Improvements in Hoisting and Driving Gear, and in Brakes and Sheaves therefor.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in Hoisting and Driving Gear, and in Brakes and
Sheaves therefor.
THOMAS LOCKERBIE, 218, Rhodeswell Road, Limehouse, London, East, Engineer,
and FREDERICK JAMES SALMON, 249, Romford Road, Forest Gate, in the County of
Essex, Mineral Water Manufacturer, do hereby declare the nature of this invention
to be as follows:-
This invention has reference to that class of hoisting gear which is described in
the Specification of the Letters Patent granted to Thomas Lockerbie and dated
Feb. 13th 1894 No. 3120.
One part of the improvements consists in preventing the loose sheeve from revolv-
ing on its spindle after it has been unlocked from the sheeve which is made fast
to said spindle.
This is effected by combining the brake gear and the locking in one mechanical
arrangement.
In the improved combined brake-locking gear the central locking pin with its
feather and projection are retained as described in the above named specification
the improved locking pin being screwed at one end for a nut which forms part
of the centre of a chain sheeve and is used to apply the brake, and to lock and
unlock the two sheeves as required.
When unlocking the two lifting sheeves, a pawl or catch held clear by a spring
is first let drop into a slot in the circumference of the loose sheeve, so as to prevent
the sheeves from revolving either way, and to keep the feather projection on the
locking pin in line with a slot in the frame.
The first motion of the locking sheeve above named applies the brake, and when
the full strain of the brake is applied, further motion in the same direction, draws
or pushes the feather projection from the slot in the sheeve to the slot in the frame,
and the loose sheeve is free to revolve, when the. brake is released. Provision is
made in the mechanism to admit of the brake being released and re-applied without
disturbing the locking gear.
A second part of the improvements consists in using the brake-locking gear
sheeve, as a driving sheeve to impart motion to the lifting sheeves, and in this
arrangement nearly double the height of a lift can be made with a given length
of chain, to what can be done at present by the class of hoisting gear above referred
to.
By using the above described combination sheeve it becomes possible to use a
fine wire line in differential pulley blocks for the lifting part, and chain or rope
for the driving part and in order to provide grip sufficient to prevent the line

page_text: from slipping in the sheeve the inner faces of the sheeve are faced with rubber,
leather or other yielding material, or two air inflated discs may be attached to the
inner faces together with a nearly unyielding resting groove for the lifting line.
These inflated dises may be protected by suitable metal strips arranged in seg-
mental parts on the exposed parts of the surface.
The wire or rope lines may have raised parts at equal distances in the length
of the lines, said raised or swelled parts being so arranged as to fit into the spaces
between the segmental strips on the faces of the sheeves, and provision may also
be made for releasing or relaxing the grip on the line at the proper point.
Dated this 17th day of February 1898.
T. LOCKERBIE.
FREDK. J. SALMON.
Improvements in Hoisting and Driving Gear, and in Brakes and
Sheaves therefor.
We, THOMAS LOCKERBIE, of 101, Hind Street, Poplar, late of 218, Rhodeswell
Road, Limehouse, in the County of London, Engineer, and FREDERICK JAMES
SALMON, of 249, Romford Road, Forest Gate, in the County of Essex, Mineral
Water Manufacturer, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:.
-
This invention has reference to that class of hoisting gear which is described in
the Specification of Letters Patent granted to Thomas Lockerbie and dated
Feb. 13th 1894 and numbered 3120.
One part of the improvements consists in preventing the loose sheave from
revolving on its spindle after it has been unlocked from the sheave which is made
fast to the said spindle.
This is effected by combining the brake gear and the locking gear in one
mechanical arrangement.
In improved combined brake-locking gear the central locking pin with its
feather and projection are retained as described in the above named specification
the improved locking pin being screwed at one end for a nut which forms part of
the centre of a chain sheave, and is used to apply the brake, and to lock &
unlock the two lifting sheaves as required.
When unlocking the two lifting sheaves, a pawl or catch, held clear by a spring
is first let drop into a slot in the circumference of the loose sheave, so as to prevent
the sheaves from revolving either way, and to keep the feather projection on the
locking pin, in line with a slot in the frame.
The first motion of the locking sheave above named, applies the brake, and when
the full strain of the brake is applied, further motion in the same direction draws,
or pushes the feather projection, from the slot in the sheave to the slot in the frame,
the latter operation makes the spindle and one sheave fast to the frame, and the
loose sheave is free to revolve when the brake is released.
Provision is made in the mechanism to admit of the brake being released, and
re-applied without disturbing the locking gear.
A second part of the improvements consists in using the brake-locking sheave
as a driving sheave, to impart motion to the lifting sheaves, and in this arrange-
ment, nearly double the height of a lift can be made with a given length of chain,
to what can be done at present, by the class of hoisting gear above referred to.

page_text: By using the above described combination sheave, it becomes possible to use a
fine wire line in differential pulley blocks for the lifting part and chain or rope
for the driving part, and in order to provide "grip" sufficient to prevent the line
slipping in the sheave, the inner faces of the sheave are faced with leather, rubber
or other yielding material, or two air inflated discs may be attached to the inner
faces together with a nearly unyielding resting groove, for the lifting line.
These inflated discs may be protected by suitable metal strips arranged in seg-
mental parts on the exposed part of the surface.
The wire or rope lines may have raised parts at equal distances in the length of
the lines, said raised or swelled parts being so arranged as to fit into the spaces
between the segmental strips on the faces of the sheaves, and provision may also
be made for releasing or relaxing the grip on the line at the proper point.
To enable our invention to be better understood, we will describe it by reference
to the accompanying drawing in which
Fig. 1 is a sectional elevation of the improved combination gear as applied to
an ordinary pair of chain sheaves, the braking power being obtained by tightening
the two arms of the sheave frame.
Fig. 2 is a part side elevation of the combination sheave.
Fig. 3 is a sectional plan showing a method of applying the brake by drawing
or forcing a disc against the loose sheave.
Fig. 4 is a side elevation of part of the apparatus employed for the above purpose.
Figs. 5 & 6 are two sections of a sheave adapted for a line with raised or
swelled parts at intervals. Figs. 7 & 8 are two sections of a sheave adapted for
ordinary rope or plain wire line.
Figs. 9 & 10 show the above but with releasing mechanism for a sheave made
fast to a revolving spindle.
With reference to Figs. 1 & 2 A and A¹ are two sheaves which form a differential
pulley block, the sheave A is made fast to the hollow spindle B and the sheave A¹
is shown made fast to the spindle B by a projection C₁, on the locking pin C.
A2 is a sheave which is used in turns for locking braking and driving, and as
shown in Fig. 1 the sheave A¹ is locked to the spindle by the projection C on the
pin C.
B is a collar made fast to the hollow spindle B. The outer edge B2 being
enlarged to form a shoulder. The centre of the sheave A2 is screwed to fit the
locking pin and is recessed to fit a thrust cap A³ the two being fastened together
by screwed pins or otherwise.
In the hollow of the cap A³ the collar B' works loosely, the shoulder B³ acting
as a thrust when locking and driving.
C is a moveable collar on the back end of the locking pin D is a forked lever
hinged to the frame E and held clear of a notch A' in the sheave A¹ by a spring El.
The mechanism as shown in Fig. 1 represents a differential pulley block, the
lifting chains or lines being arranged on the sheaves, so that when turning the
driving sheave A² in the direction indicated by the arrow, the weight rises, and
in turning in the opposite direction, the weight is lowered slowly.
When quick lowering is desired the lever D is pulled down and the sheaves
turned round until the projections on the lever drop into the notch A in the
sheave A¹.
By now turning the locking sheave in the direction of the tail of the arrow
Fig. 2, the sheave will travel along the locking pin until the thrust cap A³ comes
in contact with the centre of the frame E, and by further turning in the same
direction the locking pin C will travel outwards, and transfer the projection C¹
from the recess in the sheave to the recess in the frame, at the same time bringing
the collar C in contact with the opposite centre of the frame, and thereby holding
the sheave A¹ sufficiently tight to prevent the weight from lowering.
As soon as the projection C enters the slot in the frame, the lever D may be let
go when the spring E lifts it out of the notch.

page_text: By now easing back the sheave A2, the lowering of the weight can be regulated
to any desired speed, or stopped at any point required. With reference to Figs. 3
and 4 A & A are the two lifting sheaves, A2 the locking sheave, B, the hollow
spindle, C the locking pin, C the projection thereon, and EE the frame, all having
the same functions to perform as described for Fig. 1 & 2.
I is a disc of sheet iron, and may be faced with wood, leather, or other like
material, to prevent slipping. G is a three armed bracket, connecting to the disc
by distance stays, HH which works through suitable guide holes in one side of
the frame.
The boss of the driving sheave A² is screwed and fitted with a centre thimble A³
the outer end A being enlarged to form a shoulder, and the centre screwed to fit
the locking pin C.
The centre of the bracket G is recessed to fit on to the enlarged end of the
thimble A3 as shown in Fig. 3, the two sheaves, A and A¹ are locked together, the
thimble A3 being forced against the end of the spindle B, and the projection Con
the pin C, being fast in the recess in the boss of the sheave A', the alignment of the
projection and recess being accomplished as described with reference to Fig. 1.
To apply the brake and unlock the sheaves A and A¹, the sheave A2 is turned.in
the opposite direction to that described for locking; the first few turns bringing
the shoulder of the thimble A³ in contact with the bottom of the recess in the
bracket G, also bringing the disc F in contact with the outer edge of the sheave A¹,
and drawing. it close to the fast sheave A, thereby keeping the weight suspended
untill the brake is released, as described with reference to Fig. 1.
With reference to Figs. 5 & 6 A, A are two metal discs, and form the two sides
of a sheave, B is the spindle on which said sheave is mounted I is a grooved ring,
inserted between the two discs A, A. K is a rubber or leather lining into which
the raised or swelled parts of the line grip, L is a thin metal clip fitting into the
groove, the top ends being held fast between the discs, A, A, and the metal ring I,
the bottom being held fast by one or more metal projections which pass through
the lining K and the metal ring I, or the bottom may be secured by a screwed
pin passing through the metal ring I into a raised part of the clip L
These clips keep the groove in proper shape, and prevent the lining from creeping.
With reference to Figs. 7 & 8 A, A, are two metal discs, which when joined
together by the studs B form the run of a sheave. Hinged on the enlarged part B¹
of the studs are a series of pawls C, which travel inwards in the bottom groove D
of the sheave.
When the rope or line bears on one of these pawls it gives way to the pressure
caused thereby, and the line gets wedged in the groove suffiently to prevent
slipping.
Mounted on the spindle upon which the sheaves revolves, is an eccentric E, upon
which the inner edge of the pawl strikes as the sheave revolves, thereby causing
the loose pawl to moove outwards at the proper point where the rope or line is
required to leave the groove of the sheave.
The eccentric E is so arranged on the spindle, that when a reverse motion takes
place, its position is altered to that shown in dotted lines E¹.
With reference to Figs. 9 and 10 the eccentric on the spindle is replaced by a
roller 2, attached to the frame in which the sheave and spindle revolve, or where
practicable a race may be used. In the larger sized sheaves, a loose connecting
piece E³ is used to transmit the force from the eccentric roller, or race to the pawl,
or a hinged connecting rod, or any other well known mechanical device may be
used.
Having now particularly described and ascertained the nature of our
invention, and in what manner the same is to be performed, we declare that what
we claim is :-
CLAIM.
1
16

page_text: the same motion by which the brake is applied, substantially as described and
illustrated with reference to Figs. 1, 2, 3, and 4.
2. The methods of gripping and releasing a rope or wire line as described and
illustrated with reference to Figs. 5, 6, 7, 8, 9 and 10 said line or rope to be used
for either lifting or driving purposes.
171 .
1000