US2639345A

US2639345A - Electric control device

Info

Publication number: US2639345A
Authority: US
Inventors: Sitzer Philip
Original assignee: Tung Sol Electric Inc
Current assignee: Tung Sol Electric Inc
Priority date: 1949-05-18
Filing date: 1949-05-18
Publication date: 1953-05-19
Anticipated expiration: 1970-05-19

Description

May 19, 1953 P. SITZER 2,639,345

ELECTRIC CONTROL DEVICE Filgd May 18, 1949 /4 will 1H INVENTOR Pym/P 51725;?

ATTORNEYS Patented May 19, 1953 ELECTRIC CONTROL DEVICE Philip Sitzer, Irvington, N. J., assignor to Tung- Sol Electric Inc., Newark,

of Delaware N. J a corporation Application May 18, 1949, Serial No. 93,909 I This invention relates to electric control devices.

In one aspect of the invention it relates to electric circuit control devices of the combined electromagnetic and thermal type disclosed in United States Schmidinger Patents Nos. 2,103,276 and 2,103,277, for Flasher Device, issued December 28, 1937.

One object of the invention is a new and improved electric control device of the above character in which the life of the switch contacts is materially increased, and in which there is a material reduction in manufacturing costs.

Another object of the invention is a new and improved relay structure for flasher andother purposes having more uniform operating characteristics over long periods of time, and improved uniformity in operation of switches produced in quantity.

Another object of the invention is a new and improved electromagnetic control device enabling a wide degree of control to be exercised over the operating characteristics in production, and which will retain such characteristics over relatively long periods of time.

Another object of the invention is to provide means for suppressing objectionable vibratory action on flasher and other similar switches, and especially in switches of the plug-in type.

Another object of the invention is a new and improved thermally-operated flasher.

Still another object is to provide a new and improved electric control device.

These and other objects will become more apparent from the following description and accompanying drawings forming part of this application. In the drawings:

Fig. l is a front elevation of a switch in accordance with the invention, with a portion of the housing removed to expose the operating portions;

Fig. 2 is a side elevation of the embodiment illustrated in Fig. 1;

Fig. 3 is a front elevation of another embodiment of the invention with a portion of the outer housing removed to expose the operating parts thereof; and

Fig. 4 is another embodiment of the invention.

In the manufacture of electric control devices of the above character, considerable difficulty has been experienced, to my knowledge, both in the assembly thereof as well as in the adjustment to obtain devices having substantially uniform operating characteristics. The adjustment of the device was critical and did not in many instances retain the adjusted characteristics when put into service.

With my invention I have been able to overcome these difliculties and produce a very much more stable and easily controlled switch, having 4 Claims. (Cl. 200 -88) substantialy uniform characteristics throughout its life. I have also been able to materially extend the life of the switches, eliminate objectionable vibratory action, and materially reduce the costs of the switch in mass production.

Figs. 1 and 2 of the drawings illustrate one form of a flasher switch embodying my invention. In the figures, l0 denotes the outer casing of the switch which is mounted on a base l2 of insulating material and secured to the casing by a U shaped portion 14 swaged or otherwise formed on the bottom of the casing l0 and engaging the periphery of the insulating base 12.

The switch is provided with an electromagnetic core, I6 having enlarged

end portions

18 and 20, more clearly indicated in Fig. 1, and a relatively narrow central portion 22 about which a coil of wire 24 is formed. The core I6 is held in an upright position within the housing In by means of an L-shaped bracket 2'6 having one leg 28 fastened to the base by a pair of lugs 30 eX- tending from the terminal 32 through suitable openings in the base, and bent inwardly over the leg 28 to clamp it tightly to the base l2. The lugs 30 may also engage suitable recesses in the sides of the leg 28 to provide a more secure and rigid mounting'for the bracket 26'. The upstanding leg 34 of the bracket 26 may be spotwelded or otherwise suitably fastened to the lower part 2|] of the core to hold it in the upright position.

Formed integrally with the L-shaped bracket 25 is a lug 36 ektendingoutwardly and inclined upwardly relativeto 'the base. This lug is provided with an opening '38 for the purpose of holding one end of an expansible-contractible pull wire. Ml.

- This embodiment of the invention is provided with a single elongated armature 42 bridging the ends [8 and 20 of a core I 6 and terminating in its upper end in an Leshaped or offset portion 44 to which theupper end of the pull wire 40 is attached by'welding or other similar means. To prevent kinking or damaging of the pull wire at the upper end of the armature, the ofiset portion 44 is formed with a rounded part 46 over which the wire passes. The wire 40 is stretched between the offset part of the armature 44 and the bracket to hold the armature in the open position illustrated in Fig. 1.' The lower end of the pull wire is insulated from the bracket 36 by means of a small sphericalbead of glass 48 molded about the having its lower leg 54 welded or otherwise fastened to the vertical edge or surface 53 of a recess or cut-out 56 in the lower core part 20. The upper leg 52 of the spring 50 forms substantially an L with: the transverse portion of the spring, and is welded or otherwise fastened to the. lower end of the armature 42.

With the armature 42 mounted in this manner; it is movable angularly to open and close a pair of

contacts

58 and 58, the latter of which is formed on the armature. Isr: addition; to the"- angular movement, the armature iscalso movable longitudinally under the influence of the pull wire 40 which is mounted at an acute angle to the armature and spaced therefrom so that upon contraction of the pull wire it will exert small. lateral force on the armature tending to open the contacts, and a rather large longitudinal. force in. a downward direction tending to slide the eontaets oneupon theother the opening operation. The contact 5-8 is supported. by an L-shaped bracket member 60 which is formed integrally with. a rectangular washer-shaped member 62 held betweeni-nsulatihg. washers Ti] and 7.0 and clamped tothe: upper section. I'll of the core by meansot a through rivet 12} The bracketmember- M also held in. place by the rivet 12., has an ls shaped lug l o extendilng therefrom, andpasses in a transverse direction inthe rear of. the armature to limit the outward travel thereof.

The electriccircuit controlled by this device may include a source ofelectrical energy and a device, such as an incandescent lamp, as. the load, connected. inseries Withthe terminals 32 and 32' ofthe switch. The switch circuit consists ofthe terminal 32 which is connected by means of the L-shapod brat-fleet. 25 and the-lower core part 2-8 to the armature supporting. member 5%, thence through the armature 42 to

contacts

58 and 58, the coil M tothe-termi-nal 32-. The pull. wire M! is connected at one end tothe: armature 42 and at the other end to the contact 58 by means of a coiled wire 18.

in the operation of the switch, the connection to the load circuit is completed through the pull wire it the ballast wire 18', which are effectively connected across the normally

open contacts

58 and 58. The resistance of the pull wire and ballast 40' and; 18,. respectively,- impedes the flow of current to the load and limits it to a relatively small value, insufficient to operate the load. When the load includes or comprises one or more incandescent. lamps, this current is insufficient to illuminate the lamps, but will, however, heat the pull wire and permit it to expand. The armatore mounting spring; 50 will pull the armature inwardly to close the: contacts and energize the load. At the same time, the cl'ectromagnet coil is is also fully energized and exerts a magnetic pull on the armature to assist in holding the contacts to ether. at this point the pull wire is short sir-suited by reason of the closure 6f the contacts 53 and 5t, whereupon the pull wire starts to cool. During the cooling or the pull wire, contraction takes place, which exerts a continuously increasing force on the armature, a portionof which is the" Outward direction tend ing to open the contacts while the remainingand somewhat larger portion is in the direction of the armature tending to slide the contacts one over the other during the opening operation. This action is accomplished by reason of the new and improved armature mounting which conat the instant of the opening of the contacts, when the pulling force of the pull wire is just able to overcomethe holding force of the electromagnet, there is a collapse oil the magnetic field constituting the primary holding force on the armature.

In Fig. 3, I have illustrated another form of a flasher switch having two armatures. In this form,, B have; also included a new and improved means for overcoming objectionable vibration of the switch, which turther materially improves the operation as well aslengthening its life.

This form of the invention is similar in certainrespects to the embodiment illustrated in Figs. 1 and 2, and therefore like numbers have been usedv tov denote similar parts in. each. embodiment. In each of'the embodiments; the armature mounting bracket. 50 biases the armature to the normally closed. position of the contacts 53' and 5B"; and. particularly good results have been had with. a bracket; formed, of Z-niokel', which. is. a product of the International Nickel Company and consists of approximately 93%. nickel with other alloying elements, although other resilient materials (such as spring steel, tempered coppers. and brassesi may also be used.

To dampen. vibration of the armature. #2, a spring at oftempered' steel or other suitable material. is. welded or. otherwise fastened at one end to. the lug 16 which extends transversely of the armature 42.. The spring. depends upon said lug and. contacts the armature M at a point substantially below the center thereof and tends to bias the armature to the closed position. However, the force exerted by this spring is not sufficient of itself. to close the contacts. 58 and 58 but supplements the biasing. force produced by the Z-shaped armature mounting. bracket 50. The spring mounted. in. this. manner effectively damp'ens the vibration of the relatively rigid armature 42 which is preferably. formed of annealed, cold rolled steel, which can be produced. with. uniform and stable magnetic properties.

As pointed out. above, the embodiment in Fig. 3 includes a second armature 82 which is. fastened to the lower end portion 20 oi the magnet core it by means. of apiece of spring metal 34' which is welded at one to the base of the armature t2. and at the other end to the leit-hand edge of the core part. 2%.. This spring is preterably formed'to: provide no bias either inwardly. or outwardly on the armature- 3'2.. A second spring 3.8 providing; an. outwardbias is. fastened to the base of the armature: and. extends upwardly to contact an outwardly depending lug. 9i termed as an integral part of the bracket M and extending transversely oi? the armature 82. A second lug 92, also formed integrally with the: bracket member M; lie-disposed parallel to. the member 93 and passes behind the armature B2 to limit the outward movement thereof when the magnet: core 24 is de-energized by the opening of the contacts 58 and. 58' associated with the armature so. The contact 8%: is carried and electrically connected to the armature- BQ Z, while the contact 85 is supported by a bracket member 94' insulated from the magnet core it but supported thereby by means of the rivet 12 in substantially the same manner as the lug or bracket member 69 is supported in Fig. 2. The bracket member 94 carrying. the contact 8% is electrically connected by the lead 86 to a downwardly depending lug memher to fastened. to the insulating base l2. The lug Hi0 shown in full view in Fig. 3 supports the l,;-. 1haped bracket member 2:5 in the same manher as described in connection with lug 32 in Fig. 1. Immediately behind the lug I is a second similar lug I02 which is the equivalent of lug 32' in Fig. 1, and has an outstanding lug member 104 to which one end I06 of the coil 24 is attached. Through suitable connections to the lugs 96 and 1023, the contacts and 86 may he used to break. a separate or auxiliary circuit, and the

contacts

58 and 58 maybe used for effecting the flashing operation only, or, if desired, to operate a load in substantially the same manner as described in connection with Fig. 1.

With this new and improved structure for switches or flashers, such as the thermal switch described, it has been found that far greater control can be exercised over the operating characteristics in the production and manufacture of the device, and that a switch, once adjusted to the desired characteristics, will retain them for extended periods of time. Moreover, by reason of the particular method of mounting the armatures, a sidewise welding operation can be eifected in place of vertical and difficult welding operations which were used, to my knowledge, in prior practice. These factors materially reduce the cost of production, and in addition produce greatly improved switches. Moreover, the particular arrangement of the mounting of the armature 42 provides good wiping contact during the opening operation and this, coupled with the snap-action opening effected by the particular arrangement and direction of the forces applied to the armature to open it, greatly improves the life of the contacts; while the suppressor spring 80 greatly reduces objectionable vibration of the armature and produces more stable and uniform operation of the switch as a whole.

In Fig. 4 I have illustrated another embodiment of the invention, having a single armature. This embodiment is similar to the embodiment illustrated in Figs. 1 and 2, and like numerals have been applied to like parts in each of these embodiments. In Fig. 4, however, I have illustrated a bracket member 14' which is of somewhat difierent shape than the bracket illustrated at 14 in Fig. 1, in that it is provided with but a single outstanding lug member 16 partially embracing the armature 42.

What is claimed is:

1. An electric circuit control device having an electromagnet and an armature, comprising an electromagnetic core having a recess at one end with one edge substantially parallel to the armature when in attracted position, a Z-shaped spring having one leg disposed parallel to said edge and secured thereto and its opposite and parallel leg secured flush to one end of said armature, the middle leg of said spring forming an angle of less than 90 with each of the other legs, the depth of said recess and the length of the middle leg of said spring being correlated to bring the supported end of said armature close to the core above the recess therein.

2. A pull wire thermal switch comprising an electromagnet, a pair of contacts, an armature actuated by the magnet and responsive to energization of the magnet to close the contacts, a pull wire having one end attached to and spaced from the free end of the armature and operable upon cooling in opposition to the magnetic pull of the magnet to open the contacts and exert the major component of its force along the length of the armature, means for mounting the other end of said armature for an ular and lonsitu inal movement including a Z-shaped bracket member, said member tending to bias the armature to the closed position, and spring means on said armature engaging a fixed abutment for supplementing the biasing effect of the Z-shaped member.

3. A thermal switch comprising an electromagnet, a pair of armatures associated with said magnet, and a pair of contacts individual to each armature and adapted to be opened and closed by movement of their respective armatures in response to energizing and de-energizing of said eleotromagnet, a thermally responsive pull wire having one of its ends fixedly mounted with respect to said magnet and the other of its ends connected to one of said armatures to open the armature upon contraction of the pull wire against the force of the magnet, means for mounting said one armature including a Z-shaped spring yieldable under the action of the pull wire on said armature to permit angular and longitudinal movement of the armature, said spring biasing the armature to a closed position of its associated contacts, a suppressor spring fixedly supported with respect to the magnet at a point near the free end of said one armature and extending along the length of said armature to contact it at a point near its other end, and biasing the armature to supplement the bias effected by said mounting spring, means for mounting the second armature including a yieldable spring, and a second spring associated with said second armature and adapted to bias it to a normally open position of its associated contacts.

4. In an electric switch, an eiectromagnet, at least one armature responsive to said magnet, mounting means for said armature comprising a Z-shaped spring with the ends of the spring being in spaced alinement and in alinement with the armature, one end of said spring being fixedly mounted and the other end fastened to the armature, said spring biasing the armature toward attracted position, means connected to the other end of said armature for moving the armature away from attracted position against the bias of said spring under certain conditions, and a suppressor spring strip fixedly supported with respect to the electromagnet at a point near the free end of said armature and extending along the length of said armature and contacting it at a point near said mounting means to bias the armature in a direction to supplement the bias effected by said Z-spring.

PHILIP SITZER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 867,211 Riker Sept. 24, 1907 1,185,370 Cook May 30, 1916 1,209,281 Gardner Dec. 19, 1916 1,727,035 Prescott Sept. 3, 1929 1,973,090 Miller Sept. 11, 1934 2,025,235 Gonsett Dec. 24, 1935 2,063,311 Guedon et a1. Dec. 8, 1936 2,075,499 Buch et a1. Mar. 30, 1937 2,103,276 Schmidinger Dec. 28, 1937 2,326,054 Morton et al Aug. 3, 1943 2,418,953 Raitt Apr. 15, 1947 2,463,380 Harris Mar. 1, 1949 FOREIGN PATENTS Number Country Date 526,940 GreatBritoin was"!!! sent. 27. 1940