Elevator Safety Attachments.
Year: 1895

page_text: Elevator Safety Attachments.
I, CHARLES BAGOT LABATT, 44 E. 9th Street, New York City, United States
of America, Attorney-at-Law do hereby declare the nature of this invention to be
as follows:-
My invention relates to a safety attachment for elevators and has for object to
provide a simple economic and durable means whereby in the event that the hoist
rope of the elevator should break or part, or in the event that the speed of the cage
should be much more than a predetermined rate, safety catches will be brought
into the path of the cage to instantly stop the travel thereof and hold the cage
stationary. Another object of this invention is to provide a device for accomplishing
the above-named objects capable of being expeditiously and conveniently applied
to any elevator shaft and any elevator cage, the mechanism being brought
automatically into action either directly through the movement of the cage itself,
or by controlling devices connected with the bearings of the drum supporting
the cage.
The invention consists in the novel construction and combination of the several
parts, as will be hereinafter fully set forth,-and it is designed in a measure as an
improvement upon that for which Letters Patent were granted to me October 7th
1893, No. 18816, wherein the safety catch was operated only upon the breakage of
the hoisting rope.
Preferably at one side of the elevator shaft, a vertical bar or beam is
supported, and said bar or beam is provided with recesses at frequent intervals
therein, while in each recess a safety catch is fulcrumed, the catch being
practically in the form of a latch comprising a body portion, which is normally
held entirely within the recess it is intended to occupy, and a shank ordinarily
somewhat of a hook-like construction, which extends out beyond the outer face
of the recess, and when the hook or shauk portion of the catch is liberated, or is
forced upward, the body portion will be carried outward and downward from the
recess in which the latch is placed, in the path of the descending cage or car,
so as to support the latter and prevent it from travelling further downward.
The latch beam is further provided with a series of eyes upon its inner face, and
through these eyes a trip-rope is made to loosely pass, and this rope carries at
proper intervals in its length a series of trip blocks which are recessed upon their
inner faces, and a trip block is located opposite the shank portion of each of the
latches, the said shanks of the latches entering the recesses in the blocks and
normally these blocks maintain the latches wholly out of the path of the car
or cage.
In some cases the above described tripping-blocks are replacel by a series of
lever-arms connecting the trip-rope with the latches, a lever-arm being in such
cases suitably pivoted with respect to each latch, and the trip-rope being passed
through an eye formed in one end of said lever-arm, the other end of which engages
the shank of the latch.
The trip-rope in one arrangement is carried upward over a pulley located at the
upper portion of the shaft and is then connected with one end of a plunger
controlled by a spring or weight, or its equivalent, the spring serving to normally
exert downward tension on the upper end of the trip-rope, and thereby cause the

page_text: trip-blocks to be elevated to throw the latches in the path of the cage or car; but
the spring is prevented uormally from so acting by forming lugs upon the periphery
of the pulley to receive between them one end of a lever fulcrumed in a suitable
hanger which may be secured to a support at the top portion of the elevator shaft;
and when the speed of the car shall have increased beyond a predetermined degree,
the lever is adapted to be engaged by the arms of a governor of any well-known
type and in this event said lever is disengaged from the said pulley by a blow
from the arm of the governor, and the spring or weight acting will bring the trip-
blocks to a position to throw inward the safety catches or latches.
Upon suitable supports located in the upper portion of the elevator shaft, pillars
are supported, and in each of said pillars a box has vertical sliding movement.
These boxes are made to journal a shaft, upon which the drum-wheel carrying the
hoisting or supporting rope of the elevator car or cage is securely fastened, and
preferably at one end of this shaft a mitre-gear is secured, which meshes with a
similar gear secured on the shaft operating the governor.
A lever is fulcrumed, usually between its centre and one of its ends upon a
hanger extending downwards from the top of the shaft ; and at the shorter end of
this lever a rod is located, carrying a predetermined amount of weight, while the
opposite or longer end of the lever may be and preferably is connected with
the trip-rope by means of a branch and one of the boxes in which the drum
shaft is journaled is connected with the aforesaid lever by means of a link or its
equivalent.
Thus it will be observed that should the speed of the car or cage be unduly
accelerated the governor arms will be made to expand and the trip lever connected
with the pulley will release said pulley and as hereinbefore stated, the safety
latches or catches will act to stop the car.
In the event that the hoisting or elevating rope should break, the weight will be
sufficient to draw down the short end of the longer lever, the drum shaft rising in
its bearings and allowing the lever to move upward at its longer end, and as that
end is carried in an upward direction it will simply slack that portion of the trip
cable or rope passing over the pulley, but will act upon the balance of the cable to
draw upward the trip blocks in a position to throw the safety catches or latches
out into the path of the car.
Thus it is evident that no matter whether the hoisting cable should break or
whether the speed of the car should be unduly increased the latches will serve to
stop the car until any accident that may have occurred to the mechanisın may be
repaired.
It will be seen from the foregoing description that the mechanism employed to
actuate the trip rope and catches in the event of the hoisting cable breaking, is
independent of that which operates the said devices in case of excessive speed of
the car and cable. One set of mechanism or the other may if desired be applied to
an elevator separately, instead of both in combination as above described. For
operating the stopping devices only on the breaking of the cable, the parts
required will be :—
The double armed lever and fulcrum, the rod and weight, link, pillars supporting
vertically sliding journal box, and drum wheel shaft turning in latter, arranged
as described; the trip-rope, trip-blocks and latches being used alike in the
combination, or in either of the two arrangements.
The parts necessary for operating the stopping devices only in case of excessive
speed will be-The mitre gearing, governor, and shaft, the pulley, extension of
trip-rope, rod and plunger (or weight), lugs, trip-lever and hanger.
By a modification in that portion of the mechanism whereby the trip cable is
brought into action by the acceleration of the speed of the car, may dispense
In this event
with the hanger arranged at the top of the shaft to carry the lever.
the actuating lever is fulcrumed upon a standard located on one of the pillars or
pedestals supporting the boxes of the drum shaft. The governor is driven in the
manner hereinbefore described, and upon the opposite pedestal a post is secured

page_text: which extends upward through an opening made in the lever, the said opening
being of much greater diameter than the diameter of the post.
A lock-lever is fulcrumed upon the upper end of the post, and is adapted to rock
on its fulcrum and has an opening made in it through which one end of the lever
passes, the opening being of sufficient size to permit of considerable side movement
on the part thereof. Under this construction a tongue is projected downward from
the lever and normally rests upon the top of the actuating lever, holding the same
in a horizontal position and against the influence of weights carried by a rod
connected with one end of the lever. At the opposite end of the lever the trip-rope
is secured, to which the trip-blocks are attached; and upon the lower end of the
lock-lever an arm or its equivalent is placed which when the speed of the car is
beyond a predetermined degree or rate, the governor arms in expanding will engage
and therefore rock the lock-lever to one side or the other to such an extent as to
be
release the actuating lever permitting its weights or
a spring which nay
substituted for them to draw down the end of the lever with which the weight is
connected, thereby elevating the opposite end and causing the safety-latches to
drop in the path of the car. This arrangement dispenses with the pulley, rod and
plunger, trip lever and lugs previously described.
In another arrangement for operating the trip-rope and latches upon the
severance of the hoisting cable, which may either be employed separately or in
combination with mechanism for operating the said devices in case of undue
acceleration of the speed of the car, a lever pivoted at one end may be adapted to
raise the trip-rope with the main shaft when the latter is relieved of the weight of
the cage, by means of an adjustable spring secured between the free end of the
lever and the top of the elevator shaft, or by an equivalent device. The trip-rope
in this case is connected to the lever at or near its free end, and the safety latches
or stopping devices, as well as the sliding journal-box are arranged and operated
similarly to those previously described. To limit the extent to which the main-
shaft and trip rope are drawn upwards, the movement of the actuating lever may
be restricted in this arrangement and also (if required) in other constructions
herein described by means of a suitable check rod secured upon the lever and
passed through an orifice formed in the top of the elevator shaft.
In any arrangement I may use one or more fulcrumed levers counterbalanced or
retained by weights or springs for the purpose of actuating the stopping devices.
When two levers are used they may be arranged one over each end of the
main-shaft.
The lever or levers may otherwise be so arranged as to push the shaft upward
when the hoisting cable breaks, instead of pulling it upward as above described.
By another arrangement of a double-armed lever the trip-rope may be utilized
for suspending the weight or weights whereby the shaft is counterbalanced, the
fulcrum in this case being placed between the points of suspension of the trip-rope,
and of the link or attachment for lifting the shaft; a spring may be adapted to
react upon the lever at a convenient point so as to assist the weight in lifting
the shaft.
The devices employed for operating the latches in this construction will be of
the form of pivoted lever-arms, already described, connecting the trip-rope with the
latches, whereby the downward movement of the said rope is caused to throw
upward the shanks of the latches.
In another modification movement is imparted to the governor directly from the
car or cage. In this event the hoisting drum may be mounted in the usual manner,
The governor
and a hoisting cable is attached to the car or cage as ordinarily.
shaft is provided with a bevel gear driven from a like gear secured on a shaft
independent of the drum shaft, and the said independent shaft carries a pulley over
which a cable is passed. One end of this cable is secured to the elevator cage or
car usually adjacent to the hoisting cable, while its other end is attached to a
spring-controlled drum of any approved construction, or the equivalent of said
drum secured to the car or cage. This drum may be provided with a spring

page_text: cage or
which will be wound up as the cable unreels from the drum, which will be on the
downward movement of the
car; therefore, on the upward movement
of the said cage or car the spring of the drum will cause the cable to be wound
thereon and as long as the speed of the car is within predetermined bounds the
governor will not act upon the trip-mechanism which is a duplicate of that
described in the first arrangement and correspondingly designated; but when the
speed of the car is unduly increased, the governor will release the pulley of the
trip mechanism and permit the spring or a corresponding weight, to draw upward
the rope and throw inward the latches.
In order to minimise the shock caused by the cage coming into contact with the
latches or stops when in operation, I attach an elastic buffer consisting of some
preparation of caoutchouc, gutta-percha or other suitable material to the car or
cage; or I may make the buffer in the form of a metallic spring or pneumatic
cushion, the whole being so arranged that in the event of the cage or car falling,
the elastic cushion or buffer will come into contact with the latch and thus
considerably lessen the force of the shock.
Or, a double floor with elastic support, may if preferred, be used in lieu of the
foregoing buffer devices for the purpose of absorbing and reducing the shocks
sustained by the car when its descent is suddenly arrested by the catches.
Dated this Twenty-ninth day of May 1895.
I, CHARLES BAGOT LABATT, late of 44 E. 9th Street New York City, United
States of America, at present residing at 56 Beaver Street New York, U.S.A.,
Attorney-at-Law, 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 :--
My invention relates to a safety attachment for elevators, and it has for object
to provide a means simple, economic, and durable whereby in the event the hoist-
rope of the elevator-cage should break or part, or in the event that the speed of
the cage should be much more than a predetermined rate, safety-catches will be
automatically brought into the path of the cage to instantly stop the travel thereof
and hold the cage stationary.
Another object of this invention is to provide a device for accomplishing the
above-named objects capable of being expeditiously applied to any elevator-shaft
and any elevator-cage, the mechanism being brought automatically into action
either directly through the movement of the cage itself or by controlling devices
connected with the bearings of the drum supporting the cage.
The invention consists in the novel construction and combination of the several
parts, as will be hereinafter fully set forth, and it is designed in a measure
as an improvement upon that for which Letters Patent were granted to me
October 7, 1893, No. 18816, wherein the safety-catch was operated only upon the
breakage of the hoisting-rope.
Reference is to be had to the accompanying drawings, forming a part of this
Specification, in which similar figures and letters of reference indicate corresponding
parts in all the views.
Figure 1 is a vertical section through a portion of the elevator-shaft, illustrating
the means for bringing the safety device into requisition either through increase of

page_text: speed on the part of the cage or by reason of a breakage or fracture in the
supporting-cable.
Figure 2 is a vertical section taken substantially on the line 2—2 of Fig. 1.
Figure 3 is a horizontal section taken practically on the line 3-3 of Fig. 1.
Figure 4 is a partial vertical section through an elevator-shaft, illustrating a
modification in the trip device brought into action by increase of speed on the part
of the car or cage.
Figure 5 is a section taken substantially on the line 5-5 of Fig. 4.
Figure 6 is a partial vertical section through an elevator-shaft, illustrating a
slight modification in the safety-catch controlling mechanism, wherein said
mechanism is controlled directly from the cage or car, and shewing the bottom of
the cage provided with a buffer.
Preferably at one side of the elevator-shaft A, a vertical bar or beam 10 is
supported, and said bar or beam is provided with recesses 11 at frequent intervals
therein, while in each recess a safety-catch 12 is fulcrumed the catch being
practically in the form of a latch comprising a body portion, which is normally
held entirely within the recess it is intended to occupy, and a shank 11 a, ordinarily
somewhat of hook-like construction, which extends out beyond the outer face of
the recess, as is best shewn in Fig. 1, and when the hook or shank portion of the
catch is liberated or is forced upward the body portion will be carried outward and
downward from the recess in which the latch is placed into the path of the
descending cage or car, so as to support the latter and prevent it from travelling
farther downward. The latch-beam is further provided with a series of eyes 12 a
upon its inner face, and through these eyes a trip-rope 13 is made to loosely pass,
and this rope carries at proper intervals in its length a series of trip-blocks 14,.
which are recessed upon their inner faces, and a trip-block is located opposite the
shank portion, 11 a, of each of the catches 12 as shewn, also in Fig. 1, the said
shanks of the catches entering the recesses in the blocks, and normally these blocks
maintain the catches wholly out of the path of the car or cage.
The trip-rope 13 is shewn in Figs. 1, 2, and 3 as being carried upward over a
pulley 15, located at the upper portion of the shaft, and is then connected with one
end of a plunger 17, controlled by a spring 18, a weight or its equivalent, the
spring serving to normally exert downward tension on the upper end of the trip-
rope, and thereby cause the trip-blocks to be elevated to throw the catches 12 in
the path of the cage or car; but the spring 18 is prevented normally from so
acting by forming lugs 19 upon the periphery of the pulley 15, to receive between
them one end of a lever 20, fulcrumed in a suitable hanger 21, which may be
secured to a support at the top portion of the elevator-shaft, and when the speed
of the car shall have increased beyond a predetermined degree, the lever 20 is
adapted to be engaged by the arms of a governor 22,-the latter being of any
well-known type, and in this event the said lever is disengaged from the said
pulley, and the spring or weight 18 acting will bring the trip-blocks to a position
to throw inward the safety-catches and stop the car.
Upon suitable supports B, located in the upper portion of the elevator-shaft,
pillars 23 are supported, and in each of the said pillars a box 24 is arranged and
has vertical sliding movement. These boxes are made to journal a shaft 25, and
on the said shaft the drum-wheel 26, carrying the hoisting or supporting rope 27
of the elevator-car or cage is securely fastened, and preferably at one end of this
shaft a mitre-gear 28 is secured which meshes with a similar gear 29, secured on
the shaft 30, operating the governor.
A lever 31 is fulcrumed usually between its centre and one of its ends upon a
banger 32, extending downward from the top of the shaft, and at the shorter end
of this lever a rod 33 is located, carrying a predetermined amount of weight 34, while
the opposite and longer end of the lever may be and preferably is connected with
the trip-rope 13 by means of a branch 13 a-as is best shewn in Fig. 2, and one
of the boxes 24, in which the drum-shaft 25 is journaled, is connected with the

page_text: aforesaid lever 31 by means of a link 35 or its equivalent. Thus it will be observed
that should the speed of the car or cage be unduly accelerated the governor-arms
will be made to expand,-
-as shewn in dotted lines in Fig. 1,-and the trip-lever 20
connected with the pulley 15, will release said pulley, and-as heretofore stated-
the safety-latches or catches will act to stop the car.
In the event that the hoisting or elevating-rope 27 should break, the weight 3+
will be sufficient to draw down the short end of the longer lever 31, the drum-shaft
rising in its bearings as the lever swings, and as the free end of the lever is carried
in an upward direction it will simply slack that portion of the trip-cable or rope
passing over the pulley 15, but will act upon the balance of the cable to draw
upward the trip-blocks in a position to throw the safety-catches out into the path
of the car. Thus it is evident that no matter whether the hoisting-cable should
break or whether the speed of the car should be unduly increased, the catches will
serve to stop the car until any accident that may have occurred to the mechanism
may be repaired.
In Fig. 4 I have illustrated a modification in that portion of the mechanism
whereby the trip-cable 13 is brought into action by the acceleration of speed on
the part of the car. In this event the actuating lever 31 a is fulcrumed upon a
standard 36, located in one of the pillars or pedestals 23, in which the boxes of
the drum-shaft are placed. The governor is driven in the manner heretofore
described, and upon the opposite pedestal 23 a post 37 is arranged and passed
through a vertical opening in the end of the pedestal, whereby it may be fixed to
the box 24 thereof. The two boxes 24 and their shaft 25 are capable of vertical
movement in the pedestal 23, and when the rope 27 is intact they are forced to the
limit of their downward movement by the weight of the car. The upper end of
the post 37 is passed through an enlarged opening 38, formed in the lever 31 a.
As shewn in Fig. 5, a lock-lever 39 is fulcrumed upon the upper end of the post,
and this lock-lever is adapted to rock upon its fulcrum and has an opening 40 made
in it through which one end of the lever 31 a passes, the opening being of sufficient
size to permit of considerable side movement on the part thereof. Under this
construction a tongue 41 is projected downward from the lever, and the tongue
normally rests upon the top of the lever 31 a, holding the same in a horizontal
position and against the influence of weights 42, carried by a rod 43, connected
with one end of the lever. At the opposite end of the lever the trip-rope 13 is
secured, to which the trip-blocks 14 are attached and upon the lower end of the
lock-lever 39 an arm 44 or its equivalent is placed, which-when the speed of the
car is beyond a predetermined degree or point-the governor-arms in expanding
will engage, and therefore rock the lever 39 to one side or the other to such au
extent as to release the actuating-lever 31 a, permitting its weights 42, or a spring
which may be substituted for the weights, to draw down the end of the lever with
which the weight is connected, thereby elevating the opposite end and causing the
safety-latches to drop in the path of the car. When however the rope 27 breaks,
the weight of the car being no longer applied to the shaft 25, the same together
with its box 24, will be lifted by its weights 42 acting through the medium of the
lever 31 a, and rod or standard 37, it being understood that these two parts are
connected by the engagement of the lever 31 a and arm 41 of the lever 39.
the lever 31 a swings upward it raises the rope 13, and operates the catch-
devices 12, as will be understood. Thus it will be seen that the lever 31 a may be
operated in two ways-by causing the arms 41 to be disengaged therewith and by
removing the weight of the car from the shaft 25-in both of which cases the
weights 42 will lift the lever and positively operate the catches 12.
As
In the construction shewn in Fig. 6, the movement is imparted to the governor
directly from the car or cage. In this event the hoisting-drum 44b may be
mounted in the usual manner, and a hoisting-cable 44 a is attached to the car or
cage as ordinarily. The governor-shaft 45 is provided with a bevel-gear 46, driven
from a like gear 47, secured on a shaft 48, independent of the drum-shaft, and the

page_text: shaft 48 carries a pulley 49, over which a cable 50 is passed. One end of this
cable is secured to the elevator cage or car usually adjacent to the hoisting-
rable 44 a, while the other end of the cable 50 is attached to a spring-controlled
drum 51, of any approved construction, or the equivalent, of said drum, the latter
being secured to the car or cage. This drum may be provided with a spring, which
will be wound up as the cable 50 unreels from the drum, which will be on the
downward movement of the cage or car. Therefore on the upward movement of
the said cage or car the spring of the drum 51 will cause the cable 50 to be wound
thereon, and as long as the speed of the car or cage is within predetermined bounds
the governor will not act upon the trip-mechanism which is a duplicate of that
shewn in Fig. 1, and correspondingly designated; but when the speed of the car
or cage is unduly increased the governor-arms will release the pulley 15 of the
trip-mechanism, and permit & spring 18,-or a corresponding weight,-to draw
upward the trip-rope and throw inward the latches.
It is obvious that the sheave 446 may be replaced by the wheel 26, boxes 24,
lever 31, and the attending mechanism, and indeed, in practice this will be desirable,
since it may not be well to rely solely on the devices shewn in Fig. 6 for acting on
the breaking of the hoisting-rope. In this event the said parts will be arranged
and will operate precisely as in Figs. 1, 2, and 3, and will be supplemental to the
parts illustrated in Figure 6.
In order to minimise the shock caused by the cage coming into contact with the
latches or stops when in operation, I attach an elastic buffer consisting of some
preparation of caoutchouc, gutta-percha or other suitable material to the car or
cage; or I may make the buffer 52,-Fig. 6,-in the form of a metallic spring or
pneumatic cushion, the whole being so arranged that in the event of the cage
or car falling, the elastic cushion or buffer will come into contact with the latch
and thus considerably lessen the force of the shock.
Or, a double floor with elastic support may, if preferred, be used in lieu of the
foregoing buffer-devices for the purpose of absorbing and reducing the shocks
sustained by the car, when its descent is suddenly arrested by the catches.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:
1. The combination of an elevator car, a safety catch, a rope connected to said
catch mounted at the side of the shaft and off the car, means tending to move said
rope to throw the catch into operative position, means for holding the rope against
movement, and a governor controlling said means, substantially as described.
2. The combination of an elevator car, a safety catch, a rope connected thereto,
means for drawing on the rope, a drum over which the rope is wound, a stop for
the drum, and a governor controlling the stop, substantially as described.
3. The combination of an elevator car, a safety catch, a rope connected to the
catch, a drum over which the said rope is wound, a spring connected to the rope,
a lever capable of holding the drum, a governor coutrolling the lever, a second
lever connected to the rope of the catch, and a shaft carrying the elevator sheave
and vertically movable, the said shaft having a connection with the second lever,
substantially as described and for the purposes specified.
4. The combination of an elevator car, a safety catch, a rope connected to the
catch, a drum over which the rope is wound, a spring connected to the rope, a lever
capable of holding the drum, and a centrifugal governor controlling the lever and
controlled by the movements of the elevator car, substantially as described.
5. The combination with an elevator car, of a safety catch formed with a pro-
jecting shank, a trip-lock having a recess receiving the shank of the safety catch, a
rope connected to the trip block, and meaus for drawing on the rope, substantially
as described.
6. The combination with an elevator car, of a recessed beam, a safety catch
pivoted in the recess thereof and having a lateral projecting shank, a trip block

page_text: having an indentation or recess receiving the shank, a rope connected to the trip
block, and means for drawing on the rope, substantially as described.
7. In an elevator, the arrangement on the underside of the car or cage of a
spring buffer, or elastic cushion, for the purposes and as specified.
8. In an elevator car, the combination with a vertically movable elevator shaft,
of means for automatically operating the trip mechanism upon the breaking of the
hoisting cable, as described.