US3270317A

US3270317A - Brake light switch

Info

Publication number: US3270317A
Application number: US321973A
Authority: US
Inventors: Edelblut Johann
Original assignee: Individual
Current assignee: Individual
Priority date: 1963-11-06
Filing date: 1963-11-06
Publication date: 1966-08-30
Anticipated expiration: 1983-08-30

Description

0, 1966 J. EDELBLUT BRAKE LIGHT SWITCH Filed Nov. 1963 lNVENTO/P JOHANN EDELBLUT ATTORNEYS United States Patent 3,270,317 BRAKE LIGHT SWITCH Johann Edelblut, Frankfurt am Main, Seckbach, Germany, assiguor to Alfred Fetz, Detroit, Mich. Filed Nov. 6, 1963, Ser. No. 321,973 8 Claims. (Cl. 340-71) This invention relates to a brake light switch and more particularly to a switch mechanism for automatically actuating a signal light on a motor vehicle when the motor vehicle comes to a stop.

The conventional stop light arrangement on a motor vehicle is designed such that the stop light is actuated when the brakes are applied but the stop light is extinguished when the brakes are released. Thus, if a motor vehicle comes to a complete stop on the highway and after stopping, the brakes are released, the stop light will be extinguished and there will be no warning to a following vehicle that the vehicle ahead has come to a complete stop.

The object of the present invention is to provide a novel switch mechanism which is responsive to the speed of the vehicle for energizing a signal light whenever the vehicle comes to a complete stop or, if desired, when the speed of the vehicle is diminished to a predetermined low value.

In the drawing:

FIG. 1 is a sectional view of the switch mechanism of the present invention taken along the lines II of FIG. 2.

FIG. 2 is a sectional view of the switch mechanism taken along the line II-II in FIG. 1.

FIGS. 3 and 4 are views showing alternate constructions for the switch contact members.

The switch mechanism of the present invention includes a housing 1 in which is journalled a rotor 2 by means of a shaft 3. In the embodiment illustrated in FIGS. 1 and 2, the rotor 2 is designed to be rotated in the direction of the arrow designated 4 by means of a cable or the like, not illustrated, connected to the projecting end of shaft 3. The driving cable would be connected to the drive shaft or other part of the vehicle I so that the speed of rotor 2 would be proportional to the speed of the vehicle. Housing 1 contains sufficient liquid such as oil therein to completely submerge the rotor. The housing is adapted to be filled with oil by means of a filler plug 6 in the top wall 7 of the housing.

The housing itself comprises a body portion 11 with a cover plate 8 secured to one side thereof and sealed in fluid tight relation by screws 10. Housing 1 is formed of an electrical insulating material such as Bakelite or the like. At one side of the housing, there is mounted within the housing a leaf spring member 13 which is secured to the housing by means of a screw 14 passing through a bushing 12 in the wall of the housing. Nuts 15 on the outer end of screw 14 secure the screw and at the same time provide a terminal for a wire conductor 16 extending from a signal light 17. A manual switch 18 is in series circuit with signal light 17 and battery 19. The battery is grounded as at 20. The housing 1 also includes a second electrical terminal in the form of a screw 24 connected to ground 20 by a conductor 25. Screw 24 is threaded into an electrical conducting fitting 22 which is in turn threaded into the boss 9 of cover plate 8 in which the shaft 3 is journalled. Electrical connection between shaft 3 and fitting 22 is provided by means of a contact 21 which is biased against the inner end of shaft 3 by an electrical conducting spring 23.

The circuit between

terminals

15 and 24 is adapted to be closed by a switch arm 26 mounted at the free end of leaf spring 13 and an arcuate shoe 27 which is fixedly supported at the free end of spring arm 26. Spring 13, arm 26 and shoe 27 are all formed of electrical conducting materials. Shoe 27 is of arcuate shape and forms a segment of an are having a diameter slightly greater than the diameter of rotor 2. Spring 13 and arm 26 supports shoe 27 so that the shoe normally contacts the outer periphery of rotor 2 only at the limited portion designated 29. The remainder of shoe 27 is spaced slightly from the peripheral surface of rotor 2 so as to provide a tapered slot 28 between shoe 27 and the periphery of rotor 2. The leading end of shoe 27 is bevelled inwardly as indicated at 30 and the trailing end of shoe 27 is outwardly bevelled as indicated at 31.

In the operation of the switch mechanism illustrated in FIGS. 1 and 2, when the vehicle is at rest and the switch 18, which may be the ignition switch of the vehicle, is turned to the on position, a circuit is completed from battery 19 through switch 18 and through signal light 17 to the terminal 15 on the housing. The circuit continues through screw 14, spring 13, arm 26 and shoe 27 to the rotor 2. The circuit is completed to ground through the shaft 3, contact 21, spring 23, fitting 22, terminal 24 and conductor 25. Now, when the vehicle is travelling, shaft 3 rotates in the direction of the arrow designated 4 and at a speed proportional to the speed of the vehicle, As the rotor 2 rotates in the clockwise direction illustrated in FIG. 1, there is a tendency for fluid to be drawn into the tapered slot 28 and, depending upon the viscosity of the oil 5 and the speed of rotation of the rotor, a light film of oil will be drawn between the inner surface of shoe 27 and the outer surface of rotor 2 of sufiicient thickness to open the circuit at 27, 29. Thus, when the vehicle is travelling above a predetermined low speed, the signal light 17 will be extinguished but when the vehicle comes to a stop or the speed thereof is diminished below a predetermined value depending upon the adjustment of spring 13, signal light 17 will be illuminated and will serve as a warning to the cars following that the vehicle ahead is either travelling very slowly or has come to a complete stop. A slot 32 permits adjustment of spring 13.

It will be observed that with the arrangement illustrated in FIGS. 1 and 2, if the vehicle is travelling in reverse, shaft 3 will rotate in a counterclockwise direction and the bevelled edge 31 on the trailing end of the shoe will prevent the oil in housing 1 from building up between shoe 27 and the periphery of the rotor 2. Thus, the signal light 17 will remain illuminated when the vehicle is travelling in reverse.

In the arrangement shown in FIG. 3, the switch arm 26a supports a shoe 27a. Unlike the shoe 27 illustrated in FIGS. 1 and 2, the shoe 2711 has a radially inwardly extending arcuate bump 29a at the center thereof which provides localized contact between the peripheral surface of rotor 2 and shoe 27a. The opposite ends of shoe 27a are bevelled inwardly as indicated at 30a and 301). Since shoe 27a has "a diameter slightly greater than the diameter of rotor 2,

tapered inlet slots

34 and 35 are provided on opposite sides of bump 29a between the outer surface of the rotor and the inner surface of shoe 27a. With this arrangement, it will be observed that if the vehicle is driven in reverse at a speed above a predetermined low value, the signal light 17 will be extinguished.

The arrangement shown in FIG. 4 is somewhat similar to that illustrated in FIGS. 1 and 2 with the exception, however, that two shoes 27b and 270 are provided. These two shoes are supported by switch arms 26b and 26c, respectively. The two shoes 27b and 27c are disposed on opposite sides of rotor 2 and arranged such that when the rotor is turning in the direction of the arrow 4, shoe 27!; moves out of contact with rotor 2 and when the rotor is turning in the opposite direction, that is, in the direct-ion designated by arrow 33, shoe 27c is caused to move out of contact with rotor 2. In this arrangement, two lights may be operated by the respective switch arms.

I claim:

1. A brake light switch for a motor vehicle comprising a liquid filled housing, a rotor journalled in said housing, means for driving the rotor in accordance with the speed of the vehicle, an arcuate contact shoe biased against the peripheral surface of the rotor, said contact shoe having a diameter slightly greater than the diameter of the rotor so that there is only localized contact between the shoe and the peripheral surface of the rotor, the arcuate portion of the shoe out of contact with the rotor forming with the periphery of the rotor an inlet slot extending to the contacting portions of the shoe and rotor, the arrangement being such that when the rotor is rotated above a predetermined speed, the liquid in the housing is forced into said inlet slot to shift the shoe out of contact with the rotor, a light, a source of electric current and means forming a series circuit including said light, current source, rotor and shoe.

2. A brake light switch as called for in claim 1 including a leaf spring mounted on said housing and supporting said shoe.

3. A brake light switch as called for in claim 2 Wherein the leaf spring is mounted on the housing by a screw which forms an electrical terminal on the housing, said shoe and said spring being formed of electrical conducting materials and said housing being formed of an electrical insulating material.

4. A brake light switch as called for in claim 1 wherein said housing is formed of an electrical insulating material and including an electrical conducting member in said housing contacting said rotor and forming a portion of said electrical circuit.

5. A brake light switch as called for in claim 1 wherein said shoe is fashioned with a curved radially inwardly extending projection on the inner surface thereof which is of relatively short circumferential extent.

6. A brake light switch as called for in claim 1 wherein said shoe at the end thereof out of contact with the rotor is formed with an inwardly inclined bevel.

7. A brake light switch as called for in claim 1 including a second contact shoe similar to the first contact shoe and positioned on the opposite side of the rotor as the first contact shoe, said two contact shoes being arranged such that when the rotor is rotated in one direction, one of said contact shoes is caused to move out of engagement with the rotor and when the rotor is rotated in the opposite direction, the other contact shoe is caused to move out of engagement with the rotor.

8. A device for use on a motor vehicle comprising a liquid filled housing, a rotor journalled in said housing, means for driving the rotor in accordance with the speed of the vehicle, an arcuate contact shoe biased against the peripheral surface of the rotor, said contact shoe having a diameter slightly greater than the diameter of the rotor so that there is only localized contact between the shoe and the peripheral surface of the rotor, the arcuate portion of the shoe out of contact with the rotor forming with the periphery of the rotor an inlet slot extending to the contacting portions of the shoe and rotor, the arrangement being such that when the rotor is rotated above a predetermined speed, the liquid in the housing is forced into said inlet slot to shift the shoe out of contact with the rotor, an electrically actuated device, a source of electric current and means forming a circuit including said electrically actuated device, current source, rotor and shoe for operating said electrically actuated device in response to the making and breaking of contact between the shoe and rotor.

References Cited by the Examiner UNITED STATES PATENTS 2,678,977 5/1954 Thatcher 200 2,698,365 12/1954 Gaylord et al 340-263 X 2,751,453 6/1956 Gaylord et al. 20080 2,754,386 7/1956 Gaylord ZOO-80 2,832,864 4/1958 Rapp 340 71 X NEIL C. READ, Primary Examiner.

A. H. WARING, Assistant Examiner.

Claims

8. A DEVICE FOR USE ON A MOTOR VEHICLE COMPRISING A LIQUID FILLED HOUSING, A ROTOR JOURNALLED IN SAID HOUSING, MEANS FOR DRIVING THE ROTOR IN ACCORDANCE WITH THE SPEED OF THE VEHICLE, AN ARCUATE CONTACT SHOE BIASED AGAINST THE PERIPHERAL SURFACE OF THE ROTOR, SAID CONTACT SHOE HAVING A DIAMETER SLIGHTLY GREATER THAN THE DIAMETER OF THE ROTOR SO THAT THERE IS ONLY LOCALIZED CONTACT BETWEEN THE SHOE AND THE PERIPHERAL SURFACE OF THE ROTOR, THE ARCUATE PORTION OF THE SHOE OUT OF CONTACT WITH THE ROTOR FORMING WITH THE PERIPHERY OF THE ROTOR AN INLET SLOT EXTENDING TO THE CONTACTING PORTIONS OF THE SHOE AND ROTOR, THE ARRANGEMENT BEING SUCH THAT THE ROTOR IS ROTATED ABOVE A PREDETERMINED SPEED, THE LIQUID IN THE HOUSING IS FORCED INTO SAID INLET SLOT TO SHIFT THE SHOE OUT OF CONTACT WITH THE ROTOR, AN ELECTRICALLY ACTUATED DEVICE, A SOURCE OF ELECTRIC CURRENT AND MEANS FORMING A CIRCUIT INCLUDING SAID ELECTRICALLY ACTUATED DEVICE, CURRENT SOURCE, ROTOR AND SHOE