COMBUSTION ENGINES

The present invention relates to a device for inhibiting the theft of internal combustion engines, for instance generators, outboard engines, lawn mower engines, chain-saw engines, and like engines of the kind in which one end of a pull-cord is wound firmly around a rotatable magnet on the engine, or motor, and the other end of the cord is attached to a handle, wherein a pull on the cord causes the magnet to rotate and therewith generate an ignition spark in a spark plug or plugs.

Most devices using pull start mechanisms are by nature small, portable and of high value. Because they do not normally incorporate security or locking mechanisms they are also prone both to theft and to misuse by unauthorised persons who may have free access to the device.

The objects of this invention are two-fold. Firstly, to provide a means by which to deter the theft of such devices by rendering them extremely difficult for any non- keyholder to use without severely damaging the starting mechanism and thus also severely reducing the functionality and the resale value of the device. Secondly, this invention allows the owner/keyholder of such a device to restrict its use to him/herself or to any appointee who may be granted use of the key.

For example, outboard motors are often theft-attractive objects and are often mounted on the boat solely by means of a manually manipulatable attachment. This applies in particular to engines of up to 30 HP. It is a simple matter to detach engines of this kind from the boat to which they are fitted and install the engine on another boat. All that is required is to connect the engine fuel feed to a fuel tank.

The object of this invention is not only to inhibit the actual theft, but also to cause such damage to a stolen generator or engine as to make it difficult to sell, should the theft-inhibiting device be successfully overcome. The invention provides an engine or generator provided with such a device and also devices that can be retrofitted into existing engines or generators. United States Patent 5738058 describes a device for inhibiting the theft of pull-start internal combustion engines and the present invention provides an improvement to such a device. United States Patent 5738058 provides a lock plug that is inserted through an opening in the grip part of the pull cord that is used to start the engine. Rotation of the lock plug to the lock position prevents pulling of the handgrip part and thus prevents the starting of the engine. In the device of United States Patent 5738058 the handgrip part stands proud from the motor and can be handled and manipulated even when in the locked position. Furthermore, the locked handgrip part can be an impediment or a safety hazard for the user of the motor. The present invention overcomes these problems.

The present invention therefore provides a pull start engine comprising an engine or generator and provided with a pull start mechanism comprising a cord and a handle or grip pull wherein a retaining means is provided with a cavity for receipt of the handle or grip pull whereby the grip pull can be locked within the cavity to deny access to the handle or grip pull.

The invention further provides a pull start mechanism comprising a handle or grip pull attachable to a cord together with a retaining means provided with a cavity for receipt of the handle or grip wherein the handle or grip pull can be locked within the cavity and the plate can be secured to an engine or generator.

The retaining means may be part of the housing of the engine or generator or may be a plate which may be secured to the engine or generator. The cavity in the retaining means is formed with a hole which allows the handle or grip pull to be attached to a pull cord that when pulled, starts the motor.

The handle or grip pull is preferably provided with a locking mechanism such as that described in United States Patent 5738058. However, in addition according to this invention the handle or grip pull may be placed or forced into the cavity of the engine housing or the plate and locked in position inside the cavity. In a preferred embodiment the handle compresses a spring as it is pressed into the cavity and is locked with the spring in the compressed position. When the handle or grip pull is unlocked it is ejected from the cavity by the decompression of the spring to provide the handle or grip pull ready for use. In the embodiment employing the plate containing the cavity, the plate may be secured to the engine or generator by bolting thereto or by means of a structural adhesive. Any suitable locking mechanism may be used to secure the grip pull or handle in the cavity. For example a key operated locking mechanism such as that described in United States Patent 5738058 may be used. Alternatively, an electronic locking device such as a fob operated lock may be used. The present invention is illustrated by reference to the accompanying drawings in which Figure 1 is an exploded view of the system of the present invention in which the cavity is in the engine housing and the lock is in the closed position.

Figure 2 shows the system of Figure 1 in the lock open position.

Figure 3 is a top elevation of the system of Figure 1 showing the handle grip pull locked into and flush with the housing of the motor.

Figures 4 to 7 show the retrofit embodiment of the invention.

Figure 1 shows part of the housing of the motor (1 ) provided with a cavity (2). The cavity is of a size that it can receive the handle or grip pull (3) of the starter system. The handle is provided with a lock cylinder (4) and a locking pin (5) which can be activated to lock or unlock the handle within the cavity by means of the key (6). The handle is provided with means (7) for connection to the pull cord (8). The cavity (2) is provided with a spring (9) retained within spring retaining means (10).

Accordingly, the handle or pull cord can be pressed into the cavity such that the means (7) passes through the housing and can be connected to the pull cord (8). As the handle is pressed into the cavity the spring (9) is compressed as shown in Figure 1 and the handle can be locked whilst in the cavity (2) to provide a surface that is flush with the housing as illustrated in Figure 3. When the lock is unlocked the spring will decompress to the position shown in Figure 2 urging the handle or grip pull (3) out from cavity (2) into a position ready for operation to start the engine. Once the engine is no longer in use the handle or grip pull may be put back into the cavity and locked in the secure position. Figure 4 shows a retrofit system that can be secured to an engine or generator. The system comprises a handle or grip pull (11 ) ready for attachment to a starter cord (12) (as shown in Figure 5). The handle or grip pull (11 ) fits within the cavity (13) formed in a plate (14). The plate is provided with holes (15) and (16) which can be used to bolt the plate to the engine or generator. The handle is also provided with an insert (17) for the locking mechanism. Figure 5 is a side view showing the grip or hand pull of Figure 1 attached to the start cord (12) and it also shows the slot (18) which can receive a locking pin to lock the handle or grip pull within the cavity of the plate.

Figure 6 shows an embodiment such as that shown in Figure 5 but without the handle or grip pull and shows the spring plates (19) and (20) which can eject the handle or grip pull from the cavity when the device is unlocked. Figure 7 is a top view showing the handle or grip pull locked within the cavity in the plate.