2. The electromagnetic brake release device for elevators 25 according to Claim 1, wherein a base for receiving the 1% reaction force of the ball screw nut during release of the electromagnetic brake is provided between the brake core and the thrust bearing. 5 3. The electromagnetic brake release device for elevators according to Claim 1 or 2, wherein the release lever is attachable to, or detachable from, the ball screw nut. 10 The electromagnetic brake release device for elevators according to Claim 1 or 2, wherein a flange portion with engaging holes arranged at regular intervals in a circumferential direction is fixed on a periphery of the ball screw nut; and 15 projections to engage with the engaging holes of the flange portion are provided at a tip of the release lever. The electromagnetic brake release device for elevators 20 according to Claim 1 or 2, wherein a polygonal engaging part is provided on a periphery of the ball screw nut; and an engaging hole to engage with the polygonal engaging part on the periphery of the ball screw nut is provided at a 25 tip of the release lever. mi

6. The electromagnetic brake release device for elevators ; according to Claim 1 or 2, comprising: a radial bearing provided on a periphery of the flange 5 portion; and a guide provided on a periphery of the radial bearing.

7. The electromagnetic brake release device for elevators i; according to Claim 1 or 2, wherein a shaft is provided to 10 connect the brake shoe and the ball screw.

8. ' The electromagnetic brake release device for elevators according to Claim 7, wherein a handle;which rotates the 15 ball screw and the shaft so as to thread-engage;with the brake shoe is provided at another end of the ball screw fastened to the shaft. Dated this 3""^ day of December 2014

Title of Invention
ELECTROMAGNETIC BRAKE RELEASE DEVICE FOR ELEVATORS 5
Technical Field [0001]
The present invention relates to an electromagnetic brake release device of a traction machine for moving up and 10 down a cage in an elevator and an elevator using a brake release device.
Background Art [0002]
15 In the past, in an elevator, a cage and a
counterweight have been connected by a rope, the rope has been wound around the sheave of a traction machine and the up and down control of the traction machine has been driven by a motor.
20 [0003]
A slight weight difference is provided between the cage and the counterweight so that slow ascending or descending movement in one direction is given to them when the traction machine stops driving. The traction machine
25 is provided with a brake disc coaxially with the sheave, and

braking is performed by an electromagnetic brake having a brake shoe engaged with it. [0004]
A normally-open type electromagnetic brake is used as 5 the electromagnetic brake and while the elevator is
operating., a solenoid is activated to keep the brake shoe and the brake disc separated from each other. And when stopping the elevator, by turning off the power to the electromagnetic brake, the brake shoe is pressed against the 10 brake disc by a brake spring to fix the traction machine sheave and stop the elevator and counterweight. When carrying out maintenance of the elevator, after the traction machine motor is stopped and the electromagnetic brake is turned off to fix the elevator in a prescribed positon, 15 there are cases when the electromagnetic brake is
temporarily released to make a fine adjustment of the
elevator position.
[0005]
As means to release the electromagnetic brake attached 20 to the elevator traction machine, a structure which pulls up a releasing bolt using the leverage of a release lever has been generally used previously. [0006]
For example. Patent Literature 1 described below 25 (PTLl) discloses an electromagnetic brake when the fixed

core of an electromagnet is not magnetized, a lining plate provided on a brake shaft is held between a fixed brake surface and a movable brake plate by spring pressure to perform braking, in which by engaging an engaging part 5 provided on a loosening pin with the movable plate by operation of ,a release lever and rotating a cantilever (lever) type release lever rotatably supported on the loosening pin by means of a shaft, the spring generating pressing force to the lining plate is compressed to move the 10 movable plate in a brake loosening direction.
Citation List Patent Literature
PTL 1: Japanese Utility Model Application Laid-Open No. 15 Sho49 (1984)-9987
Summary of Invention Technical Problem [0008]
20 In the structure in PTLl, when a large electromagnetic brake with a large spring force is released, in order to use the same operating force for release as before and perform brake releasing operation with high accuracy, the length of the release lever must be increased. However, if the
25 release lever increases, in order to provide the same gap

between the lining and brake disc as before, a lever stroke longer than in the conventional structure is required and the maintenance space in front of the brake must be large. In addition, if the length of the lever increase, the lever 5 weight would increase -and also the distance between the brake .and the operator would increase, this brings a significant deterioration in operability. [0009]
Therefore, the present invention has been made in view 10 of the above problem and has an object to provide a brake release device of an electromagnetic brake which can accurately release the brake with a smaller force than in a lever-type release lever and can reduce the maintenance space in front of the brake. 15
Solution to Problem [0010]
In order to solve the above problem, an electromagnetic brake release device according to the 20 present invention includes a ball screw connected to a brake shoe assembly comprised of a brake shoe and a rod contained in a brake core, a ball screw nut thread-engaged with the ball screw, a thrust bearing for receiving the reaction force of the ball screw nut during release, and a release 25 lever attachable to the ball screw nut.

Advantageous Effects of Invention [0011]
According to the electromagnetic brake release device 5 in the present invention, the brake shoe is moved in'the
loosening direction using the ball screw and the ball screw nut, so the electromagnetic brake can be released accurately with a smaller force than in a cantilever-type release device and the release lever can be shortened. 10 [0012]
In addition, in brake releasing operation, the brake can be released by rotating the release lever around the brake core, so maintenance space in front of the brake core can be reduced as compared with a cantilever type brake 15 release device. [0013]
Furthermore, by relaxing the force applied to the release lever, the release of the brake is cancelled immediately due to the resilience of the ball screw, so even 20 if an abnormal situation such as a free run of the cage, etc. should occur, the braking force of the brake can be immediately recovered and high safety is ensured.
Brief Description of Drawings 25 [0014]

• Figure 1 is a schematic view showing an elevator to which the present invention is applied.
Figure 2 is a front view showing an electromagnetic brake to which a brake release device and a release lever in 5 Example 1 of the- present invention are attached.
Figure .3 is a .side view showing the electromagnetic brake to which the brake release device and the release lever in Example 1 of the present invention are attached.
Figure 4A is a front view showing the release lever of 10 the brake release device in Example 1 of the present invention.
Figure 4B is a side view showing the release lever of the brake release device in Example 1 of the present invention. 15 Figure 5 is a sectional view showing the brake release device in Example 1 of the present invention.
Figure 6 is a view on arrow A in Fig. 5.
Figure 7 is a side view showing an electromagnetic brake to which a brake release device and a release lever in 20 Example 2 of the present invention are attached.
Figure 8 is a front view showing the release lever of the brake release device in Example 2 of the present invention.
25 Description of Embodiments

[0015]
Next, an electromagnetic brake release device according to an embodiment of the present invention will be described referring to examples and drawings. The present 5 invent ion ' is not limited to the example s below. [0016]
Fig. 1 is a schematic view showing the configuration of an elevator 1 according to this embodiment. The elevator 1 according to this embodiment includes a cage 120 which 10 moves up and down in an elevator shaft 110 formed in a
building structure, and a counterweight 14 0 connected to the
cage 120 by a rope 130.
[0017]
Further it includes a traction machine 100 which is 15 installed at the top of the elevator shaft 110 and around
which the rope 13 0 is wound to move up and down the cage 12 0, and a deflection pulley 150 which is installed near the traction machine 100 and on which the rope 130 is loaded.
20 [0018]
Fig. 2 is a front view showing an electromagnetic brake of a traction machine to which a brake release device and a release lever in Example 1 of the present invention 25 are attached.

[0019]
A brake disc 31 is located at an axial end of the traction machine 100. F denotes an elevator frame. 34 denotes a brake support base. The brake support base 34 is 5 provided -with a brake core 22 having an electromagnetic brake-for braking the brake disc 31.. .39 denotes a brake release device for releasing the electromagnetic brake by manual operation. 2 9 denotes a release lever. By turning the release lever 29 in the direction of the arrow 10 (clockwise), the electromagnetic brake after braking action is released. [0020]
Fig. 3 is a side view showing the electromagnetic brake to which the brake release device 3 9 and the release 15 lever 2 9 in Example 1 of the present invention are attached. By turning the release lever 2 9 attached to the ball screw nut of the brake release device 3 9 clockwise, the ball screw nut and the brake core 22 are made to contact each other and since a ball screw is integrally connected to a brake shoe 20 assembly 20, the brake shoe assembly 2 0 compresses a brake spring 3 3 to make a gap 3 8 between brake shoes 32a, 32b and the brake disc 31 and release the braking force of the brake. [0021]
Fig. 4A is a front view showing the release lever of 25 the brake release device in Example 1 of the present

invention. Fig. 4B is a side view showing the release lever of the brake release device in Example 1 of the present invention. [0022] 5 The release lever 29 includes a lever portion 2 7 for transmitting .the ..torque upon release and a lever tip portion 2 8 with a doughnut shaped hole 3 7 which is connectable to the ball screw nut of the brake release device 3 9 and can be attached to the faucet joint portion of the ball screw nut. 10 [0023]
Fig. 5 is a sectional view showing details of the brake release device in Example 1 of the present invention. Fig. 6 is a view on arrow A in Fig. 5. [0024] 15 In Fig. 5, the electromagnetic brake release device in Example 1 includes: a shaft 10 with a thread 43 made thereon which can be inserted into the threaded hole 41 of the brake shoe assembly 2 0 which is contained in a hole 3 6 made in the center of the brake core 22 and has brake shoes at the tip; 20 a base 11 as a spacer member for receiving the reaction
force to the tension of the shaft 10 during release of the brake and transmitting it to the brake core 22; a ball screw 12 fastened to the shaft 10; a ball screw nut 18 thread-fitted to the ball screw 12; a flange portion 13 press-25 fitted to the outside of the ball screw nut 18; a radial

10
bearing 14 press-fitted to the outside of the flange portion
13; a guide 15 fastened with the outer ring of the radial
bearing 14; a handle 16 attached at one end of the ball
screw 12; and a thrust bearing 17 fastened between the guide 5 15 and the base 11, and receives the reaction force of the
ball ..screw nut 18.
[0025]
The shaft 10 is a connecting member which can be
omitted by connecting the brake shoe assembly 2 0 and the 10 ball screw 12 directly. 44 denotes a ball stopper.
[0026]
On the flange portion 13 fixed on the ball screw nut
18, engaging holes 3 0 arranged on the same circumference in
the circumferential direction and a faucet joint portion 26 15 are provided.
[0027]
The base 11, flange portion 13, radial bearing 14,
guide 15, thrust bearing 17, and ball screw nut 18 are
integrated to form a nut assembly 21. The nut assembly 21 20 has a structure which can move on the ball screw 12 while
rotating in the axial longitudinal direction.
[0028]
Here, the thread 43 at the tip of the shaft 10 is
screwed into the threaded hole 41 of the brake shoe assembly 25 2 0 by turning the handle 16 and a shaft contact part 19 is

fixed by abutting it against the brake shoe assembly 20. Then the nut assembly 21 is moved toward the brake core 22 while being rotated, until the base 11 and the brake core 22 are made to contact each other. 5 [0029]
,In Figs. 4A and 4B, on the lever tip portion 2S of the release lever 29, two projections 23, which are located on the same circumference as a plurality of engaging holes 30 provided on the flange portion 13 attached to the ball screw 10 nut 18, are provided at intervals of 18 0 degrees. The hole 37 of the lever tip portion 28 is inserted from the handle 16 side of the brake release device 3 9 and fitted to the faucet joint portion 26 of the flange portion 13. The flange portion 13 has twelve engaging holes 3 0 on the same
15 circumference at intervals of 3 0 degrees. [0030]
Since the phase angles of the engaging holes 3 0 of the flange portion 13 of the ball screw nut 18 coincide with the projections 23 of the release lever 29, the projections 23
20 of the release lever 2 9 can be inserted into the engaging holes 30 of the flange portion 13. Since the twelve engaging holes 3 0 of the flange portion 13 are made at intervals of 3 0 degrees on the same circumference, releasing operation by the release lever 29 can be performed at an
25 angle at which releasing operation is the easiest.


'S

12
Example 2 [0031]
Fig. 7 is a side view showing an electromagnetic brake 5 to which a brake release device and a release lever in ,
Example 2 of the present invention.are attached. Fig. 8 is a front view showing the release lever of the brake release device in Example 2 of the present invention. [0032] 10 As shown in Fig. 8, the release lever 4 8 has a regular hexagonal engaging hole 49 in a lever tip portion 50 and has a lever portion 47. On the other hand, the outer periphery of the ball screw nut 18A of the brake release device 3 9A has a regular hexagonal shape so as to engage with the 15 regular hexagonal hole 4 9 in the lever tip portion 5 0 of the release lever 48. Here, by engaging the release lever 4 8 with the ball screw nut 18A of the brake release device 3 9A, the brake release device 3 9A can be rotated to release the electromagnetic brake in the same way as in Example 1. 20 [0033]
The release lever and the ball screw nut of the brake release device may be connected by any other method that allows transmission of the rotation torque. For example, a method in which the release lever is inserted in a lateral 25 face of the brake release device may be adopted.

13
[0034]
In the above example, the release lever is attachable to, or detachable from, the brake release device and operated manually by the operator. Here, the release lever 5 is not limited to the manual type but it may be, for example, an electric powered release lever which has a socket to engage with a ball screw nut driven by a battery motor. In this case, the release lever body may be locked on the brake release device in the rotating direction by certain means to 10 receive a reaction force so that electromagnetic brake releasing operation can be performed by simple button operation. [0035]
In addition, the attachment/detachment method for the 15 release lever and the ball screw nut of the brake release device is excellent in operability and in the first place, when the ball screw method is adopted, the necessary rotation torque is reduced and the release lever can be shortened, so there is no problem with the use of a compact 20 release lever permanently fixed on the ball screw nut. [0036]
Here, if an emergency situation such as a free run which might happen during brake releasing operation should occur, the braking force of the brake must be recovered 25 immediately to stop the elevator safely.

14
[0037]
In the brake release device according to the present invention, by releasing the hold on the release lever, namely cancelling the force applied to the release lever, 5 the release of the brake is stopped due to the resilience of the ball screw, so even if an abnormal situation such as a free run should occur, the braking force of the brake can be immediately recovered and high safety is ensured. [0038] 10 Furthermore, if a foreign substance intrudes in the gap between the ball screw and the ball screw nut, smooth moving of the ball screw may be disturbed and the recovering force of the ball screw may be impaired. In that case, if an emergent situation such as a free run as mentioned above 15 should occur, it might happen that the braking force of the brake cannot be recovered and a serious accident might result, so it is desirable to provide a seal structure for preventing intrusion of foreign substances, between the ball screw and the nut. 20
Reference Signs List [0039]
1...elevator, 10...shaft, 25 11...base,

15
12...ball screw,
13...flange portion,
14...radial bearing,
15...guide, 5 16...handle,
17...thrust bearing,
18...ball screw nut, 20...brake shoe assembly, 21...nut assembly, 10 22...brake core, 23...projection, 26...faucet joint portion, 27...lever portion, 8...lever tip portion, 15 29, 48... release lever, 3 0...engaging hole, 31...brake disc, 32a, 32b...brake shoe, 33...brake spring, 20 34...brake support base, 37, 49...engaging hole, 39, 3 9A...brake release device, 44...ball stopper, 100...traction machine, 25 110 ... elevator shaft,

120...cage, 13 0...rope, 140...counterweight

16

n

WE CLAIM:-

An/electromagnetic brake release device for elevators comprising: 5 a traction machine which moves up and down an elevator cage and a counterweight;
an electromagnetic brake which brakes a brake disc provided in the traction machine through a brake shoe and stops the traction machine by an elastic force of a spring; 10 and
an electromagnetic brake release device which releases braking by the electromagnetic brake against the elastic force of the spring,
the electromagnetic brake release device comprising: 15 a brake core which houses the brake shoe;
a ball screw connected to the brake shoe and a ball screw nut which is thread-engaged with the ball screw;
a thrust bearing which receives a reaction force of the ball screw nut during release of the electromagnetic 20 brake; and
a release lever which is attached to the ball screw nut to rotate the ball screw nut.
2. The electromagnetic brake release device for elevators 25 according to Claim 1, wherein a base for receiving the

1%
reaction force of the ball screw nut during release of the electromagnetic brake is provided between the brake core and the thrust bearing.
5 3. The electromagnetic brake release device for elevators according to Claim 1 or 2, wherein the release lever is attachable to, or detachable from, the ball screw nut.
10 The electromagnetic brake release device for elevators
according to Claim 1 or 2, wherein
a flange portion with engaging holes arranged at
regular intervals in a circumferential direction is fixed on
a periphery of the ball screw nut; and 15 projections to engage with the engaging holes of the
flange portion are provided at a tip of the release lever.
The electromagnetic brake release device for elevators 20 according to Claim 1 or 2, wherein
a polygonal engaging part is provided on a periphery of the ball screw nut; and
an engaging hole to engage with the polygonal engaging part on the periphery of the ball screw nut is provided at a 25 tip of the release lever.

mi
6. The electromagnetic brake release device for elevators
; according to Claim 1 or 2, comprising:
a radial bearing provided on a periphery of the flange 5 portion; and
a guide provided on a periphery of the radial bearing.
7. The electromagnetic brake release device for elevators
i; according to Claim 1 or 2, wherein a shaft is provided to
10 connect the brake shoe and the ball screw.
8. '
The electromagnetic brake release device for elevators according to Claim 7, wherein a handle;which rotates the 15 ball screw and the shaft so as to thread-engage;with the brake shoe is provided at another end of the ball screw fastened to the shaft.
Dated this 3""^ day of December 2014