U.S. patent number 3,902,573 [Application Number 05/435,742] was granted by the patent office on 1975-09-02 for elevator control system.
Invention is credited to by Betty Cliff Grove, administratrix, Donald E. Grove, deceased.
United States Patent |
3,902,573 |
Grove, deceased , et
al. |
September 2, 1975 |
Elevator control system
Abstract
An emergency control system is provided for an elevator
installation which responds automatically to a power failure, low
voltage condition, loss of phase, or the like, to move the elevator
to a reference floor, and then to open the elevator doors and hold
them open to permit passengers to leave the elevator. The system of
the invention includes a battery activated source of power which is
maintained charged when the elevator is in its normal operating
condition. In the event of a power failure, the system
automatically switches power from the battery activated source to
appropriate controls in the elevator control system so as to move
the elevator car automatically to a reference floor, and then
automatically to open the elevator doors at the reference floor to
permit the passengers to leave.
Inventors: |
Grove, deceased; Donald E.
(LATE OF Scottsdale, AZ), Grove, administratrix; by Betty
Cliff (Scottsdale, AZ) |
Family
ID: |
23729647 |
Appl.
No.: |
05/435,742 |
Filed: |
January 23, 1974 |
Current U.S.
Class: |
187/290 |
Current CPC
Class: |
B66B
5/027 (20130101) |
Current International
Class: |
B66B
5/02 (20060101); B66B 013/24 () |
Field of
Search: |
;187/29 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Schaefer; Robert K.
Assistant Examiner: Duncanson, Jr.; W. E.
Attorney, Agent or Firm: Jessup & Beecher
Claims
What is claimed is:
1. In an elevator system which includes a car, and circuit means
connected to a main source of electric energy and including a
plurality of individual electrically-operated controls for
controlling up and down movements of the car, and in which said
circuit means includes a further individual control for opening the
doors of the car when the car reaches a reference floor level; an
emergency control system including: an auxiliary power source
including a battery; first relay means coupled to said main source
to be normally energized by electric power derived from said main
source; first contact means controlled by said first relay means
and connected to said auxiliary power source for connecting said
auxiliary power source directly to a first one of said individual
controls in said circuit means upon the de-energization of said
first relay means so as to produce movement of the car to a
reference floor level; second relay means; second contact means
controlled by said first relay means to cause said second relay
means to be energized by said auxiliary power source upon
de-energization of said first relay means; and third contact means
controlled by said second relay means to contact said auxiliary
power source directly to said further individual control in said
circuit means upon the energization of said second relay means to
cause the doors of the car to open when the reference floor level
is reached.
2. The combination defined in claim 1, and including a battery
charging circuit coupled to said main source of electrical energy
and connected to said battery for maintaining said battery in a
charged condition.
3. The combination defined in claim 1, and which includes an
inverter circuit included in said auxiliary power source for
transferring the voltage of said battery to a different value, and
in which said first contact directly connects the output of said
inverter across said first control in said circuit means to produce
movement of said car to a reference floor level.
4. The combination defined in claim 1, and which includes an
emergency light connected in circuit with a second contact means of
said first relay means to be energized upon the de-energization of
said first relay means.
5. The combination defined in claim 1, and which includes fourth
contact means controlled by said second relay means to disconnect
said auxiliary power source from said first individual control in
said circuit means when said second relay means is energized.
6. The combination defined in claim 1, in which said circuit means
includes a level switch positioned to be actuated when the car
reaches said reference floor level; and which includes a second
relay means in circuit with said level switch and with said first
contact means to be energized when said first relay means is
de-energized and when said level switch is actuated, and second
contact means controlled by said second relay means and directly
connected to said first individual control in said circuit means to
stop movement of the car when said second relay means is
energized.
7. The combination defined in claim 6, in which said circuit means
includes electrically-operated door control means, and third
contact means controlled by said second relay means and connected
in circuit with said door control means to cause said door means to
open the doors of the car when said second relay means is
energized.
Description
BACKGROUND OF THE INVENTION
One of the most common problems in the elevator art is that of
electric power failure. When such a power failure occurs in present
day elevator systems, the elevator car comes to an abrupt stop, and
the passengers are held locked in the car. An emergency button
and/or auxiliary telephone within the car are the only present day
means available for notifying those on the outside that an
emergency exists.
Because of the increasing frequency of power blackouts, a real
problem arises, especially within urban areas where elevators are
mandatory for apartment and office buildings, stores, hospitals,
homes for the aged, garages, warehouses, factories, and so on. A
necessity has arisen, therefore, for the development of a
satisfactory emergency power control system which will provide a
supplementary emergency power to move the elevator to a reference
floor, and then to open the elevator doors, in the event of a power
failure, or other malfunction of the normal elevator control
equipment.
The emergency elevator control system of the present invention, in
the embodiment to be described, is advantageous in that it may be
easily installed in conjunction with a present day elevator control
system, and it does not interfere in any way with the safety
features incorporated into the normal control system. The system to
be described provides lighting in the elevator car under the
emergency conditions, and a controlled safe moving of the elevator
car to a reference floor. The emergency control system also
provides means for opening the elevator car and hallway hatch doors
at the reference floor, thereby permitting the passengers to move
safely out of the car and into the hallway. The control may be such
that the emergency lighting in the elevator car remains on after
the elevator and hatch doors have been opened, so as to provide
light in the darkened hallways and corridors of the building.
Specifically, the present invention provides an improved and
relatively simple system which can be incorporated into the
controls of existing elevator systems to provide a simple and
expeditious means for permitting passengers to leave an elevator,
safely and without any appreciable time delay, should a power
failure, or other malfunction occur.
The emergency power system of the invention will be described
herein in conjunction with an hydraulic type of elevator control
system. However, it will become evident as the description proceeds
that the emergency control system of the invention may be used in
conjunction with a wide variety of different types of hydraulically
and electrically controlled elevator systems.
In the hydraulic elevator system to be described, the emergency
control provides for the car to be lowered slowly to the main
floor, or other reference floor, should an emergency condition
occur. This is achieved by controlling the valve which slowly
bleeds the oil in the hydraulic cylinder back to the reservoir, so
that the ram will move slowly downwardly, permitting the elevator
car slowly to descend. The control for the hydraulic system may be
alternating electric current, or direct current, depending upon the
type of electrically operated valves used in the system. In the
embodiment to be described, a direct current control is used,
although it may easily be replaced by an alternating current
control if so required. Direct current voltages may be used to
control the alternating current actuating coils of the various
valves in an alternating current control system by selecting
predetermined direct current "pick" voltages for introduction to
the various alternating current actuating coils.
When the elevator is of the electric type, the control may be such
that the car is either raised or lowered to the next adjacent
floor. This raising or lowering of the car may be determined by the
load in the elevator car, the car being raised when the load is
less than the counterweighting load, and lowered when the load is
greater than the counterweighting load. The control of the
electrically operated elevators is usually coupled to the holding
brake, with the coil of the holding brake being picked to a slip
condition so that the elevator may move up or down to the next
floor, at which point the brake is released and closed. Again the
emergency control system may be either direct current or
alternating current, and it may be used in conjunction with brakes
having direct current actuating coils or alternating current
actuating coils.
The emergency control system of the invention, in the embodiment to
be described, is powered by a reliable, constantly charged direct
current battery source. The emergency control system senses an
emergency condition, and immediately switches to the direct current
battery source. The system protects itself against any off-on
condition, and, as previously noted, it recognizes key safety
circuits incorporated into the usual elevator control system.
When the emergency control system to be described is activated, it
immediately energizes one or more emergency lights in the elevator
car so as to restore illumination within the car. It may also
energize a light in a control panel to illuminate a message
notifying the passengers that the elevator is now under emergency
control. The system to be described then activates an appropriate
control in the elevator control system to cause the elevator car to
be lowered to the main floor at a slow rate of speed, and then to
cause the elevator and hatchway doors to be opened, and to be held
open.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic perspective representation of an hydraulic
elevator installation which may incorporate the emergency control
system of the present invention;
FIG. 2 is a block diagram of the hydraulic elevator control
installation of FIG. 1;
FIG. 3 is a schematic diagram, partly in block form, showing the
controls for the elevator installation of FIGS. 1 and 2, and also
showing an emergency control system embodying the present invention
in one of its aspects;
FIG. 4 is a circuit diagram of an inverter included in the system
of FIG. 3; and
FIG. 5 is a circuit diagram of a battery charger included in the
system of FIG. 3.
DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT
In the representation of FIG. 1, an elevator car 10 is supported on
guard rails 12 in a vertical elevator well, or pit. The car is
moved up and down in the well by means of an hydraulic ram 16 which
extends into an hydraulic cylinder or casing 18. Spring buffers 20
are provided at the bottom of the well. A cross head safety switch
22 is mounted on the top of the car 10, and it is operated when the
car moves to its upper limit of travel. A pit safety switch 24 is
mounted near the bottom of the well, and it is operated when the
car is at its lower limit of travel. These safety switches assure
that the car 10, under no conditions, will be driven beyond its
upper or lower limits. A door safety switch 30 is mounted on the
car 10, and this switch is operated when the doors of the car are
open to prevent movement of the car until the doors are closed. The
elevator is controlled by a power unit and hydraulic controller
32.
The representation of FIG. 2 illustrates the manner in which the
elevator hydraulic control system 32 controls the ram 16 by pumping
hydraulic fluid into the casing 18 to raise the car 10, and by
subsequently bleeding the hydraulic fluid from the casing to lower
the car. The hydraulic fluid is pumped from an oil reservoir 40 in
the controller 32 by means of a pump 42 which is driven by an
electric motor 44. The oil is pumped through a valve 46, and
appropriate control of the valve 46 causes the fluid to be bled
back to the reservoir 40 for the controlled descent of the car 10.
The motor 44 and valve 46 are controlled by a normal elevator
control system represented by the block 48. Three-phase alternating
current power is supplied to the motor 44 through the control
system 48. The emergency control system of the invention is
represented by the block 50, and one embodiment of the emergency
control system is shown in more detail in the diagram of FIG. 3. A
portion of the conventional control system of a typical
hydraulically controlled elevator, such as the installation of
FIGS. 1 and 2, is also shown in FIG. 3.
The three-phase power line is connected through usual breaker
contacts 100 to the pump motor 44. A transformer T1 is connected
across one of the phases of the three-phase AC power line, and the
transformer develops 115 volts, for example, across its secondary.
The secondary of the transformer is connected through the
normally-closed pit safety switch 24 and cross head safety switch
22 and emergency switch 50 to a lead 52, and the secondary is
directly connected to a lead 54. The various operating controls for
the elevator are connected between the leads 52 and 54.
For example, the junction of the switches 22 and 50 is connected to
a pair of down relay contacts DO, and to a pair of level-down relay
contacts LD. The DO relay contacts are connected to a pair of
down-auxiliary relay contacts DX which, in turn, are connected to
the energizing coil of a down pilot relay E, whose other terminal
is connected to the lead 54. The relay contacts DX and LD are also
connected through a pair of normally-closed relay contacts A3 to
the actuating coil of the down-slow valve 46a, the other terminal
of which is connected to the lead 54. These contacts are also
connected through a pair of relay contacts HSI to the actuating
coil of the down-fast valve 46b which, in turn, is also connected
to the lead 54.
The lead 52 is also connected through a pair of normallyclosed
relay contacts A3 to the movable arm of a second cross head switch
22a which operates in addition to the cross head safety switch 22.
The normally-open contact of the cross head section 22a is
connected back to the lead 52, and a normally-closed contact is
connected to a normally-closed pit safety switch 24a which operates
in addition to the pit safety switch 24.
The cross head switch 22a includes a second movable arm which is
connected through a first floor-level switch 56 to an emergency
light 58; and which is also connected through a pair of hatch door
contacts 60 to the door-open relay DO, to a car-door relay OR, and
to a pair of normally-open relay contacts A1. The relay DO is also
connected through a pair of up-holding relay contacts UA1 to the
coil of an up-auxiliary relay UX. The aforesaid relay coils are all
connected to the lead 54.
The lead 52 is also connected through a pair of normally-closed
relay contacts A3, and through a door-open limit switch DOL to an
open-door relay OD and to an open-limit relay OU. The relay OU is
connected to the lead 54, and the relay OD is connected through a
pair of a safety edge contacts SE to the lead 54.
The emergency system of the invention includes an alternating
current power-sensing relay A1 which is normally energized, but
becomes de-energized upon a loss of power, loss of voltage, or any
other malfunction which affects the secondary voltage of the
transformer T1. A battery-actuation relay A2 is connected in shunt
with the relay A1, both the relays A1 and A2 being connected across
the secondary of the transformer T1.
A phase-loss sensing relay PS is connected across the primary of
the transformer T1 and across the other two phases of the
three-phase AC power line. Relay PS is normally energized, but
becomes de-energized upon a loss of phase.
A battery charger 62 is also connected across the secondary of the
transformer T1. The circuitry of the battery charger will be
discussed in conjunction with FIG. 5. A storage battery 64 is
connected across the battery charger 62, and an inverter 66 is
connected across the storage battery. The circuit details of the
inverter 66 will be discussed in detail in conjunction with FIG.
4.
The positive terminal of the battery charger 62 and storage battery
64 is grounded, and is connected through a pair of normally-open
relay contacts A2 to a pit-and-cab interlock relay B, a levelling
relay AX, and a battery-transfer coil A3. The relay B is connected
through a pair of normally-open relay contacts A3 to the pit switch
24a; the relay AX is connected through a pair of normally-open
relay contacts A1 to the cross head switch 22a; and the battery
transfer relay A3 is connected through a pair of normally-open
contacts A1 to the level switch 56. The other terminals of the
relays B, AX and A3 are connected through a pair of normally-open
relay contacts A1 to the emergency light 58.
The negative output lead of the inverter 66 is connected through a
pair of normally-closed relay contacts AX, and through a pair of
normally-open relay contacts B and a pair of normally-open relay
contacts A3, to the down-slow valve 46a. The positive terminal of
the inverter 66 is connected to the lead 54.
The relays AX, B and A3 in the emergency control system shown in
FIG. 3 are 24-volt direct current relays, and the battery 64 is a
24-volt battery. The inverter 66 in the illustrated embodiment
produces a direct current output voltage of 48-volts direct
current, which is sufficient to operate the actuating coil of the
down-slow valve 46a and the relay coil DO, although these elements
are designed for normal operation in the particular control system
on 115-volts alternating current.
During normal operation of the elevator control system, both the
relays A1 and A2 are energized, and the A1 contacts, shown closed
in FIG. 3, are open, as are the A2 contacts shown closed in FIG. 3.
Under these conditions the elevator is under the control of its
normal control circuitry to move up to selected floors and down to
selected floors.
The car 10 is caused to move upwardly by closing the breaker
contacts 100 to energize the pump motor 44. The car is subsequently
caused to move downwardly by energizing a relay HS1, which closes
the HS1 contacts to open the down-fast valve 46b. When the car
approaches a pre-selected floor, the down-level switch LD closes,
and this causes the down-fast valve 46b to close and the down-slow
valve 46a to open. Then, when the selected floor is reached, the
switch LD opens to cause the down-slow valve 46a to close, and the
car stops.
The various other controls shown in FIG. 3, apart from the
emergency control system, are standard and need not be described in
detail.
In the event of a power failure, the relays A1 and A2 becomes
de-energized and all their normally-closed relay contacts assume
the closed position shown in FIG. 3. Under these conditions the
emergency light 58 is immediately illuminated. Also, the battery
transfer relay A3 is now connected across the storage battery 64 by
the closure of the relay contacts A2, and relay A3 becomes
energized. The pit and cab interlock relay B is also energized by
the closing of the relay contacts A3, so long as the pit switch 24a
and, the cross head switch 22a, and the car door contacts 61 are
all closed. Now, the down-slow valve 46a is connected across the
inverter 66, and it opens to permit the car to descend slowly.
The descent continues until the first floor, or other reference
floor, is reached, and the level switch 56 is closed. When the
level switch 56 closes, the levelling relay AX becomes energized to
break the connection to the down-slow valve A3, so that the car
stops. The levelling relay AX also completes a circuit to the relay
OD at this time so that the car and hatch doors are opened to
permit the occupants of the car to escape. The switch DOL is a
door-open limit switch, and it is closed when the doors are closed,
as is the door edge safety switch SE.
The inverter 66, as shown in FIG. 4 may be a usual prior art solid
state system. The illustrated inverter is capable of providing
different output direct current voltages, and, in the illustrated
embodiment, a 48-volt output voltage is used. The inverter is
activated by the storage battery 64 which introduces a 24-volt
direct current voltage across the input terminals 100.
The battery charger 62 is shown in circuit detail in FIG. 4, and it
also may be a conventional solid state type of battery charger. The
charger includes an integrated circuit of the type designated
MC1723CG, as shown, and also incorporates a solid state full-wave
rectifier designated MDA920-1 which is connected across the
secondary of a transformer T4. The 115-volt alternating current
input voltage from the transformer T1 of FIG. 3 is applied across
the input terminals 200 of the circuit, and the 24-volt direct
current charging voltage is developed across the output terminals
202.
The invention provides, therefore, an improved emergency control
for an elevator which, in the event of power failure, asserts a
secondary control on the elevator control system so as to move the
car to a reference floor, and then to open the doors of the car to
permit the occupants to escape.
It will be appreciated that although a particular embodiment of the
invention has been shown and described, modifications may be made.
It is intended in the following claims to cover the modification
which come within the true spirit and scope of the invention.
* * * * *