IMPROVEMENTS IN HOISTS AND OTHER LIFTING AND WINDING MACHINERY
Year: 1884

page_text: PROVISIONAL SPECIFICATION.
I GEORGE CROYDON MARKS of No
Richmond Road Handsworth in the
County of Stafford Mechanical Draughtsman do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN HOISTS AND OTHER LIFTING AND
WINDING MACHINERY" to be as follows:-
My invention consists in constructing and arranging in the manner hereinafter
described the parts of hoists and other lifting and winding machinery whereby
complete control over the pawl and brake of the machine is obtained by operating
upon one lever or system of levers instead of operating on two levers as is usual.
By operating on one lever or system of levers by the pulling of a cord the pawl is
first raised from the teeth of the ratchet wheel and the suspended body thereby
allowed to descend and by further pulling of the same cord the brake is put into
action and the motion of the descending body regulated and controlled.
I will describe my invention in connection with a hoist.
The pawl is jointed to the operating lover at a short distance from its fulcrum so
that when the free end of the lever is depressed by a cord attached to it the pawl
is raised from the teeth of the ratchet wheel. The moveable end of the strap of
the brake is also attached to the said lever and the further depression of the said
lever tightens the strap on the brake. The attendant has thus completo control
over the descent of the suspended body by the pulling more or less of a single cord
attached to the lever described.
For heavy and other special work I employ a cranked lever to the short arm of
which the pawl is jointed. When a very heavy body is suspended by the hoist the
thrust from the teeth of the ratchet wheel acting through the pawl causes a tooth
or projection on the back of the pawl to press upon the lever and by depressing it
to tighten the strap of the brake. The brake is thus made automatic.
The application of my invention to lifting and winding machinery other than
hoists differs in no essential respects from its application to hoists as herein before
explained.

page_text: COMPLETE SPECIFICATION.
I GEORGE CROYDON MARKS of N° 8 Richmond Road, Handsworth in the
County of Stafford, Mechanical Draughtsman do hereby declare the nature of
my Invention for "IMPROVEMENTS IN HOISTS AND OTHER LIFTING AND WINDING
MACHINERY and in what manner the same is to be performed to be particularly
-deseribed-and-ascertained in and by the following statement :—
"
E
My invention consists in constructing and arranging-in-the-manner_herein_after_
described the parts of hoists and other lifting and winding machinery, whereby
complete control over the pawl and brake of the machine is obtained by operating
upon one lever or system of levers instead of operating on two levers as is usual.
By operating on one lever or system of levers by the pulling of a cord, the pawl is 1
first raised from the teeth of the ratchet wheel and the suspended-body-thereby
allowed to descend and by further pulling of the same cord the brake is put into
nction and the motion of the descending body regulated and controlled.
I will describe my invention-in-connection-with.a hoist..
The pawl is jointed to the operating lever at a short distance from its fulcrum so
that when the free end of the lever is depressed by a cord attached to it the pawl
is raised from the teeth of the ratchet wheel. The moveable end of the strap of the
brake is also attached to the said lever and the further depression of the said lever
tightens the strap on the brake. The attendant has thus complete control over the
descent of the suspended body by the pulling more or less of a single cord attached
to the lever described.
For heavy and other special work I employ a cranked lever to the short arm of
which the pawl is jointed. When a very heavy body is suspended by the hoist the
thrust from the teeth of the ratchet wheel acting through the pawl causes a tooth
or projection on the back of the pawl to press upon the lever and by depressing it 2
to tighten the strap of the brake. The brake is thus made automatic.
The application of my invention to lifting and winding machinery other than
hoists differs in no essential respects from its application to hoists as herein before
explained.
Figure 1 of the accompanying Drawing represents in side elevation and Figure 23
in plan, a portion of a hoist to which my improvements are applied; Figures 3
and 4 represent respectively in side elevation and plan, the ratchet and brake parts
of the hoist detached. The same letters of reference indicate the same parts in
Figures 1, 2,
and 4.
a is the hand rope wheel keyed on the shaft and b is the lifting rope wheel 3
keyed on the parallel shaft, the said shafts land k being geared together by the
pinion c and toothed wheel d. The said shaft k also carries the ratchet wheel e and
broke wheel f; gg is the pawl lever pivoted upon the pin or centre h the pawl end
of. the said lever engaging with and preventing the rotation of the ratchet wheel e
in one direction. The said pawl lever is balanced by the weighted arm g³ so as to 4
bring its pawl end into the teeth of the ratchet wheel e. The pin or centre h of

page_text: the pawl lever is carried by a portion of the brake strap n. The pin or centre h
not only passes through the said lever but also passes through the eye of the forked
connection m of the brake strap n. Into the opening between the branches of the
forked connection m a cranked lever j is passod and jointed by the pin h. The said
pin thus serves as the joint pin of the lover as well as that of the pawl
lever g, both the said levers being connected to the brake strap connection mas
seen in Figures 2 and 4. The other end of the brake strap n has attached to it the
forked connection p between the branches of which the lever j is passed, the said
lever being jointed to it by the pin i. The pin i is passed through the said lever į
and through the eye of the brake strap connection p and is also passed through and
fixed to the frame o of the hoist (sco Figure 2). Upon the fixed pin i, the lover j
is free to turn carrying with it, in its motion, the pawl lever g g³ and brake
connection m.
The action of the parts of the hoist is as follows:-On turning the hand rope
wheel a in the direction proper for lifting the load or weight suspended upon the
rope or chain of the lifting wheel b, the ratchet wheel e on the same shaft is also
rotated the teeth of the said ratchet wheel slipping under and lifting the pawl end
of the pawl lever g which lever g is thus made to turn upon the centro or pink, the
balance weight on the end of the arm g³ of the pawl lever keeping it engaged with
the teeth of the ratchet wheel. On liberating the rope of the rope wheel a so as to
arrest the lifting motion of the load, the ratchet wheel e being now acted upon by
the suspended load, causes the ratchet wheel e to rotate in the contrary direction to
that in which it moves when raising the load, thereby pressing the teeth of the
ratchet wheel upon the pawl lever g and causing the said lever g through the crank
lever to turn upon the fixed centre or pin i. As the pawl lever g turns upon the
pin the brake strap connection m moves with it, thus tightening the brake
strap upon the brake wheel f. The load is thus automatically sustained or
suspended in the position to which it has been lifted.
In order to lower the suspended body it is necessary to depress the handle end of
the pawl lever g by a cord attached to it until the pawl end is lifted and disengaged
from the ratchet wheel e, the pawl lever turning upon the centre h. Tho load will
now cause the wheel b to rotate rapidly and the load will descend by its own
weight. The motion of the descending load may be arrested or controlled by
further depressing the handle end of the pawl lever g. This movement of the pawl
lever causes it to come into contact with the outer arm of the cranked lever; and
causes the said lever j to turn upon the centre i which centre now also acts as the
centre of the pawl lever g. The two levers g, j being thus made to turn bodily
upon the centre i causes the brake strap n to bo tightened upon the brake wheel f
and arrest or regulate the motion of the hoist. On liberating the handle end of the
lever the belt strap is relaxed and the pawl of the said lever g falls into the teeth
of the ratchet wheel c by the action of the weighted arm g² and the load is held in
its suspended position by the operation of the pawl and ratchet wheel as before
I
described.
Figure 5 represents in side elevation and Figure 6 in plan an arrangement of my
invention which I prefer to adopt when light loads are to be lifted.
In this arrangement the pawl lever.g, g turns upon the pin i which passes
through the eye of the brake strap connection p and also through the arm or linkį
into the side or frame of the machine in which it is rigidly secured. The free end
of the brake strap is secured by its connection m to the upper end of the arm or
link by a pin which passes through an elongated holet (see Figure 5) in the
lever g and also through the eye of the brake strap connection m and the arm or
link j. When the pawl end of the lever g g of this arrangement is lifted by the
ratchet wheel the said lever turns upon the pin i but the motion of the said lover
is not sufficient to cause the elongated hole t in the said lever to come in contact
with the pin / hence the arm or link j is unoperated upon and the brake strap is
not brought into action. When however the handle end g of the lever is depressed
to a greater distance under the circumstances herein before pointed out, the pin h

page_text: is acted upon by the pawl lever g and the brake strap is now brought into action
and the motion of the load or weight is arrested and suspended.
Figure 7 represents in side elevation and Figure 8 in plan, a crab or winch to
which my improvements are applied. In order to adapt my improvements to
a crab or winch they are modified in the following manner. I use a lever g, g³
turning upon a pin r on the framing of the crab or winch and the short arm of the
said lever bears upon a ratchet pawl q, q' which turns upon the pin 8. The eye of
the connection p of the brake strap is secured to the pin r on the fixed framing and
the eye of the other connection m of the brake strap is connected to the arm g
of the lover g, 92. On raising the handle end g of the lever the short arm g³ is
'depressed and acting upon the short arm g of the ratchet paw! q, q raises the said
ratchet pawl from the ratchet wheel c. The further movement of the handle end g
of the lever g, g' in the same direction tightens the brake strap upon the brake
wheel and the load is thus sustained as herein before described.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
Connecting the pawl lever or the lever operating upon the pawl of the ratchet
wheel of hoists and other lifting and hoisting machinery to the brake strap of the
_aid_hoists_and_other lifting and hoisting machinery-substantially-in-the-several
ways herein before described and illustrated in the accompanying-Drawing,
whereby the said lever when operated upon either by hand or automatically
by the machine, first disengages the pawl from the ratchet wheel and afterwards
by the further movement of the lever in the same direction puts into action the
-brake-strap_for_regulating and controlling the motion of the weight or load
substantially as described and illustrated.