Improved Self-sustaining Pulley Blocks.
Year: 1892

page_text: Date of Application, 12th Mar., 1892
Complete Specification Left, 12th Dec., 1892-Accepted, 4th Feb., 1893
PROVISIONAL SPECIFICATION.
Improved Self-sustaining Pulley Blocks.
I THOMAS METCALFE THOMPSON, Pooley Bridge, Westmoreland, Engineer,
do hereby declare the nature of this invention to he as follows:-
My invention relates chiefly to that class of pulley blocks, in use for ropes that
are self sustaining, and are made as follows.-Instead of placing the pulleys side
by side as in ordinary pulley blocks, I place them between two plates of metal or
other material, in a line with one another, passing a bolt through each pulley and
plate, leaving sufficient space between the pulleys for the bolt of strap, as well as
space for the passage of rope. The strap of block is forked and made to fit on
the outside of plates containing pulleys, a bolt passing through strap and plates,
the bolt may be fastned with a nut or pin, and must allow sufficient play for the
plates to work up and down a few inches each way.
Between the forks at the hook end of strap, I fix a wedge of metal or other
material, shaped so that one side will beare against the rope on the pulley when it
is tilted up, also to prevent the other end being tilted up to far. The hook on the
strap may be on a swivel or fixed. On the bolt, outside of plates, that goes
through the pulley over which the hauling part of rope passes; I place a shackle
or eye, or I may make the plates, containing pulleys, with a projection at the end,
so that a bolt may pass through to hold the shackle or eye.
The other pulley block may be an ordinary one. In reaving the rope in the
pulley block, one end is made fast to the eye of the ordinary block, and the
other end passed up from inside and over the pulley farest froin the shackle or
ere, then through the pulley of the ordinary block and up from inside and over
the pulley nearest the shackle or eye.
In lifting a weight with the pulley blocks, the hauling part of rope tilts the
pulley down and remains so, as long as the pull is maintained, on letting go the
hauling part of rope, the pulley tilts up and jams the rope on the pulley against
the wedge and so prevents it runing back.
To lower the weight, the inside of hauling rope is pulled down past the wedge,
or if desired to lower the weight suddenly, a line is made fast to the shackle or eye,
and pulled down.
These pulley blocks may be made with any number of pulleys, to work on the
same principle.
As my improvements are capable of modifications, without departing from the
principle thereof, I do not restrict myself to dimensions, materials, or the precise
formation of my improved pulley blocks.
Dated this 11th day of March 1892.
*COMPLETE SPECIFICATION.
Improved Self-sustaining Pulley Blocks.
THOMAS METCALFE THOMPSON, Pooley Bridge, Westmoreland, 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 :-
My invention relates chiefly to that class of pulley blocks, in use for ropes, that
are self sustaining.
The invention will be described with reference to-the-accompanying drawings.
Fig. 1 shows-sectional view of pulley 'blocks..

page_text: In making, say, a pulley block with two pulleys, insted of putting the pulleys
side by side, as in ordinary pulley blocks; I place them between two plates, B B.
of metal or other material as at A A 1., passing a bolt through the plates and
pulleys at a a., leaving sufficient space between the pulleys for the bolt of the
strap E, as well as space for the passage of the rope K, B B. plates or sides of
pulley blocks, which must be shaped as required. C. strap. The strap is forked and
fits on the outside of plates B B. containing pulleys À A 1. and is secured by
passing a bolt E. through strap and plates.
Sufficient space must be left between strap and plates to allow them to work up
and down casly.
Between the forks of strap, and inside of plates, I fix a wedge, of metal or other
substance, shaped as at D, so that one part will bear against the rope on the
pulley A when it is tilted up, and act as a brake.
The upper part of wedge or brake must have a shoulder M M. Fig. 2. to rest on
the plates at, Fig. 1, to prevent the other end A 1. being tilted up to far when a
weight is lifted.
Fig. 2. shows side and end view of wedge or brake. M M. the shoulders, N. the
brake, which must have a grove to fit the rope on pulley A. Fig. 1.
Fig. 3. shows wedge or brake, fixed between the strap of block with a bolt or
rivet at the shoulder end, and the bolt E. Fig. 1. at the lower end, space must be
allowed between the strap and wedge or brake for the plates or sides to work
freely.
The lower block H. may be an ordinary one.
In reaving the rope in the pulley blocks, one end is made fast to the eye of
pulley H, and then rove as shown at I J K. and L. Fig. 1. L. being the hauling
part.
In lifting a weight with the pulley blocks, the hauling part of rope L. tilts the
pulley down towards L, untill the shoulder of brake D rests on the top of plates or
sides at b, and remains so, as long as the pull is maintained.
On letting go the hauling part of rope L, the pulley A, tilts up and brakes the
rope against the wedge or brake D, and so prevents the weight being lowered.
To lower the weight, the rope at K. is pulled down past the wedge or brake
and pulley A. or if the weight is to be lowered quickly a line F. is made fast to
shackle or eye G, and pulled down, and the weight is released.
These pulley blocks may be made with any number of pulleys to work on the
same principle.
As my improvements are capable of modifications without departing from the
principle thereof, I do not restrict myself to dimensions, material or the precise
formation of my improved pulley blocks.
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 I
claim is ;-
1. The wedge or brake D. fixed between the forks of strap C, so that it will
brake the rope on pulley A. on being tilted by the weight when hauling part of
rope Lis let go, all substantially as described, and shown on the annexed
drawings.
2. The tilting action of plates or sides B B. containing pulleys A A 1. secured
by bolt E, substantially as and for the purpose specified.
3. Arrangement of small line F, on shackle or eye G, for releasing the weight,
or to lower quickly, substantially as specified and shown.
Dated this Tenth day of December 1892.
THOMAS METCALFE THOMPSON.