| 摘要 |
1,270,369. Gramophone. COLUMBIA BROADCASTING SYSTEM Inc. 11 Nov., 1970 [21 Nov., 1969], No. 53709/70. Heading G5R. In a record reproducer in which a pick-up support carriage 31 is mounted for radial movement relative to record 24 and has a pick-up 26 mounted thereon for movement relative to the carriage in the direction of carriage movement, the carriage is driven at a faster speed than that of the pick-up which is driven by the record groove and carriage drive decoupling means are brought into operation when the pick-up moves beyond a predetermined position relative to the carriage. The carriage is mounted on guides 34, 36 and driven by a half nut 62 which engages on eccentrically mounted lead screw 42 driven by friction wheel 44 engaging the record surface. The half nut 62 is mounted on an arm 64 which is spring urged about its pivot 66 towards the lead screw 42 and formed with a cut-out portion 72 and push button 74. Due to the eccentricity of the lead screw mounting, the nut 62 and arm 64 are reciprocated towards and away from the lead screw axis of rotation. The pick-up 26 is mounted on an arm 76 with oppositely directed lateral pivots 78, 80 by which the arm is mounted for pivoting and lateral movement in pillars 86, 88. In operation, due to the difference in pick up and carriage speeds the pick up moves towards pillar 86 moving, via an eye at the end of pivot 78, a spring wire member 90 until its tip enters the cut-out portion 72 of arm 64 as this moves downwardly following the eccentricity of the lead screw thereby disengaging the half nut until the pick-up resumes its initial position relative to the carriage and tangential to the record groove. As the pick-up enters the run-out groove, spring wire 124 is moved by the pick-up into the path of an oscillating lever 126. This then actuates a releasing member 112 which moves a detent portion of a spring 103 from the upper surface of the carriage and a further portion of the spring now engages an extension 100 of the pick-up arm to pivot the pick-up stylus out of engagement with the record. The assembly can be raised by upward pressure on knurled band 60 and swing about pillar 46 to a rest position. The radial position of the assembly is defined by a key 52 on pillar 46 which engages a keyway 54 in the cylindrical member 50 which is fast with the remainder of the assembly. On return of the assembly to the play position, the spring 103 is returned to its initial position to allow the pick-up stylus to engage the record by operation of push button 74. |
