CA1244783A - Elevator system with improved car leveling - Google Patents
Elevator system with improved car levelingInfo
- Publication number
- CA1244783A CA1244783A CA000487892A CA487892A CA1244783A CA 1244783 A CA1244783 A CA 1244783A CA 000487892 A CA000487892 A CA 000487892A CA 487892 A CA487892 A CA 487892A CA 1244783 A CA1244783 A CA 1244783A
- Authority
- CA
- Canada
- Prior art keywords
- elevator
- car
- motor
- drive
- sheave
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B66—HOISTING; LIFTING; HAULING
- B66B—ELEVATORS; ESCALATORS OR MOVING WALKWAYS
- B66B11/00—Main component parts of lifts in, or associated with, buildings or other structures
- B66B11/04—Driving gear ; Details thereof, e.g. seals
- B66B11/08—Driving gear ; Details thereof, e.g. seals with hoisting rope or cable operated by frictional engagement with a winding drum or sheave
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B66—HOISTING; LIFTING; HAULING
- B66B—ELEVATORS; ESCALATORS OR MOVING WALKWAYS
- B66B1/00—Control systems of elevators in general
- B66B1/34—Details, e.g. call counting devices, data transmission from car to control system, devices giving information to the control system
- B66B1/36—Means for stopping the cars, cages, or skips at predetermined levels
- B66B1/40—Means for stopping the cars, cages, or skips at predetermined levels and for correct levelling at landings
- B66B1/42—Means for stopping the cars, cages, or skips at predetermined levels and for correct levelling at landings separate from the main drive
Landscapes
- Engineering & Computer Science (AREA)
- Automation & Control Theory (AREA)
- Computer Networks & Wireless Communication (AREA)
- Civil Engineering (AREA)
- Mechanical Engineering (AREA)
- Structural Engineering (AREA)
- Cage And Drive Apparatuses For Elevators (AREA)
- Elevator Control (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
An elevator drive sheave, from which the car is suspended, has a drive shaft rotatably supported by a frame member. The main hoist motor is coupled to the drive shaft directly or through gears, and a linear actuator is connected between the hoist motor and frame. The linear actuator coupler absorbs reaction rotational torque of the motor and also can selectively pivot the motor and thereby the drive sheave about the sheave axis or another axis while the hoist motor brake is engaged. As a result, the car may be re-positioned while stopped at a landing without using the hoist motor.
An elevator drive sheave, from which the car is suspended, has a drive shaft rotatably supported by a frame member. The main hoist motor is coupled to the drive shaft directly or through gears, and a linear actuator is connected between the hoist motor and frame. The linear actuator coupler absorbs reaction rotational torque of the motor and also can selectively pivot the motor and thereby the drive sheave about the sheave axis or another axis while the hoist motor brake is engaged. As a result, the car may be re-positioned while stopped at a landing without using the hoist motor.
Description
SPECIFICATION
BACKGROUND OF THÉ INVENTION
The present invention is a device for leveling an elevator car, in particular for re-leveling the car while at the lan~ing with the doors open.
In a conventional traction-t~rpe elevator system, the main hoist motor is controlled so as to stop a moving elevator car at a desired floor so as to be level with the landing sill. When positioned, the main hoist motor is stopped, and the elevator brake is engaged to hold the car in position while the elevator doors are open.
Although the elevator control is normally adjusted to stop the car level on its original approach to the landing, misadjustment, wear, temperature, etc. can cause variations in leveling accuracy. Even if the car is stopped level, it is common for the elevator car to move relative to the landing sill while the doors are open. This occurs due to the fact that the elevator cables are resilient and the fact that the weight of the car changes as passengers enter and leave. For such reasons, it is sometimes necessary to re-level the elevator car with the doors open.
1 62~
~.~4~7~33 It is a common practic~ to utilize the main hoist motor to correct errors in the level of the elevator car. In the event re-leveling is required and the elevator car is stopped at the landing, the holding brake is released, and the main hoist motor is actuated by bypassing the hoistway door interlocks and the car gate switch, which normally disable the motor. However, it is difficult to carry out this procedure without producing undesired car movement. While the car is stopped, the holding brake supports the net unbalance in the system. The release of the brake must therefore be coordinated preciseiy with the energization of the motor so that the motor has developed sufficient torque to support this unbalance as the brake releases. Correspondingly, to avoid a jerking motion, the brake should not remain engaged toc- long after the main hoist motor is actuated.
In addition to the difficulty of synchronizing the release of the brake with the actuation of the motor, the controls for effecting simultaneous motor/bra~e-release operation are subject to misadjustment orvariation over time. As a result, during the initiation of re-leveling operations, it is possible that the car may be permitted to move further away from the level of the landing sill before actual correction occurs. This is obviously undesirable since, during this time, people may be enteri~g or leaving the car.
Some prior art elevator systems have attempted to pre-torque the hoist motor before releasing the brake by sensing the load in the car. This method is inadequate ~:44~7~33 since the load in the car is only one of the condltions contributing to the unbalance. In an uncompensated system, the weight of the hoist ropes can change the unbalance depending on the vertical position of the car in the hatchway. Traveling cables also contribute to the unbalance, depending on car position.
In addition to the difficulty of transmitting smoothly the weight-holding function from the brake to the motor, another shortcoming of these known systems lies in the fact that the equipment used to accomplish this task is designed to move the car large distances, at high speeds. However, the intent of the leveling action is to move the car only incremental distances, at low speed. This further complicates the re-leveling procedure, and a control malfunction could cause the car to move abruptly.
In place o~ using the main hoist motor for re-leveling, it has been proposed to interpose a linear actuator between the elevator sling and the hitch plate to which the hoist ropes are fastened. A motor, positioned in the top of the elevator.car, actuates the linear actuator to move the sling up or down relative to the hoist ropes, without using the main hoisting machine.
Such a system has disadvantages. The auxiliary motor must lift both the car ànd all equipment supported by the car as well as the live load. No part of this load is counter-weighted as far a the auxiliary hoist is concerned and, therefore, a relatively large auxiliary motor needs to be mounted on the car. In addition, power for this auxiliary hoist motor must be carried through ~Z~4783 traveling cables, and it is difficult to make an auxiliary hoist motor on the car that is sufficiently quiet.
Movement of the elevator car away from the landing is detected by leveling transducers, normally mounted on the elevator sling; or the car level may be controlled by a selector mechanism, having a selector cable fastened to the elevator sling. In either case, the indicia of car position used is the position of the sling. However, the cab floor can move with respect to the sling due to compression o~ rubber or deflection of other parts. Use of the conventionally mounted leveling transducer or the selector to position the sling may result in the cab platform being some distance from the landing sill.
SUMMARY OF THE INVENTION
The present invention is a traction elevator having an improved leveling system, whereby the height of the elevator car may be adjusted without releasing the brake or energizing the main hoist motor.
More particularly, in accordance with the present invention, the main traction sheave in the penthouse and driving motor are supported so that the sheave may be turned about its own center or about some other pivot in order to move the car and counterweight while the hoist motor brake is engaged.
An elevator car is suspended by cables in a hoistway and vertically displaceable between landings.
The cables pass over a drive sheave supported by a frame portion in the penthouse. A main motor is coupled, either ~Z4~7~33 directly or through gearing, to the drive shaft of the drive sheave for rotating the drive sheave for raising and lowering the car, and a brake is selectively engageable to stop the motor and drive shaft for holding the car at a selected landing. An auxiliary drive is connected between the motor and frame for selectively pivoting the motor about an axis parallel to or concentric with the drive sheave axis while the brake is engaged. Since, when the braXe is engaged, the motor and drive sheave are locked relative to one another, rotation of the motor correspondingly rotates the drive sheave about a pivot axis, either its own or another axis, raising or lowering the position of the elevator car.
In a preferred embodiment, the drive shaft is`
15 ~ mounted in bearings on the frame. The main hoIst motor is connected through a gear reducer to the drive shaft, and the gear reducer housing is connected to the frame through a screw type linear actuator. When the actuator is stationary, the connection absorbs the reaction torque of the motor so that the motor can drive the sheave. When the actuator is actuated, the main hoist motor housing is caused to move relative to the frame, such that it pivots about the axis of the drive sheave. This motion rotates the drive sheave and raises or lowers the hoist ropes connecting the car a pre-selected amount. Preferably, a pair of stops are provided to limit the degree of motion permitted of the housing. Also preferably, a pair of switches are provided to sense the center position of ~:447~33 the housing, and a control means is provided to return the housing to the center position as the car moves between floors.
The invention may be utilized in arrangements both where the cable passes over a single drive sheave, and where an idler sheave is used. In the latter caSe, it may be preferable to support the linear actuator overhead of the drive and idler sheaves. In each case, the shaft of the linear actuator is arranged to engage 10. the housing at an angle tangent to the pivot axis, which in this case is the axis of rotation of the sheave.
In an alternative arrangement, the drive shaft is supported by the frame on a member pivotable relative to the frame. This pivot axis is spaced from the rotational lS axls of the drive shsave. Both the maln hoist` motor and drivs~shaft are pivotable by a linear actuator arranged bstween~ths pivoting member and the frame. An idler sheave is provided such that the drive and idler sheaves ;~ are located on opposite sides of the second pivot, in ~20 a "seesaw" type of structure.
Preferably, leveling transducers are mounted on the elevator cab, and actuating cams or vanes are positioned at each of the floors. The car is stopped at selected floors by these leveling transducers. These leveling transducers are then utiIized to actuate the linear actuators so as to complete the leveling process, if the car is slightly misadjustedr and also to re-level the car during the time the elevator doors are opened.
~;~447~3 When the elevator car doors are again closed, and the elevator is traveling between floors, the linear actuator is energized to return the main hoist motor housing to its center position so that upon arriving at the next floor, it can be moved in either direction to raise or lower the car as required.
Preferably, means are also provided to produce an analog signal indicative of the magnitude and direction of the weight unbalance in the system without regard to the cause of the unbalance. This analog signal may be used to pre-torque the hoist motor to cancel the efect of the unbalance before releasing the brake.
The torque arm connection is an ideal place to measure this static unbalance. In one embodiment, 15 ~ a pressure transducer is used with a hydraulic actuator.
Alternatively, a strain gauge is used with a mechanical :
actuator. Based on this transducer output, the motor torque is set before the brake is released.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a front, schematic view of an elevator having an improved leveling system in accordance with the invention;
Figs. 2 and 3 are front and side views, respectively, of an embodiment of a leveling system in accordance with the invention;
Fig. 3~ is a side view of a leveling system similar to Figs. 2-3, as used with a belt-driven gear reducer;
~Z447~33 Figs. 4 and 5 are front and side views, respectively, of a second embodiment of a leveling system;
Figs. 6 and 7 are front and side views, respectively, of a third embodiment of the invention;
Fig. 8 is a side view of a fourth embodiment of the invention; and Fig. 9 is a schematic circuit diagram of a control system for the elevator leveling systems shown in Figs.
1-8.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to Fig. 1, an elevator has a car 10 which includes a cab 12 supported within a sling 14. The car 10 is suspended from cables 16 which are wrapped over 15 a drive sheave 18 and extent around an idler sheave 20 to counterweights 22. The car is vertically displaceable between landings in a hoistway in a conventional manner.
The drive sheave 18 has a drive shaft 24 rotatably supportedl by bearings 26, on a frame portion 28 in the pe~nthouse of the elevator. A main hoist motor 30 is coupled, either directly or through intermediate gears, to the drive shaft 24, and a coupler 32, which is indicated only schematically, is connected between the motor 30 and frame 28 for absorbing reaction torque. As discussed below, the coupler 32 includes a linear actuator or other such device.
24~L7~33 In Fig. 1, the car 10 is stopped at a landing L so that the platform 12a of cab 12 is level with the landing sill S. A positionin~ indicator 15, e.g. a transducer, is mounted on the platform 12a, and registers with an actuating device 17, e.g. a cam or vane, attached at a fixed position on the hoistway wall H, for indicating the position of the pLatform 12a relative to the landing sill S. Leveling transducers and the like Lor indicating relative position, are well known. Alternatively, the actuating cam or vane may be mounted on the elevator guide rails (not shown).
Figs. 2-3 show a first arrangement in which the drive shaft 24 of the drive sheave 18 is mounted for rotation on the frame 28a in a pair of spaced bearing 15 ~ blocks 27. The drlve sheave 18 is connected to a conventional gear reducer 34, which in turn engages the cutput shaft of a main hoist motor 30. The gear reducer may be a so-called "hollow output shaft" gear reducer, and is "hung' on an extension of the sheave drive shaft. The motor 30 is flange mounted to the gear box of the reducer 34.
A disk brake 36 (Fig. 3, 3a~ on the hoist motor output shaft may be selectively engaged to lock the main hoist motor 30, and thereby the drive shaft 24, from rotating.
Since the main hoist motor and reduction gear box are hung from the shaft 24, the gear box must have a torque arm connection, i.e. coupler 32 as shown diagram-matically in Fig. 1, to produce the reaction to its output 47~33 torque. In Figs. 2-3, this torque arm connection includes a motor-driven linear actuator, which comprises an auxiliary motor 37, pivotally connected at 41 to the frame, driving an output screw 38. The screw 38 is threaded through a nut 39 retained by a yoke shaped torque arm flange 40 of the gear box housing 34, such that rotation of the screw 38 by motor 30 causes the flange 40 to move linearly back and forth along the screw axis. Preferably the ~ut 39 is pivotable in the yoke 40, as indicated at 43, the pivotable connections of the nut 39 and motor 37 permltting the yoke 40 to move back and forth without binding.
As can be seen, when the flange 40 is displaced by the screw 30, the entire gear box housing and shaft 24, which are locked together as a unit when the brake 36 is engaged, rotate about the axis of shaft 24, thereby rotating the drive sheave 18. As such, the cables 16 and elevator car 10 can be moved a limited amount for re-leveling without releasing the braXe or energizing the hoist motor.
A pair of mechanical end stops 42 are provided at either end of the travel of flange 40 to limit the extent by which the motor/gear box unit can pivot and also to engage the gear box in the event of a failure of the screw 38 or nut 39. In addition, as shown, a pair of switches 44, 45 and a centering cam 46 may be pro~ided as an indication of the center position of the flange 40.
r:
.
-10- :
.
-~2~47B3 .
Fig. 3a is similar to Figs. 2-3, except ~hat the output shaft of motor 30 is coupled to the gear reducer 34 through a pulley/belt arrangement 34a, rather than being connected directly to the input shaft of the reducer 34. The mechanical stops and centering switches have been omitted for-clarity. In Fig. 3a, gear reducer 34 is upside down, as compared with Fig. 3, and motor 30 is fixed to the upper portion of the housing for clearance.
Also, yoke flange 4Q extends from the end of the reducer housing opposite that in Fig. 3, but in operation the leveling mechanisms of Figs. 2-3 and 3a are equivalent.
In the embodiment shown in Figs. 4-5, the drive shaft 24 of the drive sheave 18 is supported in bearing blocks 26b on a pair of spaced channels 48 of the frame.
The linear actuator motor 37 is pivotally mounted at pivot 50 to a portion of the frame 28b so as to be overhead of the drive sheave 18. An idler sheave 20b is also mounted in bearing blocks 52 on the channel members 48 so that the ropes 16 pass over the drive sheave 18 and idler sheave to the car 10 and counterweights 22, respectively. The hoist ropes are double-wrapped for added traction.
The gear reducer 34 extends vertically up from the shat 24 so that the motor 30 and torque arm flange 40 are overhead to engage the screw portion 38 of the linear actuator shaft. As in the Figs. 2-3 embodiment, the screw 38 engages the fl~nge 40 at an angle tangent to the axis of rotation of the gear box housing about shaft 24.
~Z~47~33 Figs. 6-7 illustrate an embodiment of the invention in which the drive shaft 24 of the sheave 18 is pivotably supported by the frame. A pair of support channels ~0 are pivotably supported between frame members 62, and rotatably support the shafts of the drive sheave 18 and idler sheave 20d on opposite sides of the pivot. The output shaft of the main hoist motor 30, through a solidly mounted gear reducer 34, is connected to the drive shaft 24 of the drive sheave 18. A linear actuator 32 is attached between the channels 60 and the fixed portion of the frame 28d, so that the channels, sheaves, and main hoist motor may be pivoted about the pivot axis. A pair of end stops 42a are provided, which limit the angle of pivot of the channels 60 provided by the screw 38/nut 39 combination.
Although not shown, centering switches may be provided in a manner similar to the other embodiments. As shown, the ropes are double wrapped around the drive and idler sheaves for greater traction. t Fig. 8 illustrates a leveling mechanism used with a gearless elevator drive. A DC motor 30' has an output drive shaft 24' supported in bearings in a pair of spaced pedestals 27', forming part of frame 28'. Drive sheave 18' is mounted directly on the output shaft 24'.
A torque-arm connection, in the form of linear actuator 37, 38 engaging a nut 39` pivotably mounted to ,-the motor housing, absorbs rotational torque when the motor is running. The linear actuator is also capable i;
of selectively pivoting the motor 30' and drive sheave ~Z447~3:3 18' about sheave axis 24' when the motor is stoppe`d and disc brake 36' is engaged. End stops 42' may be provided on either side of the motor (one pair is shown), between the motor and frame, to limit rotational movement.
S A strain gauge 90 is positioned on linear actuator 37, 38,-to provide an indication of the instantaneous imbalance in the system. Alternatively, a pressure transducer or the like may be employed. The load signal may be used as an input to known control systems for starting a stopped car, which pre-torque the main hoist motor to compensate for imbalance, prior to releasing the brake.
As discussed above, imbalance results from a number of factors. Unlike the known inputs to such compensating systems, typically weight sensors attached to the car, the sensor 90 provides a true indication of system imbalance acting on the main drive sheave, without regard to the source of that imbalance.
In Fig. 8, the motor shaft 24', which is also ~0 the drive shaft for drive sheave 18', extends from either end of the motor housing to be supported in bearing blocks.
Alternative support configurations are possible. ~or ; example, one end of the shaft may be supported in a bearing in the end bell 31' portion of the motor housing. This bearing may then extend into a bearing into the pedestal block.
In operation, once the car is at the landing, the main hoist motor is stopped and the elevator brake engages. While the car is at the landing, the net load of the car, and the amount of elongation in the hoist ~L2~47~33 ropes, may change as passengers enter and leave. If the elevator cah moves away from the landing sill S by greater than a predetermined distance, the auxiliary motor 37 is actuated to either raise or lower the car.
A loaded elevator, arrivlng at a lobby of a fairly tall building, might have to re-level several times as the passengers exit the elevator. In the system in accordance with the invention, the cab platform may b,é
maintained very close to the level of the landing since corrections as small as 1/16" can easily be made. It is almost impossible to release the brake and move the main hoist machine such a small distance, or as quickly and as smoothly as the present invention.
If desired, the present invent1on may be utilized for final positioning of the car at the landing sill when the elevator is arriving. Accordingly, the main hoist motor may be used to move the cab to approximately the position of the sill, and thereafter the auxiliary positioning system may be actuated for final leveling.
~o However, as discussed above, even elevator systems in which the main hoist motor initially positions the cab with sufficient accuracy have the need for the re-leveling feature when the doors are open.
Fig. 9 is a diagram of an illustrative control circuit for adjusting the position of the car relative to the landing sills. A conventional circuit for actuating the main hoist motor includes a pair of relays 110, 112, which enerize the main hoist motor for the up and down ~2447~33 directions, respectively, and a relay 114 which when actuated releases the holding brake. The hoist up relay 110, when actuated, also opens "up" switch 116, and closes "up" switch 118. The down relay 112, when actuated opens "down" switch 120 and closes "down'i swi.ch 122. A door interlock switch 128 is also provided, which interrupts the main hoist motor actuating circuit when the doors are open, so that the elevator car cannot be moved by the main hoist motor.
The element 200 is a switch (relay contact) that is opened as the car begins a high speed run, and closes, during slowdown, as the car approaches the target floor. For stopping the moving elevator car, a pair of leveling switches, a "platform level up" switch 130, and a "platform level down" switch 132, are provided. Switches 130, 132 are part of positioning indicator 1~ (see Fig.
1). When the sling and cab of the moving elevator reach a landing~ depending upon the direction of car movement, switch 130 or 132 will be closed to actuate a sling level up relay 134 or a sling level down relay 136. The relays 134, 136 open the sling level up switch 138 and sling level down switch 140, respectively, to open the energizing circuit of the actuated relay 110 or 112, and stop the main hoist motor.
An "up run" switch 124 and "down run" switch 126 are also provided. The switches 124 and 126 are used for re-starting a stopped elevator once the doors are again closed. As shown, the switches 124, 126 by-pass`
the switches 118, 12?, 138 and 140 so that, once the doors .
~;~44783 close (re-closing switch 128), the relay 110 or 112 may be actuated, to re-start the elevator, regardless of the position of the other switches. Switches 124, 126 should open about the time that the door zonè is energized so that switches 138 and 140 have control of the stopping of the elevator.- Finally, a door zone switch 142 ~see also Fig. 1) is normally connected to be closed when the sling is in position near the sill to actuate a door zone relay 144 to allow power door operation.
The switch 200 prevents the "Level Up", `'Level Down", and "Door Zone" relays from operating as the car leaves a landing, or is running past landings at high speed, or during the initial part of the deceleration if the slowdown ~istance is greater than one floor. It is closed while a car is stopped.
A pair of oppositely acting "run" switches 174, 176 are arranged in series with the switches 150, 152 and switches 44 r 45, whose function is described below~
When the car is stationary, switch 174 is closed and switch 176 is open. While the car is moving, switch 174 is open and switch 176 is closed. Accordingly, only one of the parallel circuits, that containing switches 150, 152 or that containing switches 44, 45,is active at one time.
As noted above, "platform level up" switch 130 2S and `'platfo~m level down" switch 132 are mounted to be actuated when the elevator car is not level with the sill.
These switches, through relays 134, 136, are used to stop the moving car level with the sill.
47~33 Relays 134, 136 also actuate switches 150, 152.
The circuit containing switches 150 and 152 is inoperative while the car is moving (switch 174 is open), and thus in this embodiment switches 150, 152 do not affect the stopping procedure. But, when the main hoist motor is stopped, i.e.
when the switch 174 is closed, and the car is stopped at the landing, the circuit containing switches 150, 152 is active. Closing of switch 150 or 152, which occurs when one of the switches`l30, 132 is closed (indicating the car is not level), will re-level the car as described below.
In the position of the switches shown, the car is stopped at the landing, and switch 174 is closed. The platform either had been stopped by the main hoist motor below the level of the sill, or has since moved down relative -to the sill. As a-resuIt, the "platform ievel up" switch r 130 has been closed. Closing of switch 130 energizes relay 134 to close switch 150. A corresponding result .
occurs if the car is too high, actuating switch 132, to cause switch 152 to close. `
The switches 150, 152 selectively actuate a .
"platform level up relay" 154 or a "platform level down relay" 156. Actuation of either of the relays 154, 156 `i closes an appropriate switch to energize the auxiliary ; motor 37, to actuate the linear actuator and cause the car to move up or down. The relays 154, 156 are shown r;',' schematically as being connected to a triple switch 160, !~
for reversing the direction of rotation of the motor 37; ,r-~
however, any appropriate arrangement may be used.
47~3 In view of the direct electrical positioning control effected by this arrangement, a transducer or switches 150, 152, or other such position indicator may be directly mounted on the cab, so that the level of the cab is accurately measured and precisely controlled.
When the elevator car is repositioned, the torque arm 40 or 40a (Figs. 6-7) moves relative to the screw 38, that is, the linear actuator is no longer at its center position, which causes one of the switches 44, 45 to close.
As shown the switches 44, 45 are arranged in parallel relative to the corresponding switches 150, 152 and while the car is stopped, switch 176 is open, so that switches 44, 45 do not interfere with the leveling function of switches 15Q, 152. -`
.
As soon as~the car moves away from the landing toward the next floor, switch 174 is opened, disabling the circuit containing switches 150, 152, and switch 176 is closed. At such time, if the linear actuator is out of center position, the actuator centering switches 44, ~5 energize the appropriate relay 154 or 156 to cause motor 37 to re-center the tor~ue arm.
Switch 176 should be closed responsive to movement of the car between landings. Closing of switch 176 may ~e responsive to energization of the main hoist motor. -Alternatively, the closing of switch 176 can be velocity responsive. In this case, the closing of switch 176 should be delayed until the car velocity is appreciably greater -18- ~
~lZ~4q~33 than that produced by the linear~actuator so as to "mask"
the velocity change produced by the linear actuator during the centering operation.
The foregoing represent preferred embodiments of the invention. Variations and modifications of the embodiments shown will be apparent to persons skilled in the art without departing from the inventive concepts disclosed herein. For example, the drive arrangement in the Figs. 2-7 embodiments may also be gearless. Also, }O while a screw-type linear actuator has been shown, such is only illustrative and any suitable adjustment mechanism or device, hydraulic, electrical, or mechanical, which is capable of taking up the counter-torque of the m~tor and of selectively pivoting the motor and sheave drive shaft may be employed. All such modifications and variations are intended to be within the scope of the present invention as defined in the following claims.
BACKGROUND OF THÉ INVENTION
The present invention is a device for leveling an elevator car, in particular for re-leveling the car while at the lan~ing with the doors open.
In a conventional traction-t~rpe elevator system, the main hoist motor is controlled so as to stop a moving elevator car at a desired floor so as to be level with the landing sill. When positioned, the main hoist motor is stopped, and the elevator brake is engaged to hold the car in position while the elevator doors are open.
Although the elevator control is normally adjusted to stop the car level on its original approach to the landing, misadjustment, wear, temperature, etc. can cause variations in leveling accuracy. Even if the car is stopped level, it is common for the elevator car to move relative to the landing sill while the doors are open. This occurs due to the fact that the elevator cables are resilient and the fact that the weight of the car changes as passengers enter and leave. For such reasons, it is sometimes necessary to re-level the elevator car with the doors open.
1 62~
~.~4~7~33 It is a common practic~ to utilize the main hoist motor to correct errors in the level of the elevator car. In the event re-leveling is required and the elevator car is stopped at the landing, the holding brake is released, and the main hoist motor is actuated by bypassing the hoistway door interlocks and the car gate switch, which normally disable the motor. However, it is difficult to carry out this procedure without producing undesired car movement. While the car is stopped, the holding brake supports the net unbalance in the system. The release of the brake must therefore be coordinated preciseiy with the energization of the motor so that the motor has developed sufficient torque to support this unbalance as the brake releases. Correspondingly, to avoid a jerking motion, the brake should not remain engaged toc- long after the main hoist motor is actuated.
In addition to the difficulty of synchronizing the release of the brake with the actuation of the motor, the controls for effecting simultaneous motor/bra~e-release operation are subject to misadjustment orvariation over time. As a result, during the initiation of re-leveling operations, it is possible that the car may be permitted to move further away from the level of the landing sill before actual correction occurs. This is obviously undesirable since, during this time, people may be enteri~g or leaving the car.
Some prior art elevator systems have attempted to pre-torque the hoist motor before releasing the brake by sensing the load in the car. This method is inadequate ~:44~7~33 since the load in the car is only one of the condltions contributing to the unbalance. In an uncompensated system, the weight of the hoist ropes can change the unbalance depending on the vertical position of the car in the hatchway. Traveling cables also contribute to the unbalance, depending on car position.
In addition to the difficulty of transmitting smoothly the weight-holding function from the brake to the motor, another shortcoming of these known systems lies in the fact that the equipment used to accomplish this task is designed to move the car large distances, at high speeds. However, the intent of the leveling action is to move the car only incremental distances, at low speed. This further complicates the re-leveling procedure, and a control malfunction could cause the car to move abruptly.
In place o~ using the main hoist motor for re-leveling, it has been proposed to interpose a linear actuator between the elevator sling and the hitch plate to which the hoist ropes are fastened. A motor, positioned in the top of the elevator.car, actuates the linear actuator to move the sling up or down relative to the hoist ropes, without using the main hoisting machine.
Such a system has disadvantages. The auxiliary motor must lift both the car ànd all equipment supported by the car as well as the live load. No part of this load is counter-weighted as far a the auxiliary hoist is concerned and, therefore, a relatively large auxiliary motor needs to be mounted on the car. In addition, power for this auxiliary hoist motor must be carried through ~Z~4783 traveling cables, and it is difficult to make an auxiliary hoist motor on the car that is sufficiently quiet.
Movement of the elevator car away from the landing is detected by leveling transducers, normally mounted on the elevator sling; or the car level may be controlled by a selector mechanism, having a selector cable fastened to the elevator sling. In either case, the indicia of car position used is the position of the sling. However, the cab floor can move with respect to the sling due to compression o~ rubber or deflection of other parts. Use of the conventionally mounted leveling transducer or the selector to position the sling may result in the cab platform being some distance from the landing sill.
SUMMARY OF THE INVENTION
The present invention is a traction elevator having an improved leveling system, whereby the height of the elevator car may be adjusted without releasing the brake or energizing the main hoist motor.
More particularly, in accordance with the present invention, the main traction sheave in the penthouse and driving motor are supported so that the sheave may be turned about its own center or about some other pivot in order to move the car and counterweight while the hoist motor brake is engaged.
An elevator car is suspended by cables in a hoistway and vertically displaceable between landings.
The cables pass over a drive sheave supported by a frame portion in the penthouse. A main motor is coupled, either ~Z4~7~33 directly or through gearing, to the drive shaft of the drive sheave for rotating the drive sheave for raising and lowering the car, and a brake is selectively engageable to stop the motor and drive shaft for holding the car at a selected landing. An auxiliary drive is connected between the motor and frame for selectively pivoting the motor about an axis parallel to or concentric with the drive sheave axis while the brake is engaged. Since, when the braXe is engaged, the motor and drive sheave are locked relative to one another, rotation of the motor correspondingly rotates the drive sheave about a pivot axis, either its own or another axis, raising or lowering the position of the elevator car.
In a preferred embodiment, the drive shaft is`
15 ~ mounted in bearings on the frame. The main hoIst motor is connected through a gear reducer to the drive shaft, and the gear reducer housing is connected to the frame through a screw type linear actuator. When the actuator is stationary, the connection absorbs the reaction torque of the motor so that the motor can drive the sheave. When the actuator is actuated, the main hoist motor housing is caused to move relative to the frame, such that it pivots about the axis of the drive sheave. This motion rotates the drive sheave and raises or lowers the hoist ropes connecting the car a pre-selected amount. Preferably, a pair of stops are provided to limit the degree of motion permitted of the housing. Also preferably, a pair of switches are provided to sense the center position of ~:447~33 the housing, and a control means is provided to return the housing to the center position as the car moves between floors.
The invention may be utilized in arrangements both where the cable passes over a single drive sheave, and where an idler sheave is used. In the latter caSe, it may be preferable to support the linear actuator overhead of the drive and idler sheaves. In each case, the shaft of the linear actuator is arranged to engage 10. the housing at an angle tangent to the pivot axis, which in this case is the axis of rotation of the sheave.
In an alternative arrangement, the drive shaft is supported by the frame on a member pivotable relative to the frame. This pivot axis is spaced from the rotational lS axls of the drive shsave. Both the maln hoist` motor and drivs~shaft are pivotable by a linear actuator arranged bstween~ths pivoting member and the frame. An idler sheave is provided such that the drive and idler sheaves ;~ are located on opposite sides of the second pivot, in ~20 a "seesaw" type of structure.
Preferably, leveling transducers are mounted on the elevator cab, and actuating cams or vanes are positioned at each of the floors. The car is stopped at selected floors by these leveling transducers. These leveling transducers are then utiIized to actuate the linear actuators so as to complete the leveling process, if the car is slightly misadjustedr and also to re-level the car during the time the elevator doors are opened.
~;~447~3 When the elevator car doors are again closed, and the elevator is traveling between floors, the linear actuator is energized to return the main hoist motor housing to its center position so that upon arriving at the next floor, it can be moved in either direction to raise or lower the car as required.
Preferably, means are also provided to produce an analog signal indicative of the magnitude and direction of the weight unbalance in the system without regard to the cause of the unbalance. This analog signal may be used to pre-torque the hoist motor to cancel the efect of the unbalance before releasing the brake.
The torque arm connection is an ideal place to measure this static unbalance. In one embodiment, 15 ~ a pressure transducer is used with a hydraulic actuator.
Alternatively, a strain gauge is used with a mechanical :
actuator. Based on this transducer output, the motor torque is set before the brake is released.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a front, schematic view of an elevator having an improved leveling system in accordance with the invention;
Figs. 2 and 3 are front and side views, respectively, of an embodiment of a leveling system in accordance with the invention;
Fig. 3~ is a side view of a leveling system similar to Figs. 2-3, as used with a belt-driven gear reducer;
~Z447~33 Figs. 4 and 5 are front and side views, respectively, of a second embodiment of a leveling system;
Figs. 6 and 7 are front and side views, respectively, of a third embodiment of the invention;
Fig. 8 is a side view of a fourth embodiment of the invention; and Fig. 9 is a schematic circuit diagram of a control system for the elevator leveling systems shown in Figs.
1-8.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to Fig. 1, an elevator has a car 10 which includes a cab 12 supported within a sling 14. The car 10 is suspended from cables 16 which are wrapped over 15 a drive sheave 18 and extent around an idler sheave 20 to counterweights 22. The car is vertically displaceable between landings in a hoistway in a conventional manner.
The drive sheave 18 has a drive shaft 24 rotatably supportedl by bearings 26, on a frame portion 28 in the pe~nthouse of the elevator. A main hoist motor 30 is coupled, either directly or through intermediate gears, to the drive shaft 24, and a coupler 32, which is indicated only schematically, is connected between the motor 30 and frame 28 for absorbing reaction torque. As discussed below, the coupler 32 includes a linear actuator or other such device.
24~L7~33 In Fig. 1, the car 10 is stopped at a landing L so that the platform 12a of cab 12 is level with the landing sill S. A positionin~ indicator 15, e.g. a transducer, is mounted on the platform 12a, and registers with an actuating device 17, e.g. a cam or vane, attached at a fixed position on the hoistway wall H, for indicating the position of the pLatform 12a relative to the landing sill S. Leveling transducers and the like Lor indicating relative position, are well known. Alternatively, the actuating cam or vane may be mounted on the elevator guide rails (not shown).
Figs. 2-3 show a first arrangement in which the drive shaft 24 of the drive sheave 18 is mounted for rotation on the frame 28a in a pair of spaced bearing 15 ~ blocks 27. The drlve sheave 18 is connected to a conventional gear reducer 34, which in turn engages the cutput shaft of a main hoist motor 30. The gear reducer may be a so-called "hollow output shaft" gear reducer, and is "hung' on an extension of the sheave drive shaft. The motor 30 is flange mounted to the gear box of the reducer 34.
A disk brake 36 (Fig. 3, 3a~ on the hoist motor output shaft may be selectively engaged to lock the main hoist motor 30, and thereby the drive shaft 24, from rotating.
Since the main hoist motor and reduction gear box are hung from the shaft 24, the gear box must have a torque arm connection, i.e. coupler 32 as shown diagram-matically in Fig. 1, to produce the reaction to its output 47~33 torque. In Figs. 2-3, this torque arm connection includes a motor-driven linear actuator, which comprises an auxiliary motor 37, pivotally connected at 41 to the frame, driving an output screw 38. The screw 38 is threaded through a nut 39 retained by a yoke shaped torque arm flange 40 of the gear box housing 34, such that rotation of the screw 38 by motor 30 causes the flange 40 to move linearly back and forth along the screw axis. Preferably the ~ut 39 is pivotable in the yoke 40, as indicated at 43, the pivotable connections of the nut 39 and motor 37 permltting the yoke 40 to move back and forth without binding.
As can be seen, when the flange 40 is displaced by the screw 30, the entire gear box housing and shaft 24, which are locked together as a unit when the brake 36 is engaged, rotate about the axis of shaft 24, thereby rotating the drive sheave 18. As such, the cables 16 and elevator car 10 can be moved a limited amount for re-leveling without releasing the braXe or energizing the hoist motor.
A pair of mechanical end stops 42 are provided at either end of the travel of flange 40 to limit the extent by which the motor/gear box unit can pivot and also to engage the gear box in the event of a failure of the screw 38 or nut 39. In addition, as shown, a pair of switches 44, 45 and a centering cam 46 may be pro~ided as an indication of the center position of the flange 40.
r:
.
-10- :
.
-~2~47B3 .
Fig. 3a is similar to Figs. 2-3, except ~hat the output shaft of motor 30 is coupled to the gear reducer 34 through a pulley/belt arrangement 34a, rather than being connected directly to the input shaft of the reducer 34. The mechanical stops and centering switches have been omitted for-clarity. In Fig. 3a, gear reducer 34 is upside down, as compared with Fig. 3, and motor 30 is fixed to the upper portion of the housing for clearance.
Also, yoke flange 4Q extends from the end of the reducer housing opposite that in Fig. 3, but in operation the leveling mechanisms of Figs. 2-3 and 3a are equivalent.
In the embodiment shown in Figs. 4-5, the drive shaft 24 of the drive sheave 18 is supported in bearing blocks 26b on a pair of spaced channels 48 of the frame.
The linear actuator motor 37 is pivotally mounted at pivot 50 to a portion of the frame 28b so as to be overhead of the drive sheave 18. An idler sheave 20b is also mounted in bearing blocks 52 on the channel members 48 so that the ropes 16 pass over the drive sheave 18 and idler sheave to the car 10 and counterweights 22, respectively. The hoist ropes are double-wrapped for added traction.
The gear reducer 34 extends vertically up from the shat 24 so that the motor 30 and torque arm flange 40 are overhead to engage the screw portion 38 of the linear actuator shaft. As in the Figs. 2-3 embodiment, the screw 38 engages the fl~nge 40 at an angle tangent to the axis of rotation of the gear box housing about shaft 24.
~Z~47~33 Figs. 6-7 illustrate an embodiment of the invention in which the drive shaft 24 of the sheave 18 is pivotably supported by the frame. A pair of support channels ~0 are pivotably supported between frame members 62, and rotatably support the shafts of the drive sheave 18 and idler sheave 20d on opposite sides of the pivot. The output shaft of the main hoist motor 30, through a solidly mounted gear reducer 34, is connected to the drive shaft 24 of the drive sheave 18. A linear actuator 32 is attached between the channels 60 and the fixed portion of the frame 28d, so that the channels, sheaves, and main hoist motor may be pivoted about the pivot axis. A pair of end stops 42a are provided, which limit the angle of pivot of the channels 60 provided by the screw 38/nut 39 combination.
Although not shown, centering switches may be provided in a manner similar to the other embodiments. As shown, the ropes are double wrapped around the drive and idler sheaves for greater traction. t Fig. 8 illustrates a leveling mechanism used with a gearless elevator drive. A DC motor 30' has an output drive shaft 24' supported in bearings in a pair of spaced pedestals 27', forming part of frame 28'. Drive sheave 18' is mounted directly on the output shaft 24'.
A torque-arm connection, in the form of linear actuator 37, 38 engaging a nut 39` pivotably mounted to ,-the motor housing, absorbs rotational torque when the motor is running. The linear actuator is also capable i;
of selectively pivoting the motor 30' and drive sheave ~Z447~3:3 18' about sheave axis 24' when the motor is stoppe`d and disc brake 36' is engaged. End stops 42' may be provided on either side of the motor (one pair is shown), between the motor and frame, to limit rotational movement.
S A strain gauge 90 is positioned on linear actuator 37, 38,-to provide an indication of the instantaneous imbalance in the system. Alternatively, a pressure transducer or the like may be employed. The load signal may be used as an input to known control systems for starting a stopped car, which pre-torque the main hoist motor to compensate for imbalance, prior to releasing the brake.
As discussed above, imbalance results from a number of factors. Unlike the known inputs to such compensating systems, typically weight sensors attached to the car, the sensor 90 provides a true indication of system imbalance acting on the main drive sheave, without regard to the source of that imbalance.
In Fig. 8, the motor shaft 24', which is also ~0 the drive shaft for drive sheave 18', extends from either end of the motor housing to be supported in bearing blocks.
Alternative support configurations are possible. ~or ; example, one end of the shaft may be supported in a bearing in the end bell 31' portion of the motor housing. This bearing may then extend into a bearing into the pedestal block.
In operation, once the car is at the landing, the main hoist motor is stopped and the elevator brake engages. While the car is at the landing, the net load of the car, and the amount of elongation in the hoist ~L2~47~33 ropes, may change as passengers enter and leave. If the elevator cah moves away from the landing sill S by greater than a predetermined distance, the auxiliary motor 37 is actuated to either raise or lower the car.
A loaded elevator, arrivlng at a lobby of a fairly tall building, might have to re-level several times as the passengers exit the elevator. In the system in accordance with the invention, the cab platform may b,é
maintained very close to the level of the landing since corrections as small as 1/16" can easily be made. It is almost impossible to release the brake and move the main hoist machine such a small distance, or as quickly and as smoothly as the present invention.
If desired, the present invent1on may be utilized for final positioning of the car at the landing sill when the elevator is arriving. Accordingly, the main hoist motor may be used to move the cab to approximately the position of the sill, and thereafter the auxiliary positioning system may be actuated for final leveling.
~o However, as discussed above, even elevator systems in which the main hoist motor initially positions the cab with sufficient accuracy have the need for the re-leveling feature when the doors are open.
Fig. 9 is a diagram of an illustrative control circuit for adjusting the position of the car relative to the landing sills. A conventional circuit for actuating the main hoist motor includes a pair of relays 110, 112, which enerize the main hoist motor for the up and down ~2447~33 directions, respectively, and a relay 114 which when actuated releases the holding brake. The hoist up relay 110, when actuated, also opens "up" switch 116, and closes "up" switch 118. The down relay 112, when actuated opens "down" switch 120 and closes "down'i swi.ch 122. A door interlock switch 128 is also provided, which interrupts the main hoist motor actuating circuit when the doors are open, so that the elevator car cannot be moved by the main hoist motor.
The element 200 is a switch (relay contact) that is opened as the car begins a high speed run, and closes, during slowdown, as the car approaches the target floor. For stopping the moving elevator car, a pair of leveling switches, a "platform level up" switch 130, and a "platform level down" switch 132, are provided. Switches 130, 132 are part of positioning indicator 1~ (see Fig.
1). When the sling and cab of the moving elevator reach a landing~ depending upon the direction of car movement, switch 130 or 132 will be closed to actuate a sling level up relay 134 or a sling level down relay 136. The relays 134, 136 open the sling level up switch 138 and sling level down switch 140, respectively, to open the energizing circuit of the actuated relay 110 or 112, and stop the main hoist motor.
An "up run" switch 124 and "down run" switch 126 are also provided. The switches 124 and 126 are used for re-starting a stopped elevator once the doors are again closed. As shown, the switches 124, 126 by-pass`
the switches 118, 12?, 138 and 140 so that, once the doors .
~;~44783 close (re-closing switch 128), the relay 110 or 112 may be actuated, to re-start the elevator, regardless of the position of the other switches. Switches 124, 126 should open about the time that the door zonè is energized so that switches 138 and 140 have control of the stopping of the elevator.- Finally, a door zone switch 142 ~see also Fig. 1) is normally connected to be closed when the sling is in position near the sill to actuate a door zone relay 144 to allow power door operation.
The switch 200 prevents the "Level Up", `'Level Down", and "Door Zone" relays from operating as the car leaves a landing, or is running past landings at high speed, or during the initial part of the deceleration if the slowdown ~istance is greater than one floor. It is closed while a car is stopped.
A pair of oppositely acting "run" switches 174, 176 are arranged in series with the switches 150, 152 and switches 44 r 45, whose function is described below~
When the car is stationary, switch 174 is closed and switch 176 is open. While the car is moving, switch 174 is open and switch 176 is closed. Accordingly, only one of the parallel circuits, that containing switches 150, 152 or that containing switches 44, 45,is active at one time.
As noted above, "platform level up" switch 130 2S and `'platfo~m level down" switch 132 are mounted to be actuated when the elevator car is not level with the sill.
These switches, through relays 134, 136, are used to stop the moving car level with the sill.
47~33 Relays 134, 136 also actuate switches 150, 152.
The circuit containing switches 150 and 152 is inoperative while the car is moving (switch 174 is open), and thus in this embodiment switches 150, 152 do not affect the stopping procedure. But, when the main hoist motor is stopped, i.e.
when the switch 174 is closed, and the car is stopped at the landing, the circuit containing switches 150, 152 is active. Closing of switch 150 or 152, which occurs when one of the switches`l30, 132 is closed (indicating the car is not level), will re-level the car as described below.
In the position of the switches shown, the car is stopped at the landing, and switch 174 is closed. The platform either had been stopped by the main hoist motor below the level of the sill, or has since moved down relative -to the sill. As a-resuIt, the "platform ievel up" switch r 130 has been closed. Closing of switch 130 energizes relay 134 to close switch 150. A corresponding result .
occurs if the car is too high, actuating switch 132, to cause switch 152 to close. `
The switches 150, 152 selectively actuate a .
"platform level up relay" 154 or a "platform level down relay" 156. Actuation of either of the relays 154, 156 `i closes an appropriate switch to energize the auxiliary ; motor 37, to actuate the linear actuator and cause the car to move up or down. The relays 154, 156 are shown r;',' schematically as being connected to a triple switch 160, !~
for reversing the direction of rotation of the motor 37; ,r-~
however, any appropriate arrangement may be used.
47~3 In view of the direct electrical positioning control effected by this arrangement, a transducer or switches 150, 152, or other such position indicator may be directly mounted on the cab, so that the level of the cab is accurately measured and precisely controlled.
When the elevator car is repositioned, the torque arm 40 or 40a (Figs. 6-7) moves relative to the screw 38, that is, the linear actuator is no longer at its center position, which causes one of the switches 44, 45 to close.
As shown the switches 44, 45 are arranged in parallel relative to the corresponding switches 150, 152 and while the car is stopped, switch 176 is open, so that switches 44, 45 do not interfere with the leveling function of switches 15Q, 152. -`
.
As soon as~the car moves away from the landing toward the next floor, switch 174 is opened, disabling the circuit containing switches 150, 152, and switch 176 is closed. At such time, if the linear actuator is out of center position, the actuator centering switches 44, ~5 energize the appropriate relay 154 or 156 to cause motor 37 to re-center the tor~ue arm.
Switch 176 should be closed responsive to movement of the car between landings. Closing of switch 176 may ~e responsive to energization of the main hoist motor. -Alternatively, the closing of switch 176 can be velocity responsive. In this case, the closing of switch 176 should be delayed until the car velocity is appreciably greater -18- ~
~lZ~4q~33 than that produced by the linear~actuator so as to "mask"
the velocity change produced by the linear actuator during the centering operation.
The foregoing represent preferred embodiments of the invention. Variations and modifications of the embodiments shown will be apparent to persons skilled in the art without departing from the inventive concepts disclosed herein. For example, the drive arrangement in the Figs. 2-7 embodiments may also be gearless. Also, }O while a screw-type linear actuator has been shown, such is only illustrative and any suitable adjustment mechanism or device, hydraulic, electrical, or mechanical, which is capable of taking up the counter-torque of the m~tor and of selectively pivoting the motor and sheave drive shaft may be employed. All such modifications and variations are intended to be within the scope of the present invention as defined in the following claims.
Claims (12)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An elevator having a car supported by a cable and vertically displaceable between landings in a hoistway, comprising:
a frame;
a drive sheave supporting said cable and having a drive shaft rotatably support by said frame;
a main motor means having a housing coupled to said drive shaft for rotating said shaft and for transmitting rotational torque between said motor and said shaft, for moving the car between landings;
a brake means selectively engageable for stopping said motor means and drive shaft for holding the car at a selected landing;
means connected between said motor means and frame for absorbing reaction torque and including auxiliary drive means for selectively pivoting said motor means and thereby said drive sheave about the drive sheave axis or an axis parallel thereto while said brake is engaged, for raising or lowering the position of the elevator car;
means for sensing a center position of said housing, and means responsive to the travel of the elevator car between landings for actuating said auxiliary drive means for returning said housing to its center position; and means positioned at each landing and on said elevator car for sensing misalignment between said car and a selected landing and for actuating said auxiliary drive means in response thereto for re-leveling the car.
a frame;
a drive sheave supporting said cable and having a drive shaft rotatably support by said frame;
a main motor means having a housing coupled to said drive shaft for rotating said shaft and for transmitting rotational torque between said motor and said shaft, for moving the car between landings;
a brake means selectively engageable for stopping said motor means and drive shaft for holding the car at a selected landing;
means connected between said motor means and frame for absorbing reaction torque and including auxiliary drive means for selectively pivoting said motor means and thereby said drive sheave about the drive sheave axis or an axis parallel thereto while said brake is engaged, for raising or lowering the position of the elevator car;
means for sensing a center position of said housing, and means responsive to the travel of the elevator car between landings for actuating said auxiliary drive means for returning said housing to its center position; and means positioned at each landing and on said elevator car for sensing misalignment between said car and a selected landing and for actuating said auxiliary drive means in response thereto for re-leveling the car.
2. An elevator as defined in claim 1, wherein said drive shaft is mounted on said frame and said pivot axis is concentric with the drive sheave axis.
3. An elevator as defined in claim 2, wherein said motor means has an output shaft and a plurality of gears coupling said output shaft and said drive shaft.
4. An elevator as defined in claim 3 comprising a linear actuator connected between said housing and said frame for selectively pivoting said housing about the drive sheave axis.
5. An elevator as defined in claim 4, wherein said linear actuator is a screw-type linear actuator.
6. An elevator as defined in claim 4, wherein said linear actuator includes an actuator rod engaging said housing at an angle tangent to the drive sheave axis.
7. An elevator as defined in claim 1, comprising means for pivotally supporting said drive shaft on said frame about a second axis spaced from the drive shaft axis, and wherein the means connected between said motor means and frame is arranged for pivoting said motor means and said drive shaft about said second axis.
8. An elevator as defined in claim 7, further comprising an idler sheave, wherein said drive sheave and idler sheave are disposed on opposite sides of said second axis.
9. An elevator as defined in claim 1, wherein said car includes a cab having a platform and comprising position sensor means mounted on said cab and fixed relative to said platform for controlling said auxiliary drive means.
10. An elevator as defined in claim 1, comprising position sensor means, mounted on said car, and control means for disabling said motor means and engaging the brake when said car is at a landing, wherein said control means is responsive to said position sensor means, when said motor means is disabled and said brake is engaged, for selectively actuating said auxiliary drive means.
11. An elevator as defined in claim 10, comprising means for detecting a center position of said auxiliary drive means, wherein said control means is responsive to the center position-detecting means when said main motor means is energized for actuating said auxiliary drive means for returning said auxiliary drive means to its center position.
12. An elevator as defined in claim 1, comprising load sensor means connected to the means for absorbing reaction torque for generating a signal indicative of elevator unbalance, said signal being useable for controlling restarting of a stopped elevator.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US64032584A | 1984-08-13 | 1984-08-13 | |
| US640,325 | 1984-08-13 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1244783A true CA1244783A (en) | 1988-11-15 |
Family
ID=24567778
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000487892A Expired CA1244783A (en) | 1984-08-13 | 1985-07-31 | Elevator system with improved car leveling |
Country Status (2)
| Country | Link |
|---|---|
| CA (1) | CA1244783A (en) |
| GB (1) | GB2163127A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2482049C2 (en) * | 2008-02-26 | 2013-05-20 | Отис Элевейтэ Кампэни | Method of control over elevator cabin and elevator system |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GR1001319B (en) * | 1992-08-05 | 1993-08-31 | Eleytherios Frasiolas | Elevator sorter slip correction mechanism that works with a wire rope. |
| WO2004046007A1 (en) * | 2002-11-18 | 2004-06-03 | Mitsubishi Denki Kabushiki Kaisha | Elevator device |
| US7360630B2 (en) * | 2004-04-16 | 2008-04-22 | Thyssenkrupp Elevator Capital Corporation | Elevator positioning system |
| GR1005680B (en) * | 2006-10-24 | 2007-10-11 | Κωνσταντινος Τσασιταλιδης | Traction elevator's machine with torque-strained hollow-shaft electro-reducer |
| WO2009110907A1 (en) * | 2008-03-07 | 2009-09-11 | Otis Elevator Company | Secondary elevator car leveler |
| DE102010021715A1 (en) * | 2010-05-27 | 2011-12-01 | Aufzugswerke M. Schmitt & Sohn Gmbh & Co. | elevator system |
| KR20130137670A (en) * | 2011-02-28 | 2013-12-17 | 오티스 엘리베이터 컴파니 | Elevator car movement control in a landing zone |
| FI125200B (en) * | 2013-07-04 | 2015-06-30 | Kone Oyj | Arrangement to reduce the displacement of the elevator car caused by the change in load |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR1202830A (en) * | 1957-06-17 | 1960-01-13 | Micrometric adjustment device for the position of moving parts with motor-controlled displacement | |
| IT1168049B (en) * | 1981-10-27 | 1987-05-20 | Sicor Spa | MICRO-LEVELING ARRANGEMENT ON THE FLOOR OF THE LIFT AND LIFT CABIN IN GENERAL |
-
1985
- 1985-07-31 CA CA000487892A patent/CA1244783A/en not_active Expired
- 1985-07-31 GB GB08519247A patent/GB2163127A/en not_active Withdrawn
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2482049C2 (en) * | 2008-02-26 | 2013-05-20 | Отис Элевейтэ Кампэни | Method of control over elevator cabin and elevator system |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2163127A (en) | 1986-02-19 |
| GB8519247D0 (en) | 1985-09-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR890003878B1 (en) | Elevator system | |
| JP2000327241A (en) | Elevator system and speed governor | |
| CA1244783A (en) | Elevator system with improved car leveling | |
| KR20040099428A (en) | Elevator control system | |
| US10569992B2 (en) | Elevator apparatus | |
| JPH0777956B2 (en) | Elevator safety equipment | |
| US7581621B2 (en) | Method and apparatus for controlling advance opening of doors in an elevator | |
| CN105829231A (en) | Lift with an absolute positioning system for a double-decker cabin | |
| US20230294960A1 (en) | Elevator | |
| JPS6055436B2 (en) | Elevator hoisting device | |
| US20040238288A1 (en) | Safety system for restraining movement of elevator car when car doors are open | |
| JP2006290575A (en) | Elevator device | |
| US1952728A (en) | Hoisting apparatus | |
| JPH08198542A (en) | Elevator with braking force adjusting device | |
| JP2002087716A (en) | Double deck elevator | |
| JP2018002437A (en) | Elevator | |
| US2482458A (en) | Elevator | |
| JP2003128363A (en) | Main rope regulating device of elevator for connecting bridge | |
| JP7538093B2 (en) | Test method and device for elevator standby brake | |
| EP4488212A1 (en) | Elevator systems | |
| US20230242373A1 (en) | Elevator systems with improved monitoring | |
| JPH0266085A (en) | Device for controlling cage position of elevator | |
| JPH01271387A (en) | Elevator having no machine housing | |
| CN101602457B (en) | Elevator device | |
| KR100898205B1 (en) | Elevator device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |