US3457380A

US3457380A - Ignition switch utilizing a cam means for restrictive movement unless key is first moved to off position

Info

Publication number: US3457380A
Application number: US644668A
Authority: US
Inventors: Edward Cryer
Original assignee: Lucas Industries Ltd
Current assignee: ZF International UK Ltd
Priority date: 1966-06-09
Filing date: 1967-06-08
Publication date: 1969-07-22
Anticipated expiration: 1986-07-22
Also published as: GB1174904A; FR1525502A

Description

y 22, 1969 I CRYER 3,457,380

IGNITION SWITCH UTILIZING A CAM MEANS FOR RES CTIVE MOVEMENT UNLESS KEY 15 FIRST MOVED TO OFF P0 TION 1 Filed June 8, 1967 I 2 56 J 422 5 I2 United States Patent t 3,457,380 IGNITION SWITCH UTILIZING A CAM MEANS FOR RESTRICTIVE MOVEMENT UNLESS KEY IS FIRST MOVED TO OFF POSITION Edward Cryer, Burnley, England, assignor to Joseph Lucas (Industries) Limited, Birmingham, England Filed June 8, 1967, Ser. No. 644,668 Claims priority, application Great Britain, June 9, 1966, 25,728/66 Int. Cl. Hlllh 39/00 11.8. Cl. 200-26 1 Claim ABSTRACT OF THE DISCLOSURE An ignition switch for a road vehicle having a part rotatable with the rotor of the switch and cooperating with a cam track on the casing of the switch to prevent movement of the switch from a position in which the ignition circuit of the vehicle is completed to a position in which the starter motor circuit is completed unless the switch has previously been moved to a position in which both of said circuits are broken.

This invention relates to ignition switches for use in road vehicles.

An ignition switch for use in a road vehicle having ignition and starter circuits, comprising a casing, a rotor mounted for rotary movement within the casing, a first cam track formed within the casing having depressions corresponding to auxiliary, off and ignition positions, a radially directed ramp adjacent the ignition position corresponding to the start position and a stop adjacent the auxiliary position, a second cam track formed within the casing, said second cam track having a flat arcuate part constituting a ramp, the height of which increases from zero at a position diametrically opposite the depression corresponding to the off position to a maximum at a position diametrically opposite the end of the first mentioned cam track, the width of the ramp being constant up to a point diametrically opposite the depression corresponding to the ignition position, with the ramp having a radially directed shoulder at said point and the width of the ramp decreasing from a maximum at the shoulder to zero at the highest end of the ramp, spring means for the rotor, said rotor spring means having opposite ends, with one engaged with the rotor and the opposite end extending toward the inner wall of the casing, said rotor being provided with a spring-loaded member normally urged into engagement with said first cam track, said rotor having latch means located substantially diametrically opposite said spring loaded member, and further spring means operably related to said latch means normally urging said latch means towards the casing, the arrangement being such that when the switch is in either the off or auxiliary position, the latch means engages the flat part of said second cam track and to energize the ignition circuit, the rotor is turned to the ignition position whereby the latch means engages and rides up the ramp of said second cam track and the opposite free end of the rotor spring means engages the stop with further rotation of the rotor in the same direction moving the rotor to the stop position thereby twisting the rotor spring means and moving the latch means to the end of the ramp whereupon the latch means is urged by its spring means into engagement with the fiat part of the second cam track, and upon release of the rotor, the rotor spring rotating the rotor to its ignition position and during such return movement, the latch means follows the edge of the wide part of the ramp and is pushed inwardly with respect to the rotor against the action of its spring means with the rotor upon reaching the ignition position, the latch means clears the wider por- Patented July 22, 1969 tion of the cam track and being urged outwardly by its spring means into contact with the edge of the narrower part of the ramp so that if an attempt is made to move the switch again to its start position, the latch means engages the shoulder of the second cam track thereby preventing such movement.

One example of the present invention is illustrated in the accompanying drawings wherein:

FIGURE 1 is a side view partly in elevation and partly in cross section of an ignition switch,

FIGURE 2 is a view taken along the line 22 of FIG- URE 1, the view looking in the direction of the arrows, and

FIGURE 3 is a perspective view of a cam track forming part of the switch.

The ignition switch illustrated in the drawings 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 turning the key clockwise, in which the ignition and auxiliary circuits of a road vehicle are energized, a second position, achieved by turning the key further in a clockwise direction, in which the starter motor circuit is energized in addition to the ignition circuit, and a third position, achieved by turning the key counter clockwise from the off position, in which only the auxiliary circuits of the vehicle are energized.

Referring to the drawings, there is provided a cylindrical casing 11 which is stepped to provide a shoulder 18 and is closed at its wider end by a contact board 14. Rotatable within a narrower cylindrical part 12 of the casing 11 is the core (not shown) of a cylinder lock, with the part 12 of the casing 11 constituting the barrel of the lock. Within a wider part 15 of the casing 11 is a rotor 16 which is rotatably supported at one end in the contact board 14 and secured at its other end to the core of the lock for rotation therewith.

The rotor 16 is molded from a synthetic resin material and is formed with a head 17 of substantially elliptical configuration (FIGURE 2). The head 17 abuts against a shoulder 18 of the casing 11, and extending axially from the head is a hollow substantially cylindrical shank 19, formed with a pair of diametrically opposite longitudinally extending flats (not shown) and a longitudinally extending slot 22, with the end of the shank 19 being rotatably supported in a hole 21 formed in the contact board 14.

Surrounding the shank 19 is an annular contact plate 23 provided with projections 24, and the hole in the plate 23 is shaped complementarily to the shank 19 so that the plate 23 rotates therewith.

Associated with the board 14 are four

contacts

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

The contact plate 23 is urged towards the contact board 14 by a spring 36, one free end 36a of which is engaged in the slots 22 in the shank 19, and its free end 36b extends towards the inner wall of the casing 11.

The rotor 16 is provided with an axially extending bore 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, the rotor 16 is rotatable with the core of the lock. In the head 17 is a radial bore 39 containing a ball 41 which is urged by a spring 42 into engagement with a first arcuate cam track 43.

The cam track 43 comprises three angularly spaced depressions 44, 4'5, 46 which are engaged by the ball 41 in the auxiliary, off and ignition positions respectively of the switch. The cam track 43 further includes a radially directed ramp 47 upon whichthe ball 41 rides in the start position of the switch.

The face of the head 17 adjacent the shoulder 18 is formed with a radially extending channel 51 which is developed diametrically opposite the bore 42. The channel 51 commounicates at its inner end with an axially extending stepped bore 52 of generally rectangular cross section, with a shoulder 53 being defined between the channel 51 and the narrower part of the bore 52. A latch member 54 comprising a strip like portion 55 having a plate like portion 56 integral therewith and disposed at right angles thereto is engaged with the shoulder '53. The portion 55 extends from the channel '51 towards the casing and the portion 56 is housed in the wider part of the bore 52. A spring 57 is disposed between one wall of the bore 52 and the portion 56 of the member 54, and serves to urge portion 55 of the member 54 towards the casing 11.

The casing 11 is formed at a position diametrically opposite the first cam track 43 with a second arcuate cam track 58 which comprises a flat arcuate part 59 shaped adjacent the casing 11 to form a ramp 61. The height of the ramp 61 increases from zero at a position diametrically opposite to the depression 45 of the cam track 43 to a maximum at a position diametrically opposite the extremity of the cam track 43.

The width of the ramp 61 is constant up to a point diametrically opposite to the depression 46 in the cam track 43, where it is shaped to define a radially extending shoulder 62. The width of the ramp then decreases from a maximum at the shoulder 62 to zero at the highest end of the ramp. By virtue of the shape of the member 54, the portion 55 thereof is urged by the spring both radially towards the casing 11 and axially into contact with the cam track 58.

When the switch is in either its off or its auxiliary position, the portions 55 of the member 54 is engaged with the flat part 59 of the cam track 58.

When it is required to move the switch from its oif position, an ignition key is inserted into the core of the lock and is rotated. To energize the ignition circuit of the vehicle, the key rotated in a clockwise direction to turn the rotor 16. During the rotation of the rotor from the off position to the ignition position, the portion 55 of the member 54 engages and rides up the ramp 61 and the end 36b of the spring 36 engages a stop 37 formed as part of the cam track 43. Further clockwise rotation of the rotor 16 moves it from the ignition position, and in so doing twists the spring 36 and moves the portion 55 to the end of the ramp 61. Upon reaching the end of the ramp 61, the portion 55 of the member 54 is urged by the spring 57 back into contact with the fiat part 59 of the track 58. If the key is now released, the spring 36 rotates rotor 16 back to its ignition position. During the return movements from the start position to the ignition position, the portion '55 of the member 54 follows the edge of wide part of the ramp 61 shoulder 62 and prevents such movement. In order to move the-switch to the startposition, itmust first be moved to the off position wherein the portion '55 of the member 54 can engage the lower part of the ramp 61.

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

1. An ignition switch for use in a road vehicle of the type having ignition and starter circuits, comprising a casing, a rotor mounted for rotary movement within the casing, a first cam track formed within the casing having depressions corresponding to auxiliary, off and ignition positions, a radially directed ramp adjacent the ignition position corresponding to the start position and a stop adjacent said auxiliary position, a second cam track formed within said casing, said second cam track being provided with a flat arcuate part constituting a ramp, the height of which increasesfrom Zero at a position diametrically opposite the depression corresponding to the 0115 position to a maximum at a position diametrically opposite the end of the first cam track, the Width of the ramp being constant up to a point diametrically opposite the depression corresponding to the ignition position, with the ramp having a radially directed shoulder at said point and the width of the ramp decreasing from a maximum at the shoulder to zero at the highest end of the ramp, spring means operably related to said rotor, said spring means having opposite free ends with one end engaged with thev rotor and the opposite free end extending toward the inner wall of the casing, said rotor havinga spring loaded member normally urged into engagement with said first cam track, said rotor further having a latch means located substantially diametrically opposite said spring loaded member, and spring means normallyurging the latch means towards the casing, the arrangement being such that when the switch in either the off or auxiliary position, the latch means engages the flat part of said second cam track and to energize the ignition circuit, the rotor is turned to the ignition position whereby the latch means engages and rides up the ramp of said second cam track and the opposite free end of said rotor spring means engages the stop and further rotation of the rotor in the same direction moves it to the start position thereby twisting the rotor spring means and moving the latch means to the end of the ramp with said latch means upon reaching the end of said ramp being urged by its spring means into contact with the flat part of said second cam track and upon release of the rotor, the rotor spring rotates said rotor to its ignition position during which movement said latch means follows the edge of the wide part of the ramp and is pushed inwardly against the action of its spring means and with said rotor reaching the ignition position, the latch means clears the wider portion of said second cam track and is urged outwardly by its spring means into contact with the edge of the narrower part of the ramp.

References Cited FOREIGN PATENTS 6/1962 Germany. 3/1961 France.