IMPROVEMENTS IN PULLEYS OR SHEAVES, AND PULLEY BLOCKS
Year: 1878

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake,
& Co., Patent Agents, Southampton Buildings, London, for the Invention of
"IMPROVEMENTS IN PULLEYS OR SHEAVES, AND PULLEY BLOCKS." A com-
munication from abroad by the Providence Tool Company, of Providence
Rhode Island, United States of America.
aled the 4th October 1878, and dated the 15th August 1878.
COMPLETE SPECIFICATION filed by the said William Robert Lake at the
Office of the Commissioners of Patents on the 15th August 1878.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN PULLEYS OR SHEAVES, AND
PULLEY BLOCKS." A communication from abroad by the Providence Tool Com-
pany, of Providence, Rhode Island, United States of America.
Figure 1 is a perspective view of an improved block sheave, constituting one
part of the said Invention, and Figure 2 is a sectional view through the centre of
the same..
This part of the said Invention consists in casting pulley or sheave with two
sets of spokes, extending from the hub to the concave rim, so that the spokes form
braces arranged to sustain the sides of the concave rim, and thus strengthen the
same, as will be more fully set forth herein-after.
'
In Figures 1 and 2 a is the hub; b, the concave rim; and c, c, are the spokes.
The hub a is slightly longer than the width of the concave rim b for the purpose
of allowing the sheave to turn freely in the block. The spokes c, c, extend from
the two ends of the hub, and, slanting inward, unite with the concave rim, so as
to form firm braces, one opposite the other, leaving the central portion of the rim
free from direct strain, thus allowing the concave rim to contract in cooling without
placing the metal into tensión by which in cold weather, or when receiving a sudden
strain, the rim is liable to break, and the sheave made useless.
When a heavy strain is put on a rope resting in a concave rim of a sheave the
greater strain is on the outside portion of the rope, and this strain compresses, the
го

page_text: rope so that a great lateral pressure is exerted on the sides of the concave rim; and
in cast-metal sheaves, as heretofore constructed, the sides of the concave rim
frequently break off, and when so broken the sheave becomes dangerous; first,
because the pieces pressed out are liable to bind the sheave, and prevent its
rotation in the block; and, second, the sharp edges are liable to cut the rope.
In the improved block sheave, shewn in Figures 1 and 2, the sides of the concave
rim are supported and strengthened by the spokes c, c, which are for that purpose
arranged so as to brace inward from the hub toward the sides of the concave rim.
The rim is not liable to give way under the severest strain on the rope.
By this arrangement the strain is more evenly distributed than when the spokes
The metal is also more
are arranged alternately on both side of the concave.
evenly distributed, and the sheave can be more uniformly annealed.
The sheave is stronger, more durable, and lighter than a lignum-vitae sheave of
the same dimensions, and can be made at a greatly reduced cost.
Another part of the said Invention relates [particularly to pulley or tackle
blocks.
Figure 3 is a side view of one of the said improved tackle blocks.
Figure 4 is a vertical section of a single block.
Figure 5 is a sectional view of a double block.
Figure 6 shews the manner of securing the swivelled hook to a double
block.
This part of the said Invention consists in constructing the block frame of sides
made of narrow tapering ribs uniting in a central hub, in which the bearing for
the sheave axle is secured, the axle being fast in the sheave, and turning with the
same in the bearings of the hub, the ends being protected by caps and oil holes
provided to lubricate the bearings; and in the manner of securing the sides
together, and providing becket holes, as also the arrangement of the hooks and the
like, as will be more fully set forth herein-after.
In these Figures. a is the central hub; b, b, are the radial arms made deeper
nearer the hub, as is shewn in Figures 4 and 5; c is the rubber rim of the block
frame; d, d, are the caps protecting the ends of the sheave shafts. E is the sheave;
ff, the becket holes arranged with raised edges to give a firm bearing to the
same; g is the stirrup in which the hook h is secured, and in which it may freely
turn.
This stirrup is shewn in Figure 3 arranged for a single sheave block, and in
Figure 5 for a double sheave block.
When a loose hook or eye is to be secured to the block frame the stud m, arranged
to enter the bosses i, i, is placed between the same, as shewn, and secured by a
bolt or pin.
A stud arranged as the stud m, shown, not only adds strength to the connection,
and makes the same more rigid, but the bolt, pin, or rivet is released from strain,
and the link is more firmly secured.
In a double or triple block the partition frame is provided with projecting bosses
,, into or under which the stirrup passes, so that the stirrup and hook will be
firmly maintained in the proper position, as is shewn at n.
By the peculiar arrangement of the radial arm b by which the central hub is
secured, held, and braced within the rim c, and by increasing the depth of the
radial arms near the hub a light block frame possessing great strength is made
available for use under excessive strain, the upper arms will be subjected to a tensile
strain; the horizontal arms will act as braces, and will be, like the two lower arms,
subjected to compressing strain, and the whole of the rim c to tensile strain, and
so the strain on the sheave will be equally distributed over the whole frame.
The 'becket holes f. f. permit the becket to be so arranged that the blocks in a
tackle can be brought close together, and the tackle can be rove without overhauling
the whole tackle.
To relieve the pins, bolts, or rivets by which the sides are secured together at
the point or points where the hook or link is secured, and where all the strain is

page_text: exerted, such hooks, or the stirrups by which they are secured, are arranged with.
shoulders and constructed to enter the bosses, so that the pins, bolts, or rivets are
relieved from strain, and the frame is held together more rigidly. The central hub
being arranged to form the bearing for the sheave axle, and provided with oil holes,
is made to project outward, and arranged so as to give a long and firm bearing to
the axle, so as to prevent wear, and allow the sheave' to turn freely with the least
possible friction.
Other features of these improvements in tackle blocks are shewn in Figures 7
to 14.
Figure 7 is an end view of part of a tackle block shewing the hinged loop secured
to both sides of the block frame in solid lines, and also when open in broken
lines.
Figure 8 is a side view of part of the block, shewing the latch by which the
hinged loop is secured.
Figure 9 shews the application of the hinged loop to snatch blocks provided with
a hinged portion of one of the side frames, so that a loop or rope can be passed
in the blocks, and over the sheave.
Figure 10 is a side view of a metal frame tackle block provided with a swivelled
hook, and arranged to be used as a snatch block; and Figure 11 is a section of the
same; Figure 12 is a view of the same, showing the hinged piece of the side
frame raised.*
Figure 13 is a side view of a snatch block, to one side of which a chain is con-
nected and arranged, so that the hook on the other end of the chain will lock the
hinged portion of the side frame, and secure the block.
Figure 14 is an end view drawn to an enlarged scale of the locking device,
showing the bevelled studs secured to each side of the frame.
The object of the part of this Invention, illustrated in the Drawings last above
referred to, is to so secure the loop hole to other fastening by which a tackle block,
is suspended or secured that the block may be readily connected or disconnected,'
and that the strain when the blocks are in use may be fairly on the two sides of
the block frame.
This part of the said Invention consists in the arrangement of a hinged loop
secured to one side of the block frame, and arranged to enter when closed into a
slotted projection on the other side in which it is secured by a hinged lock hook,
which, when in place, is secured by a spring bolt.
This arrangement is applicable to a permanent as well as to a snatch block, as
will be seen by reference to Figure 9.
In cast-metal blocks, and particularly in such in which the block frames are made,
so as to combine great strength with lightness, it becomes important that the strain
exerted on the frame should be equally distributed over both sides of the block
frames.
It is also important that a tackle block should be arranged to be instantaneously
connected or disconnected. With the open hook the connection is not sufficiently
secure, and when secured by rope or strap it requires too much time to disengage
the block.
The arrangement shewn in Figures 7, 8, and 9, permanently secures the hinged
loop by the locking hook, and this hook to be instantaneously disengaged is held by
a spring bolt, so that all the parts are firmly secured to the tackle block. They do
not interfere with the free working of the block and cannot be lost. The block
can be quickly secured or released, and is nearly self-fastening. a represents the
block sheave; b.and 6' are the side frames. In Figures 7, 8, and 9, c is the hinge,
in which the hinged loop E is, hinged; d, d, is the slotted projection, into which
the loop E enters; f is the hinged locking hook or bolt, which, passing through
suitable holes both in the projections d, d, and the loop E, secures the said loop E
to the side of the block frame. This locking hook is permanently secured to the
side of the block frame, and may be held in place when locked by various means
but the spring-pressed bolt g, provided with the cap h, which is arranged so that

page_text: when the locking hook or bolt f is entered, the spring-pressed bolt g will enter a
hole in the locking hook, and so hold the same in position, is preferred.
It will be observed that the bent loop E may be readily passed into a chain link
or around a rope, and the block permanently suspended, and also readily dis-
connected.
All strain exerted on the block will be fairly on each side of the two side frames,
and be equally distributed.
When a snatch block is desired, a portion of the block frame above the sheave is
secured by hinges, as shown in Figure 9, in which 62 is the hinged portion, and i, i,
the hinges. By withdrawing the locking hook f, this portion of the side frame may
be raised; and the rope inserted at any part without first inserting the end of the
rope.
Figures 10, 11, and 12, show the application of the same Invention to a swivel
block, and in these Figures, a is the sheave; b and 6¹ are the side frames; 62 is the
hinged portion of the side frame; c is the swivelled hook; d is the locking staple;
f is the locking hook; g is the spring-pressed locking bolt; and h, the cap of the
locking bolt, and i, i, are the hinges. The operations are the same as in the other
block before described.
When a double swivel or link swivel is desired, the staple d is replaced by a
pin secured to the upper part of the neck piece, and arranged to pass through
a hole in the two side frames, and when the locking bolt is passed through a slot in
the pin, the whole is firmly secured, and the double swivel or link swivel will
operate with reference to the hinged piece of the side frame and the direct
strain on the two side frames, exactly in the same manner as the two blocks
above described.
In a snatch block, one of the side frames can only be secured below the sheave,
so as to allow the loop of a rope to be placed on the sheave. When now a log or
other weight is placed on the block, the side frame is liable to be forced against the
sheave. To strengthen the block and prevent the binding on the sheave, the axle
is provided with shoulders, where it enters the side frame, as shewn in Figure 11,
in which K is the axle. With this arrangement the side frames cannot
be forced down against the sheave, and the same may at all times rotate
freely.
Snatch blocks used on frames or in the woods require to be arranged, so that the
block can be readily secured to a tree or the limb of a tree. Such a block is shown
in Figures 13 and 14, in which a is the sheave; b, the side frames; b², the
hinged portion; d, the staple; f, the locking book; 1, 1, the chain; and m,
a yoke.
The chain is secured to an eye on one side of the frame, to which side also the
staple is secured. The hinged portion passes over the staple, and when the
hook is inserted in the staple the block is firmly secured, the strain is exerted
on both the side frames, and the block may be readily connected and discon-
nected.
The yoke m, being more than half a circle, will support the block when the
hook fis disengaged. A plain chain, such as shown in broken lines, may be used
in place of the said chain and yoke, and in either case a cheap and convenient
fastening device is secured.
Having thus fully described the said Invention, as communicated to me by my
foreign correspondent, and the manner of performing the same, I wish it understood
that I claim,
First. A block sheave, in which the concave rim is connected with the hub by
two sets of spokes inclined inward, and set one opposite the other, as and for the
purpose described.
Second. The combination, shown in Figures 1 and 2, with the hub and concave
rim of the spokes, extending from the outer edge of the hub, and inclining inward,
connecting with the sides of the concave rim, leaving the central portion of the

page_text: concave rim unsupported, and arranged to have the spokes placed opposite one to
another, as and for the purpose set forth.
Third. In a block frame, the combination with the central hub, Figures 3 to 5, of
the radial arms, tapering from the hub toward the rim, and the rim arranged, as and
for the purpose described.
Fourth. The combination with the open cast-metal block frame of the becket
holes, Figure 3, arranged in the sides of the frame, as above described.
Fifth. The combination with the open cast-metal block frame of the stirrup,
Figures 3 and 4, arranged for a single block and secured within the bosses, as above
described.
Sixth. The combination with the partition frame of the double block of
the square recessed bosses, arranged to maintain the stirrup in its proper
position, and to relieve the pin, bolt, or rivet from part of the strain, as above
described.
Seventh. A block consisting of the sheave or sheaves, the sides or frames having
an egg-shaped outline, and rim, and radial arms, connecting the central hub with the
rim, and so arranged that all the strain exerted on the sheave or sheaves is
distributed as above described, so as to secure great strength with the least
material.
Eighth. The combination with a cast-metal block of the hinged loop, Figures 7,
8, and 9, arranged to be secured to both sides of the block frame, as and for the
purpose described.
Ninth. The combination with a cast-metal block frame of the hinged loop and
locking hook, as and for the purpose specified.
Tenth. In a cast-metal block, the combination with the locking hook or bolt
of the spring-pressed bolt, Figures 7, 8, 10, and 12, as and for the purpose set
forth.
Eleventh. In a cast-metal snatch block, the axle, Figure 11, provided with
shoulders, and arranged to support the cast-metal sides, as and for the purpose
described.
Twelfth. A cast-metal snatch block, in which one of the side frames is provided
with an eye and a staple, and the other is provided with a hinged portion arranged
to be locked by a hook, as and for the purpose specified.
In witness whereof, I, the said William Robert Lake, have hereunto set my
hand and seal, this Fifteenth day of August, in the year of our Lord One
thousand eight hundred and seventy-eight.
M DAD