HK1237754A1 - Counterweight for elevator system - Google Patents

Description

Counterweight for elevator system

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. provisional patent application No. 62/043,133, filed on 8/28/2014, which is incorporated herein by reference in its entirety.

Background

Embodiments of the present invention relate to elevator systems and, more particularly, to an elevator system having an asymmetric counterweight.

Vertical travel of the elevator car is typically powered by a drive assembly that may be supported within an upper portion of the elevator hoistway by a support member, such as a floor. The drive assembly typically includes a traction machine consisting of a gearless motor and a traction sheave that can both be mounted on the surface of the bedplate. The rotational torque generated by the motor is used to drive the traction sheave. Depending on the direction of rotation of the motor, the traction sheave causes the tension members to raise or lower the elevator car and counterweight vertically through the hoistway.

In conventional elevator systems, the counterweight is usually placed directly behind the elevator car, centered on the elevator car or on one side of the elevator car. However, older elevator systems may have an asymmetrical layout, where the counterweight is generally not centered with respect to the car. The modernization of these old elevator systems is time consuming and requires the relocation of the counterweight, which is costly.

Brief description of the invention

According to one embodiment of the invention, a counterweight is provided that includes a counterweight frame including a crosshead. A counterweight hitch (pitch) is operably coupled to the counterweight frame. The counterweight hitch includes a vertically stacked first sheave channel and a second sheave channel. Each of the first and second pulley channels includes an internal cavity within which at least one individual pulley assembly is mounted. The plurality of individual sheave assemblies are substantially identical and arranged at an angle relative to a center plane of the counterweight frame.

Additionally or alternatively, the invention may incorporate one or more of the following features, either alone or in various combinations:

-each of the plurality of individual pulley assemblies is connected to one of the first and second pulley channels by a fastener;

-adjacent individual pulley assemblies are inserted between the first and second pulley channels;

-at least one spring pin is configured to limit the rotation of each individual sheave assembly relative to the center plane of the counterweight frame.

-the counterweight hitch is coupled to a crosshead of the counterweight frame.

The counterweight hitch extends through an opening at the top of the counterweight frame;

-the counterweight hitch extends around the outside of the top of the counterweight frame; and

-the first pulley channel and the second pulley channel are coupled with at least one vertical upright (upright).

In accordance with another embodiment of the present invention, an elevator system is provided that includes a hoistway and a car coupled with at least one car guide rail for movement within the hoistway. The counterweight is coupled with at least one counterweight guide rail for movement in the hoistway. The counterweight and the at least one counterweight guide rail are offset from a center of the car. The counterweight includes a counterweight frame having a crosshead. The counterweight hitch is operably coupled to the counterweight frame. The counterweight hitch includes a vertically stacked first sheave channel and a second sheave channel. Each of the first and second pulley channels includes an internal cavity within which at least one individual pulley assembly is mounted. The plurality of individual sheave assemblies are substantially identical and arranged at an angle relative to a center plane of the counterweight frame. A plurality of tension members operatively couple the car and the counterweight. Each tension member is disposed around one of the plurality of individual sheaves of the counterweight hitch. The drive machine is configured to engage a plurality of tension members to move the car and the counterweight within the hoistway.

Additionally or alternatively, the invention may incorporate one or more of the following features, either alone or in various combinations:

-each of the plurality of individual pulley assemblies is connected to one of the first and second pulley channels by a fastener;

-adjacent individual pulley assemblies are inserted between the first and second pulley channels;

-at least one spring pin configured to limit rotation of each individual sheave assembly relative to a center plane of the counterweight frame;

-the counterweight hitch is coupled to a crosshead of the counterweight frame;

the counterweight hitch extends through an opening at the top of the counterweight frame; and

the counterweight hitch extends around the outside of the top of the counterweight frame.

Brief description of the drawings

The invention has been particularly pointed out and distinctly claimed in the concluding portion of the specification. The above and other features and advantages of the present invention will be apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:

fig. 1 is a perspective view of an example of an elevator system;

fig. 2 is a front view of an example counterweight assembly according to an embodiment of the invention;

fig. 3 is a perspective view of a counterweight hitch of the counterweight assembly according to an embodiment of the present invention;

fig. 3a is a side view of the counterweight assembly of fig. 3;

fig. 4 is a perspective view of another counterweight hitch of the counterweight assembly according to an embodiment of the present invention;

fig. 5 is a perspective view of another counterweight hitch of the counterweight assembly according to an embodiment of the present invention;

fig. 6 is a perspective view of a separate sheave assembly configured for use in a counterweight hitch, according to an embodiment of the present invention;

fig. 6a is a side view of the individual sheave assembly of fig. 6.

The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.

Detailed description of the invention

Referring now to fig. 1, an exemplary elevator system 20 is shown. The elevator system 20 includes an elevator car 24 configured to move vertically upward and downward within the hoistway 22 along a plurality of car guide rails 26. Guide assemblies mounted to the top and bottom of the elevator car 24 are configured to engage the car guide rails 26 to maintain proper alignment of the elevator car 24 as the elevator car 24 moves within the hoistway 22.

The elevator system 20 also includes a counterweight 28 configured to move vertically upward and downward within the hoistway 22. The counterweight 28 moves in a direction generally opposite to the movement of the elevator car 24 as is known in conventional elevator systems. Movement of the counterweight 28 is guided by counterweight guide rails 30 mounted within the hoistway 22. In the illustrated non-limiting embodiment, the elevator car 24 and counterweight 28 include sheave assemblies 32, 34 that cooperate with at least one tension member 36 and a traction sheave 38 mounted to a drive machine 40 to raise and lower the elevator car 24. The drive machine 40 in the illustrated embodiment of the invention is adapted and sized for use with a flat tension member 36. The sheave assembly 32 shown in fig. 1 is mounted to the top of the elevator car 24. However, the sheave assembly 32 may be mounted at another location on the elevator car 24, such as, for example, the bottom of the elevator car 24, or elsewhere in the system 20 as recognized by those skilled in the art.

The drive machine 40 of the elevator system 20 is disposed and supported in an installed position atop a support member 42, such as a floor, e.g., in a portion of the hoistway 22 or machine room. Although the elevator system 20 shown and described herein has an over-hung 2: 1 roping arrangement, elevator systems 20 having other roping arrangements and hoistway layouts are within the scope of the present invention.

In some embodiments, the counterweight 28 of the elevator system 10 is asymmetric, meaning that the counterweight guide rails 30 and the counterweight 28 movable within the guide rails 30 are arranged substantially offset from the center of the elevator car 24 and car guide rails 26 within the hoistway 22.

Referring now to fig. 2, an example of the counterweight 28 is shown in more detail. As shown, the counterweight 28 is an assembly including a generally rectangular frame 50, such as, for example, comprised of a plurality of connected metal members. A plurality of weights 52 are placed within the frame 50, the plurality of weights being arranged in a stacked configuration. Guide assemblies 54 configured to cooperate with the counterweight guide rails 30 are secured adjacent opposite sides of the counterweight frame 50. The counterweight hitch 60 is connected to the upper portion 56 of the counterweight frame 50, which is also known as a crosshead. The plurality of tension members 36 are operably coupled to the counterweight hitch 60 such that movement of the tension members 36 via the drive machine 40 causes the counterweight 28 to move within the hoistway 22 along the counterweight guide rails 30.

Referring now to fig. 3-5, the counterweight hitch 60 is provided in more detail. The counterweight hitch 60 includes a first pulley channel 62a and a second pulley channel 62b disposed vertically below the first pulley channel 62 a. The first and second pulley channels 62a, 62b are substantially identical in shape and size and may be formed from bent or welded metal. Adjacent end surfaces 64a, 64b of the first and second pulley channels 62a, 62b are coupled by first and second posts 66, respectively. In the non-limiting embodiment shown, the post 66 is a C-shaped or U-shaped channel secured (such as, for example, by bolts) to each pulley channel 62.

A connection assembly 70 extending from each upright 66 is configured to couple the counterweight hitch 60 and the counterweight frame 50. The configuration of the connection assembly 70 may vary depending on the structure of the counterweight frame 50, and more particularly, depending on the structure of the counterweight cross head 56. In the embodiment shown in fig. 3, the connection assembly 70 includes a first connection member 72 mounted to the first side 68 of the post 66 and a second connection member 74 mounted to the second, opposite side 69 of the post 66 (see fig. 3 a). In one embodiment, the first and second connecting members 72, 74 may be integrally formed. The first and second connecting members 72, 74 generally extend outwardly from the upright 66 to increase the depth of the counterweight hitch 60 beyond the depth of the counterweight frame 50. The counterweight hitch 60 generally extends through the central opening 58 in the top of the frame 50 such that the upper surfaces 76 of the first and second connecting members 72, 74 contact and engage the adjacent surfaces of the cross head 56.

In the embodiment shown in fig. 4, the connection assembly 70 includes a support frame 80 that extends vertically downward from a first rail 82 and a second rail (not shown) mounted to the first and second uprights 66. The support frame 80 is configured to extend through the central opening 58 in the top of the counterweight frame 50 such that the base 84 of the support frame 80 is directly below the crosshead 56. The base 84 of the support frame 80 includes a first connecting member 72 and a second connecting member (not shown) configured to contact the support frame 80 and operatively couple it to the counterweight cross-head 56, thus coupling the counterweight hitch 60 to the counterweight cross-head 56. In the non-limiting embodiment shown, the first and second connecting members 72, 74 are integrally formed as a curved channel.

The connection assembly 70 shown in fig. 5 is intended for a counterweight 28 having a solid and/or narrow counterweight frame 50. A thin first connecting member 72 is mounted to the first side 68 of the post 66 and a substantially identical second connecting member 74 is mounted to the second opposite side 69 of the post 66. In one embodiment, the first and second connecting members 72, 74 are formed from sheet metal. In the non-limiting embodiment shown, the connecting members 72, 74 are T-shaped and have an elongated central portion that extends vertically downward around the exterior of the counterweight frame 50. One or more fasteners 88 couple the free ends 86 of the central portions of the first and second connecting members 72, 74. Because the free end 86 is disposed just below the crosshead 56, the at least one fastener 88 is configured to contact and engage the crosshead 56 such that the counterweight frame 50 and the hitch 60 move together through the hoistway 22.

Referring again to fig. 2, each of the pulley channels 62a, 62b is configured to define an interior cavity 90 in which at least one individual pulley assembly 100 is seated (best shown in fig. 6). The number of individual pulley assemblies 100 mounted to each pulley channel 62a, 62b depends on the total number of tension members 36 in the elevator system 20. Adjacent tension members 36 are received by individual pulley assemblies 100 that alternate between the first and second pulley channels 62a, 62 b. For example, in an elevator system 20 having five tension members 36, the end and center tension members 36 are received around a separate pulley assembly 100 mounted to the first pulley channel 62a, and the second and fourth tension members 36 are received by a pulley assembly 100 mounted to the second pulley channel 62 b.

The individual sheave assemblies 100 are substantially identical and are each configured to receive a single tension member 36 of the elevator system 20. Examples of individual sheave assemblies 100 are shown in fig. 6 and 6 a. In the non-limiting embodiment shown, the individual pulley assembly 100 includes a pulley 102 mounted to an adjacent support 104 such that the pulley 102 is configured to rotate about an axis of rotation X. A bracket 106 connected to the support 104 is configured to operatively couple the pulley assembly 100 within the interior cavity 90 of the pulley channels 62a, 62b with the fastener 108 such that the pulley assembly 100 is generally rotatable about an axis Y defined by the fastener 108.

Each of the individual pulley assemblies 100 is mounted to the pulley channels 62a, 62b of the counterweight hitch 60 at an angle relative to a center plane C (see fig. 3a) of the counterweight frame 50. The angle of each individual sheave assembly 100 is substantially the same and is determined based on the asymmetry of the counterweight 28 within the hoistway 22. At least one spring pin 110 is used to bias each individual sheave assembly 100 to a desired angle to prevent the sheave assemblies 100 from rotating during operation of the elevator system 20. In addition, a complementary angled slot 112 is formed in each of the pulley channels 62a, 62b to receive the tension member 36 about the pulley assembly 100.

By mounting the individual sheave assemblies 100 at an angle relative to the center plane C of the counterweight frame 50, the tension members 36 can connect the asymmetrical counterweight 28 and elevator car 24 without requiring one or more twists. This results in improved tracking and extends the life of the tension members 36.

While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.

Claims (15)

1. A counterweight, comprising:

a counterweight frame including a crosshead; and

a counterweight hitch operably coupled to the counterweight frame, the counterweight hitch including a first pulley channel and a second pulley channel vertically connected by a first upright and a second upright, each of the first pulley channel and the second pulley channel including an internal cavity within which at least one individual pulley assembly is mounted, the plurality of individual pulley assemblies being substantially identical and arranged at an angle relative to a center plane of the counterweight frame.

2. The counterweight according to claim 1, wherein each of the plurality of individual sheave assemblies is connected to one of the first sheave channel and the second sheave channel by a fastener.

3. The counterweight according to claim 1, wherein adjacent individual sheave assemblies are interposed between the first sheave channel and the second sheave channel.

4. The counterweight according to claim 1, wherein at least one spring pin is configured to limit rotation of each individual sheave assembly relative to the center plane of the counterweight frame.

5. The counterweight according to claim 1, wherein the counterweight hitch is coupled to the crosshead of the counterweight frame.

6. The counterweight according to claim 5, wherein the counterweight hitch extends through an opening at a top of the counterweight frame.

7. The counterweight according to claim 5, wherein the counterweight hitch extends around an exterior of a top portion of the counterweight frame.

8. The counterweight according to claim 1, wherein the first sheave channel and the second sheave channel are coupled with at least one vertical column.

9. An elevator system, comprising:

a hoistway having a machine room disposed at a first end;

a car coupled with at least one car guide rail for movement in the hoistway;

a counterweight coupled with at least one counterweight guide rail for movement in the hoistway, the counterweight and the at least one counterweight guide rail being offset from a center of the car, the counterweight comprising:

a counterweight frame including a crosshead; and

a counterweight hitch operably coupled to the counterweight frame, the counterweight hitch including a first pulley channel and a second pulley channel vertically connected by a first upright and a second upright, each of the first pulley channel and the second pulley channel including an internal cavity within which at least one individual pulley assembly is mounted, the plurality of individual pulley assemblies being substantially identical and arranged at an angle relative to a center plane of the counterweight frame;

a plurality of tension members operably coupling the car and the counterweight, each of the plurality of tension members disposed about one of the plurality of individual sheaves of the counterweight hitch; and

a drive machine configured to engage the plurality of tension members to move the car and the counterweight within the hoistway.

10. The elevator system according to claim 9, wherein each of the plurality of separate sheave assemblies is connected to one of the first sheave channel and the second sheave channel by a fastener.

11. The elevator system according to claim 9, wherein adjacent separate sheave assemblies are interposed between the first sheave channel and the second sheave channel.

12. The elevator system according to claim 9, wherein at least one spring pin is configured to limit rotation of each individual sheave assembly relative to the center plane of the counterweight frame.

13. The elevator system according to claim 9, wherein the counterweight hitch is coupled to the crosshead of the counterweight frame.

14. The elevator system according to claim 13, wherein the counterweight hitch extends through an opening at a top of the counterweight frame.

15. The elevator system according to claim 13, wherein the counterweight hitch extends around an exterior of a top portion of the counterweight frame.