US2680163A - Multiplexing switch - Google Patents

Description

June l, 1954 c. W. BEssERER, JR 2,680,163'

MULTIPLEXING SWITCH Filed June l1, 1952 IIIIIIII A r roms vs Patented June 1, 1954 MULTIPLEXING SWITCH Carl W. Besserer, Jr.,

Silver Spring, Md., assigner to the United States of America as represented by the Secretary of the Navy Application June 11, 1952, Serial No. 292,868

2 Claims. l

The present invention relates generally to switching devices and more particularly to an improved multiplexing switch for use on a multiple subcarrier telemetering system` The increased use of telemetering in the eX- perimentation and development of remotely controlled aircraft has brought about an ever increasing demand for systems having greater intelligence carrying capacities. One of the factors limiting the intelligence carrying capacity of a telemetering system is the ability of the switching apparatus of the system to handle increased traiiic requirements. The purpose of a multiplexing switch is to alternately apply a plurality of subcarrier signals, which are indications of the forces desired to be ascertained, to the modulator unit of a radio frequency transmitter rapidly and in sequential order. Due to the limitations of known switches, such as the speed with which switching can be attained, and f the generation of noise due to chattering, etc., the number of subcarrier to signal channels usable with a single transmitter has been unduly restricted.

It is therefore one object of the present invention to provide a multiplexing switch which is capable of switching at very high speeds.

Another object of the invention is to provide a high speed multiplexing switch wherein the generation of noise within the switch is greatly reduced.

Other objects and many of the attendant aclvantages of this invention will be appreciated readily as the same becomes understood by reference to the following detailed description, when considered in connection with the accompanying drawings, wherein;

Fig. 1 is an axial section of the switch, partly in elevation;

Fig. 2 is an end elevation of the switch.

Referring now to Fig. 1, the multiplexing switch comprises a cylindrical casing II having teeth I2 projecting from its inner circumferential surface so as to form an annular internal gear [2a.

A plurality of pairs of terminals I3 project through the casing II at spaced intervals about the periphery of said casing and terminate in companion contacts I4 positioned in the grooves between the teeth I2 of the gear I2a. As best seen in Fig. l, the terminals of each pair are in parallel spaced relation. These terminals I3 are secured to the casing by nuts I5.

Attached to the casing II, as by screws I6, and supporting a cylindrical housing Il, is a circular plate I8 formed with an axial opening I9. A small drive motor 2I including a drive shaft 22 is supported within the housing I8, and has its driveshaft 22 projecting through the opening I9 and axially into the casing II. Fastened to the driveshaft 22 by a locking bolt 23 and extending radially from said driveshaft is a U- shaped bracket which denes a rotor 2li for the switch. The bracket which deiines the rotor 2t includes legs 25 connected by a bight 26, the free ends of said legs being slotted at 27 to receive a trunnion 28 and an insulating sleeve 3B about said trunnion.

Rotatably mounted on the trunnion 23 is a star-shaped contact element 29 made of conductive material and having cogs 3| which mesh with the teeth I2 of the gear I 2a to bridge a companion pair of contacts of the terminals I3. rlwo wire springs 32 are formed with looped central portions 33 which encircle the ends ci the trunnion, and arms 34 bowed outwardly from each other and terminating in hooks 35, which are engageable in apertures 36 in the rotor 2t. Retaining rings 3l cooperate with annular grooves 38 formed in each end of the trunnion 23 to hold said trunnion, and the springs 32 in their intended positions.

In operation, each pair of terminals I3 or as many pairs as there are circuits to serve, is electrically connected into its respective circuit. Upon the motor 2I being energized, the starshaped element 26 rolls in a planetary path about the inner circumference of the casing II. The switching action is accomplished by the cogs 3l which mesh with the teeth I2 of the gear I2a and sequentially short-circuit the contacts of each pair of terminals I3.

The springs 32, because of the bowed shape of their arms, urge the cogs 3I of the star shaped gear 2S outwardly to rmly engage the teeth I2 of the casing II and thereby prevent chattering.

A switch of the type described has the unusual capacity of consecutively serving a great many circuits in a short interval of time. Notwithstanding the high speed operation of the switch, chattering and other noises which are characteristic of the prior high speed switches are eiTectively reduced.

Obviously many other embodiments other than that shown and described are possible without digressing from the teachings of the invention defined in the appended claims. For example, the cylindrical casing I I including the gear teeth I2 may be extended to accommodate ranks of terminals in annular series each rank comprising a plurality of pairs of terminals I3 and their companion contacts I4. A bank of rotor assemblies then may be arranged on a common driveshaft to accomplish the switching action. Therefore, the foregoing detailed description is to be construed only as illustrative of this invention and not as limiting upon the appended claims.

What is claimed is:

l. A multiplexing switch, comprising, an internal gear, a plurality of electric contact members disposed in the troughs of said gear, said=mem+ bers being insulated romeachother, a driveshaft concentric with said gear, a UI-shaped'rotor, having two legs connected by a bight and a slot formed in the extremity of each leg, said rotor being mounted on said driveshatso that-the legs extend radially from said shaft, a trunnionvsupported in the slots of said rotor, a star-shaped contact element rotatably mounted on .said ,trun- 20 nion and insulated'. therefrom, spring means mounted onv said rotor and bearing upon said trunnion to urge said'contact elementinto rm 4 engagement with said gear and said contact members, and means for rotating said shaft.

2. In a multiplexing switch for sequentially closing a plurality of electric circuits, a mounting, a plurality of terminals arranged in an annularly spaced series on the mounting, and contact meansengageable Withsaid terminals, said contactrneans. including adriveshaft, a U-shaped rotor on the driveshaft having a slot orxned in the extremity of each leg of said rotor, a trunnion supported in the slots of the legs, a contact elementl on the trunnion, and spring means tensionedbetwcen-the trunnion and the legs of the rotor. for' urgingthe contact element into selective engagement with said terminals.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 916,649.' Backev Mar. 30, 1909 1,197,537 Parker Sept. 5, 1916 2,399,022: Harkness Apr. 23, 1946

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