GB2372280A

GB2372280A - Safety device for sliding door of lift

Info

Publication number: GB2372280A
Application number: GB0103993A
Authority: GB
Inventors: Sharad Ganesh Pradhan
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-02-19
Filing date: 2001-02-19
Publication date: 2002-08-21
Also published as: GB0103993D0

Abstract

A safety device for the bottom of a sliding door 1 of a lift comprises a plate 5 or other component which projects down into the track 2 in which the guide shoe 3 runs. The plate 5 does not normally engage the track but, in the event of the shoe 3 breaking off, the plate engages the track to prevent the door from swinging into the lift shaft. The plate may be replaced e.g. by pins or bolts.

Description

DEVICE FOR IMPROVED SAFETY AGAINST IMPACT FOR HORIZONTALLY SLIDING DOORS FOR LIFT [ELEVATOR] SHAFTS.

This invention relates to the improvement in safety of the horizontally sliding doors used for or installed in the elevator shafts (lift shafts) in case of failure or breakage of the bottom guide shoes by incorporating or addition of a component that is referred to in this application as "Safety Plate".

Note: the word"lift"used in this application in connection with words such as"lift shaft","lift door","lift entrance","lift lobby"etc has the same meaning as"elevator" [an alternative word for lifts] used in connection with the similar words.

Figurer 1. shows a typical horizontally sliding door assembly. The tops of door panels (1) are fixed to door hanger assembly and top track (10). The bottom part of the door panels incorporates a number of guide shoe assemblies (3) that slide along the bottom track (2).

Both the door hanger assembly and the bottom track assembly are fixed to the entrance frame (13) which itself is built into the lift shaft structure. However a possible dangerous situation can arise if due to any reason a failure or breakage of the guide shoe assembly occurs.

In case of a heavy impact from the landing side to the face of the door panels, it is possible the guide shoe assembly at the bottom to break allowing the door panel to swing into the lift shaft as shown in Figure 2. I f this happens particularly when the lift is away from that particular landing; any person impacting on the door can be thrown into the lift shaft and may suffer injury or death. In Figure 2 item 16 indicates the inside face of a lift shaft and item 15 indicates the landing side of the entrance or the lift lobby.

According to the present invention by incorporating an additional or integral Safety Plate a degree of additional safety is provided against the breakage of guide shoe in impact condition or even where the guide shoe comes apart for any other reason.

The specific embodiment of the invention will now be described by the way of example with the accompanying drawings [Figure. 3,4, 5,6, 7,] in which: Figure 3 shows in perspective the Safety Plate (as used in conjunction with a standard guide shoe assembly) in relation to some of the standard parts of the door assembly shown in Figure. 1.

Figure. 4 shows a possible alternative design of the Safety Plate for use in conjunction with a standard guide shoe assembly or alternatively on its own in any other convenient position without a reference to any guide shoe position.

Figure 5 shows another possible variation where the Safety Plate is built as an integral part of the door panel frame requiring no additional fixing.

Figure 6 shows a typical Safety Plate in normal working position.

Figure 7 shows a typical Safety Plate under impact conditions [with the guide shoes broken or fallen apart] ; preventing the door panel from swinging into the lift shaft.

Referring to Figure 3 the Safety Plate (6) comprises of a Plate or a bracket made from a suitable material and has protrusions in the form of"tongues"that engage into the slots (7) made into the bottom panel of the door to receive the Safety Plate. Security screws (8) hold the Safety Plate in place when fixed using the threaded holes (9). The normal guide shoe is assembled using the Safety Plate as shown thus allowing the tongues of the Safety Plate to move along the bottom track (2) when the door panel slides along with the guide shoe assembly (3). The total number of Safety Plates required per entrance door will depend upon the design, type and dimensions of the entrance doors. Such a Safety Plate can be incorporated into the design of a horizontally sliding doors or can be retrofitted to the entrances of existing lift shaft installations.

Various alternative designs of this embodiment of the safety Plate are possible as shown in Figure 4 and Figure 5. In Figure 4 the protrusions are in the form of pins. Such a plate can be used either in conjunction with an existing guide shoe position or without any reference to the guide shoe in any convenient position. When using this alternative design the bottom panel (1) requires holes instead of slots to accommodate the projecting pins. Figure 5 shows another embodiment of the Safety Plate as an integral part of the door panel with pins (17) projecting from the lower face of the panel (1). Another alternative to pins is also shown in Figure 5, where threaded bolts or screws (18) are used instead of pins.

Existing lift entrance doors can also be retrofitted with threaded bolts or screws similar to the manner shown in Figure 5 to achieve improvement in safety against impact.

Figure 6 shows a typical safety device in normal working condition. Under normal working conditions the protrusions, tongues, pins or bolts of the Safety Plate do not contact any part of the recess of the bottom track (2) and have a passive role. In case of breakage of the guide shoe due to impact (such as an impact on to the face of the door panel from the landing side) or for any other reasons the guide shoe assembly may be rendered ineffective due to damage or breakage. In such a case the door panel is prevented from swinging into the lift shaft as the protrusions or tongues stop against the recess of the bottom track (2). Figure 7 shows the action of the safety device under impact condition. The manner in which the device works as a safety device is the same whether it is in the form of a separate component [plate or a bolt or screw] or as an integral part of the door.

Claims

CLAIMS 1. A safety device here referred to as"Safety Plate"that can be introduced into or incorporated into any typical horizontally sliding door for a lift entrance to provide safety against failure of the bottom guide shoes and preventing the door panel from swinging or opening into the lift shaft.
2. A safety device that while normally staying in a passive state, will actively prevent the panel of a horizontally sliding door of a lift entrance from swinging into or opening into a lift shaft on impact from the landing side into the door panel.
3. A safety device as claimed in 1 and 2 with alternative designs that can be used in conjunction with a normal guide shoe or without any reference to the guide shoe in any convenient position in the door panel.
4. A safety device as claimed in 1,2 and 3 above which could be incorporated into a new door design or retrofitted to existing doors to improve the safety.
5. A safety device as claimed in 1,2, 3, above with protrusions, projections, tongues or pins built or made as an integral part of the original door panel or new design of door panel instead of using separate components as per claim 1,2, 3, or 4.
6. A safety device as claimed in 1,2, 3 above that can be retrofitted to existing lift entrance doors to improve safety against impact or failure of bottom guide shoes.
7. A safety device as claimed in 1,2, 3, 4 above but in the form of a threaded bolt or screw.
8. A device as claimed in 1,2, 3,4, 5,6, 7and 8 above; that offers improved safety to the public in the lift lobbies of lifts and at lift landing entrances with horizontally sliding doors against accidental impact by not allowing the door panel to swing into the lift shaft.