This invention relates to tape cassettes and, more particularly, to a reel leaf spring of a video tape cassette cover for rotatably supporting the hubs of tape reels in the tape cassette, and a removable dust door which cooperates therewith.
A conventional video tape cassette includes a base and a cover, each made of plastic. The assembled base and cover accommodate a pair of tape reels, each including a hub for winding magnetic recording tape therearound.
The cassette also usually includes a separate reel leaf spring, i.e., a spring stamped from a flat piece of metal or alloy, such that arms are bent to extend from both sides of a central, flat portion of the spring, as described in Assignee's U.S. Pat. No. 4,662,579, entitled "Coined Reel Leaf Spring for a Video Tape Cassette." The central, flat portion of the reel leaf spring includes holes to receive projections formed on a central planar area of the underside of the cover. The free ends of the projections are swedged or post formed to extend around the holes and permanently hold the leaf spring relative to the cover.
With the arrangement described above, when the cover including the reel leaf spring is assembled with the base, both of the free ends of the arms of the spring contact the hubs of the respective tape reels and bias the tape reels downwardly, so that the tape reels are rotatably retained in position with adequate pressure to interface a tape player/recorder. That is, when the cassette is placed in the tape player/recorder, spindles of the tape player/recorder enter the hubs and lift the reels against the force of the spring. When the cassette is not in the tape player/recorder, the spring pushes the reels against the base and the reels are prevented from rotating by a reel lock device well known in the art. Alternatively, teeth on the cassette base could cooperate with teeth on the reel to lock the reels, as described in Assignee's co-pending U.S. patent application Ser. No. 07/471,648, entitled "Static Tape Cassette Reel Lock," now U.S. Pat. No. 5,052,632.
Assembly of this spring is relatively labor intensive. That is, the springs must be stamped and bent, the holes must be accurately formed, the corresponding projections must be molded on the cassette cover, the spring must be mounted so that the holes properly receive the projections, and the projections must be post formed. All of these steps, of course, raise the cost of the entire cassette.
Further, after positioning the spring on the cover, but before permanent connection, it is possible that the spring could be dislocated relative to the projections while progressing in the assembly line.
Moreover, with cassettes, as with all plastic consumer goods, a need exists to find ways to re-cycle the products instead of merely depositing them in land fills. Of course, the more difficult and expensive it is to separate different materials such as metal and plastic, in this case the spring from the cassette cover, the less incentive there is to recycle.
The Assignee's copending U.S. patent application Ser. No. 458,428, entitled "Reel Leaf Spring/Cassette Cover Combinations and Methods for Assembly" now U.S. Pat. No. 4,986,491, describes a reel leaf spring which is removably cam fit or press fit between projections or ramps formed on the cassette cover. This structure facilitates assembly and re-cycling by making it easier to install and remove the metal reel leaf spring relative to the cassette cover. Further, Assignee's copending application Ser. No. 676,380 entitled "Wire Reel Leaf Spring/Cassette Cover Combination and Methods for Assembly" now U.S. Pat. No. 5,199,661, describes a metal wire reel leaf spring which also shares these attributes.
However, the reel leaf springs discussed above still are not the most cost-efficient, nor do they lend themselves to the easiest fabrication and re-cycling.
A conventional cassette further includes a pivotable, spring biased dust door which, when closed, protects the tape from dust, contact, etc. An example of such a dust door is described in Assignee's U.S. Pat. No. 4,533,093, entitled "Tape Cassette Dust Door Spring Assembly and Method for Assembling Same." When the door is opened, usually automatically by a tape player/recorder when the cassette is placed therein, the magnetic head of the player/recorder can gain access to the tape.
Incorporating such a dust door in a cassette requires molding of the door, formation of a spring, installation of the spring on the dust door, loading of the spring against the cassette, producing, installing and loading a dust door latch and related spring, and biasly capturing the dust door between the base and cover as the base and cover are mated during assembly. This number of steps is not very cost-efficient. Further, there is always the chance that the parts, such as the dust door spring, could become misaligned during manufacture, shipping, handling or use, and fail to properly operate.
Finally, none of the prior art dust doors in any way cooperates with the reel spring to improve the resilient life thereof.
Assignee's co-pending U.S. application Ser. No. 610,585, entitled "REMOVABLE DUST DOOR INCORPORATING TAPE REEL LOCK," now abandoned, describes a removable dust door, but same also does not cooperate with a reel spring.
Thus, the dust doors discussed above still are not the most cost-efficient, nor do they lend themselves to the easiest fabrication and re-cycling and they fail to combine in any way with the reel spring.