US820999A - Block. - Google Patents

Description

A. -B. TA RBOX. BLOCK. APPLIOATION FILED JUNE 24, 1905.

PATENTED MAY 29, 1909.

ALFRED B. TARBOX, OF BOSTON, MASSACHUSETTS.

Specification of Letters latent.

BLOCK.

Patented May 22, 1906.

Application filed June 24, 1905- elial O- 2661755.

To all whom, it may concern.-

Be it known that I, ALFRED B. TARBOX, of Boston, in the county of Suffolk and State of Massachusetts, a citizenof the United States, have invented a new and useful Improvement in Blocks, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming a part of this specification, in explaining its nature.

The special object of my invention is to make a light strong block of simple structure and which can be manufactured at little cost. These objects I attain by making the cheeks of the block and the plate or plates interposed between the sheaves, if there be more than one, out of thin sheet-metal plate stamped or died out in proper form. I-Ieretofore it has been thought insufficient to make these parts, especially the cheeks of the block, out of a single thickness of sheet-metal plate. I have found, however, that by properly combining and otherwise reinforcing the cheeks this may be done and they be strong enough to withstand the rough usage to which a block is ordinarily subjected.

My invention can best be seen and understood by reference to the drawings, in which Figure 1 represents the new form of block in side elevation. Fig. 2 shows the block in front elevation. Fig. 3 shows a vertical section of the block. Fig. 4 shows in front elevation a block containing more than one sheave.

Referring to the drawings, I will describe my invention as applied to the construction of a single sheave-block, as shown in Figs. 1 to 3, inclusive.

A A represent the respective cheeks of the block,whicli aremade each of a single thickness of sheet-1netal plate. The cheeks are spaced apart by separators B to allow for the insertion of the sheave C, which turns upon the usual sheave-pin C. This sheave-pinpasses through the two cheeks and also through the arms of a strap D, carrying the hook D, the arms of the strap being drawn down over the ends of the cheeks, so that they will extend down outside and alongside the same and be secured to the sheave-pin, as before described. To prevent the sheave-pin from turning, it may be provided near its head with a key 0, which fits into a slight hole or recess d, formed in the arm of the strap-bar through which it passes With respect now to the mode of strengthening the checks to stand the strain to which they are subjected it is to be noted in the first place that the cheeks are riveted fast to the separators B, interposed between them. These separators are interposed, preferably, two at the top and one at the bottom end of the cheeks, and the cheeks are united directly to them and to one another by rivets B, which are passed through the cheeks and separators (they being made tubular in form) and then headed. The single thickness of sheet-metal plate is thus bound tight against the ends of the separators, which give adesirable inflexibility to the metal cheeks and very materially strengthen them.

For further strengthening the cheeks each is provided along its outer edge or periphery with an outwardly bent or turned rim a, which at the point a, where the arms of the strap-bar turn around the edge of the cheeks, is cut away to admit of the arms passing down alongside the same, as before described. This turned edge or rim not only acts as a reinforcement preventing the thin metal bending, but it also acts as a guard to prevent the fraying or wearing out of the rope in the operation of the block.

The cheeks are also reinforced or strengthened by the thin metal being bent or pressed outwardly and inwardlyoutwardly by the annular portion a and inwardly at the center by the portion (1 This inwardly pressed center portion by contacting with the hub of the sheave acts as a guard to prevent it from interfering with or wearing against the cheek when turning, and the annular outwardlypressed portion a forms on the inside an annular edge a which acts as a guard adjacent to the periphery of the sheave for preventing the rope becoming displaced from it.

In Fig. 4 I have represented a block containing two sheaves, which is substantially the same structure as before described, with the exception that a flat thin sheet-metal plate substantially oval in shape is interposed between the sheaves. The separators B are interposed between the respective cheeks and adjacent sides of this plate and the whole fastened together by rivets B passing through the cheeks, separators, and interposed plate, then headed in the manner before described. v

Having thus fully described my invention,

I claim and desire to secure by Letters Patent of the United States- I 1. A block of the character specified having cheeks of a single thickness of sheetmetal plate, separators for said cheeks to which they areriveted at the top and bottom, said cheeks also being turned or bent outwardly along the'edge or periphery thereof, a sheave interposed between said cheeks, a sheave-pin and a strap the arms of which are turned to extend down alongside said checks on the outside thereof and be secured to said sheavein substantially as described.

2. A block of the character specified having cheeks of a single thickness of sheetmetal plate, separators for said cheek to which said cheeks are riveted at the top and bottom by rivets extending through the same, said cheeks being turned or bent outwardly along their edges or peripheries and having also outwardly and inwardly bent portions a and a a sheave interposed between said cheeks, a sheave-pin, and a strap the arms of which are turned to extend down alongside said cheeks on the outside thereof and be secured to said sheave-pin substan tially as described.

3. A block of the character specified having checks of a single thickness of sheetmetal plate, two or more sheaves interposed between the same, a fiat sheet-metal plate or plates substantially oval in shape between said sheaves, separators between said cheeks and plate or plates to which said cheeks are riveted at the top and bottom by rivets extending through said cheeks, separators and plates and headed on the outside of said cheeks, said cheeks also being turned or bent outwardly along the edges or peripheries there of, a sheave-pin for supporting said sheave, and a strap the arms of which are turned to extend down alongside said cheeks on the outside thereof and be secured to said sheave-pin substantially as described.

ALFRED B. TARBOX.

Witnesses:

JOHN E. R. HAYES, ROBERT E. BREWER.

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