GB2149184A

GB2149184A - Rewinding apparatus for a tape cassette

Info

Publication number: GB2149184A
Application number: GB08329078A
Authority: GB
Inventors: Chun Tsai Yeh
Original assignee: Individual
Current assignee: Individual
Priority date: 1983-11-01
Filing date: 1983-11-01
Publication date: 1985-06-05
Also published as: GB8329078D0

Abstract

A tape rewinding apparatus which is released in response to an increase of the tension difference between the tension side run (76) and the slack side run (77) of a transmission belt (7) which drives a pulley (6) on a rewinding spindle (4). The change of tension difference is sensed by one or more small pulley(s) which are arranged in the running path of the transmission belt (7) to increase the tension thereof. A driving motor rotates in such direction that the tension side run will be tightened while the slack side run will slip on the said small pulley upon the winding spindle being hindered from rotating, whereby straightening of the tension side run will initiate cassette holder (3) ejection and turn off the power supply to the motor. <IMAGE>

Description

SPECIFICATION Rewinding apparatus for a tape cassette This invention relates to an improved rewinding apparatus for tape cassettes, particularly video tape cassettes.

In order to make the magnetic head more durable, conventional video cassette recorders do not usually have a built-in apparatus for rewinding the tape. Instead, an independent rewinding apparatus is normally used to perform this function. While the independent rewinding apparatus is operating, the user has to watch and wait until the completion of the rewinding, and then eject the cassette manually. To avoid the inconvenience of such a procedure, some automatic ejection type rewinding apparatuses have appeared on the market. One of these has a built-in tape end detecting solenoid actuated by an electric signal to start the cassette ejection action, and an electronic control circuit for automatically cutting off the power supply.

According to the present invention there is provided a rewinding apparatus for a tape cassette, comprising a cassette holder mounted for movement between a rewinding position and a released position, a rewinding spindle driven by a transmission belt, a catch member for holding the cassette holder in said rewinding position, a release member movable to release said catch member, and tension sensing means engaging both the tension side run and the slack side run of said transmission belt and arranged, upon a predetermined increase in the difference in tension between said runs which results from completion of rewinding of the tape in operation, to be displaced by the belt to operate said catch release member to release said catch.

In one form of the invention said tension sensing means comprises a pivotally mounted actuating member having a pair of pulleys rotatably mounted thereon, said pulleys being aligned transversely to the direction of running of said transmission belt and being respectively driven by the tension side run and the slack side run thereof, the arrangement being such that, upon a said increase in the difference in tension between said runs, the tension side run will straigten sufficiently to displace said pulleys and said actuating member laterally to engage and displace said release member.

In another form of the invention said tension sensing means comprises a pivotally mounted actuating member having a pulley provided with axially spaced grooves rotatably mounted thereon, said tension side run and slack side run of said transmission belt passing around the respective grooves of said pulley on opposite sides thereof, the arrangement being such that, upon a said increase in the difference in tension between said runs, the tension side run will straighten sufficiently to displace said pulley and said actuating member laterally to engage and displace said release member.

Some embodiments of the invention will now be described by way of example and with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a first embodiment of a video cassette rewinding apparatus according to the invention, Figure 2 is a perspective view showing the relevant parts of a second embodiment of such an apparatus; and Figure 3 is a similar view showing a third embodiment.

Referring first to Fig. 1, a pair of opposed brackets 1 and 2 are mounted in a frame at parallel spacing from each other and a cassette holder 3, which has a slot (not shown) for receiving a cassette, is pivoted to the brackets 1 and 3 by pins 30. Beneath the holder 3 a connecting element 18 is pivoted to a crank arm 10 at its lower end and has a pin 19 at its upper end which serves as a catch member engaging in an apertured lug on the underside of the holder 3, to a hold the latter down in its closed position when a further pin, on the crank arm 10, is retained by a release member in the form of an arm 8 engaging thereon. When the holder 3 is raised by crank arm 10 the resilience of compression springs 15, 16 buffers such ejection action. A rewinding spindle 4 is driven by a transmission belt 7 through a pulley 6 secured to the bottom end of spindle 4.

Arm 8 is mounted above the pulley 6 in such manner that its end adjacent the crank arm 10 can be moved outwardly.

Tension sensing means comprises an actuating member in the form of a tongue 55 pivoted at one end to the winding spindle 4 and extending under the pulley 6 and outwardly thereof. A pair of small pulleys 53, 54 are rotatably mounted on the free end of the tongue member 55 and are driven by the tension side run 76 and the slack side run 77 of the transmission belt 7, from a motor which rotates counterclockwise.

When the tape comes to its end in operation, the rewinding spindle 4 is hindered from rotating, and at this moment the ongoing motion of the driving motor will cause slippage of the slack side run 77 of belt 7 on the pulley 54, and, at the same time, further tightening of the tension side run 76. Consequently the tension difference already existing between the two runs of the belt is abruptly augmented. Such further tightening of the tension side run 76 entails a tendency of the same to straighten, whereby the tension side run 76 will urge the pulley 53 towards the arm 8 and thereby push the latter to move a distance sufficient to disengage from the afor ementioned pin on the crank arm 10, thus causing the holder 3 to be raised and thereby breaking the circuit established in the apparatus.

In other embodiment of the invention, shown in Fig. 2, only one small pulley 50 is employed, by an adjustment of the belt arrangement. In this embodiment the tension side run 76 and the slack side run 77 of the transmission belt 7 are crossed over each other as shown, and the motor rotates clockwise, so that the tension side run 76 normally biases the small pulley 50 toward the arm 8 (not shown). When the tape reaches its end the slack side run 77 will slip on the small pulley 50 while the tension side run 76 will be further tightened and will straighten, thus moving the tongue member 55 to initiate the ejection of the cassette holder.

A further embodiment is shown in Fig. 3 wherein, in order to avoid the reversal of rotation direction of the motor which occurs in Fig. 2, the transmission belt 7 is crossed again between the motor and the pulley 50, the operation of the apparatus being otherwise the same.

It will thus be seen that the present invention, at least in its preferred and illustrate embodiments, provide a tape cassette rewinding apparatus with improved precision in operation, and with a simplified structure which leads to more economical manufacture.

Claims

1. A rewinding apparatus for a tape cassette, comprising a cassette holder mounted for movement between a rewinding spindle driven by a transmission belt, a catch member for holding the cassette holder in said rewinding position, a release member movable to release said catch member, and tension sensing means engaging both the tension side run and the slack side run of said transmission belt and arranged, upon a predetermined increase in the difference in tension between said runs which results from completion of rewinding of the tape in operation, to be displaced by the belt to operate said catch release member to release said catch.

2. Apparatus as claimed in claim 1, wherein said sensing means comprising a pivotally mounted actuating member having a pair of pulleys rotatably mounted thereon, said pulleys being aligned transversely to the direction of running of said transmission belt and being respectively driven by the tension side run and the slack side run thereof, the arrangement being such that, upon a said increase in the difference in tension between said runs, the tension side run will straighten sufficiently to displace said pulleys and said actuating member laterally to engage and displace said release member.

3. Apparatus as claimed in claim 1, wherein said sensing means comprises a pivotally mounted actuating member having a pulley provided with axially spaced grooves rotatably mounted thereon, said tension side run and slack side run of said transmission belt passing around the respective grooves of said pulley on opposite sides thereof, the arrangement being such that, upon a said increase in the difference in tension between said runs, the tension side run will straighten sufficiently to displace said pulley and said actuating member laterally to engage and displace said release member.

4. Apparatus as claimed in any of claims 1 to 3, wherein the said catch member is a pin extending transversely from a pivotally mounted crank arm, and the said release member is an arm engageable with another pin on the crank arm to hold the latter against pivotal movement in the releasing direction.

5. Rewinding apparatus for a tape cassette, substantially as hereinbefore described with reference to the accompanying drawings.