Cantilevered climbing elevator

An illustrative example embodiment of an elevator includes an elevator car frame. A drive mechanism is situated near only one side of the elevator car frame. The drive mechanism includes at least one rotatable drive member that is configured to engage a vertical surface near the one side of the elevator car frame, selectively cause movement of the elevator car frame as the rotatable drive member rotates along the vertical surface, and selectively prevent movement of the elevator car frame when the drive member does not rotate relative to the vertical surface. A biasing mechanism urges the rotatable drive member in a direction to engage the vertical surface. At least one stabilizer is situated near the one side of the elevator car frame and is configured to prevent the elevator car frame from tipping away from the vertical surface.

BACKGROUND

Elevator systems have proven useful for carrying passengers among various levels within a building. There are various types of elevator systems. For example, some elevator systems are considered hydraulic and include a piston or cylinder that expands or contracts to cause movement of the elevator car. Other elevator systems are traction-based and include roping between the elevator car and a counterweight. A machine includes a traction sheave that causes movement of the roping to achieve the desired movement and positioning of the elevator car. Hydraulic systems are generally considered useful in buildings that have a few stories while traction systems are typically used in taller buildings.

Each of the known types of elevator systems has features that present challenges for some implementations. For example, although traction elevator systems are useful in taller buildings, in ultra-high rise installations the roping is so long that it introduces appreciable mass and expense. Sag due to roping stretch and bounce of the elevator car are other issues associated with longer roping Additionally, longer roping and taller buildings are more susceptible to sway and drift, each of which requires additional equipment or modification to the elevator system.

SUMMARY

An illustrative example embodiment of an elevator includes an elevator car frame. A drive mechanism is situated near only one side of the elevator car frame. The drive mechanism includes at least one rotatable drive member that is configured to engage a vertical surface near the one side of the elevator car frame, selectively cause movement of the elevator car frame as the rotatable drive member rotates along the vertical surface, and selectively prevent movement of the elevator car frame when the drive member does not rotate relative to the vertical surface. A biasing mechanism urges the rotatable drive member in a direction to engage the vertical surface. At least one stabilizer is situated near the one side of the elevator car frame and is configured to prevent the elevator car frame from tipping away from the vertical surface.

In an embodiment having one or more features of the elevator of the previous paragraph, the at least one rotatable drive member comprises a wheel and a motor supported at least partially within the wheel.

In an embodiment having one or more features of the elevator of any of the previous paragraphs, the at least one rotatable drive member comprises a second wheel.

In an embodiment having one or more features of the elevator of any of the previous paragraphs, the second wheel includes a motor supported at least partially within the second wheel.

In an embodiment having one or more features of the elevator of any of the previous paragraphs, the biasing mechanism comprises at least one beam supported for movement in a first direction to urge the at least one rotatable drive member in the direction to engage the vertical surface and the at least one beam moves in the first direction based upon a force in a second, different direction.

In an embodiment having one or more features of the elevator of any of the previous paragraphs, the first direction is horizontal and the second direction is vertical.

In an embodiment having one or more features of the elevator of any of the previous paragraphs, the force is based on a load on the elevator car frame.

In an embodiment having one or more features of the elevator of any of the previous paragraphs, the at least one rotatable drive member comprises two drive wheels situated to engage oppositely facing vertical surfaces, the at least one beam comprise two beams, each of the two beams has a first end and a second end, the beams are respectively associated with one of the drive wheels, the beams are supported for pivotal movement relative to the elevator car frame in response to the force, the first ends of the beams move toward each other in response to an increase in the force, and the second ends of the beams move away from each other in response to the increase in the force.

In an embodiment having one or more features of the elevator of any of the previous paragraphs, the biasing mechanism includes an actuator portion that moves in the second direction in response to a change in the force, the actuator portion moves in response to the increase in the force to cause movement of the first ends of the beams toward each other, and the actuator portion moves in response to a decrease in the force to allow movement of the first ends of the beams away from each other.

In an embodiment having one or more features of the elevator of any of the previous paragraphs, the actuator portion moves along the second direction.

In an embodiment having one or more features of the elevator of any of the previous paragraphs, the actuator portion includes an angled surface that has a first profile along a portion of the angled surface and a second profile along a second portion of the angled surface, the first profile includes a first angle that is steeper than a second angle of the second portion, and the second portion of the angled surface causes movement of the first ends of the beams in response to the force being above a preselected threshold.

In an embodiment having one or more features of the elevator of any of the previous paragraphs, the second profile includes a curved surface.

In an embodiment having one or more features of the elevator of any of the previous paragraphs and comprising a vertical support member that includes the vertical surface, the vertical support member includes at least one reaction surface that is transverse to the vertical surface; and the stabilizer is received against the at least one reaction surface.

In an embodiment having one or more features of the elevator of any of the previous paragraphs, the vertical support comprises an I-beam having a web and a flange at each end of the web, the web defines the vertical surface, and at least one of the flanges defines the at least one reaction surface.

In an embodiment having one or more features of the elevator of any of the previous paragraphs, the stabilizer comprises at least one roller that is received against the at least one reaction surface on the at least one of the flanges.

An embodiment having one or more features of the elevator of any of the previous paragraphs includes a cabin supported on the elevator car frame, a sensor that provides an output indicating a load in the elevator car, and a processor that determines the load in the elevator car based on the output of the sensor. The biasing mechanism comprises an actuator that is controlled by the processor to change a force for urging the at least one rotatable drive member in the direction to engage the vertical surface based on a change in the load in the elevator car.

In an embodiment having one or more features of the elevator of any of the previous paragraphs, the actuator increases the force for urging the at least one rotatable drive member in the direction to engage the vertical surface based on an increase in the load in the elevator car and decreases the force for urging the at least one rotatable drive member in the direction to engage the vertical surface based on a decrease in the load in the elevator car.

The various features and advantages of at least one disclosed example embodiment will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows.

DETAILED DESCRIPTION

FIG. 1schematically illustrates selected portions of an elevator system20. An elevator car frame22supports a cab24. A drive mechanism26is supported by the elevator car frame22. An elevator controller (not illustrated) controls operation of the drive mechanism26to move or park the elevator car frame22and cab24as needed to provide elevator service to passengers. The drive mechanism26includes at least one rotatable drive member28that is configured to engage a vertical surface. The rotatable drive member28selectively causes vertical movement of the elevator car frame22and the cab24as the rotatable drive member28rotates and moves along the vertical surface. The rotatable drive member28maintains a desired vertical position of the elevator car frame22when the rotatable drive member28remains stationary and does not rotate. As can be seen inFIG. 2, for example, the illustrated example embodiment includes two rotatable drive members28.

In the illustrated example embodiment, the drive mechanism26and the rotatable drive members28are situated near the bottom of the elevator car frame22. This arrangement takes advantage of the structural rigidity at the lower portion of an elevator car frame.

The example embodiment includes a structural member30in the form of an I-beam that includes a web32and flanges34. The web32defines a vertical surface that the rotatable drive members28engage. In the illustrated example embodiment, the rotatable drive members28engage opposite sides of the web32. The rotatable drive members28engage the web32with sufficient force to achieve traction for controlling vertical movement and position of the elevator car frame22and the cab24.

In the illustrated example embodiment, the structural member30is secured by mounting brackets36to one side of a hoistway38. Other embodiments include a structural member that is made as part of the hoistway38or a corresponding portion of the building in which the elevator system20is installed. There are a variety of ways of providing a vertical surface32that can be engaged by one or more rotatable drive members28for purposes of propelling and supporting the elevator car frame22and cab24.

The drive mechanism26is situated on only one side of the elevator car frame22. This results in a cantilevered arrangement of the elevator car frame22. A stabilizer40is provided near the one side of the elevator car frame22to prevent the elevator car frame22from tipping away from the structural member30. In this example, the stabilizer40includes at least one roller that engages a surface on at least one of the flanges34of the I-beam structural member30. In some embodiments, the stabilizer40includes rollers configured like guide rollers on known elevator systems.

FIG. 3illustrates an example rotatable drive member28. A wheel or tire42provides the engagement surface for engaging the vertical surface32to achieve sufficient traction for controlling movement of the elevator car frame22. A motor44in this example embodiment is situated within the rotatable drive member28, which provides a compact arrangement of components that is capable of achieving the necessary torque to cause desired movement and stable positioning of the elevator car frame22based on engagement with the vertical surface32.

FIG. 4schematically illustrates a biasing mechanism50that urges the rotatable drive members28into engagement with the example vertical surface32. The biasing mechanism50includes beams52that are associated with drive member supports54. In this example, the drive member supports54and the beams52are situated for pivotal movement relative to the elevator car frame22(FIG. 1) about pivots56. In this example, first ends of the beams52are situated near the drive member supports54while second ends of the beams52are distal from the rotatable drive members28.

At least one actuator60selectively changes a distance D between the second ends of the beams52to change the engagement force FNwith which the rotatable drive members28engage the vertical surfaces of the web32of the I-beam structural member30. The actuator60changes the distance D in response to a change in a load in the elevator cab24. The load in the cab24imposes a downward force FL. The actuator60urges the rotatable drive members28in a direction to engage the vertical surfaces on the web32of the I-beam structural member30. In the illustrated example embodiment, the movement of the beams52is in a first direction, which is horizontal, and the force associated with the load in the elevator cab24is in a second direction, which is vertical. In the illustrated example embodiment, the first direction is perpendicular to the second direction.

The actuator60facilitates changing the amount of engagement force or normal force FNto accommodate differences in load in the elevator car24. Such an arrangement facilitates maintaining adequate traction between the drive mechanism26and the structural member30without maintaining forces or conditions that would tend to introduce additional wear on the components of the drive mechanism26or the structural member30, for example.

FIG. 5illustrates an example arrangement of an actuator60. In this example, a wedge-shaped actuator portion62moves in response to the force FLcaused by the load in the elevator cab24. Downward movement (according to the drawing) of the wedge-shaped actuator portion62causes sideways and outward movement (according to the drawing) of intermediate members64against the bias of springs66. As the intermediate members64move outward, they urge the nearby second ends of the beams52to spread apart increasing the distance D shown inFIG. 4.

In this example embodiment, the wedge-shaped actuator portion62engages a ramped surface68on the intermediate members64. The outer surface of the actuator portion62and the ramped surfaces68are coated with a low friction material in some embodiments. The wedge-shaped actuator portion62includes an angled surface that has a first profile70along a portion of the angled surface and a second profile72along another portion of the angled surface. The first profile70includes a steeper angle than an angle of the second profile72. Additionally, the second profile72includes a curvature. The second profile72reduces the frictional load associated with engaging the angled surfaces68as the force FLincreases. The second profile72compensates for an increase in the co-efficient of friction by reducing the effect of the normal force at the interface of the second profile72and the angled surfaces68under higher loads in the elevator cab24.

As can be appreciated fromFIGS. 4 and 5, as the force FLincreases, the actuator60increases the distance D, which results in the rotatable drive members28moving toward the vertical surfaces on the web32of the I-beam structural member30. In other words, the actuator60increases the engagement force between the rotatable drive members28and the vertical surfaces32based upon an increase in the load in the elevator cab24. An increased engagement force provides the appropriate amount of traction for achieving desired movement of the elevator car frame22and for parking the cab24at a desired landing.

As shown inFIG. 4, a counterbalancing mechanism80provides a bias for urging the beams52back toward a default position corresponding to a minimum amount of normal force FNapplied by the rotatable drive members28to the vertical surfaces32. the minimum normal force FNis useful for conditions such as an empty elevator cab24. As the load in the elevator cab24decreases, a spring74(FIG. 5) urges the wedge-shaped actuator portion62in an upward direction (according to the drawing). Under those conditions, the counterbalancing mechanism80urges the first ends of the beams52apart and decreases the distance D between the second ends of the beams52.

FIG. 6schematically illustrates another example embodiment in which a sensor90provides an output indicating the load in the elevator car24to a processor92. An actuator94, such as an electric linear actuator, changes a position of the rotatable drive members28relative to the structural members30as schematically shown by the arrows96to alter the engagement force based on changes in the load as indicated by the sensor90. The processor92controls the actuator94to achieve a desired engagement force corresponding to the current load in the elevator car24.

The illustrated example embodiments include various features that can be advantageous. For example, situating the drive mechanism26on only one side of the elevator car frame22leaves more room in the hoistway38to accommodate a larger sized elevator cab24or a variety of car configurations. Additionally, it is possible to position a door100(FIG. 2) of the elevator car on any of the three remaining sides of the elevator cab24other than the one that the drive mechanism26is situated near. In addition to utilizing hoistway space more efficiently, less material is required with a drive mechanism near only one side of the elevator car frame. Reducing the required amount of materials reduces the costs of an elevator system.

Other features of example embodiments include reduced installation time, which is due for example to the requirement for only one structural member on only one side of the elevator car. Additionally, the structural member may be more strategically placed where load rated attachment points are more easily or more effectively accommodated inside the hoistway.

Another feature of example embodiments is that it becomes more straightforward to incorporate more than one elevator car in a single hoistway. Multiple cars can use the same structural member without complicated arrangements to avoid interference between the operative components of the drive mechanisms for each car. Some embodiments include the ability to transfer elevator cars among different hoistways. The United States Patent Application Publications US 2109/0077636 and US 2109/0077637 each show ways of transferring elevator cars among hoistways and having more than one car in a hoistway. The teachings of those two published applications are incorporated by reference into this description.