US476078A - Tackle-block - Google Patents

Description

UNITED STATES PATENT OFFICE.

FRANK X. ROUS SEAU, OF DETROIT, MICHIGAN.

TACKLE-BLOCK.

- SPECIFICATION forming part of Letters Patent No. 476,078, dated May 31, 1892.

Application filed September 28, 1891. $erial No. 407,035. (No model.)

T at whom it may concern.-

Be it known that I, FRANK X. ROUSSEAU, a citizen of the United States, residing at Detroit, in the county of Wayne and State of Michigan, have invented certain new and usefullmprovements in Tackle-Blocks; and I do 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, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form a part of this specification.

This invention relates to new and useful improvements in safety tackle-blocks; and it consists in a certain construction and arrangement of parts, as hereinafter fully set forth,

the essential features of which being pointed out particularly in the claims.

The object of the invention is to produce a tackle-blockthat is strong and compact and that is provided with an automatic clutch that, upon the cessation of pull upon the rope to raise the weight, will grip or bind the rope to hold in suspension a load or weight at any degree of elevation. This object is attained by the mechanism illustrated in the accompanying drawings, in which Figure 1 is a side elevation of a doubleblock tackle provided with my improved features, a portion of the shell of the upper or stationary block and the shank of its hook being broken away to show the location of parts. Fig. 2 is an enlarged perspective view of the eccentric wedge or clamp inverted, showing the serrated groove in its under face that receives and binds the rope. Fig. 3 is a central vertical section through the shank of the hook and the stationary block as taken on dotted line 3 of Fig. 1.

Referring to the letters of reference, A designates the stationary block or shell, which is made, preferably, of metal and is composed of the side plates B and the central dividingplate 0. 1

D D designate the sheaves, that are located one on each side of the dividing-plate C, between the side plates B B, and are journaled on the pintle a, that passes centrally through the plates of the shell and is riveted therein, as shown in Fig. 3. The lower edges of the plates of the shell are secured by the pin a, that passes therethrough and through the shank e of the eye I), whereby said eye is suspended from said pin, the shank of said eye 19 being divided through its center to receive the lower edge of the central dividing-plate 0, thereby securing said plate at the bottom against lateral play and holding it centrally in place and also distributing the weight equally between or upon all of the plates, as the draft comes between each of the side plates and the central plate. The plates of the shell at their upper edges are secured by the pih cl, thatpasses therethrough and through the bifurcated shank h of the hook F, pivotally coupling said hook to the block or shell, the fork of said hook being provided with a groove or recess 8, (see Fig. 3,) that receives the upper edge of the dividing-plate C to sesure it against lateral displacement at the top.

H designates the gravitating clampingwedges, of which there are two, and which are provided in their under faces with a serrated gorge or groove f, as shown in Fig. 2. Said wedges are eccentrically pivoted on the pin d, one on each side of the dividing-plate O. The hubs of saidwedges, through which the pin d passes, extend between the forks t of the bifurcated shank of the hook F, as shown in Fig. 3, and formed upon said hub is a projecting arm I, to which is attached a pull-cord 0. By making the shank of the hook bifurcated and leaving forks t t of sufficient thickness or strength the side plates B B can be firmly secured thereto by means of the rivet cl without any danger of forcing them to gether or toward each other so far as to clamp or bind the wedges H H, which would prevent their action by gravity after they were once forced away from the rope by the pull-cord 0, and by providing the bottom of the bifurcation with a groove 8' the end of the middle plate (J will always be held equidistant from the side plates i3 and the forks 25, thus avoiding any possibility of. the Wedges becoming caught or bound when the hook is moved upon its pivotal point (I. The weighted clamping-wedge of the clamping device H is formed with a convex periphery, the curve of the periphery being in an opposite directionto the curve of the sheave. This leaves the nose or forward end of the weighted portion adjacent to the sheave, while the opposite extremity or heel turns upward and away from the sheave. This construction permits the use of any desired size of hoisting-rope. The hub 'ItOf the wedges are made thin, so as to pass between the forks tof the hook, forming a shoulder s, that extends under the ends of said forks, so that the body of said wedges fill the shell, being equal in thickness to that of the sheaves D, above which said wedges are suspended, the serrated gorge f in the Wedges registering with the groove in the sheaves between which the rope K runs, as shown in Fig. 3. This construction of the wedges permits of the plates B B being placed upon the outside of the forks of the bifurcated shank of the hooks F, which will permit of the use of wide pulleys between the plates, and at the same time will permit of the groovein the wedges being thrown to one side sufficiently to register with the groove in the pulley to bind the rope equally upon all sides, which could not be done if the wedges were no thicker throughout than they are between the forks t t.

L designates the running block, having the hook M, to which the load to be raised is to be attached. Said block is joined to the standing block A by means of the rope K, which is rove through said blocks over the sheaves therein in the ordinary manner. By eccentrically mounting the wedges H upon the pin d the tendency of the body portion of the wedge is to swing downward, which keeps it in contact with the rope K, passing over the sheave D. The arrangement is such, however, that when a downward pull is exerted on the hauling end of the rope to raise the load the wedge will swingoutward, permitting the rope to run freely over the sheave, but at the cessation of pull on said rope the wedge Will be drawn inward and clamp the rope upon the periphery of the sheave with a force proportionate to the weight of the load, there by securely supporting the load at any elevation. Upon'the resumption of the pull upon said rope the wedge will swing out, freeing the rope and permitting the load to again ascend. \Vhen it is desired to lower the weight, a downward pull is exerted upon the cord 0, drawing down the arm I and swinging outward the wedge H, as shown by dotted lines in Fig. 1, thus freeing the rope K, when by slacking away on the hauling end of said rope the block L will run down, thus lowering the weight- Upon releasing the cord 0 the wedge will again clamp the rope and sustain the weight, as before described.

In a double sheave-block by the employment of the two independent wedges, as shown in Fig. 3, the clamping of the rope is made doubly secure, for should one wedge permit the rope to slip the otherone will hold it, and by means of the eccentric action of the wedges they will clamp ropes of various sizes with the same efficiency.

It will be understood that this improved safety-clamp may be attached to single blocks as well as to double blocks, as shown.

This improved tackle-block is especially adapted for supporting swinging 'scafiolds used for painting the sides of high buildings and other work of that kind where the scaffolding requires to be raised and lowered, as by the use of this tackle the scafiold may be securely supported at any elevation and readily adjusted when desired.

Having thus fully set forth my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In a tackle-block, the combination, with the shell, of a sheave journaled therein and a hook pivotally secured to the upper end, the shank of which hook is bifurcated, an eccentric clamping device pivotally secured upon the pivotal pin at the top directly above said sheave and in a vertical line with the axis thereof, said clamping device having a reduced h uh for fittin g between the forks of the bifurcated shank and having a lever-arm extending from it in one direction and a weighted portion extending from it in the opposite direction, said weighted portion having an arc-shaped clamping-periphery the curvature of which is opposite to the sheath and formed with a nose in normal contact with the hoisting-cable and a free upturned heel at the opposite extremity, said surface being substantially of the same width as the width of the sheave and provided with a concave serrated groove, said clamping device being pivoted upon said pivotal pin above the nose of the weighted portion, the construction being such that a pull on said lever-arm may throw the nose of the clamping device entirely out of contact with the hoisting-cable, substantially as setforth.

2. A tackle-block comprising the shell consisting of three plates and three bolts through them for holding them together, two sheaves journaled upon the middle bolt, one upon each side of the central plate, a hook pivotally secured upon the upper bolt, the shank of which hook is bifurcated and provided with a groove in the bottom of the bifurcation, the upper end of the central plate fittingin said groove, two eccentric clamping devices upon said bolt, one upon each side of the central plate, each one of which is reduced at the hub to fit between the fork and the central plate, and the main portion being of the same width as the sheave and consisting of an eccentric segment the curvature of which is opposite to that of the sheave and the surface provided with a concave spirally-serrated groove to register with the groove of the sheave, and an eye upon the lower bolt, the shank or up per wall of which is divided through its center to receive the lower end of the central plate, substantially as set forth.

In testimony whereof I affix my signature in presence of two witnesses.

FRANK X. ROUSSEAU.

\Vitnesses:

Louis 0. OHAPoToN, 0. WHEELER.

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