improvements in"TACKIO”DIOOKS
Year: 1894

page_text: Date of Application, 28th Sept., 1894-Accepted, 3rd Nov., 1894
improvements in"TACKIO”DIOOKS:
A cominunication from FRANK X. ROUSSEAU, of Detroit, County of Wayne,
State of Michigan, United States of America.
ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex.
Chartered Patent Agent, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer
tained in and by the following statement :-
.1
This invention relates to new and useful improvements in safety tackle-blocks;
and it consists in a certain, construction, and arrangement of parts, as hereinafter
fully set forth.
The object of the invention is to produce a tackle-block that is strong an
and
compact and that is provided with an automatic clutch that, upon the cessation of
pull upon the rope to raise the weight, will grip or bind' the rope to hold in
suspension a load or weight at any degree of elevation. This object is attained by
the mechanism illustrated in the accompanying drawings, in which:-
Figure 1 is a side elevation of a double-block tackle provided with my improved
features, a portion of the shell of the upper or stationary block and the shank of
its hook being broken away to show the location of parts.
'
Figure 2 is an enlarged perspective.view of the eccentric wedge or clamp invertòd,
showing the serrated groove in its under face that receives and binds the rope.
Figure 3 is a central vertical section through the shank of the hook and the
stationary block as taken on dotted line 3 of Figure 1.
"Referring to the letters of reference, A designates the stationary block or shell,
which is made, preferably, of metal and is composed of the side plates B and the
Central dividing-plate C.
DD designate the sheaves, that are located one on each side of the dividing-
plate C; between the side plates B B, and are journalled, on the pintle a that passes
centrally through the plates of the shell and is rivetted therein, as shown in
Figure 3. The lower edges of the plates of the shell are secured by the pin.c that
passes therethrough and through the shank e of the eye b. whereby said eye is
suspended from said pin, the shank of, said eye,b being divided through its centre
to receive the lower edge of the central dividing-plate C thereby securing, said
plate at the bottom against lateral play and holding it centrally in place and also
distributing the weight equally, between or upon all of the plates, as the.draught
comes between each of the side plates and the central plate. The plates of the
shell at their upper edges are secured by the pin d that passes therethrough and
through the bifurcated shank of, the hook F, pivotally coupling said hook to, the
block or shell, the fork of said hook being provided with a groove or regess s
(see Figure 3), that receives the upper edge of the dividing-plate C to secu
against lateral displacement at the top.
"
ידי
it
H designates the gravitating clamping-wedges of which there are two, and which
are provided in, their under faces with a serrated gorge, or groove as shown in
Figure 2: Said wedges are eccentrically pivotted on the più d one on each, side of
the dividing-plate C. The hubs of said wedges, through which the pin d passes,
extend between the, forks, t of the bifurcated shank of the, hook, F, as shown in
Figure 3, and formed upon said.hub is.a projecting arm 1, to which is attached, a
pull-cord o. By making the shank of the hook bifurcated and leaving, forks.it
of sufficient thickness or strength the side plates, B, B can be firmly secured thereto
by means of the rivet d.without any danger of forcing them together or toward
each other so far as to clamp or bind the wedges H H, which would prevent their

page_text: action by gravity after they were once forced away from the rope by the pull-cord o
and by providing the bottom of the bifurcation with a groove s the end of the
middle plate C will always be held equidistant from the side plates B and the
forks t, thus avoiding any possibility of the wedges becoming caught or bound
when the hook is moved upon its pivotal point d. The weighted clamping-wedge
of the clamping device H is formed with a convex periphery, the curve of the
periphery being in an opposite direction to the curve of the sheave. This leaves
the nose or forward end of the weighted portion adjacent to the sheave, while the
opposite.extremity or heel turns upward and away from the sheave: This con-
struction permits the use of any desired size of hoisting-rope. The hub of the
wedges are made thin, so as to pass between the, forkat of the hook, forming a
shoulders, that extends under the ends of said forks so that the body, of said wedges
fill the shell, being equal in thickness to that of the sheaves,,D, above which said
wedges are suspended, the serrated gorge in the wedges registering with the
groove in the sheaves between which the rope K runs, as shown in Figure 3. This
construction of the wedges permits of the plates B B being placed upon the outside
of the forks of the bifurcated shank of the hooks F, which will permit of the use of
wide pulleys between the plates, and at the same time will permit of the groove in
the wedges being thrown to one side sufficiently to register with the groove in the
pulley to bind the rope equally upon all sides, which could not be done if the
wedges were no thicker, throughout than they are between the forks t t..
12343
L.
1
L designates the running block, having the hook M, to which the load to be
raised is to be attached. Said block is joined to the standing block" A by means of
the rope K, which is rove through said blocks over the sheaves therein in the
ordinary manner. By eccentrically mounting the wedges H upon the pin d the
tendency of the body portion of the wedge is to swing downward, which keeps it in
contact with the rope K, passing over the sheave D. The arrangement is such,
however, that when a downward pull is exerted on the hauling end of the rope to
raise the load the wedge will swing outward, permitting the rope to run freely over
the sheave, but at the cessation of pull on said rope the wedge will be drawn inward
and clamp the rope upon the periphery of the sheave with a force proportionate to
the weight of the load, thereby securely supporting the load at any elevation.
Upon the resumption of the pull upon said rope the wedge will swing out, freeing
the rope and permitting the load to again ascend. When it is desired to lower the
weight, a downward pull is exerted upon the cord a drawing down the arm I and
swinging outward the wedge H as shown by dotted lines in Figure 1 thus freeing
the rope K when by slacking away on the hauling end of said rope 'the block. I
will run down, thus lowering the weight. Upon releasing the cord o the wedge will
again clamp the rope and sustain the weight as before described.
In a double sheave-block by the employment of the two independent wedges, as,
shown in Figure 3, the clamping of the rope is made doubly secure, for should one
wedge permit the rope to slip the other one will hold it, and by means of the
eccentric action of the wedges they will clamp ropes of various sizes with the same
efficiency.
It will be understood that this improved safety-clamp may be attached to single
blocks as well as to double blocks, as shown:
This improved tackle-block is especially adapted for supporting swinging scaffolds
used for painting the sides of high buildings and other work of that kind where
the scaffolding requires to be raised and lowered, as by the use of this tackle
the scaffold may be securely supported at any elevation and readily adjusted when
desired.
Having now particularly described and ascertained the nature of this said inven-
tion as communicated to me by my foreign correspondent, and in what manner the
same is to be performed, I declare thaf what I claim is :-
1. In a tackle-block the combination with the shell of a sheave journalled therein
and a hook pivotally secured to the upper end the shank of which hook is bifurcated

page_text: an eccentric clamping device pivotally secured upon the pivotal pin at the top
directly above said sheave and in a vertical line with the axis thereof said clamping
device having a reduced hub for fitting between the forks of the bifurcated shank
and having a lever-arm extending from it in one direction and a weighted portion
extending from it in the opposite direction said weighted portion having an arc-
shaped clamping-periphery the curvature of which is opposite to the sheath and
formed with a nose in normal contact with the hoisting-cable and a free upturned
heel at the opposite extremity said surface being substantially of the same width
as the width of the sheave and, provided with a concave serrated groove said
clamping device being pivotted upon said pivotal pin above the nose of the weighted
portion the construction being such that a pull on said lever-arm may throw
the nose of the clamping device entirely out of contact with the hoisting-cable-
substantially as set forth.
2. A tackle-block comprising the shell consisting of three plates. and three bolts
through them for holding them together two sheaves journalled upon the middle
bolt one upon each side of the central plate a hook pivotally secured upon the
upper bolt the shank of which hook is bifurcated and provided with a groove in.
the bottom of the bifurcation the upper end of the central plate fitting in said
groove two eccentric clamping devices upon said bolt one upon each side of the
central plate each one of which is reduced at the hub to fit between the fork and
the central plate and the main portion being of the same width as the sheave and
consisting of an eccentric segment the curvature of which is opposite to that of
the sheave and the surface provided with a concave spirally-serrated groove to
register with the groove of the sheave and an eye upon the lower bolt the shank
or upper wall of which is divided through its centre to receive the lower end of the:
central plate substantially as set forth.
Dated this 28th day of September 1894.
W. P. THOMPSON & BOULT,
London, Nottingham, Liverpool, and Manchester,.
Agents for the Applicant.