IMPROVEMENTS IN MAST HEAD SHEAVES AND FRAMES AND OTHER HOISTING BLOCKS
Year: 1884

page_text: TRUTHIONAB
We EDWARD FIDDIAN JONES of Kensington Street Aston near Birmingham
in the County of Warwick Manufacturer and JAMES PETERKIN of Lossiemouth
in the County of Elgin Mast Maker do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN MAST HEAD SHEAVES AND FRAMES AND OTHER
HOISTING BLOCKS" to be as follows:-
In making the said sheaves and blocks according to our invention we make the
pawl which engages in the hollow ratchet wheel on the sheave or pulley with two
teeth so that the accidental fracture of one of them does not affect the working of
the pawl.
In order to diminish friction we plug the boss of the sheave or pulloy with a
solid lubricant.
For hauling up the jib sail we employ two or more anti-friction rollers turning
on pins fixed in the frame. These rollers are set so that the rope passing over
them has about the same curvature as the sheave or pulley.
Instead of making the ends of the frame wedgo or V shaped as usual we make
the said ends flat. The tendency of the frame to split the mast by the work of
hauling being thrown on the V shaped bottom of the frame is thereby avoided.
We thicken the plates of the frame on their inner sides over the upper part of
the sheave or pulley and over the jib sail rollers and thereby prevent the jamming
of the rope between the sheave or rollers and the said plates. We combine in one
frame the large sheave or pulley for main or fore sail and the rollers for the jib sail
thereby conducing to greater strength in the mast as loss of the mast is cut away
and the whole can be more securely fixed. We put a strengthening boss on the
outer side of the frame around the hole in which the pin is fixed thereby
strengthening the said part.
The improvements which wo have described with reference to a mast head
sheave and frame may be applied to hoisting blocks not fixed to masts.

page_text: 1
COMPLETE SPECIFICATION,
We EDWARD FIDDIAN JONES of Kensington Street,. Aston near Birmingham
in the County of Warwick, Manufacturer and JAMES PETERKIN of Lossiemouth
in the County of Elgin, Mast Maker, do hereby declare the nature of our Invention
for IMPROVEMENTS IN MAST HEAD SHEAVES AND FRAMES AND OTHER HOISTING
BLOCKS and in what manner the same is to be performed to be particularly i
described and ascertained.in and by the following statement :—
"
In making the said sheaves and blocks according to our invention, wo make the
pawl which engages in the hollow ratchet wheel on the sheave or pulley with two
teeth so that the accidental fracture of one of them does not affect the working of
the pawl.
In order to diminish friction we plug the boss of the sheave or pulley_with_a
solid lubricant. -
For hauling up the jib sail we employ-two-or-more-anti-friction-rollers-turning
on pins fixed in the frame. These rollers are set so that the rope passing over
-them-has-about-the-same-curvature as the sheave or pulley.
Instead of making the ends of the frame wedge or V shaped as usual we make
the said ends flat. The tendency of the frame to split the mast by the work of
hauling being thrown on the V shaped bottom of the frame is thereby avoided.
1
We thicken the plates of the frame on their inner sides over the upper part of
the sheave or pulley and over the jib sail rollers and thereby prevent injury to the 2
rope and the jamming of the injurod rope between the sheave or rollers and the
said plates.
We combine in one frame the large sheave or pulley for the main or fore sail
and the rollers for the jib sail thereby conducing to greater strength in the mast
as less of the mast is cut away and the whole can be more securely fixed.
We put a strengthening boss on the outer side of the frame around the hole in
which the pin is fixed thereby strengthening the said part.
The improvements which we have described with reference to a mast head
sheave and frame may be applied to hoisting blocks not fixed to masts.
S
Figure 1 of the accompanying Drawings represents in side elevation and 3
Figure in edge view, a mast head sheave and its frame constructed according to
our invention in which frame are combined the large sheave or pulley for hauling
up the main or fore sail and the rollers for hauling up the jib sail; Figure 3
represents a side elevation of the interior of the sheave with one of the halves of
the frame removed; Figure 4 represents an inside elevation and Figure 5 a vertical 3
section of one of the halves of the frame detached.
The same letters indicate the same parts in Figures 1. 2. 3. 4 and 5.
a is the large sheave or pulley for hauling up the main or fore sail and b, c, d are
the anti-friction rollers for hauling up the jib sail; e, e is the frame of the sheave

page_text: made of two similar shaped plates placed face to face as represented in Figure 2
and rivetted together end to end by pins passed through the snugs e², e³ at the
corners of the said frame. The sheave a turns on the pin or axis fpassed through
the bush g of the sheave, the ends of the said pin or axis f being rivetted on the
outer sides of the plates of the frame e, e. A strengthening boss h is made on the
outside of each of the plates of the frame e e around the hole in which the pin or
axis fis fixed for strengthening the said plate at that part. The interior surface
of the boss g of the sheave or pulley a is plugged with a solid lubricant to diminish
friction. The sheave or pulley a is furnished as usual with the hollow ratchet
whoel i with which the pawl k engages for preventing the rotation of the said
sheave or pulley a in one direction. The said pawl turns on the pin or centre
rivetted to one of the side plates of the frame e. The said pawl k is provided
with two teeth marked ², k³ both of which teeth engage with the ratchet wheel i
as represented in Figure 3. By the use of two teeth in the pawl as represented,
the accidental fracture of one of them does not affect the working of the pulley.
The anti-friction rollers b, c, d for the hauling up of the jib sale turn on pins or
axes b³, c³, d' rivetted to the outer sides of the plates of the frame e, e tho said
rollers being so arranged or set that the rope passing over them has about the
same curvature as the sheave or pulley a. On the inner side of each plato of the
frame is a slightly curved thickening piece or inside cheek m, the said cheeks or
pieces m, m, when the two parts of the frame are fixed together, forming an
arched guard over the upper part of the sheave or pulley a. By the use of the
said arch shaped guard injury to the rope and the jamming of the injured rope
between the sheave a and the said platos of the frame are prevented. The plates e, e
are also thickened at each end near the top as represented at n, n for forming an
arch shaped guard (see Figure 2) at each end of the frame for preventing injury
to the rope and the jamming of the injured rope between the anti-friction
rollers b, c, d and the plates of the frame.
The ends of the frame e, e are flat as represented at e³, e³ for preventing the
frame splitting the mast as herein before pointed out.
We prefer to make the plates of which the frame is composed and the guards of
the same of annealed cast steel.
In place of combining in one frame the sheave or pulley a and the series of anti-
friction rollers b, c, d a "dead sheave" may be substituted for the said anti-friction
rollers as represented in side elevation in Figure 6 and plan in Figure 7, where the
"dead sheave" is marked p and is represented in section in Figure 6. The said
dead sheave p is rivetted to the frame of the sheave.
Figure 8 represents in edge view and Figures 9 and 10 in back and front
elevation a "side sheave" constructed according to our invention; Figure 11
represents a portion of the same in horizontal section.
a is the pulley or sheave provided with the hollow ratchet wheel i and double
toothed pawl, ³, as herein before described with respect to a mast head sheave.
The guard plate 9 (shown separately in Figure 11) of the pulley frame of the side
sheave is strengthened or thickened at its edge marked q² and the durability of
the said guard plate thereby increased.
Figure 12 represents in side elevation Figure 13 in edge viow Figure 14 in
side elevation with a part removed and Figure 15 in horizontal section a "snatch
block" containing our improvement. a is the pulley or sheave of the snatch
block having the usual ratchet wheel i with which is combined our improved
double toothed pawl k, ka, pressed into its acting position by the spring. The
frame of this pulley has two guard plates r,r the edges of which are strengthened
or thickened at to protect them from injury as hereinbefore described with
respect to the side pulley Figures 8, 9, 10 and 11.
The double toothed pawl and the guards represented in connection with the
mast head sheavé represented in Figures 1, 2, 3, 4, 5, 6 and 7 may be used with
mast head sheaves in which the frame carries only the ratchet sheave or pulley.
•

page_text: Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
wo claim is of "Improvements in mast head sheaves and frames and other hoisting
blocks"
First. The combination with the hollow ratchet wheel of the sheave or pulloy
of mast head sheaves and other hoisting blocks, of a double toothed pawl for the
purpose and substantially as herein before described and illustrated in the
accompanying Drawings.
Secondly. In mast head sheaves the combination in one frame of the large
sheave or pulley for hauling up the main or fore sail and two or more anti-friction
rollers or a "dead sheave" for hauling up the jib sail substantially as herein before
described and illustrated in Figures 1. 2. 3 and 6 of the accompanying Drawings.
Thirdly. Thickening the inner sides of the plates of the frames of mast head
sheaves over the upper part of the main or fore sail sheave and over the jib salo
rollers or dead shoave so as to produce guards for preventing injury to and the
jamming-of-the-ropes-substantially as hereinbefore described and illustrated in
Figures 2, 3, 4, 5 and 6 of the accompanying Drawings.
--Fourthly. Making the ends of the frames of mast head sheaves flat for the
purpose and substantially as herein before described and illustrated in Figures 1,
2, 3, 4, 5 and 6 of the accompanying Drawings.
Lastly. Thickening or strengthening the edges of the guard plates of the frames
of side sheaves and snatch blocks and other hoisting blocks as hereinbefore described
-and-illustrated-in-Figures 8 to 15 both inclusive of the accompanying Drawings.-
1