GB2395474A

GB2395474A - Lift door safety system

Info

Publication number: GB2395474A
Application number: GB0226941A
Authority: GB
Inventors: Peter Collins
Original assignee: Airdri Ltd
Current assignee: Airdri Ltd
Priority date: 2002-11-19
Filing date: 2002-11-19
Publication date: 2004-05-26
Anticipated expiration: 2022-11-19
Also published as: GB0226941D0; GB2395474B

Abstract

A method of operating a lift door system 15 wherein a plurality of emitters EA provide a series of beams of electromagnetic radiation, such as of infra red, are directed from one side of a gap of variable size to the other side of the gap where the beams can be received by a complementary series of receivers RA, the gap providing for access to a lift car B characterised by the step of identifying by an indicator a point of emission of a beam as aforesaid or of a point of reception of a beam so as to provide a visible identity for the existence of a beam as aforesaid to enable a user to identify and so interrupt a beam otherwise not visible to the naked eye. The invention further provides a lift door system having the said plurality of emitters of a beams of electromagnetic radiation, and complementary receivers and indicators of a point of emission of a beam or of a point of reception of a beam so as to provide a visible identity for the existence of a beam to enable a user to identify and so interrupt a beam otherwise not visible to the naked eye. Preferably, the indicators are a series of LED's.

Description

OPERATING INDICATION METHOD AND APPARATUS

This invention relates to an operating indicator. In particular it is concerned with the provision of a means whereby the existence of at least two locations can be indicated 5 with which a predetermined operating condition exists as distinct from an adjacent location where the predetermined position does not exist.

A known problem with lift operation is the need for users to be clear as to the consequences of particular actions arising in the course of lift operation. One particular 10 problem arises in connection with door closure. With the lift door or doors open passage into and out of the lift is readily undertaken. However in the event that the lift door/e start to close inexperienced users become unsure whether it is safe to pass through the closing gap or whether, for example, 15 In the field of lift operation it is known to provide one of a number of sensing means

whereby the closure of lift doors can be stopped or reversed in the event that a foreign body such as a person, animal or article lies in, or enters, the path of a lift door as it closes. 20 Typically in one existing system the leading edge of a lift door has mounted in it a projecting strip or pad which, on contacting an article in the path of the closing door, generates a signal providing for the closing motion of the door to be reversed. In this version any point on the length of the strip or pad will be sensitive to an intrusion.

25 In another existing system a lift door is equipped with a collection of electromagnetic wave (typically infra red) beam emitters and complementary a door or frame member forming an opposite boundary to the lift entry is equipped with a corresponding collection of receivers for the emitted beams each receiver being directed towards an emitter. Variants on this system include ones where emitters (and receivers) are 30 provided on both doors. In use an invisible network of emitted beams extends across the entry space to the lift. As the door or doors close the entry of an intruding object

À e;e À into the entry space results in a blanking of beam transmission between at least one emitter/receiver pair. Such blanking results in the generation of a control signal providing for the closing motion of the door to be stopped and reversed. In this second example it will be apparent that the intrusion sensitive area represented by an emitted 5 beam is spaced apart from its neighbour in the emitter series. In this way the region of the entry in the path of a closing door has extending across it a sequence of spaced beams sensitive to an intruding object and an interposed sequence of insensitive regions between the beams. If an article intrudes into an insensitive region then a door control signal will not be generated. Consequently a sufficient emitter/receiver pairs 10 should be provided to ensure a resulting beam network in which the probability of any credible intrusion cutting at least one beam is high. In what follows this type of beam emitting system is referred to as being 'of the type described'.

According to a first aspect of the present invention there is provided a method of 15 operating a lift door system wherein a plurality of emitters provide a series of beams of electromagnetic radiation, such as of infra red, are directed from one side of a gap of variable size to the other side to the one side where the beams can be received by a complementary series of receivers; Ike gap providing for access to a lift car; characterized by the step of identifying by an indicator a point of emission of a beam as 20 aforesaid or of a point of reception of a beam so as to provide a visible identity for the existence of a beam as aforesaid to enable a user to identify and so interrupt a beam otherwise not visible to the naked eye.

According to a second aspect of the present invention there is provided a lift door 25 system wherein a plurality of emitters of a beams of electromagnetic radiation, such as of infra red, are directed from one side of a gap of variable size to the other side to the one side where a beam from one emitter in the plurality can be received by a complementary receiver a plurality thereof; the gap providing for access to a lift car; characterized by an indicator at a point of emission of a beam as aforesaid or of a point 30 of reception of a beam so as to provide a visible identity for the existence of a beam as

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aforesaid to enable a user to identify and so interrupt a beam otherwise not visible to the naked eye.

An exemplary embodiment of the invention will now be described with reference to 5 the accompanying drawing of part of a lift installation of which the sole drawing is view of a lift location on a floor of a building with the lift door partially open.

The drawing shows floor 11 of a building with wall 12 behind which is a lift shaft in which a car 13 can move between floor 11 and other floors. Access to the car 13 is by 10 way of an entry 14 which is normally closed by a sliding door 15 in the form of two telescoping leaves 15A, 15B.

Gap 17 is bounded on one side by leading edge 16 of leaf 15A. The leading edge 16 has mounted in it an array EA of infra red emitters spaced along, and set back slightly 15 from, the leading edge 16. On its other side gap 17 is bounded by a fixed column 18 against which the door 15 when the gap 17 is closed. Each emitter in the array EA, typically emitter E1, serves to direct an infra red beam across the gap 17 to a corresponding receiver, typically receiver R1, in a complementary receiver array RA installed in the column 18. The paths of infra red beams between the arrays is shown 20 by dashed lines, typically line L1 between emitter E1 and receiver R1. In this case the emitter array EA is installed on one side of gap 17 and the receiver array RA on the opposite side of the gap 17. In an alternative embodiment there can be emitter arrays disposed on both side of the gap with complementary receiver arrays on both sides of the gap 17. While the gap 17 exists (that is to say for as long as the door 15 does not 25 abut the column 18) the paths of the infra rays between the various arrays result in a net like mesh of beams rather than, as shown here, a parallel set of beams.

The beams of infra-red emissions are invisible to the naked eye. For many lift users the fact of the existence of a safety system is assumed and entering a closing gap does not 30 present a problem since such a user is aware that in the event the closing door, or in the cases of a pair of opposing doors, even if driven into contact with the body of the

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person or something they are carrying or drawing will not result in the door being driven into closer contact or the triggering off of anomalous lift car behaviour.

However for users lacking experience or confidence the existence of a safety system whose significant elements are invisible leads to a unwillingness to use the system or at 5 least to a waste of time until the lift car returns and provides a fully open door for access. There is provided on the outside of leading edge 16 a series 20 of light emitting diodes ('LED's') which indicate the position of each emitter in array EA. The series is directed 10 outwardly, that is to say at right angles to the outside surface of leaf 15A, rather than across the gap 17. A corresponding series can also be provided on the column 18 to indicate the position of each receiver in array ER. The purpose of the series 20 is to indicate clearly to a person approaching the gap 17 from outside the lift where a beam emitter or receiver is placed. In the event the gap 17 is closing then the person can place 15 his hand or some other object in the gap 17 near the leading edge 16 at the height of a selected LED in the series 20 array confidently knowing that as a result the beam extending from the indicated emitter will be interrupted and the lift door control system will operate so as to stop the closing of door 15 and start to open it. This enables the person to enter the car without coming into contact with the door 15 or column 18.

In this case the series 20 of LED's do not function as active members which sense the presence of an intrusion but as passive indicators showing where active members exist which can be caused to operate to change a current operating event (such as door closing). In an alternative embodiment the series 20 could include or be associated with 25 active elements having a number of possible effects for example the generation of light or sound signals or recorded messages.

The use of the series of LED's as described amongst other things serves to overcome the problem outlined at the start of the specification by providing reassurance to a user

30 who is inexperienced, poorly co-ordinated or diffident.

Claims

1 A method of operating a lift door system wherein a plurality of emitters provide a series of beams of electromagnetic radiation, such as of infra red, are directed from one side of a gap of variable size to the other side to the one side where the beams can be received by a complementary series of receivers; the gap providing for access to a lift car; characterized by the step of identifying by an indicator a point of emission of a beam as aforesaid or of a point of reception of a beam so as to provide a visible identity for the existence of a beam as aforesaid to enable a user to identify and so interrupt a beam otherwise not visible to the naked eye.

2 A lift door system wherein a plurality of emitters of a beams of electromagnetic radiation, such as of infra red, are directed from one side of a gap of variable size to the other side to the one side where a beam from one emitter in the plurality can be received by a complementary receiver in a plurality thereof; the gap providing for access to a lift car; characterized by an indicator at a point of emission of a beam as aforesaid or of a point of reception of a beam so as to provide a visible identity for the existence of a beam as aforesaid to enable a user to identify and so interrupt a beam otherwise not visible to the naked eye.

3 A lift door system as hereinbefore described with reference to the accompanying drawings.