US2295712A - Recorder-reproducer head - Google Patents

Description

SePt- 15, 1942- w. `J. BRowN 2,295,712 vRECORDER-RE].:`RODUCER HEAD Filed oct. 7, 1941 @L4M J :ur'lomonmx /N VEN TOR WJ BROWN @www invention;

Patented Sept. 15, 1942 RECORDER-REPRODUCER HEAD William J. Brown, West Englewood, N. J., assignor to Western Electric Company, Incorporated, a corporation oi' New York Applicationl October 7, 1941, Serial No. 413,932

5 Claims. (Cl. 274-30) This invention relates to phonograph recording and particularly to combination machines for both recording and reproducing purposes.

The object of the invention is a compact unil tary recorder-reproducer head which is capable of reproducing the recorded material practically l simultaneously with the recording operation.

In prior machines of this type, the recorder and reproducer are mounted separately to engage the record either on opposite sides of the spindle or at least some distance apart along the same groove. Due to space limitations in- .herent in these designs, there is necessarily considerable time lag in the reproduction of matter being recorded and the use of separate mount ings makes the necessary supporting superstructure complicated and expensive. I Y

In the combination recorder-reproducer head .of this invention, the recorder is mounted directly above the reproducer with its stylus projecting through an aperture in the reproducer structure between the reproducer stylus and its vassociated translating unit. 'I'he reproducer stylus tracks the groove only aifraction of van inch behind the recorder stylus and therefore reproduces the recorded matter only a small fraction of a. second after it is recorded.

In the preferred structure the two devices are I mounted on separate horizontal pivots within a common housing so that either one alone or .both may be in engagement with the record surface. The recorder is xed in a lateral sense so that it may be positively driven by the usual lead screw but the reproducer is capable of limited motion about a vertical pivot so that it may track as much as several grooves behind* the recorder stylus position if d sired.

In the drawing:v t

Figs. l and 2 are t'op and side views respectively of the reproducer head vaccording tothe Fig. 3 is a sectional view showing the reproducer and its mounting; and

Fig. 4 is a partial section showing the reproducer lifting mechanism.

The recorder I is mounted within the casing 2 by means of a mounting bracket 3 secured to the recorder structure by screws 4, 4 and hav'- ing downwardly depending lugs 5, 6 which are engaged by the set screws l, 8 in the casing to form a pivot axis about which the recorder may be rotated into and out of `engagement. with a extending arm 9 terminating in a sloping surface Iii engaging a rollerII on the cam fixed to the shaft I3. The shaft projects through a bearing I4 in the casing and mounts a recorder lever I5 which, Awhen depressed from the position in which it is shown, rotates the cam I2 k and permits the recorder to pivot about its axis through the screws 1, 3 until its stylus I6 is in contact with the record.

The reproducer II h as a mounting bracket I3 with backwardly extending lugs I3, secured by screws 2|, 22 to the cross member -23 which is center pivoted on the casing 2 lby the screw 24. The lug 23 extends beyond the member 23 and engages the grooved' roller 25 on the cam 26 which is secured on the shaft 2l and operated by the reproducer lever 23. When this lever is depressed the reproducer moves downwardly about the axisformed by the screws 2l, 22 toA rbring the reproducer stylus 29 into contact with lrecording surface. The lug 5 has a backwardly l the record groove.

By means of the member 30 secured to the reproducer and projecting through the front of stylus either in thegtoove being cut or in an adjacent groove. When a record previously made is being played back, the reproducer may be set to engage a groove on either side of its normal position without shifting the casing with respect to the lead screw. This is particularly convenient when itis desired t0 repeat a small portion of a reproduction.

The aperture 33 in the reproducer through which the recorder stylus projects must be large enough to permit the desired excursion of the reproducer from its normal position. In cases where immediate reproduction is important, it should also be as close to the reproducing vstylus as possible. In the structure shown, the'spacing between the stylus is of the order of only one quarter inch so that for any practical recording speed the reproduction is substantially instantaneous.

The reproducing stylus 29 is operativly connected to the translating unit by means of a stiff wire 34 offset at the aperture 33 to by-pass the recorder stylus as shown in Fig. 3. `The recorder A and reproducer shown are both of the weil-known piezoelectric type for lateral cut records. While translating devices of any other known types may be used, the crystal reproducer is particularly suitable since its vertical dimension may be very small thereby reducing the necessary length and stiffness requirements ci the Arecorder stylus to a I2 which is 55 minimum.

The casing 2 has clamping screws 35, 36 in an end block l1 vwhich is shaped for a sliding fit in a supporting arm on thecarriage or the machine with which the assembly is to be used. Electrical connections (not shown) are provided from the recorder terminals 38, 38' and the reproducer terminals 39, 39 to the plug terminals 40, Ill, 42 in the end block 31 so that both translating devices are connected to the amplifying system automatically when the assembly is-secured to the machine.

While the invention has been described with Y aperture in the reproducer.

2. A recorder-reproducer assembly for phonographs comprising a recorder having a stylus for forming a groove in a record member, a reproducer having a stylus and a body portion with an aperture near the stylus, a casing, means for mounting the reproducer within the casing for movement about vertical and horizontal pivot graphs comprising a recorder having a stylus for forming a groove in arecord member, a reproducer having a stylus and a body portion with an aperture near the stylus, a casing, means for supporting the recorder and kreproducer within the casing with the recorder stylus extending downwardly through the aperture in the reproducer, and means externally of the casing for independently adjusting the recorder and reproducer with respect to the record.

4. A recorder-reproducer assembly for phonographs comprising a recorder having a stylus 'for forming a groove in a.- record member, a reproducer having a stylus and a body portion with an aperture near the stylus, a casing, means for y mounting the reproducer within the casing for ases, and bearings for supporting the recorder in the casing above the reproducer with the re- 'corder stylus extending downwardly through the aperture in the reproducer.

movement about vertical and horizontal pivot axes, a horizontal pivot axis supporting the recorder in the casing above the reproducer with the recorder stylus extending downwardly through the aperture in the reproducer and means exsecured to the shaft externally of the casing.

WILLIAM J. BROWN.

3. A recorder-reproducer assembly for phono-

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