US2078928A - Stylus arm switch - Google Patents

Description

` May 4, 1937.

L.. J. ANDRES 2,078,928

STYLUS ARM SWITCH Filed Dec. 28, 1954 3 Sheets-Sheet l INVENTORL 150%/ 'Ji/ms ATTORNEY.

A' May 4, 1937. L. J. ANDRES l2,078,928

STYLUS ARM swITcH i Filed nec. 28. 1934 s sneets-sheet '2 -m-llllmlllllnh. 33

mmm y l INVENTOR.

BY, ATTORNEY.

May 4, 1937. L. 4. ANDRES 2,078,928

STYLUS ARM SWITCH l Filed De. 28, 1954 V55 Sheets-Sheet 3 mmm INVENTOR.

ATTORNEY.

Patented May 4, 1937 STYLUS ARM SWITCH Lloyd J. Andres, Grand Rapids, Mich., assignor to Automatic Musical Instrument Company, Grand Rapids, Mich.,l a corporation of Michigall Application December 28, 1934, Serial No. 759,529

9 Claims. (Cl. 192-119) This invention relates to improvements in the stylus arm switch operating mechanism of phonographs, and objects of the'invention are to provide a simple and reliable means for operating the switch, or other trip mechanism which starts the restoring operations at the completion of the playing of a record; to provide a trip mechanism which is readily adjustable, and will operate -the switch whenrecords having either aconcentric terminal groove or an eccentric terminal groove are being played.

In the concentric style of record terminal grooving the arm is moved to its full inward position by a spiral groove portion vwhich leads in from the end of the record groove to a small standard size concentric groove; and in the other type, the recording terminates in an eccentric groove which may be of diiierent sizes and does not in all cases approach close enough to the center of the center of the record to swing the arm far enough in to operate the switch.

As is well known in automatic phonographs, a stylus arm` switch is commonly provided which is operated by the arm in completing the playing raising and swinging the arm back away from the turntable, to restore the machine to normal conditions, to replay the record, or for other purposes whichvmay be provided for in the machine. Also in place of an electric switch, a mechanical trip mechanism may be used. It will become I apparent that the device of this invention is suitable for operating either the electric switch or the mechanical trip providing they can be operated by contacting means, as is usually the case. Thus it is apparent that this invention contemplates, providing means which may be used ln connections with either an electric or mechanical trip mechanism, the word switch being used to include both, as a matter of convenience.

In this invention the one and same switch contacting member is operated always bythe forward movement of the arm, whether this movement is continuous or intermittent. This eliminates the necessity of providing two parts or reverse movement levers. Also there is no lifting pressure or undue frictional resistance exerted by the stylus arm.

Preferred embodiments of this invention are which;

Fig. 1 is a plan view-of a well-known phonov graph mechanism in which my invention is incorporated, partsbeing omitted, or broken away,

and parts being shown in broken lines;

of a record to set into operation mechanism for.

illustrated in the accompanying drawings, in'

Fig. 2 is a. rear side elevation of Fig. 1 with the parts in normal inoperative position;

Fig. 3 is a detail view of the stylus arm switch 4operating mechanism in normal condition and is groove being shown in Fig. 1;

Fig. 'l is a view taken similar to Fig. 5, but showing a modified construction; and

Fig. 8 is a representation of an eccentric terminal groove record.

The phonograph mechanism shown has a base frame I on which is mounted the operating parts comprising a turntable 8, rotated by a motor 9. A stylus arm l0, having a needle II, is horizontally and vertically pvoted on a post I2, rising from the base frame at one side of the turntable. The base portion I3 of the arm is pivotally connected by trunnion screws I4 to a sleevev I5 which is rotatably supported on a vertical shaft IG, iixedly mounted in and projecting from the upper end of the post I2. A bracket arm I'I extends forwardly from the base portion I3, which rests on the periphery of a attened flange.

'Ihe stylus arm functions in the usual manner. In normal inoperative conditions, the arm is at one side ofthe turntable and raised-as shown in Fig. '2 and shown partially outlined by broken lines in the upper portion of Fig. 1. record I8 is on the table, the arm is swung over the outer 'edge of the record and is lowered to place the needle in the beginning of the record groove. The arm being slightly overbalanced rests lightly inthe groove and is freed so that the end of the arm is carried inward, by the needle in tracing the groove as the record is played, to the iinished playing position near the Whena center of the record. This position of the ar m is indicatedin broken lines in Fig. 1.

"stylus arm switch 4|.

from the center of the record and the circle 23 being sufficiently small that the switch is contracted during the movement of the arm in the lead-in spiral.

In the particular phonograph mechanism shown, the stylus arm is controlled by a bracket arm 24 which extends forwardly from the base portion I3 underneath the stylus arm and nor- `mally rests on a ange 25 formed on the end of a cam drum 26. It is to be understood that the cam drum is rst rotated clockwise, as viewed in Fig. 2, nearly one complete revolution by a -transfer motor 21, to swing over and lower the arm-to start the playing; and at the end of the playing the drum is rotated counter-clockwise back to normal position to pick up and swing the stylus arm back from over the record.

To effect these movements, the bracket 24 is provided with a depending pin 28 which enters a spiralling groove 29, formed in the periphery of the drum, and the flange is iiattened at 30 to lower the arm at the proper time.

A horizontally disposed, sheet metal supporting member 3| is iixedly mounted on a post 32, formed on the base 1 a short distance from the post I2; and on the forward end of the bracket is fixedly secured a depending plate 33 which overhangs the support member 3|.

A spaced pair of lugs 34 project from the plate 33 and engage in triangular apertures 35 which are formed in a switch contracting slide plate member 36. Thus the plate 36 is loosely supported on the bracket plate 33, and it is lifted out of contact with thev surface of the horizontal member 3|, when the arm is in normal and raised position, as shown in Fig. 3. In this position, the lugs are engaged in the upper corners of the apertures, and the plate is thereby positioned relatively to the right on the stylus arm, which is the retracted and normal position of the plate.

A gravity operated ratchet pawl 35a is pivotally mounted on the plate 33 and it is limited in rotation by stop pins 31 and 31a, mounted in the plate 33. The upper edge of the operating member 36 is recessed to accommodate the pawl 35a and is provided with rearwardly facing ratchet teeth 38 which are normally spaced below and out of co-operative relation with the pawl 35a, as shown in Fig. 3.

'I'heforward or left end of the plate 36 is bent laterally to receive an adjustable contact screw 40 which contacts and closes the spring-finger The switch=4l is mounted on the member 3| and positioned in the path of the screw 4l so that it is contracted thereby when the stylus arm is swung into its full inward position as in playing the record 2l.

When a stylus arm is lowered onto the record, the plate 36 then rests on the surface of the member 3|, and is held up so the lugs move down to the lower portions of the apertures. Also the pawl 35a moves down into contact with the ratchet teeth 33. These parts remain in this relation as the plate 36 is carried over to contact with the switch 4|, as shown in Fig. 4, when a concentric terminal groove record is played which carries the stylus fully inward.

When a stylus arm movement stops before reaching the inner position, and the arm is then reciprocated by an eccentric terminal groove I3, the hanging plate 33 is held from backward movement by the frictional contact with the surface of the member 3| while the pawl is moving backward over the ratchet teeth 38. 0n each succeeding forward movement of the stylus arm the plate is fed forwardly and advanced with respect to the arm by the pawl until the screw contacts the switch. This, as will be understood, starts the motor 21 into operation to turn the cam drum reversely and eifect the lifting and restoring of the stylus arm to normal position. It will be noted that when the stylus is raised, the lugs engage the angular upper sides of the apertures, and the switch operating plate slides back into the normal retracted position, and is thereby restored to normal position.

This switch operating mechanism, while it functions in different ways, is extremely simple, and is entirely automatic in its operation. The switch operating member is always advanced by the forward movements of the arm, whether it is carried directly in, or the arm stops and reciprocates. Thus movement reversing parts are eliminated, and the one member serves to operate the switch when either kind of records are used.

'I'he tripping contact plate member described "i above, is obviously restored by gravity. The plate member drops down on the lugs 34 as the arm is raised. The lugs slide along the inclined edges of the slots 35. This moves the plates rearwardly or to the right, as viewedv in Fig. 3 and on, and

the member is lifted free of the platform plate 3| when the stylus arm is in its upper position, in which position the pawl 35a is freed from the ratchet teeth 33.

When a more positive control is desired I add extended between the projection 43 and outer end of the projection 42 to urge the slide plate 36 rearwardly to restore it to normal position. 'Ihen ratchet teeth 44 are provided in the lower edge of the slide 36, and the pawl 42 pivotally mounted on the lower side of the platform 3|. The pawl is counterweighted to rotate clockwise, as viewed in Fig. '1, so that the end projects into engaging relation with the teeth 44, when the arm is down.

Having thus described my invention, I claim:

1. In a phonograph having a turntable and a swingable stylus ann having a needle for tracing the grooves of records placed on the turntable, a slide loosely mounted on the arm, a switch flxedly mounted in the path of the slide, and ratcheting means for advancing the slide on the arm in the step by step forward movement when the arm is reciprocated by records having eccentric terminal grooves so that the slide will be moved continuously forwardly to contact with the switch by the forward portions of the reciprocating movements of the arm.

2. A phonograph having a turntable for supporting grooved disc records, a stylus arm having a needle for tracing the grooves of the records, the

arm being pivotally mounted adjacent the turnina step by step mannerby the'inward reciproeating movements of the arm'until the arm contacts with the switch: l 3.`A phonograph having a .turntable for sup-` porting grooved disc records, a stylus arm having a needle for tracing the grooves -to play the record,

the arm being mounted'adjacent so that it may be swung overA and lowered to engage the needle in the groove and raised and back from l the turntable at the completion ofthe playing, a

2 0 movements of thearm in a step by step manner in playing an eccentric terminal groove record to eventually contact the trip.

4. The combination with a phonograph stylus arm, of a switch mounted in co-operative relation with the arm, a plate loosely mounted on the arm, and ratcheting means for advancing the plate to contact with the switch when the arm is being reciprocated by eccentric groove terminal records, theA plate being advanced in one direction by suc- '0 cessive inward movements of the arm.

5. The combination with a phonograph stylus arm, a switch mounted in co-operative relation with the arm, a self-restoring switch operating pla'te hung loosely on the arm -to contact the switch when the arm is swung fully inward in playing a concentric terminal groove record, the plate having a row of ratchet teeth, a ratchet gdog mounted on the arm,and a frame plate for supporting the switch-plate Inco-operative relation 40 with the ratchet dog when the arm is lowered so that the switch plate will be advanced to. contact the switch when the arm is reciprocated by records'having eccentric terminal grooves.

6. In combination with a phonograph tone 4.-'. arm, having lugs, a self-restoring contact plate in angularly slotted engagementen the lugs, a supporting surface member ilxedly mounted beaovaeas 3 low the arm, and a ratchet pawl mounted on the arm above the plate, the plate having teethin its upper edge for ratcheting engagement by the pawl .for advancing the plate when the arm is lowered andthe plate is resting on the supporting surface, and the plate being dropped down away from the pawl Iand restored to starting position when the arm is raised.

7. In combination with a phonograph tone arm, an apertured self-restoring switch contact plate, a depending bracket mounted on the arm and having lugs for engaging in th'e apertures of the plate, a pawl for advancing the plate mounted on'the bracket and spaced above the plate when the arm is raised, a horizontal member disposed Anormal position when the arm `is raised and the plate is lifted from the supporting surface.

8. In a phonograph, a vertically and horizontally movable tone arm, a depending bracket carried by the arm'and having posts. a plate loosely hung on the posts by means of -apertures in the plate having angular surfaces for retracing the plate when the arm is. raised and the plate is freely hanging on the posts, a ratchet pawl mounted on the bracket above the plate, and a supporting member disposed underneath the arm for supporting the plate in co-operative contact withthe pawl when the arm is lowered into position for playing a record.

9. In a phonograph, a vertically and horizontally movable tone arm, a switch mounted in cooperative relation with the arm, a plate loosely mounted on the arm, rateheting means for successively advancing the plate in a step by step movement in one direction to contact with the switch when the arm is reciprocated by eccentric groove terminal records, and means for releasing the ratcheting means'and returning the plate to starting position when the tone arm islraised.

J. ANDRES.

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