US2012326A - Automatic talking machine - Google Patents

Description

Aug 7, W35. H. A. THOMPSETT 2,012,326

AUTOMATIC TALKING MACHINE Filed Dec. 4, 1930 lrzven for:

HarryflrChib hornpsetl 5 y 2102" y.

Patented Aug. 27, 1935 PATENT OFFICE AUTOMATIC TALKING MACHINE Harry T Archibald Thompsett, London, *England,.- 1 p asslgnor, by mesne assignments, toRadio- Corporation of America, New York, N. Y., a corpof ration of Delaware I Application December 4, 1930,. Serial No. 499,999 In Great Britain December 16, 1929 7 Claims. ,lGl. 179100.4) 1,.

This invention relates to improvements in auto--' matic talking machines andin particular to automatic talking machines of the kind Operating with an electrical reproducer or pick-up. With machines of this kind, there are periods of time between the completion of one reproduction and the commencement of the next when the needle of the reproducer is in engagement with a part of the surface of the rotating record in the playing position which does not contain the sound record groove. For example, at the end of the automatically effected repositioning movement of the reproducer, the needle may be engaged with the part of the surface of the record outside the commencing groove preparatory to being fed 'in- Wardly to commence reproductionof a selection. With machines of this kind, as hitherto known, the engagement of the needle or stylus of an electrical reproducer with parts of the moving record outside the sound record groove gives rise to unpleasant noises which are due to movements imparted to the stylus as it slides over the record surface, these movements being converted into electrical oscillations which are amplified and transmitted to the loudspeaker.

Furthermore, there is the possibility'of other noises being produced in the loudspeaker during the carrying out of automatic operations apart from those referred to above, due to the engagement of the stylus with the record surface.

The object of the present invention is to provide a machine in which the occurrence of these unpleasant noises is avoided.

According to the invention, meansare provided whereby the electrical circuit of the electrical reproducer or pick-up is short circuited as soon as a series ofautomatic operations is commenced, the short circuited condition being'maintained until the needle is in engagement with the commencing sound line of the record to be" played. Instead of the pick-up leads being short circuited, the object of the invention maybe achieved 'by short circuiting the amplifier or even the loudspeaker itself. The invention is readily applicable to a machine of the kind described in my Patent No. 1,879,593 in which the motor of the machine is coupled at intervals to a cam shaft through which all the automatic operations of the machine, including the ejection of the played record, the feeding of a new record to the playing position and the repositioning of the reproducer, are eifected. The invention is also applicable to other types of automatic machine such as those which are adapted to repeatedly play a single record.

The invention is illustrated, by way of example, in the accompanying drawing as applied to an automatic talking machine of the kind adapted to play a series of records fed singly or in succession to the turntable from a magazine as described in my above referred to patent and using an electrical pick-up. T J

Fig. '1 illustrates the short circuiting device according to the invention in plan View.

Fig. 2 is a view in elevation corresponding to Fig.1.

Fig. Sis the circuit diagram.

In themachine according to my above-identified patent', a cycle of automatic operations including the raising, swinging andlowering of the sound arm, feeding of records from the magazine tothe turntable and ejection of played records are effected during one complete revolution of a cam shaft which is held stationary during playing of a record but is coupled to the machine motor, so as to be rotated thereby to make one complete revolution, by' a clutch device operable by a reversal of the direction of movement of the sound arm when the stylus reaches the end of a record.

In the drawing, l represents the cam shaft carrying a gear wheel 2, Fig. 2 ,through which it is rotated at intervals by the machine motor, not

shown.

The cam shaft l is mounted for rotation in a bearing sleeve .3 carried'on a base plate 4, and beneath this base. plate 4, in a suitable position, is carried a bracket 5. The bracket 5 serves to support an electric switch formed by two spring blades 5, 'l insulated from one another and from the base plate 4 by blocks 8 of insulating material. The blades 6 and Tare connected electrically, one to each of the leads connecting the pick-up, represented diagrammatically .by 9 in Fig. 3, to the amplifier l0. I

The blades 6, 1 are provided on adjacent faces and near their free ends with suitable contact points ll, l2 and the arrangement is such that the blades 6, I tend to contact with one another to bring the points H, I 2 together to thereby short'circuit. the pickup. The free end of the blade 6 is provided with a curved extension I 3.

On one of the. cams l4 fast on shaft I is fixed a button I 5 of insulating material, and the position of this button IS on cam M is such that, during playing of a record, the button 15 is held stationary in the position shown in Fig. 1 where it engages the extension l3 of blade 6, so that the latter is deflected and the switch is held open.

As soon as rotation of the cam shaft I commences in the direction indicated by the arrow in Fig. 1 to effect the automatic cycle of moveis now broken in known manner so that the cam I4 is brought to a standstill in a position where the switch 6, 7 is open.

The position of the insulated button lii on the cam M and the timing of the movements of the cam shaft l and the reproducer moving means, not shown, may be so selected and determined that the stylus of, the reproducer or pickup 9 contacts with the record tobe played and moves into engagement with the first sound record groove before the short circuiting switch 6, l' is opened, 'so that the amplifier and loudspeaker remain uninfiuenced by the pick-up until the required moment.

' I claim':

1. The method of controlling an automatic phonograph of the type including an electrical reproducing 'instrumentality in circuit with an audio amplifier and adapted to successively reproduce a plurality of records-in cycle by means of said instrumentality which comprises shortcircuiting said instrumentality during at least a portion of the non-playing part of the cycle whereby to prevent any. output signals from said instrumentality from reaching said amplifier during said'portion.

2. The method of controlling an automatic phonograph of the type adapted to successively reproduce a plurality of records electrically by means of an electrical 'reproducer in circuit with an audio' amplifier and to performa cycle of automatic operations between succeeding records which comprises short circuiting' the electrical reproducer thereof as soon as the cycle of operations is commencedupon completion of each individual record to prevent any reproducer output signals from reaching said amplifier, and maintaining said reproducer in short-circuited condition until the reproducer is in engagement with the sound track of the succeeding record.

3. In a phonograph of the type wherein sound is reproducedfroma record having a recorded portion and an unrecorded portion, the combination of an electrical translating device'adapted to be energized by either of said portions, an

audio amplifier in circuit with 'said device, switch means connected across said 'device'in advance of said amplifier forcontrolling the operating condition of said device, and means for maintaining said switch means closed, whereby to 4. In an automatic phonograph of the type adapted to carry out a cycle of automatic operations and wherein sound is reproduced from records having a recorded portion and an unrecorded portion, the combination of an electrical sound reproducing device adapted to be energized by either of said record portions, an audio amplifier in circuit withsaid device, a switch connected across the output of said device in advance of said amplifier for controlling the operating condition thereof, means for maintaining said switch open while said device is in engagementwith the recorded portion of a record, whereby to render said device operative to reproduce sound, and means whereby said switch is maintained closedafter said device is in engage- 'ment with the unrecorded portion of the record and for the balance of the cycle, whereby to render said device inoperative to reproduce sound.

5. In an automatic phonograph of the type adapted to carry out a cycle of automatic operations and wherein sound is reproduced from records having a recorded portion and an unrecorded portion including acontrol groove at the end of the sound groove for controlling the operating cycle of the phonograph, the combination of an electrical sound reproducing device adapted to be energized by either of said record portions, an audio amplifier in circuit with said device, a switch connected across the output of said devicein advance of said amplifier for controlling the operating condition thereof, means for maintaining said switch open while said device is in engagement with the recorded portion of a record, whereby to render said device operative to reproduce sound, and means whereby said switch is maintained closed during the balance of the cycle after said device has engaged said control groove and a series 'of'automatic operations has been initiated, whereby to render said device inoperative to reproduce sound during said balance of the cycle.

6. In a phonograph, an electrical translating device, a switch connected across the output of said device, said switch including a pair of spring members constantly tending to contact each other, said spring members causing said device to be short circuited when in contact with each other, a rotatable shaft, means fixed to and rotatable with said shaft, and a switch engaging member on said means adapted to be moved into engagement with one of said spring members as said shaft rotates whereby to maintain said spring members separated.

device, a switch connected across the output of said device and adapted, when closed, to shortcircuit said device, a rotatable shaft, a member fixed to and rotatable with said shaft, said member including a switch controlling element, and

said switch including a pair of spring blades one of which is located in the'path of movement of said element, whereby said element is adapted to engage one of said spring blades in response to rotation of said shaft.

' 1 HARRY ARCHIBALD THOMPSETT.

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