Improvements in Safety Apparatus for Lifts.
Year: 1899

page_text: Date of Application, 11th Apr., 1899-Accepted, 13th May, 1899
COMPLETE SPECIFICATION.
Improvements in Safety Apparatus for Lifts.
We, GEORGE Fox 2nd, Civil Engineer, of 304, West 32nd Street, New York
City Borough of Manhattan, in the County and State of New York, United
States of America, and GARRET SNEDEKER WRIGHT, Mason and Builder, of
344, West 22nd Street, New York City aforesaid, do hereby declare the nature
of this invention and in what manner the same is to be performed, to be parti-
cularly described and ascertained in and by the following statement:-
-
The object of the invention is to provide an improved safety attachment for
lifts which is simple and durable in construction, very effective in operation,
and arranged to securely brake or lock the cage in place, in case of accidental
breaking of the hoisting rope or other means employed for raising or lowering
the cage.
The invention consists of novel features and parts and combinations of the
same, as will be fully described hereinafter and then pointed out in the claims.
A practical embodyment of the invention is represented in the accompanying
drawings forming a part of this specification, in which similar letters of reference
indicate corresponding parts in all the views.
Figure 1 is a side elevation of the improvement as applied and with parts in
section;
Figure 2 is a sectional front elevation of the same;
Figure 3 is a plan view of the same;
Figure
4 is an enlarged sectional side elevation of the governor;
Figure 5 is a sectional side elevation of a modified form of the improvement;
and
Figure 6 is a front view of another modified form of the improvement.
The cage A is provided with the usual means for raising or lowering it and
for stopping or starting the cage; and the cage is also provided on its sides with
the usual top guides B and the bottom guides B₁, which straddle posts C, made of
channel beams set on the top of one another, the sides extending inward towards
the cage, as will be readily understood by reference to Figure 2. The guides B
and B extend to the outer faces of the sides of the channel beams and said outer
sides may be lubricated so as to insure a smooth running of the cage.
At the inside of the channel beams and between the sides thereof, extend
cams D, secured on the ends of a shaft 11, journalled in suitable bearings attached
to the cage A, preferably at the under side thereof, as is plainly indicated in
Figures 1 and 2. Each of the cams D normally travels freely up and down in the
corresponding channel beam; that is, the cams are moved bodily with the cage A,
and the cam surfaces are normally out of engagement with the inner faces of
the sides of the channel beams, so as not to in any way interfere with the free
travel of the cage, as long as the latter moves at a normal rate of speed.
In case of an accident the cams D are actuated so as to impinge with their
cam faces against the inner faces of the sides of the channel beams, and as these
sides are not lubricated at their inner faces, it is evident that the cams brake the

page_text: cage on which they are carried, and finally bring the cage to a stop. The cams D
may be operated manually or automatically, or both.
As shown in the drawings, one of the cams is connected near its end by a
rope E with a lever F fulcrumed on the cage A and under the control of the
attendant thereof, said lever being provided with the usual locking lever Fl
engaged a segment F2, for normally holding the lever F in a locked position.
In case the hoisting means for the cage breaks or becomes disarranged or in-
jured, then the operator, by throwing the lever in the direction of the arrow a¹,
causes the rope E to exert a pull on the cam D and swing the same and the other
cam, so as to bring their cam surfaces in frictional contact with the inner faces
of the sides of the channel beams, to brake the cage and bring the same to a
stop.
The automatic device for actuating the cams in the manner described, is
arranged as follows:
On the rope E is attached the lower end of a rope G, extending upwardly on
one side of the cage, to connect with a drum H, on which the rope is adapted to
wind up to pull on the rope E, so as to swing the cams into frictional contact
with the sides of the channel beams. The drum H is secured on one end of a
shaft H, journalled in a suitable bracket A attached to the top of the cage,
and the other end of the shaft H¹ is provided with a pinion H2, normally out of
mesh with a bevel gear wheel I, secured on the upper end of the shaft I² of a
governor I carried by the bracket A. (See detail construction in Figure 4).
The shaft I is connected with the weighted levers 13 of the governor, said levers
being pivoted on a sleeve It, mounted to turn in suitable bearings in the
bracket A and in which the shaft 12 is mounted to slide vertically, said shaft
rotating, however, with the sleeve It. The lower end of the sleeve is provided
with a bevel gear wheel 1, in mesh with a bevel gear wheel J secured on a
shaft J carrying a pulley J2 on which winds, several times, a rope K, secured at
its upper and lower ends in the top and bottom of the lift shaft, suitable devices
being provided at the ends of the rope, for keeping it tight in the shaft. As the
cage A ascends or descends, the pulley J2 is rotated by the winding and un-
winding of the fixed rope K, and the rotary motion of the drum J2 is trans-
mitted by the shaft J and gear wheel J to the gear wheel I5 and the sleeve I*,
which rotates the shaft I2, mounted to slide in said sleeve.
In case the cage A, for any cause whatever, travels beyond the normal rate of
speed, then an increased speed is given to the drum J2 and the parts connected
therewith, so that the weighted levers I3 of the governor fly outward to such an
extent as to raise the shaft 12 and bring the bevel gear wheel I in mesh with
the pinion H. When this takes place the shaft H' is rotated, and consequently
the rope G is wound up on the drum H, to exert a pull on the rope E and swing
the cams D in frictional contact with the sides of the channel beams, to brake
and stop the cage, as previously described. Instead of rotating the drum J2 by
winding the rope K several times around the drum, I may employ the device
shown in Figure 6, in which the rope passes over a pulley J3 on the shaft J,
connected with the governor as described, said rope also passing under a pulley J³,
journalled in bearings J6 held on a spring J7 attached to the cage A, to give the
desired tension to the rope K, to rotate the pulley J3 and shaft J, upon the ascent
or descent of the cage A.
Instead of using the hand lever F for manipulating the cams D as described,
I may employ the construction shown in Figure 5, in which a shaft D³, carrying
cams D2 is provided with a segmental worm wheel L, in mesh with a worm L
secured on a vertically-disposed shaft L2, journalled in suitable bearings attached
to the cage A. The upper end of the shaft Lº carries a bevel pinion L³, in mesh
with a bevel gear wheel N₁ secured on a shaft N, carrying a hand wheel N2 under
the control of the operator, so that when the latter turns the hand wheel, a
rotary motion is given to the shaft L2 by the gear wheel N¹ and pinion L³, to
cause the worm wheel L¹ to rotate the worm wheel L and the shaft D³, to swing

page_text: the cams D2 in frictional contact with the inner faces of the sides of the channe!
beams.
We do not limit ourselves to the particular means described for carrying the
invention into effect, as it is evident that the construction may be varied, without
deviating from the invention.
It will be seen that the device is very simple and durable in construction, is
not liable to get out of order, and is always ready and completely under the con-
trol of the operator of the cage; and is also, in addition, controlled by the speed
of the cage, so that accidents to human beings travelling in the cage, are rendered
almost impossible.
If desired, only a single cam may be employed, or a plurality of sets of such
cams may be used and connected together by suitable means, so that all the cams
move into action as soon as an accident occurs.
Having now particularly described and ascertained the nature of the said in-
vention, and in what manner the same is to be performed, we declare that what
we claim is: -
1) The channel beams forming guides for the lift cage and at the same time
braking surfaces for the cams carried by the lift cage, substantially as and for
the purpose set forth.
2) The cams carried by the lift cage to engage the channel beams and con-
trolled either by a hand lever, or by a governor actuated by the cage according
to the speed thereof, or by both, substantially as and for the purpose set forth.
3) The governor carried by the lift cage and operating to shift a gear wheel (I¹)
into driving engagement with a pinion (H2) to turn the drum (H) and throw the
braking cams (D) into action, substantially as and for the purpose set forth.
Dated this 11th day of April 1899.
-A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.