US2010984A

US2010984A - Lock

Info

Publication number: US2010984A
Application number: US748656A
Authority: US
Inventors: Gerald John W Fitz
Original assignee: Briggs and Stratton Corp
Current assignee: Briggs and Stratton Corp
Priority date: 1934-10-17
Filing date: 1934-10-17
Publication date: 1935-08-13
Anticipated expiration: 1952-08-13

Description

A 1935- J. w. FITZ GERALD 7 2,010,984

LOCK

Filed Oct. 17, 1934 {/5 I 5 27/72? WE/ZGEFi/d Z'ip W with the sparkplugs ll.

Patented Aug. 1935 24510.ne v

John W -Fitz Gerald, Milwaukee, Wis, assignor to,

Briggs 81: Strait-ton Corporation, Milwaukee, Wis.,acorporation of Delaware Application October 1-7, 1934, Serial No. 748,656

, I rciaims; (011231-1465) This invention relates to locking means for E6 of the ignition switch, the other terminal automobiies and refers more particularly to ignition locks.

Automobiles are now generally provided with coil locks of the armored type wherein the lock switch and the cable extending from the loci: switch to the induction coil are enclosed in an armor. The necessity for an armored cable has objections and has not provided the degree of security desired. r

' It is therefore an object of this invention to provide protection for the ignition of an automobile which is not dependent upon an armored sheath for the cable, but which, through the provision of a maze of wires in the cable, only one of which connects with the coil, aifords adequate protection against theft.

With the above and other objects in view which will appear as the description proceeds, this invention resides in the novel construction, combination and arrangement of parts substantially as hereinafter described and morefparticularly defined by the appended claims, it being understood that such changes in the precise embodiment of the hereindisclosed invention may be made as come within the scope of the claims.

The accompanying drawing illustrates one complete example of the physical embodiment of the invention constructed according to the best mode so far devised for the practical application of the'principles thereof, and in which:

The single figure is a diagrammatic illustration of one embodiment of this invention.

Referring now more particularly to the accompanying drawing, the numeral 5 represents a lock switch of any conventional design connected through a cable 6 with a spark coil indicated generally by the numeral '1.

The coil 1 comprises a primary 8 and a secondary 9 in inductive relationship. One end of the secondary, as is customary, is connected with the distributor arm jlll to be connected thereby The opposite end of the secondary is connected, to the adjacent end of the primary to be grounded upon closure of the breaker l2 connected in parallel with the usual condenser l3. i

The opposite end of the primary 8fis connected to a conductor I4 whichpasses through the cable 6 and is one of a maze of wires I 5. For purposes of illustration, the conductor, 14 has been shown heavier than the other conductors l 5, but in practice'all of the Wires have identically the same appearance. s i

The conductor [4 is connectedto one terminal ll of which is connected to the battery 18 so that uponactuation of the ignition switch-to its closed position illustrated, current is supplied to the primary of the coil.

The switch is controlled by a lock indicated generally by the numeral mane operated by the, proper key .20. i 1

As' illustrated, both the ignition lock switch .5

and the coil 1 are encased in metal housings "2i These resistance elements have substantially the same resistance as the primary 8, for a purpose 20 to be hereinafter described.

The outer casing of the cable is not armored, consequently, in an attempted theft of the automobile, the natural procedure is to first cut the cable and connect the .ends of all of the wires of the part remaining connected to the coil, to the battery in an attempt to pass current through the primary of the coil. Upon so connecting all of the wires with the battery, current does pass through the primaryof the coil, but it also passes through the resistance elements 23 which are in parallel with the primary of the coil 8. As a resuit, the coil will not function.

If upon discovering this fact, the thief attempts to locate the proper wire through the use of an ammeter inthe circuit, he is again met with failure in. that all of the wires when measured one at a time will show the same ammeter reading inasmuch as the resistance elements 23 have substantially the same resistance as the coil 8.

Hence, it will be obvious that the possibility of defeating the lock afforded by this invention is slight and requires so much time that unless the thief has an extra coil which can be connected in the ignition circuit in place of the coil with which the engine is equipped, the attempted theft will be successfully thwarted.

What I claimas my invention is:

1. In an ignition system for automotive vehicles including an induction coil having a primary and a secondary, and an ignition switch, both of which are encased, a cable connecting the ignition switch and the coil and having its ends firmly secured in the casings thereof, said cable comprising a plurality of Wire-gone of said wires connecting the ignition switch with one end of the primary of the induction coil, electrical resistance means having one end connected with the other wires at their ends adjacent the induction coil, and means connected to the opposite ends of the induction coil primary and the electrical resistance means to ground the same.

2. In an ignition system for automotive vehicles including an induction coil having a primary and a secondary, and a breaker through which one side of the induction coil primary is intermittently grounded and having an ignition switch to control the supply of current to the primary of the induction coil, a multi-wired cable con necting the ignition switch and the induction coil, only one wire of which provides proper connection between the switch and the primary of the coil, and means to connect the remaining wires at their ends adjacent the coil with the breaker whereby upon severance of the cable and the connection of all of the wires of that part of the cable. leading to the coil with a source of current, the coil is prevented from functioning.

3. 1 In an ignition system for automotive vehicles including an induction coil having a primary and a secondary, and a breaker through which one end of the primary is connected with the ground, an ignition switch to control the connection of the primary with a source of current, a multiwired cable connecting the ignition switch and the coil, one wire of which provides proper connection between the switch and the primary of the coil, electrical resistance means connecting the remaining wires of the cable with the breaker so that said electrical resistance means is in parallel with the primary of the induction coil whereby upon severance of the cable and the connection of all of the wires of that part of the cable connected with the coil with a source of current, the passage of current through said electrical resistance means precludes the functioning of the coil.

4. In an ignition system for automotive vehicles including an induction coil having a primary and a secondary, and a breaker through which one end of the primary is connected with the ground, an ignition switch to control the connection of the primary with a source of current, a multi-wired cable connecting the ignition switch and the coil, one wire of which provides proper connection between the switch and the primary of the coil, electrical resistance means connecting the remaining wires of the cable with the breaker so that said electrical resistance means is in parallel with the primary of the induction coil whereby upon severance of the cable and the connection of all of the wires of that part of the cable connected with the coil with a source of current, the passage of current through said electrical resistance means precludes the functioning of the coil, said electrical resistance means having substantially the same resistance as is offered by the primary of the coil so as to render it impossible to select the proper wire by means of ammeter readings.

JOHN W. FITZ GERALD.