US2326424A - Phonograph stylus - Google Patents

Description

Aug. 10, 1943. 1. J. ANDRES PHONOGRAPH STYLUS Filed April 17, 1943 Patented 10, 1943 2,326,424 PHONOGRAPH STYLUS Lloyd J. Andres, Clilcag Products Corporation,

tion of Illinois 111., assignor to Permo Chicago, 111., a corpora- Applicatlon April 17, 1943, Serial No. 483,466

2 Claims.

This invention relates iii general to phonograph styli and more particularly to improvements in 4 the "offset type styli.

The construction of vious to this invention inherently required greater mass and lacked a secure means for bonding the offset portion to the shank member sufficiently secure to withstand prolonged transmission of vibration. Previous styli of this character usually employed a flat ribbon ofi set member riveted at one end to the end of a conventional shank and a holder riveted at its opposite end for securing the playing tip. Another form of offset styli utilizes a wire of round cross section for the offset portion and a supporting means in the reproducer in contact with the offset portion to sustain the weight of the reproducer.

In the present invention the above objectional riveting and the auxiliary supports are completely overcome through the novel construction of a simple three-piece structure adapted to low cost high production manufacturing methods.

The principal object of in the novel construction whereby the tip which engages the record grooves is offset from a shank permitting a controlled amplitude of movement in both lateral and vertical directions with respect to the shank.

A further object of the invention is the provision of a damping medium for limiting the resonant and/or sustained vibration present in the stylus when playing.

A further object of the invention is the provision of a novel construction for joining a tubular shank with the offset member with a minimum of mass.

Further objects and advantages of the invention will appear in the following description and drawing, in which:

Fig. l is a side elevation of the stylus.

Fig. 2 is a cross-sectional side elevation of the stylus shown Fig. l.

' Fig. 3 is a front end cross-sectional view taken through section lines 3-3, Fig. 1.

Fig. 4 is a top cross-sectional view of the stylus taken through section lines 4-4. Fig. 2.

Fig. 5 is an exploded perspective view of the elements of the stylus shown in Fig. 1, prior to assembly.

Fig. 6 is a fragmentary cross-sectional view of the stylus shown in Fig. 1 taken through section lines 3-3, prior to final forming.

The side view Fig. 1 shows the complete stylus assembly in which a tubular shank I is flattened at the upper end for insertion in a conventional the invention resides styli of the offset type prereproducer or pick-up. The usual fiat portion is provided as a means for locating the stylus in a predetermined position in the pick-up with the offset member of the stylus placed substantially parallel with the record grooves with the tip end facing the oncoming grooves of a moving record.

Referring to Fig. 5, a tubular shank l is provided to minimize mass reactions in operation and is provided with a rectangular slot 5 through the center of its lower end at right angles to the flattened portionon the opposite end of the shank.

The offset member 2 is formed from round wire and provided with an integral wear resistant conical tip 3 for engagement with the record groove. The wire is first bentat 2 to form a small projection terminating at tip 3 for engagement with the record groove substantially vertical to the axis of the conical trip.

The flattened portion 6 in the horizontal portion of the wire is formed to predetermined dimensions whereby predetermined resilience is provided in vertical directions while relatively greater stiffness is provided in one end of the member with a cylindrical portion 9 of the wire therebetween to provide a rigid fastening when assembled into the slot 5 of shank I.

A tube of viscous damping material, such as plasticized cellulose acetate or other similar resilient material, is provided to snugly fit over the horizontal portion of member 2 in close contact with the flattened portion 6. The position of this tube in assembly is clearly shown in Figs, 1, 2 andi.

In assembly, the flattened end of member 2 is fitted into the slot 5 in the shank l as shown in Figs. 2, 4 and 6. It is to be noted that the cylindrical portion 9 is of the same diameter as the original wire and portions of its opposite ends are in contact with the inner surface of the shank l. The flattened portions 1 and 8 are closely fitted in the slot 5.

The next operation in securing the member 2 in tight integral relation with shank l is accomplished by spinning or swaging the slotted end of the shank I into a semi-spherical form 10 shown in Fig. 3. Thus relative movement between the shank and the offset member in any direction is prevented.

In operation, when the stylus is secured in a conventional pick-up and the tip is engaged in the groove of a moving phonograph record, vertical components of motion, which ordinarily are transmitted to the pick-up and are manifest in the reproduction as distortion, are absorbed by the vertical relative movement of tip 3 with respect to the shank.

Vertical vibratory movements normally restricted because of the mass of conventional reproducers and the non-vertical compliance of conventional styli, result .in extraneous distortion being introduced in the reproducer and increased wear between the record and stylus.

The lateral vibrations in the record groove encountered by the tip 3 are transmitted by reciprocating crank action of the offset member to the shank and thus to the pick-up without restriction. The ratio of vertical to lateral stiffness of the oifset member is governed by the amount a particular size wire is flattened. The lateral stiffness is adjusted to a point whereby certain undesirable high frequencies are absorbed by lateral resilience but all other frequencies are freely transmitted through the ofiset member to the shank and thus to the pick-up.

The presence of the damping tube 4 in close contact with the offset member prevents undesirable sustained or prolonged sympathetic vibrations from being set up in the offset member because of the mass and absorption properties of the damping material itself.

Having described my invention, I claim;

1. A phonograph stylus comprising a shank adapted at one end to be secured in a pick-up, an offset portion integrally swaged in the opposite end of said shank, said offset portion including a short portion integral with and extending at an angle to said ofiset portion, said short portion terminating in a record engaging tip, the axes of said shank, offset portion and short portion lying substantially in one plane, said oflset portion flattened in a plane substantially at right angles to said first mentioned plane, a tubular resilient damping means surrounding said oflset portion in close contact therewith, whereby said short portion will vibrate vertically along its axis independently of said shank and whereby resonant and/or sustained vibrations in said short portion will be damped by said damping means when the shank is secured in a pick-up and the said playing tip is engaged in the groove 01' a moving record.

2. A phonograph stylus comprising a tubular shank adapted at one end to be secured in a pick-up, an offset portion integrally swaged into oppositely spaced slots in the ends of said shank, said ofiset portion including a short portion integral with and extending at an angle to said offset portion, said short portion terminating in a record engaging tip, the axes of said shank, offset portion and short portion lying substantially in one plane, the end of said ofiset portion opposite said short portion having two flattened portions parallel to and in spaced relation with each other in swaged engagement with the said oppositely spaced slots in the end of said shank, a tubular resilient damping means surrounding said offset portion in close contact therewith, whereby said short portion will vibrate vertically along its axis independently of said shank and whereby resonant and/or sustained vibrations in said short portion will be damped by said damping means when the shank is secured in a pick-up and the said playing tip is engaged in the groove of a moving record.

LLOYD J. ANDRES.

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