GB2271544A

GB2271544A - Roping arrangement of a hydraulic elevator.

Info

Publication number: GB2271544A
Application number: GB9320589A
Authority: GB
Inventors: Sung Gyu Park
Original assignee: Goldstar Industrial Systems Co Ltd
Current assignee: LSIS Co Ltd
Priority date: 1992-10-13
Filing date: 1993-10-06
Publication date: 1994-04-20
Anticipated expiration: 2013-10-06
Also published as: KR940010006U; GB9320589D0; KR950004101Y1; GB2271544B

Abstract

A roping arrangement of an underling type hydraulic elevator includes frames 9c, 9b, mounted on front and rear lower surfaces of the cage 1, at least two first pulleys 7, 7a mounted on, and lifted by a hydraulic piston, a second pulley 7b positioned in a support frame 5 for a hydraulic cylinder 6 four pulleys 7c', 7d', 7c'', 7d'' provided for the frames such that they are mounted on opposite ends of the cage frames, 9c 9b, respectively. A pulley support beam 20 having a pair of spaced pulleys 21, 21a is positioned above the hydraulic cylinder 6. A lifting rope 11 extends from the frame 5 to an upper beam (12) of an elevator well via the pulleys in order to one, 7, of the first pulleys, the second pulley 7b, the other first pulley, 7a, the pulleys 7c of the rear frame, the pulleys 21, 21a, of the beam 20, and the pulleys 7d, of the front frame. Extension of the piston lifts the elevator cage. <IMAGE>

Description

ROPING MECHANISM OF HYDRAULIC ELEVATOR BACKGROUND OF THE INVENTION Field of the Invention The present invention relates in general to a roping mechanism of a hydraulic elevator, and more particularly to a structural improvement of the roping mechanism for prevention of interference between elements of a lower part of an elevator cage as well as prevention of impartment of an eccentric load on the cage.

Description of the Prior Art Conventionally, hydraulic elevators are classified into two types, that is, a fork type elevator and an under-sling type elevator, in accordance with their installation styles.

In the fork type elevator, a lifting mechanism for lifting an elevator cage is positioned at the upper top of the cage and lifts the cage by hydraulic power generated by a hydraulic cylinder positioned above the elevator cage. It is noted that this fork type elevator is suitable for lifting a light load not more than 1000 Kg. On the other hand, in the under-sling type elevator, a roping mechanism for lifting the elevator cage is positioned at a side of the cage and lifts the cage by a hydraulic force generated by its hydraulic cylinder, and suitable for lifting a heavy load higher than 1000 Kg. This under-sling type elevator is concerned in the present invention.

With reference to Figs. 1 to 3, there is shown an undersling type elevator in accordance with the prior art. In this under-sling type elevator, an elevator cage 1 is supported by both guide rails 2 and 8 and a rail bracket 3. A pair of buffer springs 4 and buffers are placed on a pit located below the elevator cage 1. The elevator further includes a jack die 5 which is mounted on the pit at a side of the cage 1.

A hydraulic cylinder 6 is mounted on the jack die 5 and coupled to a pair of opposed pulleys 7 and 7a by its piston so as to cooperate with the pulleys 7 and 7a. The elevator also includes frames 9 and 10 which are provided under the elevator cage 1. The jack die 5 is provided at its lower space with a pulley 7b while the frame 10 is provided with a pair of pulleys 7c and 7d. A lifting rope 11 is coupled to the jack die 5 at an end thereof and wraps the pulleys in an order of 7, 7b, 7a, 7c and 7d prior to coupling of the other end thereof to an upper beam 12 placed at an upper section of an elevator well for the elevator.

In operation of the above under-sling type elevator, the hydraulic cylinder 6 is applied with a fluid under pressure and causes its piston to ascend in order to lift the pair of opposed pulleys 7 and 7a connected to the upper top of the piston, so that the rope 11 wrapping about the pulleys is tensed and pulled toward the pulleys 7 and 7a in an amount proportional to the lifting distance of the piston of the cylinder 6. The pulled rope 11 lifts the pulleys 7b, 7c and 7d, thus to lift the elevator cage 1.

Here, the rope 11 is wrapped about the cylinder-side pulleys four times totally while it is wrapped about the cageside pulleys two times totally. In this regard, when the piston of the cylinder 6 ascends by 10 mm height, the elevator cage 1 is lifted by 20 mm height, and this roping type is named as a 2 : 4 roping.

However, such a prior art under-sling type elevator has a problem that when it is installed in a narrow well, the position of the hydraulic cylinder 6 should be shifted from its desired position to the front position in order for provision of a space for the guide rails1 thus to inevitably cause the elevator cage 1 to be imparted with an eccentric load.

In addition, even an installation of the prior art undersling type elevator in a relatively wider well causes another problem due to the lower frame 9 positioned at an inclination angle. Otherwise stated, this under-sling type elevator results in an interference between the frame 9 and the lower frame 10 of the elevator cage 1. This inclined position of the frame 9 also causes an interference between the frame 9 and both a sling wedge and a guide shoe, both the sling wedge and the guide shoe being mounted on the lower frame 10. The interfering sections of the frame 9 are thus cut off in order to remove the interference, but this cutoff of the interfering sections of the frame weakens the strength of the elevator.

A further problem of the prior art under-sling type elevator is caused by an elevator cage having a narrow width.

That is, when the under-sling type elevator has the elevator cage having the narrow width, the buffer springs 4 are placed between the pulleys 7c and 7d, between which the rope 11 extends, such that there occurs an interference between the buffer springs 4 and the rope 11 extending between the pulleys 7c and 7d. In order to prevent the interference between the buffer springs 4 and rope 11, the buffer springs 4 should be positioned on another places. However, since the frame 9 is positioned at the inclination angle as described above, the another place for the buffer springs 4 is scarcely provided.

SUMMARY OF THE INVENTION It is, therefore, an object of the present invention to provide a roping mechanism of a hydraulic elevator in which the aforementioned problems can be overcome and which is changeable in a fixing position of an end of a lifting rope and provided with a plurality of frames mounted on individual positions in order to easily adjust a distance between the frames1 thus to achieve a desired installation of the elevator without imparting an eccentric load on an elevator cage even in the case of installation of the elevator in a narrow well and to reliably prevent an interference between the elements of a lower part of the elevator cage.

In order to accomplish the above object, a roping mechanism of a hydraulic elevator according to a preferred embodiment of the present invention comprising an elevator cage, a jack die placed on a pit at a side of the cage, and a hydraulic cylinder supported on the jack die and generating a hydraulic force to be transmitted to the elevator cage by a rope, further comprising: first and second frames mounted on a front lower surface and on a rear lower surface of the elevator cage, respectively; at least two first pulleys mounted on an upper top of a piston of the hydraulic cylinder and lifted by the piston; a second pulley positioned in the jack die and connected to the first pulleys by the rope; a pair of third pulleys provided at the second frame such that they are mounted on opposite ends of the second frame; a pair of fourth pulleys provided at the first frame such that they are mounted on opposite ends of the first frame; a pulley support beam having a pair of fifth pulleys spaced out by a predetermined distance, the beam being positioned above the hydraulic cylinder; and the rope connected at an end thereof to a fixture of the jack die and at the other end thereof to a fixture beam of an upper section of an elevator well through the pulleys in order of one of the first pulleys, the second pulley, the other first pulley, the third pulleys, the fifth pulleys and the fourth pulleys, whereby the rope is pulled toward the first and second pulleys when the first pulleys are lifted by the piston of the cylinder, thus to lift the elevator cage.

In accordance with another embodiment of the present invention, the first pulleys comprise four pulleys and the second pulley comprises three pulleys, and the rope between the fixture of the jack die and the third pulleys alternately wraps about the first and second pulleys, thus to achieve a 4 : 8 roping.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: Fig. 1 is a front view of an under-sling type hydraulic elevator in accordance with the prior art; Fig. 2 is a side view of the prior art under-sling type elevator of Fig. 1; Fig. 3 is a plan view of the prior art under-sling type elevator of Fig. 1; Fig. 4 is a front view of an under-sling type hydraulic elevator having a roping mechanism of a 4::4 roping in accordance with a primary embodiment of the present invention; Fig. 5 is a side view of the under-sling type elevator of Fig. 4; Fig. 6 is a plan view of the under-sling type elevator of Fig. 4; Fig. 7 is a plan view of cylinder-side pulleys of a roping mechanism of an under-sling type hydraulic elevator in accordance with a second alternate embodiment of the present invention for achieving a 4:8 roping; and Fig. 8 is a front view of the cylinder-side pulleys of Fig. 7.

DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference to Figs. 4 to 6, there is shown an undersling type hydraulic elevator having a roping mechanism in accordance with a primary embodiment of the present invention.

In this under-sling type elevator, an elevator cage 1 is supported by guide rails 2 and a rail bracket 3. A jack die 5 is mounted on a pit at a side of the cage 1 and supports a hydraulic cylinder 6 which is coupled to both a guide rail 8 and the rail bracket 3. This hydraulic cylinder 6 is also coupled to a pair of opposed pulleys 7 and 7a by its piston.

The jack die 5 is provided at its lower space with a pulley 7b.

The elevator also includes frames 9a, 9b and 10 which are placed under the cage 1. The frames 9a and 9b are mounted on a front lower surface of cage 1 and on a rear lower surface of the cage 1, respectively. These frame 9a and 9b are also provided with four pulleys 7c', 7d', 7c" and 7d" such that the two pulleys 7c', 7d' and the other pulleys 7c" and 7d are parallel to the frames 9a and 9b, respectively. A pair of buffer springs 4 are placed on a pit below the cage 1.

A pulley support beam 20, on which a pair of pulleys 21 and 21a are rotatably supported such that they are spaced out by a predetermined distance, is laterally arranged in and fixedly mounted on an upper section of an elevator well above the pair of opposed pulleys 7 and 7a of the cylinder 6.

A rope 11 is coupled to the jack die 5 at an end thereof and wraps the pulleys 7, 7b, 7a, 7d, 7c", 21a, 21, 7c' and 7d' prior to coupling of the other end thereof to a fixture of an upper beam 12.

In operation of the above under-sling type elevator, the piston of the hydraulic cylinder 6 ascends to lift the pair of opposed pulleys 7 and 7a, so that the rope 11 wrapping about the pulleys 7b, 7d, 7c, 21a, 21, 7c' and 7d' is tensed and pulled toward the pulleys 7, 7a and 7b, and lifts the pulleys 7c', 7d', 7c" and 7d of the frames 9a and 9b, thus to lift the elevator cage 1. At this time, the rope 11 wraps the pulleys in an order of 7 - > 7b - > 7a - > 7d" - > 7c" - > 21a - > 21 - > 7c' - > 7d', so that the power transmission for lifting the elevator cage 1 by the rope 11 is achieved by the above order of pulleys.

Here, the rope 11 is wrapped about the cylinder-side pulleys and about the cage-side pulleys four times, respectively. In this regard, when the piston of the cylinder 6 ascends by 10 mm, the elevator cage 1 is lifted by 10 mm, and the above roping type is named as a 4 : 4 roping. In the present invention, in order to achieve the same velocity ratio as that achieved by the conventional 2 : 4 roping, the roping type should become 4 : 8 roping.

Figs. 7 and 8 show cylinder-side pulleys of a roping mechanism of an under-sling type hydraulic elevator in accordance with a second alternate embodiment of the present invention for achieving the 4 : 8 roping.

In this second alternate embodiment, four pulleys 7, 7a, 7' and 7a' are coupled to the hydraulic cylinder 6 while three pulleys 7b, 7b' and 7b are provided in the lower space of the jack die 5. In this case, the rope 11 between the fixture of the jack die 5 and the pulley 7d alternately wraps about the four pulleys 7, 7a, 7' and 7a' and the three pulleys 7b, 7b' and 7'. Hence, the order of power transmissio.l by the rope 11 through the pulleys of this second alternate embodiment is 7 > 7b - > 7a - > 7b' - > 7' - > 7b' - > 7a' - > 7d" - > 7c - > 21a - > 21 - > 7c' - > 7d'.

As described above, in a roping mechanism of a hydraulic elevator in accordance with the present invention, any frame is not positioned to be inclined, so that no interference occurs between the elements of a lower part of the elevator cage and a fixing position of a lifting rope can be easily changed when the elevator is installed in a narrow well. The elevator cage is provided with a pair of frames which are positioned on a front lower surface and on a rear lower surface of the elevator cage, thus to be imparted with no eccentric load.

Another advantage of the present invention is resided in that even when the elevator cage has a narrow width, an interference between buffer springs and a lifting rope can be reliably prevented since the distance between the opposed frames positioned under the cage is easily adjusted.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope of the invention as disclosed in the accompanying claims.

Claims

WHAT IS CLAIMED IS:

1. A roping mechanism of a hydraulic elevator comprising an elevator cage, a jack die placed on a pit at a side of said cage7 and a hydraulic cylinder supported on said jack die and generating a hydraulic force to be transmitted to said elevator cage by a rope, further comprising: first and second frames mounted on a front lower surface and on a rear lower surface of said elevator cage, respectively; at least two first pulleys mounted on an upper top of a piston of said hydraulic cylinder and lifted by said piston; a second pulley positioned in said jack die and connected to said first pulleys by said rope; a pair of third pulleys provided at said second frame such that they are mounted on opposite ends of said second frame; a pair of fourth pulleys provided at said first frame such that they are mounted on opposite ends of said first frame;; a pulley support beam having a pair of fifth pulleys spaced out by a predetermined distance, said beam being positioned above said hydraulic cylinder; and said rope connected at an end thereof to a fixture of said jack die and at the other end thereof to a fixture beam of an upper section of an elevator well through said pulleys in order of one of said first pulleys, said second pulley, the other first pulley1 said third pulleys, said fifth pulleys and said fourth pulleys, whereby said rope is pulled toward said first and second pulleys when said first pulleys are lifted by said piston of the cylinder, thus to lift said elevator cage.

2. The roping mechanism according to claim 1, wherein said first pulleys comprise four pulleys and said second pulley comprises three pulleys, and the rope between said fixture of the jack die and said third pulleys alternately wraps about said first and second pulleys, thus to achieve a 4 : 8 roping.

3. A roping mechanism of a hydraulic elevator substantially as herein described with reference to Figures 4 to 6, or Figures 7 and 8, of the accompanying drawings.