US1942024A - Electrical interrupter - Google Patents

Description

E E FREY ELECTRICAL INTERR-UPTER Filed Feb. 6, 1933 Jan. 2, 1934.

Patented Jan. 2, 1934 PATENT OFFICE ELECTRICAL INTEBRUPTER Elmer E. Frey, Los Angeles, Calif., assignor to Kittle Manufacturing 00., Los Angeles, Calif. a

corporation of California Application February 6,1933. Serial Na. 655,420

Claim.

This invention relates to electrical interrupters, and. particularly to magnetically operated contact devices for momentarily flashing an electric lamp at predetermined intervals.

5 It is common to illuminate certain street traflic signs, such as "stop signals, so that they will display a warning to trafiic at night as well as during the day. Various types of electric lamps have been used for this purpose, and in many 1. instances electromagnetically operated flashers have been employed to flash the lamp and to make it more effective as a warning signal. Furthermore, because of their high efliciency and appropriate color, neon lamps have been frequently employed as the source of illumination in such signs, and these lamps require for their operation a relatively high potential. The high potential may be conveniently obtained by intermittently applying a low potential, (110 volts or less) to the primary winding of a transformer, the secondary of which is connected to the neon tube. Each time the primary circuit is closed and opened the sudden change in the magnetic flux produced in the transformer develops a high potential in the secondary winding sufficient to flash the neon lamp.

Various types of interrupters may be employed for periodically closing and opening the electrical circuit in an illuminated sign of the type described, probably the simplest being magnetically operated contacts actuated by the current to be interrupted. A difficulty has been to obtain a simple interrupter that is inexpensive to make, reliable in operation, requires little maintenance, and opens and closes the circuit at the desired intervals.

An object of the invention is to provide an interrupter having the atom-mentioned desirable characteristics.

Other more specific objects and'features of the invention will be apparent from the following detailed description which refers to the drawing.

In the drawing:

Figure 1 is-a front elevation view of the interrupter in accordance with the invention, with the cover plate broken away to show the mwhanism.

Figure 2 is a side elevation view of the same device.

Figure 3 is a detailed view of the oscillatable element of the interrupter illustrating the operation of the device.

Figure 4 is a schematic diagram illustrating a circuit in which my interrupter may be used.

The assembly disclosed in the drawing is particularly intended for mounting within a tubular 5 column such as may be used to support an illuminated tramc signal employing a neon lamp. Thus there is shown in the drawing a tubular transformer case 1 which may be suspended within a tubular column and which supports apanel 2 upon which the interrupter proper is mounted, 60 the panel 2 being suspended below the transformer housing 1.

The panel 2 is preferablyconstructed of insulating material, and has mounted thereon an electromagnet 3 and an oscillatable disc 4. The disc 4 is secured to a horizontal central shaft 5, which is supported at its front and rear ends, respectively, in pivot bearing screws 6 and '7, respectively. Thus the screws 6 and 7 are provided with depressions in their inner ends to receive the pivot ends of the shaft 5 and are threaded into a U-shaped supporting member 8 which is secured to the panel 2; Disc 4 is provided at its periphery with a segment 9 of paramagneticmaterial, such as iron, and with a counterbalance 10 of non-magnetic material, on'the opposite side, for substantially counterbalancing the weight of the paramagnetic material. A weight 11 is also secured to the disc adjacent its periphery for unbalancing the disc and causing it to assume a desired normal position of rest, in which position, of course, the weight 11 is in lowermost position,

In the operation of the interrupter, disc 4 is positively oscillated byenergizing the electromagnet 3 at intervals to periodically attract the paramagnetic element 9, which will hereinafter be referred to as the armature. The electrical circuit for energizing the electromagnet 3 is shown in Fig. 4 and comprises a pair of contacts 12 and 13, respectively, connected in series with the electromagnet 3 and a pair of terminals 14 and 15, respectively, which, in turn, may be connected to an external circuit includinga source of potential (shown as a 110 -volt lighting circuit) and a device to be operated by the interrupted current which is shown in Fig. 4 as a transformer 16, the secondary of which is connected to a neon tube 17.

Referring now to Figs. 1, 2 and 3, the contac 13 comprises a fixed contact anchored to the supporting base 2, and the contact 12 is secured to one end of a lever 18 which is pivotally mounted to oscillate about a pivot 19 secured to the base. The end of lever 18, to which the contact 12 is secured, is relatively short, as shown, and the opposite end extends down in a slanting position in front of the disc 4. Because of the length and weight of the lower end of the lever 18, the latter normally occupies a position in which the contact 12 is forced into contact with the fixed contact 13.

1i flexible connection 20 is provided to make electrical connection between contact 12 and a binding post 21 secured to the panel 2. Binding post 21 is connected by a wire 22 extending back of the panel 2, to the binding post 15.

Disc 4 is provided with a pin 23 projecting forwardly from the face thereof for engagement with the lower end of lever 18 when the disc is oscillated in a counterclockwise direction, to move the lever 18 in a clockwise direction about its pivot 19, and open the contacts 12 and 13. Pin 23, therefore, serves to open the electrical circuit of the electromagnet' 3 and de-energize it as the armature 9 reaches a position opposite the pole piece of the magnet 3, thereby permitting the disc to continue its oscillation, carrying the armature 9 a substantial distance past the pole piece. The limit of movement of the disc 4 in a counterclockwise direction, after the opening of the contacts 12 and 13, is determined by the weight of the balancing member 11 or by a-springstop member 24 extended up in front of the disc, which stop member intercepts a pin 27 projecting from the disc if the latter moves sufiiciently far. After reaching the limit of its movement in a counterclockwise direction, the disc reverses its movement because of the weight of the balancing member 11 and the armature 9 moves back past the pole of the electromagnet. However, if no stop means were provided to prevent it, the contacts 12 and 13 would again close as soon as the pin 23 moves out of contact with the lower end of lever 18 and the direction of oscillation of the disc would be immediately reversed by the attracrotation of the disc 4 it just clears the upper end,

of spring 25. However, when the disc 4 has moved sufliciently far in a counterclockwise direction to bring the pin 27 adjacent the lower end of spring 25, the pin 23 has contacted the lever 18 and has moved the latter, together with the spring 25, outwardly so that the lower end of the spring 25 barely strikes the pin 27 and is deflected inwardly thereby, to permit passage of the spring past the pin. Thereafter, when the disc reverses its direction of oscillation and moves back in a clock wise direction, the pin 2'7 intercepts the inner side of the lower end of spring 25 (Fig. 3) and moves spring 25 and lever 18 outwardly, the pin 27 sliding along the inner surface of spring 25 as the disc rotates. Pin 27 therefore maintains the spring 25 and the lower end of lever 18 in such a position that the contact 12 is maintained out of contact with the fixed contact 13 until the continued rotation of the disc 4 in a-clockwisedirection carries the pin 27 past the upper end of spring 25. Spring 25 and lever.18 are thereupon released to fall into their lowermost normal position of rest, in which the contacts 12 and 13 are closed to energize the electromagnet 3. By this time, however, the disc 4 has substantially completed its oscillation in a clockwise direction, in which the armature 9. is in the position shown in Fig. 1.

'From the foregoing description, it will be apparent that upon the initial closure of the external energizing circuit, the armature 9 is attracted by the electromagnet, thereby imparting an impulse to the disc 4 to rotate the latter in a counterclockwise direction, this impulse continuing and the disc being accelerated until the armature 9 is in a position opposite the pole piece of the electromagnet, when the pin 23 strikes the lower end of lever 18 and opens the contacts 12 and 13, thereby opening the circuit and de-energizing the electromagnet. The disc then continues to rotate in a counterclockwise direction by virtue of its own inertia until its movement is stopped either by the weight of the balancing member 11, or by the pin 27 striking the spring stop member 24. It thereafter reverses its direction of oscillation and accelerates in the opposite direction because of the weight of the member 11, which tends to return to'its lowermost position. Since the initialcounterclockwise movement of the disc carried the pin 27 past the lower end of spring 25, the latter deflecting to permit the pin 27 to pass, when the disc reverses, and the pin 27 moves back, it intercepts the end of spring 25 and lifts the latter, together with the lower end of lever 18, to prevent the contacts 12 and 13 closing until the disc reaches its normal position of rest (the position shown in Fig. 1) when the pin 27 leaves the upper end of spring 25 and permits the lower end of lever 18 to drop and close the contacts 12 and 13. This energizes the electromagnet 3 which again attracts the armature 9 andrepeats the cycle of operation just described.

Since the electromagnet 3 is energized immediately upon closure of the contacts 12 and 13, the armature 9 is immediately attracted by the magnet and swings the disc to bring pin 23 against lever 18 and reopen the contacts. Therefore, the time during which the contacts 12 and 13 are closed is relatively small as compared to the total time required for a complete oscillation of the disc. This makes the device economical of current.

The operation of oscillation of the disc 4, and therefore the time interval between consecutive closures, may be adjusted between wide limits by varying the weights of the armature 9 and the counterbalance 10, and of the member 11. Thus increasing the weights of the armature 9 and the counterbalance 10 decreases the speed of oscillation, whereas increasing the weight of the-member 11 decreases the period of oscillation.

A condenser 28 is preferably bridged across the binding posts '14 and 15 to reduce sparking at the contacts 12 and 13 resulting from inductive reactance in the external circuit to which the interrupter is connected.

Having fully described the preferred embodiment of this invention, it is to be understood that I do not limit myself to the exact construction herein set forth, which may obviously be varied in detail without departing from the spirit of this invention, but only as set forth in the appended claims.

I claim:

1; An electrical interrupter comprising an oscillatable member, an electromagnet adjacent the path of oscillation of said member for urging said member in one direction during a substantial portion of the travel of said member, a pair of contacts for opening and closing the energizing circuit of said electromagnet, a movable arm for opening said contacts in response to movement in one direction and closing them in response to movement in the other direction, said arm normally seeking a position in which said contacts are closed, means movable in response nosaoss to movement of said oscillatable member for shifting said movable arm to open said contacts during a predetermined portion of the movement of said oscillatable member in one direction at least, and other means for preventing return movement of said arm into position to close said contacts during an additional portion of the movement of said member when the latter is moving in one direction only.

2. In an electrical interrupter, an oscillatable member comprising an armature adapted to oscillate in a predetermined path between first and second end positions, an electromagnet positioned adjacent the path of movement of said armature intermediate the ends of said path, means for urging said armature toward said first end position, a pair of contacts for opening and closing the energizing circuit for said electromagnet, a movablearm for closing and .opening said contacts, said arm normally seeking a position in which said contacts are closed, said oscillatable member comprising means for impinging against and shifting said arm to open said contacts while said armature is in that portion oi? its path extending from a point adjacent said electromagnet to its second end position, and additional means operable only during movement of .said armature from said second to said first end position for preventing contact-closing movement of said arm until said armature has substantially reached its first end position.

3. An electrical interrupter as described in claim 2, in which said last means comprises a fiat spring secured at one end to said arm, and a cooperating pin on the oscillatable member, said one end of said spring member being nearer the first end of said path than is the free end of the spring and being out of the path of movement of said pin and the free end extending across the path of movement whereby the pin passes on one side of the spring during movement of the oscillatable member from said first to said second end positions, deflecting the free end of the spring as it passes it, but engages the opposite face of the free end of the spring on its return movement,

and delays contact-closing movement of said arm until the pin has moved the'length of the spring.

'4. An electrical interrupter comprising a disc pivoted to rotate about its axis in a vertical plane, an electromagnet mounted adjacent the periphcry of said disc, an armature comprising a segment of paramagnetic material secured to said disc for movement with said disc past said electromagnet, means for completing a circuit to said electromagnet comprising a fixed contact and a movable contact, an arm extending slantingly downward across the face of said disc and pivoted for movement in a plane parallel to said disc, said movable contact being mounted upon said arm and being normally maintained against said fixed contact by the weight of said arm, a pin extending from the face of said disc for engaging with and lifting said arm to separate said contacts when said armature oscillates past said eiectromagnet in one direction and maintaining them separated while the armature is completing its movement in that direction and returning to the electromagnet, and a resilient arm attached to said arm and extending approximately parallel thereto, and a second pin extending from the face of said disc and so positioned on said disc as to intercept said resilient arm and maintain said arm in raised position following the release of said arm by said first mentioned pin during return movement of said disc, said pin deflecting said resilient arm inwardly with respect to said first mentioned arm and slippin past the end thereof during the movement of said disc in said one direction.

5. An electrical interrupter comprising an oscillatable member, an electromagnet adjacent the path of oscillation of said member for urging said member in one direction during a substantial portion of the travel of said member, a pair of contacts for opening and closing the energizing circuit of said electromagnet, movable contactaetuating means for opening said contacts in response to movement of said means in one direction and closing them in response to movement of said means inthe other direction, said means normally seeking a position in which said contacts are closed, means movable in response to movement of said oscillatable member for shifting said contact-actuating means to open said contacts during a predetermined portion of the movement of said oscillatable member in one direction at least, said contact-actuating means comprising a resilient strip, and a projection on said oscillatabie member positioned to pass adjacent one side of the said strip and deflect and slip by the free end of said strip during movement of said oscillatable member in said one direction and to intercept the other side of said strip and prevent movement 'of said contact-actuating means into position to 'ciow said contacts during a portion 01 the return movement only of said oscillatable member.

. ELMER E. FREE.

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