IMPROVEMENTS IN WINCHES
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by the said Walter Pitt at the Office of
the Commissioners of Patents on the 18th December 1882.
WALTER PITT of Bath in the County of Somerset.
AND OTHER LIFTING APPLIANCES
و"
"IMPROVEMENTS IN WINCHES
The object of my Invention is the construction of a hand winch or hoist which
will afford greater safety and facility in working than the ordinary crab.
For this purpose I connect the axis which receives the winch handle or hand rope
wheel with the winding drum through the medium of a train of gear wheels and I
mount a portion of the train upon a support which may either be allowed to move
around the axis or be held fast by a brake. When the support is held fast by the
brake it serves as a fulcrum through which the power is transmitted from the handle
to the drum but when the fulcrum is permitted to yield the drum is free either to
remain at rest or to turn independently of the handle under the influence of a
load suspended from it, backward motion of the handle being prevented by means
of a ratchet.
As I prefer to arrange it the axis which receives the handle is carried in bearings
upon two standards and between the standards the drum is mounted loosely on the
axis. A disc is fixed upon one end of the drum and a stud axis on the face of the
disc carries a pinion which engages with another pinion fast upon the axis. The
pinion on the disc also engages with a ring of internal teeth within a brake drum
which also would free to turn on the same axis were it not embraced by a brake
strap attached at one end to the frame and at the other to a loaded tightening
lever. The axis has also a ratchet fast upon it and with this pawl is always in
gear so that under no circumstances can the handle turn backwards.
It will be seen that so long as the brake drum is held fast and the axis turned
by the handle the pinion on the axis rotates the pinion carried upon the disc. This
latter pinion then climbs around the stationary teeth on the brake drum carrying

page_text: with it the disc and the winding drum to which the disc is attached. But when
the brake yields, (as it will do if an undue strain be applied in an attempt to lift
too heavy a load) the winding drum remains at rest and the only effect of moving
the handle is to rotate the brake drum. When the brake is relieved by lifting the
brake lever the load suspended from the drum descends causing the rotation both
of the winding drum and of the brake drum. The lowering of the load is thus
effected without having to disconnect any of the gearing.
The load will remain automatically suspended at any point as the pinion
connected with the barrel is prevented from revolving by the combined action of
the brake and the ratchet.
Instead of a strap brake any other convenient form of brake may be used and
the weight which acts on the brake may be replaced by a spring.
'
If it is required to lift a considerable load, a train of wheel gearing may be used
and the safety mechanism may be interpolated at any position between the handle
and the barrel.
The invention is also applicable to lifts hoists, or other lifting appliance worked
by hand either by winch handles or rope wheels.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Walter Pitt in the Great Seal Patent Office on the 18th June
. 1883.
"
WALTER PITT of Bath in the County of Somerset 'IMPROVEMENTS IN WINCHES
AND OTHER LIFTING APPLIANCES"
The object of my Invention is the construction of a band winch or hoist which
will afford greater safety and facility in working than the ordinary crab.
For this purpose I connect the axis which receives the winch handle or hand rope
wheel with the winding barrel through the medium of a train of gear wheels and I
mount a portion of this train upon a support which may either be allowed to move
around an axis or be held fast by a brake. When the support is held fast by the
brake it serves as a fulcrum through which the power is transmitted from the handle
to the winding barrel but when the fulcrum is permitted to yield the winding barrel
is free either to remain at rest or to turn independently of the handle under the
influence of a load suspended from it, backward motion of the handle being prevented
by means of a ratchet.
As I prefer to arrange it the axis which receives the handle is carried in bearings
upon two standards and between the standards the winding barrel is mounted loosely
on another axis. A disc is fixed upon one end of the barrel and a stud axis on the
face of the disc carries a pinion which engages with another pinion fast upon the
axis of the winding barrel. The pinion on the disc also engages with a ring of
internal toeth within a brake drum which also would be free to turn on the same
axis were it not embraced by a brake strap attached at one end to the frame and at
the other to a loaded tightening lever. The handle axis has also a ratchet fast upon
it and with this a pawl is always in gear so that under no circumstances can the
handle turn backwards.
It will be seen that so long as the brake drum is held fast and the axis of the
winding barrel turned by the handle the pinion on the axis rotates the pinion
carried upon the disc. This latter pinion then climbs around the stationary teeth
on the brake drum carrying with it the disc and the winding barrel to which the
disc is attached. But when the brake yields, (as it will do if an undue strain be
applied in an attempt to lift too heavy a load) the winding barrel remains at rest
and the only effect of moving the handle is to rotate the brake drum. When the
brake is relieved by lifting the brake lever the load suspended from the winding
barrel descends causing the rotation both of the winding barrel and of the brake
drum. The lowering of the load is thus effected without having to disconnect any
of the gearing. The load will remain automatically suspended at any point as
the pinion connected with the barrel is prevented from revolving by the combined
action of the brake and the ratchet.
Figure 1 is a side elevation partly in section and Figure 2 is an end elevation of
a winch constructed according to my Invention.
a a are the standards.
b an axis which receives the crank handle c.
d is the winding barrel. e is its axis, on which it is free to turn.
61 and e, are a pinion and wheel gearing the axes b and e together. f and ƒ' are
ratchet and pawl preventing the handle turning back. g is a brake drum provided
with internal teeth at g' and it is so mounted that it can turn upon the axis e.
h is a brake strap embracing the brake drum g-it is attached to the shorter arm of
the lever i, the weight on the longer arm of the lever tightens the strap upon
the brake drum.

page_text: e is a pinion fast on the axis e and k is another pinion in gear with e² and also
with the teeth g'. The pinion k is carried upon a stud fixed into a disc forming
one end of the winding barrel d.
Instead of a strap brake any other convenient form of brake may be used and
the weight which acts on the brake may be replaced by a spring.
If it is required to lift a considerable load, a train of wheel gearing may be used
and the safety mechanism may be interpolated at any position between the handles
and the barrel.
The Invention is also applicable to lifts, hoists, or other lifting appliances worked
by hand either by winch handles or rope wheels.
Having thus described the nature of my said Invention and the manner of
performing the same I would have it understood that I claim as my improvements
in winches and other lifting appliances.
First. Mounting upon a moveable support a portion of the gear through which.
the handle or hand mechanism actuates the winding barrel, and retaining such
moveable support by a brake to permit of its acting as a fulcrum substantially as
described.
Second. The improved winch or lifting apparatus substantially as described.
In witness whereof I the said Walter Pitt have hereunto set my hand and seal
this twelfth day of June in the year of our Lord One thousand eight
hundred and eighty three.