IMPROVEMENTS IN DIFFERENTIAL PULLEY BLOCKS 33
Year: 1883

page_text: LETTERS PATENT to William Thomas Eades of Birmingham in the county of
Warwick Manufacturer for an Invention of "IMPROVEMENTS IN DIFFERENTIAL
PULLEY BLOCKS
33
PROVISIONAL SPECIFICATION left by the said William Thomas Eades at
the Office of the Commissioners of Patents on the 8th August 1883.
WILLIAM THOMAS EADES of Birmingham in the County of Warwick Manu-
facturer. "IMPROVEMENTS IN DIFFERENTIAL PULLEY BLOCKS."
My invention has reference principally, to the construction and mode of manu-
facturing, what are commonly known as "Weston's differential blocks" and
consists essentially, in making or forming the arms carrying the chain confining or
guiding tubes, for preventing the twisting of the chains. the said arios are fixed
and formed in one piece with the respective sides of the frame, both of the top and
bottom blocks. Which arnis are produced from wrought metal in any desired
way; the frames alone, being usually made from malleable cast iron. By my
method of manufacture pulley blocks are more economically made than hereto-
fore, and considerablo cost incidental in their production is thereby saved.
I will describe my invention as applied to a "Westons' pulley block. And as
the frames, and the parts carried by it of the top and bottoni blocks are essentially
alike, I will only describe the top block.
The pullies of the said top block are mounted and turn on axes in the frame of
the block as usual, the top sides of the frame are prolonged upwards above the
peripheries of the pullies and are attached or connected together by a cross head
rivetted through their respective sides. The other or lower sides of the frame
are prolonged downwards below the pulley peripheries, and are curved or bent
outwards in opposite directions, and carry at their extremities guide or confining
tubes or eyes, cruciform in cross section, and in positions most suitable for the free
running of the chain gearing through them. There is thereby produced with the
framing of the blocks fixed arins carrying at their extremities guiding tubes or eyes,

page_text: for preventing the twisting and regulating the travelling of the chain in paying
out, or hauling in, so that the eyes or openings of the guide tubes on the ends of
the arms being in the same vertical planes as the depressions in the pullies,
determines the perfect parallelism of the chain links in leading to, or passing from
the peripheries of the pullies of the blocks described. In making the cross liead of
the block, the underside (adjacent to the pulley peripheries) are shaped somewhat
to the partial cross section of the links of the chain travelling thereunder, which
acts as an extra guard or leading passage or passages for the links of the chain and
I sink the rivet head of the hook shank inside the said cross head. The frame
and parts carried by it admit of being manufactured or produced by well known
shaping, stamping or pressing processes, which facilitates greatly the various
processes of manufacture in the production of the blocks herein before described.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Thomas Eades in the Patent Office on the 7th February
1884.
WILLIAM THOMAS EADES of Birmingham, in the County of Warwick, Manu-
facturer "IMPROVEMENTS IN DIFFERENTIAL PULLEY BLOCKS
#E
"
"
My invention has reference principally, to the construction and mode of manu-·
facturing, what are commonly known as Westons differential blocks and
consists essentially, in making or forming in the manner herein-after described, the
arms carrying the chain confining or guiding tubes, for preventing the twisting of
the chains. The said arms which are produced from wrought iron, are each
formed in one piece, and together constitute the sides of the frame, both of the top
and bottom blocks; the frames alone being usually made from malleable cast
iron. By my method of construction the frames of pulley blocks are more
economically made than heretofore, and considerable cost incidental to their
production is thereby saved.
I will describe my invention as applied to a Weston's pulley block.
As the frames and the parts carried by it of the top and bottom blocks aro
essentially alike, I will only describe the top block.
The pullies of the said top block are mounted and turn on an axis in the frame
of the block as usual, the top sides of the frame being prolonged upwards above
the peripheries of the pullies, and are attached or connected together by a cross
head, rivetted through their respective sides. The other or lower sides of the
frame are prolonged downwards, below the pulley peripheries and are curved or
bent outwards in opposite directions and carry at their extremities fixed guide or
confining tubes or eyes, the openings in the said tubes or eyes being cruciform in
cross section, and in positions most suitable for the free running of the chain
gearing through them. There is thereby produced with the framing of the blocks,
fixed arms, carrying at their extremities guiding tubes or eyes, for preventing the
twisting and regulating the travelling of the chain in paying out and hauling in,
so that the eyes or openings of the guide tubes on the ends of the arms being in
the same vertical planes as the depressions in the pullies, determine the perfect
parallelism of the chain links in leading to, or passing from the peripheries of the
pullies of the blocks.
In making the cross-head of the block, the underside adjacent to the pulley
peripheries is shaped somewhat to the partial cross-section of the links of the chain
travelling thereunder, thereby securing an extra guard or leading passage of
passages for the links of the chain. The rivet head of the hook shank is sunk
inside the said cross head.
The frame and parts carried by it admit of being manufactured or produced by
well known shaping, stamping or pressing processes, thereby greatly facilitating
the manufacture of the said blocks.
I will now proceed to describe with reference to the accompanying Drawings,
the manner in which my invention is to be performed
Figure 1 represents in side elevation; Figure 2 in front elevation and Figure 3
a plan of underside of a differential pulley block of the kind known as Weston's
block containing my improvements; Figures 4. 5. and 6 show separate parts of
the said pulley block constituting my improvements; and Figure 6 represents a
modification of the fixed chain guide tube.
As the upper and lower blocks and parts connected with them are essentially
alike in construction, as far as my improvements are concerned, I will only describe
the npper block.

page_text: The same lettera indicate the same parts in the several Figures of the Drawings.
a, a represent the differential pulleys of the block of the ordinary construction,
and turning upon the axis a²; the said pulleys being carried by the said arms bb,
forming the suspended frame. The said side arms b, b, forming the frame, are
produced from wrought iron by preference by pressing or cutting out operations:
c is the cross head of the frame to which the said arms b, b are rivetted at c*.
The underside of the cross head c, is shaped somewhat to the partial cross section
of the links of the chain, as represented at c³, which parts at c³ act as extra guides
or leading passages for the links of the chain when passing under and engaging
with them; & is the rivet head of the shank of the hook d, which rivet head is
sunk within the said cross head c. The lower sides of the arms of the frame bare
prolonged downwards some distance below the peripheries of the pulleys, and are
curved outwards in opposite directions at 6, 63 as seen in Figure 1, and carry at
their extremities, fixed or rigid guide or confining tubes or eyes b³, 63, the openings
in which, are cruciform in cross section as seen in Figure 3. The positions of the
said guide tubes b³, b³ are most suitable for the free running or passage of the
endless chain through them. The fixed arms 6 constructed as described are cut
out by preference from wrought iron, or are made by stamping, the guide tubes at
their lower extremities being fixed theroto by rivetting or otherwise, so that the
chain guiding tubes have no independent motions but can only partake of the
motion of the frame itself. The fixed guides on the lower ends of the arms b, b
may be made open, as shown in the modification Figure 6. In this modification
the chain can be introduced into the guides laterally, instead of being-threaded-
through them, as is required in the first described guides.
Although I have only shown my improvements as applied to a Weston's
differential pulley block, yet my said improvements are applicable to other
differential pulley blocks
Having described the nature of my invention and the manner in which the
same is to be performed, I claim as my invention,
The improvements in differential pulley blocks herein-before described and
illustrated in the accompanying Drawings that is to say, constituting the
frames of the said pulley blocks of the separate fixed arms b, b²; b, b²; and
of a separato cross head c with the head d of the shank of the hook sunk
therein. The lower extremities of the said arins carrying fixed tubes or
eyes 63, 63; and the cross head having on its underside, grooves or
guides c³, 3; for the purpose and substantially as herein-before described
and illustrated in the accompanying Drawings.
';
In witness whereof, I, the said William Thomas Eades have hereunto set my
hand and seal this fourth day of February, in the year of our Lord, one thousand,
eight hundred and eighty-four.
Witness
MILES E. HUGHES
Clerk to Henry Skerrett
6 Livery Street
Birmingham
WILLIAM THOMAS EADES (LS.)