SPEED GOVERNOR DEVICE OF ELEVATOR

Abstract

 A sheave shaft is rotatably supported by a pedestal fixed to a car. The pedestal is provided with a speed governor sheave around which a speed governor rope stretched vertically within a hoistway is wound. The speed governor sheave is provided with a flyweight, which is displaced from a normal position to a trip position due to a centrifugal force resulting from rotation of the speed governor sheave. The sheave shaft is provided with an operational member displaceable in an axial direction of the sheave shaft. The normal position of the flyweight is adjusted through displacement of the operational member with respect to the sheave shaft. A cam member, which is inclined with respect to a direction in which the car is moved, is provided within the hoistway. The car is provided with an operational force transmitting member for displacing the operational member. The operational force transmitting member has an engaging portion engaged with the operational member in the axial direction of the sheave shaft, and a driven portion coupled to the engaging portion to be guided along the cam member through a movement of the car.

Description

Technical Field

[0001] The present invention relates to a speed governor apparatus for an elevator having a speed governor sheave that is rotated as a car moves.

Background Art

[0002] In a conventional speed governor for an elevator, a flyweight provided on a speed governor sheave may be turned due to a centrifugal force resulting from rotation of the speed governor sheave so as to detect that a speed of a car has reached a predetermined overspeed. The car is mounted with an emergency stop device for preventing the car from falling. A speed governor rope coupled to the emergency stop device is wound around the speed governor sheave. Accordingly, the speed governor sheave is rotated at a speed corresponding to the speed of the car.

[0003] In this conventional speed governor for an elevator, when a rotational speed of the speed governor sheave reaches a first overspeed, a car stop switch is actuated due to the turning of the flyweight. Owing to actuation of the car stop switch, a power source of a drive device for an elevator is shut off, so the car is stopped by a brake device for the drive device. When the rotational speed of the speed governor sheave reaches a second overspeed, the flyweight is further turned, so a braking mechanism for braking a speed governor rope is operated. Due to the operation of the braking mechanism, the speed governor rope is braked. As a result of the braking of the speed governor rope, the emergency stop device is operated (see Patent Document 1).

[0004] Patent Document 1: JP 2001-106454 A

Disclosure of the Invention

Problems to be solved by the Invention

[0005] In the conventional speed governor for an elevator constructed as described above, however, setting of a first overspeed and a second overspeed cannot be adjusted during operation of an elevator. Accordingly, the overspeeds set for the speed governor are made constant regardless of the position of the car. Thus, even when the car is moved in an upper portion or a lower portion of the hoistway where the speed of the car is normally lowered, the speed governor cannot be operated unless the speed of the car becomes extremely high. Therefore, a shock absorber for absorbing a shock to the car cannot be reduced in size, so the depth dimension of a pit portion of the hoistway in which the shock absorber is installed cannot be reduced. Further, an overhead dimension for allowing the car to overshoot or jump is also increased and cannot be reduced.

[0006] The present invention has been made to solve the problems as described above, and it is therefore an object of the present invention to obtain a speed governor apparatus for an elevator which allows a set overspeed for stopping a car as an emergency measure to be adjusted easily and more reliably.

Means for solving the Problems

[0007] A speed governor apparatus for an elevator according to the present invention includes: a sheave shaft rotatably supported by a pedestal mounted on a car; a speed governor sheave designed to be rotatable integrally with the sheave shaft and having wound therearound a speed governor rope stretched vertically within a hoistway, for being rotated in accordance with a movement of the car; a flyweight provided on the speed governor sheave and designed to be displaceable with respect to the speed governor sheave between a normal position and a trip position that is located radially outward of the speed governor sheave with respect to the normal position, for being displaced from the normal position to the trip position due to a centrifugal force resulting from rotation of the speed governor sheave; a braking mechanism mounted on the car, for being operated due to displacement of the flyweight to the trip position to arrest the speed governor rope; an adjusting lever designed to be turnable with respect to the sheave shaft in a circumferential direction of the speed governor sheave, for being turned with respect to the sheave shaft to displace the flyweight and adjust the normal position; an operational member designed to be displaceable with respect to the sheave shaft in an axial direction of the sheave shaft; an interlocking mechanism for interlocking the operational member and the adjusting lever with each other to convert displacement of the operational member into a turning movement of the adjusting lever; a cam member provided within the hoistway and inclined with respect to a direction in which the car is moved; and an operational force transmitting member having an engaging portion engaged with the operational member in the axial direction of the sheave shaft, and a driven portion coupled to the engaging portion to be guided along the cam member through a movement of the car, for displacing the operational member in the axial direction of the sheave shaft through displacement of the engaging portion resulting from guide of the driven portion by the cam member.

Brief Description of the Drawings

[0008] 

Fig. 1 is a schematic diagram showing an elevator apparatus according to Embodiment 1 of the present invention.

Fig. 2 is a front view showing the speed governor of Fig. 1.

Fig. 3 is a back view showing the speed governor of Fig. 2.

Fig. 4 is a partial cross-sectional view showing an essential part of the speed governor of Fig. 3.

Fig. 5 is an exploded perspective view showing an essential part of the speed governor of Fig. 3.

Fig. 6 is a plan view showing an essential part of the elevator apparatus of Fig. 1.

Fig. 7 is a lateral view showing an essential part of the elevator apparatus of Fig. 6.

Fig. 8 is a front view showing an essential part of the lower portion of the car of Fig. 7.

Fig. 9 is a cross-sectional view taken along the line IX-IX of Fig. 6.

Fig. 10 is a graph showing a relationship among the speed of the car, the first overspeed, the second overspeed, and the distance from a terminal floor to the car during normal operation of the elevator of Fig. 1.

Fig. 11 is a cross-sectional view showing an essential part of a speed governor apparatus for an elevator according to Embodiment 2 of the present invention.

Fig. 12 is a schematic view showing an essential part of the speed governor apparatus as viewed along a radial direction of the speed governor sheave of Fig. 11.

Best Mode for carrying out the Invention

[0009] Preferred embodiments of the present invention will be described hereinafter with reference to the drawings.

Embodiment 1

[0010] Fig. 1 is a schematic diagram showing an elevator apparatus according to Embodiment 1 of the present invention. In the figure, a drive device 2 is installed in an upper portion within a hoistway 1. The drive device 2 has a drive sheave 2a. A main rope 3 is wound around the drive sheave 2a. A car 4 and a counterweight 5 are suspended within the hoistway 1 by means of the main rope 3. A pair of car guide rails 6 for guiding the raising/lowering of the car 4, and a pair of counterweight guide rails (not shown) for guiding the raising/lowering of the counterweight 5 are installed within the hoistway 1.

[0011] The car 4 is mounted with a pair of emergency stop devices 7 for forcibly stopping the car 4 from moving. The car 4 is also mounted with a speed governor 8 for detecting an overspeed of the car 4 to operate the respective emergency stop devices 7, and a rotatable return pulley 9 provided in the vicinity of the speed governor 8. The respective emergency stop devices 7, the speed governor 8, and the return pulley 9 are disposed on a lower portion of the car 4.

[0012] A speed governor rope 10 stretched vertically within the hoistway 1 is wound around the speed governor 8 and the return pulley 9. An upper fixation member 11 is fixed to upper portions of the car guide rails 6, and a lower fixation member 12 is fixed to lower portions of the car guide rails 6. The speed governor rope 10 is connected at an upper end thereof to the upper fixation member 11 via a spring (an elastic body), and at a lower end thereof to the lower fixation member 12 via a spring (an elastic body). That is, the speed governor rope 10, which extends from the lower fixation member 12 to the upper fixation member 11, is sequentially wound around the speed governor 8 and the return pulley 9. Tensile forces are applied to the speed governor rope 10 due to elastic forces of the respective springs.

[0013] Fig. 2 is a front view showing the speed governor 8 of Fig. 1. Fig. 3 is a back view showing the speed governor 8 of Fig. 2. In the figures, a pedestal 13 is fixed to the lower portion of the car 4. A horizontally extending sheave shaft 14 is rotatably supported on the pedestal 13. A speed governor sheave 15 around which the speed governor rope 10 is wound is fixed to the sheave shaft 14. The speed governor sheave 15 is rotated integrally with the sheave shaft 14.

[0014] A pair of flyweights 17, which can turn around pins 16, respectively, are provided on a lateral face of the speed governor sheave 15. By being turned around the pins 16, the flyweights 17 can each be displaced between a normal position and a trip position that is located radially outward of the speed governor sheave 15 with respect to the normal position. The flyweights 17 are each turned from the normal position to the trip position due to a centrifugal force resulting from rotation of the speed governor sheave 15. The respective flyweights 17 are coupled to each other via a link 18.

[0015] An actuating pawl 19 is fixed to one end of one of the flyweights 17. The actuating pawl 19 is displaced radially outward of the speed governor sheave 15 due to the turning of the flyweight 17 from the normal position to the trip position.

[0016] The pedestal 13 is fitted with a car stop switch 20 for stopping the supply of power to the drive device 2 and operating a brake device (not shown) for the drive device 2. The car stop switch 20 has a switch body 21, and a switch lever 22 provided on the switch body 21 to be operated by the actuating pawl 19. The switch lever 22 is operated by the actuating pawl 19 when the flyweight 17 is turned to a stop operation position located between the normal position and the trip position. The flyweight 17 is turned to the stop operation position when the speed of the car 4 has reached a first overspeed (which is normally about 1.3 times as high as a rated speed), and to the trip position when the speed of the car 4 has reached a second overspeed (which is normally about 1.4 times as high as the rated speed).

[0017] The speed governor sheave 15 is provided with a trip lever 24, which can turn around a shaft 23 extending parallel to the pins 16. A part of the trip lever 24 abuts on one of the flyweights 17. The trip lever 24 is turned around the shaft 23 through the turning of the flyweight 17. The shaft 23 is provided with a torsion spring (not shown) for urging the trip lever 24 in such a direction that the trip lever 24 comes into abutment on the flyweight 17.

[0018] A ratchet 25, which can rotate around the sheave shaft 14, is provided on the pedestal 13 (FIG. 3). The rachet 25 is adapted to be rotated with respect to the sheave shaft 14. A plurality of teeth are provided on an outer peripheral portion of the ratchet 25.

[0019] One of the pins 16 is provided with an engaging pawl 26 for selectively engaging one of the trip lever 24 and the ratchet 25 in such a manner that the engaging pawl 26 is free to be turned. The engaging pawl 26 is urged in such a direction as to engage the ratchet 25 by a draft spring (not shown). When the flyweight 17 is located at the normal position, the engaging pawl 26 is engaged with the trip lever 24 and opened/separated from the ratchet 25. When the flyweight 17 has been turned to the trip position, the engaging pawl 26 is disengaged from the trip lever 24, turned due to a spring force of the draft spring, and then engaged with the ratchet 25.

[0020] The pedestal 13 is turnably fitted with an arm 27. The arm 27 is turnably fitted with a shoe 28, which is pressed against the speed governor sheave 15 via the speed governor rope 10. A spring shaft 29 is passed through a tip 27a of the arm 27 in a displaceable manner. A connection link 30, which is turnably connected to the ratchet 25, is fixed to one end of the spring shaft 29. A spring receiving member 31 is provided at the other end of the spring shaft 29. A presser spring 32 for pressing the shoe 28 against the speed governor rope 10 is provided between the tip 27a of the arm 27 and the spring receiving member 31.

[0021] The ratchet 25 is rotated in the same direction as the speed governor sheave 15 due to engagement with the engaging pawl 26 during rotation of the speed governor sheave 15. Thus, the arm 27 is turned in such a direction that the shoe 28 is pressed against the speed governor sheave 15. When the shoe 28 is pressed against the speed governor sheave 15 via the speed governor rope 10, the speed governor rope 10 is thereby arrested.

[0022] A braking mechanism 33 for arresting the speed governor rope 10 has the trip lever 24, the ratchet 25, the engaging pawl 26, the arm 27, the shoe 28, the spring shaft 29, the connection link 30, the spring receiving member 31, and the presser spring 32.

[0023] The sheave shaft 14 is provided with an adjusting lever 34, which can be turned with respect to the sheave shaft 14 in a circumferential direction of the speed governor sheave 15. The adjusting lever 34 has a lever body 35, a turn regulating portion 37, and a lever strip 38. The lever body 35 includes a cylinder portion 35a inside which the sheave shaft 14 is passed. The turn regulating portion 37 is provided on an outer peripheral portion of the lever body 35, and is provided with a long hole 36 extending in the circumferential direction of the speed governor sheave 15. The lever strip 38 is provided on the outer peripheral portion of the lever body 35, and extends radially outward of the lever body 35.

[0024] A pin 39, which is passed through the long hole 36, is fixed to the lateral face of the speed governor sheave 15. The pin 39 can slide within the long hole 36 in a longitudinal direction thereof. The turn regulating portion 37 is slid with respect to the pin 39 through the turning of the adjusting lever 34 with respect to the sheave shaft 14. Thus, the turning amount of the adjusting lever 34 is regulated.

[0025] The lever strip 38 is displaced in the circumferential direction of the speed governor sheave 15 through the turning of the lever body 35. A coupling body 40 for coupling the one of the flyweights 17 to the adjusting lever 34 is connected between the other end of the flyweight 17 and the lever strip 38. The coupling body 40 has an extendable rod 41 and a balance spring 42. The extendable rod 41, which can be extended and contracted, is connected between the flyweight 17 and the lever strip 38. The balance spring 42, which is provided on the extendable rod 41, urges the flyweight 17 in such a direction as to act against a centrifugal force resulting from rotation of the speed governor sheave 15.

[0026] The flyweight 17 and the adjusting lever 34 are interlocked with each other by the coupling body 40. Accordingly, the normal position of the flyweight 17 can be adjusted toward or away from the trip position through the turning of the adjusting lever 34. In other words, the turning angle (turning distance) of the flyweight 17 during displacement thereof from the normal position to the trip position can be adjusted by the adjusting lever 34. The magnitudes of the first overspeed and the second overspeed for stopping the car 4 as an emergency measure can be adjusted through the turning of the adjusting lever 34.

[0027] Fig. 4 is a partial cross-sectional view showing an essential part of the speed governor 8 of Fig. 3. Fig. 5 is an exploded perspective view showing an essential part of the speed governor 8 of Fig. 3. The sheave shaft 14 is provided with an operational member 43, which can be displaced in an axial direction of the sheave shaft 14. The operational member 43 has a tube portion 44 surrounding the sheave shaft 14, and a plate-shaped disc portion 45 provided on an outer peripheral portion of the tube portion 44. The disc portion 45 is disposed perpendicularly to the axial direction of the sheave shaft 14.

[0028] An interlocking mechanism 46 for interlocking the operational member 43 with the adjusting lever 34 is provided between the sheave shaft 14 and the lever body 35. The interlocking mechanism 46 converts displacement of the operational member 43 with respect to the sheave shaft 14 into a turning movement of the adjusting lever 34 with respect to the sheave shaft 14. In this example, when the operational member 43 is displaced toward the speed governor sheave 15, the interlocking mechanism 46 thereby turns the adjusting lever 34 in such a direction that the normal position of the flyweight 17 moves away from the trip position. When the operational member 43 is displaced away from the speed governor sheave 15, the interlocking mechanism 46 thereby turns the adjusting lever 34 in such a direction that the normal position of the flyweight 17 moves toward the trip position.

[0029] The interlocking mechanism 46 has a displacement body 47, a sheave shaft-side spline portion 48, and a lever-side spline portion 49. The displacement body 47 is integrated with the operational member 43. The sheave shaft-side spline portion 48, which is provided on an outer peripheral face of the sheave shaft 14, serves as a first guide portion for turning the displacement body 47 with respect to the sheave shaft 14 when the displacement body 47 is displaced with respect to the sheave shaft 14. The lever-side spline portion 49, which is provided on an inner peripheral face of the cylinder portion 35a, turns the cylinder portion 35a with respect to the displacement body 47 in a direction opposite to a direction in which the displacement body 47 is turned by the sheave shaft-side spline portion 48 when the displacement body 47 is displaced with respect to the sheave shaft 14.

[0030] An internal gear spline portion 50, which is fitted to the sheave shaft-side spline portion 48, is provided on an inner peripheral face of the displacement body 47. An external gear spline portion 51, which is fitted to the lever-side spline portion 49, is provided on an outer peripheral face of the displacement body 47. That is, the displacement body 47 is spline-coupled to the lever body 35 and the sheave shaft 14, respectively. Thus, the displacement body 47 can be displaced while being turned with respect to the sheave shaft 14 and the cylinder portion 35a in the axial direction of the sheave shaft 14.

[0031] Tooth traces of the sheave shaft-side spline portion 48 and the lever-side spline portion 49 are inclined with respect to the axial direction of the sheave shaft 14. That is, the sheave shaft-side spline portion 48 and the lever-side spline portion 49 are designed as helical spline portions. The tooth trace of the sheave shaft-side spline portion 48 is inclined (twisted) in a direction opposite to a direction in which the tooth trace of the lever-side spline portion 49 is inclined (twisted). Furthermore, the tooth trace of the sheave shaft-side spline portion 48 is different in inclination angle (twist angle) from the tooth trace of the lever-side spline portion 49.

[0032] When the displacement body 47 is displaced with respect to the sheave shaft 14 in the axial direction of the sheave shaft 14, the cylinder portion 35a is turned with respect to the displacement body 47 simultaneously with the turning of the displacement body 47 with respect to the sheave shaft 14. The direction in which the displacement body 47 is turned with respect to the sheave shaft 14 is reverse to the direction in which the cylinder portion 35a is turned with respect to the displacement body 47. Accordingly, when the displacement body 47 is displaced in the axial direction of the sheave shaft 14, the adjusting lever 34 is turned with respect to the sheave shaft 14 by a difference between a turning angle of the displacement body 47 with respect to the sheave shaft 14 and a turning angle of the cylinder portion 35a with respect to the displacement body.

[0033] Fig. 6 is a plan view showing an essential part of the elevator apparatus of Fig. 1. Fig. 7 is a lateral view showing an essential part of the elevator apparatus of Fig. 6. Fig. 8 is a front view showing an essential part of the lower portion of the car 4 of Fig. 7. Moreover, Fig. 9 is a cross-sectional view taken along the line IX-IX of Fig. 6. In the figures, operational guide rails (cam members) 55, which are inclined with respect to the car guide rails 6, are provided in each of the upper portion within the hoistway 1 and the lower portion within the hoistway 1. That is, the operational guide rails 55 are inclined with respect to the moving direction of the car 4. The operational guide rails 55 are inclined with respect to the car guide rails 6 such that the horizontal distance from the car guide rails 6 decreases as the distance from a terminal of the hoistway 1 decreases. The operational guide rail 55 are fixed to the car guide rails 6. In addition, the operational guide rails 55 are disposed outside a region of the car 4 when the hoistway 1 is vertically projected.

[0034] The pedestal 13 is provided with a vertically extending turning shaft 56. An operational arm (an operational force transmitting member) 57, which can turn around the turning shaft 56, is supported by the pedestal 13. The operational arm 57 has a rod-shaped arm portion 58, an engaging portion 59, and a driven roller (a driven portion) 60. The arm portion 58 is turnably provided on the turning shaft 56. The engaging portion 59, which is provided at one end of the arm portion 58, is engaged with the disc portion 45 in the axial direction of the sheave shaft 14. The driven roller 60, which is provided at the other end of the arm portion 58, is guided along the operational guide rails 55 through a movement of the car 4. The turning shaft 56 is provided with an intermediate region of the arm portion 58.

[0035] When the driven roller 60 is guided along the operational guide rails 55, the operational arm 57 is thereby turned around the turning shaft 56. In this example, when the driven roller 60 is guided away from the car guide rails 6, the engaging portion 59 is thereby displaced toward the speed governor sheave 15. When the driven roller 60 is guided toward the car guide rails 6, the engaging portion 59 is thereby displaced away from the speed governor sheave 15.

[0036] The operational member 43 is displaced in the axial direction of the sheave shaft 14 through displacement of the engaging portion 59 resulting from the turning of the operational arm 57. That is, when the car 4 is moved toward the terminal of the hoistway 1 in the upper portion or the lower portion within the hoistway 1, the operational member 43 is displaced away from the speed governor sheave 15. When the car 4 is moved away from the terminal of the hoistway 1, the operational member 43 is displaced toward the speed governor sheave 15.

[0037] The pedestal 13 is provided with a support shaft 61 extending parallel to the sheave shaft 14. The support shaft 61 is turnably provided with a link member 62. The return pulley 9 is rotatably provided at a tip of the link member 62. The return pulley 9 is rotated around a horizontally extending return pulley shaft 63. That is, the return pulley 9 is displaced with respect to the car 4 due to the turning of the link member 62 around the support shaft 61.

[0038] The respective emergency stop devices 7 are mounted on an emergency stop frame 64, which is fixed on the lower portion of the car 4. Each of the emergency stop devices 7 has a wedge 65 and a gripper piece 66. The wedge 65 can move into contact with and away from the car guide rail 6. The gripper piece 66 guides the wedge 65 in such directions that the wedge 65 moves into contact with and away from the car guide rail 6. When the wedge 65 comes into contact with the car guide rail 6 and breaks into a space between the gripper piece 66 and the car guide rail 6, each of the emergency stop devices 7 is thereby operated. Amovement of the car 4 is forcibly braked through the operation of the respective emergency stop devices 7. When the wedge 65 moves away from the car guide rail 6, the operation of each of the emergency stop devices 7 is thereby canceled.

[0039] An interlocking shaft 67 for interlocking the respective emergency stop devices 7 with each other is turnably pivoted on the emergency stop frame 64. The interlocking shaft 67 is arranged parallel to a line connecting the respective emergency stop devices 7 to each other. Emergency stop levers 68 are provided at both ends of the interlocking shaft 67. Each of the emergency stop levers 68 displaces the wedge 65 in such directions that the wedge 65 moves into contact with and away from the car guide rail 6. Each of the emergency stop levers 68 is fixed at one end thereof to the interlocking shaft 67. Thus, the respective emergency stop levers 68 are turned around an axis of the interlocking shaft 67 in synchronization with each other. Each of the emergency stop levers 68 is slidably provided at the other end thereof with the wedge 65. When each of the emergency stop levers 68 is turned upward, each wedge 65 thereby breaks into a space between the gripper piece 66 and the car guide rail 6.

[0040] A connection member 69, which is fixed to the link member 62, is turnably connected to an intermediate region of one of the emergency stop levers 68 by means of a pin 70. Thus, each of the emergency stop levers 68 is displaced in such directions that each wedge 65 moves into contact with and away from the car guide rail 6, through the turning of the link member 62. When the link member 62 is turned upward, each of the emergency stop devices 7 is thereby operated. When the link member 62 is turned downward, the operation of each of the emergency stop devices 7 is thereby canceled.

[0041] An elevator control device (not shown) for controlling operation of the elevator is provided within the hoistway 1. The drive device 2 is provided with an encoder (not shown) as a detecting portion for detecting a position and a speed of the car 4. The encoder generates a signal corresponding to rotation of the drive sheave 2a, and transmits the generated signal to the elevator control device. The elevator control device controls operation of the elevator based on information from the encoder.

[0042] Fig. 10 is a graph showing a relationship among the speed of the car 4, the first overspeed, the second overspeed, and the distance from a terminal floor to the car 4 during normal operation of the elevator of Fig. 1. In the figure, the hoistway 1 is provided with acceleration/deceleration sections in which the car 4 is accelerated and decelerated in the vicinity of one terminal floor and the other terminal floor, respectively, and a constant-speed section in which the car 4 moves at a constant speed between the respective acceleration/deceleration sections.

[0043] During normal operation, the speed of the car 4, the first overspeed, and the second overspeed change along a normal speed pattern 71, a first overspeed pattern 72, and a second overspeed pattern 73, respectively, in accordance with changes in the position of the car 4.

[0044] The second overspeed pattern 73 assumes a larger value than the first overspeed pattern 72. The first overspeed pattern 72 assumes a larger value than the normal speed pattern 71. The normal speed pattern 71, the first overspeed pattern 72, and the second overspeed pattern 73 are so set as to remain constant in the constant-speed section and to continuously decrease in each of the acceleration/deceleration sections as the car 4 moves toward each of the terminal floors.

[0045] The normal speed pattern 71 is set in the elevator control device. The elevator control device controls operation of the elevator such that the car 4 is moved within the hoistway 1 along the normal speed pattern 71.

[0046] The operational guide rails 55 are provided within each of the acceleration/deceleration sections. The operational guide rails 55 guide the driven roller 60 such that the first overspeed and the second overspeed continuously decrease as the car 4 moves toward the terminal floor within the acceleration/deceleration section. Thus, the first overspeed changes along the first overspeed pattern 72, and the second overspeed changes along the second overspeed pattern 73.

[0047] Next, an operation will be described. When the car 4 is moved within the constant-speed section, the driven roller 60 is fixed at a predetermined position with respect to the car 4, and the respective magnitudes of the first overspeed and the second overspeed are constant regardless of the position of the car 4.

[0048] When the car 4 is moved toward each of the terminal floors within each of the acceleration/deceleration sections, the driven roller 60 is displaced toward the car guide rails 6 in accordance with the position of the car 4 while being guided by the operational guide rails 55. Thus, the operational arm 57 is turned around the turning shaft 56, and the engaging portion 59 is displaced away from the speed governor sheave 15 in accordance with the displacement amount of the driven roller 60. Thus, the operational member 43 is displaced away from the speed governor sheave 15 with respect to the sheave shaft 14, in accordance with the displacement amount of the engaging portion 59.

[0049] When the operational member 43 is displaced away from the speed governor sheave 15, the adjusting lever 34 is turned in such a direction that the normal position of the flyweight 17 is displaced radially outward, in accordance with the displacement amount of the operational member 43. Thus, the normal position of the flyweight 17 moves toward the stop operation position or the trip position by an amount corresponding to the turning amount of the adjusting lever 34, and the magnitudes of the first overspeed and the second overspeed decrease in accordance with the position of the car 4.

[0050] When the car 4 is moved away from each of the terminal floors within each of the acceleration/deceleration sections, an operation opposite to the above-mentioned one is performed. As a result, the magnitudes of the first overspeed and the second overspeed increase in accordance with the position of the car 4.

[0051] During normal operation, the car 4 is moved within the hoistway 1 along the normal speed pattern 71 through the control by the elevator control device. At this moment, the flyweight 17 receives, owing to rotation of the speed governor sheave 15, such a centrifugal force that the flyweight 17 is not displaced as far as the stop operation position.

[0052] When the speed of the car 4 further rises for some reason and reaches the value of the first overspeed pattern 71, the flyweight 17 is turned to the stop operation position, and the switch lever 22 is operated by the actuating pawl 19. Thus, the drive device 2 is stopped from being supplied with power through the control by the elevator control device. As a result, the brake device is operated to stop the car 4.

[0053] Even when the drive device 2 is stopped in case of, for example, a rupture in the main rope 3, the car 4 is moved without being stopped. When the speed of the car 4 reaches the value of the second overspeed pattern 73, the flyweight 17 is further turned to reach the trip position due to a centrifugal force resulting from rotation of the speed governor sheave 15. Thus, the engaging pawl 26 is disengaged from the trip lever 24, turned, and then engaged with the ratchet 25. Thus, the ratchet 25 is slightly rotated in a rotational direction of the speed governor sheave 15.

[0054] A rotational force of the ratchet 25 is transmitted to the arm 27 via the connection link 30, the spring shaft 29, the spring receiving member 31, and the presser spring 32. Thus, the arm 27 is turned, and the shoe 28 comes into contact with the speed governor rope 10 and then is pressed against the speed governor rope 11 by the presser spring 32. Thus, the speed governor rope 10 is arrested between the speed governor sheave 15 and the shoe 28.

[0055] When the car 4 continues to be lowered while the speed governor rope 10 is arrested, the speed governor rope 10 is thereby pulled downward. As a result, the return pulley 9 is displaced upward with respect to the car 4. Thus, the link member 62 is turned upward with respect to the car 4.

[0056] When the link member 62 is turned upward with respect to the car 4, the respective emergency stop levers 68 fixed to the common interlocking shaft 67 are turned upward simultaneously, and each wedge 65 is displaced upward with respect to the gripper piece 66. Thus, each wedge 65 breaks into the space between the car guide rail 6 and the gripper piece 66, so each of the emergency stop devices 7 is operated. Thus, a breaking force is applied to the car 4, which is then forcibly stopped.

[0057] At the time of recovery, the speed governor rope 10 is stopped from being arrested to raise the car 4, so the respective emergency stop devices 7 are stopped from being operated.

[0058] In the speed governor apparatus for the elevator constructed as described above, the operational guide rails 55, which are inclined with respect to the direction in which the car 4 is moved, are provided within the hoistway 1. The operational arm 57 has the engaging portion 59 and the driven roller 60. The engaging portion 59 is engaged with the operational member 43 in the axial direction of the sheave shaft 14. The driven roller 60, which is coupled to the engaging portion 59, is guided along the operational guide rails 55 through a movement of the car 4. When the driven roller 60 is guided by the operational guide rails 55, the engaging portion 59 is thereby displaced. As a result, the operational member 43 is displaced in the axial direction of the sheave shaft 14, so the magnitudes of the first overspeed and the second overspeed are adjusted. Therefore, even when the speed governor sheave 15 is in rotation, the magnitudes of the first overspeed and the second overspeed can be easily adjusted in accordance with the position of the car 4. The operational member 43 is displaced due to moving energy of the car 4. Therefore, the magnitudes of the first overspeed and the second overspeed can be more reliably adjusted even in case of power outage.

[0059] Accordingly, by adjusting the position at which the operational guide rails 55 are installed and the direction in which the operational guide rails 55 are inclined, the magnitudes of the first overspeed and the second overspeed can be reduced in accordance with a decrease in the distance from each of the terminal floors in each of the acceleration/deceleration sections provided in the vicinity thereof, and can be made constant in the constant-speed section. Therefore, the first overspeed and the second overspeed can be made lower in the vicinity of each of the terminal floors than in the constant-speed section, so the braking distance in stopping the car 4 as an emergency measure can be shortened. Thus, a shock absorber provided in a pit portion of the hoistway 1 can be reduced in size, and the depth dimension of the pit portion can be reduced. An overhead dimension for allowing the car 4 to overshoot or jump can also be reduced. In other words, the dimension of the hoistway 1 in a height direction thereof can be reduced.

[0060] The car 4 is mounted with the return pulley 9 and the pair of the emergency stop devices 7. The return pulley 9, around which the speed governor rope 10 is wound, can be displaced with respect to the car 4. The emergency stop devices 7 are operated through displacement of the return pulley 9 with respect to the car 4. When the speed governor rope 10 is arrested by the braking mechanism 33, the return pulley 9 is thereby displaced with respect to the car 4. Therefore, the operation of the speed governor 8 can be transmitted to the respective emergency stop devices 7 more reliably. In consequence, the respective emergency stop devices 7 can be operated more reliably.

[0061] The interlocking mechanism 46 has the displacement body 47, the sheave shaft-side spline portion 48, and the lever-side spline portion 49. The displacement body 47 is integrated with the operational member 43. The sheave shaft-side spline portion 48, which is provided on the outer peripheral face of the sheave shaft 14, turns the displacement body 47 with respect to the sheave shaft 14 when the displacement body 47 is displaced with respect to the sheave shaft 14. The lever-side spline portion 49, which is provided on the inner peripheral face of the cylinder portion 35a of the adjusting lever 34, turns the cylinder portion 35a with respect to the displacement body 47 in a direction opposite to the direction in which the displacement body 47 is turned by the sheave shaft-side spline portion 48 when the displacement body 47 is displaced with respect to the sheave shaft 14. Therefore, a predetermined resistance force can be generated by the sheave shaft-side spline portion 48 and the lever-side spline portion 49 for displacement of the displacement body 47 in the axial direction of the sheave shaft 14, so the displacement body 47 can be prevented from being shifted in position with respect to the sheave shaft 14 due to a centrifugal force or vibrations resulting from rotation of the speed governor sheave 15.

[0062] The displacement body 47 is spline-coupled to the sheave shaft 14 by the sheave shaft-side spline portion 48, which has the tooth trace inclined with respect to the axial direction of the sheave shaft 14. The displacement body 47 is also spline-coupled to the cylinder portion 35a by the lever-side spline portion 49, which has the tooth trace inclined with respect to the axial direction of the sheave shaft 14. Therefore, owing to displacement of the displacement body 47 in the axial direction of the sheave shaft 14, the displacement body 47 can be turned with respect to the sheave shaft 14 more reliably, and the cylinder portion 35a can be turned with respect to the displacement body 47 more reliably.

[0063] In the foregoing example, the displacement body 47 is spline-coupled to both the cylinder portion 35a and the sheave shaft 14. However, the displacement body 47 may be coupled thereto in any other manner as long as the displacement body 47 can be turned through displacement thereof in the axial direction of the sheave shaft 14.

Embodiment 2

[0064] Fig. 11 is a cross-sectional view showing an essential part of a speed governor apparatus for an elevator according to Embodiment 2 of the present invention. Fig. 12 is a schematic view showing an essential part of the speed governor apparatus as viewed along a radial direction of the speed governor sheave 15 of Fig. 11. In the figures, a slide pin 81, which extends in the radial direction of the speed governor sheave 15, is fixed to the displacement body 47 in a penetrating state. The slide pin 81 has a first protruding portion 81a protruding from the inner peripheral face of the displacement body 47, and a second protruding portion 81b protruding from the outer peripheral face of the displacement body 47.

[0065] A sheave shaft-side groove portion 82, in which the first protruding portion 81a is slidably inserted, is provided in the outer peripheral face of the sheave shaft 14. The sheave shaft-side groove portion 82 is inclined with respect to the axial direction of the sheave shaft 14. The first protruding portion 81a is guided along the sheave shaft-side groove portion 82 through displacement of the displacement body 47 in the axial direction of the sheave shaft 14. Thus, the displacement body 47 is displaced in the axial direction of the sheave shaft 14 while being turned with respect thereto.

[0066] A lever-side groove portion 83, in which the second protruding portion 81b is slidably inserted, is provided in the inner peripheral face of the cylinder portion 35a. The lever-side groove portion 83 is inclined with respect to the axial direction of the sheave shaft 14 in a direction opposite to the direction in which the sheave shaft-side groove portion 82 is inclined. The second protruding portion 81b is guided along the lever-side groove portion 83 through displacement of the displacement body 47 in the axial direction of the sheave shaft 14. The cylinder portion 35a is turned with respect to the displacement body 47 in a direction opposite to the direction in which the displacement body 47 is turned by the sheave shaft-side groove portion 82, through displacement of the displacement body 47 in the axial direction of the sheave shaft 14.

[0067] An angle of inclination of the sheave shaft-side groove portion 82 with respect to the axial direction of the sheave shaft 14 is different from an angle of inclination of the lever-side groove portion 83 with respect to the axial direction of the sheave shaft 14. When the displacement body 47 is displaced with respect to the sheave shaft 14 in the axial direction thereof, the cylinder portion 35a is turned with respect to the displacement body 47 simultaneously with the turning of the displacement body 47 with respect to the sheave shaft 14. The direction in which the displacement body 47 is turned with respect to the sheave shaft 14 is reverse to the direction in which the cylinder portion 35a is turned with respect to the displacement body 47. Accordingly, when the displacement body 47 is displaced in the axial direction of the sheave shaft 14, the adjusting lever 34 is turned with respect to the sheave shaft 14 and the speed governor sheave 15 by a difference between a turning angle of the displacement body 47 with respect to the sheave shaft 14 and a turning angle of the cylinder portion 35a with respect to the displacement body 47.

[0068] An interlocking mechanism 84 for interlocking the operational member 43 and the adjusting lever 34 with each other has the displacement body 47, the slide pin 81, the sheave shaft-side groove portion 82, and the lever-side groove portion 83. Embodiment 2 of the present invention is identical to Embodiment 1 of the present invention in other constructional details.

[0069] In the elevator apparatus constructed as described above, the sheave shaft-side groove portion 82, for guiding the first protruding portion 81a protruding from the inner peripheral face of the displacement body 47 to turn the displacement body 47 with respect to the sheave shaft 14, is provided in the sheave shaft 14, and the lever-side groove portion 83, for guiding the second protruding portion 81b protruding from the outer peripheral face of the displacement body 47 to turn the cylinder portion 35a with respect to the displacement body 47, is provided in the inner peripheral face of the cylinder portion 35a. Therefore, the interlocking mechanism 84 can be simplified in construction, so the cost of production can be reduced.

[0070] Although the sheave shaft-side groove portion 82 is provided in the sheave shaft 14 in the foregoing example, it is possible to replace the sheave shaft-side groove portion 82 with a long hole. Although the lever-side groove portion 83 is provided in the cylinder portion 35a in the foregoing example, it is possible to replace the lever-side groove portion 83 with a long hole.

[0071] In the foregoing respective embodiments of the present invention, the operational guide rails 55 are provided only in each of the acceleration/deceleration sections, and the driven roller 60 is not guided by any rail in the constant-speed section. However, it is also appropriate that parallel guide rails extending parallel to the car guide rails 6 are provided in the constant-speed section, that the driven roller 60 is guided along the operational guide rails 55 when the car 4 is in each of the acceleration/deceleration sections, and that the driven roller 60 is guided along the parallel guide rails when the car 4 is in the constant-speed section.

Claims

1. A speed governor apparatus for an elevator, comprising:

a sheave shaft rotatably supported by a pedestal mounted on a car;

a speed governor sheave designed to be rotatable integrally with the sheave shaft and having wound therearound a speed governor rope stretched vertically within a hoistway, for being rotated in accordance with a movement of the car;

a flyweight provided on the speed governor sheave and designed to be displaceable with respect to the speed governor sheave between a normal position and a trip position that is located radially outward of the speed governor sheave with respect to the normal position, for being displaced from the normal position to the trip position due to a centrifugal force resulting from rotation of the speed governor sheave;

a braking mechanism mounted on the car, for being operated due to displacement of the flyweight to the trip position to arrest the speed governor rope;

an adjusting lever designed to be turnable with respect to the sheave shaft in a circumferential direction of the speed governor sheave, for being turned with respect to the sheave shaft to displace the flyweight and adjust the normal position;

an operational member designed to be displaceable with respect to the sheave shaft in an axial direction of the sheave shaft;

an interlocking mechanism for interlocking the operational member and the adjusting lever with each other to convert displacement of the operational member into a turning movement of the adjusting lever;

a cam member provided within the hoistway and inclined with respect to a direction in which the car is moved; and

an operational force transmitting member having an engaging portion engaged with the operational member in the axial direction of the sheave shaft, and a driven portion coupled to the engaging portion to be guided along the cam member through a movement of the car, for displacing the operational member in the axial direction of the sheave shaft through displacement of the engaging portion resulting from guide of the driven portion by the cam member.

2. A speed governor apparatus for an elevator according to Claim 1, wherein:

the car is mounted with a return pulley having wound therearound the speed governor rope and designed to be displaceable with respect to the car, and an emergency stop device for being operated through displacement of the return pulley with respect to the car to forcibly stop the car from moving; and

the return pulley is displaced with respect to the car through arrest of the speed governor rope by the braking mechanism.

3. A speed governor apparatus for an elevator according to Claim 1 or 2, wherein the interlocking mechanism has an annular displacement body integrated with the operational member, a first guide portion provided on an outer peripheral face of the sheave shaft to turn the displacement body with respect to the sheave shaft when the displacement body is displaced with respect to the sheave shaft, and a second guide portion provided on the adjusting lever to turn a cylinder portion with respect to the displacement body in a direction opposite to a direction in which the displacement body is turned by the first guide portion when the displacement body is displaced with respect to the sheave shaft.

4. A speed governor apparatus for an elevator according to Claim 3, wherein:

at least one of the first guide portion and the second guide portion is designed as a spline portion having a tooth trace inclined with respect to the axial direction of the sheave shaft; and

the displacement body is spline-coupled to at least one of the cylinder portion and the sheave shaft by the spline portion.

5. A speed governor apparatus for an elevator according to Claim 3, wherein:

at least one of the first guide portion and the second guide portion is designed as a groove portion inclined with respect to the axial direction of the sheave shaft; and

the displacement body is provided with a protruding portion inserted in the groove portion.

Drawing