Improvements in and connected with Purchase Blocks.
Year: 1897

page_text: Date of Application, 30th Nov., 1897
Complete Specification Left. 30th Aug., 1898-Accepted, 26th Nov., 1898
Improvements in and connected with Purchase Blocks.
.
THOMAS DOWNIE, Roslyn House, Claremont Road, Seaforth, Lancashire, Engineer
& Shipbuilder, do hereby declare the nature of this invention to be as follows:-
The improvement claimed for is that the block is stronger, lighter and
simpler than any in use.
In the design all outside bindings are dispensed with, the sheave and shackle
pins holding all the parts together. The shackle is designed to receive all the
cheek plates, and the pin being bourn the whole length each cheek takes its share
of the weight. The sheave pin is also supported by the cheek plates, between the
sheaves. The only forgings are the pins and shackle, the checks are cut out of best
tested mild steel.
11:00
of November 1907
improvements in aпи сопноси
I, THOMAS DOWNIE, of Roslyn House, Claremont Road, Seaforth, Lancashire,
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 has reference to purchase blocks, that is to say, blocks for raising
and lowering weights-more particularly heavy weights-having a plurality of
sheaves over which the raising or lifting rope or chain passes; and it has for its
object to provide improvements in such blocks by which the ends hereafter specified
are accomplished.
The invention will be described in connection with the accompanying drawings,
which shew my improved block in sectional end elevation-Figure 1, and side
elevation Figure 2.
Referring to the drawings, a is the shackle by which the block is supported or
suspended, and 6 is the shackle pin from which the sheaves, and other parts of
the block are carried. The eye portion of the shackle a is made up of numbers
of parts, a¹, corresponding with the number of sheaves, with spaces or gaps between
them, into which intermediate dividing plates c fit; while the main cheek plates
of the block come outside the eye portions a¹. As will be seen, the shackle pin b
077

page_text: passes through the cheek and dividing plates c¹, c, and through the several eye
parts a¹; and it is thus supported both at the middle and the ends; i.e. practically,
along the whole of its length.
The dividing plates as well as the outside plates or cheeks e-are carried
down and serve to support the centre or sheave pin d at points intermediate the
ends, as well as at the ends; and the sheaves e are mounted and work on portions
of the pin d between the several plates or cheeks.
With regard to the weight which comes upon the block, and different parts,-
firstly, the shackle pin 6 is supported practically for its whole length, the centre
being supported, as well as the ends. Then the sheave supporting plates or
cheeks c care all equally and rigidly supported by this pin 6 and eyes a¹; and
these in turn support the sheave or centre pin d both at the ends and at inter-
mediate points along its length, so that each plate or cheek carries its share of the
weight of the block. By this, the bending of the sheave pin d, and canting of
the sheaves is prevented; and all the sheaves are rigidly supported in their
position, and kept truly on their axle, when the load is on them, as well as when
it is not.
F
The block has no outside bindings, all the parts being held together by the
shackle pin b, and centre pin d; and a block constructed as described and shewn,
for a given weight of material and size, will carry safely, and work efficiently with
a load much in excess of that which can be properly carried by a purchase block
of ordinary construction.
Of course for the lower block of a pair, the block as shewn in the drawings would
be reversed; the centre pin d and sheaves being uppermost, and the pin b and
shackle or hook below.
Having now particularly described and ascertained the nature of this
invention and in what manner the same is to be performed, I declare that what
I claim is:-
1. A multiple sheave purchase block, having a division plate or plates between
the outside cheeks and plates, supported by the shackle or fastener eyes and pin,
and supporting the centre or sheave pin; substantially as herein set forth.
2. The purchase block comprising the shackle or fastener a with eye portions a
a¹ a¹, pin b, division plates c c side plates or cheeks c¹, centre or sheave pin b, and
sheaves e particularly as shewn in and set forth with reference to the drawings.
Dated this 24th day of August 1898.
CHEESBROUGH & ROYSTON,
Applicant's Patent Agents, 15, Water Street, Liverpool.
CHEESBROUGH & ROYSTON,
Applicant's Patent Agents, 15, Water Street, Liverpool.