Magnetic recording/reproducing apparatus for recording onto or reproducing from a magnetic tape

Abstract

A magnetic recording/reproducing apparatus for recording onto or reproducing from a magnetic tape housed in a cassette by using a rotary magnetic head having a tape withdrawal arrangement for winding a portion of the tape between the two reels in the cassette around the rotary magnetic head by a predetermined angle. A tape drive feed the magnetic tape at a constant speed, with a reel drive being provided for driving either one of the two reels so as to take up the magnetic tape in the reel driven by the reel drive, and with brake arrangement for braking the rotation of the reels. A ring-shaped cam operating member is provided in the outer peripheral surface or the inner peripheral surface thereof with cam surfaces each for effecting the operation of the respective elements in response to the mode of operation of the magnetic recording/reproducing apparatus. The selective operation is specifically determined by the rotational position of the ring-shaped cam operating member, and the rotational position is varied in response to the mode of operation. A detector is provided for detecting the rotational positions in the ring-shaped cam operating member.

What is claimed is: 
     
       1. A magnetic recording/reproducing apparatus including: a plurality of reel supports for supporting reels of a cassette with a tape-shaped recording medium wound on said reels;   a magnetic rotary head;   means for withdrawing said tape-shaped recording medium out of said cassette, winding the withdrawn recording medium on said magnetic rotary head and guiding said recording medium along a predetermined tape feeding path;   a capstan;   a pinch roller movable from an inoperative position to an operative position to cooperate with said capstan to pinch said recording medium therebetween when said recording medium is in a first running condition;   reel driving means including an idler gear movable from an inoperative position to an operative position to drive one of said reel supports when said recording medium is in a second running condition;   reel support braking means including brake shoes movable from an inoperative position to an operative position to brake rotations of said reel supports when said recording medium is in a third running condition;   operating members independently provided for said pinch roller, for said idler gear, and for said brake shoes for moving said pinch roller, said idler gear and said brake shoes between said operative positions and said inoperative positions, respectively, said operating members being respectively provided with cam followers;   a ring-shaped cam member having cam surfaces formed on radially inner and outer peripheries thereof, said cam followers being respectively operatively associated with said cam surfaces of said ring-shaped cam member so that when said ring-shaped cam member is rotated, said cam followers are respectively actuated by said cam surfaces whereby said pinch roller, said idler gear and said brake shoes are respectively moved from one of said two positions to the other.[...]..Iadd.;.Iaddend.   driving means including a single motor means for driving said tape withdrawing means and said ring-shaped cam member; and power transmission means for transmitting the torque of said motor means to said tape withdrawing means and said ring-shaped cam member intermittently in a timed relationship with the movements of said operating members, said power transmission means including a driving ring disposed in a superposed relationship with said ring-shaped cam member and having a rack formed along a part of at least one of inner and outer peripheral surfaces of said driving ring. .[.2. A magnetic recording/reproducing apparatus according to claim 1, further comprising driving means including a single motor means for driving said tape withdrawing means and said ring-shaped cam member, and power transmission means for transmitting the torque of said motor to said tape withdrawing means and to said third ring-shaped cam member intermittently in a timed relationship with the movements of   
     
     
        said operating members..]. 3. A magnetic recording/reproducing apparatus according to claim 1, further including a substantially circular chassis having a diameter substantially the same as a diameter of said ring-shaped cam member and carrying thereon all elements of the magnetic recording and 
     
     
        reproducing apparatus. 4. A magnetic recording/reproducing apparatus according to claim .[.2.]..Iadd.1.Iaddend., wherein said power transmission means .Iadd.further .Iaddend.includes a .[.driving ring disposed in a superposed relationship with said ring-shaped cam member and has a rack formed along a part of one of an inner and outer peripheral surface of said driving ring;.]. reduction gear means drivingly connected to said single motor means and including a second gear disposed in meshing engagement with said rack to transmit a torque of said motor to said driving ring; transmission gear means drivingly connected to said tape withdrawing means and including a third gear engageable with said rack to transmit the torque of said driving ring to said tape withdrawing means during a time period when said third gear is engaged with said rack; an elongated hole formed in one of said ring-shaped cam member and said driving ring; and a pin means mounted on the other of said ring-shaped cam member and said driving ring and adapted to be received in said elongated hole to transmit the torque of said driving ring to said ring-shaped cam member during a time period when said pin means is engaged with an end of 
     
     
        said elongated hole. 5. A magnetic recording/reproducing apparatus according to claim 3, further including means for detecting a rotational 
     
     
        position of said ring-shaped cam member relative to said chassis. 6. A magnetic recording/reproducing apparatus according to claim 5, wherein said detecting means includes a pin mounted on one of said ring-shaped cam member and said chassis and a slide switch disposed in sliding engagement with said pin and mounted on the other of said ring-shaped cam member and 
     
     
        said chassis. .Iadd.7.  A magnetic recording/reproducing apparatus including: reel driving means for rotatably driving reels in a cassette accommodating a tape-shaped recording medium wound on said reels;   tape driving means for feeding said tape-shaped recording medium;   reel braking means for braking said reels;   rotary cylinder means having magnetic head means;   means for drawing out said tape-shaped recording medium from said cassette, winding the drawn out tape-shaped recording medium on said rotary cylinder means and guiding the drawn out tape-shaped recording medium along a predetermined path;   operating means operatively associated with at least one of said tape driving means, said reel driving means and said reel braking means to switch said at least one of said tape driving means, said reel driving means and said reel braking means from one of operative and inoperative positions to the other;   driving motor means;   driving gear means driven by said driving motor means and including a driving gear;   means for transmitting torque of said driving gear to said drawing-out means and to said operating means;   said torque transmitting means including an arcuate rack engaged with said driving gear, cam means and a driven gear engageable with said rack;   wherein said arcuate rack and said cam means are rotatable by said driving gear about a common axis of rotation, said cam means are operatively associated with said operating means to actuate said operating means when said cam means are rotated by said driving gear about said common axis of rotation, and said driven gear is spaced from said driving gear in a rotational direction of said arcuate rack and operatively connected to said means for drawing out to transmit the torque of said driving gear to   
     
     
        said means for drawing out..Iaddend. .Iadd.8.  A magnetic recording/reproducing apparatus according to claim 7, wherein said torque transmitting means further include a ring-shaped cam member having peripheral surfaces, said cam means comprising cam surfaces formed in at least one of the peripheral surfaces of said ring-shaped cam member, a ring-shaped transmission member concentric to said ring-shaped cam member and having a substantially circular periphery formed thereon with said arcuate rack, and means for drivingly connecting said ring-shaped transmission member to said ring-shaped cam member..Iaddend. .Iadd.9. A magnetic recording/reproducing apparatus according to claim 8, wherein said means for drivingly connecting comprises a lost-motion 
     
     
        connection..Iaddend. .Iadd.10.  A magnetic recording/reproducing apparatus according to claim 8, wherein said ring-shaped transmission member has a cylindrical surface following said rack as viewed in a circumferential direction of said ring-shaped transmission member, and wherein said torque transmitting means further includes means fixed to said driven gear so as to be engageable with said cylindrical surface after said driven gear has been rotated in one direction by said ring-shaped transmission member, to prevent said driven gear from being rotated in an opposite direction..Iaddend. .Iadd.11. A magnetic recording/reproducing apparatus according to claim 8, further including a circular chassis having a diameter substantially the same as a diameter of said ring-shaped cam member and accommodating the same and said ring-shaped transmission member therein..Iaddend. .Iadd.12. A magnetic recording/reproducing apparatus according to claim 8, wherein said cam surfaces are spaced from each other in the rotational direction thereof and wherein said operating means comprise a plurality of independent operating members operatively associated with said tape driving means, said reel driving means and said reel braking means to switch said tape driving means, said reel driving means and said reel braking means from one of operative and inoperative positions to the other, respectively..Iaddend.