An Improved Sheave for Cranes, Pulley-blocks, and Lifting-tackle.
Year: 1894

page_text: Date of Application, 5th Dec., 1894
Complete Specification Left, 14th May, 1895-Accepted, 17th Aug., 1895
PROVISIONAL SPECIFICATION.
An Improved Sheave for Cranes, Pulley-blocks, and Lifting-tackle.
I RICHARD DONALDSON GLAISTER of 22 Salway Road Stratford in the
County of Essex Mechanic do hereby declare the nature of this invention to be as
follows:-
:―
It is for replacing the ball-weights attached to crane chains by a spring in the
sheave. The sheave is made in two parts, to screw together, working on a fixed
axis. The interior is hollow, and in the box is a spring fastened to the axis, of a
In one of the
power equivalent to the ball-weight it is intended to replace.
hollows, between the lips of the sheave, sunk into a socket so that the ordinary
links will not touch it, is a pin, which its own spring keeps slightly above the
surface. When the chain in going up reaches the point where it ceases to overhaul
itself, a link round which a clip has been placed falls into the socket filling it up
and thus presses down the pin into the box so that it catches the spring in the
same, holding and winding it up as the chain turns the sheave until the load is
taken off, when the spring flies back, and pressing against the pin unwinds the
sheave until the same has carried the chain down to its own overhauling point.
The spring will then slacken, and no longer pressing against the pin, the latter by
its own spring is withdrawn from the box.
A small grooved roller is placed on the outer edge of the sheave to prevent the
possibility of the links slipping.
In the case of a wide sheave or a heavy chain the spring will be double, fixed
outside the sheave one on either side, and attached to the strong back, with a pin
for each pressed into position by a clip on each side of a link lying flat on the lip.
It is intended to apply this invention to fly blocks and gin blocks and to any sheave
which has a chain to be overhauled.
An Improved Sheave for Cranes, Pulley-blocks, and Lifting-tackie.
I RICHARD DONALDSON GLAISTER of 7 Carlton Terrace, Grove Green Road
Leytonstone Essex, Mechanic do hereby declare the nature of this invention and
in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
It is for replacing the ball weights attached to crane chains by a spring in the
sheave. The sheave A of the ordinary size is made in two halves screwing
together and working on the fixed axis C., (see Figs. 1. 2. & 3). The interior of
the sheare is hollow, (see Fig. 2.) and in the box or hollow B, fastened to the said
fixed axis C, is the spring D of a power equivalent to the weight of the ball it is
intended to replace. On the tooth E of the sheave, so placed that the ordinary
links will not touch it, (see Figs. 4 & 5) is the pin F which its own spring keeps
above the surface of the tooth: (see Fig. 4.). When the chain in going up reaches

page_text: the point at which it ceases to overhaul itself, (see Fig. 6.) the link G, arrange 1
as to pass at the overhauling point, and across which the stud H has been placed
(see Fig. 7.) falls on to the tooth E, (see Figs. 7 & 8). The stud H thereupon
presses down the pin F, (see Fig. 8) which in turn catches the spring D in the box,
(see Figs. 8 & 1) and holds the same by virtue of the pressure it exercises against
the lip of the spring D so long as the chain turns the sheave, and until the load is
taken off or the chain is released; (see Fig. 9.) when the spring D, fastened to
the fixed axis C, flies back, and holding the pin F by the pressure it exercises
against it, unwinds the sheave until the same has carried the chain down to its own
overhauling point. The spring D will have then run out and no longer pressing
against the pin F., the latter by its own spring is withdrawn from the box. (See
Fig. 4.) The sinall grooved roller I (see Fig. 1 & 2) is placed on the outer edge
of the sheave to prevent the possibility of the links slipping. K is the crane.
In
the case of a wide sheave or a heavy chain the spring will be double, fixed outside
the sheave, one on either side, and attached to the strong back or the axis with a
pin for each pressed into position by a clip on each side of a flat lying link. It is
intended to apply the invention to fly blocks and to any sheave that has a chain to
overhaul.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that I
claim
That this invention will do away with all necessity for ball weights to chains,
that the spring D inside the sheave worked by the pin F by means of a studded
link so that the chain is brought down to its own overhauling point is an entire
novelty.
Dated this 6th day of July 1895.
RICHARD D. GLAISTER,
7, Grove Green Road, Leytonstone.