US2945931A

US2945931A - Switch assembly

Info

Publication number: US2945931A
Application number: US652968A
Authority: US
Inventors: Glenn A Reese
Original assignee: Magnavox Co
Current assignee: Philips North America LLC
Priority date: 1957-04-15
Filing date: 1957-04-15
Publication date: 1960-07-19
Anticipated expiration: 1977-07-19
Also published as: DE1181778B; GB884397A; GB884396A

Description

G. A. REESE SWITCH ASSEMBLY July 19, 1960 2 Sheets-Sheet 1 Filed April 15, 1957 July 19, 1960. G. A. REESE I 2,945,931

SWITCH ASSEMBLY Filed April 15, 1957 2 sheetssheet 2 United States Patent O 2,945,931 swrrcir ASSEMBLY Glenn A. Reese, Canoga lark, Cali-f., Yassigner to The Magnavox Company, Los Angeles, Calif., a corporation of Delaware Filed Apr. 15, 1957, Ser. No. 652,968 "zz Claims. (ci. zoo-9o) The present invention 'relates to a switching assembly which is capable of repeatedly performing a plurality of successive swiching operations at an extremely high rate of speed and of laccomplishing this without the concomitant production of noise or other transient parasitic signals.

The switching assembly of the. invention finds general utility in the electrical and electronic arts. In these arts, the requirement for high speed multiple-type switches frequently occurs. For example, high speed multiple switches nd general utility as channel selectors in many types of present day digital` computers. YIn fact,- the switching asemblies of the type with which the present` in.- vention is concerned finds utility in any application where rapid multiple switching or commutator action is required.

.The high speed switching assembly to be described in f the following specitication uses a plurality of individual switching units. The individual units are `adapted to be operated from one operational state to another by means of `an external magnetic field. Each of the units includes a magnetic armature which is constrained to move from one fixed contact in the particular unit to another for double-throw operations. This movement of the armature is under the control of the external magnetic iield, and this movement is eifectuatedby variations in the iield. In like manner, the armature can be made to make or break with a single fixed contact, for single-throw action, in response to variations in the external magnetic field.

The switching assembly to be described includes a magnetic structure which defines an annular air gap. The individual switching units are positioned in this yair gap. A magnetic yfield is produced in the air gap which rotates with respect to the individual switching units, and .this iield is caused to exhibit radial shifts or variations at different positions around the air gap. As the magnetic eld sweeps past the various switching units, these eld variations periodically actuate the armatures in the units. In this manner, a succession of switching operations is achieved for each rotational cycle of the magnetic iield. The number of these switching operations in each cycle depends, of course, upon the number of individual switching units that are positioned in the air gap. Moreover, these successive switching operations are repeated for each rotational cycle of the magnetic iield.

The speed with' which the successive switching operations of the assembly may be carried out will be appreciated when it is realized that the magnetic iield may be produced by a magnetic structure which may be appropriately coupled to an electric motor for rotation. Therefore, the rotational speed of the magnetic iield can be of a relatively high order. Then, by placing a plurality of individual switching units in the annular air gap between these rings, a large number of successive and repeated individual switching operations can be conveniently carried out. v

A `feature of the invention' is the provision of aswitching assembly of the type described above which is so conj 2,945,931 Patented July 19, 1960 structed that switch-actuating variations in a rotating magnetic field may be precisely located Iand sharply defined. This per-mits theassembly to be designed and constructed so as to provide an exact relationship between the instantaneous angular positions of the rotating magnetic iield and the'correspo'nding actuation of the switching units. This enables accurate timing of the switch actuations to be realized. Such accurate timing is` an essential requirernent in most present day uses of multiple cyclic switches. -Y Another essential requirement that is met by the switching assembly of thepresent invention is that of high speed switching operation without the accompanying production of undesired noisesignals and other extraneous interference. Such unwanted signals are generally due tocontact 'bounce and to unwanted vibrations of the armatures in the individual switching units. The assembly o'if the present invention operates positively toactuate each individual unit without setting up vibrations in the units so that the generation of such unwanted noise as a by-product of the switching action is avoided. Moreover, the structure and operation of the assembly constituting the invention is such that the individual switching units may be conveniently damped, for example, by a hydraulic uid, further to preclude any tendency for the switch armatures to vibrate and create the undesired noise signals.

From -a mechanical aspect, the switching assembly of the invention has the desirable features of relatively low wear, and this results in extremely long and trouble-free operation. Moreoventhe assembly is relatively simple and inexpensive to construct land operate.

In the drawings where are to be considered as merely illustrative of one embodiment of the invention: l

Figure 1` is a side viewjof one constructed embodiment of the switching assembly :of the invention on a somewhat reduced scale, and shows apparatus, including a drive motor for producing a desired rotational motion of a magnetic eld to successively actuate a plurality of individual switching units which are included in the assembly;

Figure 2 is a top plan view of the switching assembly on the same scale as Figure l, and'showing a pair of annular members. which are positioned to 'form `an annular air gap, and lthis viewialso shows a plurality of magnets whichy create a magnetic ux in the air gap controlling the individual switching units ,which extend into the annular air gap at various positions around the assembly;

Figure 3 is a sectional ,view substantially on the line 3-3 of FigurevZ to showthe mounting of magnets which are'usedto create the ux in the annular air gap;

Figure 4 is a view, partly in section and partly in phantom and on an enlarged scale with respect to the views of Figures l and 2, of one of the individual switching units used in the assembly and its relation to a typical one of the magnets shown in Figure 2; and

Figures 5A and 5B are fragmentary top plan views which schematically illustrate the action of an armature in the individual switching unit shown in Figure 4 as the magnetic flux, in the air gap is swept past the armature'such that `the armature is actuated between first and second fixed contacts in the switching unit.

The switching assembly of the illustrated embodiment of the invention includes an electric motor 10 which is supported on an appropriate supporting surface 12 and which is preferably a synchronous motor. The electric motor includes a drive shaft 14. This drive shaft extends upwardly in -a substantially vertical direction, and it is secured to a turntable 16 to `impart rotational motion to the'turntable. The turntable 16 is disposed in a horizontal plane, and it is composed of a non-magnetic material such as, for example, aluminum. The diameter of the turntable may be of the order of 9 inches.

The turntable 16 supports a pair of

annular members

18 and 20. These annular members are supported in spaced, nested uni-planar and concentric relation, and they are also spaced from the turntable 16. A series of blocks composed, for example, of aluminum and designated as 22 are secured to the turntable and to the respective

annular members

18 and 20. These blocks rigidly support the annular members 18 and20 on the turntable 16, with the annular members lying in a plane above the turntable and parallel to the plane of the turntable.

The annular members 18 and 2-0 may be composed of a magnetic material such as, for example, cold rolled steel. These members define an annular air gap 24 between the outer peripheral edge of the member 18' and the inner peripheral edge of the member 20. The member 18, for example, may have-an in-ner diameter of 6.3 inches and an outer diameter of 7.5 inches. The annular member 20, on the other hand, may have an inner diameter of 7.75 inches and an outer diameter of 8.7 inches.

It is evident that when the motor is energized, its drive shaft rotates the turntable 16 which, in turn, causes the

annular members

18 and 20 to rotate.

The annular member 18 has a series of channels 26 formed as notches in its outer peripheral edge. Each of these channels extends axially along the outer peripheral edge of the annular member 18 and each has a predetermined radial depth. These channels are placed 4 56. The units 52 are disposed at selected angular positions about the turntable 16. It will be understood that as many switching units 52 are used as it is desired to have successive switching operations `for each cycle of rotation of the turntable 16 and of the

annular members

18 and 20.

Details of one of the switching units 52 are shown in Figure 4. The unit may contain a tubular outer casing 58 which is preferably composed of a non-magnetic, electrically conductive material such as brass. The unit is supported so that this housing extends vertically down into the annular air gap 24 of Figure 2. An armature 60 is mounted in the casing S8, and this armature may be composed of a magnetic material such assoit iron. The

v to the casing. Since the armature is composed of a magat selected angular positions around the annular member 18.

A plurality of permanent U-shaped magnets, such as the magnet 28 in Figure 3, lare secured to the turntable 1 6 by screws such as the screw 30 in Figure 3. These permanent magnets are positioned to correspond to the angular positions of the channels 26 in the peripheral edge of the annular member 18, and one of the permanent magnets is located at each s uch channel. Each U- shaped magnet 28 has a pair of spaced parallel legs, and these legs extend upwardly from the turntable 16 into respective engagement with the `

annular members

18 and 20. One of the legs represents a south pole, and the other leg represents a north pole. These legs may be secured respectively to the

annular members

18 and 28* by a pair of screws 34.

The permanent magnets 28 are oset radially with respect to the

annular members

18 and 20 so that the leg associated with the annular member is displaced inwardly from that member and projects into the. annular air gap 24. Likewise, the leg 'associated with the annular member 18 engages that member at the base of the corresponding one of the channels 2.6.

The permanent magnets 28 cooperate with the an

nular members

18 and 20 to produce a magnetic liux in the annular `air gap 24. The lines of the resulting mag netic eld extend in a radial direction from the annular member 20 which constitutes the north pole to the annular member 18 which constitutes the south pole.

TheV `fact that the permanent magnets 28 are offset inwardly in the .illustrated manner, `and the provision of the channels 26 in the outer peripheral edge of the annular member 18, create well-deiined and precisely lo.- Ycated shifts or variations in the magnetic flux in the air gap 24 at the regions of the individual channels 26. Therefore, as the turntable 16 and the annular members y18 and 20 with their associated magnets 28 are rotated by the motor 10, the resulting flux in the annular air gap 214 also rotates.

As shown in Figure l, the top of the motor 1t) projects through a stationary supporting table 50, and the turntable 16 land annular rings 18 and 2t) are supported for rotation on the upper side of the table. The table 50 forms a convenient support for a plurality of stationary individual switching units 52 which extend into the annularair gap 24 of Figure 2. Each of the switching units netic material, it is susceptible to extraneousmagnetic fields which enterV through the non-magnetic casing 58, and such fields cause the armature to move in one direci tion or another against the resilience of the wire 62. In the illustrated embodiment, the armature tapers upwardly and has a contact portion 60a at its upper extremity. This contact portion is composed, for example, of 24 carat gold.

The tubular casing 58 may have an inner diameter of the order of .O67 Iinch `and an outer diameter of the order of .083 inch. The resilient wire 62 may, ffor example, -be a piece of piano wire of .010 inch diameter. The armature 69 may have a diameter of .065 inch at ,its base, and its contact portion 60a may have a diameter o' .025 inch and a length of .050 inch.

The switchingunit S2 is supported in the annular ai-r gap 24 by the @bracket 54 in such a position 'that the north pole of each of the U-shaped magnets 28 passes within about .014 inch from the armature as the turni table `16 is rotated. The tubular casing 58 has an upper portion 66 composed, for example, of an electrically conductive non-magnetic material such as brass. A pair of .fixed contacts 68 and '78 are supported in mutually insulated relation in a plastic compound 72 .in that por# tion. These ycontacts extend throughA the `plastic com-` pound and protrude in spaced parallel rela-tion to 'be dis# posed on opposite sides of the armature contact por tion 60a.

Each of the fixed contacts 68 and 78 may be composed of 24 carat gold, and they may have a diameter of, for example, .032 inch. These contacts may extend about 3/32 of Ian inch below the plastic 72, and their contact area may 'be attened to have a width of about .O45 inch. Suitable electrical connections may be made to -each of the fixed contacts 68 and 78 .by appropriate external terminals. Connection to the armature 68 is made -by way of a termin-al 74. The terminal 74 is secured to the casing 66. llts connection with the armature`60 may be traced through the conductive casings 66 and 58 and through the plug 64 and through the Wire 62 to the armature 60.

It is evident, that when the armature 68 is moved under -the influence ofV an external magnetic field, it may make The casing 58 is preferably lled with an hydraulic l fluid to prevent undesired vibration of lthe armature 6i) and to provide suitable damping for the unit. VWhen the switching unit 52 is placedl annular amasar that one of the magnets 28 passes the switch 52 as the `assembly is rotated, the shift or variationin the ilux due to the channel 26 and the oiset arrangement of the magnet 28 causes the armature control portionv 60a to move into engagement with the iixedcontac-tp and out of engagement with the fixed'contact 70.

Therefore, each time a channel 26 and its associated magnet 28 sweeps by one of the switching units as the assembly is rotated, it actuates'that unit lfrom one operating condition to the other. rEach one of the plurality of switching units 52 may be operated anydesired' number of times during each rotation of the turntable 16, as determined by the number of channels 26 and the permanent magnets v28 respectively associated with those channels.

As noted previously, the provision of the channels 26 and of the offset magnets 28 provides precisely located and well-defined shifts or variations in the magnetic ilux in the air gap 24 so that the actuation of the switches can be accurately controlled and timed. Moreover, the actuation of the switches is positive and there is no vibration in the switch armatures. This reduces ext-raneous noise to a minimum and sharply defined switching action is obtained.

The apparatus constituting this invention has certain important advantages in addition to those described previously. yOne advantage results from the 'fact that the apparatus can be disposed in any other plane than the horizontal pl-ane. This advantage is obtained because 'the armature 60 is held against the

contacts

68 and 70 by a force in the order of 50 t-o 100 Gs and a gravitational force of 1 G would have little effect on-such a holding force. i

Another advantage results `from the fact that all leakage iiux lis produced internally in the air gap between the

annular members

18 and 20. This results `from the closed loops provided for the

members

18 and 20. Since relatively little leakage flux can traverse the area outside of the

members

18 and 20, electrical leads andV even magnetically receptive equipment c-an be disposed in the immediate vicinity of the apparatus constituting this invention without having any undesirable signals. induced in such leads and magnetically receptive equipment.

Although this application has been disclosed and illustrated with reference to particular applications, the principles involved are susceptible of numerous other applications which Will be apparent to persons skilled in the art. The invention is, therefore, to be limited only as indicated fby the scope of the appended claims.

' I claim:

l. A switching Iassembly including: means including first and second walls spaced to define a continuous air gap between the walls and having contours to define a displacement in sa-id air gap in at least one position along said walls yand having properties to produce in said air gap a field exhibiting variationsat the position of displacement, means coupled to the first and second walls for producing a magnetic iield in the air gap in accordance with the disposition of the air gap lat successive positions, switching means disposed l-in said air gap and responsive to such variations Iin said field to be actuated from one operating condi-tion to another, and means for producing relative motion between said Walls land said switching means to bring said switching means period- -ically under the inuence of the variations in the fiield.

2. A magnetically controlled switching assembly including: means 'including first and second walls spaced 'to define a continuous ai-r ,gap between the walls and provided with -contours in at least onewall to define a walls and having properties to produce in said gap magnetic flux at successive positionsjalongsaid air Agap inthe direction between .the walls and to produce variations in Ysuch magnetic -ux at the position of displacement and in accordance with such displacement, means coupled magnetically to the first and second walls for producing a magnetic flux in the air gap in accordance with the disposition of the air gap at successive positions, switching means disposed -in said air gap and including an armature repsonsive to suchvariations in the magnetic flux to control the operating condition ofjsaid switching means, and means for producing relative motion between the walls and said switching means to bring said armature periodically under the influence of the variations in the magnetic iiux. i

3. A magnetically controlled switching-assembly including: rotatable means including first and second walls spaced 'from each other in a direction transverse to the plane of rotation to define an air gap extending in the direction of rotation and provided with contours to deline a displacement in the air gap at a particular position and in the transverse direction, means including the firs-t and second walls for producing a magnetic flux across said air gap in accordance with the positioning of the air gap in the transverse direction -to obtain variations in the magnetic flux at the position of displacement of the air gap `and in accordance with such displacement, at least one stationary switching unit disposed in said annular air gap and including an armature constructed at least in part of magnetic material yand responsive to such variations in the magnetic flux to con-trol the voperating condition of said switching unit, and means for rotating said rotatable means to produce relative mo.- tion Ibetween said magnetic flux and said switching unit to bring said armature periodically under the influence of the variations in the magnetic flux.

4. A magnetically controlled switching assembly including: means including first and second walls spaced to define a continuous ai-r gap between t-he walls and having contours in at least one wall to define a displacement in said air gap -in at least one position along said walls Aand in a direction transverse to the walls and having properties to produce in said `air gap magnetic flux extending between the walls to obtain variations in the magnetic flux at the position of displacement and in accordance with such displacement, at least one switching unit -disposed in said air gap, said switching unit including .a resiliently mounted armature and at least one fixed contact engageable by said armature underthe control of such variation in the magneticux, and means for producing relative motion between said walls and said switching unit in a .direction transverse to the displacement in said air gap to bring said armature periodically under the influence of such variations in said magnetic ux.

5. A magnetically controlled switching assembly in cluding: means including-first and second walls spaced to define a continuous yair gap between the walls and provided with contours in at least one wall to define a displacement in said air gap in the direction between the wal-ls and having properties to produce in said air gap magnetic flux at successive positions along said air gap in the direction between the walls and to produce variations in such magnetic liux Iat the position of displacement and in acc-ordance with such displacement, at least one switching unit disposed in said air gap, said switchingu-nit including a housing of non-magnetic material, and said switching unit further including a resiliently mounted armature and at least one fixed contact engageable by said armature under the control of such variations in the magnetic Iflux, a damping fluid included in said housing to inhibit vibrations of said armature, and means for producing relative motion between said |walls and said switching unit in a direction `transverse to the displacement in the lair gap to 'bring'lsaid 7 armature periodically under the influence of said variations in said magnetic flux.

6. A'magnetically controlled switching assembly including: means for defining an air gap and including first and second walls spaced to dcline a continuous air gap between the walls and having contours in at least one wall to define a displacement in said air gap in at least one position along said Walls and in a direction transverse to the walls and lhaving properties to produce in said air gap magnetic iiux extending between the Walls to obtain variations in the magnetic flux at the position of displacement and in accordance with such displacement, at least one switching unit disposed in said air gap, said switching unit including a housing of non-magnetic material and a pair of fixed contacts supported in said housing at mutually spaced positions, said switching unit further including an armature resiliently supported in said housing and having a contact portion ex-tending -between said iixed contacts and further having a magnetic portion responsive to said magnetic liux in said air gap to cause said contact portion to engage one of said fixed contacts and responsive to said variations in Ithe magnetic fiux to cause said contact portion to engage the other of said fixed contacts, a damping liquid included in said housing to inhibit vibrations of said armature, and means for producing relative motion between said walls and said switching unit in a direction transverse to the displacement in said air gap to bring the magnetic portion of said armature periodically under the infiuence of said variations in said magnetic iiux.

7. A magnetically controlled switching assembly including: a pair of annular members supported in concentric relation to define an annular air gap therebetween and provided with contours to produce a displacement in said air gap in at least one position in a direction perpendicular to said annular direction, means associated with said annular members for producing in said annular air gap a magnetic flux exhibiting variations at the position of displacement in said air gap and in accordance with such displacement, at least one switching unit disposed in said annular air gap and including an armature constructed at least in part of magnetic material and responsive to such variations in the magnetic ux to control the operating condition of said switching unit, and means for producing relat-ive motion between said switching unit and said pair of annular members in the annular direction to bring said armature periodically under the influence of the variations in the magnetic flux.

define an annular air gap therebetween, means associated with said annular members for producing in said annular air gap a magnetic flux in a direction substantially perpendicular to the annular direction, means associated lwith said annular members for producingta displacement in said air gap in at least one position and in a direction substantially perpendicular to said annular direction to obtain flux variations at that posi-tion in said air gap in a direction substantially perpendicular to said annular direction and in accordance with the displacement in the air gap, at least one stationary switching unit disposed in said annular air gap and including an armature constructed at least in part of magnetic material and responsive to such variations in the magnetic flux to control the operating condition of said switching unit, and means for rotating said rotatable means to produce relative motion between said switching unit and said pair of annular members to bring said armature periodically under the inuence of the variations in the magnetic flux.

`9.7A magnetically ycontrolled switching assembly including: first and second annular members each composed of magnetic material and the inner diameter of said annular member exceeding the outer diameter of said second annular member, one of said annular members having at least one transverse channel of a selected width and depth formed in a peripheral edge thereof at a selected angular position and extending axially alongv said peripheral edge, rotatable means for supporting said annular members in concentric relation to define an annular air gap therebetween, means associated with said annular members for producing in said annular air gap a. magnetic iiux exhibiting diametrical displacements .at a position corresponding to the angdllar position of said channel, at least one stationary switching unit disposed in said annular air gap and including an armature constructed at least in part of magnetic material and responsive to such displacements in the magnetic flux in said ai-r gap to control the operating condition of said switching unit, and means for rotating said rotatable means to produce relative motion between said switching unit and said pair of annular members to 4bring said armature periodically under the iniiuence of said displacements in said magnetic flux,

l0. A magnetically controlled switching assembly including: first and second annular members each composed 0f magnetic material and the inner diameter of said lfirst annular member exceeding the outer diameter of said second annular member, one of said annular members having la plurality of transverse channels each of a selected width and depth formed in a peripheral edge thereof and at selected angular positions and each such channel extending axially alo-ng such peripheral edge, rotatable means for Isupporting said annular members in mutually fixed concentric relation to define an annular air gap therebetween, means associated with said annular members for producing a magnetic iiux in said yair gap and including portions extending radially into said air gap lat respective angular positions corre` sponding to said `angular positions of said channels and cooperating with said channels to produce diametrical displacements in said magnetic flux, at least one stationary switching unit disposed in said air gap and including an armature constructed .at least in part of magnetic material and responsive to such displacements in the magnetic iiux to control the operating condition of said switching unit, and means for rotating said rotatable means to produce relative motion between said switching unit a-nd said pair of annular members to bring said 'armature periodically under the influence of said dis- 'placements in said magnetic liux.

1l. A magnetically controlled switching assembly including: first and second annular members each composed of magnetic material and the inner diameter of said first annular member exceeding the outer diameter of said second annular member, Vone of said annular members having a plurality of transverse channels each of a selected width and depth formed in a peripheral edge thereof at `selected angular positions and each such channel extending axially along such peripheral edge, a turntable composed of non-magnetic material supporting said annular members in mutually fixed concentric relation to define an annular air gap therebetween, said annular members being so supported in a plane spaced from the plane of said turntable, electric motor means coupled to said turntable Ifor imparting rotational motion to said turntable and to said annular members, means associated with said annular members for producing a magnetic ilux in said annular air gap and including portions extending radially into said air gap at respective angular positions corresponding to said angular positions of said channels and cooperating with said channels to produce radial displacements in said magnetic flux, atleast one stationary switching unit vdisposed in said annular air gap land including an armature constructed at least in part of magnetic material and responsive to such displacements in the magnetic flux to control the operating condition of said switching unit, and means for rotating said rotatable means to produce relative motion between said switching unit and said pair of annular members to bring said armature periodically under the inliuence of said displacements in said magnetic flux.

12. A magnetically controlled switching assembly including: first and second annular members each composed of magnetic material and the inner diameter of said first annular member exceeding the outer diameter of said second annular member, said second annular member having a plurality of transverse channels each of a selected width and depth formed in a peripheraledge thereof at selected angular positions and each such channelextending axially along such peripheral edge, rotatable means positioned under said annular members for supporting said annular members in mutually fixed nested concentric relation to define an annular air gap therebetween, a plurality of U-shaped permanent magnets mountedo'n said rotatable means at said selected angular positions of said transverse channels, each of said magnets having a pairVofs-paced poles extending upwardly from said rotatable means into respective engagement with said first andisecond annular members, and said permanent magnets being offset radially with respect to said annular membersso that one of said poles is displaced radially away from said rst annular member into said annular air gap and the. other of said poles is displaced radially toward said second annular member away from the corresponding one of said` channels therein, said permanent magnets producing a magneticux in said annular air gap which exhibits radial variations at positions corresponding to the angular positions of said channels, at least one stationary switching unit disposed in said annular air gap and including an armature constructed at least in part of magnetic material and responsive to such variatio'ns in the magnetic liux to control the operating condition of said switching unit, and means for rotating said rotatable means to produce relative motion between said switching unit and said pair of annular members so' as to bring said armature periodically under the iniiuence of said variations in said magnetic flux.

13. A switching assembly for controlling at least one stationary switching unit, said assembly including: a pair of annular members supported in concentric relation to define an annular air gap therebetween for receiving the switching unit and provided with relative co'ntours to produce an axial displacement in the' air gap in at least one position along the air gap, permanent magnet means associated with said annular members Vfor producing in said annular air gap a magnetic flux extending in an axial direction at successive positions along the air gap and exhibiting axial variations in at least the position of axial displacement in said air gap, and means for rotating said annular members and said permanent magnet means to produce relative motion between the magnetic fiux in the air gap and the switching unit to bring the switching unit periodically under the influence of the variations in the magnetic ux in said air gap.

14. In a switching unit, a casing made from an electrically conductive material, a plug made from an electrically conductive material and disposedat one end of the casing, a wire dispo'sed in the casing and extending from the plug, an armature made from a soft magnetic material and coupled to the wire for a pivotal movement, a first electrical contact carried by the armature at the opposite end of the .armature for a lpivotal movement of the contact with the armature, and a seco'nd electrical l contact supported by the casing but insulated therefrom l5. Inra switching unit, a casing having a first portion made-from an electrically conductive material and having a second portion also made from an electrically conductive material, a plug made from electrically conductive material disposed in the casing at one end of the iirst electrically conductive portion, a wire extending fro'm the plug, an armature coupled to the wire at one end for pivotal movement at the other end and made from a material having magnetizable properties, a first electrical contact carried by the armature at the free end of the armature, an insulating plug disposed in the casing at one end o'f the second portion of the casing, a second electrical contact extending through the insulating plug and disposed in the casing relative to the first electrical contact to engage the first contact upon a pivotal movement lof -the armature, the end of said second electrical contact extending through the insulating plug fo'rming a first terminal of theswitching unit mounted in electrically conductive contact with the second electrically conductive portion of said casing to form a conductive path through the switching unit when the second co'ntact engages the first contact, the conductive path being from the second terminal through the second portion of the casing, the first portion of the casing, the electrically conductive plug, the wire, the armature, and the engaged contacts to' the first terminal.

16.- The assembly set forth in claim 3 in which a plurality of additional switching units corresponding to the first switching unit are disposed in the annular air gap lfor response to the variations in the magnetic flux.

17. 'Ihe assembly set forth in claim 4 in which the first and second walls are provided with contours to define a plurality of displacements in the air gap and in which a plurality of switching units corresponding to the first switching unit are disposed in the air gap and are provided with resiliently mounted armatures to bring the armatures periodically under the inuence of the variations in the magnetic flux resulting from the displacements in the air gap.

18. The assembly set fo'rth in claim 9 in which one of the annular members is provided with a plurality of transverse channels and in which a plurality of stationary swltching units are disposed in the air gap and are provided with armatures responsive to the variations in the magnetic flux at the transverse channels.

19. In a switching unit, a casing being made at least 1n part from an electrically conductive material and forming an envelope for the switching unit, a first output terminal connected to the conductive material of the casing, a movable armature made from a magnetic and conductive material and electrically coupled at one end to the electrically conductive material of said casing, a first electrical contact carried by the armature at the other end of the armature, a stationary second electrical contact supported by said casing but insulated from the co'nductive material of said casing so as to be engaged by said first electrical contact upon a movement of said armature whereby a conductive path is established through the conductive material of the casing and through said first and said second contacts, and a second puttput terminal electrically connected to said second co'n- 20. In a switching unit, a casing being made at least rn part from an electrically conductive material and formlng an envelope for the switching unit, a rst output terminal connected to the conductive material of the casing, a plug made from an electrically conductive material and disposed in one end of the casing in electrical contact with the conductive material of the casing, a flexible and conductive wire disposed in the casing and extending from the plug, an armature made from a magnetic and conductive material and coupled at one end to the wire for a pivotal movement, a first electrical contact carried by the armature at the other end of the armature, a stationary second electrical contact supported by said casing but insulated from the conductive material of said casing and positioned in said casing so as to be engaged by said rst electrical contact upon a movement of said armature whereby a conductive path is established through the conductive material of the casing and through said first and said second contacts, a plug made from an insulating material at the other end of the casing for supporting said second contact, and a second output terminal supported Vby said insulating material plug and electrically connected to said second contact.

21. A switching assembly, including, a plurality of switches arranged in a circle, each of said switches having a movable armature, a circular rotor concentrically positioned in the circle of said plurality of switches and having a peripheral surface spaced from said plurality of switches to form an annular space between said rotor and said plurality of switches, means coupled to said rotor for rotating said rotor, and actuating means supported on said rotor in the annular space formed between the peripheral surface of said rotor and said plu? rality of switches and spaced from said plurality of switches for successively moving the armatures of said switches one after another without touching them as said rotor rotates said actuating means adjacent thereto.

22. A high speed cyclically operated switching assembly, including, a plurality of switches each including a movable armature having a normal and an operated position, means for supporting said plurality of switches in a circle of predetermined radius, a circular member positioncd concentrically in the circle ofsaid plurality of switches having a peripheral surface spaced at a predetermined distance from said plurality of switches to form an annular space between the peripheral surface of said member and said plurality of switches, actuating means supported on said circular member in the `annular space-between the peripheral surface of said member and said plurality of switches for actuating any one of said switches adjacent which it is positioned to move the armature of said actuated switch from its normal to its operated positions, said actuating means being spaced from any one of said plurality of switches adjacent which it is positioned so as not to touch any one of said switches at any relative position between said circular member and said switches, and means for establishing relative motion between said switches and said member to cause said actuating means to cyclically operate said switches.

References Cited in the file of this patent UNITED STATES PATENTS 2,112,214 Tognola Mar. 22, 1938 2,310,138 Whittaker Feb. 2, 1943 2,310,357 Edelman Feb. 9, 1943 2,488,373 Burton Nov. 15, 1949 2,508,508 Garvin May 23, 1950 2,547,003 Hastings Apr. 3, 1951 2,550,605 Schenck Apr. 24, 1951 2,609,464 Brown et al. Sept. 2, 1952 2,803,720 Mason Aug. 20, 1957 2,845,506 De Lucia Iuly 29, 1958 FOREIGN PATENTS 520,540 Germany Mar. l2, 1931 720,957 France Dec. 12, 1931