US2790039A - Electric multiple switches - Google Patents

Description

April 23, 1957 F.TR1NGAL1 2,790,039

- ELECTRIC MULTIPLE SWITCHES Filed D60. 7, 1953 2 Shee'ts-Sheet l Apnl 23, 1957 F. TRINGALI ELECTRIC MULTIPLE SWITCHES 2 Sheets-Sheet 2 Filed Dec. 7, 1953 ELECTRIC MULTIPLE SWITCHES Francesco Tringali, Augusta, Italy Y Application December 7,1953, Serial No. 396,383

Claims priority, application Italy December 20, 1952 s caaims. (c1. 20o- 9) Multiple switchesV normally used in radio apparatus (sliding contact switches) have some drawbacks due to their mechanical construction, which after a shorter or longer period of operation result in anincrease of the electric resistance between the contacts, which might cause the total interruption of the current, especially if the current, flowing through the circuitincluding said contacts, is of a very high frequency (short waves).

Other types of similar switches, the Vdrum switches, though being more reliable in operation, have the drawback of being cumbersome and expensive, and therefore are hardly or. not at all employable in apparatus Where the space is limited or Where the economic factor is prevailing.

An object of Vthis invention is to eliminate the mentioned disadvantages, by providing a switch of a type absolutely free from Wrong contacts, having limited dimensions and being economical enough to substitute with advantage for the switches with sliding contacts.

This is possible because of a new arrangement and shape of the contacts and of `a characteristic arrangement and shape of the contactors.

In the annexed drawings an embodiment of a multiple commutator in accordance with this invention is shown by way of example.

Fig. l is a plan View of a stator member included in a switch embodying the present invention;

Fig. 2 is a sectional view taken along the line II-II of Fig. l;

Fig. 3 is an electrical diagram showing the Various commutations obtainable with the switch illustrated in Figs. 1 and 2;

Fig. 4 is a plan View similar to Fig. l,V but showing another embodiment of the invention;

Fig. 5 is a sectional view taken along the line V-V of Fig. 4;

Fig. 6 is an electrical diagram showing the various commutations obtainable with the switch of Figs. 4 and 5.

Fig. 7 is a plan view of a rotor member to be used inV connection with either of the stator members illustrated in Figs. l and 4, respectively;

Fig. 8 is a side elevational view of the rotor member of Fig. 7;

Fig. 9 is a sectional view taken along the line lX-IX of Fig. 7;

Fig. l() is a side elevational view of a switch assembly made up'of a plurality of the rotor and stator members illustrated in Figs. l to 9, inclusive;

Fig. 11 is a fragmentary side' elevational view of a modied form of rotor contactor; and

Fig. l2 is a side elevational view, partly broken awayV and in section, of the rotor contactor of Fig. l1.

Referring to the drawings, Figs. l, 2 and 3 illustrate an embodiment of the invention, wherein, a small plate `1 ofinsulating material, having the shape of a circularV crown, has lixed thereon, radially extending metallic contacts 2 arranged with equal angular distances therebetween and with their ends 3 shaped in angular form to nited States Patent t tact crowns of the described type which `are spaced apart and, form a pair of elements of the stator, and to secure together several of such pairs for forming the complete stator of the commutator. Y

The two small contact plates of each pair can be made in the form as above described, so as to realize the commutation according to the electric diagram of Fig-` ure 3; alternatively, the contacts of one of thevsmall plates of each element may have another shape, as shown in Figs. 4 and 5, in order to obtain the commutation ac-v cording to the electric diagram of Figure 6; or otherwise the two crowns forming each stator element may be made, if this should be practically convenient, by a single crown of insulating material having a suitable thickness, on which the two Contact sets are fixed or incorporated Salong the opposed faces of the crown, with each set of c it forms a couple.

It is evident that the number of the sectors determines the number of different circuits controllable by the switch, whereas `the number of the angular cavities Vof each sector determines the number of the positions or commutations of the switch.

It is also eviden-t that, by suitably joining several elements (pairs) the number of the commutable ways, as Well as the number of the positions, can be increased at will, as shown on Figure 10.

Figs. 7, 8 and 9 show a rotor element of the switch, consisting of a cylindrical body of insulating material 11 in which there are radial channels 12, containing cylindrical contacting rollers 13 and pressure springs 14, which press the corresponding rollers in a radially outward direction.

The rotor element 11 is xed by means of suitable members in a concentric position in respect to the stator element and can turn with its axle 15, on which it is xed, within the crowns of the stator element, as shown on Figure 10.

A rotatory movement imparted to the axle 15, produces the step-by-step rotational movement of the rotor, which is successively stopped in exact correspondence to the angular cavities (stopping notches) ofthe several con` tacts, owing' to the rollers 13 entering the corresponding notches under the pressure of the springs, so progressively establishing at each snapping one or more contact bridges (according to the numberY of contactors contained in the rotor) between the corresponding contacts of the two small plates of each stator pair. Owing to the radially outward force continuously exerted by the springs on the contacting roller, and owing also to the particular shape ofthe angular notches of the several contacts and to the shape of the contacts, the engagement between the roller 13 and the contacts is always reliable, even after a an,... ...d

long time of use, with an electric contact resistance practically neglectable.

Obviously, the number of the contactors of each rotor element is determined by the number of the sectors or ways of the Vstator element, and it is possible to couple on the same rotation axle several identical rotor elements in correspondenceof a same number of stator elements, also identical, in order to increase the number of the ways and of the positions of the switch according to Figure 10.r i

According to a further form of realization, shown on Figs. 11 and 12, the contactors can have the shape of rectangular metallic bodies 16 having al suitable thickness and round outside edges yfor engagementwith the contacts of the stator 17, and which are held in radial guides 18 on the rotor and forced in a centrifugal direction against the surrounding contacts of Vthe rotor by means of springs 19.

yOf course, the shape and the particulars of construction can be modified in accordance with the practical requirements, without departing from the scope of the invention.

Iclaim:

1. A multiple switch for the commutation of radio frequency electrical currents, said switch compn'sing at least one stator member and a coaxial rotor member associated with each stator member, said stator member including at least two thin annular members of insulating material in axially Ispaced apart relation to provide an air gap therebetween, a plurality of blade contacts fixed on each of said annular members, each of said blade contacts having at least one radially inward opening V-shaped notch `axially aligned with a corresponding 2. A multiple switch for the commutation of radio frequency electrical currents as in' claim 1; wherein each stator further includes insulating spacing members hold- 'ing said annularr members in axially spaced relation.

3. A multiple switch' for the commutation of radio frequency electrical currents as in claim 1; wherein each of said blade contacts is a thin elongated conducting member arranged radially and having a shtail-shaped radially inward end dening said V-shaped notch.

References Cited inthe tile of this patent UNITED STATES PATENTS 1,853,506 carter Apr. 12, 1932 2,015,399 Grothe Sept. 24, 1935 2,201,881 Bryant et al. May 21, 1940 2,418,616 Batcheller Apr. 8, 1947 FOREIGN PATENTS 605,385 France Feb. 16, 1926 804,247 France July 27, 1936 571,395 Great Britain Aug. 22, 1945 611,133

Great Britain Oct. 26, 1948

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