MECHANICAL THEFT PREVENTION DEVICE FOR VEHICLES

Abstract: A mechanical theft prevention device for vehicles comprising a cylinder-type lock (22) having a valve (10) secured to the extended lock shaft (13) of the lock and rotatable by rotation of the lock shaft (13) by means of a key (27). The fuel supply line (33) to the engine of the vehicle is connected to the valve (10) and, when the valve is turned from an operative position, a valve member (17) movable in the valve engages by gravity a seat and interrupts the fuel supply.

Description: MECHANICAL THEFT PREVENTION DEVICE " FOR VEHICLES This invention relates to a mechanical theft preven¬ tion device for vehicles which is adapted upon activation to make the vehicle temporarily ndrivable by throttling of the fuel supply to the engine. A great many theft prevention devices have become known, for instance mechanical or electrical devices for locking the steering column or the range selector shaft. There .have also been suggested control systems, based on electronics, which, however, suffer from* the disadvantage of being very simple to bypass by "jumping". Mechanical fuel throttling systems have become known for example from U.S. patent 3,855,828 and Swedish patent 85,976, which, however, are inadvantageous because they cannot be made fully tight, which implies a great risk of fires. The object of the present invention is to provide an entirely novel theft prevention device which is simple, inexpensive and readily mountable. This object is realized in that a cylinder-type lock has an extended lock shaft on which there is fastened a valve connected in the fuel supply line,- and that the valve has a movable valve member which upon rotation of the lock shaft and thus of the valve is movable into and out of engagement with a seat and which when engaging the seat interrupts the fuel supply to the engine. An advantageous embodiment of " the invention is characterized in that the lock and the valve in order to be inaccessible to unauthorized persons are enclosed in a casing, the lock being fixed in one wall of the casing by means of a nut disposed inside the casing, and that a contact connected into the electrical net- work of the vehicle is disposed o.n the outer side of said wall and operable by means of the key serving to operate tike. OMPI the lock, such that the .current supply to at least one o the electrical means of the vehicle is interruptible at the same time as the fuel supply is interrupted. A lock of this kind cannot be bypassed and one cann either reach the valve for direct actuation thereof. The lock with the valve is further readily sealed and there is no risk that the fuel supply will be interrupted during driving. An embodiment of the invention will be described in greater detail below with reference to the accompanying drawings in which: Fig. 1 shows a device according to the invention with a valve in operating position, while Fig. 2 shows the valve in latched position, and Fig. 3 shows the connection of fuel supply lines to the valve. In Fig. 1 a cylinder lock 22 is fixed by means of a nut 23 in a metal sheet so located as to be readily ac¬ cessible*from -the driver's seat in the vehicle. The metal sheet 24 may be a metal sheet being part of the automo¬ bile, or a metal sheet especially welded to the automo¬ bile for the contemplated purpose. The lock 22 has an extended lock shaft 13 which is rotatable in the conven¬ tional manner by means of a .key 27. A valve 10 is fixed to the lock shaft 13 by means of a stop screw 14. The valve 10 has an inlet 11 and an outlet 12 by means of which the valve is connectible in the fuel supply line leading to the engine. A hollow space 15 is arranged in ' the valve 10 and at one end the space has been given an arcuate shape to form a valve seat 16 surrounding the outlet 12. At the opposite end the space 15 has a widened threaded portion into which a threaded plug can be screwed for closing the space 15. A valve member 17 in the form of a ball having the same radius as the arcuate seat 16 is disposed in the hollow space 15, Assuming that the valve 10 is connected in- the fuel supply line such that fuel enters through the inlet 11, the fuel in the Fig. 1 position of the valve 10 can un- ( O W impededly escape through the outlet 12 via the hollow space 15 and the automobile can thus be driven. If, however, the key 27 of the lock 22 is turned 180 the lock shaft 13 is also turned so that the valve 10 takes the Fig. 2 position in which the valve member 17 by gravity has fallen into engagement with its seat 16,. The fuel entering through the inlet cannot now escape through the outlet 12 and the fuel supply to the engine is effec¬ tively interrupted. To prevent unauthorized access to the lock 22 and the valve 10 said parts are enclosed in a tight casing 21. The casing also serves to hermetically enclose the valve 10 so that no inflammable fuel vapours can escape. The fuel lines connected to the inlet and the outlet are therefore tightly fastened in the walls of the casing 21. To further improve the tightness of the valve 10 the ^plug 19 closing the hollow space 15 of the valve is preferably connected to the valve body proper by soldering. By the above-mentioned enclosure of the parts 22 and 10 a contact 25 can be disposed on the outer side of the metal sheet 24. This contact is also operated by the key 27 of the lock 22, and the conventional cables for the ignition key of a vehicle can be connected to * the contact so that the lock 22 can be mounted instead of the conven- tional lock of the vehicle. One can of course also retain the conventional lock of the vehicle and have the lock 22 as an additional lock, in which case the contact 25 can be omitted or only used to control some of the essential electrical functions of the vehicle. Preferably, a lamp 28 is disposed above the keyhole of the lock 22 to facil¬ itate introduction of the key 27 into the lock in dark¬ ness. Fig. 3 shows the valve in operative position with the fuel supply line 33 arranged in a loop about it. The line 33 is severed and one part is connected to the inlet 11 of the valve 10 by a screw connection 30, while the other part is connected to the outlet 12 of the valve 10 by a screw connection 29. These screw connections also are soldered to the valve to attain a complete sealing The line 33 is of metal such that it can readily be se in the entrance openings to the housing 21, for instan by soldering, and as the line is arranged in the loop illustrated the valve 10 can be turned unimpededly in the manner described. The winding direction of the lin 33 is so selected that the winding is slightly contrac when the valve 10 is turned from open to closed positi Rubber plates 34, 35 are preferably fastened to the in surface of the casing 21 in order that the loop of the line shall not slide against said surface.

Claims: CLAIMS 1. A mechanical theft prevention device for vehicles which is -adapted upon actuation to..make the vehicle tem¬ porarily undrivable by throttling of .the fuel supply to the engine, c h a r a c t e r i z e d in that a cylinder- type lock (22) has an extended lock shaft (13) on which there is fastened a valve (10) connected in.the -fuel supply line, and that the valve (10) has a movable valve member (17) which upon rotation of the lock shaft (13) and thus of the valve (10.) is movable into and out of engagement with a seat (16) and which when engaging the seat interrupts the fuel supply to the engine. 2. A theft prevention device as claimed in claim 1, c h a r a c t e r i z e d in that the lock (22) and the valve (10) to be inaccessible to unauthorized persons are enclosed in a casing (21, 24) , the lock being fastened to one wall (24) of the casing by means of a nut (23) disposed within the casing, and that a contact. (25)..connected in the electrical net-work of the vehicle is arranged, on the outer side of said wall (24) and operable by means of the key (27) serving to operate the lock (22) so that the current, supply to at least one of the electrical means of the vehicle is interruptible at the same time as the fuel—supply -is interrupted. 3. A theft prevention device as claimed in claim 1 or 2, c h a r a c t e r i z e d in that fuel supply • lines connected to the valve (10) and having the form of flexible pipes -(-3-1, 32) are tightly inserted in the casing (21, 24) and laid in a loop around the valve (10) . -.P' V - PI ' J

Inventors: SVENSSON L
Applicants: SVENSSON L
Application year: 1979
Main classification: B60R25
IPC codes: B60R25