangu1ar outline; support structure for supporting said bench top means above said base;
a plurality of legs; and hinge pivot means for pivotally attaching said legs ~o said base respectively, each of said legs being pivotally attached to said base so as to be pivotally movable between respective inwardly folded inoperative positions corresponding to the ~ower elevation of the work-bench a~d respective outwardly and downwardly inclined opera tive positions relative to said base correspondlng to the higher elevation of the workbench, said legs being pivotally attached to said base by said respective hinge means so as to cause said legs in said operative positions to extend outwardly in respective directions defined substantially by the diagonals of said rectangular outline and away from said rectangular : -base in splayed fashion to locations on the floor outside of and beyond a plan projection of said bench top means and said .~
base on the floor whereby the workbench will remain in static .
eq~ilibrium irrespective of where a load is applied to said working surface and said base. ~ ;~
In accordance with the invention in a further aspect ~:
there is provided a dual elevation workbench or the like comprising: bench top means for defining a working surface; a -base; support structure for supporting said bench top means above said base; a plurality of legs; and hinge pivot means corresponding to respPctive ones of said legs for pivotally attachiny said legs to said base adjacent outer edge portions thereof so as to be pi~otally movable between respective out-wardl~ and downwardly inclined operative posi~ions correspond-ing to the lower elevation of the workbench and respective 1 , outwardly and downwardly inclined operative posit1ons correspond-ing to the higher elevation of the workbench, the pivotal attachment of the respective le~s heing sucb that in said operative positions said legs extend outwardly away from said base in splayed fashion to locations on the. floor outside of and beyond a plan projection of said bench top means on the ~:
floor, each of said legs having structure means engaging said base outboard of said corresponding hinge pivot means for coacting with said hinge pivot means to transmit thrust forces developed by loads applied to said working surface from said 1 ~;
base to said floor locations whereby the workbench will remain in static equilibrium irrespective of where a load is applied .~ ~ .
to said working surface O
In the preferred form of the invention, said base `:
is of rectangular outline and the legs extend outwardly in respective directions defined substantially by the diagpnals of the rectangular outline. Further, in the preferred form of the invention, the legs ar~ of a one-piece, triangular-like structure having a three sided triangle-like upper end and tapering to an apex at the foot of the leg with the upper end of the leg being further shaped to co-operate with the . .:. .
base to define the outwardly splayed operative position of the leg.
In a typical embodiment of the invention, said base is provided with a plurality of suppor~ feet for contacting a floor surface in the lower position of the workbench, each support 1:
foot being located ad]acent a respective one of said legs, and each said leg having a recess ox opening therein for receiving : :
a portion of the associated support foot therein in the operative position of such leg whereby to avoid interference between each leg and the adjacent support foot of the base. ~ ~:
A3 a still further feature of the invention, each .
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of the legs may he provided with a respective floor contacting means with the legs being shaped such that when the legs are in their operative positions, their floox contacting means are disposed a substantial distance outwardly beyond the margins ; of the base, as seen in plan view, to provide added stabllity -to the workbench in the higher position of same.
The invention, in all its many aspects, is par- ~
ticularly well suited for workbench structures wherein thP ~ :
support structure for supporting the top members above the base has pivot means associated therewith to permit the workbench ~ ;
to be collapsed and the top members brought into juxtaposition ~ -~
with the base for ease of transport and storage of the workbench.
Additional important features of the invention may ~
be had from the claims appended hereto. .
The invention will be further understood from th~
following aescription of the preferred embodiment of same i with reference being had to the accompanying drawings, in :
which: .
Figure 1 is a perspective view of a workbench :.
incorporating the principles of ~he invention with the pivotally . `
mounted legs being shown folded to inwardly located inoperative positions. .-- Figure 2 is a perspective view of the workbench with the legs shown in their outwardly and-downwardly inclined opera-tive positions relative to the workbench base.
Figure 3 is a bottom view of the workbench in a ~ s~
collapsed position with the legs folded inwardly.
Figure 4 is a perspective view of one of the legs shown from the underside in the open position.
Figures 5 and 6 are side and end elevation Yiews respectively of the workbench in its operative position, the ~ ;
legs being in their outwardly and downwardl'y inclined oparative -locations relative to the base.
Figure 7 is a fragmentary side elevation view showing ~ -a portion of the base and the leg and hinge plate structure.
Figure 8 is a side elevation view of the top portion ~ `~
of the leg illustrating the hinge pin receiving means. ~
Figure 9 is a bottom view o~ the upper end of the leg ~ ;
in combination with the hinge plate and spring clip assembly for retaining the leg in either the operative or inoperative posi- -tion.
Figure 10 is a view similar to Figure 7, but with a `
portion of the upper end of the leg being cut away to show the manner in which the leg cooperates with the spring clip ~or retention of the leg in operative and inoperative positions.
Figure 11 is a top plan view of one of the legs.
Figure 12 is an end elevation view of the leg structure shown in Figure 11 illustrating the crimped cross-sectional configuration of same.
Figure 13 is a section view taken along line 13-13 of Figure 11. ;~
With reference now to the drawings, particularly Figures 1, 2, 5 and 6, there is shown a dual height workbench 10 including a pair of relatively movable top members 12 defining a working surface. The woxkbench also includes a skeleton or outline type base of generally rectangular configuration and identified by the reference numeral 14. m e workbench also includes a ~upport structure broadly indicated by the reference ¦~

105~7 ` ~
numeral 16 for supportillg top members 12 ahovP the base 14.
As described more ully in U.S. Patent 3,615,087 issued October 26, 1971 to Hickman, the support structure 16 includes a pair of spaced apart generally H shaped frames 18 pivotally connected to the base member 14 at points 20 and pivotally connected to the top ~ember support structure 22 at points 24. By virtue of this arrangement, the workbench may go from the worklng positions as shown in Figures 1, 2, !; and 6 to a collapsed storage position in which the top members 12 are in close juxtaposition to the base 14. Side mounted lock bars 26 serve to retain the workbench in the working position. ~ ' In addition t the top support structure 22, upon which the top members 12 are mounted, includes means permitting one of ;
the top members, e.g. top member 12a, to be moved towards and ;
away from the other top member to permit workpieces and other objects to be clamped between the top members 12. This feature forms no part of the present invention and is fully described -in the above noted U.S. Patent 3,615,087. It is sufficient to note here that the top support structure has mounted therein :
screw thread elements (not shown) which are actuated ~y rotatio~
of crank handles 28 located ajacent opposing ends of the work-bench whereby to permit the gap between the top members 12 to be varied at will. As described in the above noted U.S. Patent, - the gap between the top members 12 may be greater at one end : than at the other whereby to allow for the clamping of odd-shaped work pieces.
The workbench includes a plurality of legs 30 1, which are each pivotally attached to the base adjacent a ~:
respective one of the four corners of the base. Each of the legs 30 is movable between an inwardly folded - 7 ~

~S~ 7 inoperativa position corresponding to the lower height of the ~ :
workbench as illustrated in Figure 1 wherein the base 14 is sup~ ~
ported on the floor directly, and outwardly and downwardly ~-inclined operative positions relative to the base corresponding to the higher position of the workbench as illustrated for example in Figure 2. It will be seen hereinalfter that the pivotal attachment of the respec~ive legs 30 to base 14 is such that each of said legs is capable of movement in an arc lying in a plane which is at an acute angle relative to the longitudinal and transverse axes of the rectangular base 14. As shown in the preferred embodiment, the above mentioned planes in which the . ~ -respective legs 30 pivot are parallel to lines arranged .
diagonally relative to the rectangular base member. It will be readily seen from the bottom view of Figure 3 that diagonally opposed pairs of legs 30 are arranged qenerally parallel to respective ones of the diagonal lines A and B. It will of course be appreciated that it is not necessary that the legs be pivoted such that they lie exactly in diagonally oriented planes as indicated above and, in fact, it will be seen from 20 Figure 3 that the legs do in fact deviate from such diagonally ~.
oriented lines by a few degrees. The exact orientation of the legs will depend upon the aspect ratio of the base 14 and will be chosen such as to provide optimum stability of the workbench in both the longitudinal and transverse directions.
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With particular reference to Figures 7-13, it will be seen that each of the legs 30 inc1udes a one-piece elongated sheet metal piece 32 (see Figures 11, 12 and 13) the metal piece ;~
32 having a longitudinally extending crimp 34 therein such that, as seen in cross-section, the edge portions 36 of such leg are -offset from the inwardly disposed portions of the leg sufficiently as to provide the required degree of leg strength. O:E course, the thickness of he metal used will be such as to avoicl buckling . ~ , .- ~ .

86~7 f of the leg 30 in use.
The upper end of each leg 30 is provided with aperture defining means 38 for receiving a pivot pin 40. The aperture defining means 38, as best seen in Figure 8 and Figure 11 comprise e~tended edge portions of the above mentioned one-piece sheet metal structure which is curled around upon itself as best seen in Figure 8 to provide an aperture 42 of the required diameter.
To further strengthen leg 30, the underside of the upper end of same is provided with reinforcement plate 44 as best seen in Figure 9 which is spot welded at points 46 to sheet metal member 32 at spaced points. It will be noted that the uppermost ends of the reinforcement plate 44 include extended portions 48 which extend upwardly to points closely ad~acent the aperture de-fining means 38, as best seen in Figure 8, and are spot welded there in superimposed relation to the metal portions which have been curled to define the above mentioned apertures 42 thereby pro-viding adequate strength and a rigid structure. In addition to the above features, the reinforcement plate 44 includes tab 50 and a generally elongated aperture 52 which cooperata with spring clip means for maintaining the leg either in an inoperative or an ~-operative position as will be descrihed more fully hereinafter.
It will also be seen that the lowermost end of each leg 30 includes inwardly turned metal portions to which is welded a metal plate 55 having an extruded and internally threaded portion 55' which is internally threaded to receive an adjustable floor or ground engaging foot 54. The fo~t 54 is provided with threaded stud 56 and lock nut 58 so that the workbench, in use~ may be ~;
readily leveled~
With further reference to the leg structure, it will be seen particularly from Figures 7 and 11 that the uppex edge portion th~reof delineated by bracket C in Figure 11 is so contoured as to define a line of contact which lies in a single plane as illustrated by bracke~ed portio~ D shown in Figure 7. B~ virtue of this arrangement, thxust forces are generally g S~ 7 distributed along such line of contact thus reducing the possibility of buckling of the sheet metal member 32 during u~e.
These th~ust forces are transmitt~d to the hinge plate 60 which will be described hereinafter.
It should also be noted that the legs 30 are provlded with generally elliptically shaped apertures 63 which are located such that when the legs are in their unfolded operative positions, no interference arises between such legs and the downwardly extending floor engaging feet 64 which are connected to hinge plate ~0 adjacent the four corners of same. It will b course be appreciated here that when legs 30 are in their inwardly folded positions, the adjustable feet 64 of base member 14 rest directly ~
on the floor. `
We will now turn to the hinge plate 60 and the spring clip means 62 associated therewith.
It will be seen from Figure 9 that the hinge plate 60 is of a generally triangular configuration. Hinge Plate 60 is provided`with numerous projection weld ~eatures 65 for resistance ~-wëlding of the hinge plate to the base to securely attach the hinge ;~
plate to the corner of the base 14 in one operation. When attached to the base member 14, the edges 66 and 68 of the base plate are parallel to the associated edges of base 14 with the apex 7~ of the hinge plate being disposed at the associated corner of ba6e 14.
An extruded and internally threaded bore is provided adjacent apex 70 of the hinge plate into which the stud of the adjustable foot 64 is threaded to enable ready adjustment of such foot.
It will be seen from Figure 9 that hinge plate 60 is provided with inwardly recessed portions in each of the sides 66 and 68 to receive the aperture defining means 38 of the leg member 30. Inwardly of these recesses, the hinge plate is provided with integrally formed loops 72~ which may bP provided by a simple metal stamping and forming operation, such loops extending down-wardly from the hinge plate 60 in use and definin~ a channel through which the hinge pin 40 may be passed~ It will ble seen -- }O --s~

from Figure 9 that the aperture defining means 38 of the legs are disposed immediately adjacent to and flank the loops 72 formed in the hinge plate.
It should also be noted here, with reerence to FigurP 7 that the aperture defining means 38 of each leg 30 is capable of contacting and transmitting thrust forces directly to the base 14. Thus, under certain con~itions encountered in use, the aperture defining means 38 can come into direct contact with ~`
the ~ase 14 at point E as shown in Figure 7. This serves, under certain conditions, to take some of the loaa off the hinge pin 40.
We will now turn to the spring clip 62 for resiliently retaining the leg in either the collapsed or the operative posi-tio~. Reference is had particularly to Figures 9 and 10. It ~
will be seen that the spring clip 62 comprises an elongated ~ ;
.
strip of resilient metal and is secured to the underside of the hinge plate 60 by spaced apart fastener means as illustrated in Figures 9 and 10. The opposing ends of the spring clip are pro vided with smoothly curved end portions 78 and 80 respectively.
The curved end portion 80 on one end of spring clip 62 is ar~
ranged to come into engagement with and be deflected by the pre~
viously mentioned tang 50 which is integrally formed with the above noted reinforcement plate 44 welded to leg 30. Thus, as leg 30 is ~eing moved to the operative position, tang 50 contacts end portion 80 and deflects same slightly thereby allowing tang 50 ko move to a position b~hind a portion of such curved end portion 80 as shown in Flgure 10, whereby leg 30 is re~
siliently maintained in the extended operative position. The other curved end 78 on the spring clip 62 is positioned and ar-ranged to come into engagement with and be deflected by edge portion 82 of th~ previously mentioned aperture 52 in :Leg re- ;~
inforcement plate 44. Thus, as leg 30 is swung into the folded inopqrative position in the direction of arrow F, edge portion 82 . , :

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contacts cuxved end portion 78 and deflects same su~ficiently so that edge portion 82 be.comes positioned behind a part of the curved end portion 78 whereby to resiliently maintain leg 30 in the folded inoperative position as shown or example in Figures l and 3.
Thus, by virtue of the above described features, the ~ ;
legs 30 are resiliently retained in either their folded inopera- -tive positions as shown in Figures 1 and 3 or the unfolded down- ~
waxdly and outwardly inclined operative positions as shown in ; ~;
Figures 2, 5 and 6. In the folded inoperative position of legs 30, the adjustable feet 64 of the base 14 make clirect con-tact with the floor and this, as mentioned previously, defines the lower working position of the workbench. With the legs 30 in their unfolded operative positions, the feet 54 of legs 30 contact the floor thus defining the upper working position of the workbench. Furthermore, as mentioned previously, by virtue of the downwardly and outwardly inclined arrangement of leg 30 t their respective floor contacting feet contact the floor a sub-stantial distance outwardly beyond the margins of the base 14, as seen in plan, thereby to provide additional stability to the -~workbench as a whole in the higher working position of same.
It will therefore be seen that the above described embodiment provides an improved foldable leg assembly for use in combination with dual-height workbenches and like devices, which assembly is simple in construction, requires no foldable braces ;~
or stays and which includes an extremely simple bracket or hinge plate structure to connect the legs to the work base bench~ the ;~
legs being constructed and arranged to provide adequate stability to the worKbench in the higher position of same. Those skilled in ~he art will realize that numerous modifications may be made to the described embodiment within the scope o~ the invention and accordingly, in determining the scope of the invention, reference is to be had to the appended claims.

Claims (15)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. In a dual elevation workbench or the like comprising:
bench top means for defining a working surface;
a base defining a rectangular outline;
support structure for supporting said bench top means above said base;
a plurality of legs; and, hinge pivot means for pivotally attaching said legs to said base respectively, each of said legs being pivotally attached to said base so as to be pivotally movable between respective inwardly folded inoperative positions correspond-ing to the lower elevation of the workbench and respective outwardly and downwardly inclined operative positions relative to said base corresponding to the higher elevation of the workbench;
the improvement characterized by said legs being pivot-ally attached to said base by said respective hinge means so as to cause said legs in said operative positions to extend outwardly in respective directions defined substantially by the diagonals of said rectangular outline and away from said rectangular base in splayed fashion to locations on the floor outside of and beyond a plan projection of said bench top means and said base on the floor whereby the workbench will remain in static equilibrium irrespective of where a load is applied to said working surface and said base.

2. A workbench according to claim 1 wherein said hinge pivot means of each leg includes aperture defining means formed on said leg for receiving a pivot pin oriented to provide said movement of the leg.

3. A workbench according to claim 2 wherein each said hinge pivot means includes a hinge plate secured to said base, said hinge plate comprising a plate having loops formed therein receiving the pivot pin, said loops disposed immediately adjacent said aperture defining means.

4. A workbench according to claim 2 wherein each said leg includes a one-piece elongated sheet metal piece having a longitudinally extending crimp therein such that, as seen in cross-section, edge portions of such leg are offset from inwardly disposed portions of the leg sufficiently to assist in providing the required degree of leg strength.

5. A workbench according to claim 4 wherein an upper end of said leg adjacent said hinge pivot means is shaped such that it defines a line of contact lying in a single plane and adapted to contact said base whereby thrust forces transmitted between the base and the upper end of the leg are distributed along said line.

6. A workbench according to claim 3 wherein each said leg includes a one-piece elongated sheet metal piece having a longitudinally extending crimp therein such that, as seen is cross-section, edge portions of such leg are offset from inwardly disposed portions of the leg sufficiently to assist in providing the required degree of leg strength.

7. A workbench according to claim 6 wherein an upper end of said leg adjacent said hinge pivot means is shaped such that it defines a line of contact lying in a single plane and adapted to contact said base whereby thrust forces transmitted between the base and the upper end of the leg are distributed along said line.

8. The workbench according to claim 6 wherein the aperture defining means of each said leg is capable of con-tacting and transmitting thrust forces to said base.

9. The workbench according to claim 1 wherein said base is of generally rectangular configuration with said leg members each being connected thereto adjacent a respective one of the four corners of the base.

10. The workbench according to claim 1 including means fox resiliently holding each said leg in the folded inoperative position and the outwardly disposed operative position.

11. The workbench according to claim 1 wherein said base is provided with a plurality of support feet for contacting a floor surface in the lower elevation of the work-bench, each support foot being located at a respective corner of the base adjacent a respective one of said legs, each of the legs being provided with a respective floor contacting means with said legs being shaped such that when the legs are in their operative positions their floor contacting means are disposed a substantial distance outwardly beyond the margins of the base, as seen in plan, to provide added stability to the workbench in the higher elevation of the latter.

12. The workbench according to claim 1 wherein said support structure for supporting said bench top means above said base has pivot means associated therewith to permit the workbench to be collapsed and the top members brought into juxtaposition with the base for ease of transport and storage of the workbench.

13. The dual elevation workbench of claim 1, each of said legs being an elongated sheet metal member.

14. In a dual elevation workbench or the like com-prising:
bench top means for defining a working surface;
a base;
support structure for supporting said bench top means above said base;
a plurality of legs; and, hinge pivot means corresponding to respective ones of said legs for pivotally attaching said legs to said base adjacent outer edge portions thereof so as to be pivotally movable between respective inwardly folded inoperative posi-tions corresponding to the lower elevation of the workbench and respective outwardly and downwardly inclined operative positions corresponding to the higher elevation of the work-bench, the improvement characterized by the pivotal attach-ment of the respective legs being such that in said operative positions said legs extend outwardly away from said base in splayed fashion to locations on the floor outside of and be-yond a plan projection of said bench top means on the floor, each of said legs having structure means engaging said base outboard of said corresponding hinge pivot means for coacting with said hinge pivot means to transmit thrust forces developed by loads applied to said working surface from said base to said floor locations whereby the workbench will remain in static equilibrium irrespective of where a load is applied to said working surface.

15. The dual elevation workbench of claim 14, each of said legs being an elongated sheet metal member.