Elevator Brakes.
Year: 1898

page_text: Date of Application, 24th June, 1898-Accepted, 6th Aug., 1898
COMPLETE SPECIFICATION.
Elevator Brakes.
I, GEORGE BROWN, residing at No. 706, East 137th Street, New York, in the
County of New York, and State of New York, United States of America, Piano
Maker, 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 relates to elevators, and the object thereof is to provide an
elevator car with improved suspending devices, and an improved stop or brake
mechanism whereby the elevator will be held, and the dropping or falling thereof
prevented, in case the main suspension cable by which it is raised and lowered
should break or be disconnected therefrom.
The invention is fully disclosed in the following specification of which the
accompanying drawing forms a part, in which:
Fig. 1, is a side view of an elevator car provided with my improvement, and
showing parts of the side walls of the elevator shaft;
Fig. 2, a plan view of the brake mechanism which I employ;
Fig. 3, a partial section on the line 3-3 of Fig. 2;
Fig. 4, an edge view of a locking disk which forms a part of my improved brake
mechanism;
Fig. 5, a side view thereof;
Fig. 6, an inside view of one of a pair of double pulleys which form a part of
said brake mechanism, and showing the locking disk mounted therein;
Fig. 7, a side view of a wheel provided with a ratchet hub, which also forms a
part of said mechanism; and,
Fig. 8, a side elevation of a lever which also forms a part of said mechanism.
In the drawing forming part of this specification the separate parts of my improve-
ment are designated by the same numerals of reference in each of the views, and
in said drawing, I have shown at 5, the opposite side walls of an elevator shaft, and
at 6 an elevator car mounted therein, and said elevator car is provided with a top
cross beam 7 which forms a part of the frame thereof, and this cross beam 7 is
preferably of the form in cross section shown in Fig. 3, the side walls thereof being
inwardly and upwardly inclined.
Connected with the cross beam 7 are two vertical side plates 8, said plates being
connected with said beam by a bolt 9, provided at one end with a nut 10, and the
upper ends of said plates are provided with circular holes through which are passed
trunnions 11 formed on the opposite ends of the block 12 with which the main
suspension cable 13 for raising and lowering the car is connected.
The upper ends of the side plates 8 are adapted to move slightly on the
trunnions 11, and passing centrally through said side plates is a shaft 14, which
is provided at one end with a block shaped head 15, and which is screw threaded at
the opposite end as shown at 16.
The screw threaded end of the shaft 14 projects beyond the adjacent side plate 8,
and is provided with a reduced extension 17, and mounted on the screw threaded

page_text: portion of the shaft 14 is a wheel 18 having an inwardly directed ratchet hub 19, and
the screw thread on the reduced extension 17 of the shaft 14 is the reverse of that
on the shaft, and mounted thereon is a set nut 20, which is intended to hold the
wheel 18 in place, and between the hub 19, and the plate 8 is preferably placed a
washer 21.
The extension 17 of the shaft 14 is also provided with a beveled pinion 22
which operates in connection with a beveled pinion 23 secured to the lower end of a
shaft 24 which passes through a horizontal bracket or support 25 formed on or
secured to the adjacent plate 8, and the upper end of said shaft 24 above said
bracket or support is provided with a sliding collar 26, with which is connected
a lever 27, the outer end of which projects in the direction of the adjacent plate 8,
and is pivotally connected with a vertically movable bar 28, which passes down-
wardly through the bracket or support 25, and the lower end of which is adapted
to operate in connection with the ratchet hub 19 of the wheel 18.
Supported above the bracket or support 25 is a dome shaped cap 29, in which
the upper end of the shaft 24 is pivoted, and said shaft is provided with an ordinary
governor, consisting of the pivoted weighted arms 30, which are connected with the
collar 26 by supplemental pivoted arms 31, and the operation of this device will be
hereinafter described.
Mounted centrally on the shaft 14 and rigidly secured thereto in any desired
manner is a locking disk 32, shown in Figs. 3, 4 and 5, and said locking disk
is provided at each side with a peripheral groove 33 in each of which is pivoted a
plurality of dogs 34 which are preferably four in number, and said dogs on both
sides of said disk project in the same direction, and mounted on said shaft 14 at
cach side of the locking disk 13 is a double pulley 35. These pulleys 35 are exactly
of the same form and construction, and each is provided in its inner face with an
annular space forming an annular chamber in which the locking disk 32 is placed,
and said pulleys 35 are also each provided around said annular space with a
plurality of tangential teeth 36, and these teeth in both of said pulleys project in
the same direction.
The main suspension cable 13 is passed over a pulley 37, supported at the top
of the elevator shaft, and said cable is carried from said pulleys to a drum suitably
located at the bottom of the shaft in the usual manner, said drum being not shown,
this arrangement being similar to that usually employed for raising and lowering
an elevator car.
Mounted at the opposite sides of the support consisting of the plates 8 and other
connected parts are two brackets or supports 38, which are secured to the cross
beam 7, or connected therewith, in any desired manner, and which are preferably
yoke shaped in form, and mounted in each of these supports is a double pulley 39,
one of which is arranged in the same vertical plane as one of the pulleys 35, and
the other in the same vertical plane as the other pulley 35, and I also employ two
cords or cables 40, which are permanently secured to a suitable support at the top
of the elevator shaft, and one of these cords or cables 40 is passed downwardly
to the left and beneath one of the double pulleys 35, and around said pulley, and
then above and around the pulley 39, at the right thereof, and then over and
around said pulley 35, and then over and around the said pulley 39, and down-
wardly through the elevator shaft and preferably through the elevator car and
around the pulley 41, in the bottom of the elevator shaft, and the end thereof
is connected with one end of a lever 42 which is pivoted supported at 43, and the
opposite end of which is provided with a weight 44, and I also provide means
to limit the upward movement of said weight which as shown in the drawing,
consists of a shoulder or projection 45, formed in or on the side wall of the elevator
shaft, but any suitable means may be provided for this purpose.
The other cord 40 after being secured at the top of the elevator shaft as described,
is passed downwardly to the right of and partially around the other pulley 35 and
then over and around the pulley 39 at the left, then over and around said pulley 35,
and then back over and around said pulley 39, and is carried downwardly to the

page_text: bottom of the elevator shaft, where it is passed around a corresponding pulley 41
and connected with a lever 42, as hereinbefore described with reference to the
other cord or cable 40.
By means of this construction, it will be seen that the elevator car, while being
supported by the cable 13 moves on the cords or cables 40, and said cords or cables
pass freely around the pulleys 35 and 39, as the car rises and descends, and the
cords or cables 40 are kept taut by the levers 42, and the lower ends of said cords
or cables are yieldingly supported so as to provide for sudden jerks or jars
occasioned by the starting or stopping of the car in the operation thereof, the lower
ends of said cords or cables being capable of a slight upward movement which
is limited by the stops with which the weights 44 of the levers 42 come in contact,
but in the normal position of these parts, said levers occupy the position shown in
Fig. 1, and the cords or cables 40 are held taut thereby.
In the operation of the car, the pulleys 35 revolve constantly in opposite
directions as the car rises and descends, and one of these pulleys is always locked in
connection with the locking disk 32, by means of the pivoted dogs 34 which operate
in connection with the teeth 36 formed in said pulleys, and one of said pulleys is
locked in connection with said locking disk as the car ascends, and the other as it
descends.
In this operation, the shaft 14 is always revolved in one direction, or to the
right and if at any time the suspending cable of the car should be broken or
disconnected, and the car should start to fall, or if by any reason the car should at
any time be drawn upwardly too fast, the shaft 14 would be turned so quickly that
the governor would be operated by the gear wheels 22 and 23, the pivoted
arms 30 of said governor would be thrown upwardly, and the bar 28 downwardly,
so that the lower end thereof would engage with the ratchet hub 14. This would
prevent the revolution of the wheel 18, with the shaft 14, and said shaft would be
forced through said wheel by reason of its screw threaded connection therewith,
and the hub of said wheel would be pressed upon this adjacent plate 8, and the
separate plates 8 would be drawn together, and by a friction on the pulleys 35,
prevent the revolution thereon, and this would operate as a brake to stop the car.
In the normal operation of the parts, the governor is not revolved with sufficient
rapidity to depress the bar 28, and the brake mechanism does not work, but said
brake governor is instantly thrown into operation, if the suspending cable of the
car should break or be detached therefrom or if for any reason the car should be
drawn upwardly too rapidly.
My improved brake mechanism for elevator cars is simple in construction, and
perfectly adapted to accomplish the result for which it is intended, and it will be
apparent that changes in and modifications of the construction herein described,
may be made without departing from the spirit of my invention, or sacrificing its
advantages.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
1. An elevator car provided with the usual suspending cable by which it is raised
or lowered, and a brake mechanism, comprising two vertical plates secured to the
top of the clevator car, a brake shaft passing therethrough, two double pulleys
mounted on said shaft and adapted to revolve in opposite directions, means for
locking either of said pulleys to said shaft, a governor connected with said shaft,
a threaded wheel mounted on the end of said shaft adjacent to one of said plates,
and provided with a ratchet hub, a locking bar connected with said governor and
operating in connection with said hub, two other double pulleys mounted on
opposite sides of said first named pulleys, and two supplemental cords or cables
which are connected with a suitable support at the top of the shaft, and passed
around the pulleys on the brake shaft, and the pulleys at the opposite sides thereof,

page_text: said supplemental cables being also carried downwardly to the bottom of the shaft
and provided with yielding connections, substantially as shown and described.
2. The combination with an elevator car provided with a cable by which it is
raised and lowered, of a brake mechanism, comprising two supplemental cables
secured at the top of the elevator shaft and provided with suitable connections at
the bottom thereof, a brake shaft mounted in compressible side plates at the top
of the car, two double pulleys mounted thereon, and adapted to revolve in opposite
directions, one of said pulleys being always locked in connection with said shaft,
other pulleys mounted on the opposite sides of the pulleys on the brake shaft, a
screw threaded wheel mounted on one end of said shaft provided with a
ratchet hub, said wheel being adapted to be forced against one of said plates, and
a governor in operative connection with said shaft and provided with a vertically
movable bar which is adapted to operate in connection with said ratchet hub, sub-
stantially as shown and described.
3. In a brake mechanism for elevator cars constructed as hereindescribed, the
combination of two compressible plates, a brake shaft passing therethrough, two
double pulleys mounted on said shaft and adapted to be locked in connection there-
with, one end of said shafts being screw threaded and provided with a screw
threaded wheel which is adapted to be forced against one of said plates, and a
governor geared in connection with said end of said shaft and provided with a
vertically movable locking bar, which is adapted to operate in connection with said
wheel, substantially as shown and described.
4. A brake mechanism for elevator cars constructed as herein described, provided
with supplemental cables which form a part thereof, one end of said cables being
secured at the top of the elevator shaft, and the other end thereof being passed
around pulleys at the bottom of the shaft and connected with pivotally supported
levers, substantially as shown and described.
5. A brake mechanism for elevator cars provided with two compressible plates
secured at the top thereof, a brake shaft passing therethrough, a governor in
operative connection with the end of said shaft, a screw threaded wheel, mounted on
the screw threaded end of said shaft, means connected with said governor for
preventing the revolution of said wheel, two double pulleys mounted on said shaft
and adapted to be locked in connection therewith, and supplemental cords or cables
supported at the top of the elevator shaft and passed around said pulleys, sub-
stantially as shown and described.
6. A brake mechanism for elevator cars provided with two compressible plates
secured at the top thereof, a brake shaft passing therethrough, a governor in
operative connection with the end of said shaft, a screw threaded wheel mounted on
the screw threaded end of said shaft, means connected with said governor for
preventing the revolution of said wheel, two double pulleys mounted on said shaft
and adapted to be locked in connection therewith, and supplemental cords or cables
supported at the top of the elevator shaft and passed around said pulleys, said car
being also provided with supplemental pulleys on the opposite sides of the pulleys
mounted on the brake shaft and around which said supplemental cords or cables
are also passed, substantially as shown and described.
Dated this 24th day of June 1898.
WHEATLEY & MACKENZIE,
40, Chancery Lane, Londonį W.C₁, Agents.