IMPROVEMENTS IN THE CONSTRUCTION OF SHEAVES FOR BLOCKS
Year: 1852

page_text: LETTERS PATENT to Archibald Brown, of Glasgow, in the County
of Lanark, North Britain, Block Maker, for the Invention of
"IMPROVEMENTS IN THE CONSTRUCTION OF SHEAVES FOR BLOCKS
Sealed the 23rd March 1853, and dated the 4th October 1852.
PROVISIONAL SPECIFICATION left by the said Archibald Brown
at the Office of the Commissioners of Patents, with his Petition,
on the 4th October 1852.
I, ARCHIBALD BROWN, of Glasgow, in the County of Lanark, North
Britain, Block Maker, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN THE CONSTRUCTION OF SHEAVES FOR BLOCKS"
to be as follows:-
Whereas the bushes or iron or brass bearing surfaces of the axes of
ships blocks have hitherto been placed in and attached to the wood of
the sheave by means of lateral rivets passing through the bush and
into or through the sheave itself. Now this Invention relates to an
improvement on this system of fastening, by fixing the bush in the
wood by means of lead or other suitable metal or compound poured
into an annular or other circumferential space round the bush when

page_text: placed loosely in the central bore of the sheave. The bush may be
made of various sections externally, such as a square or cylinder,
slightly notched, in order to afford a secure hold to prevent the bush
from turning round in the sheave; and if lead or tin or other soft
holding metal is used it is intended to drill one or more small holes
transversely through the metal of the bush, so that when the holding
metal is poured in to surround.the.bush a portion.of.such.holding metal
will penetrate into the holes so drilled. By this plan not only is the
hold of the bush made more secure, but some portion of the soft metal
being brought into contact with the axle of the sheave; the friction on
the latter will be reduced by the rubbing of the soft metal. The chief
object of the plan being to do away with the necessity of riveting,
this system of holding the bush without rivets may be variously
modified to secure a similar.end. For example, some cements or com-
positions may be passed into the space between the outside of the bush
and the interior of its seat in the sheave, so that on the hardening of
the material the bush will be firmly held.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Archibald Brown in the Great Seal Patent Office,
on the 1st April 1853.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
ARCHIBALD BROWN, of Glasgow, in the County of Lanark, North Britain,
Block Maker, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fourth day of October, in the year of
our Lord One thousand eight hundred and fifty-two, in the sixteenth
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said Archibald Brown, Her special licence that I,
the said Archibald Brown, my executors, administrators, and assigns, or
such others as I, the said Archibald Brown, my executors, administra-
tors, or assigns, should at any time agree with, and no others, from
time to time and at all times thereafter during the term therein ex-
pressed, should and lawfully might make, use, exercise, and vend.

page_text: within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN THE
CONSTRUCTION OF SHEAVES FOR BLOCKS," upon the condition (amongst
others) that I, the said Archibald Brown, by an instrument in writing
under my hand and seal, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to
be performed, and cause the same to be filed in the Great Seal Patent
Office within six calendar months next and immediately after the date
of said Letters Patent.
NOW KNOW YE, that I, the said Archibald Brown, do hereby.
declare the nature of my said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement, reference being had to the Drawings here-
unto attached, and to the letters and figures marked thereon (that is
to say):
Whereas the bushes or iron or brass bearing surfaces for the axes of
ships' blocks have hitherto been placed in and attached to the wood of
the sheave by means of lateral rivets passing through the bush and into
or through the sheave itself. Now my Invention relates to an im-
provement on this system of fastening, by fixing the bush in the wood
by means of lead or other suitable metal or compound poured into an
annular or other circumferential space round the bush when placed
loosely in the central bore of the sheave. The bush may be made of
various sections externally, such as a square or a cylinder, slightly
notched, in order to afford a secure hold to prevent the bush from
turning round in the sheave; and if lead or tin or other soft holding
metal is used it is intended to drill one or more small holes transversely
through the metal of the bush, so that when the holding metal is poured
in to surround the bush a portion of such holding metal will penetrate
into the holes so drilled. By this plan not only is the hold of the
bush made more secure, but some portion of the soft metal being
brought brought into contact with the axle of the sheave, the friction.
on the latter will be reduced by the rubbing of the soft metal. The
chief object of my Invention being to do away with the necessity of
riveting, this system of, holding the bush without rivets may be

page_text: variously modified to secure a similar end. For example, some
cements or compositions may be pressed into the space between the
outside of the bush and the interior of its seat in the sheave, so that on
the hardening of the material the bush will be firmly held.
And in order that my said Invention may be properly understood
I shall now proceed to describe the several Figures on the Sheet of
Drawings hereunto attached. Figure 1, on my Sheet of Drawings is a
complete side elevation of a block sheave detached, and Figure 2, is a
transverse sectional elevation of the same, corresponding; Figure 3, is
a side view of a detached brass or gun metal bush of a different form to
that shewn in Figures 1, and 2, and of a larger size; and Figure 4, is an
end elevation of the bush; Figure 5, is a side view of another form of
bush and Figure 6, is a corresponding end view of the same.
In coll
structing sheaves of this kind a hole somewhat larger than the bush A,
is cut or formed in the centre of the sheave, and the bush, which is
in this instance octagonal in transverse section to prevent revolution in
its seat or separate from the sheave, is then placed in the centre of the
aperture, and tin, lead, or other soft metal B, is then poured into the
annular space left between the outside of the bush and the sheave
itself. As delineated in Figures 1, and 2, the hole in the sheave is
square, so that the metal seat B, cannot revolve in the sheave, neither
can this metal seat move laterally by reason of the central recess or
annular groove c, which is cut in the sheave and receives the retaining
metal or seat B, when the latter is poured in, thus forming a retaining
band or zone upon the outside of the seat B; similarly, lateral motion is
prevented between the bush A, and the metal B, by slightly recessing
the external surface of the bush in the centre. The sheave is finished
up to a flush surface by turning down the superfluous metal, so as to pre-
sent a clean face on each side. In Figures 3, and 4, the bush is hexa-
gonal in transverse section with a curved recess, as in Figures 1, and,
2, to prevent lateral motion. In Figures 5, and 6, the bush is also:
hexagonal in transverse section, but it has, a cylindrical recess in the
centre of its length externally to prevent lateral motion. The inside
hole of the bush is intended to be bored smoothly out, also the
iron pin to be smoothly turned or ground upon a fine stone, thereby

page_text: reducing the amount of friction similar to that of the bushes and
journals of machinery. It is also intended to have a hole bored in the
shell of the block in such a manner as to admit of oil being passed
through to the pin and bush, without requiring to take off the strap
of the block. The bushes may be made of various substances or com-
positions, such as flint, glass, horn, bone, or other hard substance.
The flanges on the bush may also be put into the sheave to rest firmly
on the wood, and the composition of lead, tin, zinc, or other substance
may be poured into one of the apertures so as to fill up the internal
space, thereby making the bush so firm as not to revolve round the
sheave, or come out from either side of the sheave.
Having now described and particularly ascertained the nature of my
Invention, and the manner in which the same is or may be used or
carried into effect, I may observe, in conclusion, that I do not confine or
restrict myself to the precise details or arrangements which I have had
occasion to describe or refer to, as many variations may be made therefrom
without deviating from the principles or main features of my Invention;
but what I consider to be novel and original, and therefore claim as the
Invention secured to me by the herein-before in part recited Letters
Patent, is, First, the system or mode of fitting or attaching the metal
bushes of block sheaves to such sheaves by means of a moulded seat of
metal, cement, or composition, as herein-before described. Second, the
application and use of a moulded retaining seat for the bushes of block
sheaves. Third, the system or mode of preventing lateral longitudinal
or rotatory movement between the bushes of block sheaves and their
retaining seats, and between the retaining seats and the sheaves them-
selves, by interlocking the contact surfaces together.
-
In witness whereof, I, the said Archibald Brown, have hereunto
set my hand and seal, this Thirtieth day of March, in the year
of our Lord One thousand eight hundred and fifty-three.