US1490750A - Reproducing and transmitting device - Google Patents

Description

April 15, 1924. I

A. P. PlNKLER REPRODUCING AND TRANSMITTING DEVICE Filed Feb. 18, 192] 2 Sheets-Sheet l April 15 1924- A. P. PINKLER RBPRODUCING AND TRANSMITTING DEVICE Filed Feb 18.

192-1 2 SheetsSheet 2 I I I t l I b H Patented Apr. 15, 1924.

UNITED STATES PATENT OFFICE.

REPRODUCING AND TRANSMITTING DEVICE.

Application filed February 18, 1921.

To all whom it may concern:

Be it known that I, ARTHUR P. PINKLER, a citizen of the United States, and a resident of Ridgefield, New Jersey, have invented certain new and useful Improvements in a Reproducing and Transmitting Device, of which the following is a full, clear, concise, and exact description.

This invention relates to improvements in reproducing and transmitting devices, and particularly to an electrical device for reproducing and transn'iitting musical sounds from a phonograph record.

It is the object of this invention to produce a device of the class described which faithfully reproduces and transmits musical sounds, which is of light but solid construction. and which may be readily assembled.

Vith this object in view, an electrical transmitter is provided and comprises comminuted conducting material, such as granu lated carbon, for varying the resistance of an electrical transmission circuit. In order to prevent the packing of the carbon granules, one feature of the invention provides for a carbon granule chamber which is moved or vibrated to create the desired resistance variations. Due to this arrangement, continuous contact is insured between the carbon granules'and the electrodes forming the terminals of the electrical transmission circuit, and the distort-ion ofthe musical sounds is prevented.

In accordance with another feature of this invention, a movable electrode and a carbon granule chamber are comprised in a mechanical unit, and the unitis vibrated to control the resistance of the transmission circuit.

According to a further feature of the invention, the transmitter is com osed of two carbon granule chambers, eac having a cooperating stationary electrode, a movable electrode being provided in common for the two chambers. Preferably, the movable electrode serves as a partition between the two chambers, and the unit formed by these three elements is vibrated between two stationary electrodes.

These and other features of the invention will more clearly appear from the following description of a preferred embodiment of the invention, and the appended claims.

The drawings represent various views of a. reproducing and transmitting device. Fig. 1 is a front view of the device; Fig. 2

Serial Np. 445,935.

moved; Fig. 4 is a sectional side view; Fig.

5'is a perspective view of the telephonic element or transmitter; Fig. 6 is a sectionalview along lines 6-6 of Fig. 4; Fig. 7 is a sectional view along lines 7-7 of Fig. 5; and Fig. 8 is a diagram of the transmission circuit.

The transmitter, which is to set up variations of current in accordance with the markings of an associated phonograph record of the well known lateral or vertical type, is provided within a casing 1 having removable front and rear covers 2 and 3, and provided at its top with a screw 4 and thumb-nut 5 by.means of which the device may be attached to a phonograph arm in the usual manner. A recessed plate or support 6 is held within the case 1 by means of screws 7-7.

The mechanical reproducing element is provided at the bottom of the casing l and comprises top and bottom plates 10 and 11, and a vibratory member or reproducer 12 within a recess of which a stylus 13 may be secured by means of a thumb screw 14. The plate 11 is fastenedto the plate 10 by means of screws 15, and plate 10 is fastened to the casing 1 and support 6 by means of lugs 16 and 17. The lower ends of lugs 16 and 17 are wedge shaped and form knife-edge pivots for the top portion of reproducer 12, engaging grooves 18 and 19 therein. The top of reproducer 12 projects through an opening 20 in plate 11 within the space enclosed by plates 10 and 11, and is seated on rubber strips 21, 22 provided on plate 11 adjacent to opening 20.

The transmitter comprises three disk shaped carbon electrodes 30,31 and 32. The electrode has a central opening through which a screw 33 projects and is received within a sleeve 34. The sleeve 34 projects through an aperture of, a bridge 35 fastened to support 6 by means of screws 36, 36, but insulated therefrom by washers 37-37 of any suitable material. The electrode 30 is held stationary by means of a screw 38 projecting through the bridge 35 and engaging the sleeve 34. The electrode 32 is similarly stationed onthe other face of support 6. v

The electrode 31 is located between the two stationary electrodes 30- and'32, and'is held around its perifery within grooves of metal strips 41 and 42. The strips 41 and 42 are securely held together' at their ends by rivets 43 or other suitable means, the central portions of these strips being bent to form a pocket or circle within which the electrode 31 is located. A rib or corrugation 44 runs along the outer surface of each strip. On the inner surfaces of these strips, the ribs serve as the mentioned groovesAO. The strips 41 and 42 may be made of relatively light material and structure that receives the necessary stifi'ness.

fromthe ribs. Bearings 45 providedat the upper ends of the strips 41, 42 are engaged by pivots 46 projecting within the recessed portion of the support 6. These serve as the upper pivot of the transmitter. A wire or arm 47 secured between the lower ends of strips 41 and 42 terminates in a hook-48 engaging a wire 49 stretched between posts 50 provided in the top portion of 12. The hook 48 is soldered to the wire 49 and serves as the lower pivot of the transmitter.

The electrodes 30 and 32 are separated from the edges of the circle formed by 41 and 42 by means of felt rings 51 and 52. The two chambers enclosed by the three electrodes and strips 41 and 42, are entirely filled with finely granulated carbon or other suitable comminuted conducting material.

When the device is in operation, the vertically or laterally grooved phonograph record vibrates the stylus and the latter causes the rocking of reproducer 12 on the knife edge pivots 16 and 17. The vibrations of 12 are dampened by cushions 21 and 22, and through the agency of wire 49, hook 48 and arm 47, these vibrations are transmitted to the transmitter. The electrodes 30 and 32 bein held stationary, only the electrode 31 an the holding strips 41 and 42 respond to the vibrations of 12. These elements forming a unit pivoted at its two ends, readily respond to the vibrations of 12 and vibrate to compress or permit the' diffusion of the carbon granules in the chambers on the two sides of electrode 31. This determines the resistance variations in the transmission circuit.

This arrangement is particularly adapted to prevent the distortion of sound vibratlons that may result from lack of synchronism between the o erations of the telephonic and reproducing e ements. The three electrodes are continuously in contact with the carbon granules preventing thereby any interruption in the electrical transmission circuit. Due to the fact that the chambers are entirel filled with carbon granules, and that a re atively large mass (41, 42, 31 and the carbon granules) is freely vibrated, the danger of the electrode 31 ioperating out of synchronism with: the carbon granules is reduced to a minimum. Furthermore, the.

carbon granules are readily responsive to is vibrated and not an electrode in front of a stationary chamber. The carbon granules are continuously subjected to effective shaking whereby their packing is prevented.

The electrical circuit through which the musical sounds are transmitted is illustrated in Fig. 8. 60, 61 and 62 are conductors leading to the three electrodes. By means of a switch 63, 64, 65 of any suitable design, these conductors ma be connected with a receiving set comprising a battery 66, an induction coil 67 and a tele hone receiver 68. The primary winding 0 the induction coil is divided into two sections, a and b, and the current source is connected midway between these two sections. The secondary winding 0 of the induction coil is connected with the receiver.

' In assembling the device, first the stri s 41 and 42 are fastened together with t e electrode 31 clamped in place. This assembly is mounted on the support 6 and the hook 48 is soldered to the wire 49. Then one chamber is filled with granular carbon, the felt washer 51 put in place and the electrode 3O laid thereon. The bridge 35 is now screwed down and the electrode 30 fixed in its properly adjusted osition b means of screw 38. Then the other cham er is filled and the electrode 32 adjusted. The stationary electrodes are always easily accessible for correcting their adjustment.

What I claim is:

1. An electrical transmitter device, comprising a movable electrode providing upon its opposite sides chambers for holding comminuted conducting material, and stationary electrodes upon either side thereof to retain therein the comminuted material.

2. An electrical transmitter device, comprising two separate and clamping members and a conducting wall held thereby, said members providing chambers upon opposite sides of the wall for holding comminuted conducting material and constituting with the wall a movable electrode, and stationary electrodes upon either side thereof to close the chambers and retain therein the comminuted material.

3. An electrical transmitter device, comprising two movably mounted strips of relatively light material and secured together, a diaphragm held thereby to provide two chambers for holding comminuted conducting material, and stationary electrodes upon either side thereof to retain therein the comminuted material.

4. An electrical transmitter device, comprising two movable strips of light material secured together and having a longitudinal rib along the median plane of each strip and a corresponding groove along the inner surface, and a diaphragm held in the said groove, the same constituting a movable tionary electrodes upon either side thereof.

5. An electrical transmitter device, comprising a movable electrode providing 6 upon its opposite sides chambers forholding commmuted conducting material, stationary electrodes upon either side thereof to retain therein the comminuted material and a stylus adapted to communicate movement to the movable electrode.

6. In an electrical transmitter device, two strips of relatively light material held together at their ends, a. rib along the outside surface and a corresponding groove along the inside surface of each strip, an electrode held in'thegrooves of the strips intermediate the ends thereof, a carbon granule chamber on each side of said electrode, the walls of said chambers being constituted by said electrode and strips, a support, two electrodes fixed thereto, each constituting the enclosing wall of one of said chambers, and a pivotal suspension for one end of said strips on said support.

7. In an electrical transmitter device, two strips of relatively light material held together at their ends, a rib along the outside surface and a corresponding groove along the inside surface of each strip, an electrode held in the grooves of the strips intermediate the ends thereof, a carbon granule chamher on each side of said electrode, the'walls of said chambers being constituted by said electrode and strips, a support, two electrodes fixed thereto, each constituting the enclosing wall of one of said chambers, a pivotal suspension for one end of said strips on said support, a reproducer, and a stylus therefor connected with said strips.

8. In a reproducin and transmitting device, two strips of re atively light material held together at their ends, a rib along the outside surface and a corresponding groove along the inside surface of each strip, an electrode held in the grooves of the strips intermediate the ends thereof, a carbon granule chamber on each side of said electrode, the walls of said chambers beingconstituted by said electrode and strips, a support, two electrodes fixed thereto, each constituting the enclosing wall of one of said chambers, a pivotal suspension for one end of said strips on said support, a reproducer, a stylus therefor, a plate fastened to said support, strips of cushioning material thereon seating said reproducer, a mechanical connection between said reproducer and the other end of said strips, knife-edge pivots for said reproducer on said support, and electrical connections to said electrodes.

In witness whereof I have hereunto set my handthis 17th day of February, 1921.

ARTHUR P. PINKLER.

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