Improvements in Lifts and Hoists.
Year: 1888

page_text: Date of Application, 3rd Dec., 1888
Complete Specification Left, 3rd Sept., 1889-Accepted, 5th Oct., 1889
Improvements in Lifts and Hoists.
We, HENRY CLAUDE WALKER and ROBERT CAREY both of the Newington Iron
Works, Falmouth Road, London S.E. Engineers do hereby declare the nature of this
invention to be as follows:-
Our invention relates to improvements in the controlling apparatus and safety gear
of lifts and hoists and has for its object certain improvements in :-
1. The controlling valve and means for operating the same.
2. The safety gear for stopping and holding the cage should the lifting rope
break.
3. Additional safety gear for stopping the cage by band from the inside of cage
or by means of a centrifugal governor which comes into action when the normal speed
is exceeded.
1. Lifts as ordinarily constructed are controlled by a hand rope which extends up
the full height of the lift "well" and passes through or near the cage. This rope
passes over a sheave or sheaves at the top of "woll" and is carried down a suitable
distance. The weighted lever for operating the controlling valve is connected to
one end of this rope the other end having a counterweight to balance the weighted
lever. The lever is connected to the valve in such a manner that when it is depressed
water is admitted into the lift cylinder and when raised the cylinder exhausts or vice
versa according to the position of the cylinder port relatively to the exhaust. The
effect of this arrangement is that should the hand rope break at any time the weighted
lever is deprived of its counterpoise and falls to its lowest position thereby causing
the cage to nove in the direction corresponding to the position of the lever. In
passenger lifts this movement naturally gives alarm to the passengers especially when
the cage happens to be moving in the contrary direction when the rope breaks.
To obviate this we arrange the controlling gear of our invention so that should the
hand rope break the cage inmediately comes to a standstill. This is accomplished by
giving the lever a little longer stroke than is necessary to work the cage up and down
and we arrange the valve and levers in such a manner that when the weighted lever
is in its lowest position both the exhaust pipe and the pressure water are shut off
from the cylinder. This extra movement may be allowed for on the valve when a slide
valve is used or on the levers.
When a slide valve is used we preferably allow the slide a little longer travel on
the one side corresponding to the extra travel of the lever. If the arrangement of
valve and levers is such that when the lever is depressed to the ordinary extent the
cylinder exhausts from the cylinder port to the exhaust port through the chambered
portion of slide, we provide the slide with sufficient lap on the exhaust side to com-
pletely cover the exhaust port when the lever reaches its extreme lowest position. On
the other hand if the arrangement is such that when the lever is depressed to the
ordinary extent the cylinder port receives pressure water from the valve casing, we
extend the slide face on the pressure side and allow the pressure water to pass through
a slot or opening instead of past the end of slide as customary and we make the
extended portion of valve face past the slot aforementioned sufficiently wide to com-
pletely cover the cylinder port when the lever reaches its extreme lowest position.
When it is inconvenient or impossible to allow for this extra movement on the
valve itself-we allow for it on the levers in the following manner :-We use two
weighted levers instead of one. The first lever is connected at one end to the hand
rope by which it is operated and at the other to the valve by means of suitable links

page_text: -
and is fulcrummed between these two points on the second lever. This second lever
has a fixed fulcrum at one end and at the weighted end a stop or lug which ordinarily
rests on the first lever by the influence of its weighted end. A fixed stop is provided
on which the second lever rests when in its ordinary lowest position.
The effect of this arrangement is that during the ordinary travel of hand rope the
two levers act virtually as a single lever of the second order, but should the rope
break the second lever descends to the fixed stop but no further whilst the first lever
descends alone to its extreme position and by becoming a lever of the first order brings
the valve to its central position.
In some cases instead of the usual arrangement of hand rope as aforementioned
we attach one end of the rope to the weighted end of the levor which controls the
valve and carry the rope up the lift "well" and round two or more sheaves connected
with the cage and attach it to any convenient fixed support at the top of lift "well."
One or all of these sheaves is or are mounted on a rocking or sliding mechanism
provided with a lever or hand wheel and arranged in such a manner that by their
means the weighted valve lever aforementioned can be elevated or depressed at will
without being affected by the travel of cage up and down the lift" well."
2. This part of our invention relates to lifts and hoists having safety gear so
arranged that the lifting rope breaking will put this gear into action. In cages-with
four lifting ropes constructed with this gear in the ordinary manner these ropes are
each attached to a serrated cam held out of action by the pull of the ropes and put
into action on the breaking of the rope by a spring which causes them to press
against the "runners" and so stop the cage. This arrangement has the objection that
when one rope breaks the cam to which it is attached goes into action suddenly and being
situated at one side of the cage it's action strains the framework of cage considerably
and may also cause accidents to the passengers through the breaking of the glass
windows.
To obviate this we construct the safety gear of our invention in the following
manner We retain the four serrated cams but secure them on two shafts passing
under the floor of cage and coupled together so that they all go into action simul-
taneously. These cams are in their normal condition kept out of action by a spring
or weighted parts. The ends of the lifting ropes are each provided with a suitable
adjusting screw for taking up any slack caused by stretching and pull against a
spring which bears against some part of the frame of cage. Connected with each
adjusting screw is a rod passing down through an eye or guide secured to the frame
and bearing against a lever forming part of or connected to the corresponding cam
but the cains are free to move without the rod. The effect of this arrangement is
that under ordinary conditions the cage wholly or partially rides on the springs but
should any of the ropes break, the spring against which it normally pulls is relieved
of it's load and by means of the rod aforementioned presses it's cam into action and
as the cams are all coupled up the strain caused by the stoppage is evenly distributed
throughout the framework of cage.
In some cases we attach additional appliances for putting these cams into action
such as for instance a light frame a little distance below the floor of cage which
would come into action if anything got in the way of the cage during its descent,
or we may apply one end of a rope or chain to the cams or cam levers in a con-
venient manner and the other end to multiplying sheaves or a barrel connected to the
motive power in such a manner that this rope is paid out or hauled in exactly at the
same speed as the lifting rope or ropes and for the purpose of putting the cams into
action should the lifting rope or ropes all break near their connection to the cylinder
or motive power as in this case sufficient friction might be caused by the sheaves or
barrel over which it or they run to prevent the springs on cage putting the cams into
action. The extra rope might be fixed to the balance weight where one is used to
come into action if it's rope broke.
3. The third part of our Invention relates to auxiliary safety apparatus whereby the
cage may be gradually brought to rest independently of the main safety apparatus' as

page_text: described in the second part of our invention and also independently of the controlling
rope or lever.
In carrying out this part of our Invention we do not use serrated cams but use
cams with a smooth surface or blocks which may be wedged up against the
"runners." These cams or-blocks are put into action by a toothed or fluted wheel
driven by being pressed against one of the " runners and by means of a suitable
mechanism pressing the cams or blocks against the " runners with increasing
pressure until sufficient friction has been set up to stop the cage.
"
"
In one form of this part of our Invention this wheel is mounted in such a manner
that any resistance to its revolution only tends to press it more firmly against the
runner "when the cage is descending. It is put into action by a lever having a
weight or spring ordinarily kept out of action by being held by a trigger. This
trigger may be released from the interior of the cage by attaching a suitable cord or
rod thereto or it may be released by a centrifugal governor attached either to the
cage or to some part of the lift "well," preferably at the top of the framing. When
this governor is attached to the cage it is driven either by a special rope or ropes
suitably secured at the top and bottom of the lift "well" or by means of the con-
trolling valve rope and is so arranged that when it's revolutions exceed a certain
speed and the centrifugal force takes effect it by means of a cord or other attachment
releases the trigger aforementioned and allows the cams or blocks to come into action.
When this governor is attached to the framing at the top of hoist or lift "well" it is
driven by a rope one end of which is attached to the trigger aforementioned on the
cage and the other end to a counterweight to keep the rope taut. The trigger in this
case is provided with sufficient resistance to prevent it's withdrawal by the pull on
the rope caused by the friction of governor spindle and attachments when the cage is
descending. When the governor comes into action it arrests the rope by means of
a suitable brake or like arrangement and so releases the trigger.
In another form of this part of our Invention we mount the governor on the cage
and drive it by means of a toothed or fluted wheel kept constantly in contact with
one of the "runners" by a spring or other suitable means. The spindle on which
this wheel is mounted is provided with a clutch put into action by the said governor
and by means of which the motion of the spindle puts the cams or blocks into action
by suitable gear. This clutch may also be provided with a lever or other convenient
mechanism for putting it into action from the interior of the cage independently of the
governor.
The effect of this third part of our Invention is that the cage may be stopped at
will from the interior of the cage independently of all other means and will be
brought to a standstill gently and gradually either by this said means or by the
governor which will effectually prevent undue speed of descent which would be caused
for instance by the breaking of the cylinder or connections in which case there might
remain sufficient pull on the lifting ropes to prevent the ordinary safety gear coming
into action.
Dated this 2nd day of Danamber 1888
HENRY CLAUDE WALKER.
ROBT. CAREY.
COMPLETE SPECIFICATION.
Improvements in Lifts and Hoists.
We, HENRY CLAUDE WALKER and ROBERT CAREY both of the Newington Iron
Works, Falmouth road, London S.E. Engineers 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 :—
Our invention relates to improvements in the controlling apparatus and safety gear
of lifts and hoists and has for its object certain improvements in :-
1. The controlling valve and means for operating the same.
2. The safety gear for stopping and holding the cage should the lifting rope break.

page_text: 3. Additional safety gear for stopping the cage by hand from the inside of cage
or by means of a centrifugal governor which comes into action when the cage exceeds
the normal speed.
Lifts as ordinarily constructed are controlled by a hand rope which extends up the
full height of the lift "well" and passing through or near the cage. This rope
passes over a sheave or sheaves at the top of "well" and is carried down a suitable
distance. The weighted lever for operating the controlling valve is connected to one
end of this rope the other end having a counterweight to balance the weighted lever.
The lever is connected to the valve in such a manner that when it is depressed
water is admitted into the lift cylinder and when raised the cylinder exhausts or
vice versa according to the position of the cylinder port relatively to the exhaust.
The effect of this arrangement is that should the hand rope break at any time the
weighted lever is deprived of its counterpoise and falls to its lowest position thereby
causing the cage to move in the direction corresponding to the position of the lever.
In passenger lifts this movement naturally gives alarm to the passengers especially if
the cage is moving in the contrary direction when the rope breaks.
To obviate this we arrange the controlling valve of our invention so that should
the hand rope break the cage immediately comes to a standstill. This is accomplished
by giving the lever a little longer stroke than is necessary to work the cage up and
down and we arrange the valve and levers in such a manner that when the weighted
lever is in its lowest position both the exhaust port and the pressure water are shut
off from the cylinder. This extra movement may be allowed for on the valve when
a slide valve is used or on the levers.
Where a slide valve is used we preferably allow the slide a little longer travel on
the one side corresponding to the extra travel of the lever. If the arrangement of
valve and levers is such that when the lever is depressed to the ordinary extent the
cylinder exhausts from the cylinder port to the exhaust port through the chambered
portion of slide, we provide the slide with sufficient lap on the exhaust side to com-
pletely cover the exhaust port when the lever reaches its extreme lowest position.
On the other hand, if the arrangement is such that when the lever is depressed
to the ordinary extent the cylinder port receives pressure water from the valve
casing, we extend the slido face on the pressure side and allow the pressure water to
pass through a slot or opening instead of past the end of slide as customary and
wo make the extended portion of valve face past the slot aforementioned sufficiently
wide to completely cover the cylinder port when the lever reaches its extreme lowest
position.
When it is inconvenient or impossible to allow for this extra movement on the valve
itself we allow for it on the levers in the following manner. We use two weighted
levers instead of one. The first lever is connected at one end to the hand rope by
which it is operated and at the other to the valve by means of suitable links and is
fulcrummed between these two points on the second lever. This second lever has a
fixed fulcrum at one end and at the weighted end a stop or lug which ordinarily rests
on the first lever by the influence of this weighted end. A fixed stop is provided
on which the second lever rests when in its ordinary lowest position. The effect of
this arrangement is that during the ordinary travel of hand rope the two levers act
virtually as a single lever of the second order, but should the rope break the second
lever descends to the fixed stop but no further whilst the first lever descends alone to
its extreme position and by becoming a lever of the first order brings the valve to
its central position.
In some cases instead of the usual arrangement of hand rope as aforementioned
we attach one end of the rope to the weighted end of the lever which controls the
valve and carry the rope up the lift "well" and round two or more sheaves con-
nected with the cage and attach it to any convenient fixed support at the top of lift
"well." One or all of these sheaves is or are mounted on a rocking or sliding
mechanism provided with a lever or hand wheel and arranged in such a manner
that by their means the weighted valve lever aforementioned can be olevated or
$

page_text: depressed at will without being affected by the travel of cage up and down the lit
"well."
Figs. 1, 2, 3, 4 and 5 of the accompanying drawings show this part of our
invention.
Fig. 1 shows a lifting and lowering valve. The casing A is of ordinary construc-
tion with inlet a and outlet a'. The lever B is shown in its ordinary lowest position
admitting pressure from casing A to cylinder port C for raising the lift. When lever B
is in the position shown by centre line B' the cylinder port C is covered by the
lap d of valve and the lift is therefore at rest. When lever B is in the position shown
by centre line B' the cylinder port C is put into communication with exhaust port a'
and the lift therefore falls, the positions B, B2 representing the extreme ranges of lever
under ordinary conditions. If the valve rope should break the lever will fall further
to position B and depress the valve so that the extended portion of valve d' will
cover the cylinder port and the lift be brought to rest. The valve D and spindle d²
is of ordinary construction with the exception of extending lap d' on pressure side
with opening d³ for the purposes set forth.
This valve is suitable only when the valve rope is depressed to lift the load this
being the usual requirement when the rope passes through lift cage downwards direct
to the lever, but in some cases a counterweighted rope is carried upwards through
cage then over sheaves at the top and led away to lever. In this case the lever is
generally depressed to lower the cage and the valve arranged as follows
Fig. 2 shows an arrangement of lifting and lowering valve shown with the spindle d
depressed for lowering the load. In this case the extra downward motion of lever
will cause the extra lap d' on valve to cover the exhaust port a¹.
In Figs. 1 and 2 we have shown special valves in which the operating lever is provided
with extra travel downwards to bring the novel portions of valve into action and
stop the cage but in some cases we may use ordinary valves and cause this extra
travel of levers to bring the valve to a central position as follows,
Fig. 3 is a plan and Fig. 4 an elevation of an arrangement of weighted levers for
breaks.
stopping lift if valve rope
The valve rope is attached at one end e of lever E, the other end e¹ being
connected to valve spindle e². This levor E is fulcrummed at e to a second lever F
pivotted at one end to a fixed fulcrum and provided at the other end with weights G
on a rod g. The effect of these weights is to keep this end of lever down and to
cause a stop on it to rest on lever E so that the two levers shall act virtually as
one during the ordinary range of valve rope which is therefore weighted at the other
end to counterbalance both these weights. If the valve rope breaks the levers will
descend together and depress valve spindle until the weight rests ou stop H.
The lever is now prevented from descending furthor so that the further descent of
lever E will raise the valve spindle e' to its central position and will then rest on stop h
in this case fixed to weight rod g.
This arrangement is shown applied to a slide valve but it might be applied either
as shown or modified for spindle or other valves.
I
Fig. 5 shows an arrangement for operating the valve rope 1 by means of a lever J.
inside the cage.
The rope
I is fixed at one end overhead at i and passes under a loose running
'sheave and over sheave passing downwards to valve lever 3. The sheave is
mounted on one end of a counterweighted rocking lever j pivotted to a weight
bar j, to which is fixed the lever J by means of which the efficient length of rope
between top and bottom may he varied to work the valve lever *.
2. This part of our invention relates to lifts and hoists having safety gear so
arranged that the lifting rope will put this gear into action. In cages with four
lifting ropes constructed with this gear in the ordinary manner these ropes are each
attached to a serrated cam held out of action by the pull of the ropes and put into
action on the breaking of the rope by a spring which causes them to press against the
runners and so stop the cage. This arrangement has the objection that when one

page_text: rope breaks the cam to which it is attached goes into action suddenly and being
situated at one side of the cage its action strains the framework of cage considerably
and may also cause accidents to the passengers through the breaking of the glass
windows.
To obviate this we construct the safety gear of our invention in the following
manner-We retain the four serrated camus but secure them on two shafts passing
under the floor of the cage and coupled together so that they all go into action
simultaneously. These cams are in their normal condition kept out of action by a
spring or weighted parts. The ends of the lifting ropes are each provided with a
suitable adjusting screw for taking up any slack caused by stretching and pull against
the spring which bears against some part of the frame of cage. Connected with each
adjusting screw is a rod passing downwards through an eye or guide secured to the
frame and bearing against a lever forming part of or connected to the corresponding
cam but the cams are free to move without the rod. The effect of this arrangement
is that under ordinary conditions the cage wholly or partially rides on the springs
but should any of the ropes break, the spring against which it normally pulls is
relieved of its load and by means of the rod aforementioned presses its cain into
action and as the cams are all coupled up the strain caused by the stoppage is equally
distributed throughout the frame work of the cage.
In some cases we attach additional appliances for putting these cams into action
such as for instance a light frame a little distance below the floor of the cage which
would come into action if anything got in the way of the cage during its descent, or
we may apply one end of a rope or chain to the cam or levers in a convenient
manner and the other end to multiplying sheaves or barrel connected with the
motive power in such a manner that this rope is paid out or hauled in exactly at the
same speed as the lifting rope or ropes and for the purpose of putting the cams into
action should the lifting rope or ropes all break near their connection to the cylinder
or motive power as in this case sufficient friction might be caused by the sheaves or
barrel over which it or they run to provent the springs on cage putting the cams
into action. This extra rope might be fixed to the balance weight where one is used
to come into action if its rope broke.
Fig. 6 is a plan view, Fig. 7 a side elevation and Fig. 8 an end elevation of safety
gear arranged under the cage of lift. These views also show part of the additional
safety gear which will be described hereafter under division 3.
The four lifting ropes have adjusting screws and are each suitably connected to
rods K. These rods are guided by studs & connected to frame. The weight is
carried by springs & bearing against the upper part of stirrups & which pass under
studs aforementioned. The rods K pass through studs and stirrups and have
a rounded head which bears against cam arıns. The four cams L have arms 12 and
are serrated to get a good grip against runners and are mounted on two weigh-
bars extending from side to side and connected together by toothed sectors of
sufficient weight to keep the cams normally out of action.
When one of the lifting ropes breaks its spring presses the corresponding
cam into action and as the cams are all connected they all go into action
simultaneously.
.
Fig. 9 shows an ordinary hydraulic cylinder with multiplying sheaves M, M.
Additional sheaves m m are fixed to the-crosshead and cylinder or other fixed
support and a light rope passed round them and carried over an overhead sheave and
connected to a lever or other arrangement connected with the cams.
3. The third part of our invention relates to auxiliary safety apparatus whereby
the cage can be gradually brought to rest independently of the main safety apparatus
as described in the second part of our invention and also independently of the con-
trolling rope or lever.
In carrying out this part of our invention we do not use serrated cams but use
cams with a smooth surface or blocks which may be wedged up against the runners.
These cams or blocks are put into action by a toothed or fluted wheel driven by being

page_text: pressed against the runners and which by means of a suitable mechanism presses the
cams or blocks against the runners with increasing pressure until sufficient friction has
been set up to stop the cage.
In one form of this part of our invention this wheel is mounted in such a manner
that any resistance to its revolution only tends to press it more firmly against the
runner when the cage is descending. It is put into action by a lever having a weight
or spring ordinarily kept out of action by being held by a trigger. This trigger
may be released from the interior of the cage by attaching a suitable cord or rod
thereto or it may be released by a centrifugal governor attached either to the cage
or to some part of the hoist, "well" preferably at the top of the framing. When this
governor is attached to the cage it is driven either by a special rope or ropes suitably
secured at the top and bottom of the hoist "well" or by means of the controlling
valve rope and is so arranged that when its revolutions exceed a certain speed and
the centrifugal force takes effect it by means of a cord or other attachment releases
When
the trigger aforementioned and allows the cams or blocks to come into action.
the governor is attached to the framing at the top of hoist "well" it is driven by a
rope one end of which is attached to the trigger aforementioned on the cage and the
other end to a counterweight to keep the rope taut. The trigger in this case is
provided with sufficient resistance to prevent its withdrawal by the pull on the rope
caused by the friction of governor spindle and attachment when the cage is descending.
When the governor comes into action it arrests the rope by means of a suitable
brake or like arrangement and so releases the trigger.
In another form of this part of our invention we mount the governor on the cage
and drive it by means of a toothed or fluted wheel kept constantly in contact with
one of the runners by a spring or other suitable means. The spindle on which the
wheel is mounted is provided with a clutch put into action by the said governor and
by means of which the motion of the spindle puts the cams or blocks into action by
suitable gear. This clutch may also be provided with a lever or other convenient
mechanism for putting it into action from the interior of the cage independently. of
the governor.
One form of apparatus is shown in Figs. 6, 7 and 8 and the governor for releasing
it in Figs. 10 and 11. Fig. 12 is a modification.
The guides N are provided with set screws n to take up the wear and also enable
them to be kept close up to runners to prevent chattering. One of these guides at
each side is provided with wedges O connected by rods o with a central lever o by
means of which the wedges can be made to press the guides tightly against runners
so as to stop the cage. The lever o' is pivotted at o' and put into action by a cord på
passing over guide sheave pl and wound round a drum p secured to a fluted wheel P.
This wheel is pivotted on the short arm of a lever q which is pressed down by its
own weight and spring when released from trigger Q by cord and presses the
fluted wheel P against the runner.
In Figs. 10 and 11 a governor of ordinary construction S is mounted overhead
and driven by belt from spindle of overhead sheave, when it comes into action it
releases the trigger S which holds lever T up. This lever T is pivotted at t and
carries on its short arm a sheave R over which runs a cord one end of which is
connected to trigger in cage (Fig. 7) and the other provided with a counterbalance.
A brake block is fixed close to sheave R so that when lever T is released by
governor it causes the sheave R or cord thereon to press against this brake block
and by arresting the motion of said cord withdraw the trigger Q (fig. 7) and so put
the gear into action.
In fig. 12 the governor is mounted on cage. U are the governor balls with arms
pivotted at u to the spindle and provided with short arms u¹ with pins working in
slots of lugs connected to disc V. A sleeve W slides loosely on shaft and is con-
nected to balls U by rods w. A spring w¹ presses against this sleeve and has an
adjusting nut w by means of which the speed of action of governor may be varied.
The disc V slides on feathers on spindles and is toothed to engage with disc
when

page_text: pressed into action by governor. The disc runs loose on spindle and has formed
with it a pinion X gearing into wheel a keyed on a screw nut operating screw
connected to the central lever o¹ of wedge gear. Y is a fluted wheel which drives
the governor, it is mounted in a bearing y with spring y' to keep it against the
runner.
The effect of this third part of our invention is that the cage may be stopped at
will from the cage independently of all other means and will be brought to a standstill
gently and gradually either by this said means or by the governor which will
effectually prevent undue speed of descent which would be caused for instance by the
breaking of the cylinder or connections in which case their might remain sufficient
pull on the lifting ropes to prevent the ordinary safety gear coming into action.
We may use any well known form of governor in place of those shown and drive
the same in any convenient way.
We may substitute other methods for the one shown in figs. 6 and 7 for com-
municating the motion of fluted wheel to wedges such as for instance screws similar
to those shown in fig. 12.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. The construction of valve for hydraulic lifts with an extended lap on the
pressure side substantially as described and shown in fig. 1 and for the purposes set
forth.
2. The construction of valve for hydraulic lifts, with an extended lap on the
exhaust side substantially as described and shown in fig. 2 and for the purposes set
forth.
3. The combination of weighted levers and stops substantially as described and
shown in figs. 3 and 4 of sheet 1 of the accompanying drawings and for the purposes
set forth.
4. In valves for hydraulic lifts, operating the same by a combination of weighted
levers and stops so arranged that the downward motion of lever to which the hand
rope is fixed will open the valve to cause the lift to travel in the desired direction
until a certain depression of lever is attained and the valve wide open after which
any further depression will close said valve for the purposes described.
5. The method of operating valve rope by means of a lever and sheaves operating
a single valve rope substantially as shown in fig. 5 and described.
6. In safety gears for lift cages having four ropes, the coupling together of the
four cams combined with the means for operating all four cams simultaneously on
the breaking of one or more ropes substantially as shown and described.
7. In safety-gears for lift cages (in addition to the cams put into action on the
breaking of lifting ropes) the construction and arrangement of smooth cams or
blocks put into action by a toothed or grooved wheel which is pressed against the
runners by a weighted or spring-loaded lever ordinarily kept out of action by being
held by a trigger which may be released by hand from inside the cage or by a
centrifugal governor substantially as described and for the purposes set forth.
8. In safety-gears for lift-cages (in addition to the cams put into action on the
breaking of lifting ropes) the construction and arrangement of smooth cams or blocks
put into action by a screw or other appliance driven by a clutch or the like put into
action by a centrifugal governor on a shaft driven by a toothed or grooved wheel
constantly pressed against the runners or driven by a fixed cord or the like substantially
as described and for the purposes set forth.
9. The arrangement and combination of serrated cams and connecting and operating
mechanism substantially as shown in figs. 6, 7 and 8.
10. The arrangement and combination of wedge blocks and levers together with
the grooved or toothed wheel and connections substantially as shown in figs. 6, 7
and 8.

page_text: 11. In safety-gears for hydraulic lifts the combination with an ordinary cylinder of
extra sheaves for the safety rope substantially as shown in fig. 9 and as hereinbefore
described.
12. The arrangement of safety apparatus substantially as shown in Fig. 12 or any
mere modification thereof.
Dated this 3rd day of September 1889
HENRY CLAUDE WALKER.
ROBT. CAREY.