US1880743A - Automatic switch - Google Patents

Description

E. W. BOTTS oct. 4, 1932.

AUTOMATIC SWITCH Filed NOV. l5, 1929 ATTORNEY Patented Oct. 4, 1932 UNITED STATES EDWARD W. IBOTTS, F CHICAGO, ILLINOIS AUTOMATIC SWITCH Application led November 13, 1929. Serial No. 406,775.

My invention relates to improvements in automaticmake and break switches for automobile stop lights and the like and has for one object to provide a super-sensitive make and break switch which may be enclosed in a light and portable housing and which may be placed in series with automobile stop or signal lights and wherein the assembly may be mounted asvpart of the wiring system supported by the wires and without relation to any other part of the vehicle. Other objects `will appear from time to time throughout the specication and claims.

v My invention is illustrated more or less diagrammatically in the accompanying drawing, wherein- Figure 1 is an end view of the device; Figure 2 is a section along the line lill-lll of Figure l; Figure 3 is a section along the line Ill-lill of Figure 1 Figure 4 is a detail on an enlarged scale.

Like parts are indicated by like characters throughout the specification and drawing.-

A is a housing. It is preferably cylindrical and preferably made of ber or other suitable insulating material. It is closed at each end by plugs A1 A2 of fibrous material, preferably asbests or mineral wool. The

* purpose of these plugs is to furnish a support and limit'for the inward flow into the tube or housing of the insulating, sealing ends or closures A3 A* which are poured in place and permanently close the unit.

B is a switch frame contained within the housing and insulated from the electric parts as indicated. Mounted on the upper end of the frame B is a switch arm B1 made of two materials having different co-eflicients'of expension as for instance brass and iron, which materials also serve as a conductor. This arm is rigidly mounted on and is in electrical connection with the frame B. In opposition to this arm is a similar switch arm B2 which is supported on the frame B and insulated therefrom. Wound about this arm is a resistance coil B3 insulated of course therefrom. One terminal of .this coil is connected as at B4 to the anchored base of the arm B1, the other terminal is connected as at B5 to the enlarged 50 base of the arm B2. Make and break points B6 are mounted in opposition to the free ends of the switch arms B1 B2.

A conductor C having an insulated jacket C1 embedded in the plug A4 is connected to 55 the switch arm B2. A conductor C2 insulated at C3 and embedded in the plug A3 engages the arm B1. rlhese two conductors by their engagement with the ends of the arms B1 and B2 which are rigidly mounted on the frame B, eo h old the frame, the switch arms, and the resistance coil firmly in place in the housing, the ber plugs having no function so far as holding the parts together or in place are concerned, they being there only for the purpose ce as above indicated of preventing the liquid from which the plug is cast flowing too far into the housing. C* is a cup extending outwardly Jrom the plug A3 and containing a resistance coil C5, one end of which is in electu tric circuit with the arm B1, the other end C8 leading out from the cup. The wire C is preferably connected to the battery, generator, or other suitable source of electric power. rlhe wire()6 is grounded. The wire 75 C2 is connected through a main control switch to the light circuit. rl`his switch maybe the usual type of switch responsive to the movement of the foot pedal'of anautomobile to indica-te a stop or may be a signal switch controlled by the hand of the operator or any other type of switch manually or automatically controlled to operate a lamp signal or other circuit.

The two switch arms are both of them bimetallic so that they will both respond equally to changes in the normal temperature of the apparatus and render it immune to change resulting from changes in location of the structure or changes in the temperature to which the entire apparatus is exposed, thus making it possible to have a comparatively sensitive switch element. This is important if the device is, for instance, applied to an automobile in the FarNorth or in theTropics. The reaction of the two switch arms to such change being the same `willnot cause any change in their operation.

When current flows through the coil B3, it will be heated to the point wherethe arm B2 will move over to close a circuit through the points B". The arms B1 B2 being much better conductors than the'coil B3 and its terminals, current suiicient to heat the coil will no longer pass through. The arm will cool and the switch will go back to break the circuit when the coil will again be heated depending upon the size of the coil and the sensitiveness ofthe switch arms. The time during which the circuit is closed through the points B6 may be varied at the will of the manufacturer. The total resistance in the light circuit through the resistance coil B3 is enough to prevent lighting of the lamp but when the switch points Be are closed and the resistance coil B3 is short circuited the current can light the lamp. The result of this is that when the main switch, is closed, the lamp will flicker on a controlled rate. The resistance of the coil Ct5 is so great that when the main switch is closed, the grounding eect through the coil C5 and the conductor Ca is negligible.

The wire C being grounded enables a small amount of current to How at all times to maintain the resistance coil B3 in an initial- 1y heated condition which will cause the switch to be in constant slow operation and be in readiness to instantaneously iiash the stop light or other signal when the main switch is closed. Moreover, the closing of the main switch causes the additional current taken by the stop light to ow through the coil B3, whereupon the coil is heated more rapidly and 4the make and break points B6 are opened and closed at a much faster speed than during the initial heating or slow operation perio It will be understood that the device shown in Filr'es'Q and 3 is about six times full size andt e unit may be placed in the wiring circuit where desired without any special mounting, being supported only by the wires themselves.

I claim:

1. An automatic make and break switch comprising a permanently closed generally elongated housing, conductor wires extending into the housing through the opposed ends thereof, a supporting frame contained within the housing and supported on the ends ofsaid wires, the make and break switch comprising a pair of opposed bi-metall'ic heat responsive arms with contact points in opposition.

2. An automatic make and break switch comprising a permanently closed generally elongated housing, conductor wires extending into the housing throu h the opposed ends thereof, a supporting rame contained within the housing and supported on the ends of said wires, the make and break switch comprising a pair of opposed bi-metallic heat responsive arms with contact points in opposition, a resistancecoil wound about one of said arms and in series with the two arms whereby when a circuit is closed between the arms, the coil is short circuited.

3. An automatic make and break Switch comprising a substantially tubular housing having closed ends, conductor wires extending intothe interior of the housing through its ends, a pair of opposed bi-metallic heat responsive arms having their outer ends electrically connected to and supported by said wires, said arms having opposed contacts at their free ends, an insulated supporting base within the housing having its ends rigidly secured to the arms adjacent the outer ends thereof, whereby said arms are maintained in operative position, and a resistance coil wound about one of said arms, said coil having its ends connected respectively to said arms.

4. An automatic make and break device comprising a substantially tubular housing having closed ends, conductor wires extending into the interior of the housing throu h its ends, thermostatic switch elements in sald housing in circuit with said wires, a heating coil to heat one of said elements, said coil being connected between said elements, and a high resistance connection to the other of said elements.

5. An automatic make and break device comprising a substantially tubular housing having closed ends, conductor wires extending into the interior of the housing throu h its ends, thermostatic switch elements in sald housing in circuit with said wires, a heating coil to heat one of said elements, said coil being' connected between said elements, and a high resistance coil surrounding one of said conductors having one end connected to the other of said elements.

6. An automatic make and break device comprising a substantially tubular housing having closed ends, conductor wires extending into the interior of the housing through its ends, thermostatic switch elements in said housing in circuit with said wires, a heating coil to heat one of said elements, said coil being connected between said elements, and a high resistance coil surrounding one of said on said support, one of saidelements being responsive to temperature changes1 a heating coil to heat the temperature responsive element, said coil being connected between said elements, and auxiliary connections to said coil to enable the coil to initially heat the temperature 'responsive element) Signed at Chicago county of Cook and State of Illinois, this 23rd day of October,

1929. EDWARD V. BOTTS.

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