Otis Elevator Company

Other

Young S Yoo

John K Salmon

Eric K Jamieson

Richard C McCarthy

Joseph C Walker

Joseph R Faust

Breffni X Baggot

Keith Worsley

Rudi Steger

A hitch assembly is disclosed for an elevator car suspended by hoist ropes and driven by a drive sheave. The hitch assembly having a hitch plate with openings for thimble rods, wherein geometrical planes bisecting the openings for the thimble rods are substantially coplanar with geometrical planes bisecting hoist rope grooved recesses in the drive sheave. Another feature of the present invention is a vibration isolation assembly for fastening the hitch plate to a mounting plate fixed to the elevator car, wherein the vibration isolation assembly isolates vibrations transmitted to the elevator car from the hoist ropes. Still another feature of the hitch assembly is a rope tension equalization assembly for fastening the hoist ropes to the hitch plate, wherein the rope tension equalization assembly equalizes tensions among the hoist ropes.

Elevator car hitch

An elevator having a car suspended by a rope in a 2:1 roping arrangement has a sheave for receiving the ropes and a structure for rotatably supporting the sheave. A flexible member is used to attach the structure to a car, which minimizes the transference of moments from the structure to the car. In addition, a damping material is used in mounting the flexible member to the car and support structure which reduces vibration and noise transmissions. Springs are also placed at the top and bottom of the flexible member to isolate low frequency vibrations in the vertical direction.

Flexible elevator hitch

The invention obtains the weight of an elevator car in a manner which is minimally dependent on the distribution of the load within the cab by means of a load cell and support sandwiched between a first and second plate, the load being shared between the load cell and support. Threaded rods pass through the first and second plates, as well as through a space between the first and second plates, and further pass through hitch springs and support the car. The upper ends of the rods are connected to the hoist ropes. The load weighing apparatus further includes a pair of rod positioners which keep constant the lateral displacement of the rods one from another. The load cell and support are not enclosed by the rods, yielding the further advantage that a mechanic has easy access to the load cell for its maintenance.

Elevator load-weighing at car hitch

A magnet 34 is mounted to a linkage 30 which passes vertically over a conductive vane 32 which extends the entire length of the elevator hoistway 46. Eddy currents induced in the conductive vane 32 as the magnet 34 passes over the conductive vane 32 cause a reaction force on the magnet 34 and the linkage 30. The reaction force causes the safety 26 or 28 to contact a guide rail 22 on which an elevator car 10 is riding, thereby braking the elevator car 10 at any point in the hoistway between the terminals and eliminating the need for a governor. The vane width 50 is large at the terminals as compared to the middle of the hoistway 46 which increases the reaction force at the terminals. The invention eliminates the need for a governor.

Bidirectional eddy current overspeed protection for elevators

The position of the elevator cab in an elevator system is detected by sensing the location of the cab relative to a flexible graduated tape whose ends are fixed in the elevator hoistway. The tape is provided with detectable components which are spaced a predetermined distance apart on the tape. Sensors are fixed on the elevator cab assembly adjacent to the tape so that the sensors can detect each of the tape components as the elevator cab moves up and down in the hoistway. Guides are mounted on the cab assembly to engage the tape so as to ensure that the tape and sensors are properly positioned relative to each other so that the tape components will be detected by the sensors. The guides are mounted on leaf or blade springs so as to be able to move relative to the cab assembly in response to tape deflections and correct the tape deflections to guide the tape past the sensors without creating a significant amount of noise.

Elevator cab position sensing with reduced operating noise

A single load cell 10 both (A) measures the load on a elevator hitch providing an analog elevator load signal on line 11 to an analog-to-digital converter 20 via line 18, for providing a digital elevator load signal and (B) is used for providing a dynamic tare of elevator load weighing system for calibrating the analog-to-digital converter 20 by adjusting an analog reference voltage (V.sub.ref) until the digital elevator load signal is equal to the dynamic tare.

Recalibration of hitch load weighing using dynamic tare

A stopped plate is provided in the overhead area in an elevator hoistway above the uppermost landing in the building. The stopping plate is mounted in the hoistway and is operable to stop upward movement of the elevator cab and counterweight without impacting the main components of the cab or counterweight. In one embodiment of the invention, there is provided a pair of inverted safeties mounted on the stopping plate and guide rails. If the cab rises above the uppermost landing, the safeties will be set by the cab contacting the stopping plate, thereby limiting further upward motion of the cab. In a second embodiment of the invention, the traction cables are provided with motion arresters such as enlarged clamps, which are secured to the cables a preset distance above the cab assembly. The cables pass through restricted openings in the stopping plate, which openings will not allow passage of the motion arresters. Motion of the traction cables is thus arrested when the cable clamps encounter the stopping plate.

Stopping of elevators in the up direction

A permanent magnet 54 mounted on rods 41 passes vertically over a conductive plate 56 in an elevator hoistway 36, a reactive force causes movement of the permanent magnet 54 vertically away from the conductive plate 56 so that a wedge 24 secured to the rods 41 moves within a tapered wedge guide 44 until it contacts an elevator guide rail 14 on which an elevator car 2 is riding, thereby braking the elevator car 2.

Positive terminal overspeed protection by rail grabbing

The cab or counterweight pit buffer for an elevator system includes a cross beam disposed in the pit below the ground floor landing for the elevator. The cross beam is mounted on the cab or counterweight guide rails by means of safety brakes which will allow limited and controlled downward movement of the cross beam when a downwardly directed force is exerted on it. The cross beam carries at least one plunger-type spring or oil buffer on its upper surface for initial engagement with the cab or counterweight in the event the latter must be stopped by the pit buffer. The majority of the braking force for the descending cab or counterweight is provided by the safety brakes on the buffer cross beam. The buffer assembly is particularly adapted for high speed elevator systems.

Pit buffer assembly for high speed elevators

An encoder is connected to an elevator traction machine shaft for sensing rotation of the machine shaft. The connector assembly includes a flexible torque-transmitting rod to minimize lateral deflection forces imparted to the encoder shaft by reason of misalignment between the machine and encoder shafts. A flexible collar is used to interconnect the flexible torque-transmitting rod with the encoder shaft.

Elevator drive motor to encoder connection having a flexible rod and a

An elevator pit buffer assembly includes a pair of pistons which are mounted in the pit outboard of each side of the cab and counterweight. Each of the buffer pistons is equipped with a sheave joined at the upper end thereof. Ropes are reeved about each buffer sheave pair and extend between the sheaves in each pair beneath the bottom of the cab and counterweight. The ends of each of the buffer ropes are dead-hitched to the floor or wall of the pit.

One to two stroke roped elevator pit buffers

An elevator cable hitch plate is isolated for the cab frame crosshead by an elastomeric pad and a mounting plate bolted to the crosshead is disposed between the pad and the crosshead. A stabilizer bracket is fixed to the mounting plate and to the hitch plate. The bracket allows limited vertical movement of the mounting plate and hitch plate relative to each other, but prevents lateral sliding movement therebetween. The bracket thus prevents the hoist cable thimble rods from contacting the edges of the holes in the plates through which the thimble rods pass. Minimal cable-induced vibration and noise is thus produced during operation of the elevator.

Noise and vibration reduction at elevator cab hitch

The invention weighs an elevator car independently of variations in load distribution within the car and variations in the tension distribution in rods and ropes from which the car is suspended. This is accomplished by means of a top hitch plate, a middle hitch plate, and a bottom hitch plate, which are arranged such that the bottom hitch plate has a pivot 16 mounted on it with the middle hitch plate being mounted on the pivot 16 and a load cell and a support being mounted on the middle hitch plate 17 outboard of the rods from which the car 2 is supported. The top hitch plate is connected to a crosshead at its upper surface. The load cell and support bear against the top hitch plate when there is tension in the rods from the weight of the car 2.

Pivot mount of elevator load-weighing at car hitch

A car door seal, comprising a brush, is utilized to seal the openings between a closed car door and an elevator car and to minimize backlash between the car doors and the car. By utilizing a brush, such uneven openings are effectively sealed because the brushes bend for narrower openings between the car door and the car. The brush also provides an effective damping and spring force between the door and the car. As a result, door rattle, caused by backlash and aerodynamically induced vibration loads during car travel, is minimized thereby minimizing vibration and noise within the interior of the car.

Elevator noise minimizer

Air deflectors are mounted on the top and bottom of the counterweight assembly in an elevator system to deflect air in the elevator hoistway to the sides of the counterweight as the latter moves up and down in the hoistway. The deflectors ensure that air turbulence is not directed toward the car as the car and counterweight pass each other in the hoistway. A quieter and smoother passenger ride is thus accomplished. In an ultra high-speed elevator system, the counterweights may be completely enclosed in an aerodynamic jacket. Cable connections and compensating rope connections to the counterweight are all made inboard thereof to ensure that the counterweight is free of turbulence-inducing protuberances.

Growing community of inventors

Avon, CT, United States of America

Young S Yoo