US100709A - Charles f - Google Patents

Description

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CHARLES r. ANNA'N, or BoSToNf, MASSACHUSETTS.

'Leners Para: N 100,709, dated March 15,1870. f

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` The Schedule referred to in these Letters Patent and making part of the same To all whom it may'concern: l

`Be it known that I, CHARLES F. ANNAN, of Boston, in thecounty of Sul'olk, and State o f Massachusetts, have invented `an Improved Pulley Block, of which the following is a full, clear and exact description, reference being had tothe accompanying drawings making part 'of thsspecitication, in which- Figure 1 is a perspective view of my improved pulley-block.

Figure 2is a longitudinal section through the cenl ter ofthe same.

Figure 3is a section through the same ony the line x z of iig. 2. 1

Figure 4 is a a side elevation of one of the sheaves. Myinvention has for its object to produce Va pulleyblock in which the sheave or` sheaves willturn easily in the direction in which they revtllve when a load is beinghoisted, but with considerable friction in the opposite direction, so that when the load is being lowered the rope will not run soleasily, thereby facil-` itating the operation of lowering, and requiring much less Vforce to sustain the Weight of the load than where an'ordinaryublock is employed; and t My invention consists iu'a sheave made in the form of a ring, within which is fitted a disk or wheel which runs upon the central piu` or axle, the disk being providedwithfa ratchet or `toothed wheel, with which l engagcsapawl, by which it is held stationary when the load iswbeing lowered, so as to compel the slieave'to revolvearound the disk, the friction `between the two servingtoiprevent the free revolutionrof the sheave 1 andretard the movement of the rope, while in hoisting 'the sheavefand disk will revolve together, producig no 'more friction than in an ordinary block.

To' enable others skilled inv the art to widerstand and use my invention, l will proceed to describe the manner in which I yhave carried it ont.

In `the said drawings` A represents the block, which is slot-ted for the reception `of' the two sheaves B B, `over which the rope Each of these sheaves is made in the form of a ring, and hastittedwithin it a disk or wheel C, which 1s bored out at the center for the reception of the projectingportionor hub a of a ratchet-wheel, D, which issecured` to the *face of the disk C by screws l), the huba forming a bushing `for the opening in the center of the disk, which runs upon4 the central pin or axle E. When however, the disk O is of metal, the ratchet-wheel will, of course, be formed in one and the same piece therewith.` l g l rlhe ratchet-wheels D D fit into recesses c c in the block A, and are prevented from revolving in one direction by pawls d d, working in the recesses e c, and

secured to afrod, f, which extends through to the outside of the block, where it has secured to it an arm, g, the point of which fits into a notch, h, in the end of a lever, G, pivoted at t' to the cheek or side of the block; and when this lever is moved into the position seen in dotted lines 'in iig.A 1, it will throw the arm to one side, out of the notch, and hold it in this position, thus partially turning the rod and holding `the pawls, against the resistance of their springs 6,' 'u

out of contact with the teeth of the wheels D, for a purpose which will be hereafter described. Any other suitable device may, however, be employed for operating the pawls d d. i

When a weight is being raised, the sheave B and disk C will revolve freely together' in the direction of' the arrow, tig. 3, on the axle E as a center, no more fric-tion being created than in au ordinary block. \Vhen, however, the weight is being lowered, and the sheave is revolved in a direction contrary to the arrow, the disk C is held stationary by its pawl, thusv compelling the sheave to revolve around the disk, the

`friction thus created between the periphery of the disk C and the interior of `the sheave B(which will be in proportion to the weight of the load being lowered) serving` to retard the revolution of the sheave and the movement of the rope, so that the operation is passed around a beam or cleat, the chaiing between `it and the rope will be muc-h `less thanwith an ordinary block.

In hoisting with an ordinary block,where there is nothing to pass the rope around in taking in slack,

considerable lo'ss is experienced each time a new hold of the rope is taken, owing to its slipping back so easily; butv with myimproved block much-of this loss is avoided, owing to the difficulty with which the,

sheave revolves when the rope runs back, while in hoisting, one man can hold a weight to raise which requires several men, and a saving in labor is thus effected. v

XVhen it isv required merely. to lower the all,7 no load being attached, the pawls d d may be raised and held out of contact with the ratchet-wheels D D by moving the lever G to oneside, as before described, when the sheaves will turn freely in either direction on the pin E, as in an ordinary block.

The block A, :is well as the sheaves B and disks C5 its ratchet-wheel D, or its equivalent, and the p21-w1y may be made either of metal 01l Wood, as may be found d, the Whole constructed and applied to a. block, submost desirable. stantally in the manner and for the purpose set forth.

Claim. u CHS. 1*. ABNAN. What I claim as my invention, and desire to secure Witnesses:

byrLettei-s Patent, is P. E. TESCHEMACHER,

The shezwe B, in combination with the diskf), with XV. J. CAMBRIDGE.

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