US3358093A - Ignition switches - Google Patents

Description

2 Sheets-Sheet 1 Filed Feb. 2, 1967 Dec. 12, 1967 E. CRYER 3,358,093

IGNITION SWITCHES Filed Feb. 2, 1967 2 Sheets-Sheet 2 United States Patent 3,358,093 IGNITION SWITCHES Edward Cryer, Burnley, England, assignor to Joseph Lucas (Industries) Limited, Birmingham, England, a British company Filed Feb. 2, 1967, Ser. No. 613,656 Claims priority, application Great Britain, Feb. 17, 1966, Ser. No. 7,075/ 66 1 Claim. (Cl. 200-44) 7 ABSTRACT OF THE DISCLOSURE This invention relates to ignition switches for road vehicles, comprising as shown in the accompanying drawing, a casing having a rotor rotatably mounted therein, cam means acting to locate the rotor at any one of a number of positions relative to the casing, a contact as sembly arranged to complete circuits in certain positions of the rotor, and an additional switch having a fixed part carried by the casing and a movable part carried by the This invention relates to ignition switches for use in road vehicles.

A switch according to the invention includes a casing, a rotor, cam means acting to locate the rotor at any one of a number of positions relative to the casing, a contact assembly arranged to complete circuits in certain positions of the rotor, and an additional switch having a fixed part carried by the casing and a movable part coupled to the rotor for movement therewith.

One example of the invention is illustrated in the accompanying drawings wherein FIGURE 1 is a sectional side view of an ignition switch, FIGURE 2 is a sectional view on the line 22 inFIGURE 1, FIGURE 3 is an end view of the switch viewed in the direction indicated by the arrow A in FIGURE 1, and FIGURE 4 is a fragmentary perspective of part of the switch, and FIGURE 5 is a fragmentary sectional view on the line 5-5 in FIGURE 1.

The ignition switch illustrated in the drawings if of the key operated type having four operative positions, an off position in which the key may be removed from the switch, a first position achieved by rotating the key in a clockwise direction, in which ignition and auxiliary circuits of a road vehicle are energised, a second position, achieved by rotating the key further in a clockwise direction, in which a starter motor circuit of the vehicle is also energised, and a third position, achieved by rotating the key in a counterclockwise direction from the off position, in which only the auxiliary circuit is energised.

Referring to the drawings there is provided a cylindrical casing 11 which is stepped to provide ashoulder 18, and is closed at its wider end by anannular contact board 14. A hole in thecontact board 14 is closed by a resilient cup shapedmember 51 mounted in a synthetic resin material. Themember 51 is formed with a pair of arcuate outwardly extendingflanges 52 at its open end, which engageshoulders 15a formed in the inner face of theboard 14 to prevent withdrawal of themember 51.

A pair ofrivets 53, 54 extending through the base of themember 51 and secure a pair ofterminal blades 55, 56 to the outer face thereof, the heads of therivets 53, 54 formingcontacts 53a, 54a within themember 51.

Rotatable within the narrowercylindrical part 12 of the casing 11 is the core (not shown) of a cylinder lock, thepart 12 of the casing 11 constituting the barrel of the lock. Within the Wider part 11a of the casing 11 is arotor 16, rotatably supported at one end in themember 51 and secured at its other end to the core of the lock for rotation therewith.

Therotor 16 is moulded in a synthetic resin material and is formed with ahead 17 of substantially elliptical configuration (FIGURE 2). Thehead 17 abuts against theshoulder 18 of the casing 11 and extending axially from thehead 17 is a hollow substantiallycylindrical shank 19, having a pair of diametrically opposite, longitudinally extending flats (not shown), the end of theshank 19 being rotatably supported in themember 51. Theshank 19 is also formed with a pair of longitudinally extending diametrically opposite slots 22, in which are engaged the ends of an electricallyconductive roller 57. Aspring 58 housed within theshank 19, urges theroller 57 into contact withcam forms 59, 59a moulded on the inner wall of themember 51.

Surrounding theshank 19 is anannular contact plate 23 provided withprojections 24, the hole in theplate 23 being shaped complementarily to theshank 19 so that theplate 23 rotates therewith.

Associated with theboard 14 are fourcontacts 26, 27, 28, 29 each of which incorporates one or more terminal blades positioned externally of theplate 14 for connection to external circuits, and a contact portion on the interior of the plate, the contact portions extending into holes in aninsulating plate 35 over which theprojections 24 move.

Thecontact plate 23 is urged towards thecontact board 14 by aspring 36, one free end 36a of which is engaged in a furtherlongitudinal slot 22a in theshank 19, and the other free end 36b of which extends towards the inner wall of the casing 11.

Therotor 16 is provided with an axially extendingbore 38 of non-circular cross section with which is engaged a complementarily shaped spigot which extends from the core of the cylinder lock. By virtue of this engagement therotor 16 is rotatable with the core of the lock. In thehead 17 is aradial bore 39 containing aball 41 which is urged by aspring 42 into engagement with anarcuate cam track 43.

Thecam track 43 comprises three angularly spaceddepressions 44, 45, 46 and aramp 47. When the switch is in its off position theball 41 is engaged with thedepression 45 of thecam track 43 and theprojections 24 of thecontact plate 23 engage with theinsulating member 35. When the switch is in the off position theroller 57 is supported clear of thecontacts 53a, 54a by thecam forms 59, 59a against which theroller 57 is urged by thespring 58.

If it is required to energise the auxiliary circuit of the vehicle an ignition key is inserted into the core of the lock and rotated in a counterclockwise direction. Since the core of the lock, therotor 16, thecontact plate 23 and theroller 57 are not rotatable relatively to one another, angular movement of the key results in angular movement of theplate 23 relatively to theboard 14 and angular movement of theroller 57 relatively to thecam forms 59, 59a of themember 51. By rotating the key in a counterclockwise direction theplate 23 is moved to a position in which it bridges the input and auxiliary contacts and so completes the auxiliary circuit. Thecam forms 59, 59a of themember 51 are such that theroller 57 is maintained in a position clear of thecontacts 53a, 54a. When theplate 23 is in the position in which it completes the auxiliary circuit theball 41 engages thedepression 44 which prevents accidental rotation of the key and consequently theplate 23. By virtue of the engagement of the end 36a of thespring 36 with the slot 22 in theshank 19, thespring 36 is rotated with theshank 19.

To complete the ignition circuit of the vehicle the key is turned in a clockwise direction, theball 41 engages thedepression 46 and theplate 23 bridges the input, ignition and auxiliary contacts thereby completing the ignition and auxiliary circuits. The ends 36b of thespring 36 now engages a lug 37 formed as part of thecam track 43. To energise the starter motor of the vehicle the key is rotated further in a clockwise direction which forces theball 41 to ride up theramp 47 and causes thecontact plate 23 to bridge the input and starter contacts while maintaining the bridge between the input and ignition contacts. However, since the end 36b of thespring 36 is engaged with the lug 37, such further rotation of the key in a clockwise direction causes the spring to be twisted, so that if the key is now released thespring 36, now acting as a torsion spring, will return the switch to its first position in which theball 41 engages thedepression 46 and the ignition circuit is still completed but the starter motor circuit is broken.

The cam forms 59, 59a include a pair of diametrically opposite depressions in which the ends of theroller 57 locate when the ignition circuit is complete theroller 57 is urged by thespring 58 into the depressions. These depressions are suificiently deep to ensure that theroller 57 bridges thecontacts 53a, 54a so as to complete a circuit therethrough. Thus the switch completes two separate circuits and in eflect acts as a double pole ignition switch.

Thepart 12 of the casing 11 is externally screw threaded to facilitate mounting of the switch on the dash board or bulkhead of the road vehicle.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

An ignition switch comprising in combination a first hollow casing, a rotor, means mounting the rotor for angular movement within said first casing, a contact board closing one end of said first casing, said contact board having a central hole formed therein, movable contacts carried by the rotor, co-operating detent means on said first casing and said rotor serving to define operative positions of the switch, said movable contacts engaging respective fixed contacts carried by said contact board in said operative positions, a second casing non-rotatably engaged in said hole in the contact board, a pair of fixed contacts carried by said second casing, a conductive roller carried by said rotor and located within said second casing, a cam form on the inner surface of said second casing, and means urging said roller into engagement with said cam form, said roller riding on said cam form as the rotor is moved angularly, and the shape of said cam form being such that said roller bridges the pair of fixed contacts carried by said second casing in one of the operative positions of the switch.

References Cited UNITED STATES PATENTS 1,622,707 3/1927 Douglas 200-44 2,046,831 7/1936 Lowe ZOO-44 X 2,868,906 1/1959 Soreng 200-44 ROBERT K. SCHAEFER, Primary Examiner.

H. HOHAUSER, Antistant Examiner.

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