GB2416104A

GB2416104A - Tubular extension handle

Info

Publication number: GB2416104A
Application number: GB0415889A
Authority: GB
Inventors: Nicholas Gerald Grey
Original assignee: Grey Technology Ltd
Current assignee: Grey Technology Ltd
Priority date: 2004-07-16
Filing date: 2004-07-16
Publication date: 2006-01-18
Also published as: GB0415889D0

Abstract

A substantially rigid tubular extension handle 46 is provided for a hand-held battery-powered motor-driven electric tool. The tool comprises a hollow housing portion 10 adapted to demountably receive a battery pack (12 figure 1), and the tubular extension device 46 includes a first end portion 48 adapted to be demountably received in the hollow housing portion 10 of the tool in place of the battery pack (12) . The tubular extension device 46 also includes a second end portion 60 adapted to demountably receive the battery pack 12 therein, and electrical connection means (50, 52, 64, 66, 68 figure 4) between the first and second end portions, adapted for electrical connection of the battery pack 10 to a motor (34 figure 2) of the tool.

Description

J - 1 -

TUBULAR EXTENSION DEVICE

This invention relates to a device for use with a hand- held electric motor-driven tool and particularly, but not exclusively, a garden trimming tool.

Garden trimming tools are known which comprise an electric motor-driven cutting head on an elongate body which is held by a user by means of a handle provided at the opposite end of the elongate body to the cutting head. Such an arrangement enables the user to trim surfaces such as lawns and lawn edges while standing up.

However, there are applications where the use of a trimmer is required whilst the user is closer to the surface to be trimmed, for example whilst crouching in the garden for carrying out other garden maintenance activities such as weeding, or where the trimming of a surface requires the user to be relatively close to the surface for accuracy, for example trimming a shrub or hedge. Such applications have required provision of a separate trimmer, which is uneconomical.

The majority of trimmers are powered by means of mains power supplied via a power lead. Such power leads can often become entangled with themselves and items generally found in gardens, for example ornaments and i 2 garden furniture. Accidental damage to a power lead by the cutting head of a trimmer can also occur.

It is an object of the present invention to overcome or minimise the aforementioned problems.

According to the present invention there is provided a substantially rigid tubular extension device for a hand- held battery-powered motor-driven electric tool, the tool comprising a hollow housing portion adapted to demountably receive a battery pack, the tubular extension device comprising: a first end portion adapted to be demountably received in the hollow housing portion of the tool in place of the battery pack; a second end portion adapted to demountably receive the battery pack therein) and electrical connection means between the first and second end portions, adapted for electrical connection of the battery pack to a motor of the tool.

The battery pack and the first end portion of the tubular extension device may each have a substantially similar external configuration.

First manually-operable latch means, such as of spring loaded form, may be provided, adapted to cooperate between the hollow housing portion of the tool and either - 3 - the battery pack or the first end portion of the tubular extension device, for releasably securing the battery pack or the first end portion of the tubular extension device in the hollow housing portion of the tool.

Second manually-operable latch means, such as of spring loaded form, may be provided, adapted to cooperate between the second end portion of the tubular extension device and the battery pack, for releasably securing the battery pack in the second end portion of the tubular extension device.

The first and second latch means may both be of substantially the same form.

The electrical connection means may comprise electrical leads extending through the tubular extension device between the first and second end portions thereof.

Switch means may be provided at the second end portion of the tubular extension device and adapted to control supply of electric power from the battery pack to the tool. Such switch means may be of safety dual-action type and may incorporate a button which is required to be pressed before an operating lever is able to be actuated. - 4 -

First and second electrical contact means may be provided electrically connected to the electrical connection means at first and second end portions respectively of the tubular extension device, third electrical contact means being provided in the hollow housing portion of the tool, and fourth electrical contact means being provided on the battery pack, the third electrical contact means being adapted to be slidingly engaged by either the first or the fourth electrical contact means, the second electrical contact means being adapted to be slidingly electrically engaged by the fourth electrical contact means.

The first, second and fourth electrical contact means may each comprise two electrical contacts. The third electrical contact means may comprise three electrical contacts, a first one of which is engageable by one of the contacts of either the first or the fourth contact means, a second one of which is engageable by the other contact of the fourth contact means such that the tool is electrically supplied from the battery pack through a further switch means provided on the tool, when the battery pack is located in the hollow housing portion, and a third one of which is engageable by the other contact of the first contact means such that the further switch means on the tool is by-passed, when the first end portion of the tubular extension device is located in the hollow housing portion.

The further switch means may be of safety dual-action type and may incorporate a button which is required to be pressed before an operating lever is able to be actuated.

The hollow housing portion of the tool may comprise a handle portion for the tool when used without the tubular extension device.

The second end portion of the tubular extension device may be adapted to form a handle when used with the tool.

The tubular extension device may be of fixed or variable length and may be of telescopic form.

Adjustable pivot means may be provided on the tubular extension device, proximate the first end portion thereof, whereby an operating position of the tool is adjustable relative thereto.

The tool may have an operating head portion rotatable relative to the hollow housing portion into selected operating positions.

The tubular extension device may comprise metal.

The battery pack may comprise rechargeable or non- rechargeable battery means.

The hand-held battery-powered motor-driven electric tool may comprise trimming apparatus such as for use in gardens and may comprise a cutting head incorporating a motor-driven rotatable cutting edge such as a blade or cutting wire. Such blade or cutting wire may comprise metal or plastics material.

By means of the present invention, a hand-held battery- powered motor-driven electric tool may be provided which is capable of operation at close range without the tubular extension device, or is quickly adapted for long range operation by adding the tubular extension device.

For a better understanding of the present invention and to show more clearly how it may be carried into effect, reference will now be made, by way of example, to the accompanying drawings in which: Figure 1 is a perspective view of an embodiment of a hand-held battery-powered motordriven electric tool in 1 1 - 7 the form of a garden trimmer, arranged without a tubular extension device of the present invention) Figure 2 is a perspective view of the tool of Figure 1 showing a battery pack removed therefrom) Figure 3 is a perspective view of the tool of Figure 1 provided with an embodiment of tubular extension device according to the present invention) Figure 4 is a perspective view of the arrangement of Figure 3, showing the tubular extension device detached from the tool and showing the battery pack removed from the tubular extension device) Figure 5 is a perspective view of the arrangement of Figure 3, illustrating pivotability of the tool on the tubular extension device) and Figure 6 is a perspective view of the arrangement of Figure 3, with a head of the tool rotated, on a housing portion thereof, into a different operating position.

Referring to Figures 1 and 2, a hand-held battery-powered motor-driven electric tool is provided for use as garden trimming apparatus. The tool 2 comprises a handle 4, 1 1 - 8 suitably moulded of plastics material and of generally circular cross-section. A cutting head 8 is rotatably attached to a first end 6 of the handle 4 furthest from a user in use.

The handle 4 comprises a hollow housing portion 10 of elongate tubular form in which an elongate battery pack 12 is provided. The battery pack 12 is removable from the handle 4 and may be non-rechargeable or rechargeable by separate means (not shown).

The removable battery pack 12, as shown in Figure 2, is provided with two battery terminal contacts 14, 16 at opposite side regions of a first end 18 of the battery pack 12, which are positioned to slidingly engage two electrical contacts 20, 22 correspondingly provided within the hollow housing portion 10 of the handle 4. A second end 24 of the battery pack 12, opposite the first end 18, is dimensioned to provide a closure for the hollow housing portion 10 of the handle 4 and act as a rearward end 26 of the handle 4. The battery pack 12 is held in place within the hollow housing portion 10 of the handle 4 by a latch means 28, suitably of spring-loaded form. Provided on either side of the second end 24 of the battery pack 12 is a manually-operated release means 1 1 9 - which releases the latch means 28 to enable the battery pack 12 to be removed.

A switch means 32 is provided on the handle 4 and operable to connect the battery pack 12 to a driving motor 34 of the tool 2, whereby the motor 34 can be energized. The switch means 32 is preferably of safety dual-action type, such that an operating lever 36 thereof is only able to be manually actuated after a safety button 38 has been pressed by a user.

Shielding members 40 are provided on the handle 4 for protecting and supporting a hand and wrist of the user.

The cutting head 8 is provided with a guard 42, which surrounds a cutting blade or wire 44 driven by the motor 34. The cutting blade or wire 44 suitably comprises metal or plastics material.

The tool 2, in the form shown in Figures 1 and 2, is ideally suited for holding by a user close to a surface to be trimmed, such as an edge of a lawn or a shrub. The cutting head 8 can be rotated into a selected operating position at the first end 6 of the handle 4. -

There are applications where it is desirable to be able to operate the tool 2 by a user from a remote location, such as for trimming lawn edges from a standing up position. This is achieved in the present invention, as shown in Figures 3 and 4, by providing a substantially rigid tubular extension device 46 for attachment to the tool 2 and suitably comprising metal or plastics material.

The tubular extension device 46 has a first end portion 48 profiled and dimensioned to substantially correspond to the exterior of the battery pack 12 and adapted to be received in the hollow housing portion 10 of the handle 4 of the tool 2 after removing the battery pack 12 from the hollow housing portion 10. The first end portion 48 of the tubular extension device 46 is provided with two electrical contacts 50, 52. Electrical contact 50 is arranged to slidingly engage one of the electrical contacts 20 (shown in Figure 2) provided in the hollow housing portion 10 of the tool 2, which electrical contact 20 is otherwise engaged by the contact 14 on the battery pack 12 when the battery pack 12 is provided in the hollow housing portion 10 in place of the first end portion 48 of the tubular extension device 46. The electrical contact 52 on the first end portion 48 of the tubular extension device 46 is not however provided in a - 11 position where it can slidingly engage the other electrical contact 22 (shown in Figure 2) provided for use with the battery pack 12 in the hollow housing portion 10. This other electrical contact 22 is connected to the motor 34 through the switch means 32. A third electrical contact 54 (shown in Figure 2) is provided inside the hollow housing portion 10, and arranged for slidingly engaging only the electrical contact 52 on the first end portion 48 of the tubular extension device 46. This electrical contact 54 in the hollow housing portion 10 of the tool 2 is electrically connected directly to the motor 34 such that the switch means 32 in the tool 2 is by-passed when the tubular extension device 46 is in position.

The first end portion 48 of the tubular extension device 46 is releasably secured in the hollow housing portion 10 of the tool 2 by a latch means 56, suitably of spring- loaded form, and substantially the same as the latch means 28 provided on the battery pack 12. Provided on either side of the first end portion 48 of the tubular extension device 46 is a manually-operated release means 58, substantially the same as the release means 30 on the battery pack 12, which releases the latch means 56 to enable the tubular extension device 46 to be removed from the tool 2.

- 12 - The tubular extension device 46 has a second end portion 60, which may be of plastics material, suitably shaped to form a handle for holding by a user. The second end portion 60 of the tubular extension device 46 is provided with a hollow housing portion 62 of substantially the same form as the hollow housing portion 10 of the tool 2 and adapted to demountably receive the battery pack 12 removed from the hollow housing portion 10 of the tool 2 (or an alternative battery pack 12 if so desired). The battery pack 12 is retained in the hollow housing portion 62 at the second end portion 60 of the tubular extension device 46 by its latch means 28 and is releasable therefrom by manual operation of its release means 30.

Two electrical contacts 64, 66 are provided inside the hollow housing portion 62, adapted to be slidingly engaged by the contacts 14, 16 respectively on the battery pack 12, when the battery pack 12 is inserted into the hollow housing portion 62.

Electrical lead wires 68 are provided, passing through the tubular extension device 46, between the first 48 and second 60 end portions thereof and connecting the contacts 50 and 52 at the first end portion 48 with the contacts 64 and 66 at the second end portion 60, by way of a switch means 70 provided at the second end portion 60. The switch means 70 is adapted to control energising of the motor 34 in the tool 2 from the battery pack 12 and is suitably of a safety dual- action type, substantially the same as the switch means 32 on the tool 2 and comprising an operating lever 72 which can only be actuated after pressing a safety button 74.

By means of the present invention, the tool 2 of Figures 1 and 2 can be readily converted from close-up operation by a user to long range operation by the user as shown in Figures 3 and 4, by simply transferring the battery pack 12 from the hollow housing portion 10 of the tool 2 into the corresponding hollow housing portion 62 of the second end portion 60 of the tubular extension device 46 and inserting the first end portion 48 of the tubular extension device 46 into the vacated hollow housing portion 10 of the tool 2. The switch means 32 on the tool 2 is then automatically by-passed and control of energising of the motor 34 from the battery pack 12 is effected by the switch means 70 at the second end portion of the tubular extension device 46.

The tubular extension device 46 may be of fixed length, or may be of variable length such as being provided of telescopic form.

- 14 - Adjustable pivot means 76 may be provided on the tubular extension device 46, proximate the first end portion 48 thereof, such that an angle 78 of the tubular extension device 46 may be adjusted relative to the tool 2, as shown in Figure 5.

As previously described with reference to Figures 1 and 2 and as illustrated in Figure 6, the cutting head 8 of the tool 2 may be rotatably attached to the handle 4 of the tool 2, as indicated by arrows 80 in Figure 6, such that a desired operating position of the cutting head can be selected as required.

Although the present invention has been particularly exemplified by way of a tool 2 in the form of garden trimming apparatus, the invention is not limited to such apparatus and the tubular extension device may be applied in general to hand-held battery-powered motor-driven electric tools. -

Claims

1. A substantially rigid tubular extension device for a hand-held batterypowered motor-driven electric tool, the tool comprising a hollow housing portion adapted to demountably receive a battery pack, the tubular extension device comprising: a first end portion adapted to be demountably received in the hollow housing portion of the tool in place of the battery pack; a second end portion adapted to demountably receive the battery pack therein; and electrical connection means between the first and second end portions, adapted for electrical connection of the battery pack to a motor of the tool.

2. A device as claimed in claim 1, wherein the battery pack and the first end portion of the tubular extension device each have a substantially similar external configuration.

3. A device as claimed in claim 1 or 2, wherein first manually-operable latch means is provided, adapted to cooperate between the hollow housing portion of the tool and either the battery pack or the first end portion of the tubular extension device, for releasably securing the battery pack or the first end portion of the tubular - 16 extension device in the hollow housing portion of the tool.

4. A device as claimed in claim 3, wherein the latch means is of springloaded form.

5. A device as claimed in any preceding claim and including second manually-operable latch means is provided, adapted to cooperate between the second end portion of the tubular extension device and the battery pack, for releasably securing the battery pack in the second end portion of the tubular extension device.

6. A device as claimed in claim 5, wherein the second latch means is of spring-loaded form.

7. A device as claimed in claim 5 or 6 when dependent on claim 3 or 4, wherein the first and second latch means are both of substantially the same form.

8. A device as claimed in any preceding claim, wherein the electrical connection means comprises electrical leads extending through the tubular extension device between the first and second end portions thereof. r I 17

9. A device as claimed in any preceding claim, wherein switch means is provided at the second end portion of the tubular extension device and adapted to control supply of electric power from the battery pack to the tool.

10. A device as claimed in claim 9, wherein the switch means is of safety dual-action type and incorporates a button which is required to be pressed before an operating lever is able to be actuated.

11. A device as claimed in any preceding claim, wherein first and second electrical contact means is provided electrically connected to the electrical connection means at first and second end portions respectively of the tubular extension device, third electrical contact means being provided in the hollow housing portion of the tool, and fourth electrical contact means being provided on the battery pack, the third electrical contact means being adapted to be slidingly engaged by either the first or the fourth electrical contact means, the second electrical contact means being adapted to be slidingly electrically engaged by the fourth electrical contact means. - 18

12. A device as claimed in claim 11, wherein the first, second and fourth electrical contact means each comprise two electrical contacts.

13. A device as claimed in claim 11 or 12, wherein the third electrical contact means comprises three electrical contacts, a first one of which is engageable by one of the contacts of either the first or the fourth contact means, a second one of which is engageable by the other contact of the fourth contact means such that the tool is electrically supplied from the battery pack through a further switch means provided on the tool, when the battery pack is located in the hollow housing portion, and a third one of which is engageable by the other contact of the first contact means such that the further switch means on the tool is by-passed, when the first end portion of the tubular extension device is located in the hollow housing portion.

14. A device as claimed in claim 13, wherein the further switch means is of safety dual-action type and incorporates a button which is required to be pressed before an operating lever is able to be actuated.

15. A device as claimed in any preceding claim, wherein the hollow housing portion of the tool comprises a handle - 19 portion for the tool when used without the tubular extension device.

16. A device as claimed in any preceding claim, wherein the second end portion of the tubular extension device is adapted to form a handle when used with the tool.

17. A device as claimed in any preceding claim, wherein the tubular extension device is of fixed length.

18. A device as claimed in any one of claims 1 to 16, wherein the tubular extension device is of variable length.

19. A device as claimed in claim 18, wherein the tubular extension device is of telescopic form.

20. A device as claimed in any preceding claim, wherein adjustable pivot means is provided on the tubular extension device, proximate the first end portion thereof, whereby an operating position of the tool is adjustable relative thereto.

21. A substantially rigid tubular extension device substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.