US2662121A

US2662121A - Multiple stylus pickup

Info

Publication number: US2662121A
Application number: US99086A
Authority: US
Inventors: Clarence F Jensen
Original assignee: Webster Electric Co Inc
Current assignee: Webster Electric Co Inc
Priority date: 1949-06-14
Filing date: 1949-06-14
Publication date: 1953-12-08
Anticipated expiration: 1970-12-08

Description

Dec. 8, 1953 c. F. JENSEN 2,662,121

- MULTIPLE STYLUS PICKUP v Filed June 14, 1949 2 Sheets-Sheet l ZZ 50 1 0 JZ @l I I MNQW Dec. 8, 1953 Filed June 14, 1949 C. F. JENSEN MUL'LIPLE:y STYLUS PICKUP 2 sheets-sheet 2 J6 y@ J9' 1%; 15@

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f CZQJ'enceZ/nem I BY 10M/M Ww Patented ec. 8, 1953 MULTIPLE STYLUS PICKUP Clarence F. Jensen, Racine, Wis., assigner to Webster Electric Company, Racine, Wis., a corporation of Delaware Application June 14, 1949, Serial N o. 99,086

The present invention relates to a pickup and has for` one of its primary objects the provision of a new and improved transducer which is especially suited for use as an electric pickup usable in the reproduction of sound yfrom records.

Another object of the present invention is the provision of a new and improved transducer characterized by its small size, lightness, excellent characteristics, simplicity and rugged construction.

A further object of the present invention is to provide a new and improved pickup of the crystal type and which is especially adapted for use with a plurality of styli, such as one for use with conventional records and another for use with long playing records.

A further object of the present invention is to provide a new and improved pickup in which a transducer element, which, as indicated above, may be of the crystal type is substantially entirely surrounded by an envelope of damping material.

A further object of the present invention is to provide a new and improved pickup comprising novel and simple means for holding the crystal in a housing.

A further object of the present invention is to provide a new and improved stylus holding means or chuck which is particularly adapted for use with a plurality of needles.

Another object of the present invention is the provision of a new and improved pickup having good tracking, a good low response and sumcient damping to give a smooth frequency response.

Other objects and advantages of the` present invention will become apparent from the ensuing description of an illustrative embodiment thereof, in the course of which reference is had to the accompanying drawings, in which Figs. 1 and 2 are enlarged elevational and top plan views of a transducer constructed in accordance with the present invention, the transducer being a multi-stylus pickup and the means for attaching the pickup to a tone arm being shown in phantom;

Fig. 3 is a longitudinal horizontal `cross sectional View through the pickup taken along line 3--3 of Fig. 1;

Fig. 4 is a longitudinal vertical cross sectional View taken along the line 4 4 of Fig. 2;

Fig. 5 is an enlarged vertical cross sectional view taken along the line 5-5 of Fig. 2;

Fig. 6 is an enlarged plan view of the envelope for the transducer element;

Fig. 7 is an enlarged side elevational view of the envelope;

16 Claims. (Cl. 179-100.111)

Fig. 8 is a fragmentary enlarged side elevational view of the transducer element-chuck assembly prior to the placing of the envelope thereon; and

Fig. 9 is a fragmentary plan view of the transducer element-chuck assembly shown in Fig. 8.

Referring now to the drawings and first particularly to Figs. 1 to 4, inclusive, it may be noted that the transducer of the present invention is illustrated as being a pickup indicated generally by reference character IG. It comprises a housing l2 including opposed identical sections I4 and i6 secured together in suitable manner as by rivets I8 which pass through reduced width end portions of the housing. The housing sections may be made of suitable material, such as plastic.

The pickup illustrated is of the multiple needle type for playing records of diierent types, such as conventional and long playing records. It includes a stylus 2'for playing conventional records and a second stylus 22 for playing the longplaying records. These styli may be of desired construction. As illustrated, each includes an osmium tipped length of wire securely fastened to a shank 24 having a flat surface 2t for properly positioning the needle in securing means of novel construction to be described hereinafter.

The styli project beyond the housing so that they may be selectively positioned to engage a record. According to one arrangement the pickup can be supported for rotation, as by the angelike supports 28 (shown in phantom only), in a tone arm (not shown) so that one or the other of the styli extends downwardly for engagement with a record placed on a turntable. The means for so rotatably securing the pickup to the tone arm forms no part of the present invention and is therefore not shown.

The housing is constructed with structure, which may be integral with housing sections, for protecting the styli against damage in the event excessive pressure is applied to the pickup o1' tone arm. This structure includes outwardly extending longitudinal bosses 30 at opposite sides of the openings 32 through which the stylus Shanks project into the interior of the housing. The bosses denne, in effect, a longitudinal extending slot 34 in which the major portion of a stylus is located, as may be readily noted from Figs. 1, 2 and 4. The openings 32 are formed by opposed indentations or slots in the abutting sides of the housing sections.

One of the main features of the present invention is the provision of a small, compact and rugged pickupand this is facilitated by arrang-y ing the pickup unit or cartridge, as it is often called, so that it is disposed edgewise When thus arranged, the pickup can be made to have an overall length of 1 inch, a height of inch at its highest part, and still have a transducer element 36 of suicient size to provide the desired electrical output. In the illustrated device, the transducer element is of the crystal type and has connected to it the terminal strips 31 leading to terminal pins 3B. The terminal pins are secured to the housing by their iianged ends 40 which are received in opposed recesses 42 in the housing sections, as best illustrated in Fig. 4.

In accordance with another feature of the present invention, the crystal has attached to its free end a novel chuck adapted particularly for holding a plurality of styli. The chuck, which is indicated as a whole by reference character 44, is stamped from some suitable resilient material, such as beryllium copper. Referring now more particularly to Figs. 5, 8 and 9, the chuck is shown constructed from a single piece of metal having a crystal embracing U-shaped rear portion composed of a generally vertical ilat bight d, `opposed rearwardly extending armsl 48 and the reversely bent forwardly extending portions 50 terminating in the curved chuck defining portions 52 separated by a vertical slot 55. The cuter ends of the stylus receiving portions are flared as indicated by the reference character 56 to facilitate insertion of the stylus Shanks and the flat surface of the bight lit cooperates with the flat surfaces 26 of the stylus Shanks properly to locate the styli in the chucks while the curved chuck portions 52 frictionally hold the styli in The upwardly extending crystal engaging arms i3 and 5t are formed so that their free ends normally extend toward each other a distance less than the thickness of the crystal, so that when the crystal is placed between them it is held resiliently. This normal position is shown in phantom in Fig. 9. ln order to even more positively hold the crystal, the chuck may be cemented to it.

In accordance with another feature of the present invention and one which improves the response characteristics of the pickup and simplies construction and assembly, the crystal-chuck assembly is substantially entirely encased in an envelope Sii made of resilient damping material, such as rubber or rubberlike materials, and best illustrated in Figs. 6 and '7. The envelope covers the crystal and also that portion of the chuck which embraces the crystal. The held end of the envelope may be cut away somewhat at the top and bottom, as indicated by reference characters z2, see Figs. 6 and '7, better to t that portion of the housing structure engaging and holding it and to reduce the compression of the envelope to a desired value.

The envelope, in accordance with a further feature of the present invention, is utilized in securing one end or the crystal. For this purpose the envelope is extended beyond the end of the crystal and the hollow in the extending part is filled by a plug 66 which may be made of the' same material as the envelope and is inserted into it. The envelope is securely held by the opposed inwardly extending bosses 68 of the housing sections which secure the envelope and thus the crystal with a desired and predetermined force when the housing sections are riveted together. When the crystal is thus secured the major portion of the crystal is left substantially free to bend in response to movements of the needle which follows the record grooves. The stylus carrying or free end of the crystal-envelope assembly is in a chamber but the envelope may be and is shown in contact with the chamber side walls. The contact is relatively light to reduce resistance to bending of the crystal, although the envelope can be compressed if certain response characteristics are desired. In the illustrated embodiment the end of the crystal extends a short distance into the space between the bosses 68. This distance can be varied and,

if desired, the end of the crystal may be located short of the bosses, to obtain desired characteristics. The terminal strips 3l are also insulated by the envelope and plug and the plug serves better to hold the strips in place as the latter pass between the plug and envelope. If desired the strips can be wound around the plug.

From the foregoing detailed description of the invention it will be apparent that a pickup can be constructed simply and economically and that it is small in sise and light in weight. It is substantially damage proof and will operate satisfactorily under various conditions. It is particularly adapted for use with a plurality of styli which can be readily and detachably inserted into the double ended chuck. The styli are also protected against damage by the exterior bosses dening slot in which all but the points are located. The pickup of the present invention is characterized by a smooth frequency response and good tracking. The mounting of the crystal is not unduly rigid so that good tracking results, yet it is such as to provide good low response and the damping provided by the envelope smooths undesired light peaks.

While the present invention has been described in connection with the details of an illustrative embodiment it should be understood that the details are not intended to be limitative of the invention except insofar' as set forth in the-accompanying claims.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

i. A transducer unit including a transducer element, an open ended envelope of damping material substantially covering and extending beyond one end of the element, and a plug inserted into and substantially closing the extending end of said envelope.

2. A transducer unit including a transducer element, an open ended envelope of damping material substantially covering and extending beyond one end of the element, a plug inserted into the extending end of said envelope, and a housing engaging and holding said envelope 'in the region of said one end of saiclenvelope and plug.

3. A transducer unit including a transducer element, an open ended envelope of damping material substantially covering and extending beyond one end of the element, and a housing engaging and holding, said envelope in the region ofv said one end of said envelope and enclosing the same, said housing and envelope being so dimensioned relatively that the envelope engages the housing at the unsecured end of the envelope.

4. A pickup including a housing with a chamber having wide and narrow portions, a transducer element, a unitary envelope substantially entirely covering said transducer element, said element and envelope being secured inside the housing by engagement of said housing with said envelope at the narrow portion of the chamber, and said envelope having a thickness at said wide portion of the chamber such that it contacts the sidewalls of the chamber.

5. A pickup including a flat rectangular transducer element secured at one end, and a chuck secured to the other end of and supported solely by said element, said chuck including structure lying substantially in the plane of and in close proximity to the end of said element and dening stylus receiving openings at the end of said element, there being an opening at each end of the chuck.

6. A pickup of the crystal type including an edge mounted crystal transducer element, and a chuck secured to and supported by and extending substantially the full height of the crystal, said chuck having a slotted stylus receiving opening extending substantially the full length thereof for receiving a stylus at each end.

7. A pickup of the crystal type including an edge mounted crystal transducer element, and a chuck secured to and supported by and extending substantially the full height of the crystal, said chuck having a slotted stylus receiving opening extending substantially the full length thereof for receiving a stylus at each end, and a tongue extending into the opening for eiectively dividing the chuck into two parts and for locating the styli.

8. A pickup of the crystal type including an edge mounted crystal transducer element, and a chuck secured to and supported by and extending substantially the full height of the crystal, said chuck having a longitudinally slotted stylus receiving opening extending substantially the full length thereof for receiving a stylus at each end, said chuck also having a central narrow transverse slot for eiectively dividing the chuck into two parts.

9. A pickup including a generally rectangular and thin transducer element, and a thin elongated tubular chuck having approximately the same thickness as the element mounted in the plane of and at and secured to the end of said element, said chuck having aligned stylus receiving openings at each end in close proximity to the element and substantially in the plane of the element, and a substantially central transverse slot providing, in eiect, separate chuck portions for the styli.

10. A multiple needle chuck including resilient longitudinally spaced stylus holding members and a tongue integral with said chuck extending into the space between said members for limiting the extent of insertion of styli.

11. A multiple needle chuck including resilient longitudinally spaced stylus holding members, a tongue extending into the space between said members for limiting the extent of insertion of styli, and a transverse slot effectively separating the chuck into two chuck portions, one for each stylus.

12. A transducer unit of the type including a crystal, an open ended envelope covering at least 6 part of the crystal and extending beyond an end thereof, a plug in the end of and closing the extending portion, and electric conductor terminal strips connected to the crystal passing between the plug and envelope.

13. A transducer unit including a transducer element secured at one end, a chuck secured to the other end of said element, said chuck having stylus receiving openings exten-ding in the longer dimension of the end of said element and at each end of said chuck and securing structure engaging the sides of said element, an envelope of damping material substantially covering said element and securing structure and extending beyond the other end of the element, and means clamping said envelope at said other end for holding said element.

14. A pickup including a housing with a chamber having wide and narrow portions, an edge mounted transducer element, a chuck in said wider portion having element securing portions engaging opposite sides of said element for substantially the full height of the element, said chuck also having a slotted stylus receiving opening beyond the end of said element and extending substantially the full height thereof for receiving a stylus at each end, an envelope substantially entirely covering said transducer element and said securing portions, said element and envelope being secured inside the housing by engagement of said structure with said envelope in said narrow portion of said chamber, and said envelope having a thickness at said wide portion of the chamber such that it contacts the sidewalls of the chamber.

15. A transducer unit including a transducer element, an open ended envelope of damping material at least at one end of said element, and means engaging opposite sides of said envelope at said one end for supporting said element.

16. A multiple stylus pickup including a housing having a thickness substantially less than its height, a thin transducer element mounted edgewise in said housing, and stylus means secured to and supported solely by said element and extending from each edge of the housing.

CLARENCE F. JENSEN.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Datey 1,803,275 Sawyer Apr. 28, 1931 1,904,408 Charlin Apr. 18, 1933 2,045,427 White June 23, 1936 2,106,051 Dunning Jan. 18, 1938 2,133,333 Proctor Oct. 18, 1938 2,160,793 Dally May 30, 1939 2,227,574 Creager Jan. 7, 1941 2,326,280 Bauer Aug. 10, 1943 2,328,952 Burt Sept. 7, 1943 2,363,497 Begun Nov. 28, 1944 2,463,109 Jaffe Mar. 1, 1949 2,474,993 Tibbetts July 5, 1949 2,479,894 Andrews Aug. 23, 1949 2,482,212 Rieber Sept. 20, 1949 2,485,137 Brown Oct. 18, 1949 2,518,861 Burtch Aug. 15,-1950 2,547,227 ONeal Apr. 3, 1951 2,570,578 Martin Oct. 9, 1951 2,594,948 Lynch Apr. 29, 1952 2,601,126 Palo et al June 17, 1952 2,617,895 Angle et al Nov. 11, 1952