US2513555A - Tone-arm mounting - Google Patents

Description

July 4, 1950 w. J. FAULKNER ToNARM MOUNTING 2 Sheets-Sheet 1 Filed Sept. 14, 1949 5 I?? we?? faz" 9 Wiz/Mifjfmmwf July 4, 1950 w. J. FAULKNER TONE-ARM MOUNTING 2 Sheets-Sheet 2 Filed Sept. 14, 1949 QW@ ,ma M W @alga van? nf fw M@ i@ M a@ 3 -ad W w Z0 Patented July 4, 1950 UNITED STATES PATENT Q'FFICE TONE-ARM MOUNTING Willard J. Faulkner, Chicago, 111 assigner .to Oak Mfg. Co., Chicago, Ill., a, corporation of Illinois Application September 14, 1949, Serial No. 115,615

4 Claims. 1

This invention relates to a tone-arm-mounting and is particularly concerned with the-tone-arm supporting portion of an automatic. record changer. The construction embodying thepresent invention is of generalapplication but is particularly adapted for use `with the record changer` disclosed and claimed in the copending application of Arthur C. Ten Cate, Serial No. 88,213 led April 18, 1949.

The invention in general contemplates a structure whereby the tone-arm portion of an automatic record changer has a simple and eiective hinge and spring mounting so that both horizontal and vertical adjustments of the tone-.arm are easily possible. Furthermore, the structure embodying the present invention provides a shockproof mounting whereby when the tone-arm vis manually moved horizontally against any retaining means on the part of the changer, the tonearm will yield without damage to the mechanism. A particularly desirablefeature of the-invention resides in the fact that the mounting permits tone-arm balance with respect to the horizontal pivots. Thus a small, light tone-arm having low inertia and low needle pressure may be attained. With a tone-arm embodying the invention, the weight of the transducer element provides the necessary needle pressure. Other advantages will occur to those skilled in the art.

In order that the invention may be understood, it will now be explained in connection with the drawings wherein Figure 1 is a top view partly in section of a changer embodying the new tone-arm construction. Figure 2 is a side detail of the tone-arm mounting. Figure 3 is an enlarged sectional side view of the mounting of the tone-arm. Figure 4 is a sectional view generally similar to Figure 3 but showing other parts in section. Figure 5 is a section on broken line 5 5 of Figure 4 with a portion of the tone-arm shown in dotted lines forced out of normal position. Figure 6 is a detail of the mounting removed from the tonearm.

Referring first to Figure l, motor board l0 preferably of pressed steel has circular well H in which is bolted at I3; drive motor I5. The motor has shaft I6 engaging large rubber covered wheel l1 i rotating around axis I8'. Concentric with wheel Il is small rubber drive shaft extending adjacent the depending skirt of turntable 30. This drive is conventional in the art.

Rotatably disposed on spindle 21 and above well il is gear 3|. This gear may have secured thereto suitable means in a turret for supporting a stack of records centrally of the records and feeding. ,the same one at a time on to turntable 39. The precise means ,for supporting and feeding the records is not necessary to a proper kunderstanding of the invention and is therefore not fully disclosed herein. However, an example of such means is ydisclosed and claimed in the Ten Cate application previously referred to. Other recordsupportingmeans may be used as desired.

Gear 3|` is adapted to cooperate with gear 40 rotatively secured at 4| andprovided witha number of cam surfaces and slots. Inasmuch as the details .of this gear construction relate to the record feeding and timing means, no further disclosure thereof will be made except as necessary for a proper understanding of the tone-arm actuatingand elevating means.

Pivotally supported at `45 (Figure 1) in motor board I9 is sleeve 46. This sleeve is supported in bearinglll carried by the motor board. Sleeve 45 is rotatively supported., but is prevented from longitudinall movement, that is'movement vertically, by lany suitable means.

Sleeve 46 carries (Figure-4) at lower en d 59 arm ,51. having fingers 52 and. 53 at the ends thereof for cooperation with the automatic record feeding mechanism. It .isunderstood that armv5l coop'- erates with suitable means for moving the arm over a predetermined angular range and is adapted to control the movement of the tone-arm in a, conventional manner.

Sleeve 46 has its upper end rigidly clamped in a generally U-shaped fixture 55. Fixture 55 has portions 55 and 5l connected together by bight 58. Portions 56 and 57 are suitable apertured and connected by slotted portion to extending around the length of the material along the bight. Bolt 62 is disposed in the bight portion and may be used for tightening the two split portions around the end of the sleeve. Portion 56 has upstanding wing portions 63 and 64. Wing portions 63 and 64 have slotted arms 65 and 66 bent toward each other. 'Ihese two wing portions also have suitable apertures 6l and 58 therethrough. Tail portions 69 and l0 of the wing portions are bent toward each other and have pivotally mounted therebetween rocker 12. Rocker 'l2 has rear portion 13 extending directly over the aligned apertures of the xture.

Disposed in slots 67 and 68 of the bent arms is pivot pin 16 supported by springs Il and 18. Springs 'l1 and I8 are anchored in apertures in wings 63 and 64 and slots 19 and 80 of the pivot pin. The pivot pin has portions extending beyond the slotted wing portions as shown. These two springs may be replaced by one central spring.

The Iassembly of sleeve and mounting fixture is pivotally secured to tone-arm 82 in the following manner. One end of pivot pin 1S extends through aperture 83 in one side Wall of the tonearm. This aperture is just large enough to accommodate the end of pivot pin for proper rocking action. The other end of the pivot pin is Secured in an aperture of pivot support plate 85 adjustably secured at slot 86 to the opposing side of the tone-arm'. Slot 8l in the tone-arm side is provided for accomodating the free end of the pivot pin.

ment of pivot pin support plate 85. Preferably the two slots in the side of the tone arm are wide enough to allow for some vertical adjustment of the tone arm with respect to the pivot pin asi well as lateral adjustment. Rocker 'l2 has end 83 formed as a iin'ger and cooperates with stop plate 99 bolted to the rear side wall of the tone-arm. Preferably, plate Sii is adjustably secured to the tone-arm as by elongated slots in the tone-arm side wall so that the stop plate may be disposed in a desired po` sition prior to tightening the bolts. Stop plate 9U is heavy enough so that it acts as a counter Weight for the tone-arm proper. Thus the tonearm may be balanced at pivot pin 75 for vertical play. Cartridge 92 shown in dotted outline at the yfree end of the tone-arm will then provide the needle pressure necessary for tracking.

Pin 95 vertically movable in sleeve d6 will elevate the tone-arm'. Thus when pin 95 is raised by suitable means at the end of a record playing cycle, it moves rocker l2 against stop 9&1 and forces the tone-arm to raise. Whenpm 95 drops, the tone-arm drops. Actual tone-arm elevation is secured only by raising pin 55 be+ yond the point where finger 88 of rocker 'l2 engages stop SD. The adjustment of stop plate 95 on the tone-arm Will control tone-arm elevation. If desired, a spring may be disposed between end 91 of ixture 55 and aperture 98 in rocker 12;Y Such a spring will reduce the needle pressure.

When ythe tone-arm is forced away from a normal horizontal position, springs Tl and 'I8 It will be noticed that slots 8d and 81 are elongated to allow for some adjustpermit yielding of the tone-arm. This is shown in dotted lines in Figure 5. Upon release of the tone-arm, springs 'll and 18 return the same to its normal position.

What is claimed is:

1. In a phonograph, a tone-arm mounting comprising a fixture having a pair of curved slotted arms, a pivot pin passing through said slots and extending on opposite sides of said iixture, at least one spring anchored to said xture and pin for retaining said pin against said fixture at the ends of the Slots, a sleeve clamped rby said xture, a rocker arm pivotally secured to said fixture and having one end at the sleeve axis, said rocker arm axis being parallel to the pin axis in a normal pin position with the rocker arm and pin axes being spaced on opposite sides of the sleeve axis and perpendicular thereto, a tone-arm, said tone-arm having journals for thepin ends, a stop carried by the tone-arm, and a second pin vertically slidable in said sleeve to engage said one end of the rocker arm, the other endl of Said rocker arm being adapted to engage the stop, said pin serving to move said 'rocker arm and elevate the tone-ann, said spring permitting horizontal deflection of said tonefarm from a normal position.

2,'The structure according to claim lwherein said tone-arm has one of said journals adjustable whereby the horizontal tone-arm position relative to the fixtures may be predetermined.

3. The structure according to claim 1 Wherein the step is secured to the tone-arm and remote from the pick-upend and wherein said 'stop is adjustably secured to said tone-arm Iwhereby the tone-arm elevation may be controlled.

4. The structure according to claim 1 wherein said tone-arm has one pin journal adjustable and wherein said stop is adjustably carried so that horizontal and vertical tone-arm control is obtained.

` WILLARD J. FAULKNER.

No references cited.

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