Automatic Safety Devices for Elevators or Lifts.
Year: 1899

page_text: Date of Application, 14th Nov., 1899-Accepted, 20th Jan,, 1900
Automatic Safety Devices for Elevators or Lifts.
We, URDAN SYLVESTER ALZ, Collector, and HENRY STANISLAUS NAGENGAST,
Gentleman, both of Gardenville, County of Baltimore and State of Maryland,
United States of America, 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 an automatic safety device for elevators or lifts to
arrest or stop the car should it accidentally fall.
The object of the invention is to provide a simple device employing compressed
air which may be applied to elevators and which will be automatic in its
operation.
In order to make the invention clearly understood, we have shown in the
accompanying drawings means for carrying the same into practical effect,
without, however, intending to limit the invention to this particular construction,
as the same may be embodied in other forms.
Figure 1 is a vertical section through an elevator-car with the improved stop
device attached and also shows the stationary car-guides and inclined safety-ways.
Figure 2 is a horizontal section on the line 2-2 of Fig. 1.
Figure 3 is a vertical section on the line 3-3 of Fig. 2.
Figure 4 is a section view on a larger scale, showing the vent-valve carried on
the car.
Figure 5 is a perspective view showing the cylinders and the pipe connections
therewith.
In the drawings, A designates the elevator-car, movable up and down on
stationary vertical guides, bb, preferably one at each corner of the elevator-
shaft. A frame, C, is secured to the car, preferably at the bottom, and said
frame is provided in the present instance with two compartmenia, d, and e, one
above the other, and a horizontal guide space or slot, f, is formed between the
said two compartments by plates ff. The upper compartment, d, in the present
instance contains two air-cylinders, d, and, located at one end of
the compartment, and the lower compartment, e, is also provided with two air-
cylinders, e and, e, located at the opposite end. The air-cylinders have hori-
zontal position, and each is provided with a piston, g, having a stem, g', which
moves loosely through the head of the cylinder the fit of the stem through the
hend being such as to allow the free inlet and outlet of air at that end of the
cylinder whenever the piston moves. Two cross-bars, h, and, i, are horizontally
movable in the space or slot f, and extend from one side to the other of the
f. The sliding
frame, C, and said bars at each end carry a pivoted guide-block in the upper
cross-bar, h, has two studs, k, which project up through slots,
plate f, and are secured to the piston-stems of the upper cylinders, d, and
the sliding har h, moves with the pistons. The other sliding cross-bar, i, also has
C017

page_text: two studs, , which, however, project down through slots in the lower plate, f,
and are secured to the piston-slems of the lower cylinders, e', e, and this bar, i,
moves with said pistons.
The elevator-shaft through which the car travels is provided at opposite sides
with inclined safety-ways, n, m, the lower ends of which are close together and
which gradually diverge or spread apart as they extend up. It will be under-
stood, of course, that the inclination of the ways, m, m³, as shown in the drawings,
is exaggerated in order to make the feature clear. As here shown, the inclined
ways, m, m', are grooved.
The pivoted guide-blocks, j, have position in the grooves of the inclined
ways, m, m', and it will be seen that as the car moves up the guide-blocks, j, and
their attached parts will move forward-that is, away from their respective
cylinders and the piston, g, will thereby be drawn toward the cylinder-heads,
and the downward movement of the car will cause the said guide-blocks to move
in the reverse direction.
The upper air-cylinders, d, and, are provided with an air-pipe, n, which
opens in the end of the cylinder opposite the end having the piston-stem, and
said pipe, n, connects with the pipe, ¹. The lower cylinders, e, and, e, are also
provided with air-pipes o, arranged like the first-named pipes, which connect
with the pipe, o. The pipes, o¹, and, n¹, are connected, and thereby form a com-
plete connection between all the cylinders.
The guide-blocks j, and pistons, g, conet with the inclined guides in such
manner that when the car is moving downward the pistons will compress the air
that may be in the cylinders, and the resistance of this compressed air will
gradually arrest the movement of the pistons and guide-blocks, and the car will
consequently be gradually stopped. The invention therefore is operative without
the employment of a pump: but in the present instance we have shown an air-
compressing pump, P. as a mere supplemental device.
In the present instance the vertical car-guide, 61, has a rack 7, and a pinion, r,
which is suitably mounted on the top of the car, A, meshes with this rack. The
pinion or the shaft on which it is mounted carries a crank. a. Au air-com-
pressing pump, P, secured to the top of the car, has a piston and stem of ordinary
construction, and a pitman, t, connects the piston-stem with the said crank, s.
An air-pipe, u, connects the air-pump with the pipe, n¹, communicating with
the cylinders under the car, and a valve, e, located in the car controls the escape
of compressed air from the cylinders and the pump.
The controlling-valve is shown in section in Fig. 4 and is to be operated by
hand; but it is obvious that it might be operated by the foot, and the construction
may be varied from that shown. In the present instance the valve consists of a
cylinder having a piston, ir, and a stem projects from the piston and has a
presser-knob, . The interior of the cylinder is provided with a groove r, and
stop-lugs, y, y, limit the movement of said piston.
It will be seen that when the piston, r, is pushed down the compressed air will
escape around the piston through the groove, r, and air from the cylinders will
thereby be released.
The object of employing the pump, P, is to aid in the compression of air in the
cylinders, to the pistons of which the slide-bars and guide-blocks, j, are connected.
It is to be understood that the pump is intended to compress air in the cylinders
both when the car is ascending and descending.
The operation of the device is as follows: Suppose the car to be at the bottom
of the shaft and the guide-blocks, j. in the grooves of the inclined ways, m, m².
As the car moves upward the guide-blocks, j, will follow the grooves, m, m³, and
the pistons in all the cylinders being connected to the guide-blocks will gradually
move outward or make their full stroke toward the cylinder-heads. At the same
time the pump P, by means of the rack, pinion, and pitman, will be forcing
air through the pipe, w, to pipes, n¹, and o¹, and thereby charging the cylinders
behind the pistons with compressed air. The pump, P, should be so proportioned

page_text: with respect to the size of the air-cylinders that said cylinders will become filled
with compresed air when the car has reached the top of the shaft. Thus it will
be seen that when the elevator is going up the cylinders will all become charged
with compressed air.
In order for the car to descend, air must be discharged from behind tho
pistons g, in order that the guide-blocks may gradually move toward the center
vertical line, and to effect the proper discharge of the air the valve, r, has been
placed in the pipe, u, within easy reach of the person who has charge of the car.
By means of this valve, r, the operator discharges air from the pipe, u, which
reduces the air-pressure acting on the pistons in the cylinders, and upon such
reduction of air-pressure the pistons and guide-blocks will move inward and the
elevator will descend, but only as fast as the escaping air will permit. By this
construction it will be seen that in order to descend the pressure behind the
pistons, g, must be released to permit the guide-blocks, j, to move toward each
other, and the discharge-groove, r, in the valve can be made larger or smaller,
so the discharge of compressed air may be more or less rapid. It will thus bo
seen that if the cable supporting an elevator-car should break the compressed air
not being able to escape from the cylinders would arrest the movement of the
pistons and the sliding bars, h, i, and the guide-blocks, j, would be held
stationary in the grooves of the inclined ways, m, m', and the elevator thereby
stopped. The elevator-car having stopped would remain stationary until air was
discharged at the valve, 1.
While we have shown and described a pump to be used in connection with the
cylinders, it is obvious that the pump may be dispensed with and reliance placed
on the atmospheric air in the cylinders and pipes.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:
1. In an automatic safety device for elevators the combination of an elevator-
car movable up and down; inclined guides or ways at opposite sides of the
elevator-shaft; guide-blocks carried by the car and coacting with the inclined
guides or ways: an air-cylinder provided with a piston and a stem and carried
on the car and said pistons coacting with the guide-blocks so that normally at all
times when the car is descending the air in the cylinder will be resisting and a
valve on the car to control the escape of air from the air-cylinder during the
ordinary descent of the car, for the purpose set forth.
2. In an automatic safety device for elevators the combination of an elevator-
car movable up and down; stationary inclined guides or ways; air-cylinders each
having a piston and stem and carried on the car; means on the car coacting
with the inclined guides or ways: an air-pump carried by the car and provided
with means for establishing communication with the air-cylinders; and a valve
on the car to control the escape of air from the cylinder to permit the car to
descend, for the purpose set forth.
3. In an automatic safety device for elevators the combination of an elevator-
car movable up and down; stationary inclined guides or ways at opposite sides of
the elevator-shaft; air-cylinders mounted beneath the car one in a plane higher
than the other, and each having a piston and stem; horizontal plates, f', f³,
forming a slot or space between the higher and lower cylinders; cross-hars
movable in said slot or space and connected with the piston stems and guide-
blocks mounted on the cross-bars and coacting with the said inclined guides,
for the purpose set forth.
4. In an automatic safety device for elevators the combination of an elevator-
car movable up and down; stationary inclined guides or ways closer together at
the bottom than at the top: one or more air-cylinders, each having a piston and
stem: an air-pump carried by the car to charge the said cylinders with air:

page_text: guide-blocks on the car which coact with the pistons and the inclined guides or
ways; and a valve on the car to control the escape of air from the cylinders for
the purpose set forth.
Dated this 24th day of October 1899.
Witnesses
-
CHARLES B. MANN,
CHARLES VIETSCH.
URBAN SYLVESTER ALZ.
HENRY STANISLAUS NAGENGAST,