US1621126A - Tremolo device - Google Patents

Description

March 15 192 7 B. E. MILLS TREMOLO DEVICE Filed March 24, 1926 2 SheetS-Shee`b l.

Mar h l c 5 1927 B. E. MILLS TREMOLO DEVICE Eve/m?.-

2 Sheets-Sheet 2 Qn f wmki Filed March 24 1926 Patented Mar. 15, 1927.

.- lTED TFJS BERTIE E. MILLS, GF OAK PARK, ILLN 01S, ASSIGNOB TO MLLS NOVELTY COMPANY, OF CI-IXCAGO, ILLINOS, A COREORATON OF ELLNOIS.

TREMOLO DEVICE.

Application lcd March 24, 1926.

This invention relates particularly to a tremolo device for stringed-instruments of the viol class in music machines, such as those employing electrical actuating means.

The primary object is to provide an improved means for producing tremolo effects in machines of the character mentioned.

The invention is illustrated in a preferred embodiment in the accompanying drawings, in which- Fig. l represents a broken elevational view of string-tensioning means and pulsatingmeans connected therewith; Fig. l, a fragmentary view of one of the tensioning-levers shown in Fig. 1; Fig. 9., a broken plan view,

partly in section, of the improved pump device and pulsating-means; and Fig. 3. a broken vertical section taken as indicated at line 3 of Fig. 2.

The views may be regarded as somewhatdiagrammatic in their nature.

In the construction illustrated, A designates the neck-portion of a violin, for eX- ample, which is equipped with strings 1 B, tensioning-means for said strings; C, pulsating-means associated with said tensioning-means and comprising individual pulsating-devices for vibrating each of the several tensioning-levers: D, pumping-means actuated by a solenoid D and provided with a conduit D2 which serves all ofthe pulsating-devices; D3, a circuit-controlling device associated with the pump D; E, a manuallyadjusted valve controlling the conduit D2; E', an electro-magnetically controlled valve also controlling the conduit D and F, an electro-magnetic device, controlling the valve E.

The normal tension of the strings l is applied through the tensioning-means B comprising, in the illustration given. a series of individual tension devices, each of which consists of a tension-lever connected with the corresponding string, and a coil-spring of adjust-able tension. There are four tensionlevers corresponding with the four strings of aviolin. Two of the levers, designated 2 and 3, are seen in Fig. l. They have pivotally connected therewith links 2a and 3a. The springs 4 (one shown) are connected at one end by means of such links with the individual levers. At the other end the springs are connected with individual tension-adjusting devices 5 (one shown).

Each string l passes freely over a grooved Serial No. 96,983.

sector la of the corresponding lever and is adjustably secured to the lever by an adjusting device 1b. The adjustment of strings, levers and springs is such that the strings are under normal tension with the levers in horizontal position; and the springs preferably are at an angle of 45 with relation to the plane of the levers. It has been found with such relation of the parts, the levers may be vibrated sufliciently to give the desired tremolo effect without substantially varying the effective turning moments of the springs and levers.

The pulsating-means C comprises a cylinder 6 and ay piston a for each tensioninglever. The piston-rods shown are designated 6b. It will be noted that in the case of the longer lever 3 the connecting rod is pivotally joined to the extremity of the lever at 7, while the link 32 is pivotally joined to the lever at 8. In the case of the lever 2, both the link 2a and the connecting-rod are v connected with the lever by a pivot-pin 9.

It may be noted here that the pistons 6a need not lit closely within the cylinders 6. The cylinders are served with compressed air, or air-pulsations, through individual conduits 10 extending through a block or valve-casing, l()a fitted with controlling valves 10b. The ports 10 are served from a common conduit 11, which is, in effect, a continuation of the conduit D2 leading from the pump D. It is desirable that the tensioning-levers be vibrated rapidly to produce the desired tremolo effect, but the amplitude of movement of each lever preferably is suited to the corresponding string. The low string, for example. requires greater tension-variation than the high string. The amplitude of movement and (if desired) the rate of vibration may be varied to accomplish the desired result.

The valves 10b may be used to regulate the admission, or feed, of air-pulsations from the common conduit l1 to the several pulsating-devices. Thus, notwithstanding a single pumping mechanism serves all the pulsating devices.7 each pulsating device may be regulated to impart the vibrations suited to its particular lever and string.

Again, the valve E may be set to approximately regulate the feed to the conduit 11, and the valve E may be controlled by a switch located at any desired point, as for example on a console iitted with a key manlll) ual. Thus, the valve E may serveas an auxiliary valve, conveniently controlled from any point, to vary the feed of air through the conduit D2 to the passage 11, at will.

The Vpump D preferably is actuated by an electro-magnetic device. The preferred construction and arrangement is illustrated 4as comprising a cylinder 12; a plunge-r 13 i'itted with a piston 13a; the solenoid D encircling or wrapped on the cylinder 12; and

a coil-spring le which serves to retract the piston after it has been actuated .by the solenoid D.

The walls of the cylinder12 may be of non-magnetic material, plunger 13 and piston 13a serve as a magnetic core, or plunger. The parts should be suitably designed to enable the solenoid to actuate the piston during its working stroke, i. e. in moving to the lett-hand end of the cylinder as shown in 3. During this working stroke air is forced in regulated quantity through the outlet port 15 (Fig. 2), past the valves E and E into the conduit D2 and thence to the pulsating-means C. During the working-stroke of the piston, the tension of spring 14 is increased and later the spring retracts the piston.

The left-hand end of the plunger 13, designated 13b, may be of brass or other nonmagnetic material.

The plunger 13 has aprojecting end-portion fitted with a flange 13c which serves to actuate the circuit-controller D3 which controls the circuit 16 of the solenoid D. The circuit 16 may be equipped, also, with a switch 16a which may be located at any convenient point.

In the example given, the solenoid D actuates the pump-piston in one direction and places the spring 14 under sutllcient tension to retract the'piston after the solenoid is de-energized. With such arrangement and operation, the piston, as it approaches the end of its working stroke, throws the switch D3 to circuit-breaking position, and when the piston is retracted the switch is again thrown to the circuit-closing position.

As shown, the switch D3 is mounted on a pivot 17 and is equipped with actuating arms 18 and 19 adapted to be engaged by the flange 13C. The switch has a contact-arm 2O which co-acts Ywith a contact pointl 21 with which the circuit 16 is provided.

The valve E is normally open, or partially open. lt has an actuating arm 22 connected with the movable core 23 of the solenoid F. A compression spring 24 tends to hold the core 23 in the normally displaced position shown in Fig. 2. rlhe solenoid is provided with a circuit 25 equipped with a switch 25L which may be located at any suitable point. Thus, the switch may be at a point remote from the solenoid and the valve if f desired. The

E may be controlled therefrom. By closing the circuit, the solenoid will be energized and caused to draw in the core 26, thus restricting lor closing the passage at the valve E. Y

From the description given, it will be understood that the invention provides for giving an improved tremolo etiect in a very simple manner and bymeans of very simple and readily controlled mechanism.

Obviously, the solenoid D can be inade'to ctuater the pui'np-piston in one or both directions, as desired, the arrangement described bei a prefered arrangement. ln fact, any suitable electro-magnetic device may he employed for actuating the pumppiston, the latter g, l inatically shiit tlie circuit-changer, as Y required.

ln practice, it is preferred to give the piston 6L a fairly close lit within the cylinders 6, and to so operate the pump device that it will pulsate air hack and forth through the conduit .D2 as the piston of the pump device reciprocates. Thus, when the piston moves to the le t, as viewed inllig. 6, air will be forced through the conduit D2 into the passage 11 and serve to elevate 'the pistons and w en the air recedes from the cylinders of the pulin. '-device C, allowing the pistons 6L to escend. The return movement of the pison 13C ot the pump device D may be reguatet. by providing the end of the ,cylinder with'an i a valve 27 for regulating the size of the discharge passage. Thus-therate of the pulsations may be regulated by regulating the movement of the piston 13a.

rl`he foregoing detailed description: has been given for clearness of understanding only, andl no unnecessary limitations should be understood therefrom, but the'appended claims'should be construed as broadly 'as permissible, in view of the prior art.

What l regard as new, and desire to secure CD by Letters Patent, is: Y

1. In combination with a string-tensioning device of a stringed instrument of the viol class, a tremolo-device comprising a pulsating-device connected with said tensioning-device, a pump provided with a conduit serving said pulsating-device, a solenoid serving to actuate said pump, and an electric circuit for said solenoid controlled by said pump.

2. In combination with astring-tensioning .device ofa stringed instrument of the Vviol class, treinolo-device comprising a pulsating-device connected with said tensioning-device, a pump comprising a cylinder and a reciprocating piston, yielding means serving to -actuate said piston in one direction, a solenoid serving to act-nate said piston in the other direction, an electric circuit serving in turn, to autodischarge passage 26 litted with pump-piston is retracted,

for said solenoid, circuit-controlling means actuated by said piston and a conduit leading from said pump anc serving said pulsating-device.

3. In combination with a pulsating-device for actuating a string-tensioning device, pumping means comprising a cylinder equipped with a solenoid, a pump-piston Within said cylinder actuated by said solenoid, a conduit leading from said cylinder and serving said pulsating-device, an electric circuit for said solenoid, and circuitcontrolling n'ieans actuated by said piston.

4. In combination with a pulsating-device for actuating a string-tensioning device, pumping means comprising a cylinder equipped With a solenoid, a pump-piston Within said cylinder actuated by said solenoid, a conduit leading from said cylinder and serving said pulsating-device, an electric circuit :tor said solenoid, and an oscillating circuit-maker and breaker actuated in both direct-ions by said piston.

5. In combination with a string-tensioning lever, a pulsating-device, a pump serving said pulsating-device and having a reciprocating piston, and an electro-magnetic device serving to actuate said piston and having a circuit controlled by the movements of said piston.

6. In combination with string-tensioning nieans and co-acting pulsating-means, a pump having a conduit serving said pulsating-means, a valve controlling said conduit, and an electro-magnetic device for actuating said valve.

7. In combination With string-tensioning means and co-acting pulsating-means, a pump having a con-duit serving said pulsating-means and having a reciprocating piston, a valve controlling` said conduit, and electro-magnetic devices tor actuating said piston and said valve.

8. In combination with string-tensioning means and co-acting pulsating means, a punip having a conduit serving said pulsating-means and having a reciprocating piston, a valve controlling said conduit, an electro-magnetic device serving to actuate .said piston and controlled by said piston, and an independent electro-magnetic device controlling said valve.

9. In combination with string-tensioning levers and separate pulsating-devices connected therewith, valve-controlled conduits leading to said pulsating-devices, and a pump .serving all of said conduits.

10. In combination with .string-tensioning levers and separate pulsating-devices connected therewith, valve-controlled conduits leading to said pulsating-devices, a pump having a. conduit serving all said lirstnamed conduits, and a valve controlling said second-mentioned conduit.

11. In combination with string-tensioning levers and separate pulsating-devices connected therewith, valve-controlled conduits leading to said pulsating-devices, a pump having a conduit serving all said irst-nanied conduits, a manually adjusted valve gua-rding said second-mentioned conduit, and also an electro-magnetically controlled valve controlling said second-mentioned conduit.

BER'IIE E. MILLS.

Images