US1813483A - Automatic brake for talking machines - Google Patents

Description

July 7, 1931. 5. F. CLARK 1,813,483

AUTOMATIC BRAKE FOR TALKING MACHINES Filed May 10, 1930 3 Sheets-Sheet l July 7, 1931. G. F. CLARK 1,813,483

AUTOMATIC BRAKE FOR TALKING MACHINES Filed May 10, 1930 3 Sheets-Sheet 2 July 7, 1931. G. F. CLARK AUTOMATIC BRAKE FOR TALKING MACHINES Filed May 10, 1950 5 Sheets-Shee 3 20 2 s4 35 Fi .4.

7 TORNEYS.

Patented July 7, 1931 UNITED STATES PATENT, OFFICE GEORGE FnEnEnICKcLAn-K, OF WEST DRAXTON, ENGLAND, ASSIGNQR To VICTOR TALKING 'MACHINE COMPANY, A CORPORATION on New JERSEY AUTOMATIC BRAKE FOR TALKING MACHINES Application filed. May 10, 1930, Serial NO. 451,429, and in Great! Britain .Tune

This invention relates to improvements in automatic stopping devices for talking machines and in particular to stopping devices for talking machines in which the turntable is driven by an electric motor.

Devices have been used in the past which were movable by hand or automatically to bring a member into or out of frictional engagement with a rotatable part of the machine and at the same time open or close an electric switch in the motor circuit to stop or start the machine.

According to the present invention stopping mechanism for an electrically driven talkmg machine is provided comprising a member adapted to bring the rotating parts of the machine to a standstill by friction and mechanism operable through said frictional member and by the momentum of the rotating parts to open a switch in the electric circuit ofthe driving motor.

The invention is illustrated by way of example in the accompanying drawings, the

- parts of the talking machine-unnecessary to lines the parts moved partly towards the re- 40 starting positions.

Fig. 4 is a view of the mechanism in side elevation looking from the right in Fig. 1.

The automatic stopping device illustrated is of the kind which is operable to stop the talking machine when the direction of movement of the sound arm is reversed, by the engagement of the stylus in an excentric groove provided at the centre of the record.

Referring to the drawings, the stopping mechanism is mounted on a base plate 1 fixed to the motor board ofthe machine in a position beneath the turntable 2, part only of which is shown. stopping device comprises a lever 3 pivoted at 1 on the base plate, and engagingin well known manner with a pin 5 extending downwardly from the sound arm 6 so that said lever 3 moves in conjunction with the sound arm. A second lever 7 is mounted to move about the pivot 1 and this lever 7 is heldin frictional engagement with thelever 3', so that it tends to movetherewith about pivot 4. The lever 7 is providedwith a forked end 8 and the fork engages a pin'9 on a pivoted stop lever 10 mounted to move about a pivot 11 to a limited extent as permitted by a pair of stops 12, 13, and the stop lever 10 is moved against one or other of the stops 12 01313 according to the direction in which the sound arm and therefore levers 3 and 7 are moved. The central boss 14 beneath the turntable 2 is surrounded by a sleeve 15 and with the inner surface of this sleeve 15 engage a num ber of fibre friction pads 16 carried in apertures in the walls of the boss 14 and urged outwardly by a spring ring 17. The outer surface of thesleeve' 15 is furnished with a number of radial projections 18. j

During playing of the machine the sleeve 15 rotates with the turntable 2 and as the sound arm 6 swings in over the record; the lever 3 is moved in a counterclockwise direction, and stop lever 10 isheld firmly up against stop 12 through the frictional engagement between levers 3 and 7. Under these conditions the end 19 of stop lever 10 occupies the position shown in Fig. 1 where it is out of the path of the projections 18 on sleeve 15'.

When however the end of the record is reached, the direction of movement of the sound arm 6 is reversed 111 well known'manner, throughthe engagement of thestylus in an excentric groove provided at the centre of the record. In consequence levers 3 and 7 are moved clockwise and stop lever 10 moves about its pivot and against stop 18 and the end 19 ofthe lever lO moves into the path of one or other of the radial projections 18 on sleeve 15 and the latter is brought to a standstill. The rotation of the turntable there'- The automatic frictional upon ceases by virtue of the frictional engagement between the fibre pads 16 in the apertures in the turntable boss 14.- and the inner surface of sleeve 15.

In accordance with the present invention an arrangement is provided whereby the thrust imparted to the stop lever 10 by the momentum of the turntable when the end 19 of the lever 10 is engaged by a projection of sleeve 15, is utilized to open an electric switch in the electric circuit of the driving motor.

For this purpose there is mounted on the motor board of the machine a switch 20 comprising a pair of horizontal plates 21 of insulating material between which are mounted a pair of spring contacts 22, 23 one of which 22 biased in such a manner as to tend to move away from the other.

Pivotally mounted at 2% on the base plate is a member 25 in the form of a metal plate to which is fastened a block 26 of insulating material. The block of insulating material 26 engages the spring contact 22 of the switch and the tendency is for member 25 to be moved in a counterclockwise direction about its pivot 2 1 by the spring contact 22. The edge of the member 25 away from the block 26 is formed with two arcuate recesses 27, 28 with a projection 30 between them.

The stop lever 10 of the stop mechanism described above is pivotally mounted on a plate 29 which is itself mounted for limited pivotal movements about a pivot 31 on the base plate 1 and the stops 12, 13 are also formed on the plate 29. A stop 32 is provided on the base plate 1 to limit the extent of movement permitted to plate 29 in one direction about pivot 31. On the end of plate 29 is provided a roller 33 which engages in one or other of the recesses 27, 28.

The operation of opening the switch when the end of a record is reached takes place as follows:

The direction of movement of the sound arm having been reversed and the end 19 of stop lever 10 having been engaged by a radial projection 18 as described above, the parts are momentarily in the position shown in Fig. 2.

The tendency of the turntable to continue its rotation under its momentum results in a longitudinal thrust being imparted to stop lever 10. As a consequence plate 29 is moved about its pivot 31 on the base plate 1 in a counterclockwise direction until its edge engages stop 32. During this movement roller 33 first moves from recess 27 moving member 25 slightly clockwise until the roller passes the projection 30 whereupon member 25 snaps 8 at the end of lever 7 is of sufficient length to permit the necessary movement of pin 9 on lever 10.

Means are provided to permit the end 19 of I lever 10 to be moved from engagement with projection 18 and the switch contacts 22, 23 to be closed by a manual movement of the sound arm 6 outwards to re-commenee playing.

The stop lever 10 is provided at the end away from end 19 with an extension 34 the edge of which forms a cam surface and cooperates with a roller or stud 35 on the free end of lever 3.

As the sound arm 6 is swung outwards the lever 3 is moved clockwise about its pivot 4 and the roller or stud 35 engages the cam surface on extension 34 of lever 10. As a first result lever 10 is moved about its pivot 11 until said lever engages stop 12 on plate 29 and the end 19 is moved from the path of the extension 18 on sleeve 15. Continued movement of the sound arm in the same direction results in members 10 and 29 moving as a unit about pivot 31 until roller 33 is re-engaged recess 27 and the switch contacts closed.

I claim:

1. Stopping mechanism for an electrically driven talking machine comprising a member adapted to bring the rotating parts to a standstill by friction and mechanism operable through said frictional member and by the momentum of the rotating parts to open a switch in the electric circuit of the driving motor.

2. Stopping mechanism for an electrically driven talking machine comprising a stop member in frictional engagement with the rotating turntable or other rotating part of the machine and normally rotating therewith, a pivoted member movable about its pivot to bring a part of said member into engagement with the stop member, said pivated member being itself mounted on a movable member which is moved, when a thrust is imparted by the stop member to the pivoted member under the momentum of the rotating turntable to open an electric switch in the motor circuit.

In testimony whereof I have signed my name to this specification.

GEORGE FREDERICK CLARK.

back under the urge of spring contact 22 j with roller 33 engaged in recess 28, and the switch contacts 22 and 23 are now parted and the electric motor circuit open. all the parts being in the position shown in full lines I in Fig. 3. It will be observed that the fork

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