US3212606A

US3212606A - Trestle structure

Info

Publication number: US3212606A
Application number: US295742A
Authority: US
Inventors: Melvin O Spaw
Original assignee: Individual
Current assignee: Individual
Priority date: 1963-07-17
Filing date: 1963-07-17
Publication date: 1965-10-19
Anticipated expiration: 1982-10-19

Description

Oct. 19, 1965 M. o. SPAW 3,212,606

TRESTLE STf- IUGTURE Filed July 17, 1963 2 Sheets-Sheet 1 INVENTOR. MELVIN O. SPAW Q/mJ Qwi-I M ATTORN EYS Oct. 19, 1965 1 M. o. sPAw 3,212,606

TRESTLE STRUCTURE Filed July 17, 1963 v 2 Sheets-Sheet 2 INVENTOR. MELVIN O. SPAW ATTORNEYS United States Patent 3,212,606 TRESTLE STRUCTURE Melvin O. Spaw, 7227 Kumfer Ave., Fort Wayne, Ind. Filed July 17, 1963, Ser. No. 295,742 2 Claims. Cl. 182-185) This invention relates generally to trestle structures, and more particularly to a collapsible trestle sructure for supporting carpenters saw horses, scaffolding and the like.

Trestle structures conventionally comprise a horizontal beam element and a pair of leg elements for supportting the beam, and are employed for such uses as carpenters saw horses and for supporting other structures, such as scaffolding, staging and the like. It is desirable that such trestle structures be collapsible for transportation and storage, and a number of collapsible trestle structures are commercially available. However, such prior collapsible trestle structures known to the present applicant have been characterized either by excessive weight or by their complexity and relatively high cost. It is therefore desirable to provide a collapsible trestle structure which is characterized by its light weight, ready assembly and disassembly, simplicity and relatively low cost, the structure nevertheless providing the requisite strength and rigidity when assembled.

It is also desirable that a trestle structure be designed to be completely stable even when set upon uneven terrain. Prior trestle structures have either been completely unstable as exemplified by the rocking of a four-legged structure having one leg supported at a higher or lower level than the other three, or have been structurally weak; four-legged trestle structures with legs adjustable in length and three-legged trestle structures have been normally weaker than their four-legged counterparts. It is therefore desirable to provide a four-legged trestle structure that is completely stable when set upon uneven terrain.

It is further desirable that such a trestle structure be readily adapted selectively to provide two different trestle heights. It may also be desirable to provide readily releasable means for positively locking the trestle structure in the assembled position.

It is accordingly an object of the invention to provide an improved collapsible trestle structure.

Another object of the invention is to provide an improved collapsible trestle structure characterized by its light weight, simplicity, ease of assembly and disassembly, strength and rigidity.

A further object of the invention is to provide an improved collapsible trestle structure which is readily adaptable selectively to provide two different trestle heights.

A still further object of the invention is to provide an improved trestle structure which is completely stable when set upon uneven terrain.

Yet another object of the invention is to provide an improved collapsible trestle structure incorporating readily releasable means for locking the structure in the assembled position.

Further objects and advantages of my invention will become apparent by reference to the following description and the accompanying drawing, and the features of novelty which characterize my invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

In accordance with the broader aspects of the invention, there is provided a collapsible trestle structure incorporating a horizontal beam element having top and bottom edges and a pair of leg structures for supporting the beam element. Each of the leg structures comprises a bracket portion having top and bottom vertically spaced 3,212,606 Patented Oct. 19, 1965 cross-bar means respectively connected at their opposite ends by horizontally spaced side bar means, the bracket portion being removably positioned on the beam element with the top and bottom cross-bar means respectively engaging the top and bottom edges thereof. A pair of legs depend from the bracket portion and the top and bottom cross-bar means are spaced apart by distances greater than the spacing between the top and bottom edges of the beam element, thereby permitting the bracket portion to be assembled on and removed from the beam element. The bracket portion, when assembled, fits loosely on the beam element, having sufficient play so that each pair of legs can be cocked angularly with the beam element, the legs still supporting the beam element with a high degree of stability.

In the drawing:

FIG. 1 is a side elevational view of one embodiment of the invention showing the legs positioned to support the beam element in its lower position;

FIG. 2 is a side view showing the legs reversed to support the beam element in the upper position thereof;

FIG. 3 is an end view taken generally along the line 33 of FIG. 1 showing a set of legs cocked angularly to the beam element;

FIG. 4 is a side view showing another embodiment of the invention;

FIG. 5 is an end view of the embodiment of FIG. 4 showing a set of legs cocked angularly to the beam element; and

FIG. 6 is a fragmentary view, partly in cross-section, showing the locking assembly of FIGS. 4 and 5 in unlocked position. v

Referring now to FIGS. 1, 2 and 3 of the drawing, there is shown an elongated beam element 10, which, for example, may be a wood two-by-four having

sides

11 and 13 and top and

bottom surfaces

12, 14, respectively. Generally rectangular notches 16 and 18 are cut in the top side 12 of beam 10 adjacent its

opposite ends

20, 22, as shown.

In order selectively to support beam 10 at either of two heights above the ground or other supporting surface 25, as shown in FIGS. 1 and 2, a pair of

identical leg structures

24, 26 are provided, each preferably fabricated from suitable tubular metal or metal rod, such as steel. Each of the

leg structures

24, 26 comprises a generally 0- shaped bracket portion 28 having vertically spaced, parallel, top and

bottom cross-bar elements

30, 32 respectively joined at their opposite ends by horizontally spaced, parallel,

side bar elements

34, 36. A pair of

elongated leg elements

38, 40 respectively divergently depend from the bracket portion 28 and have a transversely extending ground-engaging bar 42 attached to their lower ends, as best seen in FIG. 3.

The

cross-bar elements

30, 32 of each of the

leg structures

24, 26 are vertically spaced apart by a distance greater than the vertical spacing between the bottom surfaces 44 of notches 16, 18 and the bottom side 14 of beam element 10 in order to permit the bracket portions 28 to be assembled on and removed from the beam element. When assembled on the beam element 10, the top and

bottom cross-bar elements

30, 32 respectively engage the surfaces 44 of notches 16, 18,

side bar elements

34 and 36 being spaced apart from

sides

11 and 13, and the bottom side 14 of the beam element 10 and are disposed at angles with respect thereto, as seen in FIGS. 1 and 2. It will be seen that the bracket portion 28 and the

legs

38, 40 of each of the

leg structures

24, 26 are respectively disposed in two planes which define an obtuse angle 46, preferably on the order of therebetween. It will now be seen that by virtue of the provision of this obtuse angle 46 between the bracket portions 28 and the

legs

38, 40 of the

leg structures

24, 26, when the leg structures are arranged with the obtuse angles 46 facing outwardly, as shown in FIG. 1, the beam 10 is supported by the

leg structures

24, 26 in a lower position, whereas, when the

leg structures

24, 26 are reversed so that the obtuse angles 46 face inwardly, as shown in FIG. 2, the beam element 10 is supported in the higher of its two positions.

It will be further seen that by arranging one leg with the obtuse angle 46 facing outwardly and the other leg with the obtuse angle 46 facing inwardly, the elongated beam 10 may be positioned horizontally on terrain that is inclined from the horizontal by means of this invention.

Referring now to FIGS. 4, 5 and 6, in which like elements are indicated by like reference numerals, there is shown an embodiment of the invention incorporating a releasable locking mechanism for securely holding the leg elements in their assembled position. Here, a relatively short beam element is shown having a single notch 16 formed in its upper surface 12 in which the top cross-bar elements 30 of both of the

leg structures

24, 26 are positioned when the trestle is assembled; otherwise, cross-bar 32 is positioned adjacent surface 14 of member 10 and

side bar elements

34 and 36 are spaced apart from

sides

11 and 13 as in the first disclosed embodiment of this invention. It will be readily understood that a longer beam element 10 having two spaced notches 16, 18 as shown in FIGS. 1 and 2 may be employed with this embodiment.

Here,

transverse bar elements

48 and 50 respectively connect

legs

38, 40 of the

leg structures

24, 26. Locking mechanism 52 comprises a lever member 54 pivotally connected to bar element 48, as best seen in FIG. 6. A rod member 56 is provided having a shoe 58 at one end there of adapted to engage transverse bar 50 when the trestle is then in its assembled position. A collar 60 is secured to the other end of rod 56 and another collar 62 is secured thereto spaced from collar 60. A sleeve 64 is slidably positioned on rod 56 and is pivotally connected to the lever 54 intermediate its ends, as at 66. A suitable coil spring 68 is positioned on the rod 56 between collar 62 and sleeve 64 and biases sleeve 64 toward and normally into engagement with collar 60. An actuating handle 70 is secured to the end of lever 54 remote from its pivotal connection to the transverse bar element 48. A stop element 72 is secured to the lever 54 intermediate its pivotal connection 66 and the transverse bar element 48 and extends transversely so as to engage sleeve 64 on rod member 56 when the locking mechanism 52 is in its locking position.

It will now be readily seen that the locking mechanism 52 is selectively movable between two over-center positions, i.e., a locking position as shown in FIG. 4 and an unlocked position as shown in FIG. 6. In order to assemble the trestle structure of FIGS. 4, 5 and 6, the bracket portions 28 of the two

leg structures

24, 26 are assembled on the beam 10 with their top cross-bar elements 30 respectively seated in notch 16, shoe 58 of the rod 56 is placed in engagement with transverse bar element 50, and the lever 54 is raised by means of the handle element 70 to its locking over-center position, as shown in FIG. 4, with the stop element 72 retaining the locking mechanism 52 in its locking position. In order to release the locking mechanism, it is merely necessary to push downwardly upon the handle element 70 thereby moving the lever member 54 and the sleeve member 64 against spring 68 through the neutral position of the mechanism into its unlocked position which releases shoe 58 from transverse bar element 50. Following the unlocking operation, the bracket portions 28 of the

leg structures

24, 26 may be removed from the beam 10 and the component elements then readily transported to another site; it will readily be seen that the locking mechanism 52, when in its unlocked position, will pivot downwardly by virtue of the pivotal connection of lever member 54 with the transverse bar element 50 into a position between the

legs

38, 40 of the leg structure 24.

It will readily be seen that the positions of the

leg elements

24, 26 of the trestle structure of FIGS. 4, 5 and 6 may be reversed together or singularly as in the embodiment of FIGS. 1, 2 and 3 to provide a lower height for the beam element 10 or to accommodate an inclined terrain; in which event, if leg 24 is reversed, handle element 70 of the locking mechanism 52 will be pushed downwardly to move the locking mechanism into its locking position and pulled upwardly to unlock the mechanism.

It will also be readily seen that between

cross-bar elements

30 and 32 and

surfaces

44 and 14 of beam element 10 and similarly between

side bar elements

34 and 36 and

sides

11 and 13 of beam member 10 is sufficient distance to allow

leg structure

24 or 26 to be cocked angularly to beam member 10. This allows adjustment to be made in the elevation of the

leg structures

24 or 26 in either of the embodiments of this invention to accommodate uneven terrain without derogating from the rigid and stable support given beam 10 when either embodiment is positioned on flat terrain.

While I have illustrated and described a specific embodiment of my invention, further modifications and improvements will occur to those skilled in the art and I desire therefore in the appended claims to cover all modifications which do not depart from the spirit and scope of my invention.

What is claimed is:

1. A collapsible trestle comprising: a horizontal beam element having sides, opposite ends, top and bottom edges, and notch means in said top edge intermediate said ends, said notch means having at least two transverse surface portions and a bottom surface portion; a pair of leg structures for supporting said beam element, each of said leg structures comprising a bracket portion having horizontal top and bottom cross-bar means respectively connected at their opposite ends by spaced vertical side bar means, said bracket portions being removably positioned on said beam element with said top crossbar means engaging one of said transverse surfaces of said notch means, respectively, thereby to prevent movement of said bracket portion longitudinally of said beam element, and a pair of legs depending from said bracket portions, respectively, said side, top and bottom bar means being spaced apart by distances greater than the spacing between said sides and said top and bottom edges of said beam element, respectively; and releasable lock means having an axis and one end connected to one of said leg structures and its other end removably engageable with the other of said leg structures, said other end being rotatable about said axis, said lock means including resilient means connecting said ends and having a first over-center position connecting said leg structures and holding the same apart when said leg strucures are assembled on said beam element, and a second overcenter position with said other end of said lock means disengaged from said other leg structure thereby permitting removal of said leg structures from said beam element, whereby said bracket portion may be assembled on said beam element and cocked angularly with respect to said beam element so as to provide stable support for said beam element on uneven terrain.

2. A collapsible trestle comprising: a horizontal beam element having top and bottom edges; a pair of leg structures for supporting said beam element, each of said leg structures comprising a generally O-shaped bracket portion formed of metal having vertically top and bottom cross-bar elements respectively joined at their opposite ends by horizontally spaced side bar elements, said bracked portion removably receiving said beam element with said top and bottom cross-bar elements respectively engaging said top and bottom edges thereof, and a pair of horizontally spaced elongated leg elements formed of metal joined to said bracket portion and divergently depending therefrom, said cross-bar and side elements being spaced apart by a distance greater than the spacing between said edges of said beam element whereby said bracket portion may be assembled on and removed from said beam element and said side bar elements are disposed at an angle with respect to said beam element when said cross-bar elements respectively engage said beam element edges and whereby said bracket may be cocked angularly with said beam element so as to provide stable support for said beam element on uneven terrain; and a transverse bar connecting the leg elements of each of said leg structures; and releasable lock means comprising a lever member pivotally connected to said transverse bar of one of said leg structures, a rod member having means on one end thereof for removably engaging said transverse bar of the other of said leg structures, a sleeve member slidably mounted on said rod member and pivotally connected to said lever member intermediate its ends, stop means on said rod member adjacent the other end thereof for limiting the movement of said 20 sleeve member thereon, and spring means resiliently urging said sleeve member toward said stop means whereby said lock means has a first over-center position con- References Cited by the Examiner UNITED STATES PATENTS 861,583 7/07 Foster 182176 2,794,496 6/57 Strand 108-153 FOREIGN PATENTS 245,036 6/47 France. 3 59,872 3 62 Switzerland.

HARRISON R. MOSELEY, Primary Examiner.

REINALDO P. MACHADO, CHARLES E. OCON- NELL, Examiners.

Claims

1. A COLLAPSIBLE TRESTLE COMPRISING: A HORIZONTAL BEAM ELEMENT HAVING SIDES, OPPOSITE ENDS, TOP AND BOTTOM EDGES, AND NOTCH MEANS IN SAID TOP EDGE INTERMEDIATE SAID ENDS, SAID NOTCH MEANS HAVING AT LEAST TWO TRANSVERSE SURFACE PORTIONS AND A BOTTOM SURFACE PORTION; A PAIR OF LEG STRUCTURES FOR SUPPORTING SAID BEAM ELEMENT, EACH OF SAID LEG STRUCTURES COMPRISING A BRACKET PORTION HAVING HORIZONTAL TOP AND BOTTOM CROSS-BAR MEANS RESPECTIVELY CONNECTED AT THEIR OPPOSITE ENDS BY SPACED VERTICAL SIDE BAR MEANS, SAID BRACKET PORTIONS BEING REMOVABLY POSITIONED ON SAID BEAM ELEMENT WITH SAID TOP CROSSBAR MEANS ENGAGING ONE OF SAID TRANSVERSE SURFACES OF SAID NOTCH MEANS, RESPECTIVELY, THEREBY TO PREVENT MOVEMENT OF SAID BRACKET PORTION LONGITUDINALLY OF SAID BEAM ELEMENT, AND A PAIR OF LEGS DEPENDING FROM SAID BRACKET PORTIONS, RESPECTIVELY, SAID SIDE, TOP AND BOTTOM BAR MEANS BEING SPACED APART BY DISTANCES GREATER THAN THE SPACING BETWEEN SAID SIDES AND SAID TOP AND BOTOM EDGES OF SAID BEAM ELEMENT, RESPECTIVELY; AND RELEASABLE LOCK MEANS HAVING AN AXIS AND ONE END CONNECTED TO ONE OF SAID LEG STRUCTURES AND ITS OTHER END REMOVABLY ENGAGEABLE WITH THE OTHER OF SAID LEG STRUCTURES, SAID OTHER END BEING ROTATABLE ABOUT SAID AXIS, SAID LOCK MEANS INCLUDING RESILIENT MEANS CONNECTING SAID ENDS AND HAVING A FIRST OVER-CENTER POSITION CONNECTING SAID LEG STRUCTURES AND HOLDING THE SAME APART WHEN SAID LEG STRUCTURES ARE ASSEMBLED ON SAID BEAM ELEMENT, AND A SECOND OVERCENTER POSITION WITH SAID OTHER END OF SAID LOCK MEANS DISENGAGED FROM SAID OTHER LEG STRUCTURE THEREBY PERMITTING REMOVAL OF SAID LEG STRUCTURES FROM SAID BEAM ELEMENT, WHEREBY SAID BRACKET PORTION MAY BE ASSEMBLED ON SAID BEAM ELEMENT AND COCKED ANGULARLY WITH RESPECT TO SAID BEAM ELEMENT SO AS TO PROVIDE STABLE SUPPORT FOR SAID BEAM ELEMENT ON EVEN TERRAIN.