Convertible Fitting For Pulley

Abstract

A U-shaped fitting for the attachment post of a pulley which enables the post of the pulley to be fitted either with a shackle or with a U-adaptor and pin.

Description

BACKGROUND OF THE INVENTION

This invention relates to pulleys and more particularly to an improved means for attaching pulleys to another part.

Most pulleys, especially those used on sailboats, have a fitting journalled at one end thereof to enable attachment to another part. In the case of sailboat pulleys, the two most common forms are the shackle fitting and a U-shaped fitting with a transverse pin. The shackle is a piece of inverted U-shape that is pinned onto the free end of a post projecting from the pulley. The U-shaped fitting, on the other hand is typically held to the block by a pin having a head which retains the U-member on the pulley. These two forms of fittings are shown respectively in FIGS. 4 and 1a of the drawing and will be discussed herein in greater detail. The body of the pulley is substantially identical regardless of the form of fitting employed.

A frequently encountered problem is the inability to convert from one type of fitting to another with the same pulley or block, since each fitting uses a different type of permanently mounted post. As a result, dealers of such pulleys or blocks must stock an inventory of both types. A purchaser of one type cannot easily convert the block to the other type. Thus, it would be desirable to devise a convertible fitting that would accommodate adaptation to either type of application.

SUMMARY OF THE INVENTION

The present invention provides a conventional shackle-type post projecting from the block to enable direct attachment of a shackle fitting. A separate U-shape member is provided with a hole between its legs which may be fitted over the post upon removal of the shackle. The upstanding legs of the U-shaped member have two spaced sets of vertically aligned apertures, with a pin passing through the lower apertures and a corresponding aperture in the post. The upper set of apertures is spaced above the top of the post and receives a second pin to enable attachment to another part. The U-shaped member may be removed from the post to enable attachment of a conventional shackle.

THE DRAWINGS

FIG. 1 is an elevational view, partly in section of a pulley that incorporates features of the present invention;

FIG. 1a is a partial sectional view of a pulley having a conventional U-fitting, as known in the prior art;

FIG. 2 is a plan view of the U-shaped member of the present invention;

FIG. 3 is an elevational view of the member shown in FIG. 2; and

FIG. 4 is an elevational view of the pulley shown in FIG. 1, with the U-shaped member removed and the shackle fitting attached.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIGS. 1a and 4 illustrate the two alternate types of end fittings for pulleys known in the prior art. In the case of a shackle fitting, as shown in FIG. 4, a pulley 10 has a vertical straight swivel post 12 extending from the top thereof. The swivel post 12 may be fixed in the top of the pulley body or may be journalled therein. A transverse aperture 14 is provided in the post 12 near the free end thereof. A conventional shackle fitting 16 of inverted U-shape is pivotally mounted on the post by means of a removable pin 18 passing through aligned apertures in the legs of the shackle and the post, with the legs straddling the post.

The shackle fitting shown in FIG. 4 is advantageously used in most applications for sailing, such as for attachment to permanent mast and deck fittings having openings of a large enough diameter to accept the width of the shackle 16. Where space is limited, however, or where the aperture in the other fitting is small, the end arrangement shown in FIG. 1a is employed.

The conventional arrangement shown in FIG. 1a comprises a U-shaped member 20 permanently mounted at the top of the pulley 10 by means of a double headed pin 24 journalled in the top of the pulley. The pin 24 allows rotation of the U-member 20 but does not allow for removal of the member without destruction of the pin. The fitting is attached to another part by means of a removable transverse pin 26 passing through aligned apertures in the legs of the U-member.

It may be seen that conversion from one conventional type of fitting to another cannot be easily accomplished, since the respective pulleys are permanently assembled with a permanent end fitting. This causes an inconvenience to the dealer who must stock quantities of blocks having both types of fittings, even though the pulley mechanism is the same. Also a user of a pulley having one of the end fittings cannot convert the pulley to accept the other fitting and must therefore purchase an entirely new pulley.

The present invention overcomes the above problems by providing a unique adaptor that allows conversion of end fittings from one form to another in a safe and reliable manner. As shown in FIG. 1, the adaptor is mounted on a pulley having a shackle post to form a U-member corresponding to the form shown in FIG. 1a. The adaptor may also be removed to allow attachment of a conventional shackle fitting to the post, as shown in FIG. 4.

More specifically, as shown in FIGS. 1-3, the pulley 10 comprises a pair of spaced side plates, of which one is shown at 30, and has a circular sheave 32 rotatably mounted between the side plates, said sheave normally having a groove around the circumference thereof for receiving a line in the usual fashion.

The side plates 30 extend upwardly beyond the edge of the sheave 32 and merge together in the form of a head 34, which provides support for attachment of the end fitting. The head 34 may take several forms, but in the embodiment shown, the end portions of the two side plates have inwardly facing abutment surfaces 36 and 38, with the portions being secured together by a bolt or rivet 40.

The top of the head 34 is preferably solid with a central aperture 42 therein for receiving the post 44. The top of the head is preferably formed of metal and comprises a top wall 46 containing the aperture 42, with opposite edges being bent downward in the form of depending legs 48 and 50 to provide additional support structure between the spaced side plates. The wall 46 may also comprise a second pair of legs or straps, such as 52, extending over the surface of respective side plates to afford additional structural support thereto. The side plates are held together centrally by means of one or more bolts or rivets 54, which also clamp the straps 52 firmly to the side plates.

The post 44 is received in the aperture 42 and has an enlarged internal end 47 of larger diameter than the aperture to prevent the post from pulling out of the head. The enlarged end 47 is also slightly spaced from the rivet 40 and may rest thereon when unattached to prevent the post from falling inwardly through the head. The post 44 extends outward from the head 34 and has a transverse aperture 56 near the end thereof. The aperture receives a pin 59 to enable mounting of a U-adaptor 58 or a conventional shackle, whichever is desired.

As best shown in FIGS. 1-3, the U-adaptor 58 is generally a U-shaped member comprising a base 60 and a pair of spaced upstanding legs 62 and 64. The base 60 has an aperture 66 (FIG. 2) therein sufficiently large to freely accommodate the post 44, such that the base 60 may rest on top of the head 34. In addition, the legs 62 and 64 have a first pair of apertures 68 (FIG. 3) aligned with the post aperture 56 to enable attachment with the pin 59. It will be seen that all of the pins shown herein have a head in one end and a transverse aperture therein at the other end fitted with a removable retainer.

A second pair of aligned apertures 70 is provided in the legs 62 and 64 in a position spaced above the top of the post 44, said apertures receiving a removable pin 72 to enable attachment to another part.

From the foregoing, it may be seen that when a pin fitting is required, the entire structure shown in FIG. 1 is employed. In order to convert to a shackle attachment, the lower pin 59 is first removed, and the U-adaptor 58 is removed and replaced with a shackle 16 as shown in FIG. 4.

Claims

What is claimed is:

1. An end fitting for a pulley wherein the pulley has a projecting post with a transverse aperture therein, said end fitting comprising a U-shaped member having a substantially flat base and a pair of legs extending therefrom, an aperture in said base adapted to be received on said post, a first pair of apertures in respective legs alignable with a transverse aperture of a post, first pin means extending through said first pair of apertures and a transverse aperture, first retainer means for releasably retaining said first pin means in said first set of apertures, a second pair of apertures in respective legs spaced from said base beyond said first set of apertures, second pin means extending through said second set of apertures, and second retainer means for releasably retaining said second pin means in said second set apertures.