US2736614A - Trestle assembly - Google Patents

Description

Feb. 28, 1956 Filed June 8, 1953 F. E. BREWSTER, JR

TRESTLE ASSEMBLY 2 SheetsShee1 1 INVENTOR: F'.E.BHEWSTER,JR,

Feb. 28, 1956 E, BREWSTER, JR 2,736,614

TRESTLE ASSEMBLY 2 Sheets-Sheet 2 Filed June 8, 1953 INVENTOR: F1 E..BREW$TER, JR,

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A TTORNE! United States Patent 2,736,614. TRESTLE ASSEMBLY Floyd Emery Brewster, Jr., Los-Angeles, Calif. Application June 8, 1953, Serial No. 360,158-

2 Claims. or. 304 i v The present invention relates to trestles, such as the saw-horses used in the building trades, and. is a continuation in part of my application; Serial No. 2 34,824,filed July 2, 1951, now abandoned.

Originally trestles were made from bars of wood cut to size and nailed together, but'many attempts have been made to provide means for'more quicklyand' securely fastening the wooden parts of the trestles together. It would appear, however, that such devicesas have been developed have not been found entirely satisfactory since very few such devicesh'ave ever reached the market, at least so far as I have been able to ascertain. It is, inview of the foregoing, the object of the present invention to provide very simple and'inexpensive trestle'assembling m ans in the f m o a pair f br cket w i are Shaped to receive the various parts of the trestle or saw-horse and rigidly to maintain these parts in assembled position without having to resort to'the use of ils or oth'er'devices for locking the brackets i'n'positi'on' n the legs, asin the case of trestles now found on the rket. Another. object is to provide in combination wit ch trestle. brackets simple and convenientlyoperated m s for rig ly lopking the trestle parts and the brackets t ether. further object is to provide means for reinforcing the trestle assembly to the end 'that' all danger of relativesh ifting, of the parts thereof,"wh'en the trestle is subjected td heavy pressures, may be eliminated. "With these andotherobjects in view the'inve'ntion'consistsi in the combinations hereinafter fully describ'e'd'and' reference is invited to the accompanying drawings in which preferred forms of the invention are illustrated.

In he drawin s:

Fig. -1 is n r peqits. Vi w at saw-h bracket bodying the invention and showing in skeletonized outline cooperating parts of the saw-horse;

Fig. 2 is an end view showing one end of a saw-horse placed in upside-down position for assembling purposes;

Fig. 3 shows one of the members which combine to form the bracket of Fig. 1;

Fig. 4 illustrates a somewhat modified form of bracket assembly;

Fig. 5 is a cross-sectional view taken through the vertical center of the assembly of Fig. 4; and

Figs. 6 to 8 illustrate further modifications of the bracket assembly.

The device of the invention, in its simplest form, consists of a frame or bracket 1 which is shaped for insertion therein of legs B, C, as indicated in broken outline in Fig. l of the drawings. A recess 2 is sunk into the upper edge of the bracket of a size to receive therein a piece of timber, A, against which the top edges of the legs come to rest when the legs are completely seated in the bracket. This piece of timber forms the top rail of the trestle.

The assembling operation may be greatly facilitated by doing the work with the parts in upside-down position, as indicated in Fig. 2. The top rail A is first set on edge on the ground, or any floor surface, and the bracket is placed in upside-down position thereon to straddle the upper edge "ice of the rail. As indicated in the drawings, the recess 2 is somewhat flared. This is done in order to insure a tight grip on the rail. The lumber used in building operations willvary'in thickness and when the recess is flared and at the bottomno wider than the thinner lumber ordinarily used, it is found that therail will be tightly seated therein. Had the recess been rectangular and of a width to receive the various thickness ordinarily found in building material the rail would, in most cases, not be tightly supported and any side thrust against the saw horse would tendto dislodge. it. The legs are thereupon caused to slide into the bracket until arrested. againstthe sides of the rail. In seating the legs, it is. merely requiredto take care that theouter surfaces of theleg's are held against the inner surfaces of the inclined bracket side members 4, 4 to insure correct" position of the legs. The straight bottom surfaces 2*, 2 of the recess 2 will maintain the bracket squarely seated on the rail. A brace 3, which may be a strip ofwood of any desired length and of the proper width, is then placed between the legs and lightly tapped with a hammer to spread the legs apart and to jam the upper corners of the legs against the sides of the top rail, thereby so rigidly to interlock this trestle assembly that the stresses caused by ordinary use will not affect it. However, a couple of small nails D may be driven through the ends of this brace merely to prevent accidental dislodgm'e'nt thereof by'external causes suchas inadvertently i pm 't e A second bracket is then placed on the top rail and the same assembling operation" is repeated, whereupon the finished trestle or saw-horse is turned over and'isnow ready for use. It will not become shaky or come apart, no matter how hard it is used; And yet itis merely required tq grip one end of-the top rail and to" tilt the trestle, whereuponaqu ick hammer blow will dislodge the brace 3 td'releas'e the legs and frame and to cause these parts to drop to the floor; The legs atthe other end of the trestle are'in like manner disser'iibled. When 'it is considered that surplus pieces of the material usedin ordinary framing of buildings maybe used to form the 1e'g's,'t op rail and bracesof'the trestle, it is seen that I have provided an errtremely'simpl'e, sturdy and dependable device at the mere cost of two "brackets. Each of these brackets consi st ofU- shape 'd side members 4, 4?, which'inay be and preferably are exactly alike and shaped substantially as indicated in Big. 31' When "the two members are 'asss enibled; as indicated in Fig. 1, they may be d or riveted tog'etherf Y Referring now to Figs. 4 and 5, it is noticed that openings are provided in the bracket 10 of a size to receive therein bosses 11, 12, of a plate 13 which is placed on the vertical center line of the bracket. This plate is mounted in position at the time the bracket members first are assembled and will remain rigidly in this position when the parts are welded together as above described. The plate is near the bottom thereof at 13 shown perforated to receive the hook-shaped head 14 of a bolt 15 which extends through an opening of the brace 16. A nut 17 is caused to engage the threads of this bolt rigidly to clamp the parts of the trestle together. When this locking means is added to the assembly of Fig. 1, it is seen that all danger of accidentally dislodging the brace is eliminated. The length of the bolt and the brace 16 should, of course, be calculated to suit the height of the trestle. It is also found that the plate 13 substantially reinforces the bracket which often is subjected to severe end strains while the trestle is in use. In addition, the bottom of the recess 18 may be formed with upwardly pointed prongs 19, which sink into the bottom surface of the top rail A when the trestle is assembled and so materially aid in strengthening the bracket assembly.

The device of the invention as above described forms a very simple, easily and quickly mountable trestle which is entirely dependable in all ordinary cases. There are, however, times when a relatively tall trestle or scaffold is required in which case it is of advantage to add to the bracket assembly one simple reinforcing element, substantially as illustrated in Figs. 6 and 7 of the drawings.

The bracket assembly of Fig. 1 may remain substantially unchanged but a channeled bar 20 is seated in the recess of the bracket. The bottom surface of this bar is shown centrally recessed and perforated to form a tapering seat for the head 21 of a bolt 22 which extends through the brace 23 in the same manner that the bolt 15 engages the brace 16. A nut 24 serves to clamp the parts together and it draws the channel bar so tightly into the recess of the bracket that it forms a long, rigidly fixed seat for the top rail. If desired, perforations may be cut through the bottom plate of the channel and a few nails may be driven through these perforations to prevent longitudinal dis placement of the top rail within the channel. Or, if preferred, perforations 30 may be cut through the bottom of the channel in position to and of a shape to receive therein a series of bracket projections 25 which are similar to the prongs 19 illustrated in Fig. 4.

This trestle assembly contains few simple, inexpensive parts which may be quickly assembled without having to resort to the use of tools and the parts of which when again disassembled, can be bundled together into a very trim package. It is also possible permanently to combine the channel with the bracket by welding these parts together and this operation may be facilitated, substantially as shown in Fig. 8, by bending the portions of the bracket which were cut away to form the recess thereof into outwardly directed ears 32-33. A spot welding operation applied to these ears will then suflice effectively to combine the channel with the bracket. The height of the trestle and scaffold would determine the length of the channel and of the clamping bolt, and when these parts are correctly proportioned, it is found that a structure of sufiicient strength and rigidity for all ordinary trestle or scaffold operations may be provided for ready assembly by the person making use of the device.

I claim:

1. In a trestle having inwardly inclined legs and a top rail, a bracket comprising two identical inwardly opening channel-shaped guides for the legs of the trestle, the upper edges of the bracket being recessed to form a horizontal centrally positioned seat for the top rail, there being vertically alined centrally positioned perforations in the bracket below the top rail seat thereof, a plate having bosses seated in said perforations to lock the plate in posi- 'tion within the bracket, a brace placed between the legs of the trestle below the bracket, and means detachably interconnecting the plate and brace, said means being adjustable to press the brace against the legs thereby to clamp the trestle parts together.

2. In a trestle havinginwardly inclined legs and a top rail, a bracket comprising two identical inwardly opening channel-shaped guides for the legs of the trestle, each guide consisting of a rectangular plate resting against the outer leg surface and flanges inwardly directed therefrom, the flanges of the guides being substantially of a width to cover the side surfaces of the legs on which the guides are seated, the lower inner portions of the flanges being extended inwardly horizontally to overlap each other, means for rigidly combining the overlapping extensions of the two guide flanges, the upper horizontal edges of the flange extensions forming a seat for the top rail, the inner edges of the flanges above said rail seats being upwardly flared, the overlappingextensions of the flanges having vertically alined centrally positional perforations therethrough, a plate having bosses seated in said projections to lock the plate in position within the bracket, a brace placed between the legs of the trestle below the bracket thereof, a bolt detachably seated in said plate and downwardly extending therefrom through said brace, and a nut engaging the lower end of the bolt to press the brace against the trestle legs thereby to spread the legs and rigidly to clamp the trestle parts together.

References Cited in the file of this patent UNITED STATES PATENTS 128,332 Smith June 25, 1872 183,052 Harvey Oct. 10, 1876 362,914 Zeigler May 10, 1887 462,581 Peck Nov. 3, 1891 1,243,532 Krieger Oct. 16, 1917 1,656,558 Dysinger Ian. 17, 1928 2,096,668 Brown Oct. 19, 1937 2,105,979 Manley Ian. 18, 1938 2,132,285 Brown Oct. 4, 1938 2,244,963 P011 Jan. 10, 1941 2,376,153 Karow May 15, 1945 2,545,767 Dalton Mar. 20, 1951 2,561,864 Hollywood July 24, 1951 2,647,803 Bohn Aug. 4, 1953 FOREIGN PATENTS 928,838 France Ian. 8, 1948 632,047 Great Britain Nov. 15, 1949

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