TECHNICAL FIELD
[0001] This invention relates to a safety device for working on top of an elevator car,
which is employed in an elevator in which a driving machine is disposed at an upper
portion of a hoistway, and which prevents a worker from colliding against the driving
machine while working on top of the car.
BACKGROUND ART
[0002] Fig. 13 is a side view showing a conventional elevator such as disclosed, for example,
in
EP0926093A, and Fig. 14 is a plan view showing the elevator in Fig. 13. In the figures, a driving
machine 2 having a sheave 3 is fixed to an upper portion of a hoistway 1. A middle
portion of a main rope 4 is wound around the sheave 3.
[0003] A car 5 and a counterweight 6 are suspended by the main rope 4. A pair of car suspending
sheaves 7 around which the main rope 4 is wound are provided at a bottom portion of
the car 5. A counterweight suspending sheave 8 around which the main rope 4 is wound
is provided at a top portion of the counterweight 6. The car 5 is provided with car
doors 9. Landing doors 10 opposing the car doors 9 are provided on a hall side.
[0004] A door machine 11 for opening/closing the car doors 9 and the landing doors 10 is
mounted on a top portion of the car 5. Also, a fence 12 for restricting the area of
movement for a worker while working on top of the car 5 is erected on the top portion
of the car 5.
[0005] In such an elevator, as shown in Fig. 14, a portion of the driving machine 2 is disposed
in an area where the car 5 is projected in its raising and lowering direction. In
other words, a portion of the driving machine 2 overlaps the car 5 when looked at
from above. Accordingly, a fear exists that a worker may run into the driving machine
2 while working on top of the car 5. To prevent this, the worker is kept from entering
an area S1 directly below the driving machine 2 by providing the fence 12.
[0006] Further, since a space S3 is secured above an area S2 on the car 5 where the worker
can move, the worker can safely carry out his work while standing even if the car
5 moves to an uppermost position.
[0007] However, since various devices other than the door machine 11 are disposed on top
of the car 5, and because it is difficult to actually provide the fence 12, the fear
exists that the work space will become very small if the fence 12 is provided.
[0008] Next, Fig. 15 is a side view showing a conventional elevator such as disclosed, for
example, in Japanese Utility Model Publication No.
48-3961, and Fig. 16 is a plan view showing the elevator in Fig. 15. In the figures, a ceiling
detection plate 14 is suspended from a ceiling portion of the hoistway 1 through a
plurality of hangers 13.
[0009] In such an elevator, when the worker works on top of the car 5, if the car 5 is raised
and the worker contacts the ceiling detection plate 14, it is detected by a sensor
(not shown), to thereby stop the raising of the car 5. Accordingly, the worker is
prevented from colliding against the driving machine 2.
[0010] However, since the ceiling detection plate 14 spreads above the whole car 5, the
area S3 can not be used for maintenance space, and there is problem that maintenance
work on the driving machine 2 can not be performed from the top of the car 5. Further,
it is necessary to heighten the ceiling of the hoistway 1 to permit the worker to
stand on the car 5 when the car 5 moves to the uppermost floor, thereby inhibiting
effective utilization of space in the building.
[0011] Next, Fig. 17 is a side view showing a conventional elevator such as disclosed, for
example, in Japanese Patent No.
2862713, and Fig. 18 is a plan view showing the elevator in Fig. 17. In the figures, a plurality
of chains 15 are suspended from the driving machine 2.
[0012] In such an elevator, the worker contacts or sees the chains 15 before colliding against
the driving machine 2, to thereby prevent collision with the driving machine 2.
[0013] However, since there is a possibility that the worker will not contact or recognize
the chains 15 because of their position and the position of the worker on the car
5, safety can not be sufficiently secured.
DISCLOSURE OF THE INVENTION
[0014] The present invention is made to solve the problems mentioned above, and an object
of the present invention is to provide a safety device for working on top of an elevator
car, wherein a working space on a car can be secured, maintenance on a driving machine
can be performed from the top of the car, and workers can be more safely kept from
running into the driving machine.
[0015] To this end, according to one aspect, there is provided a safety device for working
on top of an elevator car, employed in an elevator in which a driving machine for
raising and lowering a car is disposed at an upper portion in a hoistway and a portion
of the driving machine is disposed in an area where the car is projected in its raising
and lowering direction, comprising: a detection plate suspended in the hoistway and
disposed between the driving machine and the car to allow maintenance operations from
a top of the car, the detection plate being capable of moving upwardly by being pushed
from a lower position; a buffer attached to a bottom surface of the detection plate;
a plurality of detecting switches for detecting the upward movement of the detection
plate; and a stop circuit for stopping the raising of the car when at least one of
the detecting switches is operated by the upward movement of the detection plate.
[0016] According to the present invention, there is provided a safety device for working
on top of an elevator car, employed in an elevator in which a driving machine for
raising and lowering a car is disposed at an upper portion of a hoistway and a portion
of the driving machine is disposed in an area where the car is projected in its raising
and lowering direction, comprising: a light projecting device provided on a side wall
of the hoistway for horizontally projecting a plurality of light beams below the driving
machine; a light receiving device provided on a side wall of the hoistway opposite
to the light projecting device for receiving the light beams projected from the light
projecting device; and a stop circuit for stopping the raising of the car when at
least one of the light beams is intercepted.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017]
Fig. 1 is a side view showing an elevator according to a first embodiment for a better
understanding but not being part of the claimed invention;
Fig. 2 is a plan view showing the elevator in Fig. 1;
Fig. 3 is a cross-sectional view showing an essential portion of the safety device
in Fig. 1;
Fig. 4 is a cross-sectional view showing a state where the air bag in Fig. 3 is pushed
from the lower position;
Fig. 5 is a circuit diagram showing a control circuit of the safety device in Fig.
1;
Fig. 6 is a plan view showing a safety device for working on top of an elevator car
according to a second embodiment for a better understanding but not being part of
the claimed invention;
Fig. 7 is a side view showing the safety device in Fig. 6;
Fig. 8 is a side view showing an elevator according to an embodiment of the present
invention;
Fig. 9 is a plan view showing the elevator in Fig. 8;
Fig. 10 is a circuit diagram showing the control circuit of the safety device in Fig.
8;
Fig. 11 is an explanatory view showing a state where the worker goes into the region
between the light emitting device and the light receiving device in Fig. 8;
Fig. 12 is a plan view showing the safety device in Fig. 11;
Fig. 13 is a side view showing an example of a conventional elevator;
Fig. 14 is a plan view showing the elevator in Fig. 13;
Fig. 15 is a side view showing another example of a conventional elevator;
Fig. 16 is a plan view showing the elevator in Fig. 15;
Fig. 17 is a side view showing another example of a conventional elevator; and
Fig. 18 is a plan view showing the elevator in Fig. 17.
BEST MODE FOR CARRYING OUT THE INVENTION
[0018] A preferred embodiment of the present invention will be described below with reference
to the accompanying drawings.
[0019] Fig. 1 is a side view showing an elevator according to a first embodiment for a better
understanding but not being part of the claimed invention, and Fig. 2 is a plan view
showing the elevator in Fig. 1. In the figures, a driving machine 21 is fixed to an
upper portion of a hoistway 1. The driving machine 21 has a motor 22, a sheave 23
rotated by the motor 22, reduction gears 24 for transmitting the driving force of
the motor 22 to the sheave 23, and a braking portion 25 for braking the rotation of
the sheave 23.
[0020] A middle portion of a main rope 4 is wound around the sheave 23. A car 5 and a counterweight
6 are suspended by the main rope 4. A pair of car suspending sheaves 7 around which
the main rope 4 is wound are provided at a lower portion of the car 5. A counterweight
suspending sheave 8 around which the main rope 4 is wound is provided at a top portion
of the counterweight 6.
[0021] The car 5 is provided with car doors 9. Landing doors 10 opposing the car doors 9
are provided on a hall side. A door machine 11 for opening/closing the car doors 9
and the landing doors 10 is mounted on a top portion of the car 5.
[0022] A safety device 31 for working on top of the car 5 for preventing workers on the
car 5 from running into the driving machine 21 is suspended from a ceiling portion
of the hoistway 1. The safety device 31 is disposed at a position between the car
5 and the driving machine 21 where it does not interfere with the car 5.
[0023] Further, the safety device 31 has a plurality of (four in the figure) hangers 32,
a detection plate 33 suspended by the hangers 32, a plurality of detecting switches
34 disposed between the hangers 32 and the detection plate 33, and an air bag 35 attached
as a buffer to a bottom portion of the detection plate 33.
[0024] Fig. 3 is a cross-sectional view showing an essential portion of the safety device
31 in Fig. 1. The detection plate 33 is provided with a plurality of penetrating holes
33a. Each detecting switch 34 has a first contact seat 36 made of insulating material
and connected to a lower end portion of the hanger 32, a second contact seat 37 made
of insulating material and fixed to the detection plate 33, a first contact 38 fixed
to the first contact seat 36, and a second contact 39 fixed to the second contact
seat 37 and contacting with and separating from the first contact 38.
[0025] The second contact seat 37 and the second contact 39 are provided with penetrating
holes 37a and 39a continued to the penetrating hole 33a. The first contact seat 36
has a flange portion 36a for supporting the first contact 38, and a rod portion 36b
penetrating the penetrating holes 33a, 37a and 39a.
[0026] Fig. 4 is a cross-sectional view showing a state where the air bag 35 in Fig. 3 is
pushed from the lower position. In the case where the air bag 35 is pushed from the
lower position, the air bag 35 is deformed and the detection plate 33 is pushed upwardly.
Accordingly, the second contact seat 37 and the second contact 39 fixed to the detection
plate 33 are moved upwardly to separate the second contact 39 from the first contact
38.
[0027] Fig. 5 is a circuit diagram showing a control circuit of the safety device 31 in
Fig. 1. Contacts 34A to 34D of four detecting switches 34 are connected in series
with each other. Since the contacts 34A to 34D are normally-closed contacts, when
any one of the contacts 34A to 34D is opened, the raising of the car 5 is stopped
by a stopping circuit 40.
[0028] In the above described elevator, during work on the car 5, when the car 5 is raised
with a worker in the area S1 directly below the driving machine 21, the worker collides
with the air bag 35, and the detection plate 33 is pushed upwardly. Consequently,
the detecting switches 34 are opened, and the raising of the car 5 is stopped.
[0029] Accordingly, the workers can be more safely prevented from colliding against the
driving machine 21. Also, the working area S2 on the car 5 can be sufficiently secured,
and maintenance for the driving machine 21 can be performed from the top of the car
5. Further, since the air bag 35 is used, the impact of collision against the safety
device 21 can be sufficiently decreased, thereby further improving safety. Also, since
a plurality of detecting switches 34 are provided and the raising of the car 5 is
stopped when any one of the detecting switches 34 is operated, reliability can be
improved.
[0030] It should be noted that, while the air bag 35 is shown as the buffer in the first
embodiment, the buffer is not limited to this, and it is also possible to use, for
example, sponge, foamed plastic or the like.
Second Embodiment
[0031] Next, Fig. 6 is a plan view showing a safety device for working on top of an elevator
car according to a second embodiment for a better understanding but not being part
of the claimed invention, and Fig. 7 is a side view showing the safety device in Fig.
6. In this embodiment, an oil receiving portion 41a shaped like a tray is provided
at a top surface of the detection plate 41. The other constructions are the same as
in the first embodiment.
[0032] In such a safety device, any lubricating oil leaking from the reduction gears 24,
bearings (not shown) or the like of the driving machine 21 is received by the oil
receiving portion 41a. Accordingly, the lubricating oil is prevented from dropping
onto the car 5.
Third Embodiment
[0033] Next, Fig. 8 is a side view showing an elevator according to the present invention,
and Fig. 9 is a plan view showing the elevator in Fig. 8. In this embodiment, a photoelectric
proximity detecting device having a light projecting device 51 and a light receiving
device 52 is used as a safety device. The light projecting device 51 and the light
receiving device 52 are provided on the side walls of the hoistway 1 to oppose each
other. A plurality of light beams 53 projected from the light projecting device 51
travel horizontally below the driving machine 21 and are received by the light receiving
device 52. In other words, the light projecting device 51 and the light receiving
device 52 are disposed at positions lower than the driving machine 21. The construction
of the rest of the elevator is the same as in the first embodiment.
[0034] Fig. 10 is a circuit diagram showing the control circuit of the safety device in
Fig. 8. An output contact 54 of the photoelectric proximity detecting device is connected
to the stopping circuit 40 for stopping the raising of the car 5.
[0035] In such an elevator, during work on the car 5, when the car 5 is raised with a worker
in the area S1 directly below the driving machine 21, the worker becomes positioned
between the light projecting device 51 and the light receiving device 52, as shown
in Fig. 11, before colliding against the driving machine 21. At this time, as shown
in Fig. 12, one portion of the plurality of light beams 53 is intercepted by the worker.
When the light beams 53 are intercepted, this is detected by the light receiving device
52, and the output contact 54 is opened, to thereby stop the raising of the car 5.
[0036] Accordingly, the workers can be more safely prevented from colliding against the
driving machine 21. Also, the working area S2 on the car 5 can be sufficiently secured,
and maintenance for the driving machine 21 can be performed from the top of the car
5. Further, since the worker only intercepts the light beams 53, the worker receives
no impact from a collision. In addition, since the plurality of detecting light beams
53 is projected and the raising of the car 5 is stopped when any portion of the light
beams 53 is intercepted, reliability can be improved.