US633233A - Adjustable scaffold-trestle. - Google Patents

Description

No. 633,233; I Patentad Sept. l9, I899.

vI. DAVIS.

ADJUSTABLE SCAFFOLD TRESTLE.

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(No Model.)

illlilmlllllilllllllllll UNITED I STATES PATENT OFFICE.

IRVIN DAVIS, OF COLUMBIA, MISSOURI.

ADJUSTABLE SCAFFOLD-TRESTLE.

SPECIFICATION forming part of Letters Patent No. 633,233, dated September 19, 1899.

Application filed June 3, 1897.

To all whom it may concern:

Be it known that I, IRVIN DAVIS, of Columbia, in the county of Boone and State of Missouri, have invented certain new and useful Improvements in Adjustable Scafiold-Trestles; and I 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 appertains to make and use the same.

The invention relates to an adjustable scaffold-trestle for the use of lathers, plasterers, and others for giving a substantial and reliable support in proper relation to the work in which they are engaged.

To this end it consists in the combination, with the folding and expansible supports or supporting-legs arrangedin pairs in X shape, of an extensible girder or scaffolding-supporting bar, the parts of said bar being provided with hooks which engage the supports and having sliding connection with each other and retaining and guiding loops, as hereinafter described and claimed.

In the accompanying drawings, Figure 1 is a perspective view of one of the trestles complete. Fig. 2 is a detail View of the adjoining faces of the extensible scaffold-supporting-bar or girder. Fig. 3 is a similar view of a modification of the devices connecting the parts of said bar, and Figs. 4, 5, and 6 are perspective views showing certain details of construction hereinafter referred to.

1 1 and 2 2 indicate supporting-legs of the trestle arranged in parallel pairs, as indicated, those of one pair crossing those of the other pair in X form, as shown, and being pivoted together at or near the centers of their length. To one pair of these bars or uprights 2 2, which are made of less width than those of the pair 1 1, so as to fit between the latter, are secured angle-iron plates 3, the uprights of which are rigidly secured to the bars 2 2. Near the angles of theseirons 3 pivots extend through said irons and through the legs upon one side of each pair of supports, forming a pivotal connection between the pairs indicated at 4. To the upper end of these irons are secured transverse rods or through-bolts 6 6, for a purpose that will appear.

Serial No. 639,275. (No model.)

7 indicates an extensible girder or scaffolding-support, composed of two parallel bars 8 9, placed side by side, and one of which, in Fig. 2, is shown provided with a groove 10 on its inner face, the other bar 9 being pro vided with a tongue 11, which enters and is adapted to slide in the groove 10 in a manner that will be readily understood, thereby holding the two parts of the extensible girder in uniform relation to each other. In Fig. 3, instead of being tongued-and-grooved, as in Fig. 2, the bars 8 9 are shown, one provided with a longitudinal slot at 12, through which a bolt secured to the bar 9 is adapted to'slide, said bolt being flattened on the portion which passes through the bar 8 to adapt it to slide smoothly in the slot 12, the other end of said bolt being rounded and screw-threaded t0 receive a nut 13 for holding the two bars in engagement one with the other. To one of -these bars 8 are secured at each end rods or angle-iron straps 1.4, which are secured to the bar 9, and through which the bar 8 is adapted to slide endwise for permitting longitudinal adjustment of the bars relatively to each other, as required.

notched straps 15, provided each at its outer end with an inwardly-inclined notch 16, made substantially hook-shaped on its lower face, as shown in Fig. 4, to engage the transverse rods 6 on the upper end of the outer bars 1, and inside of said notches are formed a number of oppositely-inclined notches 17, opening downward and also having hook-shaped inverted lower faces to engage the rods 6 of the inner bars 2, the construction being such that when the transverse rods or bars in the upper ends of the pairs of supporting-legs are engaged, one with the notch 16 and the other with any one of the notches 17,they will be held securely in said notches, and any sliding or expansion of the folding support effectually prevented; By expanding the support 2 relatively to the support 1 the rod 6 may be made to engage any one of said notches, as explained, and in so doing the girder 8 will be lowered for giving it the required height, in a manner that will be readily understood.

In Fig. 5 I have shown the parts of the folding trestle-support, and in Fig. 6 the angle- To the lower faces of the bars 8 9 are secured irons which connect the parts of the divided or extensible girder for guiding and permittingthelongitudinaladjustmentofsaid parts.

By the construction of the girder and of the supporting-trestle as described it will be seen that the girder may be raised and supported at any desired height, and by the longitudinal adjustment of the parts of the girder any required width of trestle-support may be given, and at the same time when the trestle is not in use the parts thereof are adapted to be detached or separated from each other and folded into com pact shape for tran sportation.

Having thus described the invention, what I claim as new, and desire to secure by Letters Patent, is

1. In a trestle, the combination, with the saw-horse-like supports each comprising two pivoted-together members, and the extensible girderorbarcomprising two endwisemovable members, each having upon its under side oppositely or reversely facing notches adapted to engage top cross bars or rods of said saw-horse-like supports,substantially as set forth.

2. In a trestle, the combination, with the saw-horse-like supports, each comprising two pivoted-together members, one having its uprights united by an angle-iron having pivots passing through and forming pivotal con nections between said members, and the extensible girder or bar comprising two endwisemovable members,'each having secured upon its under side oppositely or reversely facing notches, adapted to engage top cross bars or rods of said saw-horse-like supports, substantially as set forth.

3. In a trestle, the combination, with the saw-horse-like supports each comprising two pivoted-together members, one havingits uprights united by an angle-iron having pivots passing through, and forming pivotal connections between, said members, and the extensible girder or bar comprising two endwisemovable members, each having a plate provided with reversely or oppositely facing notches adapted to engage top cross bars or rods of said saw-horse-like supports, said members of said extensible girder, being clipped, and tongue-and-grooved, together, substantially as set forth.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

IRVIN DAVIS.

Witnesses:

JOHN DODSON, N. V. EDWARDS.

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