Abstract:
A lock mechanism for locking a head plate and fast-forwarding and rewinding levers of a tape player comprises step-shaped engage portions formed along side margins of the fast-forwarding and rewinding levers near their one end, a lever lock member pivotally mounted near these ends of the levers for releasable locking engagement with the step-shaped engage portions, and a compression portion formed along a margin of the head plate which unlocks the locking engagement between the lever lock member and step-shaped engage portion when the head plate withdraws concurrently with deenergization of a plunger upon detection of a non-signal portion between pieces of music on a tape.

Description:
FIELD OF THE INVENTION 
     This invention relates to a lock mechanism for locking a head plate and fast-forwarding and rewinding operational levers in a tape player having a head movable to and away from a tape. 
     BACKGROUND OF THE INVENTION 
     An inter-music detection mechanism for detecting a non-signal portion between pieces of music on a tape to select a desired piece of music is activated in the fastforwarding (FF) or rewinding (REW) mode of the tape player where a tape slightly contacts a head and is driven at a high speed. When the head detects a non-signal portion on the tape, a plunger which has heretofore maintained the FF or REW mode is deenergized to allow the head to get in close contact with the tape, and the FF or REW lever is withdrawn to detach a high speed idler from a reel base. 
     One of several recent tape players includes a motor-driven head plate which supports a head and is moved upon a mode change from the stop mode to the play mode to bring the head to a predetermined position. In this type of tape player, a specific plunger is used to hold the head plate at its advance position when energized and to unlock the head plate when deenergized upon restoration of the stop mode. 
     However, the prior art lock mechanism using a specific plunger for locking a head plate, when combined with the aforegoing inter-music detection mechanism, require several plungers specifically provided to individual mechanisms, and invites a complicated circuit or switching arrangement for control of the plungers. Additionally, since these plungers are more expensive than other sheet metal members, they inevitably increase the manufacturing cost of the tape player. 
     OBJECT OF THE INVENTION 
     It is therefore an object of the invention to provide a lock mechanism for locking a head plate and FF/REW levers which uses a single plunger not only for locking the head plate at its advance position but also for maintaining the FF or REW lever during inter-music detection, thereby simplifying the construction and reducing the manufacturing cost of the tape player. 
     SUMMARY OF THE INVENTION 
     According to the present invention, there is provided a head plate and fast-forwarding/rewinding lever lock mechanism in a tape player comprising: 
     a head plate carrying a head thereon to bring the head to and away from a tape in the tape player; 
     a plunger energized to hold the head plate at its advance position and temporarily deenergized in response to a signal from the head when the head detects a non-signal portion between pieces of music on the tape; 
     a lock member for locking a fast-forwarding or rewinding operational lever and unlocking same when the lock member is pushed and rotated by the head plate being moved to its withdrawal position; 
     a spring biasing said lever lock member in a direction for locking engagement with said fast-forwarding or rewinding operational lever; and 
     an engagement portion provided on said fastforwarding or rewinding operational lever to engage said lever lock member when said lever is pushed into the tape player. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIGS. 1 through 3 illustrate a head plate and FF/REW lever lock mechanism embodying the invention, in which 
     FIGS. 1 is a plan view of the mechanism in the play mode, 
     FIG. 2 is a plan view of the mechanism during intermusic detection, and 
     FIG. 3 is a plan view of the mechanism on restoration of the stop mode; and 
     FIG. 4 is a side elevation of a lever lock member and other components of the embodiment of FIG. 1. 
    
    
     DETAILED DESCRIPTION 
     The invention is hereinbelow described in detail, referring to a preferred embodiment illustrated in the drawings. 
     As shown in FIG. 1, an FF (fast-forward) lever 1 and a RE (rewind) lever 2 are mounted movably back and forth with respect to a tape player, and they are normally biased by a not illustrated revival spring outward of the tape player (downward in FIGS. 1 through 3). Each lever has near the inner portion thereof a step-shaped engage portion 3 or 4 for engagement with a lock member 5 when inserted deep into the tape player. The lock member 5 is mounted near the inner ends of the FF and REW levers 1, 2 pivotably about an axis 6 for engagement with the engage portions 3, 4. The lock member 5 is biased by a spring 7 connecting it to a chassis of the tape player in a direction to bring the lock portion at the distal end thereof into engagement with the engage portions 3. 4. 
     A head plate 10 is supported on the chassis for movement reciprocally in a direction perpendicular to the movement direction of the levers 1, 2, and is normally biased by a withdrawal spring 11 in a withdrawal (right in FIGS. 1-3) direction. The right end margin of the head plate 10 defines a push portion 9 which pushes the lever lock member 5 against the energy of the spring 7 when the head plate 10 withdraws. 
     The head plate 10 is resiliently connected to a shift plate 12 by a spring 13. The shift plate 12 has an engage hole 14 which movably receives a pull member 15 of a power plate so that the shift plate 12 together with the head plate 10 is pulled ahead (leftward in FIGS. 1-3) by the pull member 15 which is moved ahead by an intermittent cam which is not illustrated as is rotated merely on advance movement of the head plate. The shift plate 12 has at the left end thereof a tapered engage portion 16 engageable with a lock member 17 when the shift plate 12 is moved ahead (to the left in the drawings). The lock member 17 is movably inserted in a guide hole 18 formed in the chassis of the tape player, and is normally biased by a spring 19 in a direction for engagement with the shift plate 12. 
     The shift plate 12 is pivotably connected to the head plate 10 by engagement between an axle 21 and an elongated hole 20. A release link 30 for preventing rotation of the shift plate 12 is provided near the right end of the shift plate 12 pivotably about an axle 31, and is biased by a withdrawal spring 32 which has a smaller energy than the spring 11 so that one end of the release link 30 contacts the opposed margin of the shift plate 12. A second end 33 of the release link 30 opposite to the first end is releasably attracted by a lock plunger 40 to lockingly maintain the first end in slidable contact with the shift plate 12. 
     The lock plunger 40 is controlled by a control circuit not shown so that it is basically kept energized after a play mode instruction is entered but is temporarily deenergized in the inter-music detection mode when the head detects a non-signal portion between pieces of music on a tape. 
     As shown in FIG. 1, when a play-mode instruction is entered in the tape player, the plunger 40 is energized by activation of the motor, and attractively pulls the second end 33 of the release link 40. This attraction is facilitated by the clockwise biasing force of the spring 32. When the release link 30 is locked by the plunger 40, the first end of the link 30 prevents the shift plate 12 from rotation, so that the shift plate 12 pulled by the pull member 14 in the engage hole 15 simply moves linearly, slidably contacting the first end of the release link 30. The pull member 15 of the power plate is moved ahead linearly by the intermittent cam which is rotated when and after the motor starts rotating. The head plate 10 connected to the shift plate 12 is moved ahead together with same, and when it reaches its advance position, the lock member 17 of the chassis enters in the tapered engage portion 16 of the shift plate 12 with the energy of the spring 19. Therefore, the shift plate 12 and head plate 10 are locked there, and the play mode is established. The engage member 16, although tapered, never disengages from the lock member 17 so long as the shift plate 12 is prevented from rotation by the release link 30. 
     Referring to FIG. 2, when the FF or REW lever 1 or 2 is manually compressed in the play mode for inter-music detection, the pushed lever 1 or 2 is locked there by locking engagement between the engage portion 3 or 4 and the lock member 5 biased by the spring 7, and the FF or REW mode is established. At that time, a control portion 50 formed in the FF or REW lever is configured to compress an engage pin 51 formed on the head plate 10, the head plate 10 is forcibly pulled back to a position where the head slightly contacts a tape. The relative displacement produced thereby between the head plate 10 and the shift plate 12 is resiliently absorbed or adjusted by the spring 13. 
     When the head detects a non-signal portion between pieces of music on the tape, the plunger 40 is deenergized, and unlocks the release link 30. Therefore, the shift plate 12 loses the energy from the release link 30 and is allowed to rotate about the axle 21. As the result, the shift plate 12 which receives a withdrawal force from the head plate withdrawal spring 11 is rotated counterclockwise due to a moment produced at the tapered engage portion 16. Therefore, the shift plate 12 is unlocked from the lock member 17 and allowed to withdraw together with the head plate 10. 
     Referring to FIG. 3, when the head plate 10 withdraws, the push portion 9 at the right end thereof pushes the lock member 5 against the spring 7 to release the urging of engage portion 3 or 4 of the lever 1 or 2 from the lever lock member 5, and the lever 1 or 2 is allowed to return to its original position with the energy of the revival spring therefor. 
     After the lever 1 or 2 is released, the plunger 40 is energized again, and the mechanism takes the same configuration as on the aforegoing play-mode instruction. Therefore, the shift plate 12 and head plate 10 are allowed to advance similarly, and when the shift plate 12 is locked, the play mode is restored and maintained (see FIG. 1). 
     As described, the invention lock mechanism of a head plate and RR/REW levers uses a single plunger not only for locking the head plate at its advance position but also for locking the FF or REW lever at an inserted position. This arrangement reduces the number of plungers and control circuits or switches therefor, and contributes to a simplified construction of the tape player and a cost reduction of the lock mechanism.