GB2262933A - Tape cassette cover lock - Google Patents

Abstract

A tape cassette has cover lock 98 pivotable on upright post 92 for selectively locking and unlocking pivotal cover 100. The lock 98 has a planar body with a lock-actuating lug 110 projecting through a first cassette aperture 88 and a cover-locking claw 112 extending through a second aperture 90. Claw 90 engages with cover recess 104. Leaf spring 116 is integrally molded with the cover lock 98 to bias the lock. The spring may be tapered, or replaced by a separate coil spring. <IMAGE>

Description

TAPE CASSETTE WITH AN IMPROVED FRONT COVER LOCKER The present invention relates to a tape cassette for use in video tape recorders and, more particularly, is directed to a tape cassette having an improved front cover locker which normally holds a front cover or lid of the cassette in a locked position against a pivotal movement and which allows, when the cassette is in use, the front cover to swing into an open position.

As shown in Fig. 1, the conventional tape cassette is provided with a cassette housing 10 of a box-like configuration and a front cover or lid 12 mounted on the housing 10 in a manner that it can swing about a pivot shaft 14 between a closed position as illustrated in Fig. 1 and an open position(not shown). When the tape cassette is not used or played, the front cover 12 is normally kept in the closed position by means of a cover locker 16 as set forth below in detail. When the tape cassette 10 is loaded into a video tape recorder, the cover locker 16 operates to unlock the front cover 12, thereby allowing the cover 12 to swing at a right angle toward the open position wherein a frontal stretch of the magnetic tape 18 becomes exposed.

Referring to Fig. 2, there is shown a typical example of prior art cover locking mechanism that has been extensively used in the tape cassette industry and is applicable to the tape cassette shown in Fig. 1. The cassette housing 10 is provided with a lower half part 20 having a side wall 22 through which a first and a second rectangular holes 24 and 26 are formed in an offset relationship to one another. In addition to the rectangular holes, there are provided in the lower half part 20 a pair of top grooves 28 and 30 that extend along a common axis parallel to the side wall 22. Over the top grooves 28 and 30, the cover locker 16 is hingedly placed so that it can be subjected to an angular movement about its pivot axis 32. The cover locker 16 includes a lug 34 that may project through the first hole 24, when the locker 16 is in its position.Adjacent to and in a parallel relationship with the lug 34, a claw 36 is provided which passes through the second hole 26 and then releasably engages with a recess 38 of the front cover 12. Normally, the locker 16 of the type described above is biased by means of a coil spring 40 toward the direction of locking the front cover 12. Unlocking of the cover 12 is effectuated by way of pushing the lug 34 of the cover locker 16.

U.S. Patent No. 4,485,988 to Kikuya et al. discloses a tape cassette that employs another type of locking device as illustrated in Fig. 3. The tape cassette includes a cassette housing 54 and a swingable cover 50 adapted to hide and hence protect a tape run 52 stretched along the front side of the tape cassette. In addition, the cassette housing 54 comprises bifurcated parallel side walls 56 having a pair of coaxial top grooves 58 formed thereacross and a cover locking member located on the top grooves 58 of the side walls 56 so as to restrain pivotal movement of the swingable cover 50.

The cover locking member is provided, at its front edge, with a vertical claw 60 that will so engage with a lug 62 of the swingable cover 50 as to allow the locking member to swing about its pivot axle 64 on a plane perpendicular to the tape run 52. A leaf spring 66 is utilized to urge or bias the locking member in the direction of having the swingable cover 50 locked against free rotation.

In such prior art cover locking devices as set forth above, the cover locker or locking member is simply laid on the top grooves of the lower cassette housing in an extremely unstable condition. As a result, during the course of transferring a semi-assembled tape cassette from station to station in an assembly line, the cover locker is hardly kept in position and, therefore, tends to displace out of the grooves, due to the mechanical vibration or physical shocks exerted on the cassette housing itself. This may result in a finished cassette of poor quality or even a misassembled or inoperable tape cassette, which would substantially reduce the yield of the cassette products.

Another disadvantage of the locking devices known in the art is that they need a separate and independent spring element capable of biasing the cover locker in the direction of locking the front cover against rotation. The task of manufacturing and assembling the separate spring element is highly laborious, costly and time-consuming, which in turn, increases the cost of producing the tape cassette products.

In accordance with the present invention, there is provided a tape cassette adapted to be, when'in use, loaded into a video tape recorder and the like, which comprises: a cassette housing containing therein a pair of tape reels interconnected by a length of frontal tape run extending along a front side of the cassette housing, said cassette housing including a upper and a lower half parts fitted together at their open edges, said lower half part provided with a side wall which has a first and a second apertures formed therethrough and a bottom wall which has an upright pole in the vicinity of the side wall;; a front cover pivotably carried by the cassette housing and swingable between a closed position and an open position for selectively hiding and exposing the frontal tape run, said front cover including a terminal flange having a recess on its inner surface, said recess being in an alignment with the second aperture of the side wall when the front cover assumes the closed position, a cover locker removably held by the upright pole of the bottom wall and pivotable between a first position in which the front cover is locked against a pivotal movement and a second position in which the front cover is unlocked and thus enabled to swing about the upright pole to the open position, said cover locker having a body of a substantially plate configuration, a lug projecting from the body through the first aperture and a claw extending from the body through the second aperture and then releasably engaging with the recess of the front cover; and means for biasing the cover locker toward the first position to get the front cover locked against pivotal movement Ideally, the biasing means comprises a leaf spring integrally molded with the front cover at the opposite side of the body from the lug and the claw. The leaf spring extends slantly at an angle with respect to the body of the cover locker.

An advantage of the present invention is that the cover locker of the tape cassette can be securely kept in its originally assembled position without any unwanted displacement when a tape cassette is transferred from one station to another in an assembly line.

A further advantage of the present invention is that it obviates the need to employ a separate biasing spring for the cover locker by using instead a monolithic leaf spring integrally moulded with the cover locker.

The present invention will be illustrated further, by way of example only, with reference to the accompanying drawings. In the drawings: Fig. 1 shows a conventional known tape cassette with the front cover thereof in a closed position; Fig. 2 is an exploded perspective view illustrating one example of the front cover locking device employed in the prior art tape cassette; Fig. 3 is a view showing another example of the front cover locking device for use in the prior art tape cassette; Fig. 4 is an exploded, partially cut away, perspective view of the tape cassette embodying the present invention; Fig. 5 is a perspective view of the cover locker showing the leaf spring integrally molded with the cover locker; and Fig. 6 illustrates the cover locker pivotably retained by an upright post of the lower cassette housing, with the front cover locked in its closed position.

In the drawings, like reference numerals refer to like parts.

A preferred embodiment of the present invention will now be described in detail with reference to Figs. 4 to 6.

Referring to Fig. 4, a tape cassette embodying the invention is shown as an exploded, partially cut away, perspective view to highlight the novel features of the inventive cover locking device.

As shown, the tape cassette comprises a cassette housing of a boxlike configuration, generally designated at 70, which in turn, is divided into a upper and a lower half parts 72 and 74 combined or coupled together at their open edges. It is known that the cassette housing 70 contains therein a pair of spaced tape reels 76(shown by phantom lines) which are interconnected to one another by a length of tape run extending along a frontal side of the cassette housing 70.

The lower half part 74 includes a front wall 78, a bottom wall 80 and a side wall 82 that meets at a corner with the front wall 78. Preferably, the side wall 82 consists of a first extension 84 and a second extension 86 somewhat recessed toward the center of the lower half part 74 from a plane on which the first extension 84 lies. This ensures that the first extension 84 is flush with a terminal flange of a front cover set forth hereinbelow. The second extension 86 of the side wall 82 that extends between the front wall 78 and the first extension 84 has a first and a second apertures 88 and 90 formed therethrough in a-side-by-side relationship with each other.

As can be seen from Figs. 4 and 6, the bottom wall 80 includes an upright pole or post 92, a barrier block 94 and a partition 96, each extending vertically upwardly from the bottom wall 80. The upright post 92 is located in the vicinity of the side wall 82 for pivotably holding a cover locker 98 in place. As best shown is Fig.

6, the barrier block 94 comes into abutment with the cover locker 98 and thereby hampers clockwise pivotal movement thereof. Furthermore, the partition 96 cooperates with the front wall 78 and the second extension 86 of the side wall 82 to define a compartment where the cover locker 98 is accommodated in a pivotable manner. If desired, either one of the barrier block 94 and the partition 96 may be omitted in its entirety, so long as the pivotal movement of the cover locker 98 in the clockwise direction is restrainable.

It is highly conventional that the front cover 100 is carried by the cassette housing 70 and swingable between a closed position and an open position for selectively hiding and exposing the tape run stretched along the frontal side of the cassette housing 70. Above all, the front cover 100 includes a terminal flange 102 which becomes flush with the first extension 84 of the side wall 82, when the front cover 100 is kept in the closed position.

On the inner surface of the terminal flange 102, a recess 104 is provided which will be in an exact alignment with the second aperture 90 of the side wall 82.

Referring to Figs. 4 to 6, the cover locker 98 consists of a tubular hub 106 and a body 108 of a substantially plate-like shape extending from the hub 106 toward its free end. The cover locker 98 further includes a lug 110 projecting from one side of the body 108 through the first aperture 88 of the side wall 82 and a claw 112 extending in parallel with the lug 110 through the second aperture 90 of the side wall 82 to releasably engage with the recess 104 of the front cover 100. The tubular hub 106 is inserted around the upright post 92 in such a manner that it can be removably held by the post 92 and becomes pivotable between a first position in which the front cover 100 is locked against any pivotal movement and a second position in which the front cover 100 is unlocked and thus allowed to swing about the post 92 to the open position.At the top of the locker body 108, there is provided a cutout 114 that functions as a light passageway through which a light beam emitted from a photosensor (not shown) is passed in a manner known in the art.

As best illustrated in Figs. 5 and 6, the cover locker 98, in a preferred embodiment, is provided with, at the opposite side of the body 108 from the lug 110 and the claw 112, a monolithic leaf spring 116 integrally molded with the cover locker 98. The leaf spring 116 extends slantly at an angle with respect to the body 108 and is invariably brought into contact with the barrier block 94 of the cassette housing 70, as clearly shown in Fig. 6, to urge or bias the cover locker 98 toward the first locking position.

In order to maximize the elasticity of the leaf spring 116, it is desirable that the leaf spring 116 should be tapered from a proximal end to a distal end so that the proximal end can have a greater cross-sectional area than the distal end. Alternatively, the monolithic leaf spring 116 may be substituted by a conventional separate coil spring, thereby obviating any need to change the basic design of the cover locker.

In operation, although the cover locker 98 is normally kept in the first locking position as shown in Fig. 6, it will be subjected to a pivotal movement in the clockwise direction against the spring force, as the lug 110 is being pushed in the direction of arrow 118 either by the action of a release lever or manually.

Once the cover locker 98 is pivoted to the second position, the claw 112 will disengage with the recess 104 of the front cover 102, thereby unlocking the front cover 102. Under that condition, the front cover 102 is enabled to swing to the open position wherein the tape run extending along the frontal edge of the cassette housing 70 will be exposed. In contrast, if the lug 110 is released from pressure with the front cover 100 in the closed position, the cover locker will return to the first locking position by the restoration force of the leaf spring 116 so that the front cover 100 may be locked against any pivotal movement.

Claims (6)

CLAIMS:

1. A tape cassette adapted to be, when in use, loaded into a video tape recorder and the like, which comprises: a cassette housing containing therein a pair of tape reels interconnected by a length of frontal tape run extending along an front side of the cassette housing, said cassette housing including a upper and a lower half parts fitted together at their open edges, said lower half part provided with a side wall which has a first and a second apertures formed therethrough and a bottom wall which has an upright pole in the vicinity of the side wall;; a front cover pivotably carried by the cassette housing and swingable between a closed position and an open position for selectively hiding and exposing the frontal tape run, said front cover including a terminal flange having a recess on its inner surface, said recess being in an alignment with the second aperture of the side wall when the front cover assumes the closed position;; a cover locker removably held by the upright pole and pivotable between a first position in which the front cover is locked against a pivotal movement thereof and a second position in which the front cover is unlocked and allowed to swing about the upright pole to the open position, said cover locker including a body of a substantially plate configuration, a lug projecting from the body through the first aperture and a claw extending from the body through the second aperture and then releasably engaging with the recess of the front cover; and means for biasing the cover locker toward the first position to get the front cover locked against a pivotal movement thereof.

2. A tape cassette as claimed in claim 1, wherein the biasing means comprises a leaf spring integrally molded with the cover locker at the opposite side of the body from the lug and the claw.

3. A tape cassette as claimed in claim 2, wherein the leaf spring is inclined at an angle to the body of the cover locker.

4. A tape cassette as claimed in claim 2 or 3, wherein the leaf spring is tapered from its proximal end toward its distend, with the proximal end having a greater cross-sectional area than the distal end.

5. A tape cassette as claimed in claim 4, wherein said bottom wall is further provided with an upwardly extending barrier block for abutment against the distal end of the leaf spring.

6. A tape cassette according to claim 1, substantially as hereinbefore described with reference to, and as illustrated in, Figures 4, 5 and 6 of the accompanying drawings.