Patent GB-198072-A (GB)
Title: Improvements in and relating to anti-theft devices for motor road vehicles
IPC: B60R25/10
Filed: 1922-02-27
Abstract: 198,072. Morgan, J. Feb. 27, 1922. Guarding against unauthorized use. - The circuits to the sparking plugs of the engine are closed by contacts in a plurality of rotatably adjustable members when the members are set in predetermined positions, but when set in sufficiently incorrect positions, a circuit to an alarm is closed. When a door giving access to the apparatus is opened, the bonnet is locked and rotation of the Cardan shaft sounds an alarm. The apparatus is shown diagrammatically in Fig. 9, and consists of a number of rotatable discs 9 and two non- rotatable discs 15, 16 of non- conducting material. The discs are engaged in a casing and may be moved lengthwise into the operative position shown in Figs. 1 and 4, or may be separated as shown in Fig. 3. In the construction shown suitable for a four cylinder engine, the rotatable discs 9 are each provided with twelve equally spaced spring contacts, of which seven contacts n are connected by strips 14 to a central metal rod 2, one end of which is connected by the lead 6 to a battery 7. The discs 9 may be set in any desired position by means of letters or numerals on their peripheries. Of the contacts in the end blocks 15, 16, four in block 16 are connected to the sparking plugs and the corresponding four on block 15 are connected to the magneto 24 or other source of supply. The middle contacts g, i are connected respectively to an alarm j and to the battery 7. For normal running of the engine, the rotatable discs are turned so that their isolated contacts l connect the magneto terminals to the sparking plugs while the middle contacts g, i are connected to one another so that the alarm j is sounded by the battery 7 if the switch 25 is closed. If the rotatable discs are disarranged to such an extent that at least one is turned until one of its connected contacts n :is in line with the alarm contact i, and the discs are then moved longitudinally into engagement, the circuit through the battery and alarm is completed through the central rod 2 and the contact i. The central rod 2 passes through slots 22 in the casing in the front of which is arranged a vertically slidable door 20. When the door is raised, the spring contacts 21 press the spindle and the parts carried thereby out to the limit allowed by the slots 22 so that the block 15 clears the shoulder 19 in the casing and the discs may be separated. Before the door can be again closed the discs and blocks must be re-engaged so that the block 15 engages behind the shoulder 19. The door is also connected bv a cable t to a bonnet lock x in such a way that the bonnet is looked when the door is open. To ensure the soundmg of the alarm if the car is towed with the rotatable discs disengaged. a contact m, Fig. 8, is adapted to close a switch n<1> when the cardan shaft p is rotated. The contact m is carried by a sleeve o which is drawn to the left against the action of a spring by a cable s when the, door 20 is closed. If the cardan shaft is rotated when the door 20 is open, the contact m rides up the spiral collar q and closes the switch n<1> which sounds the alarm.