GB2355481A

GB2355481A - Ladder extending device

Info

Publication number: GB2355481A
Application number: GB9923684A
Authority: GB
Inventors: David Atkinson; Tom Harrison
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-10-08
Filing date: 1999-10-08
Publication date: 2001-04-25
Also published as: GB9923684D0

Abstract

The device comprises an elongate, preferably telescopic pushing element 6 that can be used to engage either a rung 16 of, or a pushing element locator 2 secured to one side of, the upper portion 12 of the ladder 10. The device also includes a holder 4 for the pushing element when it is not in use and which is secured to the ladder, preferably by threaded bars 20 that extend through the hollow rungs of the ladder.

Description

2355481 "Ladder Extension Device" The invention relates to a ladder

extension device and to a ladder extension device in combination with a ladder.

As is well known, most general purpose ladders fall into one of two categories, being extension ladders and so called "step-ladders". The extension ladder, to which this invention pertains, comprises upper and lower ladder sections, each comprising a pair of generally parallel, spaced apart rails having a plurality of rungs extending therebetween. The upper and lower extension ladder sections are slidably mounted such that the upper ladder section is slidably extendible with respect to the lower ladder section. In this manner, the upper ladder section can be extended, either fully or partially, to provide additional height when in use, and then slidably retracted for storage.

Although the extension ladder is widely available in a multitude of forms, it suffers from certain disadvantages. The extension ladder can be extended to heights of five to seven metres or more for use, but then retracted to a relatively manageable three to four metres in length for transport and storage. However, a major disadvantage lies in the fact that, to extend the ladder while lying on the ground makes it dangerous and difficult to raise the ladder to an in use position, being a substantially vertical position with a top edge of the parallel rails abutting a supporting wall or surface. A further difficulty following this is that, frequently, an extended height of the ladder will be unsuitable, and thus further adjustment of the in use height is required. Similarly, if an extension ladder is initially propped against the supporting surface in the storage state before being extended, this again leads to dangers and difficulties associated with extending the ladder higher than a person at ground level can reach. While a block and tackle type winching mechanism alleviates these problems, an increase in manufactured cost coupled with the necessity to change a design of a ladder to incorporate the winching mechanism, in conjunction with the consumer having to purchase an entirely new ladder system, only increases the disadvantageous aspects.

Therefore, the present invention sets out to provide a new and improved design for a ladder extension device which may overcome some or all of the above mentioned problems and which also provides other advantages. The invention is particularly applicable to extension ladders, such as used in general home maintenance, but the invention is not limited to this type of ladder and may also be applicable to other types of ladder.

According to a first aspect of the invention there is provided a ladder extension device comprising an elongate pushing member engagable by a user with the upper section of an extendible ladder or a part attached thereto so that the user can extend the ladder to a maximum or substantially maximum height from ground level, and a holder attachable to the ladder for supporting the pushing member when the pushing member is not in use.

Preferred and/or optional features of the first aspect of the invention are set out in claims 2 to 7.

According to a second aspect of the invention, there is provided a ladder extension device in combination with an extendible ladder having openended tubular rungs, the extension device comprising an elongate pushing member engagable by a user with the upper section of the ladder or a part attached thereto so that the user can extend the ladder to a maximum or substantially maximum height from ground level, and a holder, attached to the ladder by means extending through the rungs, for supporting the pushing member when the pushing member is not in use.

A preferred and/or optional feature of the second aspect of the invention is set out in claim 9.

According to a third aspect of the invention, there is provided a holder attachable to a ladder having hollow rungs, the holder comprising hollowrung attachment means receivable at least in part in the hollow rung, so that the holder is detachably mountable on the ladder.

The ladder extension device in combination with the ladder is highly advantageous in that it utilises an elongate pushing member, operated by the user of the ladder standing on the ground.

Another advantage lies in the pushing member being telescopically extendable. Consequently, even a tall extension ladder can be safely extended to at least a substantially maximum height by a user at ground level.

A further advantage is the provision of a holder, preferably attachable to the supporting lower section of the ladder, for receiving the pushing member during storage. Preferably, a pushing-member locator is also attachable to the upper section of the extendible ladder and releasably engages the pushing member, whereby the upper section can be safely raised to a desired height, that includes a maximum possible extension of the ladder, without the requirement of standing on the ladder.

Another advantage of the ladder extension device in combination with a ladder lies in the unique usage of the rungs of the ladder, whereby the holder and locator are securely attachable to the required portions of the ladder through the open ended tubular rungs of a majority of conventional ladders. This allows unhindered access to the rungs of the ladder by the feet of the user.

The invention will now be more particularly described, by way of example, with reference to the accompanying drawings, in which:

Figure 1 is an exploded perspective view of an embodiment of a ladder extension device according to the present invention; Figure 2 shows perspective views of ladder attachments used in the embodiment; Figure 3 is a partially cross-sectioned front elevational view showing one of the ladder attachments fixed through rungs of the ladder; Figure 4 is a perspective view showing a first part of a pushing member of the ladder extension device; and Figure 5 is a perspective view showing a second part of the pushing member.

Referring now to the drawings, the ladder extension device shown therein comprises a pushing-member locator 2 disposable on either side of an extendable upper section 12 of extension ladder 10; a holder 4 disposable on a supporting lower section 14 of the extension ladder 10; and a pushing member 6 releasably engagable with the locator 2 and the holder 4 as is required.

The locator 2 and holder 4 are securely attachable to the side of the ladder by two threaded bars 20 extending through through-holes 18 in rungs 16 and apertures 26 in the locator 2 and holder 4. Nuts 22 with washers 24 threadingly engage opposite ends of each threaded bar 20 to clamp the locator 2 and holder 4 to the upper and lower sections 12 and 14, respectively. As can be seen in Figure 3, bush-shaped spacers and bungs 28 are fixedly mounted by a further locking nut 22 and washer 24 on the threaded bars 20, being interposed between the upper and lower sections 12 and 14 and the locator 2 and holder 4. Each bung is received as a press-fit in corresponding rung through-hole 18 such that the threaded bars 20 and the locator -6 2 and holder 4 are resiliently held in place.

The pushing member 6 comprises an elongate ann selectively receivable by the locator 2 and the holder 4. The pushing member 6 is telescopically extendable, incorporating two elongate elements 62 and 66 slidably received by each other. The first elongate element 62 is of sufficient cross-section such that the upper end is receivable by the locator 2. A rung engagable element, typically in the form of a hook 64, is provided at or adjacent to the upper end of the first elongate element 62.

The second elongate element 66 is of sufficient cross-section such that the lower end is receivable by the holder 4 located on the support portion 14 of the ladder 10.

Both elongate elements 62 and 66 are supplied with corresponding apertures 68 and 70. Further apertures 72, 74 and 76 are provided adjacent to the upper and lower ends, respectively, of the elongate element 66, and corresponding apertures 42 and 44, as best seen in Figure 2, are provided adjacent to the upper end of the holder 4. Using a suitable nut and bolt arrangement located through apertures 72 and 44 (see Figure 1), key-chain locking pins 78 and 46, respectively, are depended therefrom.

When the pushing member 6 is required to be in a telescopically extended state, in order to ensure that the elongate elements 62 and 66 are securely interconnected, locking pin 78 is manually inserted through coaxially aligned apertures 68 and 70. If the pushing member 6 is required to be in a telescopically retracted state, in order to ensure that the elongate elements 62 and 66 are securely interconnected, locking pin 78 is manually inserted through coaxially aligned -7 apertures 68 and 74, with the second elongate element 66 inverted.

When required, several storage states exist in this embodiment for storing the pushing member 6. The pushing member 6 is storable on the ladder 10 by the holder 4 being receivable in the second element 66. If the pushing member 6 is in the telescopically extended state, then secure storage is effected by coaxial alignment of aperture 76 in elongate element 66 and aperture 42 in holder 4, and manual insertion of locking pin 46. Alternatively, if the pushing member 6 is in the telescopically retracted state, then secure storage is effected by coaxial alignment of aperture 70 in elongate element 66 and aperture 42 in holder 4, and manual insertion of locking pin 46.

In operation, the user initially stands the extension ladder 10 on the ground and props it against an. appropriate supporting surface in the vicinity of work to be carried out. The upper section 12 of the ladder 10 is raised by the user standing safely at ground level to a maximum height possible, dependent on a height of the user. The pushing member 6 is removed from the holder 4 and is telescopically retracted or extended as is required. The upper end of the first elongate element 62 of the pushing member 6 is then inserted into the lower end of the locator 2 by the user still standing on the ground until abutting on the threaded bar 20, whereby the user remaining at ground level is able to easily and safely extend the upper section 12 of the ladder 10 to any desired height up to the maximum extensible height of the ladder 10. The pushing member 6 can then be re-stored on the holder 4 while the ladder 10 is in use or put to one side ready for reuse. When the ladder 10 is no -8longer required, or should be moved to a new location, the upper section 12 can be safely lowered by the user from ground level by use of the pushing member 6 as described above.

Alternatively, the hook 64 can be used to reliably locate at least one rung 16 disposed on the upper section 12, thereby allowing the upper section 12 to be raised to a desired height should there be a reason for the locator 2 being inaccessible. Further, by use of the hook 64, other extension ladders may also be safely raised and lowered by a user standing at ground level, without the necessity of requiring the locator 2.

By use of the ladder extension device, an extension ladder can be safely raised and lowered under control by a user at ground level. Attaching means extending through the open-ended tubular rungs of alurninium ladders conveniently allow the locator and holder 2 and 4 of the ladder extension device to be disposed at the discretion of the user on the ladder, without producing dangerous or movement restricting projections in the path of a person using the ladder. Due to the locator 2, the elongate pushing arm 6 can be easily and surely engaged with the upper section 12 of the ladder 10, allowing safe and controlled extension and retraction thereof.

Due to the holder 4, the pushing arm 6 can be securely and conveniently stored. The telescopically extendable pushing member 6 allows any user standing at ground level to safely extend the upper section of any extension ladder to any desired height including a substantially maximum extensible height. The hook 64 on the pushing member 6 allows any user at ground level to safely extend the upper section of an -9 extension ladder to any desired height including a substantially maximum extensible height, irrespective of whether the locator 2 is provided thereon.

The embodiment described above is given by way of example only and various modifications will be apparent to persons skilled in the art without departing from the scope of the invention. For example, a single holder-locator can perform the function of both the locator 2 and holder 4. The locator 2 and holder 4 may not necessarily be restricted to only receiving the pushing member 6, and may be configured to be able to receive a caddy device.

Claims

_10CLAIMS

1. A ladder extension device comprising an elongate pushing member engagable by a user with the upper section of an extendible ladder or a part attached thereto so that the user can extend the ladder to a maximum or substantially maximum height from ground level, and a holder attachable to the ladder for supporting the pushing member when the pushing member is not in use.

2. A ladder extension device according to claim 1, wherein the pushing member is telescopically extendible and retractable.

3. A ladder extension device as claimed in claim 1 or claim 2, wherein the pushing member has a rung engagable element at or adjacent to its upper end for releasably engaging at least one rung of the ladder.

4. A ladder extension device according to any preceding claim, wherein the holder is attachable to the ladder by means extending through a throughhole in at least one rung of the ladder.

5. A ladder extension device according to any preceding claim, further comprising a pushing-member locator attachable to the upper section of the ladder for releasable engagement by the pushing member.

6. A ladder extension device according to claim 5, wherein the holder and the locator are independently attachable to the ladder by means extending through respective through-holes in at least two rungs of the ladder.

7. A ladder extension device according to any preceding claim, wherein the holder is attachable to the lower section of the ladder.

8. A ladder extension device in combination with an extendible ladder having open-ended tubular rungs, the extension device comprising an elongate pushing member engagable by a user with the upper section of the ladder or a part attached thereto so that the user can extend the ladder to a maximum or substantially maximum height from ground level, and a holder, attached to the ladder by means extending through the rungs, for supporting the pushing member when the pushing member is not in use.

9. A combination as claimed in claim 8, further comprising a pushingmember locator attached to the upper section of the ladder for releasable engagement by the pushing member.

10. A holder attachable to a ladder having hollow rungs, the holder comprising hollow-rung attachment means receivable at least in part in the hollow rung, so that the holder is detachably mountable on the ladder.

11. A ladder extension device substantially as hereinbefore described with reference to the accompanying drawings.