US1425944A

US1425944A - Sound recording and reproducing instrument

Info

Publication number: US1425944A
Application number: US479380A
Authority: US
Inventors: Clifton William Ernest; Ewart John Sturton
Original assignee: CLIFTOPHONE Ltd
Current assignee: CLIFTOPHONE Ltd
Priority date: 1921-06-21
Filing date: 1921-06-21
Publication date: 1922-08-15
Anticipated expiration: 1939-08-15

Description

W. CLIFYON AND). S. EWART. SOUND RECORDING AND REPRODUCING INSTRUMENT.

APPLICATION FILED JUNE 21. 1921.

1,42 5,944. Patented Aug- 15, 1922.

To all whom it may concern:

Be it known that we, WILLIAM ERNEST CLIFTON and J OHN STURTON EWART, subjects of the King of England, residing in Nottingham, England, have invented certain new and useful Improvements in Sound Recording and Reproducing Instruments, of which the following is a specification.

This invention consists in improvements in or relating to sound-recording and soundreproducing instruments for use with gramophones and like machines. The type of instrument to which the present invention relates is that in which a flexible diaphragm is carried in a casing, hereinafter referred to as the sound-box, and the diaphragm is firmly connected to one end of a lever or stylus-bar pivotally mounted on the soundbox so that it can oscillate in a plane at right-angles to the diaphragm. The other end of the lever is formed to receive a needle the point of Which serves either to record on a plastic body vibrations imparted to thediaphragm or, in reproducing, the point of the needle is oscillated by the record to transmit vibrations to the diaphragm. The object of the present invention is to provide means for articulating the stylusbar to the sound-box .in an improved manner so that in recording on a record surface the vibrations will bemore accurate and clear than heretofore and in reproducing the sounds produced will be clearer, more pure in tone, and more free from noises commonly known, inter alia, as jarring or .shocks or needle-scratching than is possible with known constructions of similar instruments.

According to the present invention the means for articulating a stylus-bar comprise one or more spring blades each of which is connected by its ends respectively to the sound-box casing and to the stylus-bar at aposition intermediate in the length ofthe latter, and is so disposed that its line or region of flexure is substantially in the plane of the diaphragm. In one form the spring blade or blades are themselves parallel with,

or substantially in, the plane of the diaphragm.

Preferably, however, the blade or set of blades above described is combined with a second blade or set disposed in a plane at right-angles to the plane of the first blade or set and to that of the diaphragm. *In

Specification of Letters Patent. Application filed .Tune 21, 1921.

Patented Aug. 15, 1922. SeriaI No. 479,380. r

such a construction the stylus-bar is conveniently formed with a laterally-projecting abutment disposed adjacent to the rim of the sound-box casing and the two spring lades or sets of blades are so operatively connected between the abutment and the sound-box casing that the lines or regions of flexure of all the blades are substantially in the plane of the diaphragm.

ne preferred form of the invention will now be described with the aid of the accompanying drawings, in which lgure l is a front elevation of the stylusbar and its articulating means with the sound-box casing shown in chain lines;

Figure 2 is a perspective detail view of the1 articulating means on an enlarged scale; an

Figure 3 shows a modified form of soundbox and stylus-bar.

Like reference numerals indicate like parts in the two figures of the drawings.

The stylus-bar 1 is, at a point intermediate in its length, formed with an abutment 2 adapted to lie substantially parallel with and in register with the edge of the sound ox casing, which latter is indicated at 3. The abutment 2 has an upturned extremity 4 and from the abutment projects what is virtually part of the stylus-bar in the form of a needle-socket 5. The other end of the stylus-bar 6 is rigidly connected to the diaphragm.

A blade or strip 7, which is adapted to be secured by screws 8 to the sound-box casis connected with the abutment 2 by means of two spring blades or strips 9 which are so' disposed in relation to that they will be substantially in the plane of the latter. Other spring blades 10, at right-angles to the blades 9, are operatively connected between the upturned lug 4 and a lug 11 forming part of the plate 7 and normally parallel with the lug 4. The dimension and disposition of the blades 10 is such that their normal region of flexure is substantially in the plane of the diaphragm. It will be appreciated also that the normal region of 'flexure of the blades 9 is in the same plane so that both sets of blades are normally flexed in substantially the same plane which is that of the diaphragm. i

The needle-socket 5 is so disposed that a needle 12, secured therein by the usual screw the diaphragm l3,'is disposed substantially centrally in the plane of the diaphragm and the blades 9.

It is found with this construction that end pressure on the needle 12 is received as end thrust on the blades 9 normally causing no flexure of the latter. Should, however, comparatively violent end shocks be imparted to the needle such as, and sufficient, to cause fiexure of the blades .9, the blades 10 tend to resist and to take up such undue shocks. The normal sound vibrations which oscillate the stylus-bar in a plane at right-angles to that of the diaphragm are permitted readily by the flexing of both sets of spring. blades.

In Figure 3 the sound-box 3 is shown as operating with its circular face opposed to or facing the record surface 14 as distinct from the form of sound-box illustrated in Figure 1 in which the circular-face of the sound-box is in a planeat right-angles to the surface of the record. In Figure 3 the stylus-bar 1 is formed with an equivalent abutment 2 and upturned extremity 4 but the needle socket 5 is now substantially in prolongation of the abutment 2. As in the previously described construction, two sets of spring blades 9 and 10 are provided to articulate the stylus-bar to the plate 7 but the needle will now be substantially in the plane of the blades 10 instead of that of the blades 9 as abov described.

With the construction shown in Figure 3, it is found that all tendency which the sound-box of Figure 1 has to be oscillated about an axis approximately in the plane of the sound-box, is now eliminated, with the result that still further improvements in tone and clarity of the sounds produced is obtained. Th tone-arm 15 will conveniently be formed as an integral portion of, orv

rigidly secured to, the sound-box casing.

As both sets of blades are firmly secured in the parts to which they are attached, for example by silver-soldering or other preferred means, extraneous noise such as is often apparent where pivot-pins or like devices are employed for articulating the stylus-bar is eliminated. Such noises accrue, amongst other reasons, from the friction of the needle-point on the record and with pivot-pin or like articulation of the stylus-bar slight movement of the pivots from this cause and unevennesses in the surface of the record are transmitted to the diaphragm a jarring or scratching noise. Such noises are eliminated by the present construction and the pure tones produced by the desired sound vibration of the diaphragm remain substantially unimpaired by extraneous and objectionable noises.

If desired, only one of the sets of spring blades may be employed as the sole means of articulation of the stylus-bar, conveniently a set such as 9. Insuch a form it is essential that the region of flexure of the blades should be in, or substantially in, the plane of the diaphragm.

What we claim as our invention and dcsire to secure by Letters Patent is 1. Means for articulating a stylus bar to the casing of a sound box of the type described, said means comprising at least two spring blades whereof one blade is disposed in a plane at right angles to the plane of the other blade and one of the blades is arranged in or substantially in the plane of the diaphragm, an operative connection between one end of each blade and the sound box casing and another operative connection between the other end of each blade and the stylus bar at a position intermediate in the length of the latter.

2. Means for articulating a stylus bar to the casing of a sound box of the type 'described, said means comprising two sets of spring blades whereof the blades of one set are disposed in a plane at right angles to the plane containing the blades of the other set and the blades of one set are arranged in or-substantially in the plane of the diaphragm, an operative connection between one end of each blade and the sound box casing and another operative connection between the other end of each blade and the stylus bar at a position intermediate in the length of the latter.

3. Means for articulating a stylus bar to the casing of a sound box of the type described, said means comprising at least two spring blades whereof one blade is disposed in a plane at right angles to the plane of theother blade with one ofthe blades arranged in or substantially in the plane of the diaphragm, and the two blades are so arranged that each crosses the other in a plane which bisects or approximately bisects it, an operative connectlon between one end of each blade and the sound-box casing and another operative connection between the other end of each blade and the stylus bar at a position intermediate in the length of the latter.

4;. Means for articulating a'stylus bar to the casing of a sound box of the type described, said means comprising at least two spring blades whereof one blade is disposed in a plane at right angles tothe plane of the other blade, a stylus bar formed near its outer end with a laterally projecting abutment disposed adjacent to the rim of the sound box casing, an operative connection between one end of each of the blades and the sound box casing, and another operative connection between the other end of each' blade and said abutment such that the two blades cross one another at aposition which is substantially in the plane of the diaphragm.

5. Means for articulating a stylus bar formed with a needle socket to the casing of a sound box of the type" described, said means comprising at least two blades whereof one blade is disposed in a plane at right angles to the plane of the other blade, an operative connection between one end of each blade and the sound box casing, and another operative connection between the other end of each blade and the stylus bar,

said operative connections being such that one of the blades is contained in or approximately in a plane which will contain also the axis of the needle when in said needle socket.

6. Means for articulating a stylus bar formed with a needle socket to the casing of a sound box of the type described, said means comprising at-least two spring blades whereof-one blade is disposed in aplane at right angles to the plane of the other blade, an operative connection between one end of each blade and the sound box casing, and another operative connection between the other end of each blade and the stylus bar, the said operative connections being such that one of the blades is contained in or approximately in a plane which will contain also the axis of the needle. when in said needle socket, said plane being at right angles or approximately at right angles to the plane of the diaphragm.

7. Means for articulating a stylus bar having a needle socket to the casing of a sound box of the type described, said means comprising two pairs of spring blades whereof the blades of one pair are disposed -in a plane'at right angles to a plane containing the other pair, an intermediate member adapted to be secured to the sound box casing, an operative connection between one end of each of the blades and the stylusbar, and another operative connection between the other end.of each of the blades and said intermediate member, said operatermediate member, said when in said needle tive connections being such that each pair of the blades crosses the other pair at a position which substantially bisects the blades of said other pair, and the plane of one pair of blades is in or substantially in plane of the diaphragm whereas the plane of the other pair of blades is in or substantially in a plane which will contain the axis of the needle when in said needle socket.

8. Means for articulating a stylus bar having a needle socket to the casing of a sound box of the type described, said means comprising two pairs of spring blades whereof the bladesof one pair are disposed in a plane at right angles to a plane containing the other pair, an intermediate member adapted to be secured to the sound box casing, an operative connection between one end of each of the blades and the stylus bar, and another operative connection between the other end of each of the blades and said inoperative connections being such that each pair of the blades crbsses the other pair at a position which substantially bisects the blades of said other pair, and the plane of one pair of blades is in or substantially in the plane of the diaphragm whereas the plane of the other pair of blades is in or substantially in a plane which will contain the axis of the needle socket, andis at right angles or substantially at right angles to the plane of the diaphragm.

In testimony whereof we have signed our names tothis specification in the presence of two subscribing witnesses.

\VILLIAM ERNEST CLIFTON.

JOHN STURTON EWART. lVitnesses:

CHAs. L. NORDON,

ALFRED HORNEB.