US2689154A - Trestle - Google Patents

Description

H. REDLER Sept. 14, 1954 TRESTLE 2 Sheets-Sheet 1 Filed March 28, 1952 INVENTOR- rvfiIP/PV 3 5.2452

BY M ATTORNEY:

H. REDLER Sept. 14, 1954 TRESTLE 2 Sheets-Sheet 2 Filed March 28, 1952 INVENTOR #Awkr X 5245?- ATTORNEY.

Patented Sept. 14, 1954 UNITED STATES PATENT OFFICE TRESTLE Harry Redler, North Castle, N. Y. Application March 28, 1952, Serial No. 279,030

1 Claim. 1

This invention relates to trestles of the type which includes a horizontally disposed beam supported at each of its opposite ends by a pair of diverging legs.

Trestles of the above type are extensively employed by such artisans as carpenters, plasterers, painters, paper-hangers and various other workmen in pursuing their respective trades.

Ordinarily trestles of the above character are so constructed'that their respectively included beams and beam-supporting legs are permanently assembled in a fixed relation to each other with the result that such trestles obviously present extremely difficultstorage and shipping problems because of their excessive space requirements.

An important object of the present invention is to provide an improved trestle which is so constructed as to enable it to be readily reduced to a highly compact unit requiring relatively little storage or shipping space but yet capable of being easily conditioned for use as a sturdy, rigid and dependable piece of equipment to be employed in the above and other fields of endeavor.

Other objects and advantages of the invention will become apparent from the following description when taken in connection with the accompanying drawings, in which- Fig. 1 is a perspective view showing a trestle embodying this invention and illustrating the same as conditioned for use,

Fig. 2 is an exploded view showing in perspective various elements entering into the structure appearing in Figure 1,

Fig. 3 is an enlarged fragmental view taken on line 3--3 of Figure 1 and showing one of the legunits in anchored engagement with the trestle beam,

Fig. 4 is a view similar to that of Figure 3 and showing the leg-unit in open position as when being released from the trestle beam or as when conditioned to'receive such beam incident to the carrying out of the trestle-assembling operation,

Fig. 5 is a sectional view taken on a plane passing transversely through the trestle beam by way of one of the angle brackets included in that beam as one of its components,

Fig. 6 is a view showing in elevation one of the leg-units in a collapsed condition, and

Fig. 7 is a view showing in elevation the legunit of Figure 6 as it would appear from the right therein.

The trestle herein illustrated as embodying the present invention includes a horizontal beam, indicated in its entirety by the numeral I0, and a pair of leg-units which are identical in construction and are each designated as a whole by the numeral II. As will hereinafter more clearly appear, the beam I0 and leg-units II-II are of such construction that they may be quickly and easily assembled, with reference to each other, into a complete trestle ready for use and thereafter disassembled, as occasion may require, to reduce the trestle to a knocked down condition in the interest of convenience in storageor shipment.

Referring to the beam III in detail, it will be noted that such beam includes an angle-iron stringer I2, to the depending flange of which are Welded or otherwise suitably connected a pair of angle-iron brackets I3-I3. These brackets are located relatively near the opposite ends of the stringer I2 and are so disposed that their upper flanges lie flush with the oppositely extending flange of that stringer. To the stringer I2 and its associated brackets I3-I3, there is connected an appropriate wood facing member I4 which is of a length at least equal to and preferably slightly longer than the stringer, the facing member, which is of substantial width and thickness, being provided with a plurality of bolt holes adapted to register with those provided in the stringer and its associated brackets, as will be readily understood from an inspection of Figure 2, so that the facing member may be conveniently anchored in place by a plurality of bolts, of which two are shown most clearly, in Figure 5 and there indicated by the numeral I5. As shown most clearly in Figures 1 and 2, the depending flange of the stringer I2 is provided at each of its opposite ends with a pair of relatively short lock-pins I6, each of which is securely anchored to the stringer flange, as by a press fit therein, and

projects outwardly to a substantial extent beyond opposite faces of said flange as will be readily understood from an inspection of Figures 3 and 4.

Referring to the leg-units II--II, it will be noted that each of them includes a pair of collapsible angle-iron legs I'I-I'l, which, when attached to the beam I2, extend downwardly and outwardly from the beam in a diverging relation to each other, as shown in Figure 1. From that figure it will be noted that the pair of leg-units III I, when attached to the beam I2,

. apparent, of course, that stability of the assembled trestle is enhanced by reason of the above mentioned diverging relationship of the legs I 'I-- I1 and of the leg-units II-I I.

Each of the angle iron legs I1 is so arranged that its included flanges are presented as outer leg-surfaces when the trestle is conditioned for use as shown in Figures 1. Preferably the legs I! are equipped at their lower ends with suitable cushioning elements such as wood blocks l8, which are detachably held anchored between the leg flanges by ordinary screws so as to permit renewal of the blocks if and when such removal becomes necessary. The legs l'l-ll of each leg-unit II are cut on a bevel at their upper ends and are there welded to a pair of clamp plates l9-l9, each of which is provided with a pair of anchor holes 20-20 spaced from each other in accordance with the spacing of adjacent lock-pins lG-IB. In order to lend strength and finish to the legs I l in the vicinity of their junctures with the clamp plates l9, each of said legs is provided with a triangular-shape gusset 2|, as shown most clearly in Figures 1 and 2. The leg-gussets are welded to the edge margins of the respective unbeveled leg flanges and are in turn welded at their inner edge margins to the respective clamp plates I9.

In order that the leg units ll-II may be readily attached to and detached from the beam ill, the legs I! of each of said units are pivotally connected together at their upper ends by a pair of hinge-links 22 and are similarly connected together at points substantially midway of their lengths by a well known type of toggle unit which includes a pair of toggle arms 23. The hinge-links 22 are so pivotally connected to each other at their overlapping ends as to there provide a relatively stiif hinge-like joint and are so pivotally connected at their opposite ends to the legs I I-I'! of the respective leg-units H as to there provide a relatively free hinge-like joint. Here it is to be noted that the hinge-links 22-22 are of such length that they of necessity move from a pronounced oiT-set or broken position, as shown in Figure 4, into only a slightly off-set or broken position, as shown in Figure 3, during such time as the respective leg units ll-H are being attached to the beam II! when conditioning the trestle for use. The slightly off-set or broken position just mentioned in connection with the hinge-links 22 plays an important part under certain conditions, as will hereinafter more clearly appear, in increasing the clamping action which is exerted on the beam In by the legunits ll after the trestle is conditioned for use. Referring again to the toggle arms 23-23, it will be noted that such arms are pivotally connected to each other at their overlapping ends and are likewise connected at their opposite .ends to the legs ll-ll of the respective leg-units ll. Here it is to be observed that the toggle arms 23-23 are of such length that they move from a pronounced off-set or broken position, as shown in Figure 2, into a position of alignment with each other, as shown in Figure 1, during such time as the respective leg-units lI-ll are being attached to the beam l when conditioning the trestle for use. In order that the toggle arms 23-23 may be limited to a position of alignment with each other as they are being moved from broken position, as shown in Figure 2, into locking position, as shown in Figure 1, each pair of toggle arms is equipped with a keeper 24 in the form of a short length of angle iron, one flange of which is pivotally connected to said arms at their over-lapping ends and the other flange of which so overlies such arms as to engage them as they move into alignment with each other.

From the foregoing, it becomes apparent that the trestle embodying this invention may be readily conditioned for use, as shown in Figure 1, by introducing the opposite ends of the beam stringer I2 into the space afforded between the clamp plates l9-l9, as shown in Figure 4, and then, by aid of the toggle arms 23-23, causing the legs I'I-l'l of the leg units I 1- to so move outwardly at their lower ends as to urge their upper ends inwardly, thus causing the clamp plates to move into intimate clamping engagement with the depending flange of said stringer 12. In this connection it will be understood, of course, that as the clamp plates 19-19 move inwardly towards each other, the lock pins Iii-l6, which are carried by the stringer l2, enter the anchor holes 20-20, with which said plates are provided, and there serve to establish a highly efiective interlocking connection between said stringer and the respective leg-units H-l l, the connection thus aii'orded and the aforementioned clamping efiect that is exerted on the depending stringer flange being collectively utilized to insure rigidity, safety and reliability of the trestle as a unitary structure.

Now, after having described generally the manner in which the leg-units lI-ll are clamped to the beam l0, it becomes apparent that since the hinge links 22-22 assume a slight ly off-set position with respect to each other, as when the trestle is assembled as shown in Figure 1, such links are free to adjust themselves to such further slight ofi-set position as might be prompted when a relatively heavy'load is placed on the trestle beam 10 and thereupon so transmitted, by way of the lock-pins [6, to the upper ends of the legs I'l-I'I, as to cause such ends to move downwardly and inwardly towards each other and thereby urge their associated clamp plates I9-I9 into a more intimate clamping engagement with the depending. flange of the stringer [2, especially along its areas of contact with the extreme upper margins of said plates. Aside from the advantage just described in connection with the hinge links 22-22, it is to be further observed that since these links are normally off-set with reference to "each other, they are obviously free to adjust themselves transversely in one direction or the other from their position shown, for example, in Figure 3, in order that a highly effective clamping engagement may be attained as between the clamp plates l9-l9 and the depending flange of the stringer l2 even though the angle iron from which such stringers are fabricated were to vary in flangethickness to a substantial extent within reasonable limits.

From the foregoing description of the trestle herein shown, it becomes apparent that the legunits ll-ll may be readily detached from the beam [0 by simply breaking the toggle arms 23-23 out of their leg-locking positions and thereupon collapsing the leg-units, as illustrated in Figure 6, so that they together with said beam may be conveniently stored, shipped or otherwise transported as a compact unit in knocked down condition.

\J ranged in pairs and protruding from opposite sides of the flange; a pair of metal leg units each comprising a pair of legs, each leg having secured at its top a metal plate extending laterally of opposite sides of the leg and angularly disposed with relation to the leg axis, each of said plates having a pair of openings adjacent its upper edge and of such size and location as to closely engage said pins, said legs being foldably connected intermediate their ends by a hinged toggle unit and at their upper ends closely adjacent said plates by a pair of links pivoted together and to said legs, the length of said links being such that they are movable from a pronounced offset position with relation to each other when the legs are folded to a slightly offset position when said plates are in flange-clamping position, whereby said plates are free to move into tighter clamping position on said depending flange when Weight is applied to the trestle, the interlocking engagement of said plates with said depending flange and said pins providing the only support for said legs relative to said beam.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date Re. 23,097 Imes Apr. 12, 1949 304,207 Langlais Aug. 26, 1884 657,648 Davidson Sept. 11, 1900 872,722 Fravel Dec. 3, 1907 1,261,007 Beardsley Apr. 2, 1918 1,501,088 Anderson July 15, 1924 1,636,342 Whelan July 19, 1927 1,961,760 Hamren June 5, 1934 2,158,939 Hussey May 16, 1939 2,343,557 Johnson Mar. 7, 1944 2,551,062 Skar May 1, 1951 FOREIGN PATENTS Number Country Date 364,291 Great Britatin Jan. 7, 1932

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