US1009798A - Producing musical tones. - Google Patents

Description

M. L. SEVERY & G. B. SINCLAIR.

PRODUCING MUSICAL TUNES.

APPLICATION FILED 113.19, 1910.

1,009,798. Patnted Nov. 28, 1911.

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PBODTU'CIkG MUSICAL TONES.

Specification of Letters Patent;

Patented Nov. 28, 1911.

To all whom it may concern:

Be it known that we, MELVIN-L. Seven, of Arlington Heights, in the county of Middlesex and Commonwealth of Massachusetts, and GEORGE B. SINCLAIR, of Medford, in said county and Commonwealth, both citizens of the United States,have invented certain new and useful Improvements in Processes of Producing Musical Tones, of which the following is a specification.

Our invention has for its object the production of musical tones in musical instruments embracing sonorous bodies, and electromagnetic means for their actuation;

the especial features of our invention com- Fig.2 is a cross section 0 the same. Fig. 3

is a cross section. on a larger scale of a similar means but adapted for carrying into effect added steps in our process.

In Fig. -.-1 is illustrated a considerable number of sonorous bodies, as strings 1, which are designed to be tuned to the successive notes of the musical scale. Each strin is provided with an electromagnet2 to w ich electric pulsations are to .be transmitted for the magnetic actuation of such string; and each electromagnet is inv circuit with a pulsation (producing means, all which means are rotate commensurately with each other, as by being mounted on a common shaft 3. In previous electrical musical instruments made by us, as those set forth in our companion application No.'443,912, we take a continuous current, from anysuitable source, and transform the same into pulse tions suitable for the various tuned sonorous bodies, means of current interrupting devices.

or alternating currents adapted for the dlfierrotors,

ot erwise occur, and consequently dn this process, however, we generate de novo the desired pulsato ent electromagnets and strings. Each such current generator is hereshown as consisting of. an electromagnetic spool having heads 4 'and'windings'v 5,.said windings bein in circuit with any suitable source as 6, in ig. 2. Said heads are formed withv peripheral teeth 7 which by moving in the fields of the pole pieces 8, induce intermittent or ulsatory alternating currents in the windings 9 whlch are immediately shared in by the connected electromagnets 2. I

By having the teeth 7 on the spools, or

far enou h apart, the currentpulsations will have dead intervals between them long enough to permit the strings to recede from their electromagnets and be a 21in attracted thereto; but in case the sald teeth are so close together as not to allow such dead intervals, then it is essential to polarize each electromagnet, as illustrated in Fig. 3. One method of such polarization consists in elongating the core of'the magnets 2, and mounting thereon windings 10 wired to a source of direct current 11. Then inasmuch as each currentalternation consists of one flux in onedirection, and another in the re verse direction, one half ofleach alternation will'be of like polarity in the electromagnet' 2 to that of the windings 10 and W111 double the magnetic efiect of the magnet;

while the other half will beof uirlike polarity, and will neutralize the polarity of the instance must have a number of teeth 7 1n its I heads 4- whichwill be incommensurate with the number of teeth on the heads 4 of the rotor associated with the string C. We sur-.-

mount this difficulty by formin a blank space 12 at the section of the eads per1 hery where the fractional tooth would separate each group of correctly time im ulsegcnerating teeth with an interval di ering cm the remaining teeth. I

As thus far described, our process will consequentl be seen to consist in generating eleotriclty in a multiplicity of pulsations of a frequency equal to the vibrations of a tuned sonorous body, the pulsations being separated into groups by the interposition of an interval differing from the vibrational interval of said body. It will also be seen that we impress upon the electromagnet controlling a tuned sonorous body electric pulsations equal in frequency to the vibrations of such body, and also electric pulsations unequal thereto, the former being so much more numerous as to practically overwhelm and.

render negligible the latter pulsations.

in the apparatus illustrated in Fig. 3, we set'forth a process whereby we superpose upon the electromagnet 2 a plurality of simultaneously produced electric pulsations, and consequently affect its associated sonorous body 1 with a correspondingly greater strength. In doing this the rotor heads 4 are each surrounded by pole pieces 15 equal in number to the teeth 7 and separated from each other by angular spaces equal to those between the teeth. These pole pieces are shown as arranged in two groups, but we do not restrict ourselves to this number, the windings 16 of each roup being wired together tandem, but t ey may be wired in multiple. Inasmuch as when the abnormal space 12 is presented toward either said group, more or less ofthe pole pieces thereof will not be in phase with juxtaposed teeth, we arrange to cut out of the circuit to the electromagnet 2 each said group when said abnormal space reaches it, and switch into the circuit the group from which said space has just departed. In this manner we superpose upon the elcctromagnet a number of simultaneous current pulsations substantially equal to one half of the teeth. To thus cut in and out said pole piece windings 16, the shaft 3 is provided with a semi-circular contact 1'? having in position to touch the same two oppositely located stationary brushes 18, 19. Each brush is wired to .one terminus of one group of windings 16, while the opposite terminus of each group is wired to the electromagnet 2; and the shaft 3 has a. brush 20 wired to said electromagnet. As the rotor revolves, .said contact 17 automatically cuts out one group of windittgs and switches in the other group, and so keeps the electromagnet constantly supplied with vigorous resultant pulsations, separated into groups as shown by phase displacements.

What we claim as our invention and for which we desire Letters Patent is as follows, to

1. The herein described process of educing a musical tone, which consists in generating electricity in a multiplicity of series of recurrent cycles of pulsations, most of said series of cycles having in each cycle thereof a plurality of frequencies of pulsations the majority of said pulsations being in each case of the vibrational frequency of an associated sonorous body, but the remainder of said pulsations being of a different frequency and causing said pulsations to vibrate said sonorous body.

'2. The herein described method of educing a musical tone, which consists in generating electricity in cycles of current pulsations, all but a few of the pulsations of each cycle being equidistant in time each from its preceding and following pulsations, but some thereof being separated from certain of their associated ulsations b intervals different from those intervening etween the majority of said pulsations, and impressing said pulsations upon means adapted to vibrate a sonorous body.

3. The hereindescribed method of educing a musical tone, which consists in generating electricity in cycles of impulses most but not all of which im ulses in each of most of the cycles are equidistant from each other in point of time, and impressing said impulses upon means adapted to vibrate a sonorous body.

4. The herein described method of educing a musical tone, which consists in generating electricity in a plurality of trains of impulsesall but a few of the impulses in each train being equidistant from each other in point of time and the impulses of some trains eing of a frequency per unit of time incommensurate with that of some of the other trains, the said trains being generated b rotary motions commensurate with each other, and impressing said impulses upon means adapted to vibrate a sonorous body.

5. The herein described method of educing a musical tone which consists in generating a plurality of series of electric impulses,

some of the alternations in some of the series being out of tune relative to their neighboring impulses, each said series havin a. majority of its impulses timed to the vibrations of a note of the musical scale and the frequencies of the majority of the impulses composing some of the series being incommensurate with the frequencies of a majority of the impulsescomposmg some of the other series, and impressing said impulses at will Epm means adapted to vibrate a sonorous 6. The herein described process of producinga musical tone, which consists in generating electricity in pulsations equal in frequency to the vibrations of a sonorous body, and also generating other electrical pulsations of a different frequency, and impressing both kinds of pulsations upon said sonorous body, the proportion of the first named pulsations being in suiiicient excess over that of the other pulsations as to overpower them and render negligible their effect.

7. The herein described process of educing a musical tone, which consists in generating electricity in a multiplicity of pulsations of a frequency equal to the vibrational frequency of a sonorous body, the said pulsainvention, We have hereunto set our hands tions being separated into groups by the inthis 27th day of January, 1910. terposition of an in erval differing from the M ICLVIN L. SEVERY. vibrational intervals of said sonorous body, GEORGE B. SINCLAIR. 5 and utilizing the said pulsations to vibrate \Vilnessvs:

said sonorous body. A. B. UIIL-Ul,

In testimony that we claim the foregoing ,nAmncs GARRISON.

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