Patent Description:
Typical governor configurations include a rotating governor mechanism near the top of the hoistway. A governor rope wraps over the rotating governor mechanism and extends down to a governor tension sheave. A weight associated with the tension sheave maintains tension on the governor rope.

The governor rope moves as the elevator car moves and a speed of rotation of the governor mechanism corresponds to the speed of car movement. In high rise buildings it is possible for the governor to have a low frequency response when the elevator car completes a run at certain floors, such as the lower floors in the building. In the event that the governor low frequency response coincides with a frequency response of the elevator car, which may be due to the extended length of the roping suspending the elevator car, any position feedback information provided by the governor may be inaccurate.

<CIT> describes a damping device for suppressing and damping vibratio when a governor roper is vertically oscillated together with a weight. The damping device has a shoe which is elastically brought into contact with a guide frame of a guide mechanism for guiding the vertical movement of the weight by the urging force of a spring. The vibration of the weight is suppressed and damped by the friction force of contact of the show with the guide frame. The entire damping device if arranged in an area of the plane projected area of the weight.

<CIT> describes an elevator governor with a mounting plate fixed to the lower section of a guide rail by a rail clip. A ratchet wheel is provided at the tip of this mounting plate through a shaft. The base end of a lever is fixed to the shaft, and the tip of the lever is inserted into the shaft of a lower tension wheel. The base end of a claw is swingably provided in the lower section of the tip of the mounting plate through a shaft, and the tip of the claw is made to mesh with the claw of a ratchet wheel. When the descending speed of a car exceeds the upper limit value, activating the rope catch of the lower tension wheel, and the lower tension wheel is about to be raised, this state is prevented by the claw whose tip is meshed with the ratchet wheel.

<CIT> describes a safety device of an elevator apparatus which is activated using a force that is generated by a mass body that is generated by a mass body that includes sheaves and a rope, if acceleration of a car reaches an abnormal acceleration set value. A tensioning sheave that can be moved vertically in order to apply tension to the rope is included among the sheaves. A vertical vibration suppressing apparatus that is connected to the tensioning sheave allows vertical displacement of the tensioning sheave during normal operation while also suppressing vertical vibration of the tensioning sheave if the acceleration of the car reaches the abnormal acceleration set value.

According to a first aspect of the present invention an elevator governor is provided in accordance with claim <NUM>.

In some embodiments, the first condition includes a first speed of movement of the tension frame above a threshold speed or a first frequency of movement of the tension frame above a threshold frequency, and the second condition includes a second speed of movement of the tension frame below the threshold speed or a second frequency of movement of the tension frame below the threshold frequency.

In some embodiments, the damper has a damping force that resists the vertical movement of the tension frame, and the damping force changes with a change in a speed of vertical movement of the tension frame.

In some embodiments, the first condition comprises a time during movement of an associated elevator car or within a selected range after completion of movement of the associated elevator car, and the second condition comprises a time while the associated elevator car is stationary and outside the selected range.

In some embodiments, the damper comprises a base and a mounting frame, the mounting frame is configured to be secured to the fixed surface, the mounting frame is configured to resist vertical movement of the base, and the mounting frame is configured to allow for at least some lateral movement of the base relative to the mounting frame.

In some embodiments, wherein the mounting frame is configured to be secured to at least one of a floor surface and a wall surface in a hoistway.

In some embodiments an elevator system is provided, the elevator system including the elevator governor of any of the previous paragraphs, an elevator car; and a governor rope coupled with the elevator car, the governor rope wrapping at least partially around the governor mechanism and the tension sheave, wherein movement of the elevator car causes movement of the governor rope and rotational movement of the governor mechanism.

In some embodiments, the elevator system of the previous paragraph includes a device that determines elevator car movement and wherein the governor provides an additional indication of the elevator car movement.

<FIG> schematically illustrates selected portions of an elevator system <NUM>. An elevator car <NUM> is coupled to a counterweight <NUM> by a plurality of tension members <NUM> that suspend the elevator car <NUM> and counterweight <NUM>. In some embodiments, the tension members <NUM> are round steel ropes. Other embodiments include ropes made of different materials. Still other embodiments include belts as the tension members <NUM>. A traction sheave <NUM> of an elevator machine rotates to cause movement of the tension members <NUM>, which results in desired movement of the elevator car <NUM>.

A governor <NUM> includes a governor mechanism <NUM> and a tension sheave <NUM>. A tension frame <NUM> is coupled with the tension sheave <NUM>. The tension frame <NUM> has a mass that biases the tension sheave <NUM> and the tension frame <NUM> under the influence of gravity. A governor rope <NUM> is coupled to the elevator car <NUM> and arranged in a loop that partially wraps around the governor mechanism <NUM> near a top of the loop and the tension sheave <NUM> near a bottom of the loop.

As the elevator car <NUM> moves vertically, the governor rope <NUM> moves and the governor mechanism <NUM> responsively rotates. The governor mechanism <NUM> is operative to engage a safety brake (not illustrated) in a well-known manner if an overspeed condition exists.

In a high-rise building, the length of the tension members <NUM> tends to allow for some resonance of the elevator system <NUM> that can result in oscillations of the elevator car <NUM> when arriving at a destination floor as schematically represented by the broken lines <NUM>'. Building sway may also contribute to such oscillations. It is possible for such oscillations to cause corresponding movement of the tension sheave <NUM> and tension frame <NUM>. The example governor <NUM> includes a damper <NUM> that is configured to resist vertical movement of the tension frame <NUM> relative to a stationary surface <NUM>, such as a floor or a wall of a hoistway or pit. The damper <NUM> is configured to resist vertical movement of the tension frame <NUM>, and the associated tension sheave <NUM>, under a first condition and to allow for vertical movement of the tension frame <NUM> and the tension sheave <NUM> under a second, different condition.

An example first condition includes oscillations of the elevator car <NUM>, such as at a resonant frequency of the tension members <NUM>. It is undesirable for the tension frame <NUM> to oscillate vertically in response to oscillations of the elevator car <NUM>. The damper <NUM> is configured to resist vertical movement of the tension frame <NUM> under such a first condition.

It is desirable, however, to allow the tension frame <NUM> to move downward slowly over time as the governor rope <NUM> stretches, for example. An example second condition in which the damper <NUM> allows such vertical movement of the tension frame <NUM> includes the elevator car <NUM> remaining stationary.

The damper <NUM> in the example embodiment is configured to provide or impose a damping force that resists vertical movement of the tension frame <NUM> relative to the stationary surface <NUM>. The damping force changes with changes in a speed of vertical movement of the tension frame <NUM>. In some embodiments, the damping force is proportional to a speed with which the tension frame <NUM> tends to move vertically. There are known hydraulic dampers that have such a changing and responsive damping force and some embodiments include such a known damper. Such a changing or responsive damping force allows for slow, downward movement of the tension frame <NUM> over time but resists rapid vertical movement of the tension frame <NUM> during or immediately after a run of the elevator car <NUM> to a destination landing.

The first and second conditions may be defined differently in different embodiments. For example, the first and second condition are defined based on a speed or frequency of movement of the tension frame <NUM>. In some such embodiments, the first condition includes a first speed of movement of the tension frame <NUM> or a first frequency of movement of the tension frame <NUM> above a threshold. The second condition in such embodiments includes a second speed or frequency of movement of the tension frame <NUM> below the threshold.

The first condition in some embodiments is defined based on a time during movement of the elevator car <NUM> or within a selected range after completion of movement of the elevator car <NUM> arriving at a destination landing. Including some time within the selected range after the arrival of the elevator car <NUM> at the destination accounts for oscillations that may occur after such arrival. The, second condition is defined based on a time while the associated elevator car is stationary. The second condition does not include time within the selected range of time included in the first condition.

One aspect of resisting vertical movement of the tension frame <NUM> is maintaining the accuracy or reliability of information provided by the governor mechanism <NUM> to a device <NUM> that monitors or determines elevator car position or movement. The device may be, for example, a portion of the machine or drive used to control movement of the elevator car <NUM>. When the elevator car <NUM> oscillates and the tension frame <NUM> experiences corresponding oscillation, such movement of the tension frame <NUM> tends to be at a lower frequency than that of the elevator car <NUM>. That difference tends to introduce inconsistencies or errors into the position or movement information provided by the governor mechanism <NUM> to the device <NUM>. Resisting vertical movement of the tension frame <NUM> using the damper <NUM> reduces or eliminates such inconsistencies or errors.

The damper <NUM> is also configured to allow for some lateral or side-to-side movement of the tension frame <NUM>. <FIG> schematically illustrates an example arrangement including a mounting frame <NUM> that is configured to be secured to the surface <NUM>, such as the floor of the hoistway or pit. The mounting frame <NUM> includes a recess or cavity <NUM> that accommodates a portion of a base <NUM> of the damper <NUM>. The relative sizes of the recess or cavity <NUM> and the accommodated portion of the base <NUM> allow for some lateral movement of the damper <NUM> while holding the damper <NUM> in a manner that facilitates the damper <NUM> selectively resisting vertical movement of the tension frame <NUM>.

Another configuration is shown in <FIG>. The damper <NUM> includes a coupling <NUM> that secures the damper <NUM> to the tension frame <NUM>. In this example, the coupling <NUM> includes a bushing <NUM> that allows for relative lateral sliding between a bracket or rod <NUM> secured to the tension frame <NUM> and the damper <NUM>.

The disclosed example embodiments provide damping to resist undesirable vertical movement of a governor tension frame <NUM> and tension sheave <NUM>, which avoids undesirable movement of the governor mechanism <NUM>. Reducing or eliminating such undesirable movement provides more reliable or accurate position or movement information from the governor <NUM>, which can be used for monitoring and controlling elevator car movement.

Claim 1:
An elevator governor (<NUM>), comprising:
a rotatable governor mechanism (<NUM>);
a tension sheave (<NUM>);
a tension frame (<NUM>) associated with the tension sheave (<NUM>), the tension frame (<NUM>) having a mass configured to bias the tension frame (<NUM>) and the tension sheave (<NUM>) under an influence of gravity; and
a damper (<NUM>) configured to resist vertical movement of the tension frame (<NUM>) relative to a fixed surface (<NUM>) in a first condition, characterised in that the damper (<NUM>) being further configured to allow vertical movement of the tension frame (<NUM>) relative to the fixed surface in a second, different condition;
wherein the damper (<NUM>) includes a coupling (<NUM>) configured to secure at least one portion of the damper (<NUM>) to the tension frame (<NUM>), and
wherein the coupling (<NUM>) allows for at least some lateral movement of the tension frame (<NUM>) relative to the damper (<NUM>).