US2645498A - Pickup arm having a rotatable cartridge with two needles - Google Patents

Description

July 14' 1953 w. MILLER ET AL PICKUP ARM HAVING A ROTATABLE CARTRIDGE WITH' Two NEEDLES Filed Aug. 11, 1948 lll RIIIHHU. I E

snm 0l. MMM M EPMT VE. T Nro A /ALL m@ m J n Ud' Patented July 14, 1953 PICKUP ARM HAVING A ROTATABLE CARTRIDGE WITH TWO NEEDLES Walter Miller and James L. D. Morrison, Benton Harbor, Mich.

Application August 11, 1948, Serial No. 43,636

5 Claims. l

The present invention relates to pick-up units in tone arms for use in playing records and particularly to a unit or cartridge having two needles, one for playing standard records and one for playing fine grooved records, the cartridge being adapted for rotation.

Records as produced to-day have a standard groove that requires a needle having an .003 radius and an operating R.. P. M. of '78, and a fine groove that requires a needle having an .001 radius and having an operating R. P. M. of 331/3.

The approximate needle pressure required on a standard record using an .003 needle varies between to 28 grams. The needle pressure required on a line groove record using an .001 needle requires about a 6 gram pressure.

It is an object of the present invention to provide a cartridge for tone arms having two sets of pick-ups or needles.

Another object of the present invention is the provision of a tone-arm having a cartridge with two pick-ups adapted for rotation in the tonearm.

A still further object of the present invention is the provision in a tone arm for pivotally mounting a cartridge.

A still further object of the present invention is the provision of means on a cartridge for rotatively moving the cartridge.

A still further object of theV present invention is t e provision of means in the tone arm for regulating' needle pressure.

A still further object of the present invention is the provision of means for holding a cartridge in place in either playing position.

A still further object of the present invention is the provision of means pivotally mounted and carrying resilient pressure means.

With these and other objects in View, the invention consists in the novel construction, arrangement and formation of parts as will be hereinafter more specifically described, claimed and illustrated in the accompanying drawing ;v in which:

Figure 1 is a bottoni plan View of a tone armv and illustrating the cartridge and associated mechanism mounted therein.

Figure 2 is a longitudinal sectional View of Figure l showing the internal arrangement of parts, and the position of the tensioning spring for one of the needles in playing position.

Figure 3 is a view similar to Figure 2 and illustrating the position of the tensioning spring for the other of said needles in playing position,

a portion of the cartridge supporting bracket being shown in full lines.

Figure 4 is a transverse sectional view taken on line 4-4 of Figure l.

Figure 5 is a transverse sectional view taken on line 55 of Figure 2 and illustrating the holding or locking means for the cartridge.

Figure 6 is a vertical sectional view taken on line 6 6 of Figure 5.

Figure 7 is a fragmentary top plan view showing a portion of the cartridge and tensioning spring in a diiierent position than that shown in Figure 1.

Figure 8 is an end elevational view of the tone arm illustrating the means for rotating the cartridge.

Referring to the drawing in detail wherein similar reference characters designate corresponding parts throughout the several views, the numeral I0 represents a tone arm housing having a plurality of lugs II that are integrally formed therewith, and each lug is provided with an internally threaded bore I2, the end I3 of the tone arm housing having an aperture I4, the end I5 of the tone arm having integrally formed bearings or sockets I5 having a bore Il.

Superposed upon the lugs II is a stiilener plate I8 having a plurality of apertures I9 that are in alignment with the bores I2. The plate I8 is securely held on the studs by screws 20, the portion 2l of the plate being bent atvright angles providing a raised portion 22, the raised portion having a depending end portion 23, the bottom portion of which is semi-circular, and a depending side portions 24 that serves as a retaining and guide means. The depending portion 23 is provided with a central aperture 25 and two smaller openings 25 for a purpose to be later described. Mounted to the raised portion 22 by a pin 21 is a roller 28 that is adapted for rotative movement.

Mounted between the depending end portion 23 and the end I3 of the tone arm housing I0 is a plate 29 that is deformed, providing a portion 30 and an oset portion 3l, one end 32 of the plate being bent at right angles to the portion 3U and provided with an aperture 33, detents or semi-circular raised elements 60, and a right angularly formed ear 34 having an aperture 35. The oset portion 3l is provided with a portion 35 that is bent at right angles thereto. and a portion 3T of reduced width that is bent at right angles to the portion 36. The plate 29 is supported at one end by a rivet 38 that engages the aperture 33 and the aperture 35, the rivet being provided with a Washer 3Q. Interposed between the inner face of the portion S2 and the Washer 558 is a spring iii that encompasses the rivet and assists in holding the portion 32 in locking engagement to the depending portion The opposite end of plate 26 is supported by the shank di of a handle or knob the shank having a groove that is engaged by the portion Fixedly secured to the plate 2li by any suitable means is a pick-up cartridgefnl having a needle i5 of an .003 radius, and a needle of an .001 radius. In the opposite end oi the tone arm is a suspension plate il having a tubular portion and a pair of arms i9 each having a bore. The element is held in the tone arm housing by a pin Elli. interposed between the arms and encompassing the pin is a tortion spring 5i, one end or leg E2 or the spring impinging the bottom face of the suspension plate di, the opposite end 53 of the spring being provided with a loop sii. @ne end of cable is connected to the loop Eli, the cable extending to the iiange and having its end connectedfin aperture the cable being trained around the roller se and held engagement by the depending portion 2li.

In the operation of the device the cartridge if, carrying needles iii and it being pivotally mounted may be rotated 180 by the knob i2 toselect the desired needle to play a record. As shown in Figures 1 and 2 theneedle having an .001 radius is in position to play a nne groove record. The cable 5t that is guided around the roller 23 has the proper amount ci pressure of 6 grams, the pressure being supplied by the tortion spring 5i through the arm t3 that is connected to the cable 56. In the position shown in Figures 1 and 2, the cartridge is held in playing position by the studs Slthat are in locking engagement with the apertures or openings (as shown in Figures 5 and 6) in the depending element the depending end S2 of plate being assisted in locked engagement with the depending portion 2S by spring all. v

If it is desired to place needle i5 having an .903 radius in position to play a standard groove record the knob i2 is turned 180 clockwise at which point the studs Sii enter the openings 2t. As shown in Figure 3 the needle i5 is in playing position, the cable during movement of the knob i2 and plate Eil is pulled forward by movement of plate 29 and flange 35i as shown by dotted lines in Figure 7, the arm Ell of the spring assuming the position as shown in Figure 3, the proper gram pressure between Si@ and 2S through the oating element il to which end of the spring is in engagement.

Obvious modifications in the form and arrangement of parts as illustrated may be made Without departing from the spirit and scope of this invention, as defined in the appended claims.

What is claimed is:

` l. In a sound reprodueer an elongated pickup arm mounted adjacent one end to move about a horizontal axis under the influence of gravity, restraining means mounted to move aboutthe horizontal axis ior yieldingly restraining the movement of said arm under the'iniiuence of gravity, diametrically opposed record engaging needles mounted in said arm remote vfrom the supported end thereof for movement about an axis which intersects the horizontal axis into and out of record engaging position, and iiexible means connected to the needles and to the restraining means for altering the effort of the restraining means on the arm. as the needles are moved into and out of record engaging position.

2. In a sound reproducer an elongated pickup arm mounted adjacent one end to move about a horizontal axis `under the inuence of gravity, restraining means mounted to move about the horizontal axis for yieldingly restraining the movement of said arm under the influence of gravity, a needle cartridge mounted in said arm remote from the horizontal axis for rotation about an axis which intersects and lies perpendicular to the horizontal axis, diametrically opposed needles carried by said cartridge and lying perpendicular to the perpendicular axis, and flexible means connected to the cartridge adjacent one side thereof and to the restraining means for altering the restraining effort of the restraining means on the pick-up arm as the cartridge is r0- tated about the perpendicular axis relative to the pick-up arm.

3. In a sound reproducer an elongated pickup arm mounted adjacent one end to move about a horizontal axis under the inuence of gravity, restraining means mounted to move about the horizontal Yaxis for yieldingly restraining the movement of said arm under the influence or" gravity, a needle cartridge mounted in said arm remote from the horizontal axis for rotation about an axis which intersects and lies perpendicular to the horizontal axis, diametrically opposed needles carried by said cartridge and lying perpendicular to the perpendicular axis, a guide roller carried by the pick-up arm adjacent the cartridge for rotation about an axis which lies to one side of and perpendicular to the perpendicular axis and a cable connected to the cartridge adjacent one side thereof and to the restraining means and Ycontacting the periphery of the guide roller for altering the restraining eiort of the restraining means on the pick-up arm as the cartridge is rotated about the perpendicular axis.

Ll. In a sound reproducer a suspension plate, a pi .r-up arm mounted on the suspension plate to move about a horizontal axis under the iniiuence of gravity, a tortion spring encircling the horizontal axis, an arm carried by the tortion spring and engaging the suspension plate to arrest rotation or" said spring about the horizontal axis, a restraining arm carried by the tortion spring for yieldingly restraining the movement of the pickup arm under the influence oi gravity, a needle cartridge mounted on the pick-up arm remote from' the suspension plate for rotation about and longitudinal movement along an axis which lies perpendicular to the horizontal axis, record engaging needles carried by and projecting outwardly from opposite sides of the needle cartridge, detente carried by the needle cartridge on opposite sides of the perpendicular axis and cooperating with the pick-up arm in holding one or the other needle in record engaging position, a guide roller carried by the pick-up arm to one side of the perpendicular axis and adjacent the needle cartridge, and a exible member connected to the restraining arm and to the needle cartridge on one side of the perpendicular axis for altering the effort of the restraining arm on the pick-up arm as the needle cartridge is rotated about the perpendicular axis and a needle is moved into record engaging position.

5. The structure dened in claim 3 in which a shank is carried by the needle cartridge and projects longitudinally from the pick-up arm,

and a knob is carried by the shank remote from the pick-up arm for rotating the shank and the needle cartridge about the perpendicular axis.

WALTER MILLER. JAMES L. D. MORRISON.

References Cited in the le of this patent UNITED STATES PATENTS Number Number Number Name Date Matson Oct. 23, 1917 Bender Oct. 25, 1921 Dunning Aug. 4, 1931 Thomas Feb, 26, 1935 Wielage July 13, 1937 Goldsmith Apr. 5, 1938 Dann June 1, 1943 FOREIGN PATENTS Country Date France Sept. 13, 1913

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