Year: 1887

page_text: Date of Application, 14th June, 1887
Complete Left, 6th Mar., 1888
Complete Accepted, 6th Apr., 1888
WILLIAM SHAPTON of 8 Great George Street in the City of Westminster,
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention relates to cranes for working grab buckets.
When working grab buckets it is necessary to provide in addition to the main tackle
by which the grab bucket is lifted and lowered an auxiliary tackle by which the
bucket can be held suspended whilst the main tackle is allowed to become slack.
It is by this means that the delivery of the material from the bucket is effected.
This auxiliary tackle according to my invention consists of a wire rope passing
from the grab bucket over the jib head to a winding drum so controlled that it winds
up the rope whenever it tends to become slack but yields readily to the weight of
the grab bucket. In connection with this drum I provide a brake, and when
it is desired that the bucket should deliver its contents, this brake is applied,
and the drum is held fast. The grab bucket then becomes suspended by the
auxiliary tackle whilst the main tackle becomes sufficiently slack to allow the delivery
to take place.
The mechanism which I employ to actuate the winding of the druin is preferably a
small hydraulic cylinder and ram with pulleys and a wire rope passing around
them. The rope is fast at one end and at the other is wound around another drum
on the same axis with the first. The ram in passing out of the cylinder draws
this rope off the drum causing it to revolve thereby winding up the rope connected
with the grab bucket. In like manner when the grab bucket descends drawing
the rope attached to it from the drum, it winds up the rope encircling the
hydraulic cylinder and ram, and forces the latter into the cylinder against the water
pressure.
It will be observed that a cylinder of small dimensions will suffice to operate the
drum as the ram is never required to support the load but simply to turn the drum
and to wind up the rope when otherwise it would become slack. The brake strap
is tightened upon its drum by means of another hydraulic cylinder; the water

page_text: pressure remains constantly applied on one side of the piston and it is admitted
also to act on the other side so long as the brake is required to remain out of
action.
The brake is applied by relieving the one side of the piston from pressure, leaving
the pressure on the other free to operate. I mount the whole of this auxiliary gear
on a frame which preferably is fixed in an inclined position behind the crane post
so that it serves to some extent as a counterpoise to the load.
Dated this with day of June 1887

page_text: COMPLETE SPECIFICATION.
Improvements in Cranes for Working Grab Buckets.
I, WILLIAM SHAPTON of 8 Great George Street in the City of Westminster,
Engineer, 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 :-
:-
This invention relates to cranes for working grab brackets.
When working grab buckets it is necessary to provide in addition to the main
tackle by which the grab bucket is lifted and lowered an auxiliary tackle by
which the bucket can be held suspended whilst the main tackle is allowed to become
slack. It is by this means that the delivery of the material from the bucket is
affected.
This auxiliary tackle according to my invention consists of a wire rope passing
from the grab bucket over the jib head to a winding drum so controlled that it
winds up the rope whenever it tends to become slack but yields readily to the weight
of the grab bucket. In connection with this drum I provide a brake, and
when it is desired that the bucket should deliver its contents, this brake is
applied, and the drum is held fast. The grab bucket then becomes suspended by the
auxiliary tackle whilst the main tackle becomes sufficiently slack to allow the delivery
to take place.
The mechanism which I employ to actuate the winding of the drum is proferably a
small hydraulic cylinder and ram constantly supplied with water pressure with pulleys
and a wire rope passing around them. The rope is fast at one end and at the other is
wound around another drum on the same axis with the first. The ram in passing out
of the cylinder draws this rope off the drum causing it to revolve thereby winding
up the rope connected with the grab bucket. In like manner when the grab bucket
descends drawing the rope attached to it from the drum, it winds up the rope
encircling the hydraulic cylinder and ram, and forces the latter into the cylinder
against the water pressure.
It will be observed that a cylinder of small dimensions will suffice to oporate the
drum as the ram is never required to support the load but simply to turn the drum
and to wind up the rope when otherwise it would become slack. The brake strap is
tightened upon its drum by means of another hydraulic cylinder which may be
worked in the following manner, the water pressure remains constantly applied on
one side of the piston and it is admitted also to act on the other side so long as the
brake is required to remain out of action.
The brake being applied by relieving the one side of the piston from pressure,
leaving the pressure on the other free to operate or normally the water may
occupy one end of the cylinder being only admitted to the other end when the
brake is to be applied.
In order that my said invention may be most fully understood and readily carried
into effect I will proceed to describe the drawings hereunto annexed.

page_text: DESCRIPTION OF THE DRAWINGS.
Figure 1 is a side elevation of a crane constructed according to my invention.
Figure 2 is a back elevation of part of the same.
a is the grab bucket suspended from the end of the jib of the crane, it is raised
and lowered by the chain which is operated in any convenient manner, the mechanism
for doing this is not shown. c is the auxiliary rope or chain for opening and closing
the bucket, as is shown, it passes over the head of the jib and is fixed to and wound
up on the drum d. The axis of the drum d carries two other drums e and f. The
drum e has fixed to it one end of a rope g which is wound upon it and passes around
pulleys upon a hydraulic cylinder and ram k as shown, the other end of the
rope being fixed to the cylinder. The drum is a brake having the strap passing
around it. One end of the strap is fixed to the hydraulic cylinder m and the other
end is fixed to the piston rod of this cylinder. The area of the piston on the side
farthest from the rod is greater than that of the other side. Normally the brake
strap is kept slack, water being admitted to both ends of the cylinder but the
brake is put on when water is allowed to escape from the larger side of the piston.
The action of the apparatus is as follows
When the grab is being lowered by the chain the rope c is unwound from the
drum d and the rope g is wound up upon the drum e the ram being forced into
the cylinder against the pressure of water. The reverse operations take place when
the grab is raised.
h
When it is desired that the bucket shall deliver its contents, water is admitted
to the piston rod end of the cylinder m the pressure of which, owing to the greater
area of this side of the piston overcomes the pressure on the other side and tightens
the brake strap thereby holding the drums d, e and f. The chain is then allowed to
become slack so that the grab bucket is suspended by the rope c and the delivery
takes place.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what 1
claim is―
1. The auxiliary rope c fixed to and wound upon the drum d to which a constant
tendency is given to rotate and take up slack substantially as described.
2. The drum e upon the same axis as the drum d and the rope g passing around
sheaves upon a hydraulic cylinder and ram constantly supplied with water pressure
for operating the drum d substantially as described.
3. The brake drum fupon the same axis as the drums d and e and the means for
operating it substantially as described.
4. My improvements in cranes for working grab buckets substantially as
described.
Dated this 6th day of March 1888.