US2321366A

US2321366A - Electric carillon

Info

Publication number: US2321366A
Authority: US
Publication date: 1943-06-08
Anticipated expiration: 1960-06-08

Description

June 8, 1943. G, w. DEMUTH 2,321,366

ELECTRIC CARILLON Filed Dec; 20 1940 Imventor Galan WDemu/Z'Lh (Ittomcg Patented 'June 8, 1943 ELECTRIC CARILLON Galan W. Demuth, Moorestown, N. J assignor to Radio Corporation of America, a corporation of Delaware Application December 20, 1940, Serial No. 370,936

3 Claims.

This invention relates to electric carillons and a method of tuning the same.

In electric carillons the vibrating element is usually a bar or rod of steel which is struck by a hammer to cause it to vibrate, and to produce by means of a magnetic pick-up device corresponding electrical variations which are transmitted through an amplifier to a loudspeaker.

There is frequently disagreement as to the tone quality and pitch of these devices. Even when the vibrating reeds or rods are tuned accurately by means of an oscillograph, they may still sound sharp to some while they sound flat to others due to the individual variations in sensitivity of the human ear to the higher harmonics. For example, to a person whose hearing is deficient in the higher frequencies, the reed may sound flat when the apparent flatness is merely due to their inability to hear the higher frequencies produced, while to a person with unusually acute hearing in the higher frequencies, a given reed may sound sharp due to the predominance of the higher overtones. One characteristic of vibrating reeds which exaggerates this effect is that the higher overtones are not true harmonics of the fundamental or even of the apparent fundamental, and therefore the relative predominance of these overtones may noticeably affect the apparent pitch.

In the apparatus and method of the present invention, I vary the relative preponderance of the higher overtones in the vibration of the reed and thereby change the apparent pitch of the reed without changing the actual pitch thereof.

In my application Serial No. 248,542, filed December 30, 1938 (RCV Docket 6515), I described and claimed an improved striking and pickup mechanism for an electric carillon, and in my application Serial No. 338,088, filed May 31, 1940 (RCV Docket 7645) I described an improved type of vibrating reed and method of tuning the same. The present invention is an improvement on both of those applications. Its outstanding characteristic is that after the reed is accurately tuned, its apparent pitch is changed.

One object of the invention is to provide an improved electric carillon.

Another object of the invention is to provide an improved method of changing the apparent pitch of an electric carillon.

Another object of the invention is to provide an improved method of and apparatus for voicing an electric carillon.

Other and incidental objects of the invention will be apparent to those skilled in the art from a reading of the following specification and an inspection of the accompanying drawing in which Figure 1 is an end View of the mechanism of an electric carillon constructed substantially in accordance with the latter of my applications above referred to and illustrating the application of the present invention thereto;

Figure 2 is a view of the supporting plate taken from the right-hand side of Fig. 1 and further illustrating the manner in which the invention is applied to the electric carillon, and

Figure 3 is a plan view taken from the top of Fig. 2 and illustrating the relation between the several vibratable reeds.

Referring first to Fig. 1, the key In is pivoted so as to swing the arm II toward the'reed I4. When the key In reaches the bottom of its travel, the hammer I2 swings away from the arm II on the resilient member I3 and strikes the reed I4. The reed I4 is provided with a notch I5 which serves to tune two of the overtones of the reed into accurate harmonic relation as described and claimed in my said application Serial No. 338,088, thereby producing an apparent fundamental which is the fundamental frequency to which those two overtones have an accurate harmonic relation.

The reed I4 is mounted upon the massive block I6 which also supports the electromagnetic pickup coil I! by means of the bar I8 which is or contains a permanent magnet as described in the earlier of my said applications. The bar I8 is rigidly and permanently secured in and to the block I6 so that it is not adjustable in relation to the reed I4. The reed I4 is similarly secured to the block I6 by a screw 22. The block I6 is mounted upon a supporting plate I9 by means of screws 20 which pass through the adjusting slots 2I in the plate I9.

These adjusting slots 2I permit the bodily movement of the assembly including the block I6, the coil H, the magnet member I8 and the reed I4 vertically in relation to the hammer I2.

If the hammer I2 should, for example, strike the reed I4 at the location indicated by the arrow 24, a certain tone would be produced having a certain proportion of higher overtones. If the screw 20 is loosened and the assembly with the block I6 is raised so that the hammer strikes the reed at the point indicated by the arrow 23, then the higher overtones produced will be of smaller amplitude and there will be fewer of the very high overtones. Conversely, if the assembly I4, I6, I1, I8 is moved downwardly and secured in the lower position by the screw 20 so that the hammer I2 strikes the reed at the point indicated by the arrow 25, then the higher overtones will be produced with greater amplitude and audible overtones will be produced of higher frequencies not audible under the other two conditions.

What is claimed is:

1. An electric carillon including a striking member, an assembly including a massive supporting member, a vibratable reed provided with a notch defining the pitch of its overtones and carried on said supporting member and a magnetic pickup carried in fixed relation to said supporting member, and means for bodily adjusting said assembly in relation to said striking member for changing the apparent pitchof the reed by changing the intensity ratios of the overtones.

2. An electric carillon including a striking member, an assembly including a massive supporting member, a vibratable reed provided with a notch defining the pitch of its overtones and carried on said supporting member and a magnetic pickup carried in fixed relation to said supporting member, and means for adjusting said reed longitudinally in relation to said striking member Without changing the relation of the reed to the remainder of said assembly for changing the apparent pitch of the reed by changing