1. An elevator comprising: a traction machine (3); an 5 elevator car (5); a counterweight (10); a plurality of main ropes (4) wound around the traction machine (3) and suspending the elevator car (5) and the counterweight (10); and a weighing device (8) provided at end portions of the main ropes (4) on a side of the elevator car (5), the 10 weighing device (8) comprising a main rope receiver portion (16) that supports the end portions of the plurality of main ropes (4), and a main rope receiver supporting portion (17) that supports the main rope receiver portion (16) and changes its deflection amount due to a load applied to the 15 end portions of the main ropes (4), characterized in that wherein the weighing device (8) is provided with an arm (19) that changes its inclination by displacement of the main rope receiver portion (16), and an angle detector (20) that detects an angle of the arm (19). 20

2. The elevator as claimed in claim 1, wherein the arm (19) of the weighing device (8) changes its inclination in a vertical direction of a hoistway (1). 25 3. The elevator as claimed in claim 2, wherein the 13 weighing device (8) includes a main rope receiver guiding portion (18) that restricts horizontal displacement of the main rope receiver portion (16), and the arm (19) takes the main rope receiver guiding portion (18) as a fulcrum. 5

4. The elevator as claimed in claim 2, wherein the arm (19) takes a portion other than the weighing device (8) as a fulcrum. 10 5. The elevator as claimed in claim 4, wherein the arm (19) takes, as a fulcrum, a support member (22) which is fixed on a floor surface or a machine beam (9) on which the weighing device (8) is installed. 15 6. The elevator as claimed in claim 2, wherein the end portions of the plurality of main ropes (4) on the side of the elevator car (5) includes a tension adjusting portion (21) that adjusts tension of each of the plurality of main ropes (4). 20

7. The elevator as claimed in any one of claims 1 to 6, wherein the elevator includes a control device (15) and a position detection device for the elevator car (5), the control device (15) calculating a load weight within the 25 elevator car (5) from information on a load exerted on the 14 end portions of the plurality of main ropes (4) which is detected from an output of the angle detector (20) of the weighing device, and position information of the elevator car (5) which is detected from the position detection 5 device.

[Technical Field]
The present invention relates to a weighing device of
5 an elevator.
[Background Art]
In general, a weighing device which is arranged at
end portions of main ropes and in which the main ropes are
10 arranged on a main rope receiving plate supported by an
elastic member, supports a weight of an elevator car and a
load weight within the elevator car which are transmitted
by the plate via the main ropes. At this time, an amount
of deflection produced in the elastic member supporting the
15 plate will be changed by a change in the load weight within
the elevator car, and a change in the position of the plate
will occur, so that the change in the load weight within
the elevator car is detected with detection of a
displacement amount of the plate by a detector.
20
[Summary of Invention]
[Technical Problem]
In International Patent Publication WO 2004/089802, a
weighing device which performs load detection at main rope
25 end portions is described. However, in this system,
2
adjustment of an initial position is required to be
performed in such a manner that a detection plate displaces
within a detection range of a displacement detector, and
there is a problem that periodical position checking and
5 adjusting work of the detection plate will be required.
[Solution to Problem]
As a structure for addressing the above-mentioned
problem, an elevator is proposed that comprises a traction
10 machine, an elevator car, a counterweight, a plurality of
main ropes wound around the traction machine and suspending
the elevator car and the counterweight, and a weighing
device provided at end portions of the main ropes on a side
of the car, the weighing device comprising a main rope
15 receiver portion that supports the end portions of the
plurality of main ropes, and a main rope receiver
supporting portion that supports the main rope receiver
portion and changes its deflection amount due to a load
applied to the end portions of the main ropes,
20 characterized in that wherein the weighing device comprises
an arm that changes its inclination by displacement of the
main rope receiver portion, and an angle detector that
detects an angle of the arm.
25 [Advantageous Effects of the Invention]
3
The angle detector does not require provision of a
detection target such as a detection plate or the like at
the time of detection. Therefore, it is possible to
simplify adjustment of an initial position and periodical
5 position checking and adjusting work of the weighing device
which performs the load detection at the end portions of
the main ropes.
[Brief Description of Drawings]
10 Fig. 1 is a structure view showing an elevator
according to Embodiment 1 of the present invention.
Fig. 2 is a view showing a weighing device of Fig. 1.
Fig. 3 is a view showing operation of the weighting
device of Fig. 2.
15 Fig. 4 is a view showing end portions of main ropes
to which the weighing device of Fig. 1 is not installed.
Fig. 5 is a view showing a structure of a weighing
device according to Embodiment 2 of the present invention.
20 [Description of Embodiments]
Embodiments of the present invention will be
explained hereinafter with reference to the drawings.
Embodiment 1
25 Fig. 1 is a view showing a structure of an elevator
4
according to Embodiment 1 of the present invention. In Fig.
1, there is illustrated a hoistway 1 of the elevator and a
machine room 2 is provided at an upper portion of the
hoistway 1. In the machine room 2, a traction machine 3 is
5 installed and includes a sheave. Around the sheave of the
traction machine 3, a plurality of main ropes 4 are wound.
An elevator car 5 is suspended within the hoistway 1
on one sides of the main ropes 4 wound around the sheave,
and goes up and down within the hoistway 1 by means of the
10 traction machine 3. At an upper portion of the elevator
car 5, a car side pulley 6 is provided. End portions of
the main ropes 4 which are on the elevator car 5 side are
connected to a plurality of thimble rods 7 through the car
side pulley 6. The thimble rods 7 are connected to a
15 weighing device 8 within the machine room 2 and installed
on a floor surface of the machine room 2 or a traction
machine beam (a machine beam) 9. The elevator car 5 is
monitored in its position information in an encoder of the
traction machine or a speed governor, and the position
20 information is read into a control device 15.
A counterweight 10 is suspended within the hoistway 1
on the other sides of the main ropes 4 wound around the
sheave of the traction machine 3. The counterweight 10 is
comprised of a counterweight frame and a weight carried in
25 the frame and, at an upper portion of the counterweight
5
frame, a counterweight side pulley 11 is provided. End
portions of the main ropes 4 which are on the side of the
counterweight are connected to the thimble rods 7 similarly
to the other sides, and end portions of the thimble rods 7
5 are installed on the floor surface of the machine room 2 or
the traction machine beam 9 via elastic members for tension
adjustment. Between the traction machine 3 and the
counterweight side pulley 11, a beam pulley 12 may be
optionally provided.
10 The main ropes 4 are wound around the drive sheave of
the traction machine 3 via the car side pulley 6 from their
car side main rope end portions, and lead to their
counterweight side main rope end portions via the beam
pulley 12 and the counterweight side pulley 11 if they are
15 installed. The elevator car 5 and the counterweight 10 are
hung by 2:1 roping. On lower portions of the elevator car
5 and the counterweight 10, a compensation device 13 is
hung and, on the elevator car 5, a tail cord 14 is hung.
The thimble rods 7 at the car side rope end portions
20 are connected to the weighing device 8. Now assuming that,
in the 2:1 roping elevator, the weight of the elevator car
5 is Wc, the weight of the main ropes 4 between from the
drive sheave of the traction machine 3 to the car side rope
end portions is Wr, the weight of the tail cord 14 beneath
25 the elevator car 5 and the weight of the compensation
6
device 13 are Wt and Wk, respectively, and a load weight
within the elevator car 5 is W, a load P that is exerted on
the main rope end portions on the side of the elevator car
amounts to P = (Wc + Wr + Wt + Wk + W)/2. In this case,
5 the main ropes 4, the compensation device 13 and the tail
cord 14 change in their lengths according to the position
of the elevator car 5, so that the respective weights Wr,
Wt, Wk change according to the position of the elevator car
5. Calculation of these weights is performed by the
10 control device 15 which is installed in the machine room 2.
Next, Fig. 2 is a structure view of the weighing
device 8 installed to the end portions of the main ropes 4
on the car side. The end portions of the plural thimble
rods 7 on the car side are each installed to a main rope
15 receiving plate 16. The main rope receiving plate 16 is
supported by plate receiving springs 17. In this case, the
load P which is exerted on the end portions of the main
ropes on the car side is applied to the main rope receiving
plate 16, whereby deflection occurs in the plate receiving
20 springs 17. Of the load P, the weight Wr of the main ropes
4, the weights Wt, Wk of the weights of the tail cord 14
and the compensation device 13 which are applied to the
elevator car 5, and the load weight W within the elevator
car 5 change according to the position of the elevator car,
25 the weight of a passenger(s), etc., so that with this
7
change, a change in the position of the main rope receiving
plate 16 occurs. Also, a plurality of guide shafts 18 are
provided and configured to restrict lateral movement
relative to the main rope receiving plate 16 and limit
5 operation to a vertical direction.
An arm 19 has a fulcrum on the guide shaft 18 side,
is coupled to the main rope receiving plate 16, and changes
its inclination according to vertical displacement of the
main rope receiving plate 16. Incidentally, in this
10 embodiment, the arm 19 is attached to the guide shaft 18
via an arm attaching member 24. Also, in this embodiment,
the arm 19 is coupled to the main rope receiving plate 16
through a coupling member 23. The arm attaching member 24
and the coupling member 23 may be omitted, and the arm 19
15 may be attached directly to the guide shaft 18 and the main
rope receiving plate 16. Taking ease of attaching and
operation of the arm into consideration, it is desirable to
provide the attaching member 24 and the coupling member 23.
An angle measuring device 20 is provided at this arm 19 and
20 measures an angle of the arm. Angle information which is
measured by the angle measuring device 20 is read into the
control device 15. Fig. 3 is a view showing that the load
weight within the elevator car 5 increases, the deflection
occurs in the plate receiving springs 17, sinking occurs in
25 the main rope receiving plate 16, and inclination occurs in
8
the arm 19.
Now, the angle information in a case where the load
weight within the elevator car 5 is 0% and 100% is recorded
in the control device 15. Since at this time it is
5 possible to easily calculate a value of the load P exerted
on the end portions of the main ropes 4, it is possible to
easily define a relationship between the change of the load
P and the change of the angle information by the control
device 15. Since the load P that is exerted on the end
10 portions of the main ropes is P = (Wc + Wr + Wt + Wk + W)/2,
the load weight W within the elevator car 5 is W = 2P – (Wc
+ Wr + Wt + Wk). In contrast, since the load P can be
calculated from the angle information, and the weight Wr of
the main ropes and the weights Wt and Wk of the tail cord
15 14 and the compensation device 13 that are hung on the
elevator cage 5 can be easily calculated from the position
information of the elevator car 5, it is possible to
calculate the load weight of the elevator car 5 from these
pieces of information by the control device 15.
20 In the weighing device at the end portions of the
main ropes 4, periodical inspection after installation and
at the time of maintenance, periodical adjusting work after
tension adjustment of the main ropes, etc. are required.
At this time, for example, in a case where a detection
25 plate and a detector are provided and the weighing device
9
has a configuration in which the displacement of the main
rope receiving plate is measured from a gap between the
detection plate and the detector and load detection is
performed, it is required to perform readjusting of the
5 detection plate to the detection range of the detector,
record the load information and perform setting of the
detector to zero point. In contrast, the angle detector
which is proposed by the present invention does not require
provision of a detection target such as the detection plate
10 or the like at the time of detection. Therefore, in a case
where any detector having a wide measuring range is
selected, adjustment of an initial position and periodical
position checking and adjusting work are not required and
the adjustment can be finished by only setting the detector
15 to the zero point. Also, even if the measuring range of
the detector is narrow, the adjustment is made possible by
only changing the height of a fixed portion of the arm 19
and the guide shaft 18, and it is possible to cause the
adjusting work to be simplified.
20 Fig. 4 illustrates end portions of the main ropes on
the counterweight side which are the end portions of the
main ropes 4 on the other sides to which the weighing
device 8 is not attached. The end portions on the
counterweight side are each connected to the thimble rod 7,
25 at an end portion of which a discrete receiving spring 21
10
is provided, and the end portions of the main ropes are
configured to be arranged on the machine beam 9 or the
machine room floor surface. Since the end portions of the
thimble rods 7 on the elevator car side are not provided
5 with the discrete receiving springs 21, adjustment of
tension of respective ropes is performed by adjusting the
lengths of the receiving springs on the counterweight side.
Incidentally, while the elevator in which the machine
room 2 is provided at the upper portion of the hoistway 1,
10 a so-called elevator with a machine room is referred to in
Embodiment 1, the present invention can be also applied to
a machine roomless elevator which does not have a machine
room. Also, the present invention can be applied to a 1:1
roping elevator as well as the 2:1 roping elevator and, in
15 this case, the weighing device is installed on an upper
portion of the elevator car with the structure of the
weighing device 8 of Embodiment 1 being made upside down.
Embodiment 2
20 Fig. 5 is a view showing a structure of a weighing
device according to Embodiment 2 of the present invention.
In contrast with the weighing device of the elevator that
has the structure of Embodiment 1, the fulcrum of the arm
19 is provided with respect to a support member 22 which is
25 fixed to the machine beam 9. Also, with respect to the end
11
portions of the plural thimble rods 7, the main rope
receiving springs 21 for tension adjustment of the
respective main ropes 4 are provided. Incidentally, when
the weighing device is provided on the floor surface, the
5 support member 22 is installed on the floor surface.
In this Embodiment 2, in addition to the effects
brought about by Embodiment 1, the installation position of
the arm 19 is not restricted by the guide shafts 18 and the
tension adjustment of the respective main ropes 4 is
10 configured to be made possible even at the end portions of
the main ropes 4 on the car 5 side.
[Reference Signs List]
1: Hoistway, 2: Machine room, 3: Traction machine, 4:
15 Main rope, 5: Elevator car, 6: Car side pulley, 7: Thimble
rod, 8: Weighing device, 9: Traction machine beam (Machine
beam), 10: Counterweight, 11: Counterweight side pulley,
12: Beam pulley, 13: Compensation device, 14: Tail cord,
15: Control device, 16: Main rope receiving plate, 17:
20 Plate receiving spring, 18: Guide shaft, 19: Arm, 20:
rotation detector, 21: Discrete receiving spring.

Claims
We claim:
1. An elevator comprising: a traction machine (3); an
5 elevator car (5); a counterweight (10); a plurality of main
ropes (4) wound around the traction machine (3) and
suspending the elevator car (5) and the counterweight (10);
and a weighing device (8) provided at end portions of the
main ropes (4) on a side of the elevator car (5), the
10 weighing device (8) comprising a main rope receiver portion
(16) that supports the end portions of the plurality of
main ropes (4), and a main rope receiver supporting portion
(17) that supports the main rope receiver portion (16) and
changes its deflection amount due to a load applied to the
15 end portions of the main ropes (4), characterized in that
wherein the weighing device (8) is provided with an
arm (19) that changes its inclination by displacement of
the main rope receiver portion (16), and an angle detector
(20) that detects an angle of the arm (19).
20
2. The elevator as claimed in claim 1, wherein the arm
(19) of the weighing device (8) changes its inclination in
a vertical direction of a hoistway (1).
25 3. The elevator as claimed in claim 2, wherein the
13
weighing device (8) includes a main rope receiver guiding
portion (18) that restricts horizontal displacement of the
main rope receiver portion (16), and the arm (19) takes the
main rope receiver guiding portion (18) as a fulcrum.
5
4. The elevator as claimed in claim 2, wherein the arm
(19) takes a portion other than the weighing device (8) as
a fulcrum.
10 5. The elevator as claimed in claim 4, wherein the arm
(19) takes, as a fulcrum, a support member (22) which is
fixed on a floor surface or a machine beam (9) on which the
weighing device (8) is installed.
15 6. The elevator as claimed in claim 2, wherein the end
portions of the plurality of main ropes (4) on the side of
the elevator car (5) includes a tension adjusting portion
(21) that adjusts tension of each of the plurality of main
ropes (4).
20
7. The elevator as claimed in any one of claims 1 to 6,
wherein the elevator includes a control device (15) and a
position detection device for the elevator car (5), the
control device (15) calculating a load weight within the
25 elevator car (5) from information on a load exerted on the
14
end portions of the plurality of main ropes (4) which is
detected from an output of the angle detector (20) of the
weighing device, and position information of the elevator
car (5) which is detected from the position detection
5 device.