Emergency stop device releasing method for elevator

Abstract: An emergency stop state releasing method for a machine-room-less elevator, which includes a moving cage (2) capable of ascending and descending along a first guide rail (5, 6) in an elevator shaft (1), a counterweight (3) capable of ascending and descending along a second guide rail (7, 8) in the elevator shaft (1), a rope (4) for suspending the moving cage (2) and the counterweight (3), a drive unit (9) in the elevator shaft (1) for driving the rope (4) to move the moving cage (2) up and down in the elevator shaft (1), and an emergency stop mechanism (14) attached to the moving cage (2) and adapted to engage the guide rail (5), thereby emergently stopping the moving cage (2), and to lift the moving cage (2), thereby canceling an emergency stop state, the method comprises steps of, setting a removable winding device (18) in the elevator shaft (1), and driving the moving cage (2) or the counterweight (3) by means of the winding device (18), thereby lifting the moving cage (2) to cancel the emergency stop state.

Description: The present invention relates to an emergency stop releasing method for releasing an emergency stop state of a machine-room-less elevator. With the increase of high-rise buildings, the operating speed of elevators is becoming higher and higher, thus requiring a satisfactory safe measure. A conventional elevator apparatus comprises an elevator shaft, formed extending vertically in a building, and a machine room, which is located right over the shaft and stores a prime mover and the like. This elevator apparatus further comprises a sheave located in the shaft and driven by means of the prime mover, a moving cage disposed in the shaft and connected to one lower end of a rope that is wound on the sheave, and a counterweight connected to the other lower end of the rope and balanced with the cage. The cage is moved up and down by rotating the sheave by means of the prime mover in the machined room. The moving cage and the counterweight are guided by means of guide rails arranged in the elevator shaft. The elevator apparatus of this type is provided with an emergency stop device that can stop the moving cage safely and securely in case the cage suddenly descends at a speed higher than its rated speed for any reason. The emergency stop device brakes and stops the cage in a manner such that wedge members, for example, are driven between the cage and the guide rails. If the emergency stop device is activated, especially when people are confined to the moving cage, the device should be urgently released to rescue the people from the cage. In order to release the emergency stop device of this type, the moving cage must be slightly lifted to allow the wedge members to slip out from between the cage and the guide rails. In the case of conventional elevators, an operator enters the machine room and manually rotates a motor of a drive unit by means of a handle, thereby gradually lifting the moving cage to release the emergency stop device. If the machine room, which stores some devices including the drive unit, control device, etc., is located over the elevator shaft, as mentioned before, however, it projects above the rooftop of the building, for example, possibly resulting in an infringement of the right to sunshine. Recently, therefore, a machine-room-less elevator has become the object of attention in the art. In the elevator of this type, no machine room is located over the elevator shaft, and a small-sized drive unit is provided in a narrow space in the upper or middle part of the shaft, instead. In the case of the elevator having the drive unit arranged in this manner, however, the emergency stop device cannot be released with ease once it is activated. Since the drive unit is located in the narrow space in the elevator shaft, the operator cannot enter the space and manually actuate the drive unit. Thus, it is very difficult to release the emergency stop device. JP 05229766 describes a fixing device for an elevator body. JP 05186159 discloses a method of replacement of an elevator main rope. To stabilize the cage and the balance weight these elements are hung by hanging rope into an elevator shaft (the main rope sagging). A hanger is mounted on the back side of a guide rail. A hanging rope is held in an opening of the hanger. The cage and the balance weight of the elevator are suspended and held by the hanging rope. EP 0 779 233 A2 which forms the preamble of claim 1 refers to a traction sheave elevator. The elevator comprises an elevator car, a counterweight and hoisting ropes supporting the elevator car and the counterweight. The drive machine unit of the elevator with a traction sheave engaging the hoisting ropes is placed in the top part of the elevator shaft. The elevator car and the counterweight travel in the elevator shaft along elevator and counterweight guide rails. A service hatch is provided on the topmost floor opening into the shaft space. A service man can reach the control panel and the machinery through the hatch. Ordinary service operations are to be performed while standing on the top of the elevator car. The service hatch is placed and dimensioned such that the emergency operations stipulated by elevator regulations can be performed with sufficient easy via the hatch. The present invention has been contrived in consideration of these circumstances, and its object is to provide an emergency stop device releasing method for a machine-room-less elevator, whereby an activated emergency stop device can be released quickly to rescue people who are confined to a moving cage, for example. According to the present invention, there is provided an emergency stop state releasing method for a machine-room-less elevator, which includes a moving cage capable of ascending and descending along a first guide rail in an elevator shaft, a counterweight capable of ascending and descending along a second guide rail in the elevator shaft, a rope for suspending the moving cage and the counterweight, a drive unit in the elevator shaft for driving the rope to move the moving cage up and down in the elevator shaft, and an emergency stop mechanism attached to the moving cage and adapted to engage the guide rail, thereby emergently stopping the moving cage, and to lift the moving cage, thereby canceling an emergency stop state. This method comprises steps of setting a removable winding device in the elevator shaft, and driving the moving cage or the counterweight by means of the winding device, thereby lifting the moving cage to cancel the emergency stop state. The method of the invention further comprises steps of removably mounting the winding device on a portion of the guide rail located above the moving cage and lifting the moving cage by means of the winding device. Furthermore, the method of the invention comprises steps of fixing a bracket in any desired position on the guide rail by means of rail clips and mounting the winding device on the bracket. Moreover, the method of the invention comprises steps of removably mounting the winding device on the counterweight and driving the counterweight downward by means of the winding device. Further, the method of the invention comprises steps of removably attaching a bracket to a portion of the guide rail located below the counterweight, setting the winding device between the counterweight and the bracket, and driving the counterweight downward with respect to the bracket by means of the winding device. Preferably, in the method of the invention, a chain block is used as the winding device. This summary of the invention does not necessarily describe all necessary features so that the invention may also be a sub-combination of these described features. This invention can be more fully understood from the following detailed description when taken in conjunction with the accompanying drawings, in which: FIG. 1 is a front view showing a winding device according to a first embodiment of the present invention; FIG. 2A is a side view of a rail clip according to the first embodiment; FIG. 2B is a front view of the rail clip; FIG. 2C is a sectional view taken along line A-A; FIG. 3A is a schematic view showing an outline of an elevator; FIG. 3B is a front view showing a layout of an emergency stop device; FIG. 4 is a front view showing a winding device according to a second embodiment of the invention; FIG. 5A is a side view of a rope gripper according to the second embodiment; . FIG. 5B is a front view of the rope gripper; FIG. 5C is a front view of the rope gripper; FIG. 6 is a front view showing a winding device according to a third embodiment of the invention; FIG. 7 is a front view showing a winding device according to a fourth embodiment of the invention; FIG. 8A is a plan view of a bracket mounting structure according to the fourth embodiment; FIG. 8B is a front view of the bracket mounting structure; and FIGS. 9A and 9B are schematic views showing an emergency stop mechanism. Various embodiments of the present invention will now be described with reference to the accompanying drawings. (First Embodiment) FIGS. 1 to 3B show a first embodiment of the invention, in which FIG. 1 is a front view showing a winding device or a traction machine, FIGS. 2A to 2C are views showing a bracket mounting structure, and FIGS. 3A and 3B are schematic views showing an outline of a machine-room-less elevator. Referring first to FIG. 3A, there will be described the general construction of the elevator. In an elevator shaft 1 provided in a building, a moving cage 2 and a counterweight 3 are suspended and balanced by means of a rope 4. Guide rails 5 and 6 for vertically guiding the moving cage 2 are arranged on the right- and left-hand sides, respectively, of the shaft 1, while counterweight guide rails 7 and 8 for guiding the counterweight 3 for up-and-down motion are arranged behind the left-hand guide rail 6. On the left-hand side of the upper part of the interior of the elevator shaft 1, a drive unit 9 is set in a narrow space between an inner wall of the shaft 1 and a side wall of the moving cage 2. The drive unit 9, which is fixed to the guide rails 6 and 7, can wind up the rope 4, thereby relatively moving the cage 2 and the counterweight 3 up and down. Thus, one end portion of the rope 4, which is wound up by the drive unit 9, is fixed to a rope hitch 10 that is attached to the upper end portion of the guide rail 5, while the other end portion is fixed to a rope hitch 11 that is attached to the upper end portion of the counterweight guide rail 8. The middle portion of the rope 4 is passed around two lower sheaves 12 that are attached to the lower part of the moving cage 2, extends through the drive unit 9, and is then passed around a counterweight sheave 13 that is attached to the upper part of the counterweight 3. Note that, although, in the present embodiment, the two sheaves 12 are arranged along the direction parallel to a surface of a hall-door (not shown) of the elevator, the two sheaves 12 may be arranged along the direction inclined to the surface of the hall-door. As shown in FIG. 3B, emergency stop mechanisms 14 are provided on the bottom portion of the cage 2. The mechanisms 14 serve to stop the moving cage 2 safely and securely in case the cage suddenly descends at a speed higher than its rated speed for any reason. The mechanisms 14 brake and compulsorily stop the cage 2 in a manner such that wedge members, for example, are driven between the cage 2 and the guide rail 6. FIGS. 9A and 9B are enlarged schematic views showing one of the emergency stop mechanisms 14. The moving cage 2 is braked by driving a roller-shaped wedge member 51 between the guide rail 6 and a slope 50 on the cage side, as shown in FIG. 9B. The wedge member 51 is held by means of a holder 52 shown in FIG. 9A as it is moved to the position indicated by dashed line in FIG. 9B. The holder 52 is connected to a governor by means of a mechanism (not shown). If the moving cage 2 descends at a speed higher than a predetermined speed, the holder 52 is pulled up to actuate the emergency stop mechanism 14. In order to cancel an emergency stop state established by the emergency stop mechanism 14, the moving cage 2 must be compulsorily lifted to disengage the wedge member 51. FIG. 1 shows a chain block 18 for use as a winding device, which lifts the moving cage 2 in this manner, thereby releasing the emergency stop mechanism 14. The chain block 18 is suspended by a mounting member 17 that is attached to the guide rail 5 for positioning. As shown in FIGS. 2A to 2C, the mounting member 17 includes a bracket 19, which is wider than the basal part of the guide rail 5 that has a substantially T-shaped cross section. The bracket 19 is bored with a plurality of bolt holes 20, which are arranged longitudinally at intervals a little longer than the width of the rail 5. Nuts 21 are provided on the back surface of the bracket 19, corresponding to the bolt holes 20, individually. Thus, the edge portions of the basal part of the guide rail 5 can be held fixedly by tightening rail clips 22 from the obverse side of the bracket 19. As this is done, an arm 24 can be fastened together to the back side of the bracket 19. As shown in FIG. 2B, a fitting hole 25 is formed in the distal end portion of the arm 24. As shown in FIG. 1, the chain block 18 is suspended from the hole 25 by means of an upper hook 26. A lower hook 28 is provided on one end portion 27a of a chain 27 that is wound around the block 18, and is hitched to an anchor 29 on the ceiling of the moving cage 2. An operator M can pull up the one end portion 27a, to which the lower hook 28 is attached, by holding the other end portion 27b of the chain 27 and endlessly running the chain. Referring now to FIG. 1 and FIGS. 2A to 2c, there will be described a method for releasing the emergency stop mechanism 14, which is a feature of the present invention. When the mechanism 14 is activated so that the moving cage 2 is emergently stopped in the middle of the elevator shaft 1, the operator M gets on the ceiling of the cage 2 from a floor provided with an entrance, carrying the chain block 18 and the mounting member 17 with him. Then, the operator M presses the bracket 19 against the basal part of the guide rail 5 and inserts bolts 23, passed through the rail clips 22, into the bolt holes 20, individually, from the obverse side of the bracket 19. As shown in FIGS. 2A and 2B, the guide rail 5 is an elongate structure formed by tying together a plurality of rails by means of joint plates 31 and bolts 32. Thus, the bracket 19 can be positioned by abutting the lower end face of the bracket 19 against upper end face of one of the joint plates 31. After the bracket 19 is mounted in place, moreover, it can be prevented from shifting its position downward. Then, the chain block 18 is suspended by anchoring its upper hook 26 to the fitting hole 25 in the distal end portion of the arm 24, and the lower hook 28 is hitched to the anchor 29 of the moving cage 2. If the operator M endlessly runs the other end portion 27b of the chain 27 of the chain block 18 in this state, the lower hook 28 is wound up gradually, so that the cage 2 ascends gradually. As the cage 2 ascends in this manner, the emergency stop mechanism 14 is released. Thus, people confined to the moving cage 2, if any, can be rescued speedily. (Second Embodiment) FIGS. 4, 5A, 5B and 5C show a second embodiment of the invention. In FIGS. 1 to 5C, like reference numerals refer to the same components throughout the several views. An elevator according to this embodiment, unlike the one shown in FIG. 3A, is of a type such that a moving cage 2 is suspended by means of a rope 4. In the first embodiment, the lower hook 28 of .the chain block 18 is attached to the anchor 29 that is provided on the ceiling of the moving cage 2. In the present embodiment, however, a rope gripper 33 is mounted on the rope 4 for suspending the moving cage 2, and the lower hook 28 is attached to the gripper 33. As shown in FIGS. 5A to 5C, the rope gripper 33 is composed of two rectangular plate members 34 and 35 having a width greater than that of four rows of the rope 4. Thus, the gripper 33 can hold the four rows of the rope 4. The opposite surfaces of the plate members 34 and 35 are provided with fitting grooves 34a and 35a, respectively, in which the rope 4 is fitted. Further, a plurality of bolts 36 are arranged penetrating those regions of the members 34 and 35 which face the spaces between the rope rows, and nuts 37 are fitted on the bolts 36, individually. A lug 38 protrudes integrally upward from the one plate member 34. A fitting hole 39 is bored through the lug 38. Thus, the rope gripper 33 can be attached to the rope 4 with the four rows of the rope 4 held between the two plate members 34 and 35 and clamped by means of the bolts 3 and the nuts 37. Further, the moving cage 2 can be raised by means of the rope 4 to release the emergency stop mechanism 14 in a manner such that the lower hook 28 of the chain block 18 is anchored to the fitting hole 39 of the gripper 33. According to the present embodiment, the moving cage 2 can be lifted steadily without being tilted, and the rope gripper 33 can be mounted in any desired position on the rope 4. (Third Embodiment) FIG. 6 shows a third embodiment of the invention. In FIGS. 1 to 6, like reference numerals refer to the same components throughout the several views. In the first embodiment, the emergency stop state is canceled by directly hoisting the moving cage 2. In the present embodiment, however, a moving cage 2 is driven by driving a counterweight 3. More specifically, according to this embodiment, a chain block 18 for use as a winding device is attached to a suspension base of a pit 1a of the elevator shaft 1 and a suspension base of the counterweight 3. The moving cage 2 is lifted to release the emergency stop mechanism 14 by lowering the counterweight 3 by means of the chain block 18. A bracket 40 is attached by means of a plurality of bolts 41 to the lower part of the counterweight 3 that is supported by counterweight guide rails 7 and 8 for up-and-down motion. Thus, the bracket 40 can ascend and descend integrally with the counterweight 3. A lug 42 protrudes downward from the crosswise middle portion of the bracket 40. A fitting hole 43 is bored through the lug 42. An upper hook 26 of the chain block 18 is anchored to the fitting hole 43 so that the block 18 is suspended from the hole 43. A lower hook 28 on one end portion 27a of a chain 27 of the chain block 18 is hitched to an anchor 44 in the pit 1a of the elevator shaft 1. The shaft pit 1a is provided with a buffer 45 formed of a coil spring that can absorb the shock of dropping of the counterweight 3. In the case where the moving cage 2 is located near the uppermost floor, it is hard for the operator M to get on its ceiling. With use of the arrangement described above, in this case, the operator M can get into the shaft pit 1a, anchor the upper hook 26 of the chain block 18 to the fitting hole 43 of the bracket 40 to suspend the block 18, and hitch the lower hook 28 to the anchor 44 of the shaft pit la. If the operator M endlessly runs the other end portion 27b of the chain 27 in this state, the one end portion 27a of the chain 27 is wound up gradually, so that the counterweight 3 descends, while the moving cage 2 ascends gradually. As the cage 2 ascends in this manner, the emergency stop mechanism 14 is released. Thus, people confined to the moving cage 2, if any, can be rescued speedily. (Fourth Embodiment) FIGS. 7, 8A and 8B show a fourth embodiment of the invention. In FIGS. 1 to 8B, like reference numerals refer to the same components throughout the several views. According to the present embodiment, a chain block 18 for use as a winding device is attached to a suspension base at the respective lower parts of counterweight guide rails 7 and 8 and a suspension base of a counterweight 3. A moving cage 2 is lifted to release the emergency stop mechanism 14 by lowering the counterweight 3 by means of the chain block 18. A bracket 46 is located corresponding to those portions of the counterweight guide rails 7 and 8 which are located below the counterweight 3. The bracket 46 is attached to the rails 7 and 8 by means of rail clips 22 similar to the ones according to the first embodiment. A fitting hole 47 is bored through the longitudinal middle portion of the bracket 46. An upper hook 26 of the chain block 18 is anchored to a fitting hole 43 of a lug 42 so that the block 18 is suspended from the hole 43. A lower hook 28 on one end portion 27a of a chain 27 of the chain block 18 is hitched to the fitting hole 47 of the bracket 46 that is attached to the counterweight guide rails 7 and 8. In the case where the moving cage 2 is located near the uppermost floor, it is hard for the operator M to get on its ceiling. With use of the arrangement described above, in this case, the operator M can get into a shaft pit 1a, anchor the upper hook 26 of the chain block 18 to the fitting hole 43 of the lug 42 to suspend the block 18, and hitch the lower hook 28 to the fitting hole 47 of the bracket 46. If the operator M endlessly runs the other end portion 27b of the chain 27 in this state, the one end portion 27a of the chain 27 is wound up gradually, so that the counterweight 3 descends, while the moving cage 2 ascends gradually. As the cage 2 ascends in this manner, the emergency stop mechanism 14 is released. Thus, people confined to the moving cage 2, if any, can be rescued speedily. The construction of the chain block 18 in each of the embodiments described herein is given only as an example, and winding devices of various other types may be used in place of the chain block.

Claims: An emergency stop state releasing method for a machine-room-less elevator, which includes a moving cage (2) capable of ascending and descending along a first guide rail (5, 6) in an elevator shaft (1), a counterweight (3) capable of ascending and descending along a second guide rail (7, 8) in the elevator shaft (1), a rope (4) for suspending the moving cage (2) and the counterweight (3), a drive unit (9) in the elevator shaft (1) for driving the rope (4) to move the moving cage (2) up and down in the elevator shaft (1), and an emergency stop mechanism (14) attached to the moving cage (2), the emergency stop mechanism is adapted to engage the guide rail (5) for emergently stopping the moving cage (2) and to cancel an emergency stop state when the moving cage (2) is lifted; characterized in that the method comprises steps of: setting a removable winding device (18) in the elevator shaft (1); and driving the moving cage (2) or the counterweight (3) by means of the winding device (18), thereby lifting the moving cage (2) to cancel the emergency stop state. A method according to claim 1, characterized by further comprising steps of removably mounting the winding device (18) on a portion of the guide rail (5) located above the moving cage (2) and lifting the moving cage (2) by means of the winding device (18). A method according to claim 2, characterized by further comprising steps of fixing a bracket (19) in any desired position on the guide rail (5) by means of rail clips (22) and mounting the winding device (18) on the bracket (19). A method according to claim 1, characterized by further comprising steps of removably mounting the winding device (18) on the counterweight (3) and driving the counterweight (3) downward by means of the winding device (18). A method according to claim 4, characterized by further comprising steps of removably attaching a bracket (19) to a portion of the guide rail (7) located below the counterweight (3) and the bracket (19), and driving the counterweight (3) downward with respect to the bracket (19) by means of the winding device (18). A method according to claim 1, characterized in that a chain block is used as the winding device (18).

Inventors: FUJITA YOSHIAKI, FUJITA, YOSHIAKI, Fujita, Yoshiaki, Intellectual Property Division
Applicants: TOSHIBA KK, KABUSHIKI KAISHA TOSHIBA
Application year: 1999
Main classification: B66B5
IPC codes: B66B5