US 300887 A
Description (OCR text may contain errors)
(No Model.) I w E. OWE-N.
No. 300,887. Patented June 24,1884
INVENTOR WITNESSES: v Mimmwm.
lJNrrED STATES PATENT Orrrcs.
EDWARD OWEN, OF JACKSON, TENNESSEE.
\ ADJUSTABLE TRESTLE.
SPECIFICATION forming part of Letters Patent No. 300,887, dated June 24, 1884.
Application filed April 7, 1884.
To wZZ whom it may concern;
Be it-known that I, EDWARD OWEN, of J ackson, in the county of Madison and State of Tennessee, have invented a new and Improved Adjustable Trestle, of which the following is a full, clear, and exact description.
My invention relates to trestles for supporting scaffolding for the use of carpenters, bricklayers, and others; and it consists of a trestle having a slotted top bar and a mortised longitudinal beam placed below the said bar and adapted to receive a frame, whose side bars are provided with internal ratchet-teeth, which are engaged by pawls pivoted to the longitudinal bar, the said frame being provided with a central bar having a series. of transverse pins for receiving a lever employed to raise the frame in the trestle.
Reference is to be had to the accompanying drawings, forming part of this specification, in
which similar letters of reference indicate corresponding'parts in all the figures.
. Figure 1 is a side elevation of my improvec trestle. Fig. 2 is an end elevation, and Fig. 3 is a detail view of the lever employed to operate the trestle.
The trestle formed of a slotted top bar, A, supported by divergent legs B, is provided with a longitudinal beam, 0, which is secured between the legs B a short distance from the top bar, A, and ;'parallel with it. The beam O is mortised to receive the vertical bars a a and b of the frame D, which passes through the slot of the top bar, A. The bars a a and b are connected at the bottom to a bar, a, and at the top to a bar, cl, which is prolonged at one end beyond the side bar of the frame. A block, E, corresponding in width and thickness to the bar (1, is secured to the top bar, A, at the side of the frame D. The prolongation of the bar (Z supports the scaffolding used in connection with the trestle over the extreme (No model.)
which are engaged by oppositely arranged pawls, f, hinged to the beam 0, and capable of resting against shoulders formed on the said beam The bar I) is located centrally in the frame D, and extends through the slot in the top bar, A, and through a mortise in the beam 0, and is provided with a series of pins,,h, passing through the bar and projecting equally on each side thereof. The pins are engaged by a forked lever, G, which is tilted on the bar Fas a fulcrum, and is employed in raising the frame D. As a safeguard in lowering the frame D, a rope, H, secured to the bar a, and extending upward through the mortise in the beamO and through a hole, 2', in the top bar, A, is employed. This rope in use is to be passed around the bar F. When the frame D is lowered or raised by the engagement of the forked lever G with one of the pins, the
frame D is retained at the required height by the engagement of the pawls f with the notches e in the side bars, a a. Holes j are placed at suitable distances in the bars a a to receive pins k, which pass through the said bars and rest upon the slotted top bar, A. The pins are secured to the trestle by means of a flexible cord, so as to be always at hand and ready for use. The legs 13 are provided with casters Z, which permit of moving the trestle eas ily in one direction or the other.
My improved scaffold is particularly adapt-- ed to the use of carpenters, painters, and bricklayers, and may be raised or lowered while the workmen are supported by the scaffolding without interfering with their work.
I am aware that the vertically-adjustable bars of a trestle have been provided with teeth,
with which teeth cog-wheels on a transverse shaft on the supporting-frame meshed; also, that a transverse shaft was arranged on the said frame, said shaft having pawls for engaging the teeth; also, that thecentral bar of the vertically-adjustable trestle frame has been provided with teeth for engaging a pinion on a shaft on the frame for use in raising the trestle, these adjustable bars passed through a slotted cross-bar on theframe. Having thus described my invention, I claim as new and desire to secure by Letters Patent- 1. The combination, with a trestle provided with a slotted top bar, A, and mortised beam 0, formed with shoulders g, of aframe, D, hav- .3. The frame D, provided with a. bar, I having notched side bars, a a, and the pawls f, 'ing transverse pins 71, a trestle adapted to suphinged to the beam 0, and capable of engagport the frame D, and provided with a bar, ing the notches of the barsa a at their free F, and the forked lever G. in combination, as 15 5 ends and bearing against the shoulders g at described.
their hinged ends, as described.
2. The combination, with the frame D, hav- EDVARD OWEN.
ing notched side bars, a a, of the bar b, provided with transverse pins h, adapted to re- Vitnesses: o ceive a lever for elevating the frame D, as de- THOS. CLARK,
scribed. W. H. 'BRUTON.