HK1181026B - Integrated elevator safety system - Google Patents

Description

Integrated elevator safety system

Technical Field

The present application relates to a device for stopping an elevator car and an elevator system with an integrated emergency stop device.

Background

A typical elevator system includes an elevator car attached to a counterweight by ropes. The elevator motor and brake work together to move the elevator car and counterweight up and down the hoistway to transport passengers or cargo from one floor to another. An elevator drive and controller provide power to and control operation of the elevator system.

Elevators also typically include a safety system to prevent the elevator from traveling at excessive speeds in response to elevator components breaking or otherwise becoming inoperable. Traditionally, elevator safety systems include a mechanical speed sensing device, commonly referred to as an overspeed governor, a tensioning device, and a safety gear for selectively frictionally engaging elevator guide rails. Overspeed governors are traditionally mounted in the machine room or in the top of the hoistway. A safety system is mounted in the car and a tensioner, typically a rope or other linkage, connects the system with the governor. When the governor detects a dangerous situation due to an excessively high travel speed, it sends a signal to the safety gear through the tensioning device. The safety gear then engages the guide rail and stops the elevator car.

Disclosure of Invention

An arrangement for stopping an elevator car traveling up or down guide rails mounted in a hoistway includes a chassis mounted on one side of the car and an overspeed governor, a guiding device and a safety gear mounted on the chassis. The overspeed governor detects when car overspeed occurs. The guide device guides the elevator car along the guide rail. The safety gear is vertically aligned with the guide on the chassis and stops the elevator car by frictionally engaging elevator guide rails that pass through a through slot formed in each of the safety gear and the guide. When the overspeed governor detects that car overspeed is occurring, the safety gear causes the elevator car to stop by frictionally engaging the guide rails.

Drawings

Fig. 1A is a perspective view of an elevator system with an integrated safety device according to the present invention.

Fig. 1B is a front view of the elevator of fig. 1A showing an integrated safety device.

Fig. 2A is a perspective view of a first base of the integrated safety device.

FIG. 2B is a perspective view of the first base of the integrated safety device with the cover on the overspeed governor.

Fig. 3A-3B are front and rear views, respectively, of the overspeed governor of fig. 2A when an overspeed condition is not occurring.

Fig. 4A-4B are front and rear views, respectively, of the overspeed governor of fig. 2A while an overspeed state is occurring.

FIG. 5 is a perspective view of a second base of the integrated safety device of FIG. 1B.

Detailed Description

Fig. 1A is a perspective view of an elevator system with an integrated safety device according to an embodiment of the present invention. Fig. 1B is a front view of the elevator of fig. 1A with an integrated safety device. Elevator system 10 includes elevator car 12, guide rails 14a, 14b, and integrated safety device 16. The integrated safety device 16 includes: a first chassis 18a attached to one side of car 12; a second chassis 18b attached to the other side of car 12; and a connecting rod 19 extending between the first seat 18a and the second seat 18 b.

First pedestal 18a is bolted to one side of elevator car 12 and aligned with guide rails 14a, and second pedestal 18b is bolted to the other side of elevator car 12 and aligned with guide rails 14 b. The governor rope R is anchored to the top and bottom of the hoistway and passes through the first pedestal 18 a. Connecting rod 19 is connected to first pedestal 18a and second pedestal 18b and may be located above the ceiling of a passenger in elevator car 12 (but not above car 12).

Elevator car 12 travels on guide rails 14a, 14b or is slidably or rollably connected to guide rails 14a, 14b and travels inside a hoistway (not shown). Both bases 18a, 18b act as guides to keep car 12 slidably or rollably connected to the guide rails. Both chassis 18a, 18b also act as a safety device to stop car 12 in an overspeed condition. First chassis 18a acts as the primary chassis, detecting when an overspeed condition occurs, and is used to stop car 12. A connecting rod 19 mechanically links the first chassis 18a to the second chassis 18b such that the second chassis 18b is used to stop the car 12 when the first chassis 18a is used to stop the car 12 in an emergency or when an overspeed occurs.

Fig. 2A is a perspective view of first chassis 18a of integrated safety device 16. First chassis 18a includes overspeed governor 20 (which includes tripping sheave 22, governor tripping mechanism 23, idler sheave 24, overspeed switch 26, and free wheeling disc 28), first guiding device 29a with channel 30a, first safety gear 31a with channel 32a and roller 33a, first safety lever 34a, and stabilizing device 36 a. Also shown in fig. 2A are the adjuster cord R and the connecting rod 19.

The first chassis 18a may be sheet metal and include holes for fastening the first chassis 18a to the elevator car and holes for attaching the overspeed governor 20, the first guiding device 29a and the first safety gear 31a (and other parts) thereto. Governor tripping mechanism 23 is attached to tripping sheave 22, and tripping sheave 22 is rotatably mounted to first base 18 a. Governor tripping mechanism 23 is made of plastic to reduce the noise of overspeed governor 20. Idler sheave 24 of overspeed governor 20 is also rotatably mounted to first chassis 18a at a location below trip sheave 22. Overspeed switch 26 is attached to first chassis 18 a. Governor rope R is anchored at the top and bottom of the elevator hoistway (see fig. 1A) and travels around tripping sheave 22 and idler sheave 24. First guiding device 29a is attached to first chassis 18a and aligned relative to first guide rail 14a such that guide rail 14a slides through channel 30a of guiding device 29a as the elevator car moves up and down in the hoistway. Although a sliding guide is shown, the first guide 29a may be a roller guide. First safety gear 3la is attached to first chassis 18a and aligned with respect to first guide 29a such that guide rail 14a may pass through channel 30a of guide 29a and through channel 32a of safety gear 31a, and such that roller 33a may properly engage guide rail 14a in an overspeed or emergency condition, as described in further detail below. The through slot 32a includes a roller 33a on one side. First safety lever 34a is connected to free wheeling disc 28 of governor tripping mechanism 23. When an overspeed condition occurs, free wheeling disc 28 is coupled to governor tripping mechanism 23 via rollers 50a-50c (as described in more detail below with reference to fig. 3A-4B). First safety lever 34a is also connected to first safety mechanism 31 a. Stabilizing device 36a is connected to first safety lever 34a to stabilize first safety lever 34a when an overspeed is not occurring (and therefore free wheeling disc 28 and first safety lever 34a are not coupled to governor tripping mechanism 23). In this embodiment, stabilizer 36a is a spring that biases first safety lever 34a toward stabilizer 36 a. Connecting rod 19 connects first safety lever 34a to second safety lever 34B on second chassis 18B on the other side of the car (see fig. 1B, 5).

The first safety gear 31a (together with the second safety gear 31b, shown in fig. 5) acts as a final emergency device to stop the elevator car 12. As described above, the guide rail 14a passes through the through groove 32a of the safety mechanism 31 a. Car 12 stops when guide rail 14a is frictionally engaged by rollers 33a of safety gear 31a such that the guide rail is connected to rollers 33a and the side of through slot 32a opposite the rollers. This connection or frictional engagement is due to movement of roller 33a into channel 32a toward guide rail 14a, which is caused by movement of first safety lever 34a triggered by an overspeed condition.

The first guiding device 29a guides the elevator car along the guide rails 14a in the hoistway (see fig. 1A), with the guide rails 14a passing through the through slots 30a, as described above.

Overspeed governor 20 is used to detect an overspeed condition of the elevator car. Governor rope R is statically anchored at the top and bottom of the hoistway (see fig. 1A) and replicates car speed to overspeed governor 20 by looping around tripping sheave 22 and idler sheave 24. The ropes R from the top of the hoistway pass under idler sheave 24, pass around and over tripping sheave 22, and then travel down to the anchorage at the bottom of the hoistway. This configuration ensures that tripping sheave 22 and idler sheave 24 rotate. Governor tripping mechanism 23 rotates about the same axis as tripping sheave 22 and includes a mass and a mass support coupled together. The operation of governor tripping mechanism 23 is discussed in further detail below in conjunction with fig. 3A-4B. When trip sheave 22 rotates (due to governor rope R) at an angular velocity within a defined range, the mass remains coupled and governor tripping mechanism 23 rotates with trip sheave 22 without engaging over-speed switch 26 or free wheeling disc 28. Governor tripping mechanism 23 is actuated when the force of the coupled mass is overcome at the set angular velocity of tripping sheave 22. In particular, when the centrifugal force on the mass exceeds the force created by the coupling, the mass support moves radially outward depending on the angular velocity, tripping overspeed switch 26 and engaging free-wheeling disc 28 (attached to first safety lever 34a), thereby coupling it to governor tripping mechanism 23.

When overspeed switch 26 is tripped, elevator power is cut off. When free wheeling disc 28 is coupled to governor tripping mechanism 23, it moves with governor tripping mechanism 23 (which is moving with tripping sheave 22). First safety lever 34a is attached to free wheeling disc 28 and therefore also moves with free wheeling disc 28 and governor tripping mechanism 23 when free wheeling disc 28 is coupled to governor tripping mechanism 23 (in an overspeed condition). This counterclockwise rotational movement of first safety lever 34a overcomes the force of stabilizer 36a holding lever 34a in a certain position. The counter-clockwise rotation (in mm) of the safety lever in turn causes the rollers 33a inside the first safety gear 31a to move towards the guide rail 14a in the through slot 32a, thereby frictionally engaging the guide rail 14a and stopping the elevator car. When an overspeed condition does not occur, i.e., during normal elevator operation, free wheeling disc 28 is not coupled to governor tripping mechanism 23 and first safety lever 34a is held in place by stabilizing device 36 a. In the illustrative embodiment of fig. 2A, the stabilizing device 36a is a spring (but may be any suitable type of stabilizing device, such as a solenoid). Stabilizer 36a operates to prevent false tripping of first safety lever 34a (thereby preventing engagement of first safety gear 31a when overspeed does not occur).

As shown in fig. 1B and 2A, the connecting rod 19 connects the first safety lever 34 on one end to the second safety gear 31B on the other end (on the second seat 18B). In particular, connecting rod 19 is used to transfer the rotational movement of first safety lever 34a to second safety lever 34b of second safety gear 31b attached to second chassis 18b when engaged (when an overspeed condition occurs).

FIG. 2B is a perspective view of the first base of the integrated safety device with the cover on the overspeed governor. Fig. 2B shows first chassis 18a with cover 38 on the overspeed governor, governor rope R, first guiding device 29a with channel 30a, first safety gear 31a with channel 32a and roller 33a, first safety lever 34a, and stabilizing device 36 a.

Cover 38 is attached to first chassis 18a and covers overspeed governor 20 to protect it. This protection of the overspeed governor by the cover 38 is particularly useful, for example, when the building is being constructed and the elevator is used before being closed and protected by the hoistway. Cover 38 is typically sheet metal, but may be any other material that will provide protection to overspeed governor 20 and is not overly heavy for mounting on first chassis 18 a.

FIG. 3A is a front view of the overspeed governor and safety lever of FIG. 2A when an overspeed condition is not occurring. FIG. 3B is a rear view of the overspeed governor and safety lever of FIG. 3A. FIGS. 3A-3B show: a governor tripping mechanism 23 having a rotational axis 40, a first mass 42a, a second mass 42b, a third mass 42c, a first mass support 44a, a second mass support 44b, a third mass support 44c, a first link 46a, a second link 46b, a third link 46c, a first pivot point 48a, a second pivot point 48b, a third pivot point 48c, a first roller 50a, a second roller 50b, a third roller 50 c; first safety lever 34 a; and a free wheeling disc 28.

Overspeed governor tripping mechanism 23 rotates counterclockwise about tripping sheave axis of rotation 40 and includes a first mass 42a, a second mass 42b, a third mass 42c, a first mass support 44a, a second mass support 44b, and a third mass support 44 c. The first mass 42a is attached to a first mass support 44 a. The second mass 42b is attached to the second mass support 44 b. The third mass 42c is attached to a third mass support 44 c. The first mass support 44a is pivotably attached to the trip sheave 22 (shown in fig. 2A) at a first mass support pivot point 48 a. The second mass support 44b is pivotally attached to the trip pulley 22 at a second mass support pivot point 48 b. The third mass support 44c is pivotally attached to the trip pulley 22 at a third mass support pivot point 48 c. The first mass support 44a is pivotably attached to the second mass support 44b by a second link 46b, the second link 46b including a second roller 50 b. The second mass support 44b is pivotably attached to the third mass support 44c by a third link 46c, the third link 46c including a roller 50 c. The third mass support 44c is pivotably attached to the first mass support 44a by a first link 46a, the first link 46a including a roller 50 a.

Governor tripping mechanism 23 also includes a releasable non-elastic coupling (not shown) between one of the mass supports 44a, 44b, 44c and trip sheave 22 or between two of the mass supports that limits the centrifugal force generated by the rotation of the sheave (not shown). For example, the coupler may be a magnet, as shown in FIG. 5 of U.S. patent application No. 2010/0059319, which is incorporated herein by reference. When the sheave rotates at an angular velocity within a defined range, the coupler holds the coupled members together, and governor tripping mechanism 23 rotates with tripping sheave 22. When the force provided by the coupling is overcome by centrifugal forces on the masses 42a, 42b, and 42c at a set angular velocity of the trip sheave 22, the governor tripping mechanism 23 is actuated, causing the masses 42a, 42b, 42c and supports 44a, 44b, 44c to move radially outward.

FIG. 4A shows a front view of the overspeed governor of FIG. 3A while overspeed is occurring. FIG. 4B shows a rear view of the overspeed governor of FIG. 4A. FIGS. 4A-4B show: a governor tripping mechanism 23 having a rotational axis 40, a first mass 42a, a second mass 42b, a third mass 42c, a first mass support 44a, a second mass support 44b, a third mass support 44c, a first link 46a, a second link 46b, a third link 46c, a first pivot point 48a, a second pivot point 48b, a third pivot point 48c, a first roller 50a, a second roller 50b, a third roller 50 c; first safety lever 34 a; and a free wheeling disc 28.

As described above, when overspeed occurs, the force of the coupling (not shown) holding the masses 42a, 42b, and 42c together is overcome, and the masses 42a, 42b, and 42c and the supports 44a, 44b, and 44c move radially outward depending on the angular velocity. When the masses 42a, 42b, 42c and the supports 44a, 44b, 44c move radially outward, the first link 46a, the second link 46b, and the third link 46c move due to their respective connections with the supports 44a, 44b, 44 c. This movement of the links 46a, 46b, 46c causes the rollers 50a, 50b, 50c to contact the free wheeling disc 28. The contact of roller 50 with disk 28 couples free wheeling disk 28 to governor tripping mechanism 23. Once it is coupled to governor tripping mechanism 23, free wheeling disc 28 moves with it. First safety lever 34a attached to free wheeling disc 28 also moves, engaging first safety mechanism 31a (see fig. 2A and 2B).

The governor mechanism 23 connecting the masses 42A, 42b, 42c, supports 44a, 44b, 44c and links 46a, 46b, 46c to form a generally circular shape defines the movement of the mass supports 44a, 44b, 44c such that when in an un-actuated state, the mass supports 44a, 44b, 44c are radially spaced about the pulley axis of rotation 40 and when actuated, the mass supports 44a, 44b, 44c move radially outward depending on angular velocity to form a generally circular circumference until the outer arcuate edges of the mass supports 44a, 44b, 44c trip the overspeed switch 26 (fig. 2A) and the rollers 50a, 50b, 50c of links 46a, 46b, 46c move radially inward and engage the free wheeling disc 28. When the overspeed switch 26 is engaged, the elevator power is cut off. Because governor tripping mechanism 23 forms a substantially continuous circle at the outer edges of mass supports 44a, 44b, 44c and provides the controlled motion previously described, once governor tripping mechanism 23 is actuated it will trip overspeed switch 26 and engage free wheeling disc 28 almost immediately regardless of angular position.

The overspeed governor of fig. 3A-4B is shown for exemplary purposes only. Different types of overspeed governor can be used to detect an overspeed condition and engage the safety lever, which causes the safety lever(s) to stop the elevator car.

Fig. 5 shows second chassis 18b of integrated safety device 16 according to an embodiment of the present invention, and includes second guide 29b with channel 30b, second safety gear 31b with channel 32b, second safety bar 34b, second stabilizing device 36b, and connecting rod 19. Second chassis 18b may be sheet metal and include holes for securing chassis 18b to the elevator car on the opposite side wall of car 12 than first chassis 18a, and holes for attaching second guide 29b, second safety gear 31b, and second safety bar 34b to chassis 18 b. Second guiding device 29B is attached to second chassis 18B and aligned relative to second rail 14B (shown in fig. 1B) such that rail 14B can pass through channel 30B of second guiding device 29B. Although a sliding guide is shown, the second guide 29b may also be a roller guide. Second safety gear 31b is attached to second chassis 18b and aligned with respect to second guiding device 29b such that rail 14b passes through channel 32b of second safety gear 31b and through channel 30b of second guiding device 29 b. The second safety lever 34b is connected to the second safety gear 31b and to the connecting rod 19. Connecting rod 19 may pass over the car ceiling to connect first safety bar 34a on first chassis 18a to end 60 of second safety bar 34b on second chassis 18 b.

The second guiding device 29B guides the elevator car along the second guide rail 14B in the hoistway (see fig. 1B), and the guide rail 14B passes through the through slot 30B, as described above. The second guiding device 29b also helps to ensure that the second safety gear 31b is properly aligned with the second guide rail 14b that also passes through the channel 32b of the second safety gear 31b so that the second safety gear 31b frictionally engages the second elevator guide rail 14b to help stop the elevator car in an emergency. Connecting rod 19 mechanically links second safety lever 34b (at end 60) to first safety lever 34a (as shown in fig. 2A). When an overspeed is detected and free wheeling disc 28 and first safety lever 34a are both coupled to governor tripping mechanism 23, first safety lever 34a moves, causing roller 33a of first safety mechanism 31a to frictionally engage guide rail 14a, as described above. Second safety lever 34b, which is connected to first safety lever 34a by connecting rod 19, also moves, causing rollers (not shown) in second safety gear 31b to move into channel 32b and frictionally engage rail 14 b. The frictional engagement of the rollers of the second safety gear 31b to the rail 14b is performed in the same manner as described with respect to the frictional engagement of the rollers 33a of the first safety gear 31a to the rail 14a (fig. 2A). When overspeed does not occur, stabilizing device 36b is connected to second safety lever 34b to stabilize second safety lever 34 b. In this embodiment, stabilizer 36b is a spring that biases second safety lever 34b toward stabilizer 36 b.

Second chassis 18b with second guide 29b, second safety gear 31b and second safety lever 34b assists first chassis 18a in stopping the elevator car when an overspeed condition is detected. Because connecting rod 19 mechanically links second safety lever 34b to first safety lever 34a such that when first safety gear 31a frictionally engages first rail 14a (in an overspeed condition), second safety lever 34b causes second safety gear 31b to frictionally engage rail 14b, the need for overspeed governor 20 on second chassis 18b to detect when an overspeed occurs is eliminated. The inclusion of second chassis 18b on the opposite side of elevator car 12 from first chassis 18a helps the car to stop more smoothly and efficiently in an emergency situation (than if only first chassis 18a were present on elevator car 12).

The inclusion of the first chassis 18a with the overspeed governor 20, the first guide 29a, the first safety gear 31a and the first safety lever 34a, the second chassis 18b with the second guide 29b, the second safety gear 31b and the second safety lever 34b, and the connecting rod 19 connecting the first safety lever 34a and the second safety lever 34b provides a reliable and compact safety device for the elevator system that is easy to put together and install. First chassis 18a serves as a common mounting reference for all elements attached to first chassis 18a (overspeed governor 20, first guiding device 29a, first safety gear 31a and first safety lever 34 a). Similarly, second chassis 18b acts as a common mounting reference for the elements attached to second chassis 18b (second guide 29b, second safety gear 31b, and second safety lever 34 b). The common mounting datum for each individual base 18a, 18b allows each base 18a, 18b and its parts to be assembled and inspected in the shop. This also ensures that all of the components on each respective pedestal 18a, 18b are properly aligned with respect to each other, thereby reducing additional adjustment and set up time when installing the elevator system.

Furthermore, by positioning overspeed governor 20 on first chassis 18a, it can be directly linked to first safety gear 31a, thereby reducing the delay in activating first safety gear 3la after an overspeed condition is detected. In past elevator systems, the overspeed governor was often installed at the top of the hoistway or in the machine room, requiring the overspeed governor to be tied to the safety gear with a rope, which sometimes caused delays in the activation of the safety gear after detecting an overspeed due to the length and elasticity of the rope. By positioning overspeed governor 20 on first chassis 18a adjacent to first safety gear 31a, they may be directly linked (by first safety lever 34a), thereby reducing the delay in activating first safety gear 31a when an overspeed condition occurs. Second safety gear 31b may also be activated with minimal delay due to the connection of first safety lever 34a and second safety lever 34b via connecting rod 19.

Another important advantage of the integrated elevator safety device 16 is the reduction in space required for the overspeed governor, guidance and safety gear. Heretofore, the overspeed governor, the guiding device and the safety gear have each been mounted separately, taking up space in separate locations (overspeed governor in the hoistway or machine room, guiding device and safety gear on the car). By mounting the overspeed governor, the guiding device and the safety gear on a common first chassis and the second guiding device and the second safety gear on a common second chassis, each chassis being mounted on the elevator car, the amount of space required by the individual safety devices of the elevator in the hoistway is reduced.

Another advantage of the integrated safety device of the present invention is the cost reduction that results from the reduction of space required and the reduction of time for installing the system. The installation of two bases, each with an already aligned and verified safety device, saves the time and effort that would have to be spent installing all separate overspeed governor, guiding device and safety gear, and each properly aligning and joining them together.

While the invention has been described with reference to an exemplary embodiment(s), it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. For example, different types of overspeed governors or different safety levers may be used. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment(s) disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims (23)

1. An apparatus for stopping an elevator car traveling along guide rails installed in a hoistway, the apparatus comprising:

a first chassis mounted on one side of the elevator car;

an overspeed governor mounted on said first chassis for detecting when car overspeed occurs;

a first guide device mounted on the first chassis for guiding the elevator car along a first guide rail;

a first safety mechanism mounted on the first chassis in alignment with the first guide for stopping the elevator car by frictionally engaging the first guide rail when car overspeed is detected by the overspeed governor

A first safety lever connecting the overspeed governor to a first safety gear to cause the first safety gear to frictionally engage the first guide rail when the overspeed governor detects an occurrence of car overspeed;

a second chassis mounted on an opposite side of the elevator car from the first chassis and aligned relative to a second guide rail;

a second guide device mounted on the second chassis for guiding the elevator car along the second guide rail; and

a second safety gear mounted on the second chassis in alignment with the second guide for stopping the elevator car by frictionally engaging the second guide rail when car overspeed is detected by the overspeed governor.

2. The apparatus of claim 1, further comprising:

a first stabilizing device for stabilizing the first safety bar when the elevator is in normal operation.

3. The device of claim 2, wherein the first stabilizing device is one of a spring or a solenoid.

4. The apparatus of claim 1, wherein the second guide is mounted on the second chassis above the second safety gear such that a channel formed in the second guide and a channel formed in the second safety gear are vertically aligned, thereby allowing the second rail to pass through the channels.

5. The apparatus of claim 1, further comprising:

a second safety lever connected to a second safety gear to cause the second safety gear to frictionally engage the second guide rail when the overspeed governor detects the occurrence of car overspeed.

6. The apparatus of claim 5, further comprising:

a connecting rod for connecting the first safety lever to the second safety lever such that when the first safety lever causes a first safety mechanism to frictionally engage the first rail, the second safety lever causes a second safety mechanism to frictionally engage the second rail.

7. The apparatus of claim 6, wherein the connecting bar passes between the first safety lever and the second safety lever above a ceiling in the car.

8. The apparatus of claim 5, further comprising:

a second stabilizing device for stabilizing the second safety bar when the elevator is in normal operation.

9. The device of claim 8, wherein the second stabilizing device is one of a spring or a solenoid.

10. The apparatus of claim 1, wherein the overspeed governor comprises:

a trip sheave rotatably mounted to the first base;

a governor with rollers connected to the trip sheave, the governor configured to increase in diameter due to centrifugal force at an overspeed speed;

an idler sheave rotatably mounted to the first mount;

governor rope wrapped around the trip sheave and the idler sheave and attached to the top and bottom of the hoistway to replicate car speed to the governor;

a trip switch mounted to the first base and actuated when the governor diameter increases and, when actuated, cuts power to the elevator; and

a free wheeling disc attached to the first safety lever, the free wheeling disc coupling the first safety lever to the governor by contact with the roller as the governor increases in diameter due to an overspeed condition.

11. The apparatus of claim 1, wherein the first guide is mounted on the first chassis above the first safety gear such that the channel formed in the first guide and the channel formed in the first safety gear are vertically aligned, thereby allowing the first rail to pass through the channel.

12. The apparatus of claim 1, wherein the overspeed governor is mounted on the first chassis adjacent a first safety gear and the first guiding device.

13. The device of claim 1, wherein the overspeed governor is a centrifugally actuated governor.

14. The device of claim 1, wherein the overspeed governor is made of plastic.

15. The apparatus of claim 1, further comprising:

a cover mounted to the first base to protect the overspeed governor.

16. The apparatus of claim 15, wherein the cover is made of sheet metal.

17. An elevator system with an integrated emergency stop device, the system comprising:

an elevator car traveling up and down first and second guide rails installed in a hoistway;

a first base mounted on one side of the car, the first base having mounted thereon: an overspeed governor for detecting when car overspeed occurs; a first guide device for guiding the elevator car along the first guide rail; a first safety mechanism vertically aligned with the first guide rail stopping the elevator car by frictional engagement with the first guide rail; and a first safety lever connecting the overspeed governor to a first safety gear to cause frictional engagement of the first safety gear with the first guide rail when the overspeed governor detects the occurrence of car overspeed; and

a second chassis mounted on an opposite side of the elevator car, the second chassis having mounted thereon: a second guide device for guiding the elevator car along the second guide rail; a second safety mechanism vertically aligned with the second guide, stopping the elevator car by frictional engagement with a second guide rail; and a second safety lever connecting the first safety mechanism to the second safety mechanism to cause the second safety mechanism to frictionally engage the second guide rail.

18. The system of claim 17, further comprising:

a connecting rod connecting the first safety lever to the second safety lever such that when the first safety lever causes a first safety mechanism to frictionally engage the first rail, the second safety lever causes a second safety mechanism to frictionally engage the second rail.

19. The elevator system of claim 17, wherein the overspeed governor is made of plastic.

20. The elevator system of claim 17, further comprising:

a cover mounted to the first base to protect the overspeed governor.

21. The elevator system of claim 17, further comprising:

a first stabilizing device for stabilizing the first safety bar when the elevator is in normal operation.

22. The elevator system of claim 21, further comprising:

a second stabilizing device for stabilizing the second safety bar when the elevator is in normal operation.

23. The elevator system of claim 22, wherein each stabilizing device is one of a spring and a solenoid.