US2660639A - Electrical vibrator - Google Patents

Description

Nov. 24, 1953 H. J. BROWN 2,660,639

ELECTRICAL VIBRATOR Filed Feb. 19, 1948 3 Sheets-Sheet l Nov. ;24, 1953 H. J. BROWN 2,660,639

ELECTRICAL VIBRATOR Filed Feb. 19, 1948 s Sheets-Sheet 2 17: 9 6 INVENTOR.

A RNEIB Nov. 24, 1953 J, BROWN 2,660,639

ELECTRICAL v VIBRATOR Filed Feb. 19, 1948 I s Sheets-Sheet 5 INVENTOR. Harold Jflrown ATTORNEY! Patented Nov. 24, 1953 UNITED STATES ATENT OFFICE ELECTRICAL VIBRA'I'OR Application February 19, 1948, Serial No. 9,501

4 Claims.

My present invention relates to electric vibrators of the type useful for converting low to high voltage for automobile radio receiver and cognate applications.

It is among the objects of the invention to provide a vibrator of the above type of rugged construction, of relatively few parts and of small bulk for a given output, which shall be easy to assemble and all adjustments of which, including the longitudinal and lateral spacing of the armature relative to the pole of the coil and the relative position of each pair of electrical contacts thereof are easy to adjust without the danger of upsetting static or dynamic balance of the unit and Without the need for a running-in operation; the performance of which vibrator shall not be subject to derangement in the course of use or to fortuitous variation or deterioration even under severe service, which vibrator has a minimum of power loss and maximum efficiency of conversion, operates with a minimum of impact, a minimum of noise and a minimum of wear of its electrical contacts, transmits a minimum of mechanical vibration to the supporting frame or casing, does not become heated unduly in operation, is not subject to undesired variation with changes in ambient temperature nor to injury on reasonable overload; the efficiency of which is nearly uniform over a relatively wide range of input voltage and is maintained even after prolonged used and without damage to or from the associated apparatus, such as transformers or buffer capacitors, even though these associated parts are not held to close tolerances in their electrical constants.

According to one feature of the invention, a vibratory sub-assembly, which includes all of the vibrating elements has one or more contact carrying arms with each contact face thereof substantially at right angles to the plane of the length and width of the armature reed and is mounted for the free end or head of said reed to pass across the pole face of the vibrator coil, the stationary contacts associated with those on the vibratory assembly being afiixed with respect to the frame of the vibrator and in insulating relation therewith.

Another feature is to carry the vibratory electrical contacts upon spring arms affixed to the armature reed and exending laterally therefrom and to correlate the frequencies of vibration of the armature reed and contact carrying arms in such manner that each vibratory contact as it is about to close, moves in direction opposed to that imposed thereon by the armature reed, for a min- 2 imum of impact, a minimum of noise and a minimum of contact wear.

Another feature is to mount the vibratory assembly to the frame in such manner that in installing said assembly, the desired spacing of the reed armature end from the pole face of the coil may be set without strain upon the vibratory system and thereupon permanently affixed in place, the position of the reed armature end laterally of the said pole being thereupon set by manipulation of the vibratory assembly mount without strain upon any other moving or fixed parts of said assembly.

Another feature is to dispose the stationary contacts in guided relation on an insulating block afiixed upon the frame and thus to effect the required adjustment of spacing thereof with respect to the corresponding vibratory contacts without straining, displacing or even touching the I vibratory assembly.

In the accompanying drawings in which are shown one or more of various possible embodiments of the several features of the invention,

Fig. 1 is a side elevational view of the vibrator,

Fig. 2 is a, front elevational view thereof,

Fig. 3 is a top or plan view thereof,

Fig. 4 is a cut-away view of the completed vibrator assembly inside the shielding can,

Fig. 5 is a perspective view of the vibrating assembly of the vibrator,

Fig. 6 is a perspective view of the insulator base of the vibrator,

Fig. '7 is a side elevational view of a modification of the vibrator,

Fig. 8 is a front elevational view of the modification,

Fig. 9 is a top view of the modification, and

Fig. 10 is a perspective view of the vibratory assembly of the modification.

Referring now to the drawings, the frame It is desirably made of a strip of suitable ferrous alloy bent into U-shape with a cross bar it shown at the bottom and upstanding egs E2. The operating coil it rests at 23 against and is desirably affixed off center, as shown, to cross-bar iii between legs [2 by heading over at t! the reduced rivet end is of its core it against the outer face of said frame, said core having a widened pole 45 for coaction with the armature head 32.

All of the moving and vibratory parts of the unit are incorporated in a sub-assembly shown in Fig. 5. Preferably, the mount it of said subassembly comprises a pair of metal cross-plates l6 and I? pressed together by rivets 33 therethrough clamping in place the root 2B of the reed 55 21 sandwiched tl'ierecetween. Ihe relatively wide reed of spring metal is preferably cut away at 36 near its root or mount to afford a hinge of suitable flexibility and is furthermore cut away near its free end as at 3i for effective springiness and lightness. The widened free end or foot 2'! of the reed has the armature head 22 ail'ixed there to, which may be of any suitable construction. In a preferred embodiment, this head constitutes a rectangular plate of magnetic material having an j elongated central slot along which the plate is bent into a pair of identical leaves, the end bridges 32 left at the extremities of the slot 32' resting upon foot El, the head desirably welded in place as at The vibratory assembly carries desirably two vibratory contacts St, the contacting faces of which, as shown, extend laterally at right angles to the length and width of the armature reed at opposite faces thereof, and are set into vibration with and relative to the armature. To this end, the contacts 39 are desirably mounted upon con-- tact carrying arms each having a widened root web 38 riveted at 452, transversely across the wide reed ill at the mid portion t-ii thereof, between the hinging opening and the opening 3|, and each extending a cantilever outward at substantially right angles to said armature reed,

In the embodiment shown, the fixed contacts 36 which coact with the respective vibratory con-- tacts 39, are mounted each metal carrying bar 22, which in turn is appropriately affixed to the exterior of an insulating block. (3, which ole-- sirably has lateral grooves across the thicls ness thereof, accommodating the respective legs of the supporting frame ii between which the block 13 is mounted. The legs of the sheet metal frame are desirably bent outwardly and thence upwardly to afford shoulders 19 upon which the block it! rests, tabs to from the edges of the frame legs being turned inward over the insulating block it to lock it in The 22, each of which carries its stationary contact 36 on the overhanging ledge litthereof are desirably lodged in grooves 2% along the sides of the block and across the thickness thereof, in which they are clamped in place by appropriate screws 25, desirably self tapping screws threaded into apertures 68 in the block. Uesirably each bar 22 has an elongated slot 58 for the screw to permit of adjustment in the distance of the stationary from the corresponding vibratory contact in initially setting up the assembly for use.

The mount id for the vibratory assembly is assembled to the by lodging its extremities in corresponding slots 53 at the free extremity of the legs or the frame, the block it having an elongated slot 2i therethrough in which the armature reed is accommodated At least one of the mounting cross-bars ii is provided with extension tongues is bent over at right angles to engage the face of the frame legs it, to which it is soldered at it with desired spacing of the armature head 32 from the pole of the coil.

The cross bar mount M of the vibrator assem bly is desirably transvers ly slotted as at El? adjacent the ends oi the bridging length thereof be" tween the frame legs to permit a slight hinging displacement of such bridging member by resort to appropriate pliers for initially positioning the armature head as desired, laterally of the width of the pole this adjustment, the entire vibratory assembly is propedy positioned laterally with respect to the pole face this without strain upon any part other than the clamp mount l4. There being no sustained stress in operation upon said clamp mount, there is but slight tendency for shift in the adjustment of said clamp mount, and any such slight change would not be translated in strain upon any other part whether of the frame or of the vibratory assembly and accordingly progressive unbalance will not and cannot occur.

As illustratively shown in the embodiment of Figs. 1 to 6, the vibratory assembly may in addition to the two vibratory contacts 3E, be equipped with one or more additional vibratory contacts, such as driver contact H. To this end there is illustratively shown an additional contact carrying arm 35, preferably substantially identical with arms 34 and affixed to the vibratory reer by the same rivets 42 as afixed arms 35. Arm carries contact 4! to extend laterally of one of the corn tacts 3?}. The enacting fixed contact 3! is mount ed on a metal bar (iii similar to bars 22 and aflixed by a screw 25 to the insulating block !3 in corresponding groove 23 across the thickness thereof in the same manner and with facility for the same adjustment of its position as in the case of the vibratory contacts 3%.

The unit as thus far described with or with out the driver contacts 35, 4| is equipped with terminals and installed in more or less conventional manner, as shown in Fig. 4. Desirably the three terminal leads 51 afhxed to the root ends of the three bars 22, 22 and to carrying the respective stationary contacts 36, 36 and 4!, are affixed to appropriate terminal prongs E3 installed in a fiber plate 64 covered with a cor racing a resistor 82 being connected between bar 6%? and the frame 12, the entire unit being enclosed in a sponge rubber liner housing 86 and introduced into a metal can 6! spun over the fiber disc 6 to complete the assembly. The fourth prong 63 is the usual dummy that serves for keying the unit to its socket.

A preferred structure of vibrator has been above described but without reference to certain important features now to be set forth which, while preferably incorporated in the structure set forth, may find utility in other structures as well.

The contact carrying arms 34 and the contact carrying arm 35, if used, are according to the present invention made of spring metal, so that they, like the armature reed 321 will have a natural frequency of vibration. Desirably the natural frequency constants, namely, the length, the elastic modulus and the masses of the moving arms, that is of the armature reed 21 and of the contact carrying arms 34, are so selected that the vibratory contact will, as it is about to close, move in direction opposed to that imposed by the armature reed. In other words, while the armature reed moves, say toward the left in Fig. l, tending to shift contact 39 upwardly toward contact closure, the arm 34 carrying said contact is at that time moving downward away from contact closure, so that the speed of approach of moving contact 39 to the fixed contact 36 imposed by the armature reed 21 is offset in large part by the opposing movement of the contact carrying arm 3 Thus the contact closure will be with less impact, less noise and less wear than if the contact 39 were inimovably affixed with respect to the moving armature reed 2?, and much less than would be the case if the speed of movement of the contact 39 imposed by the independent vibration of its carrying arm 34 were added to rather than subtracted from that imposed by the vibratory armature reed 21.

To this end, especially for vibrators in the lower ranges of frequency (i. e. in the range be low 150 vibrations per second), the ratio of the compliance (i. e. the deflection within the elas tic limit per unit of deflecting force) of the armature reed to that of the contact carrying arm approximates but is not less than eight times the square of the ratio of the effective lengths of said arms. When this relation obtains a minimum of adjustment is required, correctly to time the vibrator.

For best operation, the time constant, that is the ratio of the period that any of the vibratory contacts as is closed to that of a complete cycle of the vibrator should be not less than 80 per cent and not more than 93 per cent.

The vibratory unit, as shown in Fig. 5, with armature reed and contact carrying arms of known compliance, is assembled with due regard to proper selection of three variables that determine its performance. These variables are the effective weight of the armature, the thickness of the armature reed 21 and the thickness of the contact carrying spring arms 34. The thickness of the armature reed and of the contact carrying spring arms may be readily selected as may be the armature head 32 whose weight may be readily adjusted by suitable grinding.

The vibratory assembly is easily and correctly installed in the carrying frame therefor with but three separate adjustments, each of which is made independently of the other two and without disturbance of the other two. The three adjustments in question are the setting of the vibratory assembly in correct position longitudin aliy for desired spacing of the armature head 32 from the pole face 45, the setting of the armature head for proper spacing thereof laterally of the width of pole 45 and the setting of the distance between each vibratory contact and its associated stationary contact.

To set the armaturereed longitudinally and the gap between armature head 32 and pole a suitable gauge blade is interposed between the said head and said pole. In position thus determined by the gauge, the mounting cross bar M of the vibratory assembly is soldered to the frame iii in manner previously described. Thereupon the bridging portion of the mounting cross bar 54- between the legs of the frame is 1011.- gitudinally deflected as permitted by cross slots 5a to set the position of the armature head 32 in desired position laterally of the pole width 45.

To permit check of the critical rest position of the armature head 2 relative to the pole 45, at least one leg !2 of the frame is provided with a circular window aperture 44 exposing to inspection the armature head 32 and the associated part of the pole 45.

Independently of the above adjustments, the correct spacing between electrical contacts is established by slight sliding adjustment of the stationary contact carrying bars 22 in their grooves 24 and then tightening screw 25, a suitable gauge being interposed between the contact pairs for correct spacing in full open position thereof.

Thus in completing each setting, there is no disturbance of the accuracy of the settings previously made and there is no strain upon the metal parts in making any such setting and,

6 therefore, no progressive deterioration in operation during use by objectionable disturbance in the static or dynamic balance as might ensue by plastic flow of metal were the vibratory parts subjected to mechanical strain or d formation for the purpose of forcefully effecting such adjust mcnt. Accordingly, with the parts properly selected and installed in the manner above described, the operation will be reliable and its reliability will be maintained without disturbance for long periods of time.

Of course, by suitable choice of parts and appropriate positioning thereof, the device could be made to function at any frequency within practical limits, bearing in mind that frequency varie inversely the square root of the prod not of the equivalent mass and the equivalent compliance of the vibratory system.

By reason of the accuracy of adjustment of which the vibrator admits, no running-in operation is required, and the correct setting is maintained throughout.

By reason of the low losses due to the elimination of excessive impart in contact clothere is a minimum or wear and a maximum utilization of the input energy. The unit within its sound insulating housing, as shown in 4i, transmits a minimum of vibration and a minimum of noise. The unit will perform without much loss in efficiency over relatively wide range of For instance, a vibrator according to the present invention, designed to operate from a o-voit battery will operate efl'ectively between the ranges or 2 volts and 19 volts and will withstand substantial overload through out its voltage range and without serious injury thereto.

Moreover, the unit by reason of all of the characteristics set forth, does not require associated electrical equipment such as transformers and buffer capacitors of or: icai specifications, and yet there no danger of injury to or from the latter under various conditions of opera n.

Accordingly a unit for a given rrnance may be more compact than units that lack the characteristics set In the embodiment of i 7 to the vibratory contacts be are four in number, each mounted on its spring arm the two ing arms on each side being shown formed integrally. construction serves for heavier duty or sel'- rectifying operation in manner clear to those skilled in the art.

The reed and contact carrying spring arms are riveted at 83 to a separate and distinct hinge spring piece so preferably of greater flexibility than the reed and riveted at 33* to the cross arm mount it and affording a principal region of fiexure at spring hinge portion at. Except as above stated, and that a specifically difierent arrangement of driver contact is here shown, the present embodiment is similar to that heretofore described, and corresponding parts bear the same reference numerals with ex= ponent a. In this embodiment the insulating block it is provided with a unitary extension "to at the lower end thereof and desirably has molded thereinto at aperture it a metal bushing 73 grooved at so and which may be tapped at if: to accommodate a screw to mounting a terminal tab as, said screw being adjustable at a fillister head 3! and carrying a contact s2 at its inner end for coaction with a contact spring "it which has a loop 35 for enhanced flexibility, is desirably '7 integral with hinge spring piece and is exposed for engagement with said contact 82 through the opening ill in the armature reed 21'.

A many changes could be made in the above construction and many apparently Widely dif ferent embodiments of this invention could be made Without departing from the scope of the claims, is intended all matter contained in the above description or shown in the acccm panying drawings shall be interpreted as illustrative and not in a limiting Having thus iescribecl my invention, what I c t. new and desire to secure by Letters Patent or. the United States 1, An electric vibrator comprising a substantially U cha ned name of magnetic material havin clids spaced from each other, the legs d frame having projecting shoulders across 1 a Wl ith thereof, coil mounted on the cross bar of the frame between. the legs thereof, said coil having a pole, a vibratory assembly having a mount g between and al'lixed to the free ends of said legs, vibratory assembly including arniatwre reel longitudinally of the i1 no and hav d spaced longitudinally and c acting with sw. pole, vibratory assembly including one or more is or ally extending; vibratory arms, an electric contact carried near the end oi each of said arms, an insula block carried on the shoulders of said legs, c.rtending thcrebctvveen and disposed between coil and the vibratory assembly mount, sai legs inturned tabs extending over sa "lock to retain the latter on said shoulders, said block having a passageway therethrough for reed, and stationary electrical contacts mounted on said insulating block and coacting with the spective contacts of the vibratory assembly.

2. An electric vibrator comprising a substantially U-shaped frame of magnetic material having its free ends spaced from each other, a coil mounted on cross bar oi the frame between the legs th reoi', said coil having a pole, a vibratory assembly having a mount extending between and affixed to the free ends of said legs, said vibratory assembly including an armature reed longitudinally of the frame and having a head spaced longitudinally of and coacting with said pole, vibratory assembly including one or more laterally extending vibratory arms, an electric contact carried near the free end of each of said arms, an insulating block carried by frame extending between. the legs thereof and disposed between the coil and the vibratory assembly mount, said block. having a passageway therethrough for said reed and having grooves on the exterior across the thickness thereof, stationary electrical contacts coasting with the respective contacts of the vibratory assembly, upstanding bars mounting said stationary contacts respectively and adjustable lengthwise of an associated groove for adjustment of the spacing of each stationary contact with respect to the corresponding vibrating contact.

3. An electric vibrator comprising a substantially U-shaped frame of magnetic material having its free ends spaced from each other, said ends each having a longitudinal slot therein, a coil mounted on the cross bar of the frame be tween the legs thereof, said coil having a pole, a vibratory assembly having a cross bar extencling between the free ends of the frame and lodged in said longitudinal slots, said vibratory assembly including an armature reed longitudinally of the frame having its base affixed to said cross bar and having a spaced longitudinally of and coacting with pole, said vibratory assembly including one or more laterally extending vibratory arnis, an electric contact carried near the free end or each of said arms, an insulating block carried by said frame extending between the legs thereof and disposed between the coil and the cross bar, said block having a passag ay therethrough for reed, and stationary electrical contacts mounted on insulating block and coacting a the respective contacts of the vibratory assembly.

l. The combination recited in claim in which sail cross-bar is transversely slotted near its opposite ends to permit slight twisting thereof or lateral adjustment oi the armature head With aspect to the pole.

HARQLD .3. BROWN 'iteierences Cited in. the file of this patent UNITED STATE PATENTS

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