US2259131A - Vibrator - Google Patents

Description

0d 14, 1941- F. H. FLElscHER ETAL 2,259,131

I VIBRATOR Filed May 5, 1959 2 Sheets-Sheet l `Figi lg Z6 Figa.

Invehtors: Fran k H.' Fleisch er,

Wagne J. Morrill, by We. MIM

Them Attorn eg.

OC- 14, 1941- F. H. FLElscHER l- TAL 2,259,131

VIBRATOR Filed May 5, 1939 2 Sheets-Sheet 2 Inventors.- Frank H.F`|eischer`, Wayne J. Morrill,

b5 .7E/M76.

Patented ct. 14, 1941 UNITED STATES;

PATENT .OFFICE vmnn'roa Frank H. Fleischer an d Wayne J. Morrill, Fort Wayne, Ind., assignors to General Electric Company, a corporation of New Yorkf Application Mays, 1939, serial No. 271,948

1 Claim.

The present invention relates to electromagnetic vibrators for producing an oscillating or. reciprocating movement such as may be used for operating electric shavers and the like.

'I'he object of our linvention is to provide an improved construction and arrangement in vibrators of this type, and for a consideration of what we believe to be novel and our invention,

attention is directed to the following description and the claim appended thereto. l

In the accompanying drawings-Fig. 1 1s a top plan view of a shaver equipped with a vibrator embodying our invention, the upper half of the .casing being removed; Fig. 2 is a sectional view taken on line 2-2 of Fig. 1; Fig. 3 is a sectional view taken on line 3 3 of Fig. 2; Fig. 4 is a per- I is a cutter 6 which is reciprocated by an operating lever 1 having a rounded end 8 fitting in a notch 9 in the cutter. It should be noted that the operating lever is connected to one end of the cutter. This reduces sliding of the rounded end 8 in the notch 9 as the operating lever is oscillated, thereby reducing wear and friction This is due to the fact that the motion losses. of the operating lever is almost wholly in the direction of movement of the cutter. The construction of the cutter and shearing head form no part' of th`e present invention. Current is supplied to the vibrator by a conductor cord I led in through an opening II in the opposite end of the casing.

The vibrator has a'U-shaped framev I2 having exposed longitudinally extending arms -I3' and I4 fixed together by cross braces I5 and, I6 having projections I1 and I8 which project through openings in the arms I3 and I4 and are ,riveted over the outer surfaces of the arms. This provides a rigid frame construction in which the arms are clamped against the ends ,I9 and 20 ,of the braces I and I6. Between the arms I3 and I4 and extending transversely or crosswise thereof is an electromagnet having*l a core 2| vprovided'with projections 22 and 23 at opposite ends which fit in openings 24 and 25 in the 30 between the frame arms.

a plurality of laminations which extend perpendicular to the, arms I3 and I4 of the frame. The laminations are in general H-shaped, the legs of the H projecting outward from opposite sides 5 of the core adjacent the inner side of the arms I3 and I4 to provide pairs of spaced pole pieces 26 and 26a and 2'I and-21a. The active faces of each pair of pole pieces are the inner or opposed faces which provide a recess for receiving an armature. The electromagnet is energized by a coil 28 on the core 2| and connected to the conductor cord I0 which is led along the under side of the frame arm I4 in a groove Illa in the casing. The conductor cord is held adjacent the. l5 frame arm I4 by a clip IIlb thereon. The pole pieces 2G and 21 have a polarity opposite that of the pole pieces 26a and 21a. When the coil is energized from a `source of alternating or pulsating current, the ux at the pole pieces uctuates in magnitude in accordance with the variations in current owing through the coil.

Fixed to the end of the frame I2 adjacent the shaving head is a U-shaped strip spring 29 having its central portion xed by screws 3|) to the end of the frame and having spring arms 3| and 32 extending along opposite sides of the frame.`

The arms 3| and 32 are perpendicular to the frame arms I 3 and I4 and extend along the edges thereof so as to substantially enclose the space Fixed to the spring arms 3| and 32 are armatures 33 and 34v arranged in the recesses between the inner or opposed faces of the pole pieces 26 and 26a and 21 faces of the pole pieces and are supported by the spring arms for movement parallel to the inner faces of the pole pieces. The spring arms bias the armatures to an outer position in which the edges of the armatures are slightly beyond the ends of the pole pieces. As the current in the coil increases, the armatures are drawn inward toward the coil to a position in which the edges of the armatures are beneath the inner faces of the pole pieces. As the current in the coil decreases, the armatures are moved outward by the spring arms. The recesses provided by the pole pieces provide ample space for the oscillation of the armature without striking the coil. 'I'he pieces. This eliminates the need for stops. The strength of the springs and the weight of the frame arms I3 and I4. 'I'he core 2| comprises 5s armatures are adjusted so that the natural frequency of` vibration of the armatures is tuned to a frequency slightly below twice the frequency of the current energizing the coil. If the natural frequency of vibration of the amature were exactly equal to twice the frequency of the energizing circuit, the amplitude of oscillation of the armaturewould be limited by the friction load on .the operating lever 1. Inthe particular application this would mean that as the cutter 8 encountered heavier or stiffer hair, the amplitude of movement of the cutter would decrease and mighteven decrease to suclan extent as to prevent satisfactory cutting. By having the natural frequency of the armature slightly below twice the frequency of the current supply the amplitude of oscillation actually increases as the loadon the cutter increases. This eliminates any possibility of unsatisfactory cutting due to a decrease of the cutter amplitude as the cutter load increases. The tuning or natural frequency of oscillation of the armatures is adjusted by weights 35 and 36 on the free ends of the armatures. The weights project beyond the, end of the frame and, during oscillation, move between the frame arms kI3 and i4. The armatures vibrate in synchronism with the pulsations of the current. Such armatures are known in the art y as the vibrating reed type. Since the armatures move in opposite directions, the reaction forces transmitted from the spring arms 3| and 32 to the frame are neutralized. The end of the armature 34 opposite the endunder the inuence of pole pieces 21 and 21a isfixed to the operating lever 1. Since the spring arm 32 in eect supports the armature 34 for pivotal movement about a point adjacent the portion of the spring 23 connecting the arms 3l and 32, the armature is supported intermediate its ends. This has the advantage of applying greater leverage to the operating lever 1. Y

In use, the vibrator is supplied from a source of alternating or pulsating current oi' the proper frequency. As' described above, this causes a synchronous vibration of the armatures 3,3 and 34. The vibration of the amature 34 is transmitted to the operating lever 1. The vibration of`the armature 33, being equal and-opposite to that of armature 3l, neutralizes the reaction forces'on the frame of amature 34 and accordingly prevents vibration. of the shaver casing.

What we claim as new and desire to secure by Letters Patent in the United States is:

In an electromagnetic vibrator, a frame having spaced longitudinally extending arms, an electromagnet having an H-shaped core extending crosswise of said arms and fixed at each end to the adjacent arm,` the armsv of said core providing pairs of spaced pole pieces on opposite sides of the electromagnet, a coil on the central` part of the core, longitudinally extending spring arms xed to one end of the frame and extending toward the electromagnet, armatures xed to the spring arms and supported `thereby'for pivotal movement about a point yadjacent the point of attachment of the spring arms toward and away from a position Vbridging said pole pieces, said armatures extending beyond the electromagnet and having balance weights on the free ends, and an operating lever xed to one of vsaid armaturesl and extending away vfrom the electromagnet and beyond -the pivot point of the armature.

f f FRANK H. FLEISCHER.

WAYNE J. MORRILL.

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