An Improved Self-acting Pulley Lock (for Gripping and Checking the Run of the Cord at any Desired Point, When Raising or Lowering Weights.
Year: 1896

page_text: An Improved Self-acting Pulley Lock (for Gripping and Checking the
Run of the Cord at any Desired Point, When Raising or Lowering
Weights.)
ALFRED COBHAM + East Street Southport (Lancashire) Art Furnisher and
Decorator do hereby declare the nature of this invention to he as follows:-
I affix to the arms of an ordinary winding pulley a segmental clip eccentric to
the circle of the pulley in such a manner as to allow the cord to run between the
clip and the pulley, when the winding cord is pulled it throws the clip off in a
tangent and allows the cord to run free on the pulley, when the hold on the cord
is released it catches the clip, throws it back on to the pulley, and because of its
eccentricity it bends the cord in the groove of the pulley, greater in proportion to
the greater weight or strain it has to sustain, and immediately locks the pulley
and cord from running.
1
T1900
An Improved Self-acting Pulley Lock (for Gripping and Checking the
Run of the Cord at any Desired Point, When Raising or Lowering
Weights.)
I, ALFRED COBHAM of 4 East Street, Southport, Blind Maker, 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 pulley-blocks or winding wheels or rollers, for raising,
lowering and sustaining objects at varying heights, and my invention consists
of a lock or segmental clip, which is carried by the pulley frame or forks, and
which is so mounted in relation to the pulley periphery that when the rope or
cord is being pulled or operated vertically in raising and lowering the weight, it,
the lock, is inoperative, or when the hold on the cord is releaseu, or the cord is
allowed to run back at an angle, it immediately binds the rope in the groove of
the pulley and so locks the pulley, and sustains the load.

page_text: And in order that my said invention may be more readily understood and carried
into practical effect, I have hereunto annexed a sheet of drawings and will now
proceed to describe the same with the assistance of the figures and letters of
reference marked thereon.
Figs. 1 and 2 represent a pulley-block (with two pulleys or sheares) as adapted
for use with a clothes rack and with my invention applied thereto.-Fig. 1 shewing
the pulleys (or rope) free, and Fig. 2 shewing the pulleys (or rope) locked or kept
in check. Fig. 3 shows the lock separately.
Fig. 4 shews the application of my invention to another type of pulley, and
Fig. 5 illustrates its application to a blind roller.
In accordance with my invention T employ a segmental shell-like device or
clip (A) which is formed with curved hack and side cheeks designed to embrace
the peripheries of the two pulleys (B), and to he axled on axes (C) carried in
extensions (D) of the pulley forks (E). The position of the axes (C) in relation to
the axis (F) of the pulleys gives an eccentric throw to the clip (A), or causes its
upper edge to approach and recede from the pulley peripheries.
With a rope travelling over the pulleys in the direction of the arrow (G) (sea
Fig. 2) and the upper edge of the said clip or its teeth or claws (H) caused to
come or press against the rope, the effect, by reason of the clip trying to move over
its centre is like that of an anchor as hetween axes (C) and claws or teeth (H),
and the greater the pull or load in the direction of the arniw (T) the greater the
contact of the teeth (IT) with the rope, and as a consequence the movement of
the rope is arrested, and a resistance is offered sufficient to sustain the weight.
The position of the device or clip (A) and the rope when a load is heing raised
or lowered is as shewn in Fig. 1, the clip heing thrown well hack by reason of
the rope passing hetween the cross pin (T) and the lower transverse edge (K) of the
clip. When it is required to lock the rope, or sustain the weight at a desired
height, the hold on the rope is released, and, hy preference at an angle as shewn
in Fig. 2, when the clip immediately tilts up, and presses its teeth (H) on to the
rope and in the manner aforesaid becomes anchored to the rope and binds it in the
grooves of the pulleys and prevents further movement.
The application of my invention to other forms of pulleys or wheels and to the
pulleys shown in Figs. 4 and 5 differs in no essential particular from that of the
pulley shown in Figs. 1 and 2. In all the applications no separate cord or rope
is used for operating the lock, the rope for raising and lowering the weight being
alone used, which is an advantage more particularly manifest with a window
blind pulley or roller.
Whilst I prefer the teeth or claws (H), I may employ a ridge or rib (L) see
Fig. 4, or I may flute or roughen the interior of the clip, or otherwise adapt or form
it for effectually engaging with the rope. In lieu of engaging with the rope, I
may arrange for the clip to engage with the pulleys, or hoth, but I prefer it to
art on the mpe only.
Having thus particularly described and ascertained the nature of my said.
invention and in what manner the same is to be performed I wish it to be under-
stood that whilst I prefer the improved lock to he of the form shewn and to he
mounted in the manner illustrated, which lends itself to cheapness of production
and compactness of construction it may be of other forms and he variously mounted
without departing from my invention, and what I claim is:-
1. A pulley or like device used for raising or lowering objects, fitted with a
lock or clip mounted eccentrically to its periphery and binding the rope or cord
in the groove of the pulley or pulleys when such rope or cord is let-go or released,
a and for the purposes set forth.
2. The combination of a pulley, wheel or roller (or a set of such devices) with a
shell-like device or clip (A). mounted upon axes (C) in extensions (D) on the
pulley forks (E), and designed to engage with the rope or cord, as set forth and
illustrated on the accompanying drawing.

page_text: 3. The combination of parts shewn in Fig. 4 of the accompanying drawing.
4. The combination of parts shewn in Fig. 5 of the accompanying drawing.
Dated this 21st day of April 1897.
ALFRED COBHAM.
By John G. Wilson & Co., M.I.M.E.,
55 Market Street, Manchester, Agents.