IMPROVEMENTS IN PULLIES AND PULLEY BLOCKS
Year: 1873

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn
Fields, in the County of Middlesex, Gentleman, for the Invention
of "IMPROVEMENTS IN PULLIES AND PULLEY BLOCKS."- A communication
from abroad by the Firm of Damien and Kister, of Paris, in the
Republic of France.
-
Sealed the 10th June 1873, and dated the 17th April 1873.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson
at the Office of the Commissioners of Patents, with his Petition, on
the 17th April 1873.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County
of Middlesex, Gentleman, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN PULLIES AND PULLEY BLOCKS," a communi-
cation to me from abroad by the Firm of Damien and Kister, of Paris,
in the Republic of France, to be as follows:-
This Invention relates to certain improvements in the manufacture of
pullies and pulley blocks for use on board ships and other places, and
has for its object the increasing their strength and durability by harden-

page_text: ing and preserving the wood of which they are composed, as herein-before
described.
According to this Invention it is proposed to substitute for the hard
and costly lignum vitae hitherto employed for the manufacture of the
sheaves or pullies of pulley blocks other wood of a less costly and more
easily workable nature, by preference beech wood, the body of the sheave
or pulley, and more especially the groove therein, being hardened by the
aid of fire, and subsequently preserved from decay by injecting into the
grain or fibre of the wood any liquid hydrocarbon, whether mineral or
vegetable. The sheave is subsequently covered over the groove with an
annular sheathing of copper, as is well understood.
It is also proposed to harden and preserve in a similar manner the
wood employed in the manufacture of the block or outer case containing
the sheave, and to substitute beech wood for the elm wood hitherto
employed in its manufacture.
The process of injection, which may be effected in any well-known
manner, may be accomplished either before the wood is made into
pulleys or pulley blocks, or after the same have become entirely finished.
Although it is preferred to employ beech wood in carrying out this
Invention, other woods may be used provided they are hardened and
preserved by fire and by hydrocarbon injection, as herein-before
described.
SPECIFICATION in pursuance of the conditions of the Letters Patent
filed by the said John Henry Johnson in the Great Seal Patent
Office on the 16th October 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, Gentleman, send greeting.
2
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventeenth day of April in the year_3
of our Lord One thousand eight hundred and seventy-three, in the
36th year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said John Henry Johnson, Her special

page_text: license that I, the said John Henry Johnson, my executors, adminis-
trators, and assigns, or such others as I, the said John Henry Johnson,..
my executors, administrators, or assigns, should at any time agree with
and no others, from time to time and at all times thereafter during
the term therein expressed, should and lawfully might make, use,
exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
" IMPROVEMENTS IN PULLIES AND PULLEY BLOCKS," a communication to me
from abroad by the Firm of Damien and Kister, of Paris, in the Republic
of France, upon the condition (amongst others) that I, the said John
Henry Johnson, my executors or administrators, by an instrument in
writing under my hand and seal, should particularly describe and ascer-
tain 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 the said Letters Patent.
NOW KNOW YE, that I, the said John Henry Johnson, do hereby
declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained
in and by the following statement, that is to say :-
The said Invention relates to improvements in the manufacture of
ships' pulley blocks and their sheaves or pullies, designated ligno-
metallic pullies, which improvements are based essentially on the means
provided according to this Invention for hardening and preserving tho
wood employed in their manufacture.
Sheaves or pullies formed of wood, and the groove of which is covered
with a copper plate, present, as is well known, many advantages over
the pullies composed of lignum vitæ ordinarily employed; nevertheless
for the sake of economy it is requisite to form them of a cheap wood,
such as beech in particular, which possesses sufficient resistance, and
may be worked with facility.
The employment of this wood however is attended in practice with the
following objections, videlicet:-
First. Beech is a semi-soft wood; the groove of the pulley would be
liable therefore to yield under the pressure of the "falls."
Second. This wood, as is well known decays rapidly, hence the sheave
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113
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page_text: On the other hand the DOCKS or cases of punes are generally man of
elm, which also offers serious inconveniences.
First. It becomes worm eaten and rapidly reduced to dust.
Second. It is easily twisted, split, and broken.
These defects in the sheaves and blocks of pullies are remedied
according to this Invention in the following manner:―
In the first place the body of the sheave and especially the groove is
hardened by the aid of fire. The whole of the sheave is then injected
with a hydrocarburet. Now as the hydrocarburets are powerful anti-
septics the effect of such injection is to ensure the preservation of the
wood for an indefinite period.
In the second place beech wood is according to this Invention substi-
tuted for elm, which is at present employed for the blocks of pullies.
The beech is specially cut up in the direction of the fibre or grain, and
injected in the same manner as the sheave, beech wood being more
susceptible of injection than elm. This operation of injecting the wood
may be effected after the sheave and the block are completely finished,
and consequently it does not entail any inconvenience in the manu-
facture.
.
It is to be understood that I do not limit the application of the
processes herein-before described to the use of beech alone. This wood
is in fact only mentioned in preference to any other because it is less
costly and may be injected better and with greater facility. By this
means therefore there is imparted to the wood which enters into the
composition of ships' pullies, that is to say, the block and the sheave
with copper ferrule, a hardness equal to that of the strongest wood,
and a durability is ensured more than sufficient for all practical
requirements.
The result of these two combined operations is to render the employment
of these pullies in commerce and on board ship wholly practicable, which
result had never hitherto been attained by reason of the inconveniences
herein-before mentioned, which were due to the use in their natural
condition of the elm and beech wood employed in this manufacture.
Under these conditions the sheaves formed by means of special tools,
which however constitute no part of the present Invention, may be
delivered at a price equal to that of the sheaves composed of lignum

page_text: vitæ, and be employed with great advantage in the construction of
pulley blocks or for other purposes on board ship, their durability and
strength rendering them preferable from every point of view to the
latter. Moreover the use of beech, hardened by fire and injected,
completes the advantages lastly herein-before mentioned, and admits of
the manufacture of pullies of every description used on board ship under
the most advantageous conditions as regards durability and strength.
Having now described and particularly ascertained the nature of the
said Invention, and the manner in which the same is or may be used
or carried into effect, I would observe in conclusion that 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 hardening by fire of the wood, and especially of the grooved
part of the sheaves of pulley blocks and its injection with any hydro-
carburet, such as vegetable or mineral oils or essences, substantially as
and for the purpose herein-before described.
Second. The application and use of wood, more especially beech wood,
when the same has been hardened and injected with hydrocarburet, as
herein-before described, to and in the manufacture of the blocks of
pullies.
In witness whereof, I, the said John Henry Johnson, have to
this my Specification set my hand and seal, this Fourteenth day
of October One thousand eight hundred and seventy-three.