US2120273A - Vibratory motor device - Google Patents

Description

June 14, 1938. E. 1 BARRETT VIBRATORY MOTOR DEVICE Filed Oct. l2, 1936 lio Patented June 14, 1938 UNITED STATES *PirrlsN'r oFFlcE I K amsn "y Application october 12.1936, serial No. 105,2:97

10mm. I'he invention relates generally to vibratory motor devices and more particularly to devices of this character which are especially vwell adapted for use as a circuit interruption means in electrivcal systems for transforming direct currentinto alternating current, and thencev into direct cur-4 rent, such systems'for example being largely employed'at present in providing electrical energy of proper potential forthe operation of a motor vehicle installation of a radio receiving set.

Such devices ordinarily include a vibratory reed driven by periodically energized electromagnet, the reed serving to open and close two or more main circuit controlling contacts. It has tion of the electromagnet by a separate set of driving contacts also operated by the vibratory reed. vArcing at the driving contacts has, however, been a serious problem in such devices, and although various expedients have beenproposed to eliminate such arcing, none of them, so far as is known, have proved to be completely effective in actual operation.

One object of the present invention is to provide a device of the type indicated having an electromagnet periodically energized through a circuit controlled by a pair of make and break driving contacts, the energizing winding of the electromagnet being of a novel form and of such character as to minimize arcing atvthe driving contacts..

y A more specinc object of the invention is to provide ina vibratory motor of the type set forth a novel form of actuating electromagnet coil adapted to minimize arcing at the driving contacts and embodying a conductive sheath surrounding substantially throughout its length the wire'making up the coil or winding of the electromagnet but insulated therefrom. 40

y Further objects Vand advantages of the invention will become apparent as the following description proceeds and the features of novelty whichcharacterize 'the invention are pointed out with particularity in the claims annexed to and 45 forminga part of this specification.

' Fora. better understanding of the invention, reference may be had to the accompanying drawing, in which:

Figure l i's a perspective view' on a reduced 50 scale oi" a vibratory motor device embodying the features of the invention, the enclosing case therefor being shown in broken outline.

Fig. 2 is an enlarged longitudinal sectional view of the vibratory motor assembly shown in 55 Fig. l.

heretofore been proposed to control the eniergiza-` (Cl. 20C-00) l of the vibratory motor electromagnet.

For purposes of illustration, the invention has been shown as embodied in a vibratory motor particularly adapted to meet the exigencies of use in an automobile radio receiving set, although it is susceptible of a variety of other uses. In general, the vibratory motor includes two pairs of main circuit controlling make and break contacts Il-Il andYI2-i3, and a pairof driving contacts Il-i, all operated by a vibratory reed I6 which is driven by an actuating electromagnet I1.

In the preferred construction illustrated, the various parts of the vibratory motor are assembled on a rigid frame designated generally by the numeral Il. 'Ihis frame is preferably of one-v piece construction which includes a part for supporting the reed and contacts and another part constituting the core of the winding, these parts all being located substantially on the same plane. Such a frame may be readily stamped or otherwise formed from a flat sheet of metal stock such as cold rolled steel. 'Ihe latter material is' suggested as it is desirable that the frame have a high magnetic permeability. Referring particularly to Fig. 3, it will be seen that the frame il is of generally rectangular shape and includes end members I! and 2l joined by side members 2| and 22. A projection 23 on the end member I9 forms a core for the electromagnet I1. 'Ihe side mem- -bers 2| and 22 are oil'set somewhat from the plane of the end members in order to facilitate inspection and adjustment of the contacts after the device is assembled.

The reed I6 is of the cantilever type4 and is adapted to flex substantially throughout its length, being preferably made of spring steel or bronze. An elongated opening 24 is formed in the center of the reed in order to give it certain preferred flexing characteristics and also to insure unimpeded flexure of the reed despite the multiplicity of associated contacts as is hereinafter described in great detail. Upon reference to Fig. 3, it will be seen that the opening 24 increases in cross section adjacent the outer end of the reed, thereby providing a greater i'lexui'e in that portion. A rectangular armature 25 made of steel or other material having a high magnetic permeability is spot welded or otherwise rigidly secured to the free end of the reed. 'I'his armature is disposed in driven relation with respect to the pole piece 23 of the electromagnet I1.

The movable contact points II and i3 of the respective pairs of main driving contacts are carried by the reed I6 intermediate its ends and are preferably positioned substantially in the plane of the reed in order to interfere as little as possible with its normal vibratory characteristics. These contact points II and I3 are secured to ' contact supports 26 and 21 respectively, made of current conducting metal stock, these supports being in turn carried by the reed I6 to which they are securely fastened by rivets passing through holes 28. It will be noted that the supports 26 and 21 span the`opening 24 so that the contact points II and I3 are disposed in alinement with the opening.

Relatively fixed contact points I0 and I2 are disposed on opposite sides of the reed I6 and cooperate with the movable contact points Il and I3 to periodically open and close the associated electrical circuits upon vibration of the reed. A pair of sheet metal ngers 29 and 30 support the contact points I0 and I2 in spaced relation with respect to their associated movable contacts when the reed I6 is in its idle position. It will be noted that the fingers 29 and 30 are provided with enlarged base portions 3| and 32 respectively, having terminal lugs 33 and 34 thereon. These bases also include integral laterally extending assembly lugs 35 and 36 projecting from the lower edges thereof. In the assembly of the device, these lugs cooperate with a suitable abutment to position the contact supports with respect to the reed and frame in order to bring the contact points into proper alinement and I also to space the edges of holes 31 and'38 in the contact support bases from the securing screws 39 which pass therethrough. The general vibratory motor structure described above forms no part of the present invention but is described and claimed in prior Patent No. 2,072,578, issued March 2, 1937 on a copending application filed by Edward L. Barrett and Max J. Manahan.

An improved and simplified supporting structure has been provided for the driving contacts I4 and I5 which may be incorporated with the remainder of the vibrator structure without materially aiecting the arrangement of the parts or method of assembly. In general, this supporting arrangement preferably includes a sheet metal supporting finger which is disposed in superposed relation with respect to the supporting ngers for the main circuit controlling contacts, whereby a compact, readily assembled stack of laminations or parts is had. Thus, in the preferred construction illustrated one of the driving contacts I4 is carried by sheet metal supporting finger 40, being secured thereto by a thin, light, metal spring 4I which is riveted adjacent its lower end to the supporting nger. This supporting nger 40 is provided with a base portion 42 having a terminal lug 43 thereon, as well as assembly lugs 44. These assembly lugs are disposed in alinement with the assembly lugs 35 and 36 on the supporting lingers 29 and 3D so as to facilitate accurate alinementof the parts during assembly. Enlarged holes 45 are also provided on the base portion 42 of the supporting iinger 40. A cooperating driving contact I5 is carried by the reed I6 and may be mounted on the supporting member 21 which carries the main circuit controlling contact I3. A pin 46 made of aluminum, brass or other light weight material which will nt interfere with the vibratory movement of the reed I6 projects laterally from the upper end of the supporting member 21 and the contact point I5 is secured to this pin. The inner end of the pin 46 is of a reduced diameter and projects through a registering hole in the support 21. The driving contacts I4 and I5 il-l lustrated are preferably made of palladiumsilver alloy and the contact I5 is welded to the pin 46.

In assembling the parts of the vibratory motor device described above, insulating lspacers 41 to 52 inclusive, made of sheet mica or the like are interposed between the various adjacent elements in the relation shown in Fig. 3, in order to electrically insulate the same. The reed I6 and contact supporting fingers 29, 30 and 40, together with their associated insulating spacers, are secured in position on the lower end member 20 of the frame I8 by the screws 39 which pass through alined holes therein. A metal spacer 53 is provided at one end of the stack to prevent scoring of adjacent insulating spacer by the heads of the screws, and a similar member 54 is provided at the other end of the stack, having tapped holes 55 therein in which the ends of the screws 39 are threaded. Metal spacers 56 are provided between the various elements of the stack in order to space the contact points the ldesired distance apart.

In accordance with one aspect of the present invention, an improved form of actuating winding is preferably provided for the electromagnet I1 which is particularly adapted to minimize arcing between the associated driving contacts III-I5. In general, this improved actuating winding includes a wire disposed in a coil in the usual manner, the Wire being provided with an electrical conductive sheath surrounding the same and insulated therefrom substantially throughout its length.- There are probably several factors which theoretically contribute to the improved result attained when such an arrangement is utilized. Thus, capacitance between the core of the wire and its insulated conductive sheath aids in suppressing the arcing at the driving 4contacts and in addition the eddy currents and other losses due to the sheath aid in attaining the desired result. By the use of such an arrangement, a comparatively heavy current ow through the electromagnet winding may be had for starting the reed in its vibratory movement, but after this operation has been initiated the sheath apparently acts toI reduce the flow of current at the instants at which the driving contacts open and close so as to minimize the arcing therebetween.

It has been found that an effective electrical conductive sheath for the wire of the electromagnet Winding may be had by treating the insulating covering of a'standard form of insulated wire in the manner hereinafter set forth.. One standard commercial form of ne copper wire suitable for use in such a device has a coating of insulating enamel thereon, which is in turn surrounded by a serving or covering of textile material such as cotton or silk. Thus, in the conductor shown in Fig. 5, a fine copper wire 51 has a coating of insulating enamel 58 and a serving of cotton strands 59 thereon. The conductive sheath may be readily formed by lling the interstices of the textile covering with electrical conductive material. It has been found that a good sheath is formed by impregnating a cotton length by a conductive sheath formed from a cotton serving impregnated with colloidal graphite as described above. 'lhe wire is wound on a spool 8i of insulating material which may be slipped over the pole piece 28. Although such a sheath formed from textile material impregnated with graphite has a resistance which is comparatively high with respect to the resistance of the associated copper wire, Athis effect is not detrimental in that the adjacent turns of the winding are disposed in close contact so that the f resistance across the surface of the coil is low nected to the sheath so that a denite potential relation thereto will be had.

'I'he vibratory motor device described above is preferably assembled with a supporting means which includes an enclosing casing Il in the form oi an elongated cup-shaped container having an open end.A This open end'of the container is closed by a disk of insulating material M carrylng suitable contact prongs 85 connected to the various elements of the vibratory motor. A resilient support for the motor within the casing is formed by sponge rubber blocks B6 and B1.

'I'he block 66 is generally disk-shaped and receives the lower end of the motor. The upper end of the motor is surrounded by cup-shaped block 61.

'I'he wiring diagram Fig. 4 illustrates one application of the vibratory motor device in which the main circuit controlling contacts l-Ii and I2- i3 serve to periodically connect the storageY battery 68 to the respective sections 69 and 10 of the primary winding of the transformer 1I. 'I'he operation of this circuit is initiated by the closuretof a starting switch 12 which connects one terminal oi' the electromagnet actuating winding 60 to one terminal of the battery 68 through conductors 'I3 and 14, switch 12 and conductors 15. The other terminal of the actuating winding 60 is connected to the other terminal oi the storage battery through conductor 18, the normally closed driving contacts M-ll. reed i6 and conductor 11. Upon the completion of this circuit, current ows from the battery Il through the actuating winding 60 of the electromagnet so that the armature is attracted from its idle position in kwhich it is eccentrically disposed with respect to the pole piece 28, thus swinging the reed i6 to the left (as viewed in Pig. 2) and closing the contacts l--IL This swinging movement of the reed also opens the driving contacts ll-li, thereby deenergiiiingl the electromagnet winding 60. The closure of the main circuit controlling contacts I il-II` completes a circuit for section 69 of the transformer winding. Thus, one

terminal of this transformer section is permanently connected to the battery il through conductor 13 while the other terminal thereof is connected to the opposite terminal of the battery through the conductor 1,8, contacts lil-II,

reed il and conductor 11. Since the electromagnet hasgbeen deenergized,the reed' II will swing back. Opening the contacts iO-II and again closing the driving contacts M-Il The return impulse of the reed is suiilcient, however, to close the second pair of main circuit controlling contacts l2-Il in its return movement so as to complete a circuit lfor a second section 'Il of the transformer primary winding. One terminal of this section is permanently connected to a terminal of the battery. through conductor '|8,v A

while the opposite terminal is connected to the second terminal of the battery through a conductor 1l, contacts if-II, reed I, and conductor 11. This cycle oi' movement of the reed It is repeated and continued with great rapidityl so that impulses of direct current flow through the transformer primary winding sections l and 10. These impulses of current induce an alternating current in the transformer secondary winding which may be rectified and utilized in a radio receiving set or the like. The preferred construction illustrated, in which all of the various contacts are disposed in alinement with the aperture 24 in the reed I8 permits the latter to swing with a wide amplitude of movement without impediment from the contacts disposed on its opposite sides. ,Also the time efllciency is high. that is the main circuit controlling contacts remain `closed during a comparatively large portion of each cycle of movement of the reed. It is particularly important that the reed have a large amplitude of free movement when an improved electromagnet actuating winding of the type described is utilized since a heavy initial impulse is given to the reed at starting.

Although a preferred embodiment of the invention has been illustrated and described in some detail, there is no intention to thereby limit the invention to such a preferred embodiment but, on the other hand, the appended claims are intended to cover all modifications within the spirit and scope of the invention.

I claim as my invention:

1. In a vibratory motor, an actuating electromagnet including an electrically conductive wire disposed in the` Iiorm of a coil, means including a pairof cooperating make and break contacts for periodically connecting said coil to a source of current, and means including a conductive sheath disposed about said wire and insulated therefrom substantially. throughout its length for minimizing arcing at said contacts.

2. In a vibratory motor, an actuating electromagnet including an electrically conductive wire disposed in the form of a coil, means including a pair of cooperating make and break contacts for periodically connecting said coil to a source of current, a coating of insulation on said wire. a covering of textile material on said insulation, both said coating and said covering extending substantially throughout the lengthof said wire in said coil, an electrically conductive material lling the interstices in said textile covering to form a conductive sheath for said wire, 'the ad-` jacent turns of said coil being disposed in` con-itacting relation. l

3. In a vibratory motor, an actuating electromagnet including an electrically conductive wire disposed in the form of a coil, means including a pair of cooperating make and break contacts substantially throughout the length of said wire in said coil, said covering being impregnated with colloidal graphite to form a conductive sheath for said wire, the adjacent turns of said coil being disposed in contacting relation.

4. In a vibratory motor, an actuating electromagnet including an electrically conductive wire disposed in the form of a coil, means including a pair of cooperating make and break contacts for periodically connecting said coil to a source of current, and means including a conductive sheath disposed about said wire and insulated therefrom substantially throughout its length for minimizing arcing at said contacts, the adjacent turns of said coil being disposed in contacting relation thereby forming a low resistance path through adjacent contacting portions of said sheath from end to end of the coil.

5. In a vibratory motor, an actuating electromagnet including an electrically conductive wire disposed in the form of a coil, a cantilever vibratory reed, an armature carried by the free end of said reed in operative relation with said electromagnet, means including a pair of cooperating make and break contacts actuated by said reed in the vibratory movement thereof for periodically connecting said coil to a source of current, and means including a conductive sheath disposed about said wire and insulated therefrom substantially throughout its length for minimizing arcing at said contacts.

6. In a vibratory motor, an artuatng electromagnet including an electrically conductive wire disposed in the form of a coil, a cantilever vibratory reed, an armature carried by the iree end of said reed in operative relation with said electromagnet, means including normally open contacts disposed on opposite sidesv oi said reed and actuated thereby for periodically opening and closing associated circuits, means including a pair of cooperating normally closed make and break contacts actuated by said reed. in the vibratory movement thereof for periodically connecting said coil to a source oi current, and means including a conductive sheath disposed about said wire and insulated therefrom substan` tially throughout its length for minimizing arcing at said normally closed contacts.

7. In a vibratory motor, an actuating electromagnet including an insulated electrically conductive wire disposed in the form of a coil, means including a pair of cooperating make and break contacts for periodically connecting said coil to a source of current, and means including a mass oi conductive material interposed in the interstices of said coil of insulated wire between individual turns thereof for minimizing arcing at said contacts.

EDWARD L. BARRETT.

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