Patent Grant
11577936
This application claims priority to European Patent Application No. 19306292.4, filed Oct. 4, 2019, and all the benefits accruing therefrom under 35 U.S.C. ยง 119, the contents of which in its entirety are herein incorporated by reference.
The present disclosure relates to elevator aprons (also referred to as toe guards) which protect against passengers falling into the hoistway during passenger rescue operations, in particular this disclosure relates to aprons for use in elevator systems with reduced depth pits (or low profile pits).
The apron or toe guard is provided below the entrance (or entrances) of an elevator car and hangs down from the elevator car adjacent to the hoistway wall. When there is a problem with the elevator system and passengers need to be evacuated from an elevator car, a rescue operation may be performed. During such a rescue operation the elevator car may not be fully aligned with the landing entrance but it may still be possible for passengers to exit the elevator car if the elevator doors are at least partially aligned with a landing. If the elevator car has stopped slightly below a landing position then passengers may be able to step up from the elevator car onto the landing above if the landing doors for that landing are opened. If the elevator car has stopped slightly above a landing position then passengers may be able to drop down from the elevator car onto the landing below if the landing doors for that landing are opened. However, in this latter case (dropping down to a lower floor) when the elevator car is not properly aligned with the landing floor, i.e. when the elevator is offset in the hoistway compared with a normal landing position, there is a gap below the elevator car which, when the landing doors are open, provides access into the hoistway. This gap presents a risk to passengers dropping down from the elevator car because if the gap is large enough then a passenger could fall into the hoistway. For this reason elevator cars are often provided with an apron or toe guard that extends for a distance below the elevator car, in close proximity to the hoistway wall where the landing doors are located, thereby closing (or at least partially closing) the gap and reducing or eliminating the risk to passengers when exiting the car in a rescue operation. In many countries an apron or toe guard is required by regulations (e.g. Code EN 8120 requires an apron of length at least 750 mm).
During normal operation the apron is out of sight, simply hanging below the elevator car. When the elevator car is at the lowest floor, the apron hangs into the pit at the bottom of the hoistway. This is not a problem for larger elevator systems with a full size pit. However, in smaller installations the pit can be reduced in height significantly, in some cases down to around 300 mm, i.e. there is only 300 mm of space below the bottom of the elevator car when the elevator car is at the lowest floor. A 750 mm apron cannot fit into this space. Solutions to this problem have included foldable or collapsible aprons that can move or fold out of the way at the lowest floor, but which will deploy to the full 750 mm required length as the elevator car leaves the lowest floor. However such mechanisms add complexity and cost.
According to a first aspect of the present disclosure there is provided an elevator car comprising: a door; and an apron movable between a deployed position and a retracted position; wherein in the deployed position the apron hangs below the door; wherein in the retracted position the apron is vertically overlapped with the door; and wherein in the retracted position the apron is engaged with the door such that it is movable sideways together with the door.
Allowing the apron to overlap vertically with the door (i.e. such that the door and the apron share an amount of vertical extent or such that a certain height range is occupied by both the apron and the door) means that the apron can be simply displaced upwards when the elevator car reaches the lowest landing and the apron contacts the pit floor. No complex folding mechanism is required to fit the apron within the pit area. As the apron is displaced upwards relative to the elevator car it will block the doorway which would prevent passengers from entering or exiting the car during normal operation (i.e. when entering or exiting at the lowest floor). However, as the apron according to this disclosure is engaged with the door in the retracted (i.e. non-deployed) position, opening the door also moves the apron out of the way of the doorway so that the apron does not hinder passengers from using the elevator car. This arrangement is especially useful in elevators with shallow pits as a full length apron can be used without needing to fold it or rotate it out of the way in order to allow access to the lowest floor.
The apron has sufficient rigidity that it holds its form while it is supported by the pit floor and while the elevator car descends to the lowest floor. The rigidity of the apron may come from the thickness of the material, but can also be affected by adding additional structures to increase rigidity. For example, additional stiffening structures could be added to the apron to increase rigidity. In some examples telescoping stiffeners could be added which provide extra support to the panel by extending as the apron moves to the retracted position. In other examples, the apron could be shaped for increased rigidity, e.g. by adding one or more bends or folds to the apron. In some examples the apron may have a bend at one or both sides, e.g. a right-angle bend. To minimise the space that the apron occupies between the elevator car and the hoistway wall, the bend(s) may be accommodated within the elevator car door sill. In such examples the elevator car door sill may have a vertical slit to accommodate the bend of the apron as it moves vertically between the deployed position and the retracted position. Additionally the apron may have a slit formed in the bend to allow movement past the elevator car door sill during door opening and closing when the elevator car is at the lowest floor (and the apron is in the retracted position). The position of the slit in the bend of the apron will be determined by the depth of the pit so that it aligns with the sill.
When the elevator car is not at the lowest floor (and when it leaves the lowest floor) the weight of the apron causes it to move to the deployed position where it provides its normal function, hanging below the elevator car and obstructing access to the hoistway in the event of a rescue operation in which passengers need to be helped down to a lower landing. The apron may move from the retracted position to the deployed position under gravity alone, i.e. based solely on the weight of the apron. Additional weight (e.g. filler material) may be added to the apron if desired to ensure reliable deployment.
When the apron is in the retracted position it is moved sideways when the elevator car door is opened and therefore does not perform its function of obstructing access to the hoistway. However, as this only ever happens when the elevator car is at the lowest floor and when the apron is in contact with the pit floor, the access to the hoistway is not a severe risk.
It should be noted that this only applies at the lowest landing, adjacent the pit. At all other landings there is plenty of room below the elevator car for the apron to hang in its deployed position under the elevator car door. Thus in the deployed position the apron may be disengaged from the elevator car door such that it will not move sideways together with the elevator car door. Therefore in the event of a rescue operation being required, the elevator car door can be opened without moving the apron so that the apron performs its function of obstructing the opening onto the hoistway and reducing the risk to passengers and/or rescuers.
The elevator car door can take many different forms. For example a single sliding door panel that opens to one side is viable. So long as there is room for the door to slide out of the way there will also be room for the apron to be moved out of the way. However, in most elevators the space for door opening is constrained and therefore elevator car doors tend to have at least two panels. The two most common types of elevator doors are centre-opening doors and telescoping doors. In centre-opening doors one panel slides open to one side while the other panel slides open to the opposite side. In telescoping doors both panels (or indeed three or more panels) slide to the same side of the doorway but are offset so that they can slide past each other (i.e. so that the panels substantially fully overlap with each other when the door is fully open). Of course a centre-opening door is possible in which both sides feature a telescoping arrangement.
Therefore in some examples the elevator car door comprises a first door panel and a second door panel and the apron comprises a first apron panel and a second apron panel; wherein in the retracted position the first apron panel is vertically overlapped with the first door panel and the second apron panel is vertically overlapped with the second door panel.
In such arrangements the apron is split into two (or more) separate panels, each arranged to move with a different door panel. In this way the apron panels can be moved into the same horizontal spaces as the door panels, thereby ensuring that there is always sufficient horizontal space to accommodate the apron in the retracted, door-open position. In this regard it may be noted that in cases where there is a wide hoistway and/or a wide pit, the apron could be kept as a single panel and arranged to move with one of the door panels. A slightly more complex engagement mechanism may be required in such examples to ensure that the apron moves fully out of the doorway, but such examples are still viable.
In some examples the first apron panel is arranged such that when it is in the retracted position it moves sideways together with the first door panel, and the second apron panel is arranged such that when it is in the retracted position it moves sideways together with the second door panel.
As discussed above, the elevator car door may be a centre-opening door in which the first door panel is movable to one side of the elevator car and the second door panel is movable to the other side of the elevator car during door opening.
Also as discussed above, the elevator car door may be a telescoping door in which the first door panel and the second door panel are movable to the same side of the elevator car during door opening.
The apron can be arranged to overlap with the elevator car door in different configurations. For example the apron could be arranged to overlap on the outside of the elevator car door (i.e. between the elevator car door and the landing door). It will generally not be preferred to have the apron overlap with the elevator car door on the inside of the door as this could cause a hazard to passengers, although in cases where an additional protection was in place this could also be viable. However, in some examples in the retracted position the apron is disposed at least partly inside the elevator car door. Thus the apron overlaps with the door by extending upwards inside the door, i.e. inside a cavity of the door. This is a particularly space efficient arrangement which does not require any additional space to be designed in between the elevator car doors and the landing doors. It also prevents the apron from catching on anything on the outside of the elevator car door when it is moved into the retracted position. Also, as the apron is often conveniently arranged to hang from the door sill when it is in the deployed position and as the door sill is located directly under the door, this arrangement is particularly convenient.
In some examples in the deployed position the apron hooks onto a door sill underneath the door. The apron may therefore in some examples have one or more hooks or lips formed at the top edge thereof which can rest or hook onto the sill. The apron is thus held in the deployed position in which it hangs below the elevator car door, but can be lifted clear of the sill in order to move to the retracted position (e.g. through contact with the pit floor while the elevator car continues to descend).
In some examples the elevator car door comprises a first engagement part and the apron comprises a second engagement part arranged to engage with the first engagement part when the apron is in the retracted position such that movement of the elevator car door in either horizontal direction causes corresponding movement of the apron. The first and second engagement parts could take a number of different forms. For example one engagement part could be a roller while the other engagement part is a slot (preferably a vertical slot) such that the roller is arranged to roll into and out of the slot. With the roller located within the slot, movement of either the roller or the slot could cause movement of the other in either direction (a relatively tight fit is preferred with little or no play so as to ensure the two parts move in unison). In other examples two rollers could be arranged to engage either side of a flange. With each roller arranged to engage the flange and remain in contact therewith, the two parts would move in unison. In yet further examples a flange could engage within a slot. It will be appreciated that these examples are given by way of example only and are not intended to be limiting. In each case, it is not important which engagement part is attached to the door and which is attached to the apron. Both possibilities are equally functional.
In some examples one of the first engagement part and the second engagement part comprises a pin and the other of the first engagement part and the second engagement part comprises a horizontal groove interconnected with a vertical groove; wherein the pin is slidably mounted in the grooves such that when the apron is in the deployed position the pin slides within the horizontal groove and such that when the apron moves between the deployed position and the retracted position the pin slides within the vertical groove. The horizontal groove essentially decouples the apron and the door, allowing relative movement of the door and the apron (specifically allowing movement of the door while leaving the apron in place in its deployed position), thereby allowing normal operation of the elevator doors without movement of the apron and ensuring that the apron stays in the deployed, protective position if the elevator doors are opened during a rescue operation at any floor other than the lowest floor. The vertical groove allows the relative movement of the apron and the door when the elevator car approaches the lowest floor and the apron contacts the pit floor. As the elevator car continues to move downwards after the apron has contacted the pit floor, the pin slides within the vertical groove and the apron and door begin to vertically overlap. The vertical groove also provides the engagement means by which to move the apron together with the elevator car door. While the pin is located within the vertical groove, horizontal movement of one part will cause corresponding movement of the other part. Thus as the door opens at the lowest floor, the apron is moved with the door so as to allow passengers to enter and exit the car. Equally, as the door closes, the apron is moved back in front of the doorway so that when the elevator car leaves the lowest floor the apron is deposited back in its deployed and protective position.
The horizontal groove and the vertical groove could be formed in the apron with the pin being formed in or attached to the door. Equally the pin could be formed on or attached to the apron while the groove is formed in the elevator door.
The grooves (both horizontal and vertical) may be formed as troughs or depressions in the surface of the relevant component (i.e. not through-holes), or they may be formed as cuts or apertures (i.e. through-holes).
The pins and grooves should ideally be sized so as to accommodate a small amount of misalignment during use. Such misalignments are not expected to be very large as the weight of the apron will determine alignment with the horizontal groove in a very repeatable manner and door positioning is generally controlled accurately such that alignment with the vertical grooves is likely to be quite accurate. Nevertheless, to accommodate some misalignments the horizontal and vertical grooves may be interconnected via rounded corners or chamfered connections (i.e. such that the grooves are wider at the intersection, tapering to a narrower width away from the intersection) so that any misalignment is accommodated at the intersection and the pins are guided by the rounded corner or chamfer into the appropriate groove during the early stages of relative movement.
In some examples, one engagement part is provided on the apron and the other engagement part is provided on a guiding plate attached to the elevator door. The guiding plate may extend below the bottom of the elevator door. This is advantageous as the apron may, in its deployed position, be located fully below the elevator door (i.e. with no vertical overlap therewith). The guiding plate can provide that overlap so that the engagement parts can be engaged even before any overlap has occurred. Another advantage is that the overlap between the apron and the guiding plate can ensure the verticality of the apron during its retraction and during door opening at the lowest floor.
In some examples the horizontal groove and the vertical groove are formed in the guiding plate attached to the elevator car door.
The guiding plate may be attached to the front of the elevator car door, i.e. to the side of the door that faces the landing, where it will not be visible to passengers. In other examples the guiding plate may be attached inside the elevator car door.
In some examples rollers are provided between the bottom of the apron and the pit floor. Such rollers can reduce the friction and also the noise that would otherwise occur as the apron (which would otherwise be in direct contact with the pit floor) is dragged across the floor. The rollers greatly reduce the friction and noise and put less strain on the door motor. The rollers may be attached to the bottom of the apron so that they travel with the apron and do not obstruct work in the pit. Alternatively the rollers may be provided on the pit floor so that they do not need to be carried by the elevator car.
The elevator car may further comprise a rigid support structure extending downwardly from the bottom of the elevator car adjacent to the apron to provide support and rigidity to the apron in the deployed position, the rigid support structure extending downwardly from the elevator car by a distance less than 300 mm (or less than the depth of the pit). The rigid support structure provides support to stop the apron from swinging or hanging out of its protective position when it is in the deployed position. The majority of the rigidity is provided by the apron and therefore the support structure can be kept to a short length, specifically shorter than the pit depth even in the case of shallow pits. A support of less than 300 mm is smaller than the shallowest pits currently in use, but provides ample support to the apron.
As mentioned above, certain regulations require a certain length of apron, e.g. 750 mm. The length of vertical overlap between the apron and the elevator car door will depend on the depth of the pit and the size of the apron. To give an example, if the apron has a length of 750 mm and the pit has a depth of 300 mm then the elevator car door and the apron may overlap by around 400 mm or more (allowing a small distance between the bottom of the car and the bottom of the door). In less shallow pits (but still shallower than a full depth pit), the overlap may be at least 200 mm or at least 300 mm. Of course the apron length set by the regulations is a minimum requirement. A longer apron can block a larger portion of the hoistway during a rescue operation and therefore a longer apron (with a length greater than 750 mm, e.g. at least 1 m) may be desirable for improved safety. Therefore the overlap could be significantly more in such cases. The arrangement according to this disclosure generally permits an apron of greater length than the pit depth and therefore facilitates the use of longer aprons.
The apron may be provided with a chamfer at its lower edge (i.e. an angled part that is angled away from the landing, into the hoistway) as a further protective measure. In the event of unexpected movement of the elevator car during a rescue operation this chamfer may prevent a foot from becoming trapped and/or sheared between the elevator car and the landing.
According to another aspect of the present disclosure there is provided a method of operating an elevator car, wherein the elevator car comprises a door and an apron, the method comprising: as the elevator car approaches its lowest landing, the apron moving from a deployed position in which it hangs below the door to a retracted position in which it is vertically overlapped with the door and engaged with the door; and opening the door, and thereby moving the apron sideways together with the door.
It will be appreciated that all of the optional features described above in relation to the first aspect may also optionally be applied to the second aspect.
Certain examples of the present disclosure will now be described, by way of example only, with reference to the accompanying drawings in which:
The elevator car 1 is shown in
The cross-section of
The arrangement shown in
The arrangement shown in
In this retracted position, the apron 7 overlaps vertically with the door 5 and therefore also overlaps the doorway that will be used by passengers to enter or exit the elevator car 1. However, in this retracted position, the apron panels 7a, 7b are each engaged with the respective guiding panels 6a, 6b which are in turn mounted on the respective door panels 5a, 5b. As shown in
Another important aspect of this example is that the apron 7 should not be moved if the elevator car door 5 is opened at any floor other than the lowest floor.
As can be seen in
It will be appreciated that many variations of this example are possible within the scope of the claims. For example the pins 12 could be provided on the guiding panel 6 with the grooves 13, 14 formed in the apron 7. Such an arrangement is generally less preferred as the strength and rigidity of the apron 7 is important and so it is preferred not to form grooves in it. Alternatively the pins or the grooves could be formed directly on the door panels 5a, 5b without any intervening guiding panel 6. Further, while pins and grooves (or slots) are one way to achieve the engagement between the apron 7 and the door 5, other engagement mechanisms are also possible such as rollers engaging with flanges. In such examples, the vertical extent of the flanges can be chosen so that they engage with rollers on the other part when the parts overlap (in the retracted position when it is desired to move them together), but when the apron is in the deployed position the rollers lie above or below the flanges so as not to engage therewith. It will also be appreciated that a similar arrangement may be used on telescoping doors where two door panels 5a, 5b retract towards the same side of the doorway. In such examples both apron panels 7a, 7b would also be retracted to the same side of the doorway. There may be a small depth offset between the two apron panels 7a, 7b in such arrangements (i.e. one is located slightly further into the hoistway from the landing), but not enough to create a risk to passengers. The functionality described above would otherwise apply equally.
| Number | Date | Country | Kind |
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| 19306292 | Oct 2019 | EP | regional |
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| European Search Report for Application No. 19306292.4; dated Apr. 17, 2020; 5 Pages. |
| Number | Date | Country | |
|---|---|---|---|
| 20210101785 A1 | Apr 2021 | US |
