US390103A - Extension-trestle - Google Patents

Description

(No Model.)

J. E. WALLACE 81; C. D. REESE.

EXTENSION TRESTLB.

No. 390,103. Patente@ sept. 25, 1888.

of the trestle.

UNITED STATES JAMES E. VALLAGE AND CHARLES D EXTENSION or LA onossn, w sooNsiN.

-TRESTLE SPECIFICATION forming part of Letters Patent No. 390.103, dated September 25, 1888.

Application filed May 15. ISES. SerialNo.273.934. (No model.)

To aZZ whom t may concern:

Beit known that we, JAMES E VVALLACE and CHARLES D. REEsE, residents of La Crosse, in the county of La Crosse and State of Visconsin, have invented certain new and useful Improvements in Exteusion-Trestles; and we do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it pertains to make and use the same.

Our invention relates particularly to trestles such as are used by workmen for supporting platforms and seaifolds, and is intended to afford adj ustability in both the length and height of each trestle employed.

In the drawings herein referred to by letters, Figure l is a side elevation of a part of our trestle. Fig. 2 is an end elevation of the same. Fig. 3 is a top plan with the legs folded. Fig. et is an enlarged view of the upper part of one leg. Fig. 5 is an enlarged view, partly in section, showing the leg seen in Fig. 2. Fig. 6 is a section through fr i, Fig. l. Fig. 7 is a section similar to Fig. 6, but through the clip E, illustrating a slightlymoditied construction.

In the drawings, A A' are two continuous overlapping bars forming the horizontal part Upon the lateral face of one of these is rigidly fastened a smaller rectangular bar, D, and upon the opposite one are irmly tixed two or more rigid clips, E, which pass beneath the first bar and are provided with vertical arms E', bent at right angles to form hooks that rest upon the upper side of the bar D and prevent vertical or lateral separation of the bars A A', and, as these clips are at some distance apart, theytogether keep the bars inthe same horizontal plane. At the same time they allow free longitudinal movement of the bars with reference to each otherthat is, permit the lengthening or shortening of the trestle.

The bars A A' are supported by legs each made up of two overlapping members, B B'. The upper members, B B, of each pair are `joined by a horizontal bar, I, and by a bolt, C, which at the same time pivots them securely upon the barA or A'. A wing-nut,0, serves t0 clamp them in any desired position with reference to the bar A. When in working position, as in Fig. l, they are further held by a detachable brace-rod, J, vpassing from the bar A to the middle of the cross-bar I. Each of these members is grooved upon the outer face at L, Fig. 5, and over the groove is fixed a plate, G, provided with perforations H. rIhese members are further provided with loops K, fixed upon their lower ends and adapted to receive the lower sliding members, B'.y rIlhe upper ends of the latter are provided with metallic hooks N, adapted to enter the perforations H and slide beneath the intervening parts of the plates G. In adjusting the legs the free end of the hook N passes squarely through one of these apertures, and then with the member B', towhich it is attached, it 1s moved slightly upward to engage the plate G. A set-screw, M, in the outer side of the loop K is then screwed firmly against the member B',securing itin position. When the legs are to be folded-as in transportation, for examplethe brace-bar .I is removed entirely, or one of its ends is released and it is then swung about the opposite retaining-bolt to such position that it may not prevent the folding of the legs,y as indicated in Fig. 3.

For greater strength we have placed the bar D in a recess in the inner face of the bar A, and provided the clip with a central hook,.F, Fig. 7, lying in and' projecting from the inner face of the bar A' to engage the bar D; but for most uses the tirst construction affords sui-licient strength.

Vhat we claim as new, and desire to secure by Letters Patent, is-

l. The combination, with the bar A, ofthe recessed legs B, pivotally secured thereto and provided with the perforated plates G and the loops K, and the overlapping members B', passing through said loops and having the hooks N, adapted to enter the perforations in said plate, substantially as and for the purpose set forth.

2. In an exlension-trestle, the combination, with two overlapping bars, A A', in the same horizontal plane forming the body of the trestle, ofa bar, D, rigidly secured upon the side of one of them, and clips rigidly fastened to specification in the presence of two subscribthe other and passing transversely under said ing Witnesses.

bars, and having vertical arms E, bent at right JAMES E. WALLACE.

angles to engage the bar D, whereby the over- CHARLES D. REESE. 5 lapping bars are permitted to movelongitudi- Witnesses:

nall y only with reference to each other. JOHN BRINDLEY7 In testimony whereof We have signed this JOHN J. FRUIT.

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