US152635A - Improvement in pulley-blocks - Google Patents

Description

B. `HEWITT & S. GUFF.

Pulley-Blocks..

Patented June 30,1874.

in' e..

IJNrrEDA STATES NPATENT OFFICE.

BENJAMIN HEVlTT AND SAMUEL GOFF, OF BIRMINGHAM, ENGLAND.

VIMPROVEMENT IN PULLEY-BLOCKS.

Specification forming part of Letters Patent No. 152,635, dated June 30, 1874; application iiled October 22, 1873.

To alt whom it may concern:

Beit known that we, BENJAMIN Hnwir'r, of Birmingham, in the county of \Varwick, England, pattern-maker, and SAMUEL GOFF, of the same place, pattern-maker, have invented Improvements in Apparatus for Raising and Lowering Veights or Heavy Bodies, ot' which the following is a specication:

The object of our invention is to render a pulley-block more available for the easy lowering of heavy bodies, and for suspending them at any desired height, and this object we attain by combining with an ordinary pulleyblock the braking and arrest-ing devices shown in the accompanying drawing, in which- Figure l is a side view or' the block, with part of the exterior plate removed; Fig. 2 being an edge view of Fig. l. p

The block itself is constructed in the ordinary manner, too well known to need description, and is, in the present instance, provided with two grooved sheaves or pulleys. To the lower end of the pulley-block is loosely hinged an arm, A, composed of two connected plates, a and a', situated, in the present instance, within the frame of the block,` one plate on each side of the pulley B, and between the two plates of the arm, at the upper end of the latter, is loosely hung a brake-blmck, c, which is curved and grooved on its under side to accord with the rope c, where it passes over the pulley B. The movement of the arm is limited by a curved slot, into which a pin, It, on the said` arm projects. A cord, g, is suspended from the brake-block, and a spring, d, is caused to act on the arm for a purpose which will be rendered apparent hereafter.

In hoisting a weight, by pulling the rope c downward in the direction of the arrow l, Fig. l, the brake-block presents no obstruction to the free movement of the rope, and in lowerin g the weight the rope may move freely in a contrary direction without being disturbed by the said brake-bloclg-providing the rope is maintained in a perpendicular position, (shown in Fig. 1,) where it is free from contact with the block and its arm; but if', during the descent of the weight, the rope e is moved to the inclined position shown by dotted lines, so as to bear against the corner w of the block, it will be the means of moving thel latter in the direction ot' the arrow 2, and of bringing the arm in contact with the rope, which will necessarily be jammed between the said block, and the pulley thereby arresting the weight in its descent.

Vhen the lowering of the weight has to be resumed, all that is necessary is to pull the rope downward to a sufficient extent to move the arm and its block back to the position shown in Fig. l, and then permit the rope to assume a perpendicular position, when the weight will descend without interruption.

The spring d has a tendency to force the arm and its block in the direction of the arrow 2, thereby maintaining the block in contact with the hoisting-rope; but the'block may be withdrawn from contact with the rope e by pulling the above-mentioned cord g, on releasing which, however, the hoisting-rope will be at once arrested.

Ve claim as our invention- The combination, with a pulley-block, of the pivoted arm A, acted on by a spring, d, limited in its movements by a pin, h, and slot in the frame, and carrying at its outer extremity a brake-block, c,to which a cord, g, is attached, all as and for the purpose specified.

In witness whereof we have signed our naines to this specification in the presence of two subscribing witnesses.

BENJAMIN HEWITT. SAMUEL GOFF.

Titnesses T. J. ANDREWS,

Cashier, Tcmgz Bros., Birmingham. J. B. GOULD,

U. S. Consul, Birmingham.

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