This application claims priority to European Patent Application No. 19315104.0, filed Aug. 27, 2019, and all the benefits accruing therefrom under 35 U.S.C. § 119, the contents of which in its entirety are herein incorporated by reference.
This disclosure relates to an elevator car with a working platform used to carry out maintenance from inside an elevator car, and in particular to measures to ensure a sufficient safety space for workers on the working platform.
It is known to create a safety space above an elevator car by placing props within the pit of an elevator hoistway, below a counterweight travel path, such that movement of the counterweight below a certain height is prevented, and thus movement of an elevator car, to which the counterweight is connected, above a certain height is prevented. This provides a certain safety space in the overhead of the elevator hoistway. However, it is generally desirable to reduce the overhead in elevator systems so that building space is optimised.
It is also known to provide working platforms located in or above the ceiling of elevator cars, which are moveable between a stowed position and a deployed position. In the deployed position, the working platform is located within the car, at such a height that a maintenance person is able to stand on the working platform and access elevator components inside the hoistway through an opening in the elevator car ceiling. The safety of workers on such a working platform must be ensured at all times.
According to a first aspect of this disclosure, there is provided an elevator car comprising: a working platform moveable between a stowed position, at an upper part of the elevator car, and an operational position, suspended from the upper part of the elevator car to be inside the elevator car; at least one stop located at the upper part of the elevator car, wherein the at least one stop is moveable between a retracted position and a deployed position, and wherein, in the deployed position, the at least one stop extends away from the upper part of the elevator car to provide an upper safety space above the elevator car.
According to a second aspect of this disclosure, there is provided a method of
of creating a safety space above an elevator car, the elevator car comprising: a working platform moveable between a stowed position, at an upper part of the elevator car, and an operational position, suspended from the upper part of the elevator car to be inside the elevator car; the method comprising: attaching at least one stop at the upper part of the elevator car, such that the stop is moveable between a retracted position and a deployed position; wherein, in the deployed position, the at least one stop extends away from the upper part of the elevator car to provide an upper safety space above the elevator car.
According to a third aspect of this disclosure, there is provided a method of employing a safety space above an elevator car, the elevator car comprising a working platform moveable between a stowed position, at an upper part of the elevator car, and an operational position, suspended from the upper part of the elevator car to be inside the elevator car; and at least one stop located at the upper part of the elevator car; the method comprising: moving the working platform to the operational position inside the elevator car; standing on the working platform, so as to protrude through the upper part of the elevator car; and manually operating the at least one stop to move the at least one stop from a retracted position to a deployed position, in which the at least one stop extends away from the upper part of the elevator car to provide an upper safety space above the elevator car.
In at least some examples, such a method may further comprise: locking the at least one stop in the deployed position using a locking mechanism.
It will be appreciated that the at least one stop can be deployed to create a safety space above the car when a maintenance person is stood on the working platform.
In at least some examples, in addition or alternatively, the at least one stop lies transversely across the upper part of the elevator car in the retracted position. In at least some examples, the at least one stop lies diagonally across the upper part of the elevator car in the retracted position. A choice may be made about whether to accommodate the at least one stop transversely or diagonally depending e.g. on the length of the stop(s). In some examples, a longer stop may help to meet safety code requirements for the upper safety space above the elevator car. A stop can be made longer in a diagonal arrangement as compared to a transverse arrangement. This may avoid the at least one stop extending horizontally beyond the footprint of the elevator car, and/or reduce the height above of the elevator car of any attachment for the at least one stop, thereby saving spacing in one or more dimensions of the hoistway.
In at least some examples, in addition or alternatively, the at least one stop comprises a first stop and a second stop located at opposed sides of the upper part of the elevator car. By providing a pair of stops, forces on the elevator car are more balanced in the event that the stops engage against a ceiling of the hoistway when deployed. Furthermore, providing a second stop ensures redundancy in the event that the first stop fails to deploy or due to buckling of one stop.
In a first set of examples, the first and second stops lie transversely across the upper part of the elevator car in the retracted position, and extend away from the upper part of the elevator car substantially offset from one another in the deployed position. In such examples, optionally the first stop is located towards the front of the upper part of the elevator car and the second stop is located towards the rear of the upper part of the elevator car. Since the first and second stops are offset from one another, this helps to ensure that the stops do not interfere with one another, particularly when in the retracted position. Both the first and second stops can lie across the upper part of the elevator car in the same plane, minimising the overhead space required.
In a second set of examples, the first and second stops lie diagonally across the upper part of the elevator car in the retracted position, and extend away from the upper part of the elevator car substantially opposite one another in the deployed position. Again, both the first and second stops can lie across the upper part of the elevator car in the same plane, minimising the overhead space required. Furthermore, when the first and second stops extend opposite to each other, there is neither a risk of creating a torque when hitting the top of the hoistway nor is there a risk of creating an imbalance in weight of the elevator car.
As mentioned above, the stops can potentially be made longer when they lie diagonally. In the case of a stop which lies transversely in the retracted position, if a stop is required which is longer than the width of the car (i.e. if placed transversely it would extend horizontally beyond the footprint of the car) then either the stop must be extended further beyond the car footprint, which would then require a wider hoistway, or, as described below, a mounting bracket could be made to extend higher above the car, thus requiring a taller hoistway. A diagonal arrangement allows for the stop(s) to be made longer, without necessarily requiring further space (either as additional width or height) in the hoistway to accommodate the longer stop. This may be exploited even in examples having a single stop.
In at least some examples, in addition or alternatively, the at least one stop is hinged to move between the retracted position and the deployed position. For example, the at least one stop may be hinged around a point which is above the upper part of the elevator car.
In at least some examples, in addition or alternatively, in the retracted position, the at least one stop extends horizontally beyond the footprint of the elevator car. As mentioned above, this may depend on the length of the at least one stop and whether the at least one stop lies transversely or diagonally across the upper part of the elevator car in the retracted position.
In at least some examples, in addition or alternatively, the elevator car further comprises at least one upright, wherein the at least one stop is attached to the at least one upright. In such examples, the elevator car may further comprise a mounting bracket arranged to connect the stop to the upright. In some examples, the mounting bracket may provide a hinged connection between the at least one stop and the upright. In some examples, the mounting bracket may provide a mating connection between the at least one stop and the upright. For example, a mating connection may allow the at least one stop to be received in a correspondingly shaped recess in the upright.
In at least some examples, in addition or alternatively, the at least one stop is configured to be manually operated to move between the retracted position and the deployed position.
In at least some examples, in addition or alternatively, the elevator car further comprises a locking mechanism arranged to lock the at least one stop in the deployed position. In some examples, the locking mechanism comprises a locking pin. For example, the locking pin may be configured such that, when the at least one stop is in the deployed position, the locking pin is moveable to a locking position. The locking pin may be manually or automatically moveable to the locking position. In some examples, the locking mechanism comprises a spring arranged to bias the locking pin into the locking position. In the locking position, the pin may intersect the at least one stop to hold the at least one stop in the deployed position.
In at least some examples, in addition or alternatively, the at least one stop further comprises a buffer portion, at the distal end of the stop. The buffer portion may be formed of any suitable resilient, e.g. elastomeric material, such as rubber.
In at least some examples, in addition or alternatively, the elevator car further comprises a roof frame located at the upper part of the elevator car, wherein the working platform sits within the roof frame in the stowed position to define the roof of the elevator car. Optionally, the working platform is suspended from the roof frame. The roof frame may therefore act as a support frame for the working platform. It will be appreciated that it is standard practice for an elevator car to be completely enclosed by walls, floor and a roof.
In at least some examples, in the deployed position, the at least one stop extends substantially perpendicular to the roof frame. This can help to ensure that the at least one stop is stable in the deployed position.
In at least some examples, in addition or alternatively, in the retracted position, the at least one stop lies substantially parallel to the roof frame. This can ensure that the at least one stop does not take up unnecessary space above the elevator car when not in use.
There is also disclosed herein an elevator system comprising an elevator car according to any of the disclosed examples, and a drive mechanism arranged to drive the elevator car up and down in a hoistway.
Certain preferred examples of this disclosure will now be described, by way of example only, and with reference to the accompanying drawings, in which:
Once the decorative ceiling panel 14 has been hinged, or moved, out of the way, the working platform 4 can be removed from the stowed position and moved downwards into the elevator car 1, as is shown in
In the operational position, a maintenance person may stand on the working platform 4, such that, when stood fully upright, a portion of the top part of the maintenance person's body will protrude through the opening in the roof frame 2, into the hoistway. From this position the maintenance person can access many of the elevator system components which are located within the elevator hoistway, and thus perform essential maintenance.
It is important to ensure that the maintenance person is protected when carrying out maintenance in an elevator system. In order to ensure this, safety regulations such as EN81-20 have been introduced. In particular, it is required that a maintenance person be provided with a certain minimum “safety space” in which to work, which is a protected space within the elevator hoistway which a maintenance person can access to perform maintenance, and into which elevator components are prevented from travelling. There exist systems in the prior art in which a maintenance person stands on the top of the elevator car to carry out maintenance work. In these systems it is known to include stops or props within the hoistway pit, to prevent downwards movement of the counterweight below a certain height, and thus prevent the elevator car from ascending beyond a certain height. In this way a safety space is created above the elevator car in which a maintenance person may safely work.
The safety regulations specify two different safety space allowances. If a refuge, or safety space, has horizontal dimensions of at least 0.5 m×0.7 m, then it is sufficient to provide a maintenance person with a safety space of a height of 1 m, in which they can crouch. In an elevator car 1 of the type described above, including a working platform 4 which is moved down into the elevator car 1, if the horizontal footprint of the elevator car is sufficiently large then the safety space will only need to be 1 m tall. This is generally less than the distance from the working platform 4 in the operational position to the roof frame 2 at the top of the elevator car, and hence the space within the elevator car 1 will be sufficient to provide the necessary safety space.
However, if the elevator car 1 has small horizontal dimensions, smaller than 0.5 m×0.7 m, as is sometimes desirable, then a so-called “type 1”, or upright, safety space is required. In this case, minimum horizontal dimensions of 0.4 m×0.5 m must be provided in the safety space, but also the protected space must now be sufficiently tall to allow a maintenance person to safely stand upright in the safety space and be protected. In this case, the space within the elevator car 1, above the working platform 4, and below the roof frame 2, is usually not sufficient, as a minimum height of 2 m is required for the safety space.
In order to overcome this issue, and create a sufficiently large safety space, at least one stop 6a is provided above the elevator car 1. In some preferred examples illustrated herein, the elevator car 1 comprises a first stop 6a and a second stop 6b. The elevator car 1, and in particular the first stop 6a and the second stop 6b, are shown in more detail, in the retracted position, in
The stop 6a can be attached to the elevator car 1 in any suitable way. The stop 6a could be attached to the elevator car 1 only in its deployed position, described below, for example one or more such stops 6a could be received in a correspondingly shaped recess to form a mating connection which holds each stop 6a upright in the deployed position. Alternatively, the stop 6a could be attached at all times to the elevator car 1. In some examples, the stop 6a may be attached directly to the roof frame 2. Alternatively, as seen in
In these examples, the stop 6a comprises a buffer portion 10a at the distal end of the stop 6a. Similarly, the stop 6b comprises a buffer portion 10b at the distal end of the stop 6b. The buffer portions 10a, 10b may be formed of rubber or any other resilient material. The distal end of each of the stops 6a, 6b will be understood by the skilled person as the end of the stop 6a, 6b which is furthest from the mounting bracket 12a, 12b, which is also the end furthest from the elevator car 1, when the stop 6a, 6b is in the deployed position.
Once a maintenance person has moved the working platform 4 to the operational position, and is stood on the working platform 4, they are then in a position to be able to move the stops 6a, 6b from the retracted position, as shown in
In the example seen in
Once the maintenance person has moved the stops 6a, 6b from their retracted position to their deployed position, the stops 6a, 6b can be fixed in the deployed position using a locking mechanism shown in more detail in
In the deployed position, the stops 6a, 6b are arranged to provide an extension of the structural part of the elevator car 1 i.e. an extension of the uprights 8a, 8b, so that if the elevator car 1 were to move, uncontrolled, upwards in the hoistway then the stops 6a, 6b and in particular the buffer portions 10a, 10b will contact the top of the hoistway and prevent further movement, guaranteeing a maintenance person a total safety space sufficient to meet code requirements.
In the example shown in
In some examples, the elevator car 1 is arranged such that each stop 6a, 6b is hinged to fold down from the deployed position to the retracted position, and to lie substantially horizontally above the roof e.g. roof frame 2. If, as an alternative to the offset stop layout described above, each stop 6a, 6b were to be attached at the same distance from the front of the elevator car 1, on opposed side walls, then the stops 6a, 6b would interfere with each other when folded down into the retracted position. One of the stops would have to lie on top of the other stop, which would thus increase the height of the stops in the retracted position and so have the negative effect of increasing the overhead height required for the elevator car 1. The offset stop layout described above is therefore particularly advantageous since the stops 6a, 6b can be folded into a retracted position as shown in
An alternative to this arrangement is shown in
As already mentioned, the stops 6a, 6b may not be attached to the car uprights 8a, 8b in a hinged manner. The stops 6a, 6b could be placed in the diagonal arrangement shown in
In some examples, the mounting brackets 12a, 12b (or other mounting arrangement) for the stops 6a, 6b are arranged so that the stops 6a, 6b hinge around the top edge of the roof frame 2. In other examples, the stops 6a, 6b are arranged to hinge about a point which is located above the top of the roof e.g. as defined by the roof frame 2. For example, it can be seen in
As laid out above, it is desirable according to safety regulations, that in certain circumstances, a maintenance person is provided with a total safety space 16 of a height of at least 2 metres. This total safety space height of 2 m is indicated in
In order to provide the desired total safety space 16, the total extension above the elevator car 1 provided by the stops 6a, 6b must therefore be at least 0.9 m, i.e. the upper safety space 53 created by the stops 6a, 6b must be at least 0.9 m. However, in some cases the width of the elevator car 1 may be less than 0.9 m, for example the width of the elevator car 1 may be 0.8 m or 0.7 m. In such a case, if the stops 6a, 6b hinged directly around the top of the roof frame 2, the stops 6a, 6b would need to be of a length of 0.9 m, and would therefore extend, in the retracted position, far outside of the footprint of the elevator car 1. In order to avoid this, the mounting brackets 12a, 12b extend above the top of the roof frame 2, and the stops 6a, 6b are hinged about the top of the mounting brackets 12a, 12b, so that this offset contributes to the total height of the stop arrangement in the deployed position. The total extension height 54 of the upper safety space 53 of 0.9 m (as seen in
The diagonal arrangement shown in
In the illustrated examples, the elevator car 1 includes a roof frame 2 and the working platform 4 is suspended from the roof frame 2. However, the roof frame 2 may be omitted and the working platform 4 may be suspended from the upper part 3 of the elevator car 1 in any suitable way. Whether or not the elevator car 1 includes a roof frame 2, the upper safety space 53 (e.g. as seen in
In this example, the locking mechanism 60 includes an internal spring (not visible), which biases the pin 62 into the locking position. As a result of this spring, the pin 62 is constantly pushed towards the locking position, so that, as soon as the through-holes on the mounting bracket 12a and the stop 6a align, the pin 62 is pushed by the spring into the locking position, passing through both of the through-holes. The locking mechanism 60 is thus self-locking and no additional force need be applied by a maintenance person to lock the stop 6a, once it has been moved to the deployed position. This advantageously provides a locking mechanism which is simple to deploy.
The locking mechanism 60 must be unlocked in order to be able to move the stop 6a from the deployed position to the retracted position. The pin 62 is moved out of the locking position by applying a force to the grip portion 68, sufficient to overcome the bias of the internal spring. This force, applied for example by a maintenance person, thus pulls the pin 62 back through the through-hole 66 of the stop 6a, and possibly also through the through-hole of the mounting bracket 12a, while the outer portion 64 stays fixed in position. Once the locking pin 62 is moved to the unlocking position, seen in
Although the stops described herein are particularly advantageous in elevator cars having a small horizontal footprint, it will be understood that they can also be advantageous in systems with a larger horizontal footprint and can provide improved safety also in these systems.
It will be appreciated by those skilled in the art that the disclosure has been illustrated by describing one or more specific examples thereof, but is not limited to these examples; many variations and modifications are possible, within the scope of the accompanying claims.
Number | Date | Country | Kind |
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19315104.0 | Aug 2019 | EP | regional |