US2889553A

US2889553A - Lobing switch

Info

Publication number: US2889553A
Application number: US562391A
Authority: US
Inventors: Carl F Schunemann
Original assignee: Thompson Ramo Wooldridge Inc
Current assignee: Northrop Grumman Space and Mission Systems Corp
Priority date: 1956-01-31
Filing date: 1956-01-31
Publication date: 1959-06-02
Anticipated expiration: 1976-06-02

Description

June 2, 1959 c. F. SCHUNEMANN 2,889,553

LOBING swrrcu Filed Jan. 61, 1956 5 Sheets-Sheet l .June 2, 1959 c. F. SCHUNEMANN 2,889,553

LOBING SWITCH Y Filed Jan. 51, 1956 a Sheets-Sheet a v Fay-5 1 "W V we ELY-E ZZZ-U? Y Carl F Sc/zizzemazm I nited LOBING SWITCH Carl F. Schunemann, Euclid, Ohio, assignor to Thompson Ramo Wooldridge, Inc., a corporation of Ohio This invention relates to a lobing switch and more particularly to a switch for an antenna lobing system or the like in which a movable contact is sequentially connected to a plurality of stationary contacts.

In order to determine the direction from which a radio signal is received, a directional antenna array or a loop antenna may be rotated through 360 in azimuth with the direction being indicated by plotting the strength of the received signal as a function of the angle of rotation. However, in certain frequency ranges, such as from 10 to 60 megacycles, a directional antenna array may be too cumbersome for convenient rotation and yet the frequency may be too high for efiicient operation of a loop antenna. In such a case, a number of directional antenna elements may be equally spaced about a vertical axis and sequentially connected to a receiver through a switch including one or more movable contacts sequentially engaged with stationary contacts respectively connected to the antenna elements.

In such an arrangement, one desirable feature is that the elapsed time in switching from one contact to the next should be as small as possible and it is also desirable that the coupling between the stationary contacts be as small as possible to minimize cross-talk. It is further desirable, of course, that the switch be simple, compact, efiicient and reliable in operation and constructed of parts which are readily and economically manufactured and assembled. It is therefore the object of this invention to provide a switch having these desirable features.

According to this invention, a movable contact is driven in such a manner that its speed of movement is relatively low while it is in engagement with each stationary contact and relatively high when moving between the stationary contacts. With this arrangement, the elapsed time in switching between contacts is minimized and at the same time the stationary contacts may be spaced apart a substantial distance to minimize coupling therebetween.

Any variable speed drive arrangement could be used but preferably, a support element is arranged to be driven in such a manner that a point thereof moves in a path generally parallel to an imaginary line interconnecting adjacent stationary contacts, and means are provided resiliently urging the movable contact away from such point toward a position beyond such imaginary line. With this simple arrangement, the support element may be driven at a constant speed and the resilient means stores up energy while the movable contact engages a stationary contact with the stored energy being released to snap the movable contact into engagement with the next stationary contact. In addition, the pressure exerted between the contacts and the wiping action obtained between contacts minimizes contact resistance and insures reliable switch operation.

The support element is preferably rotatable with the stationary contacts arranged in arcuately spaced arrangement about the axis of rotation of the support element, and the movable contact is preferably carried by an arm s Patent 2 of resilient material so as to provide a very simple and yet efficient and reliable construction.

This invention thus provides a switch which is very simple in construction and yet highly efiicient and reliable in operation. The switch has general application but is particularly advantageous in an antenna lobing system because of the fact that the elapsed time in switching between contacts is minimized while the contacts may be spaced apart a substantial distance to minimize coupling therebetween.

This invention contemplates other objects, features and advantages which will become more fully apparent from the following detailed description taken in conjunction with the accompanying drawings which illustrate a preferred embodiment and in which:

Figure 1 is a side elevational view of an antenna assembly incorporating a lobing switch constructed according to the principles of this invention;

Figure 2 is an elevational sectional view through the switch of the assembly of Figure 1;

Figures 3, 4 and 5 are sectional views respectively taken substantially along lines III-III, IVIV and V-V of Figure 2; and

Figures 6 and 7 are sectional views respectively taken substantially along lines VI-VI and VII-VII of Figure 5.

Reference numeral 10 generally designates an antenna assembly in which a lobing switch unit 11 constructed according to this invention is used to sequentially connect the input of a receiver to a plurality of antenna elements 12. The switch unit 11 is supported at the upper end of a mast 13.

Each of the antenna elements 12 is secured to a hooked end portion 15 of a conductor 16 embedded in a support ring 17 of insulating material such as plastic with the conductors 16 extending radially in angularly spaced relation like the spokes of a wheel. The inner end of each conductor 16 is soldered to a lug 18. Screws 19 extend through the lugs 18 and through tubes or sleeves 21, with the ends of the screws 19 being threaded into a support ring 22 of insulating material which is supported on a flange ring 23 secured in assembly with the ring 17.

The tubes or sleeves 21 form stationary contacts and are disposed in spaced relation in a circle about the axis of the shaft of an electric drive motor 24 supported on the flange ring 23.

The motor shaft 25 is coupled by a pin 26 to one end of a coupling shaft 27 the other end of which is coupled to the shaft 28 of a synchro torque transmitter 29 which generates a signal for the remote indication of the angular position of the shaft 28 and elements coupled thereto. The transmitter 29 is secured within a base 30 of invetted cup-shaped configuration which is slipped on the end of the mast 13. The ring 17 is supported from the base 30 through a bearing plate member 31 of inverted cup-shaped configuration which is also used to support a ball bearing assembly 32 for the coupling shaft 27.

A collar 33 is secured on the coupling shaft 27 and carries a ring 34 of insulating material. As shown in Figures 3 and 4, the ring 34 has a pair of

blocks

35 and 36 secured to the upper face thereof with outwardly projecting

arms

37 and 38 being secured at their inner ends to the

blocks

35 and 36 and with contacts 39 and 40 secured to the outer end portions of the

arms

37 and 38.

The

arms

37 and 38 are of a resilient conductive material, preferably beryllium copper, and are of such length that in the unstressed condition thereof, the contacts 39 and 40 project outwardly beyond an imaginary circle at the inner edges of the stationary contacts defined by the tubes 21. With counter-clockwise rotation of the ring 34 and

blocks

35 and 36 secured thereto (as viewed in 3. Figures 3 and 4), the contacts 39 and 40 will engage a pair of the contacttubes" 21. Witlifurtlier'counteFclo'clG wise rotation, the arms 37 will be resiliently bent back ina clockwise direction and thecontacts 39and v40 will slide radiallyinwardly ionf-gthe contact'tubes'lll'i' When the arms 37 -and 38are bentto suchian extentthat' the contacts 39 'and40lare inside the contact tubes .21; the arms will be released and the resiliencyjthere'of will snap them forwardly toward the nextpajriof contact tubes.

Preferably, the position and length. of the

arms

37 and 38 is such. relative to the position and spacingof the tubes 21 that when the contacts 39and 40' teria'lmounted on the underside; jofitl'ie insulating ring 342 and engaged by brushesAS and 44 mounted in slevesAS and 46 andurged' into pressure: engagement with the'

slip rings

41 and 42 by coiledcompressionf springs; 47 and 48*within' the sleeves 45 and 46whiehare pressediinto insnlator49 'afiixed to thebearing'platefllij The'sl'eeve 45 is formed to provide a first terminal post 50'projectingithrough" the hearingtplatei 31' and the sleeve" 46 is connected through a wire51' to a secon'd'terminal'post 52 also extending through the bearing plate 31. The

terminal posts 50 and 52 are'cormected through wires 53"and' 54 to'terminal posts 55 and '56 insulatingly supported in'the wall of th'e'bearingplat'e 31, the postsSS and'SG-being arranged for connectionithrough a' suitable transmissionline"tothennpntterminals of a receiver;

The conductors of a cable 57 connected tofthemotor' 24" and a cable 58"connected'to'the-transrnitter 29a're connected to a-jack 59 supportedin the wall of the 'hearing plate member 31, and'aplug insertedin'th'ejack 59'may beconnected to a remote unitnot shown' including ,a position indicator'actuated by-the signal fiom thetransmitter 29 and' also 4 including a power supply forth'e motor 24'. A capacitor 60in circuit with the-motor 24may be disposed withinthe bearing plat'ej member *31: 1

It willbe noted thatin theillustrated antenna assembly,

there are eighteen elements at" equal' spacings of*20 and theterminals 55- and 56 whichmay beconnected to*the receiver input are at any given instant: connected to a pair of the antenna elements spaced 40 apart so" that the antenna is thus a sloping inverted V with an included angle"of4(); Such an antenna may have highly directional characteristics, and by plotting the receiver response with respect to rotation of the switch assembly, the direction from which a received signal emanates can be accurately determined, It will be apparent that the antenna elements may becotany desired length and the unit 11 may be of much smaller size relative to the length of the antenna; elements thanis the case with the assembly illustrated in Figure 1.

Thisinvention: thus provides a switch which is very simple in construction and yet highly efficient andreliable in operation. Thezswitchhas generalapplication'rbut is particularly advantageous in an antenna lobing system because of the fact that the elapsed time in switching between contacts is at a minimum while the contacts may be spaced apart a substantial distance to minimize coupling Itwill be understood that modifications and variations may b'ej; efiected without departing from the spirit .and-

scope of'the novel concepts of the present'invention.

I claim as myinvention.

Iniarr antenna lobing system; a support ring; of insulatingv'material, 8.".Pll1lfilll'Y of angularly spaced radially extending'con'ductors in said support, ring, a plurality of antenna elements 'connectedto theouten'ends ofsaidcona ductors' toproject therefrom in radial-planes, aplilrality' of stationary contactsconnectedto theinner ends ofsaid conductors and arranged in aicirclein' equi angularly' spacedrelatiowabout the axis of said ring; a contact" support element rotatableabout saidaxis, arrelectric drive motor' for effecting continuous rotation" of' said support element, a pair of resilient leaf springelements'on said contacts to be simultaneously snapped into engagement with the next' pair of saidstatibnary' contacts; and slip ringme'ans *onsaid support element connecting said pair of spring contact elements to a utilization circuit.-

References-Cited in thefile of this patent UNITED" STATES PATENTS 1165,48? Huggins July ll, 1939 2,602,892. Koch t July 8, 1952