AU694908B1 - Anti-theft device - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

S

0t

S

Name of Applicant: Actual Inventor: Address for Service: Andrew George GATHERGOOD As above CULLEN CO., Patent Trade Mark Attorneys, 240 Queen Street, Brisbane, Qld. 4000, Australia.

Invention Title: ANTI-THEFT DEVICE Details of Associated Provisional Application: Patent Application No. 41863/97 filed on 17 October 1997 and which has been converted to a provisional application on 1 April 1998 The following 'tatement is a full description of this invention, including the best method of performing it known to me: ANTI-THEFT DEVICE TECI-HNICAL FIELD This invention relates to an anti-theft devices for combustion engine vehicles. More specifically, this invention relates to a locking device for mounting over the end of an exhaust pipe of a vehicle.

The theft of motor vehicles is a major problem in many cities around the world. Often cars are stolen by "hotwiring" the ignition thereby overcoming the key operated starters of many motor vehicles. It is quite apparent that having key operated ignition is not particular efficacious in resisting vehicle theft. Clearly, a more effective and economic means for resisting theft of motor vehicles is highly desirable.

S•BACKGROUND ART Several devices for resisting theft of motor vehicles have been proposed, e.g. alarms, steering locks and immobilizers. However, all of these 15 devices have short-comings. For example, immobilizers and audio alarms are very sophisticated and expensive. Further, steering locks can easily be broken.

Another technique of immobilizing vehicles for security purposes is to fit a locked cap to the end of a vehicle exhaust. The locked cap seals the end of an exhaust pipe and immobilizes the vehicle.

U.S. patent 4,683,735 discloses a technique such as described.

U.S. patent 4,683,735 discloses a lockable closure for the exhaust pipe of an internal combustion engine. The exhaust pipe closure comprises a lockable cap adapted to fit onto an extender tube (or the exhaust pipe, which has been suitably modified). The cap includes a pair of jaws which may be urged outwardly by the operation of a plunger to engage a locating formation in either the exhaust pipe or the extender tube.

The device described requires a key to lock and to unlock the closure. I consider that the use of a key to lock the closure onto an exhaust is a distinct disadvantage.

An object of the present invention is to provide a locking device which enables keyless attachment of the device to the free end of an exhaust pipe.

Further objects and advantages of the present invention will become apparent from the ensuing description.

DISCLOSURE OF THE INVENTION According to the present invention, there is provided a locking device for attachment to a combustion engine exhaust pipe of a vehicle the locking device comprising a cap, a lock body which mounts a mechanical lock release, an actuable ratchet latch cooperative with said lock release and having one or more biased keys extending from the periphery thereof, the arrangement being such that the locking device can be engaged with an internal channel formei at the free end of an exhaust pipe in a snap fitting arrangement as the lock body passes into the free end of the exhaust pipe, said one or more biased S".i keys retracting and then expanding to secure the locking device with respect to the internal channel of the exhaust pipe.

The said one or more biased keys are provided with an outer facing surface which is outwardly and rearwardly divergent and which provides an inwardly directed shoulder which when the latch body is engaged with the free S* end of an exhaust pipe cooperates with the internal channel of the exhaust pipe and prevents removal of locking device from the exhaust pipe until the lock release is actuated.

Actuation of the lock release results in complete withdrawal of the said one or more biased keys from the internal channel of the exhaust pipe.

S° The locking device can include internal sealing means positioned in the inner face of the cap.

The sealing means can be a resilient membane.

The said one or more biased keys can be permanently biased into an expanded position by a spring.

The lor body can comprise a barrel securing a key lock mechanism said key lock mechanism having extending member for engaging with the ratchet latch in such a manner that when a key is inserted into the key lock and turned the extending member engages with the said one or more biased keys of the ratchet latch and withdraws same.

The said at least one or more biased keys can be housed within an internal channel within the barrel and comprise two separate spring loaded oppositely biased keys which exte' .d from the wall of the barrel in opposite directions.

Each of the spring loaded keys is provided with socket engageable with the extending member of the key lock mechanism.

According to a further aspect of the invention, there is provided a locking device as aforesaid in combination with a swaged fitting for the fitment to the free end of an exhaust pipe.

The fitting can be provided with an end section which provides an io internal channel.

The invention also provides a method of immobilizing a vehicle S, comprising the fitting of a locking device as aforesaid to the free end of an exhaust pipe which has an internal channel fashioned into its end BRIEF DESCRIPTION OF THE DRAWINGS A locking device in accordance with this invention may manifest itself in a variety of forms. It will be convenient to hereinafter describe in detail two preferred embodiments of the invention. It is to be clearly understood however, that the specific nature of this description does not supercede the generality of the preceding statement. In the drawings: ,o 20 Figure 1 is a side view of a fitted locking device in accordance with the invention; Figures 2, 2a and 2b are front, side and rear views of the pipe of the device of Figure 1; Figure 3 is a sectional side view of the pipe of Figure 2; Figures 4, 4a and 4b are front, side and rear views of the locking device of Figure 1; Figure 5 is a sectional view of the locking device of Figure 1; Figure 6 is a sectional side view of the assembled locking device inserted into the pipe; Figure 7 is a sectional front view of the locking device being inserted in the pipe; Figure 8 is a side view of an anti-theft device in accordance with a second embodiment of the invention; Figure 9 is a view of the cap and lock release taken at IX:IX of Figure 6; Figure 9a is a sectional view taken at 9a:9a of Figure 9; and Figure 10 is a view taken at X:X of Figure 6.

Figures 1 to 7 illustrate a first embodiment of an anti-theft device indicated generally by a reference numeral 1.

With respect to the drawings and in particular Figures 1 to 7, a locking device according to the present invention generally indicated by arrow 1 combines with a modified end 2 of a pipe 3. In the manner illustrated, the locking device comi"rises a cap 4 and a lock body generally indicated by arrow 5. The lock body 5 mounts a mechanical lock release 6 and comprises a barrel 7 from which extends an actuable ratchet latch which has at least one (in the illustrated instance two) biased keys 8 extending from the sidewalls of the barrel 7. The locking device can be engaged with an internal channel 9 formed in the free end of end 2 in a snap-fitting arrangement as the lock body 5 passes onto the end 2, the keys 8 retracting and then expanding once they have registered in the channel 9. The keys 8 are provided with an outer facing surface 10 which is divergent from the distal end of the body 5 and have an inwardly directed shoulder 11 which when the body 5 is engaged with a pipe end (see Figure 6) co-operates with the channel 9 and prevents removal of the locking device from the end 2 until the lock release 6 is actuated. Actuation of the lock release can be made with the use of a tab key 12.

The internal channel 9 can be formed at the end of modified end 2 by swagging as illustrated and the end 2 securely fixed over the end of pipe 3.

There is also the possibility of a channel being formed in situ or for new vehicle manufacturers to shape the ends of vehicle exhausts to suit the locking device.

The tab key 12 is only used to release the locking device from the exhaust and because the biased keys 8 are configured as described, it is only necessary to apply slight pressure to the cap 2 as the keys pass mouth 13 of end 2 to secure the device on an exhaust pipe.

The barrel 7 and lock release 6 are combined and in the illustrated -a example, the lock release 6 is embodied in a tubular sleeve 14 fixed to the cap 4.

The lock release is provided with a cylindrical body 15 having engagement means generally indicated by arrow 16 in the form of two lugs 17 extending from the end of the body. The barrel 7 in which accommodates the lock release 6 is tubular and provides an internal channel 18 in which keys 8 are located. Each key 8 is provided with a socket 19 and is slidable in the channel 18 and is constantly under the bias of springs 20. The lugs 17 engage in the sockets 19 (see Figure 10) and when the tab key 12 is rotated, the lugs 17 make contact with walls of the sockets 19 and the keys 8 withdraw against the bias of the springs 19. The locking device can then be removed from the exhaust pipe as the keys 8 are no longer in register with the internal channel 9.

S• It is preferable for the locking device to seal off the end of the exhaust pipe and in this respect, an arrangement can be provided whereby a resilient membrane or membranes 21 can be provided on the inner surfaces of the cap 4. The resilience of the membranes may be assisted by the placement of a spacer 22 between two layers of membrane.

Sa. ~Pipe 2 can be made of rust proof material e.g. stainless steeel and may be chromed. The cap 4 may be provided with a luminous portion or portions so that it is readily identifiable as a security device and locatable in the darkness.

If an unauthorized person, e.g. a car thief tries to steal the car while the locking cap is mounted over the exhaust pipe, the engine simply will not run because the exhaust gases cannot escape. When the owner or authoriLd user of the vehicle returns to their car, they can remove the cap by simply inserting the key and rotating the key and then pulling off the cap.

Figure 8 illustrates a second embodiment of the invention. The invention is similar in structure and function to the first embodiment and thus the same reference numerals are used to refer to the same components.

The main difference with this embodiment is that the end of the actual exhaust pipe is crimped, rather than having a crimped pipe sectionwhich is welded to the pipe. Thus, the radially inwardly extending locking formation in this embodiment is actually integral with the exhaust pipe and formed in the exhaust pipe at the time of manufacture.

LI*ls~ Y An advantage of this invention is that a simple and inexpensive, yet extremely efficacious anti-theft device is provided. Further, crimping the end of a pipe is a relatively straightforward operation which can be done to any pipe.

Yet further, a locking cap suitable for locking to the end of the exhaust pipe can easily be obtained at reasonable cost.

It is to be understood that all modifications and variations to the above device which would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of the invention.

5005 S *#e a~ ~RP-9

Claims (14)

1. A locking device for attachment to a combustion engine exhaust pipe of a vehicle the locking device comprising a cap, a lock body which mounts a mechanical lock release, an actuable ratchet latch cooperative with said lock release and having one or more biased keys extending from the periphery thereof, the arrangement being such that the locking device can be engaged with an internal channel formed at the free end of an exhaust pipe in a snap fitting arrangement as te lock body passes into the free end of the exhaust pipe, said one or more biased keys retracting and then expanding to secure the locking device with respect to the internal channel of the exhaust pipe.

2. A locking device as claimed in claim 1 wherein the said one or more biased keys are provided with an outer facing surface which is divergent S from the distal end of the latch body and which provides an inwardly directed shoulder which when the latch body is engaged with the free end of an exhaust pipe cooperates with the internal channel of the exhaust pipe and prevents removal of locking device from the exhaust pipe until the lock release is actuated.

A locking device as claimed in claim 2, wherein actuation of the o lock release results in complete withdrawal of the said one or more biased keys from the internal channel of the exhaust pipe.

4. A locking device as claimed in any one of claims 1 to 3 including a sealing means positioned in the inner face of the cap and extending abou t the periphery of the lock body.

A locking device as claimed in claim 4, wherein the sealing means is a resilient membane.

6. A locking device as claimed in any one of claims 1 to 5 wherein the said one or more biased keys are permanently biased into an expanded position by a spring.

7. A locking device as claimed in any one of claims 1 to 6 wherein the lock body comprises a shroud securing a key lock mechanism which provides an extending member for engaging with the ratchet latch in such a manner that when a key is inserted into the key lock and turned the extending member engages with the said one or more biased keys of the ratchet latch and withdraws same.

8. A locking device as claimed in claim 7, wherein the said at least one biased keys are housed within a barrel secured to the cap the barrel providing an internal channel accommodating two separate spring loaded oppositely biased keys and opposed openings through which the spring loaded keys are extensible.

9. A locking device as claimed in claim 8, wherein each of the spring loaded keys are provided with sockets engageable with the extending member.

A locking device as claimed in any one of claims 1 to 7 in combination with a swaged fitting for the fitment to the free end of an exhaust pipe.

11. The combination of claim 8 wherein the fitting is provided with a end section which provides an internal channel.

12. A method of immobilizing a vehicle comprising the fitting of a locking device as claimed in any one of claims 1 to 8 to the free end of an exhaust pipe which has an internal channel fashioned into its end.

13. A locking device substantially as herein described with reference to the accompanying drawings.

14. The combination of a locking device and an exhaust fitting 20 substantially as herein described with reference to the accompanying drawings. A method of immobilizing a vehicle substantially as herein described with reference to the accompanying drawings. DATED this 2 d day of April 1998 Andrew George GATHERGOOD By his Patent Attorneys CULLEN CO. I-, ABSTRACT A locking device for immobilising vehicles which comprises a cap and lock body for fitment to the free end of a vehicle exhaust pipe. The locking device is constructed to facilitate keyless fitting and can be released from the exhaust pipe by the use of a key. to I to 4* 0 a