AN IMPROVED SAFETY TACKLE FOR RAISING AND LOWERING HEAVY WEIGHTS.
Year: 1865

page_text: LETTERS PATENT to Pierre Joseph Jamet, of Paris, in the Department
of the Seine, Householder, for the Invention of "AN IMPROVED SAFETY
TACKLE FOR RAISING AND LOWERING HEAVY WEIGHTS.'
"
PROVISIONAL SPECIFICATION left by the said Pierre Joseph Jamet at
the Office of the Commissioners of Patents, with his Petition, on the 3rd
April 1865.
I, PIERRE JOSEPH JAMET, of Paris, in the Department of the Seine, France,
Householder, do hereby declare the nature of the said Invention for "Ax
IMPROVED SAFETY TACKLE FOR RAISING AND LOWERING HEAVY WEIGHTS," to be as
follows:-
My Invention consists in a novel construction and arrangement of parts of
the hoisting tackle known as pulley blocks. By means of this safety tackle,
the operator whilst raising or lowering the load is enabled to slacken or release
the hold on the faller rope at any time without the necessity of first securing
the rope. The said slackening or letting loose of the rope will instantly bring
the safety tackle into action, which, operating in the manner of a break
upon the rope, will arrest the same, and maintain the load suspended.
The construction of my improved safety tackle is as follows:-The pulleys
of the upper block instead of being placed between the usual two, cheek plates
forming the frame are placed on a pin passing through one end of a pair of plates
forming a beam similar to the beam of a pair of scales. The return pulley over
which the faller rope is passed is placed at the other end of the beam, and the
beam itself is suspended from a bridle formed of two flat bars binged to the

page_text: beam between the two sets of pulleys. To the upper end of this bridle is secured
the suspension hook. The lower block is made as usual, and the rope is passed
over the several pulleys in the lower and upper blocks in the ordinary manner,
except that the return pulley for the faller rope is, as already mentioned, placed
separately at the other end of the beam. Between the bridle is secured the
break block grooved and shaped towards the return pulley to correspond with
the curve formed by the rope. Owing to the weight of the pulley blocks and
rope that end of the beam to which they are attached is depressed, and the
other end with return pulley will be raised and the rope rest against the break
block. The greater the weight suspended from the hoisting tackle the firmer
will be the hold of the break block upon the faller rope. When the weight
or load is being raised the pull or strain upon the rope will depress the return
pulley end of the beam and disengage the rope from the break, but as soon as
the rope is slackened or let loose, whether intentionally or accidentally, the
weight suspended from the other end will immediately raise the return pulley
to the break again and the load will remain suspended in the air.
In order to render my improved tackle available for lowering weights a pall
in the shape of a bell crank is hinged to the pin of the return pulley. One
arm of the pall reaches horizontally to a catch or stop fixed to the bridle, and
thereby prevents the return pulley pressing against the break, and it is kept in
this position by the other arm, which is made heavier and longer, and hangs
down perpendicularly by its own weight. The faller rope after passing over
the return pulley is passed through an eye or ring, formed at the end of the
long arm, and by this means the pall is actuated. As long as the load is to
descend the rope with its pall arm is held perpendicularly or nearly so, but
when it is desired to arrest the descent of the load, the rope is moved in the
direction away from the line of the load, whereby the vertical pall arm is raised
and the other arm lowered and disengaged from its catch, whereupon the return
pulley will immediately rise and press the rope against the break in the
manner described for raising loads.
by the said Pierre Joseph Jamet in the Great Seal Patent Office on the
2nd October 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, PIERRE
JOSEPH JAMET, of Paris, in the Department of the Seine, France, Householder,
send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Third day of April, in the year of our Lord
One thousand eight hundred and sixty-five, in the twenty-eighth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Pierre Joseph Jamet, Her special licence that I, the said Pierre
Joseph Jamet, my executors, administrators, and assigns, or such others as I,
the said Pierre Joseph Jamet, my executors, administrators, and 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 "AN IMPROVED SAFETY TACKLE FOR RAISING AND LOWERING HEAVY WEIGHTS,"
upon the condition (amongst others) that I, the said Pierre Joseph Jamet,
my executors or administrators, by an instrument in writing under my, or
their, or one of their hands and seals, 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 Pierre Joseph Jamet, 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:-
My Invention relates to that description of hoisting tackle, known as pulley
blocks, and it consists in a novel and improved construction and arrangement
of parts by means of which the pulley blocks are converted into self-aoting
safety tackle. In using this safety tackle the faller rope whilst raising or
lowering the load may at any moment be released or slackened without the
necessity of first securing the rope. The weight of the suspended load will
immediately upon the faller rope being released or slackened depress one
end of the tackle, and thereby raising the other end cause the faller rope to
be securely held fast between the return pulley and a stop piece, which together
operate in the manner of a break or clutch box upon the rope. The load will
thereby be maintained stationary in suspension, without the faller rope being
further secured.
In order that my Invention may be clearly understood, and readily carried
into effect, I will now proceed to describe the same, reference being had
to the annexed Sheet of Drawings, and to the letters and figures marked
thereon.

page_text: The pulleys g,
block and load
Fig. 1 is an end elevation of my improved safety pulley blocks or hoisting
tackle; and Fig. 2 is a front elevation of the same; Fig. 3 is a side elevation,
partly in section, of that portion of the pulley block containing the return
pulley and break. The hoisting tackle is composed, as usual, of an upper and
of a lower pulley block, and it is to the upper block that my improvements
are applied. c, is the suspension hook pivotted in the cross piece t, to the
ends of which are secured the plates p, p¹. These parts together form the
frame or bridle, by which, as in all ordinary pulley blocks, the blocks are
suspended. Between the two plates p, p, and fixed upon the central bolt or
axle 1, are placed the two cheek plates j, j', connected with and kept at the
proper distance from each other by the stay bolts n, n¹, n¹¹.
9, 9, supporting by means of the rope X the lower pulley
are fixed upon the bolt on the right side of the plates p, p, and they are
held apart from each other by division plates as usual. The pulley b, over
which the faller rope X¹ passes, and which I call the return pulley, is secured
by the bolt on the left side of the plates p, pl. From the position of the
cheek plates j, j, upon the bolt 1, see Fig. 2, it will be seen that the cheek
plates j, j, can vibrate or oscillate upon the bolt 1, in a manner similar to the
beam of a weighing machine; but the amount of oscillation is limited on one
side by the stop 2, and on the other by the faller rope X¹, passing over the
pulley 6, coming in contact with the cross piece t, which is at the point of
contact grooved to fit the rope, as seen in Fig. 3. When the suspended load
is being raised by pulling at the faller rope X¹ the cheek plates j, j¹, will be
caused to turn round the bolt 7, the pulleys g, g¹, 9", being raised, and the
pulley depressed to a corresponding extent, assume the position represented
in black lines in Fig. 2; but every time the faller rope X¹ is released, or the hold
slackened, the cheek plates j, j', with pulleys, will instantly return to the position
marked in blue lines in Fig. 2, and represented in Fig. 8, where the rope X'
is shown as being compressed and held by the cross piece t. That this force
is sufficient to maintain the load suspended has been practically demonstrated
by experience. It is evident that the greater the weight of the load the
greater also the power of supporting it, the latter increasing at the same ratio
as the weight of the load.
In order to facilitate the rapid lowering of a load when desirable, I use an
escapement pall g, which turns freely upon the bolt . This pall is made with
a long arm, reaching downwards, whose end is formed into an eye or ring
x, through which the faller rope is passed. The upper part of the pall has a
notch or catch e formed upon it. When the pall q is in the position shown in
Fig. 2 the catch e abuts against the cross piece t, and thereby prevents the rope

page_text: D
being pressed against t, and the load can therefore descend freely if the faller
end is liberated. In order to bring the break into action for arresting the further
descent of the load, for instance, it is simply necessary to pull at the faller rope
in the direction shown in blue, in Fig. 2, when the long arm of the pall q
with its eye will be drawn in the same direction, and thereby disengage the
catch e from the piece t, and allow the rope to be again pressed against and
held fast by the stop t, as shown in Fig. 3. It will be seen from the above
that the break power can, at will, be brought into action or out of action by
pulling the faller end of the rope either in the direction shown in Fig. 2, or
in the direction shown in Fig. 3, and in blue lines in Fig. 2, according to the
maximum weight which the safety tackle is intended to support the distance
from the bolt to the bolt, and thereby the leverage for turning the
cheeks j, j, round the bolt 1, in disengaging the rope from the action of the
break is or may be increased. My improved safety tackle can be applied and
actuated whatever the height or elevation at which it be placed, and whatever
the number and the dimensions of the pullies; it possesses therefore a decided
superiority over all similar apparatus hitherto used. My improved safety
tackle is applicable for raising, lowering, holding, and supporting loads and
weights generally, in the pits of mines, on board of vessels, in building and
in renovating or plastering of houses, and for numerous other purposes.
Having now described the nature of my said Invention I wish it to be
understood that I do not confine or restrict myself to the precise details and
arrangements as herein-before described and illustrated in the Drawings; but
what I claim as the Invention to be secured to me by the herein-before in
part recited Letters Patent is,-
Firstly, the making the upper pulley block oscillating in the manner and for
the purposes substantially as described.
Secondly, the application of an escapement pall in the manner and for the
purpose substantially as described.
rope
Thirdly, the application of a return pulley, over which the faller end of the
is passed, in the manner and for the purposes substantially as described.
In witness whereof, I, the said Pierre Joseph Jamet, have hereunto
set my hand and seal, this Sixth day of September, in the year of
our Lord One thousand eight hundred and sixty-five.