US655557A - Sound recording and reproducing machine. - Google Patents

Description

No. 655,557. Patented Aug. 7,1900. E. R. JOHNSON.

SOUND RECORDING .AND REPBODUCING MACHINE.

ion filed Aug. 23, 1898.)

(No Model.)

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SOUND RECORDING AND REPRODUCING MACHINE.

SPECIFICATION forming part of Letters Patent No. 5,557, dated August 7, 1900.

Original application filed June 1, 1897, Serial No. 639,028. Divided and this application filed August 23, 1898. Serial No.

' 689,291. (No model.)

To [LZZ whom it may concern.-

Be it known that I, ELnRIDen R. JOHNSON, a citizen of the United States, and a resident of the city of Philadelphia, State of Pennsyl- Vania, have invented certain new and useful Improvements in Sound Recording and Reproducing Machines, of which the following is a'full, clear, and exact description, reference being had to the accompanying drawings, forming part of this specification.

My invention relates to certain improvemen ts in sound recording and reproducing machines, and has for its object to simplify and improve the construction of what is commonly known as the sound-box and parts pertaining thereto, my present application being a division of application filed by me June 1, 1897, Serial No. 639,028.

In the accompanying drawings, Figure l is a perspective view of a sound recording and reproducing device constructed in accordance with my invention. Fig. 2 is a sectional view of Fig. 1. Fig. 3 is an exaggerated sectional diagram illustrating the diaphragm and the parts adjacent to its periphery.

Referring to the drawings, A represents the tubular section of the diaphragm-supporting frame connected at one end to a recessed diaphragm-holding disk B and at its opposite end leading and connected directly orindirectly to a mouthpiece, trumpet, or similar soundconveying device. In the front face of the disk B is formed a recess b, having a step or flange c, on which is placed a ring d, of soft rubber or other suitable yielding material. In front of this ring the diaphragm D is adjusted in position, and on the outer face of the diaphragm, hardly or slightly in contact therewith, is placed a second similar ring 0?, which is confined in place by the disk E, secured by screws e, as illustrated in Fig. 1, or by other suitable means to the recessed portion B.

It will be noted, as more clearly shown in Fig; 3, that. the periphery of the diaphragm is out of contact with the inner peripheral walls of the recess, preferably to an extent of about four one hundredths of an inch. It is also clear, as particularlyillustrated in this figure, that the faces of the diaphragm near its periphery are practically out of obstructive contact with the faces of the adjacent rubber rings, or the contact, if any, is so slight as not-to prevent the diaphragm under the impulses of the sound-Waves from vibrating practically evenly throughout its entire area.

In a recess g, formed in the peripheries of the disks B and E, is fitted the stylus-bar holder or spring-support H, having the springplate portion h formed of the desired thickness and adapted to be secured at one end to the bar I. The spring-support H comprises the plate portion 71. and may have adapted thereto the fixed block-like portion h and the adjustable block it. The distance between the said blocks and thickness and width of the plate govern the freedom of movement of the stylus-bar I. The support H is secured to the disk B by any suitable means, such as that illustrated in Fig. 1 or in Fig. 2. The enlargement of the orifice in the plate portion 77?, through, which the screw g passes, will obviously permit of a slight lateral ad'- justment of the parts. In Fig. 1 the orifice through which the screw g passes is preferably slightly enlarged, which will permit of slight adjustment. In Fig. 3 the orifice through whichthe screw 9' passes is shown as considerably enlarged to permit a more-extended adjustment.

Referring to Fig. 2, plate It is of considerable length and slotted at it for the passage of the securing-screw g. The plate It passes through a slot 77., formed in the center of the block h, which latter is also provided with a slot 72. in line with the slot h for the passage of the securing-screw g; In adjustmentfor the lower or higher notes'the relative positions of the stylus-bar and diaphragm should not be altered, and the plate h therefore'remains in the same position at all times, while the slotted block it is moved toward and from the block h, so as to decrease or increase the length of the plate between the adjacent edges of the blocks h h and then firmly secured in position to bind the plate, the effect when adj usted being substantially the same as though "the block 71. were formed integral with such plate. It is clear that the plate 72?, having the elongated slot It", as shown in Fig. 2, may, if desired, be also adjusted lengthwise in the block h to accomplish the same purpose,

slightly-enlarged head i, which is connected to the diaphragm by a slightly-elastic cement i. In adjusting the stylus-bar to the diaphragm considerable care should be exercised.

At a suitable point in the length of the stylus-bar is a guard M, secured by screws m to the flange or plate in front of the diaphragm and having at its center a slot on, through which passes the stylus-bar I, the distance between the side and bottom walls of the slot and the sides of the stylus-bar being preferably about one one-hundredth of an inch, so that lateral movement of the stylus-bar to any greater extent than what is approximately the normal vibratory movement is prevented, and thus the bar is prevented from being torn from the diaphragm by an accidental knock or jar. The vibration of the diaphragm beyond the normal limits is prevented in one direction by the bottom wall of the slot m and in the opposite direction by the adjustable stop-screw n, screwing into the disk E at a point within the slot and immediately under the stylus-bar.

I have discovered that to obtain the best results the diaphragm should move substantially as a whole in both recording and reproducing and not be rigidly confined at its peripheries in such a manner as to make it simply a round spring in which the vibratory movement is greatest at the center or point of contact with the stylus.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, is-

1. In a sound recording and reproducing machine, ayielding stylus-bar support secured at one end to a fixed point and its opposite end to the stylus-bar, said support having an enlarged head at the point of connection with the stylus-bar, said yielding suph, provided vertically through said block to allow of lateral adjustment upon the securing-screw, substantially as described.

3. In a sound recording and reproducing machine, the combination of the diaphragmsupporting case, a diaphragm therein, a stylus-bar secured at one end to the center of r the diaphragm, a-slotted guard fitting over said stylus-bar, an adjustable set-screw pro j ecting from the diaphragm-case immediately under the stylus-bar, said set-screw and guard being adapted to limit the range of vibratory and lateral movement of said stylus-bar.

4. The combination of the diaphragm-support provided with a recess for the reception of the diaphragm, a diaphragm of a diameter less than the diameter of the recess, a stylusbar having one end secured to the center of said diaphragm, and a slotted guard fitting around said stylus-bar and adapted to limit the range of movement of said stylus-bar.

5. In a sound recording and reproducing machine, the combination of the diaphragmsupporting case, a diaphragm therein,'disk, E, a stylus-bar secured at one end to the center of the diaphragm, and a slotted guard, M, secured upon the disk, E, having a central slot, m, adapted to the passageof the stylusbar and to limit abnormal movement of the stylus-bar, substantially as described.

6. In a sound recording and reproducing machine, a yielding stylus-bar support secured at one end to a fixed point and its opposite end to the stylus-bar, said support having an enlarged head at the point of connection with the stylus-bar, said yielding support being reduced in thickness throughout the remainder of its length to properly yield under the impulses of the sound-waves to retain the diaphragm in its normal position in the sound-box when at rest, substantially as described.

Inwitness whereof I have hereunto set my hand this 12th day of August, A. D. 1898.

ELDRIDGE R. JOHNSON.

Witnesses:

HORACE PETTIT, BENJ. F. PERKINS.

ICC

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