US1645139A

US1645139A - Mechanical vibratory system

Info

Publication number: US1645139A
Application number: US675089A
Authority: US
Inventors: Henry C Harrison
Original assignee: Western Electric Co Inc
Current assignee: AT&T Corp
Priority date: 1923-11-16
Filing date: 1923-11-16
Publication date: 1927-10-11
Anticipated expiration: 1944-10-11

Description

0 u Oct 7 H. c, HARRISON MECHANICAL VIBRATORY SYSTEM Filed NOV. 16. 1923 Patented Oct. 11, .1927.

UNITED s'rArEs ma 0. HARRISON, OF PORT WASHINGTON, NEW YORK, ASBIGNOR TO WESTERN ILEGI'BIO COMPANY, INCORPORATED, OF NEW NEW YORK.

MECHANICAL VIBRA'IOBY SYSTEM.

Application fled November 18, 1923.' Serial No. 675,089.

This invention relates to mechanical vibratory systems, and more particularly to those suitablefor the transmission of sound wave energy and has for its object improved joints between relatively movable members ot such system.

In accordance with one feature of the invention the vibratory member and its support are connected by means of a plurality of strips of thin material unrestrained at their edges and disposed in planes intersecting at the axis of oscillation.

Another feature provides a coupling between the driving and the driven members comprising a strip of thin material folded back and forth on itself so as to efficiently transmit vibrations in the desired direction and inefliciently vibrations in other directions.

Referring to the drawings;

Fig. 1 shows a magnetic system suitable for loud speaking receivers embodying invention;

Fig. 2 shows a recorder or reproducer embody'ing the invention;

Fig. 3 is a sectional view through 3-3 of Fig. 2;

Fig. 4 is an enlarged detailed view showin; the flexible coupling;

Fig. 5 is an enlarged detailed view showing the flexible mounting for the armature.

A magnet 5 is provided with bifurcated pole pieces 6 and 7, preferably of laminated soft iron, which may be secured thereto by means of clamping plates 8 and 9. Between the arms of the pole pieces 6 and 7, at right angles thereto and inwardly projecting therefrom, are auxiliary poles 10 and 11 each of which is provided with a short circuited winding 12 consisting of one or more turns of non-magnetic material such as copper, or nickel-silver. Across the gap between each pair of the auxiliary poles 10 and 11. is

a thin piece of high hysteresis steel 26 which may be held in place by the short circuited windings 12. Between the

arms

27 and 28 of the pole pieces 6 and 7, is a palr of co1ls 24 and 25 through which projects the centrally supported armature 17, the ends of which extend between the arms 27-27 and 28-28. Under the influence of the varying currents through the coils 24 and 25,

the armature 17 is caused to vibrate and the auxiliary armature 21 being rigidly attached thereto also vibrates. As the auxiliary armature 21 approaches the auxiliary pole 10, for example, the flux through the poles 10 and 11 tends to vary. Any sllght change in the flux induces M current in the short circuited coils 12 which substantially checks the changes in 'flux There is, therefore, substantially no eifect upon the magnetic circuit controlled by coils '24 and 25. Since the air gap between the armature21 and the auxiliary pole 10, for example, increases at the same time the air gap between auxiliary pole 11 and the armature decreases,there is established a different magneto-motive force between each of the auxiliary poles and the armature and the flux is caused to flow through the high hysteres1's member 26. As the armature 21 vibrates, the flux will therefore flow back and forth through the member 26 and dissipate energy. The hysteresis loss through the circuit in cluding the member 26 is very high while that through the magnetic circuit controlling the armature 17 is practically negligible. The armature 17, is connected to the link 13 by means of a flexible coupling 14, which consists preferably of a narrow strip of hard copper or brass folded back and forth upon YORK, N. 2., A' conroaarron or Y itself. Since one end of the strip 14 is at- I tached to the driving member and the other end to the driven member so that the direction' of the folds will be in'the' direction of the driving force, it provides a joint which is relatively flexible to all vibrations except those in the useful direction and gives a joint in which there is no tendency to rattle. The link 13 maybe connected to a diaphragm 15 supported in a suitable case 20 and provided with a horn 16 such as used in connection with loud speaking receivers. The auxiliary armature 21 rigidly attached at its center to the center of the operatin armature 17 and at right angles thereto, 1s adapted to vibrate between the auxiliary poles 10 and 11. The shaft, or rod, 22 is attached to the armatures 17 and 21 at their intersection. The clamping plates 8' and 9 are provided with supporting lugs 18 and 19 having openings within whlch are suitably secured resilient supports 40 for the rod 22. The support 40 consists preferably of a ring 23 within which is provided a plurality of radially extendingsarms 41, the inner ends of which are secured in a suitable manner,

coincident and their apexes together. This forms 'a sup ort which is very flexible in the oscillatory p ane and rigid in all other planes and one which is free from relatively moving 1. parts requiring ad'ustment.

What is claime is:

1. In a mechanical vibratory system for the transmission of sound wave energy having relatively movable members, a plurality of strips of thin material extending radially between and connecting said members and having their edges free.

2. A mechanical vibratory system for the transmission of sound wave energy having relatively movable concentric members in spaced relation, a lurality of resilient spokes extending radially between and connecting said members.

3. A mechanical vibratory system for the transmission of sound wave energy having a rotatable member, a support therefor comprising a fixed member in spaced relation to said rotatable member, and a plurality of re- 4. A mechanical vibratory systemfor the transmission of sound wave energy having a rotatable member, a support therefor comprising a fixed member, and a plurality of resilient spokes consisting of narrow strips of thin material extending radially from said rotatable member to said fixed member. 5. A mechanical vibratory system for the transmission of sound wave energy, having a rotatable member, a support therefor comprising a fixed member and a plurality of resilient spokes of thin sheet material folded back and forth between said members.

6. A mechanical vibratory system forthe transmission of sound wave energy having a rotatable member, a support therefor comprising a fixed member, and a plurality of spokes of thin sheet material folded back and forth in the form of pyramids, said pyramids having their apexes connected to said rotatable member and there passed to said fixed member.

In witness whereof, I hereunto subscribe my name this 12th day of November, A. D.,

HENRY o. HARRISON.