US574486A - Trestle - Google Patents

Description

(No Model.)

C. A. JONES.

TRESTLE.

Patented Jan. 5,1189 7.

lnz/niar,

Chaim v9. fines,

' brace members.

UNITED STATES PATENT OFFICE.

CHARLES A. JONES, OF HARTFORD, CONNECTICUT.

T R E S T L E SPECIFICATION forming part of Letters Patent No. 574,486, dated anuary 5, 1897'.

Application filed October 26, 1896. Serial No. 610,017. (No model.) I

To aZZ whom it may concern.-

Be it known that 1, CHARLES A. JONES, a citizen of the United States, residing in Hartford, in the county of Hartford and State of Connecticut, have invented certain new and useful Improvements in Trestles, of which the following is a specification.

This invention relates to trestles of that class used by carpenters and builders for supporting staging, dye.

One object of the invention is to furnish a simple, durable, and efficient trestle of the knockdown type which may be readily folded up and transported from place to place and which embodies means whereby the same may be quickly set up and adjusted to different heights or lengths without the employment of bolts, screws, or other extraneous attaching devices commonly used with adj ustable trestles of this class of ordinary construetion.

A further object of the invention is to provide a trestle-beam support of improved construction and organization embodying a pair of pivotally-connected beam-clamping legs or beam-supporting members, a pair of beamclamping brace members pivotally connected together near their outer ends and pivotally connected at their inner ends, one to each beam-supporting leg, and means carried by the beam-clamping legs and effective for spreading the connected ends of the legs and brace members simultaneously,to thereby effeet a clamping movement of the beam-clamping ends of said members, all of which will be hereinafter more fully described.

In the drawings accompanying and forming part of this specification, Figure l is a Side elevation of a trestle embodying my present invention. Fig. 2 is an end View of the same as seen from the left hand in Fig. 1. Fig. 3 is an enlarged view, as seen from the inner side, of a portion of the upper end of the beam-clamping legs. Fig. 4 is an enlarged view of the upper end of the beam-clamping Fig. 5 is an enlarged crosssectional View, taken in line a a, Fig. 1, showing .a portion of one of the extensible legs and a clamping device in connection therewith; and Fig. 6 is a side View of the beamsupport folded for transportation.

Similar characters designate like parts in all the figures of the drawings.

The trestle in its entirety, as shown most clearly in Fig. 1, comprises a trestle-bean1 or ledger (designated by B) and two foldable and adjustable beam-supports (designated'by S and S, respectively) located one at each end of said beam.

Inasmuch as the two beam-supports S and S are of substantiallyduplicate construction, a description of one of said beam-supports will suffice for both, and is deemed sufficient for a clear understanding of my present in vention.

The beam-support, in which the essence of my invention resides, comprises, in the preferred form thereof shown in the accompanying drawings, two pairs of beam-clamping members, (designated by C and C, respectively,) constructed and organized to engage the beam B at different points in the length thereof, and a toggle device (designated in a general way by T) carried by one pair of said members and adapted for actuating the two pairs of members simultaneously to effect a clamping action thereof upon the beam, and also adapted for holding said members normally in their elampin g positions. That pair of beam-clamping members which is designated in a general way by C comprises two pivotally-connected spreadable members 2 and 3, which members constitute, in connection with the longitudinal shiftable extension members 2 and 3"earried thereby, the legs proper of the trestle, and that pair of clamping members which is designated by C comprises two parallel members 15 and 16, which are pivotally connected together near their beam-clamping ends and are pivotally connected to the two leg members 2 and 3 at their opposite ends, near the lower ends of said leg members, and constitute beam-clamping members for supporting the beam in advance of the leg members, said members, when the beam-support is in engagement with the beam, being obliquely disposed relatively to the leg members, as will be understood by reference to Fig. 1 of the drawings.

In the form thereof shown most clearly in Fig. 3 of the drawings the upper ends of the leg members 2 and 3 are furnished with inwardly-projeeting beam-grasping prongs 4 and 5, respectively, and are pivotally con nected together at a point somewhat remote from the beam grasping ends by means, preferably, of a link (3, which is pivoted at opposite ends thereof at 7 and '7' to the two leg members 2 and 3. Those portions 8 and 8 of the inner adjacent faces of the two leg members 2 and 3 which are located between the pivotal points of said members and the beam grasping prongs are beveled or inclined with respect to those inner adjacent portions of the leg members located on the opposite side of said pivotal points, so that when the two leg members are spread at their lower ends to bring the beamgrasping ends in clamping engagement with the beam B the adjacent faces of the upper ends will lie in a plane corresponding to the plane of the side faces of the beam and will engage and hold the beam against transverse movement.

The members and 16 are furnished at their ends with inwardly-projecting beamgrasping prongs 17 and 18, respectively, and are pivotally connected together by means of a strap or link 19 in substantially the same manner as are the leg members 2 and 3, and these braces are pivotally connected near their extreme lower ends, as shown at 20 and 20, to the outer side faces of the two leg members 2 and 3, near the lower ends of said members, as will be understood by reference to Figs. 1 and 2 of the drawings, so that as the legs 2 and 3 are spread relatively to each other, as shown in Fig. i, the lower ends of the braces 15 and 16 will be likewise spread at their lower ends and the upper ends of said braces will be brought into clamping engagement with the beam 13 in advance of the clamping-point of the leg members 2 and 3, the braces being, of course, longer from their points of connection with the legs 2 and 3 than are such legs from their points of c011- nection with the braces to the clamping ends thereof.

As a means for facilitating the adjustment of the support vertically the leg members 2 and 3 are preferably constructed to form slideways for the reception of extension members 2 and 3, and said extension members are adjustably supported in the slideways of the leg members 2 and 3 for movement longitudinally thereof, and a clamping device (designated by d) is provided in connection with each leg member for holding the extension member in adjusted position. This adjusting device is shown in the drawings in the nature of a thumb-screw d, having a screwthreaded bearing in the side wall of the leg member and bearing at its inner end against the side face of the extension member.

As a convenient means for spreading the lower ends of the'two pairs of beam-clamping members simultaneously, to bring the upper beam-clamping ends thereof into tight engagement with the beam B, and for holding said members in their beam-clamping positions I have provided a toggle device, (designated in a general way by T,) which, in the form shown in the drawings, comprises two toggle- links 26 and 27, pivotally connected together at their inner ends and pivotally connected at their outer ends to the opposite leg members 2 and 3, respectively, one of said toggle-links having a stop-abutment 27 at the inner edge thereof, adapted for overlapping the upper edge of the adjacent toggle-link to prevent the depression of the two links below the dead-center position, as will be understood by reference to Fig. 2 of the drawings. r

In practice the leg members 2 and 3 will preferably be constructed of channel-iron, and are shown somewhat L-shaped in crosssection, thus forming a light but rigid structure capable of sustaining great weight, and the two braces 15 and 16 will also preferably be constructed of metal, and are shown L- shaped in cross-section. The upper end of each member of the two pairs of clamping members will preferably be bent inward to form a beam-grasping prong, and the prongs thereof are adapted to sink into the wooden beam to firmly hold the same when the lower ends of the clamping members are spread, as shown in Fig. 2.

It will be obvious that the general construction of the two pairs of clamping members may be somewhat modified without departure from my present invention.

By pivotally connecting the brace members 15 and 16 to the outer faces of the leg members, near the lower ends thereof, and by pivotally connecting the two leg members 2 and 3 together by a link, and also pivotally connecting the two brace members by a link near the upper end thereof, it will be seen that the beam-support as a whole may be folded up so that the leg members and brace members will lie in substantially the same plane and close together, as illustrated in Fig. 6, so that the same maybe convenientlytransported for shipment.

\Vhen it is desired to assemble the parts of the trestle, as shown in Fig. 1, the upper ends of the leg members 2 and 3 and the upper ends of the brace members 15 and 16 are spread apart and the beam inserted between them, after which the toggle device will be straightened out, as shown in Fig. 2, which will cause the upper ends of the leg members and brace members to grasp firmly the beam, as shown in Fig. 1, the prongs of said members sinking into the opposite side faces, respectively, of the beam.

From the foregoing it will be seen that the supports may be applied to the beam at any point in the length thereof; that the said supports may be extended to adjust the height of the beam, and that said supports may be applied to any ordinary wooden beam or board without regard to the length or width thereof, provided said beam or board is of the proper thickness.

From the foregoing it will be seen that the leg members and brace members, owing to their peculiar construction and organization, firmly clamp the beam upon the spreading of the lower ends of the leg members by means of the toggle device; that to release the members from the beam it is simply necessary to raise the toggle-links above the dead-center position shown in Fig. 2, and that the use of extraneous clamping devices, such as bolts, screws, &c., is obviated.

Having described my invention, I claim 1. Asupport for atrest-le-beam, comprising two pairs of beam-clamping members, the members of each pair being pivotally connected together near their upper ends and the two pairs being pivotally connected together near their lower ends; and a toggle device in connection with one pair and effective for securing a clamping action of the two pairs simultaneously.

2. In a trestle,the combination with a beam of a pair of extensible legs having beamclamping portions at one end and pivotally connected together near their beam-clamping ends; a toggle device in connection with and effective for spreading the opposite ends of said leg members, to effect a clamping action of the beam-clamping portion; and a clamping-brace pivotally carried by the legs in such manner as to have a beam clamping action simultaneously with the beam-clamping action of said legs.

3. The combination with a trestle-beam,of a pair of pivotally-connected legs havin g beamgrasping prongs at the upper ends thereof; extension members supported for adjustment longitudinally of said legs; a clamping device for holding the extension members in adjusted positions; toggle members in pivotal connection with the lower ends of the legs and effective for spreading the lower ends of said legs to bring the beam-grasping prongs into engagement with the beam; and beam-clamping brace members in pivotal connection with said legs.

4. A support for trestle-beams, comprising two pairs of beam-clamping members pivotally connected together at their lower ends; and means carried by one pair of said members, for effecting a clamping movement of the two pairs of members and for holding said members in their beam-clamping positions.

5. The combination, in a beam-support; of two pivotally-connected leg members having inwardly-projecting beam-graspin g prongs at their upper ends and having beam-bearing faces, between the prongs and pivotal connect-ion of the leg members, which are inclined relatively to those adjacent faces of the leg members located below said pivotal points; and a toggle device pivotally connecting the two leg members near the lower ends thereof and adapted for spread in g the legs at the lower ends thereof, to bring the beam grasping prongs and the bearing-faces into engagement with the beam.

6. The combination, in a beam-support; of two pivotally-connected leg members having inwardly-proj ectin g beam-grasping prongs at their outer ends and having beam-bearing faces, between the prongs and pivotal connection of the leg members, which are inclined relatively to those adjacent faces of the leg members located below said pivotal points; and a toggle device pivotally connecting the two leg members near the lower ends thereof and adapted for spreading the legs at the lower ends thereof, to bring the beam-grasping prongs, together with the inclined bearing-faces, into engagement with the beam.

7. Atrestle-beam supportcomprisingapair of pivotally-connected leg members and a pair of pivotally-connected brace members, which brace members are so organized and pivotally connected to the leg members near the lower ends thereof that they will have a clamping action in unison with the leg members and may be folded up to lie in a plane parallel to the axis of said leg members; and a toggle device in connection with one pair of members, for effecting a clamping and a folding action of the two pairs of members, simultaneously.

8. In a trestle-beam support, a pair of pivotally-connected leg members having longitudinal slideways for the reception of extension members; extension members adj ustably supported in said slideways; clamping devices for holding the extension members in adjusted positions relatively to the leg members; two toggle-links pivotally connected together at their inner ends and pivotally connected at their outer ends to the two leg members, and one of said toggle-links having a stop-abutment for limiting the movement of said toggle-links, and said leg members having beam-engaging prongs at the upper ends thereof adapted to clamp and hold the beam when the toggle-links are in their dead-center positions; and clamping brace members carried by the leg members and having means for engaging the beam, and which brace members are so constructed and organized relatively to the leg members as to have a clamping action simultaneously with the clamping action of said leg members.

CHARLES A. JONES.

Witnesses:

FRED. J. DOLE, HEATH SUTHERLAND.

IIO

Images