Cartridge for detecting vibrations representing stereophonic sound

Claim 2

An electromagnetic stereophonic pickup cartridge for stereophonic reproduction of sound from a record groove having individual sound recordings disposed according to the 45*-45* system, comprising electromagnetic generating means having two independently variable magnetic air gaps located at opposite sides of an imaginary first vertical plane and aligned in an imaginary second vertical plane transverse to said first plane; a cantilever arm having one end portion provided with a stylus, another end portion, and a longitudinal axis coincident with said first plane; magnetic armature means carried by said other end portion and being located in said second plane; magnetic means fixedly mounted proximal to said armature means for magnetizing the same; and mounting means engaging said other end portion of said cantilever arm and mounting the same for movement in more than one plane at substantially equal degrees of restraint about a fulcrum which is located at least proximal to said second plane; said mounting means comprising an elongated flexible portion and an armature carrying portion, said portions of said mounting means being unitary and composed of synthetic plastic resin material.

Claim 3

A multichannel pickup cartridge adapted for simultaneous reproduction of multichannel signals from a record disk having a groove with two modulated walls comprising: an enclosure having an open window in its bottom; electromagnetic means including two pairs of pole pieces forming a pair of mutually independent air gaps, respectively, which are located on opposite sides of a first imaginary vertical plane and aligned in a second imaginary vertical plane which intersects with said first vertical plane; a cantilever arm having its longitudinal axis coincident with said first imaginary vertical plane, said pole pieces of each pair being spaced axially of said arm; an armature securing member securedly connected to said cantilever arm at the other end thereof; a pair of armatures secured to said securing member, each said armature being disposed within each of said air gaps at an angle of inclination corresponding to the respective modulated wall of said sound groove of said record disk; socket means fixed within said enclosure, said socket means including a recess opposite said window; a knob member of non-magnetic material; securing means for replaceably securing said knob member in the recess in said socket means, said knob member being channel-shaped in section so as to cooperate with said socket means to substantially cover said window when secured in place, said knob member being formed with a bore which extends through the central portion of said knob member in a direction inclined with respect to the bottom of said enclosure; a mounting member located in said bore; further securing means for adjustably securing said mounting member in the bore; fulcrum means having its one end secured to the other end of said cantilever arm and its other end extending through and secured to said mounting member; and a damper of an elastic material placed between the other end of said cantilever arm and said knob member; said fulcrum means extending through said damper and being tensioned so as to maintain said damper in abutting relationship with said knob member and the rear end of said cantilever arm, whereby the knob member carries said cantilever assembly including said cantilever arm and said armatures thereon; said electRomagnetic means being responsive to a change in magnetic flux produced in said air gaps by a motion imparted by the record disk to said stylus tip and thence to said armatures.

Claim 4

A multichannel pickup cartridge adapted for simultaneous reproduction of multichannel signals from a record disk having a groove with two modulated walls comprising: an enclosure having an open window in its bottom; electromagnetic means including two pairs of pole pieces forming a pair of mutually independent air gaps, respectively, which are located on opposite sides of a first imaginary vertical plane and aligned in a second imaginary vertical plane which intersects with said first vertical plane; a cantilever arm having its longitudinal axis coincident with said first imaginary vertical plane, said pole pieces of each pair being spaced axially of said arm; an armature securing member securedly connected to said cantilever arm at the other end thereof; a pair of armatures secured to said securing member, each said armature being disposed within each of said air gaps at an angle of inclination corresponding to the respective modulated wall of said sound groove of said record disk; socket means fixed within said enclosure, said socket means including a recess opposite said window; a knob member of non-magnetic material; securing means for replaceably securing said knob member in the recess in said socket means, said knob member being channel-shaped in section so as to cooperate with said socket means to substantially cover said window when secured in place, said knob member being formed with a bore which extends through the central portion of said knob member in a direction inclined with respect to the bottom of said enclosure; a mounting member located in said bore; further securing means for adjustably securing said mounting member in the bore; fulcrum means having its one end secured to the other end of said cantilever arm and its other end extending through and secured to said mounting member; and a damper of an elastic material placed between the other end of said cantilever arm and said knob member; said fulcrum means extending through said damper and being tensioned so as to maintain said damper in abutting relationship with said knob member and the rear end of said cantilever arm, whereby the knob member carries said cantilever assembly including said cantilever arm and said armatures thereon; said electRomagnetic means being responsive to a change in magnetic flux produced in said air gaps by a motion imparted by the record disk to said stylus tip and thence to said armatures.

Claim 5

A multichannel pickup cartridge according to claim 2 wherein said modulated walls are each inclined at an angle of 45* with respect to the vertical and at right angles to each other.

Claim 6

A multichannel pickup cartridge according to claim 2 in which said armature securing member, said fulcrum means and said mounting member are all integrally formed by casting resin, the ends of said armatures and said cantilever arm being embedded in the securing member thus formed.

Claim 7

A multichannel pickup cartridge according to claim 4 wherein said securing member is provided with a projection on one end thereof and in which said cantilever arm has a bore, said projection engaging said bore.

Claim 8

A multichannel pickup cartridge adapted for simultaneous reproduction of multichannel signals from a record disk having a groove with two modulated walls comprising: an enclosure having an open window in the bottom; electromagnetic means including two pairs of pole pieces forming a pair of mutually independent air gaps, respectively, which are located on opposite sides of a first imaginary vertical plane and aligned in a second imaginary vertical plane which intersects with said first vertical plane; a cantilever arm having its longitudinal axis co-incident with said first imaginary vertical plane, said pole pieces of each pair being spaced axially of said arm; a stylus tip adapted to engage said sound groove, said stylus being supported at one end by said cantilever arm; an armature securing member securedly connected to said cantilever arm at the other end thereof; a pair of armatures secured to said securing member, said armatures being of a high magnetic permeability material and disposed within each said air gap at an angle of inclination corresponding to the respective modulated wall of said sound groove of said record disk; a permanent magnet fixedly disposed within said enclosure adjacent said armatures for magnetization thereof; socket means fixed within said enclosure, said socket means including a recess opposite to said window; a knob member of non-magnetic material; securing means for replaceably securing said knob member in said recess in said socket means, said knob member being channel-shaped in section so as to cooperate with said socket means to substantially cover said window when secured in place, said knob member being formed with a bore which extends through the central portion of said knob member in a direction inclined with respect to the bottom of said enclosure; a mounting member located in said bore; further securing means adjustably securing said mounting member in said bore; a fulcrum having its one end secured to the other end of said cantilever arm and its other end extending through and secured to said mounting member; and a damper of an elastic material placed between the other end of said cantilever arm and said knob member; said fulcrum extending through said damper and being tensioned so as to maintain said damper in abutting relationship with said knob member and said rear end of said cantilever arm, whereby said knob member integrally carries said cantilever assembly including said cantilever arm and said armatures thereon; said electromagnetic means being responsive to a change in magnetic flux produced in said air gaps as derived from the permanent magnet through said armatures, said change being caused by a motion imparted by said record disk to said stylus tip and thence to said armatures.

Claim 9

A multichannel pickup cartridge adapted for simultaneous reproduction of multichannel signals from a record disk having a groove with two modulated walls comprising: an enclosure having an open window in the bottom; electromagnetic means including two pairs of pole pieces forming a pair of mutually independent air gaps, respectively, which are located on opposite sides of a first imaginary vertical plane and aligned in a second imaginary vertical plane which intersects with said first vertical plane; a cantilever arm having its longitudinal axis co-incident with said first imaginary vertical plane, said pole pieces of each pair being spaced axially of said arm; a stylus tip adapted to engage said sound groove, said stylus being supported at one end by said cantilever arm; an armature securing member securedly connected to said cantilever arm at the other end thereof; a pair of armatures secured to said securing member, said armatures being of a high magnetic permeability material and disposed within each said air gap at an angle of inclination corresponding to the respective modulated wall of said sound groove of said record disk; a permanent magnet fixedly disposed within said enclosure adjacent said armatures for magnetization thereof; socket means fixed within said enclosure, said socket means including a recess opposite to said window; a knob member of non-magnetic material; securing means for replaceably securing said knob member in said recess in said socket means, said knob member being channel-shaped in section so as to cooperate with said socket means to substantially cover said window when secured in place, said knob member being formed with a bore which extends through the central portion of said knob member in a direction inclined with respect to the bottom of said enclosure; a mounting member located in said bore; further securing means adjustably securing said mounting member in said bore; a fulcrum having its one end secured to the other end of said cantilever arm and its other end extending through and secured to said mounting member; and a damper of an elastic material placed between the other end of said cantilever arm and said knob member; said fulcrum extending through said damper and being tensioned so as to maintain said damper in abutting relationship with said knob member and said rear end of said cantilever arm, whereby said knob member integrally carries said cantilever assembly including said cantilever arm and said armatures thereon; said electromagnetic means being responsive to a change in magnetic flux produced in said air gaps as derived from the permanent magnet through said armatures, said change being caused by a motion imparted by said record disk to said stylus tip and thence to said armatures.

Claim 10

An electromagnetic cartridge as defined in claim 6, said permanent magnet means being located at a side of said armature means and said second plane which is remote from said stylus, and comprising a guide pole portion extending towards said armature means.

Claim 11

An electromagnetic cartridge as defined iN claim 6, said permanent magnet means being located above said armature means, and comprising a guide pole portion extending towards said armature means.

Claim 12

An electromagnetic cartridge as defined in claim 6, said permanent magnet means comprising a first permanent magnet located intermediate said armature means and said stylus, and a second permanent magnet located above said armature means.

Claim 13

An electromagnetic cartridge as defined in claim 6, said permanent magnet means being located intermediate said armature means and said stylus; and further comprising an auxiliary armature also located intermediate said armature means and said stylus and being carried by said cantilever arm.

Claim 14

An electromagnetic cartridge as defined in claim 6, said air gaps each being elongated, and said armature means including two elongated armatures each located in one of said gaps and having a longitudinal axis which extends substantially at a right angle to the elongation of the respective gap.