GB2034280A

GB2034280A - Elevator Catch Gear

Info

Publication number: GB2034280A
Application number: GB7938240A
Authority: GB
Original assignee: Rhodes & Partners Ltd H
Current assignee: Rhodes & Partners Ltd H
Priority date: 1978-11-10
Filing date: 1979-11-05
Publication date: 1980-06-04

Abstract

An elevator installation comprising side walls (14) and an elevator (16) raisable and lowerable between the side walls, the installation including a catching station, and catch gear comprising a plurality of catching devices each having a rotatable pinion (13) and a chain (12) mounted one on the side walls at the catching station and the other on the elevator, each pinion rotatably and positively engaging the corresponding chain as the elevator passes upwardly through the catching station, and means such as a one-way clutch (38), Fig. 3, not shown, substantially preventing opposite rotation of each member, so that the catch gear prevents substantial downward motion of the elevator. <IMAGE>

Description

SPECIFICATION Elevator Catch Gear This invention relates to elevator catch gear, i.e. to apparatus for catching an upwardly moving body to prevent the body from falling again.

In particular, the invention is useful in a mine shaft for catching a cage, which has been carried too far by the winding mechanism. In such instances, apparatus is provided to detach the cage from the winding mechanism and the head gear includes catch gear to catch and hold the released cage. Known catch gear permits the cage to decelerate to a stop and then catches the cage as it falls. Clearly, such gear should operate with a minimum of fall of the cage to minimise shock to the occupants of the cage and also to minimise shock-loading on the cage and the head gear supporting structure. One such known catch gear relies on the rack and pawl principle, using spring-urged elements to the rack. These springs, however, may fail.

The present invention provides elevator catch gear for catching an upwardly moving body at a given location, the catch gear comprising a member rotatable in one angular direction and a track positively engageabie by the member, during relative movement between the member and the track in one direction, the member and the track being provided one on the body and the other at said given location, and means substantially preventing rotation of the member in the opposite angular direction, whereby the member is held by the track.

The invention may reside in an elevator installation comprising side walls and an elevator raisable and lowerable between the side walls, the installation including a catching station, and catch gear comprising a plurality of catching devices each having a rotatable member and a track mounted one on the side walls at the catching station and the other on the elevator, each member rotatably and positively engaging the corresponding track as the elevator passes upwardly through the catching station, and means substantially preventing opposite rotation of each member, so that the catch gear prevents substantial return downward motion of the elevator.

The invention may reside in a mine shaft installation including a cage raisable in the shaft, a winding mechanism attached to the cage, means to detach the cage from the winding mechanism on over-run of the cage in the upward direction, and catch gear to catch the released cage, the catch gear being constructed as described above.

Preferably, the track is a chain and the member is a pinion, the latter being provided on the elevator (or cage). The track may be in the form of a chain.

This arrangement permits the catch gear to be simply constructed and ensures that once the members have engaged with the track, they remain in engagement, no reliance being put on springs. Where a chain is used, this may be a commercially available component, as may the pinion and other components.

Reference is now made to the accompanying drawings, wherein: Figure 1 is a diagrammatic view of an elevator (or cage) with catch gear; Figure 2 is an enlarged sectional view of the catch gear; Figure 3 is a sectional view of the catch gear taken in a plane perpendicular to that of Figure 2; Figure 4 is an end view of a part of the catch gear; Figure 5 is a plan view of the catch gear; Figure 6 is an elevation of a modification of a part of the catch gear; and Figure 7 is an elevation of a further modification of said part of the catch gear.

Referring to figure 1, catch gear is diagrammatically shown to comprise tracks 12, 1 2a and pinions 13, 1 3a. The tracks 12, 1 2a are mounted on support members 14, 1 4a, which are suspended vertically from a framework 1 9. Each track is in the form of a chain having horizontal pivot members 1 5. The pinions 13, 1 3a are rotatably mounted on the underside of an elevator or cage 1 6. The pinions may, of course, be provided in other positions, such as on top of the cage.

The support members 14, 1 4a diverge to define a flared mouth 17, the tracks 12, 1 2a similarly diverging. The cage 1 6 is shown in three positions in figure 1. In the lowest of these positions, as shown in dotted lines, the axes of the pinions, 13, 1 3a lie in a horizontal plane 'A'. In this position the cage is still being raised by a winding mechanism and the pinions have just engaged the tracks, the flared mouth 1 7 facilitating such engagement. In the next position upwardly, the pinion axes lie in horizontal plane 'B' and the cage has become detached from the winding mechanism. The cage continues to move upwardly against gravity until it reaches a momentary rest position, in which the pinion axes are in horizontal plane 'C'. During upward movement of the cage to the rest position, the pinions have been caused to rotate.Means is provided, however, to prevent reverse rotation of the pinions, so that the cage is held in the rest position.

The cage may be in a mine shaft and moved upwardly by a winding mechanism. Means, such as a shear pin, may be provided to detach the cage from the winding mechanism when the cage passes a given point, so that the cage can be caught by the catch gear.

When it is desired to relower the cage, it is possible to move the supports 14, 1 4a angularly apart about a pivot 18 as shown at 'D' to disengage the pinions from the tracks.

Alternatively, the means preventing reverse rotation (described further hereafter) may be released.

When the pinions first engage the tracks, an impact force is received by the supports 14, 1 4a.

This impact force is absorbed by resilient pads 20.

Similarly, the resilient pads absorb the downward impact load caused by sudden application of the cage weight. The first few links of the chain may be resiliently mounted to allow any necessary lateral movement.

Referring now to figure 2, it can be seen that each chain comprises links 29 articulated by the pivot members 15, each pivot member rotatably mounting a roller 31 with which the pinion teeth engage. The angle of the track 12 and the shaping of the teeth 21 of the pinion 13 are such as to ensure engagement of the teeth with the rollers 31. The tooth form shown is preferred at present, but other forms are possible. Guides 22 engage the cage to align the pinions with the tracks. It can also be seen that there is virtually no fall of the pinions relative to the track whatwever the state of engagement of the teeth with the track.

Refering to figure 3, an arrangement is shown in which the pinion 13 has two axially spaced sets of teeth 21a, 21b each engageable with a respective chain 24a, 24b, each track comprising a pair of side by side chains. It can be seen that the guides 22 define flared entries to ensure engagement of the teeth of the pinion with the chains. The chains are secured to the support 14 by cleats 26. Engagement of each pinion with the chain may be ensured by pre-positioning of the pinions angularly by means of shear pins.

The pinions 13 is mounted by a shaft 33 between two lugs 34. 35, dependent from a mounting plate 36 (figures 2 and 3). The mounting plate is secured to the bottom of a cage. The shaft engages in bushes 34a, 35a and projects beyond the bushes to engage at each end with a respective one-way rotary coupling, or clutch 38, 39. These clutches are also dependent from the plate 36, by securance of their housings 38a, 39a thereto. Resilient means may be provided between the mounting plate 36 and the cage.

The clutches permit free running of the pinion 1 3 as the latter runs up the chains 21 a, 21 b, but prevents reverse rotation of the pinion. Each clutch may be of any suitable type and especially may be of a type which comprises a bearing race in which the bearing elements are of wedge shape. Such elements are shaped to act in the same manner as balls when the shaft is rotated one way, but to act as wedges to prevent reverse rotation. Such clutches are well known.

A bolt may be provided, accessible from within the cage, for releasing the clutch housings 38a, 39a to permit reverse rotation of the pinions, so that the cage can be lowered.

The part of the catch gear, which is mounted on the cage may be modified as shown in figure 6 or figure 7. In figure 6, two separate pinions 50, 51 are provided instead of the angle pinion 1 3.

These pinions are spaced with a single one-way clutch 52 mounted between them.

In figure 7, the pinion is constructed and mounted as in figures 2 to 5, but only one oneway clutch 38 is provided on the shaft 33.

Catch gear of the type described above may be provided at several spaced locations at a single station to catch the cage simultaneously. With the arrangement described perfect setting up of the tracks relative to each other is unnecessary and, in view of the very small degree of play between the pinions and the tracks, the cage can settle evenly without excessive weight being supported by one pinion.

The pinions may, of course, be mounted at a stationary location, such as the head gear of a mine and the chains mounted on the cage.

Claims

1. Elevator catch gear for catching an upwardly moving body at a given location, the catch gear comprising a member rotatable in one angular direction and a track positively engageable by the member, during reiative movement between the member and the track in one direction, the member and the track being provided one on the body and the other at said given location, and means substantially preventing rotation of the member in the opposite angular direction whereby the member is held by the track.

2. Elevator catch gear according to claim 1, wherein the track comprises a chain and the member is a pinion.

3. An elevator installation comprising side walls and an elevator raisable and lowerable between the side walls, the installation including a catching station, and catch gear comprising a plurality of catching devices each having a rotatable member and a track mounted one on the side walls at the catching station and the other on the elevator, each member rotatably and positively engaging the corresponding track as the elevator passes upwardly through the catching station, and means substantially preventing opposite rotation of each member, so that the catch gear prevents substantial downward motion of the elevator.

4. An elevator installation according to claim 3, wherein each track comprises a chain and is mounted on the side walls and each member comprises a pinion and is rotatably mounted on the elevator

5. An elevator installation according to claim 4, wherein each chain comprises a multiplicity of equally spaced rollers rotatably mounted on respective pivot pins which pivot pins provide articulation between links of the chain, the pinions having teeth which engage with the rollers of the respective chains.

6. An elevator installation according to claim 4 or 5, including guides for guiding each pinion engagement with the respective chain, each guide having a flared entry.

7. An elevator installation according to claim 4, 5 or 6 including resilient means in the mounting for the chains for absorbing impact forces when the pinions engage the chains.

8. An elevator installation according to any one of claims 2 to 7 wherein the means substantially preventing said opposite rotation of each pinion comprises a one-way rotary coupling.

9. An elevator installation constructed substantially as herein described with reference to the accompanying drawings.

10. A mine shaft installation including an elevator cage raisable in the shaft, a winding mechanism attached to the cage, means to detach the cage from the winding mechanism on over-run of the cage in the upward direction, catch gear to catch the released cage, the catch gear being constructed according to claims 1 or 2.