GB2231081A - Ladder extending device - Google Patents

Abstract

A device for use in extending a multi-stage ladder, is elongate and rigid, having a tail end 12 for manual gripping by an operator and head end 14 which has first 22 and second 26 engagement means for engagement with a ladder stage in a way which permits the stage to be extended relative to the remainder of the ladder, the separation between the first 22 and second 26 engagement means being variable to provide for ready engagement, preferably with the rungs of the ladder stage. The engagement means may be spring-biassed either to bring them together or to separate them. <IMAGE>

Description

LADDER EXTENDING DEVICE The present invention relates to a device for use in extending multi-stage ladders.

Extending a multi-stage ladder tends to give rise to difficulties and to danger, particularly since the ladder must be extended when in a more or less vertical condition due to its weight and length. As a result of the impracticality in extending the ladder in a more or less horizontal condition, the ladder is often first placed against a wall in its approximate position of use and then extended. The user can only extend the ladder to a certain extent from a position standing on the ground adjacent the foot of the ladder. The user then often ascends the ladder until he or she can reach the lower end of the partially-extended second stage before perking the ladder away from the wall and extending it further before it falls back into contact with the wall.

Whilst an experienced workman can do this sucessfully, it is nevertheless a dangerous practice which can result in personal injury and damage to the ladder. Moreover, the unskilled user finds the procedure difficult, making it even more dangerous.

Furthermore, the procedure is not possible when the wall has a window or other obstructing feature where the ladder would contact during the procedure.

My UK Patent Application 8800086 discloses a device for use in extending a multi-stage ladder.

According to the present invention there is provided a device for use in extending a multi-stage ladder, the device being elongate and rigid, having a tail end for manual gripping by an operator and a head end which has first and second engagement means for engagement with a ladder stage in a way which permits the stage to be extended relative to the remainder of the ladder, the spearation between the first and second engagement means being variable.

Preferably the engagement means engage the rungs of the ladder stage.

Preferably, the device further includes means for retaining the engagement means in an engaging position.

Advantageously, the device includes resilient biasing means for biasing the first and second engagement means into an engaging position. The biasing means may comprise a tension spring connected to at least one of the engagement means, which means is movable due to the biasing force of the tension spring.

A compression spring could however be employed to bias the engagement means into an engaging position.

It should be understood that the biasing means may either tend to decrease or tend to increase the separation between the engagement means. The variation in the separation usually occurs in the vertical direction when the device is in use.

Thus when engaging the rungs, the first and second engagement means may be located inbetween the engaged rungs or they may be located on opposite sides of the engaged rungs.

Preferably, one of the engagement means is fixed against movement relative to the device.

The invention is described further hereinafter, by way of example only, with reference to the drawings in which: Fig 1 illustrates a side elevation of a ladderextending device embodying the present invention; and Fig 2 illustrates a side elevation of the head end of the device of Fig 1.

The ladder-extending device 10 illustrated in Fig 1 comprises of a tubular member 16 having a tail end 12 and a head-end 14. In the illustrated example, the tubular member 16 has a length of 1 metre and a width of 15 cm. The tail end 12 is arranged for gripping by the person using the device, and as such includes a handgrip 18 formed of plastics or other suitable material. The tubular member 16 is formed of aluminium so as to minimise the weight of the device. A collar 20 is rigidly fixed in the region of the end of the tubular member 16 remote from the tail-end 12.

A bracket 22 extends from the collar 20 and when the device 10 is disposed vertically forms a cradle bracket for supporting a rung of a ladder.

A cylindrical insert 24 extends from the end of the tubular member 16 remote from the handgrip 18. A second bracket 26 extends from one end of the cylindrical insert 24 such that the receiving portion of the bracket 26 faces the receiving portion of the bracket 22. As can be seen, the first and second brackets 22, 26 are disposed in mutually opposite locations so that they can each engage a respective different rung of a ladder portion. As illustrated in the drawings, the separation between the brackets is less than the separation of adjacent rungs of a ladder.

The cylindrical insert 24 has a slot extending along the longitudal axis thereof, which slot (not shown in the drawings) receives a guide portion 36 (as seen in Fig 2) of a guide member 28. The guide member 28 prevents rotation of the cylindircal insert 24 in the tubular member 16 and thus maintains the first and second brackets 22, 26 in a mutually opposite location.

Fig 2 illustrates the head end of the device 10 in greater detail. As can be seen, and as described previously, the cylindrical insert 24 is received in the end of the tubular member 16 remote from the hand grip 18 and its movement is guided therein by the guide portion 36 of the guide member 28. Further, the head end 14 of the device 10 includes a tension spring 30 secured at one end to the cylindrical insert 24 by means of a fixing pin 32. The other end of the tension spring 30 is secured to the tubular member 16 by means of a fixing pin 34. As such, the first and second brackets 22, 26 are biased towards each other.

The ladder extending device 10 is used as follows to extend a two stage ladder which each has the usual retaining means retaining the stages in different relatively extended positions.

The unextended ladder is first propped against a wall in its approximate position of use and the second stage of the ladder extended relative to the first stage to an extent which an operator standing on the ground adjacent at the foot of the ladder can easily achieve.

The ladder extending device is then attached to the lower end of the second stage of the ladder by first hooking the brackets 26 over one of the rungs of the second stage of the ladder. Since the separation between the first and the second brackets 22, 26 is less than a separation between adjacent rungs on the ladder, the separation between the brackets 22, 26 must be increased so as to allow the bracket 22 to engage under one of the other rungs of the second stage of the ladder. This is achieved by drawing the tubular member 16 downwards so as to extend the tension spring 30 and thus increase the separation between the brackets 22, 26 . Once a suitable separation is achieved, the bracket 22 can be hooked under a rung and the operator can reduce the force exerted on the tubular member 16 so as to allow the tension spring 30 to move the brackets 22, 26 in a direction towards each other. The strength of the tension spring 30 is sufficient to maintain engagement between the first and second brackets 22, 26 and the respective rungs as the ladder is extended. This is particularly advantageous since the extension of the ladder involves not only vertical movement of the second ladder stage, but also lateral movements of the base region thereof as the retaining means for retaining the stages of the ladder in different relative extended positions are disengaged and then re-engaged.

The invention is not restricted to the details of the foregoing embodiment. For example, the brackets 22, 26 could be arranged so that they fit in between two adjacent rungs, and the separation between the brackets is therefore increased so as to engage the device with the ladder stage. Also, engagement need not necessarily be made to adjacent rungs.

Claims (13)

1. A ladder extending device comprising an elongate and rigid body having a tail end for manual gripping by an operator and a head end which has first and second engagement means for engagement with a ladder stage in a way which permits the stage to be extended relative to the remainder of the ladder, the separation between the first and second engagement means being variable.

2. A device as claimed in claim 1, wherein the engagement means are arranged to engage the rungs of the ladder stage.

3. A device as claimed in claim 1 or 2, including retaining means for maintaining the engagement means in a ladder engaging position.

4. A device as claimed in claim 1, 2 or 3, including biasing means for biasing the engagement means towards the engaging position.

5. A device as claimed in claim 4, wherein the biasing means comprises a spring means.

6. A device as claimed in claim 4 or 5, wherein the biasing means operatively engages one of the engagement means.

7. A device as claimed in claim 4, 5 or 6, wherein the biasing means acts so as to decrease the mutual separation of the engagement means.

8. A device as claimed in claim 7, wherein the biasing means comprises a tension spring.

9. A device as claimed in claim 4, 5 or 6, wherein the biasing means acts so as to increase the mutual separation of the engagement means.

10. A device as claimed in claim 9, wherein the biasing means comprises a compression spring.

11. A device as claimed in any of claims 1 to 8, wherein the engagement means form jaw means.

12. A device as claimed in any preceding claim, wherein one of the engagement means is fixed against movement relative to the body.

13. A ladder extending device substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.