US3041425A - Circuit interrupting device for motor vehicle directional signal - Google Patents

Description

June 26, 1962 K. BOHMER CIRCUIT INTERRUPTING DEVICE FOR MOTOR VEHICLE DIRECTIONAL SIGNAL Filed Oct 1?. 1960 IN VEN TOR. KARL BOHMER ATTORNEY United States Patent M 3,041,425 CIRCUIT INTERRUPTING DEVICE FDR MOTOR VEHICLE DIRECTIONAL SIGNAL Karl Bohrner, 1987 Balfour, Sandwich East, Windsor, Ontario, Canada Filed Oct. 17, 1960, Ser. No. 63,010 1 Claim. (Cl. 200-113) This invention relates to circuit breakers or interrupters going through a repeating cycle automatically and adapted particularly, but not exclusively, for use in directional signal systems for motor vehicles.

One of the objects of the present invention is to provide an improved circuit breaker or flasher for motor vehicles whereby a number of serious disadvantages of prior de vices of this general nature have been overcome and largely eliminated without introducing new problems or increasing appreciably the costs involved.

Another object of the invention is to produce an improved circuit interrupter for directional signals of motor vehicles which includes a resistance wire adapted to be heated by passage of electric current and cooled after the current is interrupted or broken, and thus expanding and contracting repeatedly to exert a pulling force on the snap mechanism making and breaking the electric circuit at a pair of contact points.

A further object of the present invention is to provide an improved circuit breaker of the characterspecified in the preceding paragraph in which action of the circuit making and breaking mechanism is of a snapping nature, thus producing rapid separation of the contact points and reducing sparking thereat and also effecting movement of the movable contact point over a relatively long distance, thus producing sufiicient separation of the points and reliable action of the mechanism.

A still further object of the present invention is to provide a circuit breaker of the nature specified above which is characterized by smooth action, with no-shocks exerted on the resistance wire, thus eliminating a highly objectionable condition resulting in stretching of the resistance wire and changing its calibration after a relatively short period of operation. I l

A still further object of the present invention is to provide an improved circuit breaker of the above character which in spite of the smoothness of its action, retains a clicking noise highly desirable in devices of this nature. Such clicking is not found in circuit breakers including magnetic coils.

A still further object of the present invention is to provide a circuit breaker of the above nature having a very strong snap action.

It is a still further object of the present invention to provide a circuit breaker of the above character including means operating a separate set of contact points controlling a pilot light on the instrument panel of a motor vehicle. b 7

It is an added object of the present invention to provide an improved circuit breaker of the automatically repeating type, particularly advantageous for use in motor vehicles for directional signals thereof, which breaker is simple and rugged in construction, dependable operation, does not require oversensitive calibration and is relatively inexpensive to manufacture. Y Further objects and advantages of this invention will be apparent from the following description and appended claim, reference being had to the accompanying drawings forming a part of this specification, wherein like reference characters designate corresponding parts in the several views.

FIG. 1 is a perspective View showing an improved circuit interrupting device embodying the present invention, with a cover on.

I scription and not of limitation.

3,041,425 Patented June 26, 1962 FIG. 2 is an elevational view of the device with the cover removed but indicated in place in phantom lines. The front portion of the base plate carrying the front prong is removed for clarity of the drawing. The parts of the device are shown in a normal or cold position of the resistance wire and with the contact points open.

FIG. 3 is a view similar in part to FIG. 2 but showing the parts of the device with the contact points closed.

FIG. 4 is a perspective view illustrating the snapper spring separately.

FIG. 5 illustrates the L-shaped bracket separately.

FIG. 6 illustrates the T-shaped standard separately.

FIG. 7 is an elevational view taken on the snapper spring, the observer being presumed to look from right to left in FIG. 2.

FIG. 8 is a perspective view showing a modified construction of the L-shaped bracket and the T-shaped standard combined in said construction into one piece.

It is to be understood that the invention is not limited in its application to the details of construction and ar rangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of de- Particularly, it will be understood that the terms lower and upper as used in the specification and the claims relate to the position of the device as shown in the drawing, and are used for convenience of description; should the position of the device be changed such as by turning it upside down from the position shown in the drawing, the respective terms would have to be changed correspondingly. It will also be understood that the device illustrated herein may be used in any position without affecting its operation.

' In the drawing there is shown, by way of example, a circuit breaker embodying the present invention. Referring particularly to FIGS. 1-7, the device illustrated therein comprises a round base plate 10 made of an insulated material such as fiber. On said base plate 10 there is operatively mounted the circuit mechanism described below. A cup-shaped cover 11 covering the breaker mechanism may be made of any suitable material, such as sheet aluminum. Prongs adapted for inserting the device into a suitable plug for connecting it to the circuit are provided on the bottom surface of the plate 10. I

The mechanism comprises an L-shaped bracket generally designated by the numeral 15 and shown separately in FIG. 5. The bracket 15 includes a vertical bar 16, a horizontal bar 17, and a downwardly protruding bar 18 forming one of the prongs. The central portion of the horizontal bar 17 is pressed out as shown at 19 to provide a bifurcated end 1941 adapted to receive for anchoring therein one end of the thermal wire generally designated by the numeral 20. The bracket 15 is secured to the base plate 10 with the aid of a rivet 21. The upper end of the bar 16 of the bracket 15 is reduced in its width as indicated at 22 and its upper extremity is bent to provide a hook 23 for the purposes explained below.

With the bracket 15 there is operatively associated a T- shaped standard generally designated by the numeral 25 and shown separately in FIG. 6. The standard 25 has its knife edge 26 resting in a groove 27 provided at the juncture of the vertical bar 16 and horizontal bar 17 of the L-shaped bracket 15, see FIG. 2. The substantially horizontal bar provided in the upper end of the standard 25 is formed by punching out material of its upper portion to form a hook 28 for the purposes explained below and a bifurcated end 29 adapted to receive the end of the stretched portion of the resistance wire 20 retained therein in any suitable manner such as with the aid of suitable beads. For the purposes of better retention of said end the portion 29 is made inclined.

A snapper spring generally designated by the numeral 35 is shown separately in FIG. 4. It is in the form of an elongated resilient strip made of hard copper or other suitable material.

An elongated central opening 36 is cut out in the body of the resilient strip in such a manner as to extend over 'a substantial portion of its length and to form a tongue 37 extending from the lower end of the opening 36 toward its upper end but to terminate short of reaching the same and thus provide a free end 372. The tongue 37 is slightly pre-bent to ensure that pressing downwardly on its end 37c would cause further bending thereof. The lower end of the strip 35 carries two contact points 38 and a strip 39 with a contact point 39a for the purposes explained further below.

The snapper spring 35 is suspended on the hooks 28 and 23, as illustrated. It is important to appreciate that the distance designated by the letter d in FIG. 2, which is the distance between the surfaces of the hooks 23 and 23 contracted by the snapper spring 35, is smaller than the distance designated by the letter D in FIG. 4, which is the distance between the surfaces on the snapper spring 35 contacting the hooks 28 and 23, in the free position of said snapper spring 35. Therefore, mounting the snapper spring 35 on said hooks 28 and 23 causes the tongue 37 to be bent as illustrated in FIGS. 2 and 3, and, therefore, to exert upward force on the hook 23, in consequence whereof the top portion 35e of the snapper spring 35 exerts downward force on the hook 28, thus retaining the snapper spring 35 in place resiliently. In such a condition the contact point-carrying end of the snapper spring 35 comes to a certain position of balance. An angle bracket 40 having its horizontally extending portion riveted to the base plate together with the prong 41, with the aid of a rivet 42, carries on its vertical leg two contact points 43 cooperating with the contact points 38.

The thermal wire 20 having its lower end anchored at 19a, has the upper end of its strung portion 20a anchored in the end 29 of the standard" 25 in a suitable manner, as mentioned. The remaining portion 20b of the wire 20 is coiled, as illustrated, with the lower end of said coiled portion being connected in any suitable manner to the bracket 40 to provide an electrical contact therewith. The portion 20;: of the. wire 20 is tightly strung between the ends 19 and 29, as mentioned.

It will now be seen, in view of the foregoing, that the snapper spring 35 tends, when it is in its mounted position, to keep the upper end of the standard 25 in a certain position. With the Wire 20 being cold and in its strung condition, the contact points 38 and 43 are separated. It is this position that is illustrated in FIG. 2, wherein a clearance space 45 between the leg 16 of the bracket and the standard 25 is at its maximum.

Should there be electric current circulating in the circuit to which the prongs 1S and 41 are connected, the electric current will flow only through the resistance or thermal wire 20. Because of the high resistance characteristics of said wire, the same will become heated and expand, causing sufficient elongation of the strung portion a of the wire 24 to permit the end 29 of the standard 25 to move to the right. Such movement of the end 29 will cause snap movement of the snapper spring 35, with its contact points 38 contacting contact points 43 and thus providing a parallel circuit through the snapper spring 35. Such a condition of the mechanism is shown in FIG. 3. Under such condition, with the resistance of the parallel circuit completed by the snapper spring being incomparably smaller than that of the resistance wire 20, most of the current will flow through said parallel circuit, thus decreasing the flow of the circuit through the resistance wire 20 to the point when no heating thereof takes place.

'As a result, the Wire 20 cools rapidly, contracts, and are erts a strong pulling force on the end 29 of the standard vehicle.

25 moving it, in opposition to the mechanism action of the snapper spring 35, to the left. As such movement of the end 29 and of the top portion 352 of the snapper spring 35 continues, a point is reached when the lower end of the snapper spring 35 moves to the left with a snap, breaking the contact between the points 38 and 43 and thus opening the low resistance circuit. Thereupon, the current again flows through the wire 20 heating the same and repeating the cycle. Such operation of the device will continue as long as there is current in the circuit to which the prongs 18 and 41 are connected. It will be understood that the position of the lower end of the snapper spring 35 with .the wire 20 being cold may be experimentally determined, whereupon the position of the bracket 40 is thus located to have the contact points 38 and 43 closed when the wire 20 is hot, thus providing for the operation described above.

In order to ensure that the snapper spring 35 is retained in place on hooks 28 and 23, grooves 28g and 23g are provided on the hooks 28 and 23, respectively, as is best shown in FIGS. 5 and 6.

As mentioned above, the snapper spring 35 and the bracket 40 are provided with two sets of contact points, thus ensuring double contacting, making contact more reliable and decreasing the sparking between the contact points at the moment of separation, since breaking the contact will occur at the pair of contact points separating last.

In order to ensure that both sets of contact points come into full contact, raised spots 44 and 45 are provided on the snapper spring 35, as illustrated, thus enabling said snapper spring to adjust itself by slight axial rotation at the time of contacting to form a perfect contact at bothsets of contact points. It will be understood, however, that the invention is fully applicable with the use of a single rather than a double set of contact points. It will also be noted that forces exerted on the snapper spring 35 by the hooks 28 and 23 act along a straight line preventing the snapper from moving sidewise. 7

It is desired that a separate circuit controlled by the device be provided for operating the pilot on theinstrument panel of the motor vehicle, which light reproduces flashing of the signal lights provided on the front and back of the vehicle. ,In accordance with the invention, this is attained by the provision of the strip 39 secured to the lower end of the snapper spring 35 and carrying a contact point 39a adapted to cooperate with the contact point 46 provided on the bracket 47 mounted on the plate 10 and electrically connected with a third prong 48 with the aid of a rivet 49 holding the bracket 47 and the prong 48 to the base plate 10.

The arm 39 and its contact point 391; may be eliminated. In such a case the bracket corresponding'to the bracket 47 is placed along side the bracket 40 but electrically separated therefrom for the reasons of Wiring in the motor Then the two points on the snapper spring 35 would contact two contact points on separate brackets 40 and 47. The snapper spring may then be made wider, if desired.

It may also be desirable to extend the horizontal leg of the bracket 40 under the horizontal leg 17 of the L-shaped bracket 15 for connection to the plate 10 with the rivet 21. However, suitable insulation is provided to insulate the horizontal leg of the bracket 40 from said rivet 21 as well as the bracket 15. V

FIG. 8 illustrates a modified construction in which the L-shaped bracket 15 and the standard 25 of the construction of FIGS. l-7 are combined into a single physical member as illustrated. in said FIG. 8. Referring to said figure, an articulated spring bracket shown therein includes a horizontal bar 50 having a projection 51 corresponding to the projection 19 and adapted to receive the end of the wire 20 for anchoring. The prong 52 receives for anchoring the other end of the strong portion 21 of the wire 20. Portion 53 serves as the upper hook. The bent end 54 of the tongue 55 serves as the lower hook. A snapper spring 35 is mounted on the hook portions 53 and 54. Movement of the tongue 55 with respect to the vertical bar 56 of the bracket is attained by bending the bridge portion 57 at the bottom of the tongue. A separate prong serving the same function as the prong portion 18 is connected to the plate 10 by a rivet which passes through the hole 58 and thus holds the bracket to the plate 10. In other respects, the construction and operation of the device including such spring bracket is similar to those of the construction of FIGS. 1-7.

There is thus provided an improved circuit breaker of the automatically repeating cycle type, whereby the object of the invention listed above and numerous additional objects and advantages are attained.

I claim:

In a circuit breaking device, a base plate, a bracket forming one terminal, a stationary contact point provided on said bracket, a second bracket of an L shape with the horizontal bar of the L being secured to the base plate and the vertical bar of the L extending upwardly and having its end bent to form a hook, a T-s'haped standard associated with said L-shaped bracket and arranged thereon to have its vertical bar parallel to the vertical bar of said bracket and the horizontal bar of the T forming two hooks, an elongated resilient strip including two portions having their lower ends connected and carrying a movable contact point and their upper ends free, said strip being suspended on one hook of said T-shaped standard by the free end of one of said portions, with the hook of said L- shaped bracket bearing down on the end of the other portion of the resilient strip to put said portion in bending, a resistance wire strung between the other hook of the T- shaped standard and the end of the horizontal bar of the L-shaped bracket to exert pulling force thereon and to move it transversely toward said end and thus to move the point-carrying end of said strip away from the stationary contact, said resistance wire being adapted, when heated by passage of electric current therethrough to expand and to release said pulling force in order to cause the top of the T-shaped standard to move to the side of the permanent contact and thus to cause the contact-carrying point of said resilient strip to snap move toward the stationary contact and thus to close the circuit and thus to reduce the current flowing through said wire and to cause its cooling for re-asserting said pulling force and repeating the cycle.

References Cited in the file of this patent UNITED STATES PATENTS 2,242,769 Werner May 20, 1941 2,486,033 Kaminky Oct. 25, 1949 2,689,283 Pulva-ri Sept. 14, 1954 2,820,120 Flatt et a1. Jan. 14, 1958

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