Abstract: An overload valve assembly for a pneumatic vacuum elevator is disclosed. The overload valve assembly for a pneumatic vacuum elevator is characterised by a fastening means, a pad with a centre hole, an arresting plate with a centre hole, a disc plate with a centre hole, a bottom bush, a spring and a top bush bounded with a nut. Here, the pad, the arresting plate, the disc plate, the bottom bush, the spring and the top bush bounded with the nut is fitted over the fastening means. The overload valve unit is configured to function based on spring actuation mechanism and ensure the maximum permissible limit of pay load in the elevator cabin assembly.

Abstract: An apparatus for controlling a position of an elevator in a hoistway includes a fixed belt and a dynamic leveling control module adapted for attachment to the elevator and coupled to the fixed belt. The control module includes a position encoder coupled to the fixed belt, a processor electrically connected to the position encoder, and a communications interface electrically connected to the processor and adapted for communication with an elevator controller for the elevator. The control module determines a velocity, a position, and an acceleration of the elevator in response to a count signal output from the position encoder, and calculates a dynamic slowdown distance relative to an elevator landing for each elevator stop. The control module communicates the dynamic slowdown distance to the elevator controller to initiate slowdown of the elevator. The control module determines a new value of said dynamic slowdown distance for each elevator stop.

Abstract: A remote jig control system may comprise a jig configured to place a car body to a particular position, a wireless magnetic sensor installed in the jig, a control panel wirelessly connected with the wireless magnetic sensor via first wireless communication to receive state information about the jig from the wireless magnetic sensor, a gateway connected with the control panel via the first wireless communication to receive the state information, a user terminal connected with the gateway via second wireless communication to receive the state information; and monitoring server configured to receive the state information from the gateway and store the state information, wherein the control panel is configured to be controlled through the user terminal to generate a jig control signal corresponding to the state information.

Abstract: The present invention relates to a control device for pressure control in a hydraulic system, especially of an elevator-system, the control device is adapted to control an output variable of an inverter supplying a hydraulic pump of the hydraulic system with electric energy, the output variable is adapted to adjust the speed of the hydraulic pump in order to at least partly compensate for a leakage of operating fluid in the hydraulic pump. Further, the invention relates to an elevator-system that includes a hydraulic pump, an inverter, and a control device which controls a supply of the hydraulic pump with electric energy from the inverter.

Abstract: In one or more example embodiments, an apparatus to control an elevator may include a motor having a rotor configured to rotate with a magnetic axis to drive the elevator at a speed based on a current applied thereto; and a processor configured to regulate the speed of the elevator without information on a speed or an angle of the rotor from an encoder or motion sensor.

Abstract: An apparatus for controlling a position of an elevator in a hoistway includes a fixed belt and a dynamic leveling control module adapted for attachment to the elevator and coupled to the fixed belt. The control module includes a position encoder coupled to the fixed belt, a processor electrically connected to the position encoder, and a communications interface electrically connected to the processor and adapted for communication with an elevator controller for the elevator. The control module determines a velocity, a position, and an acceleration of the elevator in response to a count signal output from the position encoder, and calculates a dynamic slowdown distance relative to an elevator landing for each elevator stop. The control module communicates the dynamic slowdown distance to the elevator controller to initiate slowdown of the elevator. The control module determines a new value of said dynamic slowdown distance for each elevator stop.

Abstract: A control system for a hydraulic elevator. The system (10) controls an elevator (1) which includes an elevator cylinder (5) with a piston (5a) coupled to a car (2), a pump (4) having an outlet coupled to the elevator cylinder (5), and an electric motor (3) coupled to the pump (4). A speed regulator (11) for controlling the speed of the car (2) is driven in predetermined modes, such that the pump (4) rotates at predefined speed. The speed regulator (11) is driven such that the motor (3) of the pump (4) is supplied with a voltage having a frequency (f) the value of which corresponds to a predefined speed value (?), increased by an amount (cft; fts, ftD) which is a predetermined function of the working pressure (P1) of the pump (4). This balances the effect of the leakage of operating hydraulic fluid in the pump (4).

Abstract: The invention relates to a control device (1) for a working fluid for operating a hydraulic drive (11) such as is used, in particular, for an elevator.

Abstract: The elevator safety rescue system is an electro-hydraulic system particularly suited for use in rack and pinion drive elevators installed with tall towers, mines, smoke stacks, and other structures having relatively large elevations or depths. The system includes a positive displacement hydraulic pump driven by the output shaft of an electric elevator drive motor. An electro-hydraulic valve is electrically powered to maintain an open condition to allow unrestricted hydraulic flow through the pump during normal operation. In the event of an elevator malfunction, electrical power is terminated to the valve, causing the valve to close and thus requiring all hydraulic fluid to pass through a restrictor. The restrictor limits the flow of hydraulic fluid through the hydraulic pump, thus limiting its rotational speed and rotational speed of the elevator drive motor to which it is attached, thereby allowing the elevator to descend or climb (with counterweight) at a safe speed.

Abstract: A control system is provided and includes energy accumulators (20; 120) coupled to a first inverter (10) and controlled through a second inverter (12). These accumulators (20; 120) are adapted to store the energy generated by an electrical machine (3) associated with the elevator apparatus (1), and the energy coming by a source and optionally not used by the machine (3), as well as to deliver the stored energy towards the machine (3) when this requires energy with a power higher than a threshold. The system is arranged to automatically cause the lifting of the car (2) up to the highest floor when preset conditions occur in a time interval of inactivity of the elevator apparatus (1).

Abstract: The elevator safety rescue system is an electro-hydraulic system particularly suited for use in rack and pinion drive elevators installed with tall towers, mines, smoke stacks, and other structures having relatively large elevations or depths. The system includes a positive displacement hydraulic pump driven by the output shaft of an electric elevator drive motor. An electro-hydraulic valve is electrically powered to maintain an open condition to allow unrestricted hydraulic flow through the pump during normal operation. In the event of an elevator malfunction, electrical power is terminated to the valve, causing the valve to close and thus requiring all hydraulic fluid to pass through a restrictor. The restrictor limits the flow of hydraulic fluid through the hydraulic pump, thus limiting its rotational speed and the rotational speed of the elevator drive motor to which it is attached, thereby allowing the elevator to descend at a safe speed.

Abstract: The system (10) allows control of an elevator apparatus (1) which comprises an elevator cylinder (5) with a piston (5a) coupled to a car (2), a pump (4) having the outlet coupled to the elevator cylinder (5), and an electric motor (3) coupled to the pump (4). The system comprises a speed regulator (11) associated with the motor (3) for controlling the speed of displacement of the car (2), and is predisposed for driving the speed regulator (11) in predetermined modes, such that the pump (4) rotates at a speed having a predefined value (W). The system (10) is also predisposed for driving the speed regulator (11) such that the motor (3) of the pump (4) is supplied with a voltage having a frequency (f) the value of which corresponds to said predefined speed value (?), increased by an amount (cft; fts, ftD) which is a predetermined function of the working pressure (P1) of the pump (4), such as to balance at least in part the effect of the leakage of operating hydraulic fluid in the pump (4).

Abstract: A hydraulic elevator for an elevator shaft having guide rails for an elevator cab. The hydraulic elevator has no machine room and includes an assembly disposed between the guide rails and a tank, a pump mounted in the tank, a motor mounted in the tank for driving the pump, and a control valve unit mounted on the tank and in working relationship with the pump. One of the pump and the motor is disposed above the other of the pump and the motor. The hydraulic elevator further includes a hydraulic drive mounted on the tank, the hydraulic drive being configured to move the elevator cab by a cable; and an emergency operating and monitoring device disposed outside of the elevator shaft and connectable to the control valve unit by a measuring line.

Abstract: The present invention relates to a stand alone system for generating electrical power using hydraulic supports on which a weighted object is mounted. A pump injects fluid into the supports to raise the weighted object and thereby store energy in the elevated object. A valve can be opened to deliver fluid under pressure to a turbine or hydraulic motor driven generator to generate electricity.

Abstract: A height control mechanism for a lift device includes an elongated rail and an actuator slidingly mounted thereto. The actuator is biased toward a first end of the rail, and a proximity sensor is mounted proximate the second end of the rail. A cable pulls the actuator toward the second end of the rail as the lift device is elevated. When the proximity sensor detects the presence of the actuator, a signal is generated to halt further elevation. The position of the proximity sensor along the rail can be adjusted to set the maximum height of the lift device. A second proximity sensor, responsive to the presence of the actuator, can also be secured to the rail to generate a signal indicating that the lift device has been elevated off of the ground by a short distance.

Abstract: An elevator governor includes a selectively powered switch (60) that is activated when an elevator car moves at a speed that exceeds a selected limit. The speed limit is lower than normally expected car speeds during normal elevator operation. The switch (60) is activated by a moving member (66) that moves into a switch-activation position responsive to movement of a rotating member (36) that corresponds to movement of an elevator car. The arrangement allows for a primary governor to prevent elevator speeds from exceeding a first selected limit and a secondary governor to prevent elevator speeds from exceeding a second, lower limit.

Abstract: Disclosed herein is an elevator which has an improved structure such that a balance weight offsets the weight of a cage, passengers, and cargo to the utmost, according to changes in weight of the passengers and cargo, thus reducing power consumption. In the elevator of the present invention, a gear ratio of a transmission (21) is adjusted in consideration of the number of passengers or the weight of cargo, so that power consumption required for operating the elevator is reduced. Furthermore, in the case of use of an electronic variable capacity hydraulic motor (291), the elevator is controlled depending on changes in weight of passengers and cargo, such that a balance weight (12) offsets the weight of a cage, the passengers and cargo to the utmost, thus reducing power consumption required for operating the elevator.

Abstract: A hydraulic elevator with a pressure accumulator includes a pump fir conveying hydraulic oil between the pressure accumulator and a hydraulic drive, such that the direction of rotation of the pump can be changed. An electrically controlled cylinder line stop valve is installed on one side of the pump, and an electrically controlled accumulator line stop valve is installed on the other side of the pump. Both valves are ON-OFF valves. To prevent sudden disruptive pressure changes when the valves are opened before the start of travel of the car, the pressure in the section of the line between the pump and the cylinder line stop valve and in the section of the line between the pump and the accumulator line stop valve can be varied such that, when the car is at a standstill, the pressure differences are largely eliminated before the valves are opened.

Abstract: The invention relates to a hydraulic lift comprising a pressure accumulator (17). Hydraulic fluid can be transported between the pressure accumulator (17) and a hydraulic drive (2) by means of a pump (13), the rotational direction of the pump (13) being variable. According to the invention, there is no valve between the pressure accumulator (17) and the pump (13), and means are provided for preventing the pressure accumulator (17) from being discharged when the lift is at a standstill. In terms of said means, either a screw pump is used as a pump (13), or an electrically controllable leakage stop valve (31) is arranged in a leakage line (30) extending from a leakage port of the pump (13) to the tank (21), said stop valve being closed when the lift is at a standstill. The invention enables a hydraulic lift to be operated in an energy-saving and convenient manner, using a simple hydraulic circuit, and prevents the pressure accumulator (17) from being discharged when the lift is at a standstill.

Abstract: A vehicle lift control maintains multiple points of a lift system within the same horizontal plane during vertical movement of the lift engagement structure by synchronizing the movement thereof. A vertical trajectory is compared to actual positions to generate a raise signal. A position synchronization circuit synchronizes the vertical actuation of the moveable lift components by determining a proportional-integral error signal.

Abstract: A pump is situated between the hydraulic drive and the accumulator, this pump being driven by a motor and conveying hydraulic oil from the hydraulic drive to the accumulator and vice versa without the presence of control valves which influence the flow of hydraulic oil, such as proportionally pilot-operated valves. Since the pump is subjected to the pressure Pz in the cylinder line and the pressure Ps in the accumulator line, the motor of the pump only has to work against the differential pressure and in certain operating states, can even function as a generator and release electrical energy through a power output device controlling it. The speed of the car is controlled through the control of the motor alone by a control and regulation device, through the power output device.

Abstract: The invention concerns a hydraulic elevator with a pressure accumulator (17). Hydraulic oil can be conveyed by a pump (13) between the pressure accumulator (17) and a hydraulic drive (2), such that the direction of rotation of the pump (13) can be changed. An electrically controlled cylinder line stop valve (12) is installed on one side of the pump (13), and an electrically controlled accumulator line stop valve (15) is installed on the other side of the pump (13). Both valves (12, 15) are ON-OFF valves.

Abstract: A control valve unit for a hydraulic elevator includes two control valves wherein the flow of hydraulic oil from a tank to a lifting cylinder driving an elevator cabin and/or from the lifting cylinder to the tank can be controlled. In case of an upward movement of the elevator cabin, hydraulic oil is conveyed by a pump driven by an electromotor from the tank through the control valve unit to the lifting cylinder. In the case of a downward movement of the elevator cabin, the hydraulic oil flows through the control valve unit to the tank without the pump working. The control of the upward movement and the downward movement of the elevator cabin is achieved by one single pilotable control valve, respectively, that are provided to act as a check valve as well as a proportional valve.

Abstract: A lift system that coordinates the raising and lowering of a vehicle relative to a surface by using wireless communications is provided. The lift system includes at least two lift mechanisms each having a post, a carriage, an actuating device and a control device. The carriage is slidably coupled to the post and is adapted to support a portion of the vehicle. The actuating device is coupled with the carriage and is capable of moving the carriage relative to the post. The control device is coupled with the actuating device and is capable of communicating by wireless signals with the other control device. The control devices communicate by wireless signals to coordinate the movement of the carriages relative to the posts to raise or lower the vehicle. Further, a rechargeable battery may provide power to the control device to allow for increased mobility of the lift system.

Abstract: A hydraulic power unit for use in conjunction with an elevator construction having an elevator car operably connected to a pair of hydraulic rams comprises a chassis having a floor and a sidewall forming a hydraulic fluid sump region. The hydraulic rams are mounted to the floor in the sump region. A hydraulic fluid reservoir is supported by the chassis, which also supports a pump/motor unit for the rams. Leveling feet mounted to the chassis allow the power unit to accommodate a variety of conditions in the hoistway pit.

Abstract: A pump is situated between the hydraulic drive and the accumulator, this pump being driven by a motor and conveying hydraulic oil from the hydraulic drive to the accumulator and vice versa without the presence of control valves which influence the flow of hydraulic oil, such as proportionally pilot-operated valves. Since the pump is subjected to the pressure Pz in the cylinder line and the pressure Ps in the accumulator line, the motor of the pump only has to work against the differential pressure and in certain operating states, can even function as a generator and release electrical energy through a power output device controlling it. The speed of the car is controlled through the control of the motor alone by a control and regulation device, through the power output device.

Abstract: A method for controlling a hydraulic elevator whose car can be displaced by a hydraulic drive mechanism by hydraulic oil fed through a cylinder line or evacuated from said hydraulic drive mechanism by a pump that cooperates with a first control valve unit and a second control valve unit, wherein the flow the hydraulic oil is controlled by a measuring device and operation of the elevator can be controlled and regulated by a control apparatus. The load of the elevator car is determined by a load pressure sensor detecting pressure PZ in the cylinder line and is controlled preferably in a constant manner by changing the control of the second control valve unit in such a way that movement of the elevator car can be controlled in a very precise manner. When the elevator car is descending, the dropping pressure PZ in the cylinder line is regulated by changing the first control valve unit in such a way that the descending movement of the elevator-cabin can also be controlled in a very precise manner.

Abstract: A hydraulic elevator with a pressure accumulator acting as a counterweight, includes a first pump for conveying hydraulic oil through a pump line, at least one valve unit, and a cylinder line to and from a hydraulic drive for a car, a second pump for conveying hydraulic oil by way of a solenoid valve from and to the pressure accumulator, which hydraulic oil can be supplied to and withdrawn from a tank. The two pumps are connected rigidly to each other and can be driven by an electric motor, the speed of which can be regulated. A single valve unit is installed between the first pump and the hydraulic drive, the valve unit being a relay-controllable valve and a first nonreturn valve connected in parallel to the relay-controllable valve. A control/automatic regulation unit is provided, and in order to control the speed of the car, acts on a power regulating unit for the electric motor, on the solenoid valve, and also, during descents, on the relay-controllable valve.

Abstract: The invention pertains to a control valve unit (28) for an hydraulic elevator. It contains two control valves (5, 15) with which the flow of hydraulic oil from a tank to a lifting cylinder driving an elevator cabin and/or from said lifting cylinder to said tank can be controlled. In case of upward movement of said elevator cabin hydraulic oil is conveyed by means of a pump driven by an electromotor, from said tank through said control valve unit (28) to said lifting cylinder, whereas in case of downward movement of said elevator cabin said hydraulic oil flows through said control valve unit (28) to the tank without the pump working. In accordance with the present invention for control of the upward movement and the downward movement of said elevator cabin in said control valve unit (28) one single pilotable control valve (5, 15) respectively is provided for, each of which acts as check valve as well as as proportional valve.

Abstract: A vertically oriented hydraulic power unit for an elevator drive includes an outer tank for drive fluid and an inner tank for fluid used to submerge and cool a motor, the fluids being exchangeable to maintain temperature in the inner tank at or below a specified maximum temperature. Oil returning from an elevator piston is fed into said inner tank to keep the inner tank sufficiently cool.

Abstract: Attachments for floor and yard trucks with a lift mast, especially for fork lift trucks, have a lift carriage (8) which has two side plates (9, 10) and two horizontal beams (12/14, 13) situated one over the other with a clearance (“h”) between them, on which there is held at least one hydraulically powered element from the group: load carrier, “transport securing means,” rotating device, tilting device, pushing device, pulling device, holding device, lifting device, fork shifting device, lateral shift frame (1), each with the corresponding hydraulic drive (14). The front sides of the horizontal beams (12/14, 13) and the rear edges of the side plates (9, 10) of the lift carriage (8) are disposed between two vertical planes defining between them a space (7) wherein the at least one hydraulic jack (14) is arranged and the corresponding control unit (18) is disposed.

Abstract: An apparatus is provided for storing vehicles. A vertical support structure is mechanically coupled to a horizontal support structure. Multiple support platforms are provided, including at least an upper vehicle support platform and a lower vehicle support platform. At least one lift arm is pivotally coupled between the vertical support structure and the upper vehicle support platform. A collapsible linkage connection is provided between the upper vehicle support platform and the lower vehicle support platform. A lower vehicle support platform is suspendable below the upper vehicle support platform by the collapsible linkage connection. A control system is utilized to operate the at least one lift arm in order to move the apparatus between modes of operation. In a first vehicle loading position, the upper vehicle support platform and the lower vehicle support platform are in a down position with the upper vehicle support platform directly above the lower vehicle support platform.

Abstract: A hydraulic device for a forklift is disclosed. The forklift includes a tilting mast and a fork supported by the mast so that the fork is lifted and lowered. A tilt cylinder operates to tilt the mast by means of oil supplied by a tilt valve. A restricting valve is arranged in an oil passage connecting the tilt cylinder with the tilt valve. When the mast is tilted with the fork carrying an object and located higher than a predetermined reference position, the restricting valve closes the oil passage so that the angle of the tilting mast is limited. A check valve is arranged between the tilt cylinder and the restricting valve. The check valve blocks oil flow from the tilt cylinder to the restricting valve so that the position of the mast is maintained. This prevents unintentional movement of the mast.

Abstract: A lift attached to a truck has a tail gate supported by at least one hydraulic lift and at least one tilt cylinder for respectively lifting the tail gate as a whole and rotating it for opening and closing. A control system for moving such a tail gate up and down as a whole and rotating it to open and close it is provided with a power unit including a hydraulic pump, an electric motor for the hydraulic pump, and a plurality of valves for selectably allowing or not allowing transport of a hydraulic liquid by the hydraulic pump into the hydraulic cylinders, a sensor for measuring the pressure inside the hydraulic pump, external switches, and a controller which includes a CPU, a timer and a semiconductor switch and serves to calculate on real time the speed of the tail gate from signals from the sensor and the timer. The position of the tail gate is accurately determined therefrom and the tail gate is gradually started, accelerated and decelerated to prevent damage to its cargo.

Abstract: This invention includes a brake system for a hydraulic ram or another cylinder, that can be employed as an emergency brake for a lifting elevator. When actuated, the brake arms contact the ram circumferentially to slow and stop the falling ram. The brake arms are preferably lined with an able material that frictionally engages the ram to stop the downward motion of the ram. The brake system may be actuated by loss of hydraulic pressure, by an electronic signal from a hydraulic pressure detector, by down overspeed sensor or by an uncontrolled down motion detector. According to another aspect of the present invention, a controller, which is preferably a programmed control system, compares the actual motion of the elevator as sensed by a detector to a desired motion. Under certain conditions, if the actual motion differs from the desired motion, the controller actuates the brake.

Abstract: A lift attached to a truck has a tail gate supported by at least one hydraulic lift and at least one tilt cylinder for respectively lifting the tail gate as a whole and rotating it for opening and closing. A control system for moving such a tail gate up and down as a whole and rotating it to open and close it is provided with a power unit including a hydraulic pump, an electric motor for the hydraulic pump, and a plurality of valves for selectably allowing or not allowing transport of a hydraulic liquid by the hydraulic pump into the hydraulic cylinders, a sensor for measuring the slope angle of the tail gate, external switches, and a controller which serves to transmit output signals to the motor and to the valves in response to input signals from the sensor and the external switches and is capable of stopping rotary motion of the tail gate at a horizontal position irrespective of the slope of the vehicle and starting and stopping the rotary motion of the tail gate gradually.

Abstract: A speed command signal is applied to a variable voltage, variable frequency controller for driving a three-phase induction motor that operates a positive displacement pump for supplying fluid to a hydraulic elevator drive cylinder. An accelerometer mounted on the car provides an acceleration-related feedback signal to the car speed command input of the motor control, thereby to dampen low frequency resonant modes of the elevator car. A sensor on a check valve between the hydraulic pump and the hydraulic cylinder provides a signal indicative of when the pump pressure is sufficient to support the car load, and the check valve begins to open; the signal is used to memorize ramped-up motor speed at that point, which equals the motor speed necessary to overcome pump leakage in order to support the car. That speed is added into the car speed command at the input of the motor controller to compensate for pump leakage.

Abstract: Process and apparatus for controlling a hydraulic lift wherein with this process, a direct approach to a floor can be achieved without requiring a creeping velocity drive, whereby the car is controlled in a position-dependent manner during the deceleration phase, for the purpose of which a control region is formed which is subdivided into percentage values, the percentage values being retained in tabular form with reference to measured actual position values and upon input of a specific actual position value, the corresponding percentage value is multiplied with the value of the control region (CS) and to this product eventually are added a control deviation (CO) and a pilot control signal (SO) wherein the sum which constitutes the actual control signal used during the deceleration phase, is forwarded to a regulation valve arrangement. An apparatus for carrying out the process is also set forth.

Abstract: A twin post, telescoping jack hydraulic elevator system has a pair of dynamic sensors to determine when the jacks are out of synchronization, by determining any relative differences in height between the two intermediate cylinders. The elevator also includes static sensors to determine if one or both intermediate cylinders are more than a predetermined distance away from their normal positions when the car is stopped at each floor. The controller actuates a resynchronization if the distance between the intermediate jacks exceeds a first threshold, and shuts down the elevator if the distance exceeds a second threshold or if resynchronization demands are issued too often. Preferably, the static sensors are positioned to detect the seal housing at the top of the intermediate cylinder, which projects outwardly from the cylinder.

Abstract: Pneumatic vacuum lift elevator, in which the vertical shaft is a tube with smooth interior surface, preferably cylindrical, with straight axle, and the transport cab or vehicle moving inside such tube is a piston with vertical movement, with minimum play inside the tube, equipped with air suction devices at the upper end of the tube, capable of causing a sufficient pressure differential to displace such piston in controlled ascending and descending movement; completed with an air entry or intake in the lower end of the tube, and the access doors with which the tube is equipped, and which are hermetically closed on the various stopping levels.

Abstract: Water driven robots are provided which can be used for moving different objects at different controlled directions and frequencies to obtain energy and power from the flow of a liquid, such as water. A container (10) contains a siphonic outlet which is capable of converting relatively low continuous flow of water, entering through its inlet (17), to a relatively high intermittent pulsating flow of water, ejected from its outlet (23). Such flow is used for moving the robot as follows: During each cycle, water fills the container so that its weight increases, causing the container to move down and move a pulley (65) or other object (73). When the container's liquid level reaches the inlet of the siphon, it rapidly drains and becomes lighter, thereby resulting in a return of the weight. Thus a continuous inflow of liquid causes the container to oscillate vertically and provides force, energy, and power for operating such robots, for controlling their motion, and for operating work loads connected to the robots.

Abstract: Pneumatic vacuum lift elevator, in which the vertical shaft is a tube with smooth interior surface, preferably cylindrical, with straight axle, and the transport cab or vehicle moving inside such tube is a piston with vertical movement, with minimum play inside the tube, equipped with air suction devices at the upper end of the tube, capable of causing a sufficient pressure differential to displace such piston in controlled ascending and descending movement; completed with an air entry or intake in the lower end of the tube, and the access doors with which the tube is equipped, and which are hermetically closed on the various stopping levels.

Abstract: A passenger lift incorporates an electronic safety interlock to prevent all movement of the lift, until a restraining belt is fastened. In some embodiments, the interlock is a normally open electric switch located inside the restraining belt's buckle. The switch is closed and the movement of the lift actuated only when the restraining belt's matingly interlocking tab is inserted in the buckle.