TECHNICAL FIELD

This invention relates to a chainsaw attachment.

BACKGROUND ART

Chainsaws are popular cutting devices. For example, farmers, carvers, logging contractors and others regularly using such devices for cutting timber, wooden posts, tree limbs and so forth.

Unfortunately there exists several problems related to the use of chainsaws.

One problem is related to the limited number of substances a conventional chainsaw may be used to cut. Chainsaws are most effective cutting wood and similar materials, but have proved to be inefficient and difficult to use when cutting wire rope, steel and other hard materials. A device whereby a chainsaw may be modified to cut these materials would be a significant advantage over existing chainsaws.

Another problem with chainsaws is lack of versatility. In situations where chainsaws are used, there are tasks other that cutting to be performed which require extra machinery. Examples may include carving, polishing, pumping, drilling, grinding or sanding of wood. These tasks can only be performed at the present time with separate carving, polishing or sanding units which adds to the expense and time in carrying out these operations. A unit which can cut like a chainsaw but also polish, sand as well as perform other tasks would be a significant advantage.

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It is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice.

Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.

DISCLOSURE OF INVENTION

According to one aspect of the present invention there is provided an attachment for a chainsaw motor comprising a bar, a flexible linkage, a drive mechanism and attachment device for an implement, wherein the flexible linkage is capable of interacting with the drive device of the chainsaw motor and interacting with the drive mechanism of the attachment, the arrangement and construction being such that an implement attached to the attachment device can be driven by the drive mechanism which in turn is driven by flexible linkage interacting with the chainsaw drive device.

The flexible linkage will now be referred to as a chain, although it should be appreciated that other flexible linkages, for example, belts may be used.

In preferred embodiments of the present invention the bar may substantially resemble an existing chainsaw bar, although modifications of the bar near the drive mechanism of the attachment may also be made.

In some embodiments the bar may be insertable into the chainsaw in the same way a usual chainsaw bar is, and is also removable in the same way as a usual chainsaw bar.

In some embodiments of the present invention the bar may be enclosed by the chain, and may guide the movement of the chain. In these

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embodiments the periphery of the bar may be grooved or slotted, these grooves or slots providing a channel for guiding the chain. Other embodiments of the bar may include rods extending from the chainsaw body to the drive mechanism, or to various other supporting structures of the implement, as well as any other similar design.

In preferred embodiments of the present invention the chain may resemble a standard chainsaw chain. In some embodiments the usual cutting teeth on the chain may not be present. Thus the chain may form an interlinking structure, similar to a bicycle chain, whereby apertures can be included in the chain for attachment to toothed wheels or cogs.

Other forms of chains are also envisaged, but it is expected that the greater the similarity between the chain and a standard chainsaw chain, the easier the installation process of the chainsaw attachment will be.

In preferred embodiments of the present invention there is provided a safety guard positioned around the chain.

In preferred embodiments of the present invention the drive mechanism may consist of a toothed sprocket. This sprocket may resemble existing chainsaw sprockets, although it also may be modified for the purpose of driving the implement. In embodiments whereby the sprocket is toothed and the chain includes apertures, the teeth are preferably designed to be insertable into the apertures, thus providing a firm link between the chain and drive mechanism.

The sprocket may in some versions of this invention fit into the bar itself.

In some embodiments of the present invention the drive mechanism may consist of more than one sprocket, or may be a geared mechanism. Other forms of drive mechanisms, which may include levers, pulleys, or pistons

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may also be used, as may any device which interacts with the chain and attachment device for a implement in such a way as to result in the driving of the implement.

In preferred embodiments of the present invention there may be included an attachment device including a front and backing plate, and fastening device or devices. In these embodiments the implement may be mounted between the front and backing plate, and secured in place by use of the fastening device.

The fastening device may consist of a bolt and washer, or many bolts and washers, or any other device with a similar function.

The backing plate may be secured to the drive sprocket by further fastening devices, which may or may not also be used to attach the implement to the attachment device.

In further embodiments of the present invention the attachment device may include fixtures welded onto the sprocket, such fixtures being able to support the implement in any number of ways.

Other forms of attachment device may include a lock and key hole system for inserting the implement into the attachment device and locking it in place by subsequent rotation or translation of the implement. Other forms of attachment, such as gluing or welding may be employed.

In preferred embodiments of the present invention the implement may be a cutting apparatus, preferably for cutting materials that existing chainsaws do not cut well. In some embodiments the cutting implement may be a cutting disc, which is secured to the drive mechanism by the attachment device, and rotates at high speed as the drive mechanism is driven by the chain. The cutting implement may have a cutting blade on

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its circumference, or may include the use of teeth, serrated edges, or other cutting devices.

In further preferred embodiments of the present invention the implement may be a tool performing any one of a number of functions. In some embodiments the implement may be a carving tool. This may consist of a hard surface, which may be driven by either an oscillatory or vibratory motion derived from the action of the chainsaw motor. Other forms of motion are also envisaged.

In further embodiments of the present invention the implement may be a sanding apparatus. This may consist of a surface of any shape, although commonly flat, covered in a roughened surface. The roughened surface may include bumps or protuberances of any variety. Again the implement may be driven in a vibratory or oscillatory motion, which when put in contact with a second surface may lead to sanding of the second surface.

Further implements, such as implements for polishing, are also envisaged.

Chainsaws by their nature can be unwieldy and difficult to balance. This awkwardness is potentially enhanced by the addition of attachments. Thus in preferred embodiments there is provided a support device which can assist in providing stability. The support device may come in a variety of forms and in some embodiments may be a bar which allows the device to sit easily on a surface.

In preferred embodiments of the present invention the chain may interact with the drive device of the chainsaw motor and the drive mechanism of the attachment. Such an interaction may be carried out by the teeth and aperture attachment device already described or some similar device,

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Preferably the interaction may translate the rotational drive of the chainsaw motor to a substantially rotary motion of both the chainsaw chain and drive mechanism of the attachment. The rotary motion of the drive mechanism may then result in a similar motion of the implement. Other forms of interaction and motion are also envisaged.

In one embodiment of the present invention there is provided a unit incorporating a chainsaw motor and an attachment device as previously described.

According to one aspect of the present invention there is provided a method for driving an implement characterised by the steps of

a) attaching a bar, a flexible linkage, a drive mechanism and an attachment device for the implement to the drive device of a chainsaw motor so that the flexible linkage is capable of interacting with the chainsaw motor and the drive mechanism of the implement, and

b) driving the implement attached to the attachment device in such a way that it is driven by the drive mechanism which in turn is driven by the flexible linkage interacting with the chainsaw device.

In preferred embodiments of the present invention the method for driving the implement may include the steps of removing a standard chainsaw bar and chain, and replacing them with a modified chainsaw bar and chain.

In some embodiments the bar, chain, drive mechanism, attachment device and implement may all form a single unit, while in further embodiments some assembly of the units may be needed.

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BRIEF DESCRIPTION OF DRAWINGS

Further aspects of the present invention will become apparent from the ensuing description which is given by way of example only and with reference to the accompanying drawings in which:

Figure 1: is a side on view of a chainsaw and chainsaw attachment in accordance with a preferred embodiment of the present invention, and

Figure 2: is a top view of an attachment device in accordance with a preferred embodiment of the present invention

Figure 3: illustrates and alternative attachment device

BEST MODES FOR CARRYING OUT THE INVENTION

With respect to Figure 1 there is illustrated a chainsaw and chainsaw attachment, generally indicated by arrow 1.

In this embodiment a drive sprocket 5, bar 2 and chain 3 is included. The drive sprocket 5 is attached to the bar 2 and driven by the chain 3. In operation rapid rotary motion of the chain 3 leads to a similar rapid rotary motion of the drive sprocket 5.

In some embodiments the sprocket 5 may be positioned in line with the bar 2 as illustrated in Figure 3.

A chainsaw body 4 houses the device by which the chain 3 is driven.

The drive sprocket 5 is also connected via an attachment device (shown in Figure 2) to the implement 6 hereinafter referred to as a cutting disc. This cutting disc 6 may be attached to various other devices such as a guard 7 or

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handle 8. The guard 7 helps shelter the chainsaw user from chips or sparks resulting from the cutting operation as well as inadvertent contact with the cutting surface. The handle 8 provides an extra device of supporting and lifting the implement 6.

There is also provided a support bar 20 which enables the chainsaw 1 to sit easily on a surface.

A safety guard (not shown) may cover the chain 3.

With respect to Figure 2 there is illustrated a top view of the attachment device, generally indicated by arrow 9 for the cutting disc 6.

The attachment device 9 includes a mounting plate 10 for the drive sprocket shaft (not shown), which is secured to the chainsaw bar 2. Such a mounting plate 10 and further supports 15 give the drive sprocket 5 strength and support.

Rotary motion of the drive sprocket 5 is translated to the disc 6. The disc 6 is mounted between a backing plate 11 and front plate 12, and held in position by a washer 13 and fastening bolt 14. The front plate 12 and backing plate 11 provide support for the disc 6, and minimise the effect of vibration caused by the contact of disc 6 with other surfaces.

Figure 3 illustrates an alternative embodiment 9a of the present invention. In this embodiment the drive sprocket 5a is aligned with the bar 2a. A bearing housing 15 is situated between the sprocket 5a and the backing plate 11.

Aspects of the present invention have been described by way of example only and it should be appreciated that modifications and additions may be made thereto without departing from the scope of the appended claims.

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