GB2551957A

GB2551957A - A Safety Ladder

Info

Publication number: GB2551957A
Application number: GB1609044.1A
Authority: GB
Inventors: Ernest Woof Joseph
Original assignee: Fullgate Ltd
Current assignee: Fullgate Ltd
Priority date: 2016-05-23
Filing date: 2016-05-23
Publication date: 2018-01-10
Anticipated expiration: 2036-05-23
Also published as: GB2551957B; GB201609044D0

Abstract

Safety ladder for use, in particular, in an elevator shaft comprises a ladder part 11 and two side rails 12a 12b connected by a plurality of rungs 13, four positioning arms 16 and a wall mounted frame. Each side rail is pivotally connected to one end of two of the position arms at points spaced apart along the side rail. The frame is pivotally connected to the other ends of the positioning arms. The ladder may further comprise a manual lock which may comprise an arm that rotates between a locked and unlocked position and may be displaced either side of the safety ladder. The ladder may further comprise a micro-switch which may be in communication with the electronic control system of the lift. The ladder may further comprise a gas strut which is attached to the frame and a cross part of the upper arm.

Description

(54) Title of the Invention: A Safety Ladder Abstract Title: Safety ladder (57) Safety ladder for use, in particular, in an elevator shaft comprises a ladder part 11 and two side rails 12a 12b connected by a plurality of rungs 13, four positioning arms 16 and a wall mounted frame. Each side rail is pivotally connected to one end of two of the position arms at points spaced apart along the side rail. The frame is pivotally connected to the other ends of the positioning arms. The ladder may further comprise a manual lock which may comprise an arm that rotates between a locked and unlocked position and may be displaced either side of the safety ladder. The ladder may further comprise a micro-switch which may be in communication with the electronic control system of the lift. The ladder may further comprise a gas strut which is attached to the frame and a cross part of the upper arm.

At least one drawing originally filed was informal and the print reproduced here is taken from a later filed formal copy.

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Fig. 6

A Safety Ladder

The present invention relates to a safety ladder preferably but not exclusively for a lift shaft.

Previously disclosed lift shaft ladders take up a lot of space in the clearances between the lift car and the shaft wall. There are also issues with the use of such ladders in regard to the safety of operations including ease of access. Furthermore, existing shaft ladders are mounted directly on the shaft wall often at a considerable distance from the access point. When the ladder is removed from the mounting, the weight of the ladder would have to be lifted from its retainer to be used. This also causes problems when replacing the ladder.

It is an aim of the present invention to provide a safety ladder which is stable, has higher safety and can be installed quickly and easily.

Accordingly the present invention is directed to a safety ladder comprising a ladder part having two side rails connected by a plurality of rungs, four positioning arms and a wall mounting frame, in which each side rail is pivotally connected to one end of two of the position arms at points spaced apart on the side rail and the wall mounting frame is pivotally connected to the other ends of the position arms. This provides the advantage that the safety ladder can be mounted on a shaft wall and by use of the arm, the ladder part can be deployed forward in a safe and stable manner. Thus bringing the ladder in use close to the access point while allowing safe storage against the wall when not in use.

In a preferred embodiment, the safety ladder further comprises a manual lock which holds the safety ladder in a safe and secure closed-flat position when not in use. This enables easy locking and unlocking if necessary using an appropriate pole and prevents accidental deployment of the safety ladder when the lift is in use.

Preferably, the manual lock is a simple mechanical lock comprising an arm which is rotatable between an upright unlocked position to a locked perpendicular position around an axis when the safety ladder is not in use.

Advantageously, the end of the arm of the manual lock is equipped with a movable locking bar. This allows an easy handling to lock the safety ladder.

Preferably, the manual lock is fitted to either side of the safety ladder to allow for easy access and release of the lock.

Preferably, the ladder can be fitted on either or both left and right side walls of shaft.

In a preferred embodiment, the safety ladder further comprises a micro switch which is attached to the safety ladder and monitors the position of the safety ladder. This provides the benefit of stopping the lift while a user is conducting maintenance operations on the deployed safety ladder.

Advantageously, the micro switch is in communication with the electronic control system of the lift and comprises the actuator on one of the arms and the roller lever on the ladder part. This enables to open the circuit and to prevent the lift from moving while the safety ladder is deployed.

Preferably, the micro switch operates only when the safety ladder is in a closed-flat to the wall safe position.

In a preferred embodiment, a gas strut is attached to the frame and a cross part of the upper arm. This enables to counterbalance the lowering of the ladder part.

Advantageously, the spaced positions of the arms on the side rails are such that the distance between the spaced positions is greater than or equal to the length of the arms. This provides a better stability when the safety ladder is deployed and allows for the safety ladder to have a smaller fingerprint when in the non-used position.

Advantageously, the safety ladder includes stop means to limit the movement of the arms such that when deployed they are preferably perpendicular to the frame. This ensures when deployed the safety ladder forms a stable square, rectangular or parallelogram shape. The stop means can be the bottom of the ladder part which rest on the floor of the lift shaft.

Alternatively or in addition, the arms at their frame end are pivot mounted on their top corner and the end of the arm rests when deployed against the lift shaft thus acting as stops.

Likewise, the gas strut can be used to enable the safety ladder to be stopped in the desirable position against the lift shaft.

Preferably, the joints are made from steel bushs and rivet pins on the frame side of the safety ladder and retaining clips and bolts which pass through holes in the ladder part, frame and arms. This provides a solid and simple attachment between all the parts.

In a preferred embodiment, the material for the manufacture of the safety ladder is a non-combustible material, advantageously galvanising steel or aluminium to give a maintenance free long lif e .

This configuration provides an extremely stable safe and speedy method of accessing the pit of the lift shaft.

An example of a safety ladder made in accordance with the present invention will now be described hereinbelow with reference to and as shown in the attached drawings, in which:

Figure 1 is a perspective view of a safety ladder mounted on a shaft wall according to the present invention;

Figure ladder	2 is shown	an in	enlarge view Figure 1;	of	a manual	lock	for	the	safety
Figure	3 is	an	enlarge view	of	a micro	switch	of	the	safety
ladder	shown	in	Figure 1;

Figure 4 is a side perspective view of the safety ladder shown in Figure 1 in a semi deployed position;

Figure 5 is a side perspective view of the safety ladder shown in Figure 1 in working position; and

Figure 6 is a cross-sectional of the shaft which the safety ladder shown in Figure 1 is fitted.

Figure 1 shows the safety ladder 10 with a ladder part 11 having two side rails 12a and 12b connected by a plurality of rungs 14, being coupled to four positioning arms 16. The ladder part 11 can be a conventional ladder or one made specifically for this purpose. Two positioning arms 16 are attached to each side rail

12a and 12b of the ladder part 11 at one of their ends at spaced apart positions by joints 18, so that the distance between the joints 18 is greater than or equal to the length of the arms 16.

The other ends of the positioning arms 16 are attached to a wall mounting frame 20 by joints 22. The joints 18 and 22 formed so as to allow rotational movement of the arms 16 relative to the frame 20 and the ladder part 11. The joints 18 and 22 in this case are made from steel bushs and rivet pins on the frame side of the safety ladder and retaining clips and bolts which pass through holes in the ladder part 11, frame 20 and arms 16. The safety ladder 10 is equipped with a manual lock 24 which holds the ladder part 11 and arms 16 in a safe and secure closed-flat position against the frame 20 mounted on the shaft wall when not in use. The safety ladder 10 is further equipped with a micro switch 26 which prevents the lift 34 to work while the safety ladder 10 is deployed. Furthermore, a gas strut 28 is attached to the frame 20 and a cross part of the upper arms 16a to counterbalance the lowering of the ladder part 11.

Figure 2 shows the manual lock 24 of the safety ladder 10 in greater detail. The lock 24 is a simple mechanical lock comprising an arm 25 which is rotatable between an upright unlocked position A to a locked perpendicular position B around an axis C when the ladder 10 is not in use. The end of the arm is equipped with a movable locking bar 27.

Figure 3 shows a micro switch 26 attached to the safety ladder which monitors the position of the safety ladder 10 in greater detail. The micro switch 26 is an electrical component which is connected at the electronic control system of the lift 34. The micro switch 26 comprises the actuator 26a on one of the arms and the roller lever 26b on the ladder part 11 so when the two parts are not in communication, this is transmitted to the control system which prevents the lift 34 from moving.

Figure 4 shows the safety ladder 10 being deployed to a working position by pulling it down after having removed the manual lock

24. The gas strut 28 counterbalances the lowering and the lifting of the safety ladder 10. The arms 16, which create a parallelogram, are swung to reach a perpendicular position as shown in Figure 5.

Figure 5 shows the safety ladder 10 entirely deployed to a working position. The safety ladder 10 includes stop means 29 and 31 to limit the movement of the arms so that the positioning arms 16 are ideally extended perpendicularly to the ladder part and the frame 20 when deployed. Thus, positioning the ladder

- 8 part 11 vertically and parallel to the wall. The four arms 16, ladder part 11 and frame 20 form a square, rectangular or parallelogram shape which is a rigid structure providing a stable position for the user. The stop means 29 and 31 can be the bottom of the ladder part 29 which rest on the floor of the lift shaft 30. Alternatively or in addition, this can also be the arms at their frame end 31 which are pivot mounted on their top corner so that the end of the arms rest when the safety ladder 10 is deployed against the lift shaft 30. Likewise, the gas strut 28 can also act in this role.

Figure 6 shows the safety ladder 10 located on one side of the shaft 30 close to the lift doors 34. The clearance of the lift car 32 from the shaft wall 30 is a distance y which is greater than the depth x of the safety ladder 10 when not deployed. The lift car 32 is stopped at a higher floor when it is desired to use the safety ladder 10. The doors 34 of the lift shaft 30 are opened and a user can easily reach the safety ladder 10 and deploy it for necessary work.

Claims

Claims 1705 17

1. A safety ladder comprising a ladder part having two side rails connected by a plurality of rungs, four positioning arms

5 and a wall mounting frame, in which each side rail is pivotally connected to one end of two of the position arms at points spaced apart on the side rail and the wall mounting frame is pivotally connected to the other ends of the position arms.

10

2. A safety ladder according to Claim 1, which further comprises a manual lock which holds the safety ladder in a safe and secure closed-flat position when not in use.

3. A safety ladder according to Claim 2, in which the manual

15 lock is a simple mechanical lock comprising an arm which is rotatable between an upright unlocked position to a locked perpendicular position around an axis when the safety ladder is not in use.

20

4. A safety ladder according to Claim 3, in which the end of the arm of the manual lock is equipped with a movable locking bar

1705 17

5. A safety ladder according to any one of Claims 2 to 4, in which the manual lock is fitted to either side of the safety ladder .

5

6. A safety ladder according to any preceding claim, in which the ladder can be fitted on either or both left and right side walls of shaft.

7. A safety ladder according to any preceding claim, which

10 further comprises a micro switch which is attached to the safety ladder .

8. A safety ladder according to Claim 7, in which the micro switch is in communication with the electronic control system

15 of the lift and comprises the actuator on one of the arms and the roller lever on the ladder part.

9. A safety ladder according to Claim 7 or Claim 8, in which the micro switch operates only when the safety ladder is in a

20 closed-flat to the wall safe position.

10. A safety ladder according to any preceding claim, in which a gas strut is attached to the frame and a cross part of the upper arm.

1705 17

11. A safety ladder according to any preceding claim, in which the spaced positions of the arms on the side rails are such that the distance between the spaced positions is greater than or equal to the length of the arms.

12. A safety ladder according to any preceding claim, in which the safety ladder includes stop means to limit the movement of the arms such that when deployed they are preferably perpendicular to the frame.

13. A safety ladder according to any preceding claim, in which the arms at their frame end are pivot mounted on their top corner and the end of the arm rests when deployed against the lift shaft.

14. A safety ladder according to Claim 10 or any one of Claims

11 to 13 as read appendant thereto, in which the gas strut can be used to enable the safety ladder to be stopped in the desirable position against the lift shaft.

15. A safety ladder according to any preceding claim, in which the joints are made from steel bushs and rivet pins on the frame side of the safety ladder and retaining clips and bolts which pass through holes in the ladder part, frame and arms.

16. A safety ladder according to any preceding claim, in which the material for the manufacture of the safety ladder is a noncombustible material.

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Intellectual

Property

Office

GB 1609044.1

1-16

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