The present invention relates to a device and procedure for creating and securing a temporary safety space within an elevator hoistway such that a service or maintenance engineer can work with impunity from a car entering the safety space. In particular, the invention provides a stop bar for mounting within the hoistway to prevent movement of the car into the safety space.
In recent years pressure within the elevator industry to reduce the space consumption of installations has increased dramatically. This has resulted in the design of modern elevator systems in which:
Hence, there is a requirement to provide a temporary safety space within the hoistway of modern systems before maintenance or service work can be carried out. Furthermore, when the machine is mounted in the hoistway, the frequency at which the hoistway must be accessed for maintenance or service work is increased. Accordingly, it is important that the means for creating the temporary safety space can be established and reset quickly and reliably.
Many prior art solutions have been proposed to create the necessary temporary safety spaces. For example, EP-A-0985628, illustrates height adjustable railing members disposed on the top of the roof of an elevator car. During normal elevator operation, the railing members are maintained in a position lower than the highest protrusion from the car roof so that they do not interfere with the travel of the elevator. When maintenance is to be carried out, the railing members are raised to an upright position, thereby establishing a temporary safety space defined between the top of the car and the top of the railing members.
A similar solution is described in WO-A-02085773 wherein a folding framework is mounted on top of the roof of the elevator car. When maintenance is to be carried out, the framework is unfolded and extends vertically above the car to establish a safety space.
A common problem associated with these two solutions is that they are only capable of establishing a safety space in the headroom of the hoistway above the car. Furthermore, the railing members of framework extend vertically through the safety spaces and they create and this may impede the maintenance engineer in carrying out the required work.
A common approach is establishing the required safety space in the pit of the hoistway is described in EP-A-0725033. A buffer is pivotably mounted to the floor of the pit. In normal elevator operating conditions the buffer is retained in a vertical position where it has no influence on the travel of the elevator car. When work is to be carried out in the pit, the buffer is released from its retained position and tilts under gravity into a safety position where it prevents travel of the car into the pit. Similar supports are described in DE-A-10065099. Again, however, these safety devices when creating a safety space in the pit actually extend through the safety space and this may impede the maintenance engineer in carrying out the required work.
U.S. Pat. No. 5,773,771 describes an apparatus for restricting the motion of an elevator car. The apparatus consists of two bolts extensible from either side of a bottom bolster channel supporting the car. In the extended position, the bolts engage with steel plates mounted to the guide rails thereby preventing upward motion of the car. If a service technician is working on the top of the car, it would be difficult, if not impossible, for him to see whether the bolts have extended and correctly engaged with the steel plates. Hence, he cannot be entirely confident that the car has been prevented from moving.
Accordingly there is a need to overcome the aforementioned problems associated with the prior art by providing a simple, effective, reliable and visible means and method of creating both pit and headroom safety spaces which does not intrude into the safety space so established to hamper maintenance work.
Pursuant to the present invention, an assembly is presented for providing a temporary safety space within an elevator hoistway wherein upward or downward movement of a car or a counterweight along guide rails is prevented. The assembly includes engagement members provided on the guide rails and a stop bar having opposing ends that bear against the engagement members. The engagement members can be arranged to permanently secure the guide rail to the hoistway, can be a hole provided in the guide rail, or temporarily fixed to the guide rail to create the temporary safety space.
Another aspect of the invention resides in a method for creating such a temporary space within an elevator hoistway. The method includes switching a control system to an inspection mode, providing engagement means on the guide rails and installing a stop bar having opposing ends which bear against the engagement means. The engagement means can be bolts used to permanently secure the guide rail to the hoistway, holes in the guide rail, or bolts temporarily fixed to the guide rail.
By way of example only, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, of which:
When maintenance/inspection work is to be carried out in the hoistway 10 the technician stops the car 2 at a predetermined level in the vicinity of a specific landing door of the hoistway 10, opens that landing door and climbs onto the roof 4 of the car 2. From there the technician switches the control system of the elevator 1 to inspection mode thereby enabling the car 2 to travel at a reduced speed upwards or downwards within the hoistway 10 under the supervision of the technician.
In order to create a temporary safety space above the car 2, the stop bar 20 is arranged as shown in
To reduce the initial and any subsequent impact forces between the stop bar 20 and the car 2 a layer of resilient material 22 such as rubber is provided on the lower surface of the stop bar 20.
In order to create a temporary safety space in a pit of the hoistway 10 below the car 2, the stop bar 20 is arranged as shown in
Although the guide shoes 6 of this particular embodiment are positioned at the top of the car 2, it will be appreciated that the shoes 6 can be mounted at any position along the height of the car 2.
Over time the opposing guide rails 12 of an elevator system 1 can become misaligned. Accordingly, the distance between them can vary along the length of the hoistway 10. The stop bar 20 of the previously described embodiment, being of a single-piece construction, cannot account or adjust for these changes. Accordingly, an alternative, telescopic stop bar 40 as shown in
Obviously the embodiments of
Instead of using the bolts 18 and the nuts 19 on the guide rails 12, temporary fastening means such a clamp or bolt could be used to secure the ends of the stop against the guide rails 12 as illustrated in
Again when maintenance inspection work is to be carried out in the hoistway 10 the technician stops the car 2 at a predetermined level in the vicinity of a specific landing door of the hoistway 10, opens that landing door and climbs onto the roof 4 of the car 2. Instead of manually switching the control system of the elevator 1 to inspection mode, the technician merely removes the stop bar 60 from its stored position (
A further arrangement is shown in
Since the maintenance technician must generally climb onto the roof 4 of the car 2 to switch (whether manually or through installation of the stop bar 60) the control system of the elevator 1 to inspection mode, the roof 4 is the most logical place to store and install the stop bar 20, 40, 50, or 60. However, it will be appreciated that the stop bar 20, 40, 50 or 60 could alternatively be installed on the bottom of the car or indeed on a counterweight of the elevator system, 1 having its own guide rails.
Although the present invention has been described in relation to particular embodiments thereof, many other variations and modification s and other uses will become apparent to those skilled in the art. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the appended claims.
Number | Date | Country | Kind |
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03 405 215.9 | Mar 2003 | EP | regional |
The present application is a continuation-in-part of co-pending patent application Ser. No. 10/804,243, filed Mar. 13, 2004, the entire contents of which are incorporated herein by reference.
Number | Date | Country | |
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Parent | 10804243 | Mar 2004 | US |
Child | 11981978 | Oct 2007 | US |