1. Technical Field
The present invention relates to a magnetic tape device, having a simple and inexpensive structure, that can hold a tape cassette at a predetermined location on a moving table without unexpectedly wobbling.
2. Related Art
An example conventional technique for a magnetic tape device, disclosed in the Unexamined Japanese Patent Application Publication No. Sho58-141461, will be described while referring to FIGS. 10 to 12. An upright pair of guide plates 3a and 3b are provided in parallel on a chassis 2 in a housing 1, and multiple guide pins 5 project from either side of a tape cassette moving table 4, located between the guide plates 3a and 3b. When these guide pins 5 are movably inserted into multiple L-shaped guide holes 6 that penetrate the guide plates 3a and 3b, the moving table 4 can move forward and backward, in directions a and b, between a cassette insertion position A and a cassette mounting position B. Then, rotary levers 8 are fitted over a shaft 7 with the guide plates 3a and 3b so that the levers 8 are pivotable forward and backward, in directions c and d, and engage the front guide pins 5. A worm gear 10 is disposed in the center of the outer face of a rotary cam 9 that is rotatably positioned on the reverse face of the chassis 2, and a worm gear 11, which is driven by a driving source (not shown), engages the worm gear 10. A bevel gear 12 is formed on the upper, outer face of the rotary cam 9, and a gear 13 is formed at the base end of the rotary lever 8, which is coupled with the gear 13 by a clutch gear mechanism 14. A top board 15 bridges the distance between the guide plates 3a and 3b. 
In FIG. 10, reference numeral 17 denotes movable tape guide posts, along which a magnetic tape t is pulled out of a tape cassette T and passes around a head cylinder 18. Reference numeral 19 denotes a full-width erasing head; 20, a speech erasing head; 21, a speech control head; 22, fixed tape guide posts; 23, back tension posts; 24, a capstan; and 25, a pinch roller.
With this configuration, as is indicated by a solid line in FIG. 12, while the moving table 4 is held in the cassette insertion position A, the tape cassette T is loaded into a tape cassette insertion slot 1a of the housing 1. Then, since the clutch of the gear mechanism 14 is disengaged, as the tape cassette T is inserted toward the movable table 4, the movable table 4 is pushed slightly to the rear, in direction b. Based on a detection signal from a detector (not shown) that detects the insertion, the clutch of the gear mechanism 14 is engaged by the driving source through the worm gears 11 and 10 and the rotary cam 9, and the rotary cam 9 and the rotary lever 8 interact via the gear mechanism 14. Thereafter, when the rotary lever 8 is pivoted to the rear, in direction d, by the driving source, the moving table 4 is displaced horizontally along the guide holes 6 to the rear, in direction b, descending vertically until the tape cassette T is mounted in the cassette mounting position B (see imaginary line in FIG. 12). Then, the magnetic tape t is extracted from the tape cassette T (see imaginary line in FIG. 10), and the reproduction and other operations are performed.
Further, when an eject button (not shown) is depressed, based on an ejection signal that is emitted, the rotary lever 8 is pivoted forward, in direction c, by the driving force transmitted by the gear mechanism 14. The moving table 4 at the cassette mounting position B is raised vertically along the guide holes 6 and is moved forward, in direction a, to the cassette insertion position A, and the tape cassette T is ejected (see solid line in FIG. 12).
As is shown in FIGS. 10 to 12, the moving table 4 includes a bottom plate 4a and a pair of side plates 4b, which are secured to the side edges of the bottom plate 4a and from the side walls of which the guide pins 5 project. A pair of leaf springs 4d are securely attached to projections 4c that project inward, toward the center of the moving table 4, from the upper edges of the side plates 4b. The tape cassette T is held at a predetermined location on the moving table 4 by the urging force exerted by the leaf springs 4d, while the distal ends of the leaf springs 4d contact the upper face of the tape cassette T seated on the moving table 4. Thus, unexpected wobbling of the tape cassette is encountered upon its insertion and ejection.
With the above arrangement, since the leaf springs 4d are employed to hold the tape cassette T in a predetermined position in the moving table 4, the number of parts is increased due to these leaf springs 4d, and the structure is complicated. In addition, a great deal of labor and time are required to fix the leaf springs 4d to the projections 4c, so that the manufacturing method is demanding and the manufacturing expenses are increased.
To resolve the shortcomings, it is one objective of the present invention to provide a magnetic tape device, having a simple and inexpensive structure, that can hold a tape cassette in a predetermined position in a moving table without the tape cassette wobbling unexpectedly.
To achieve this objective, according to a first aspect of the invention, a magnetic tape device is provided
wherein a moving table includes a bottom plate and a pair of side plates securely fixed to side edges of the bottom plate, and is positioned so as to move forward and backward between a cassette insertion position and a cassette mounting position located between a pair of guide plates;
wherein a tape cassette is inserted into and held in the moving table, located at the cassette insertion position, and the moving table is moved backward based on a detection signal produced upon the insertion of tape cassette, so that the tape cassette, in the moving table, is mounted at the cassette mounting position;
wherein a pair of integrally formed float prevention members, project inward from the upper ends of the side plates, toward the center of the moving table, and engage the upper edge of the tape cassette that is held in the moving table;
wherein a pair of projecting gripping members contact both side faces of the tape cassette inserted into and held in the moving table;
wherein the gripping members have a substantially trapezoid shape in plan view, the gripping members extending forward and backward along the side plates and inclining at both longitudinal ends toward the center of the moving table;
wherein the bottom plate, made of flexible steel, is bent in the center to form a substantially longitudinal reinforcing projection extending upward toward the moving table; and
wherein, when the side faces of the tape cassette inserted into the moving table are brought into contact with the gripping members, the bottom plate is flexed, and the urging force thus generated presses the gripping members flexibly against the side faces of the tape cassette.
According to this arrangement, the integrally formed float prevention members and gripping members are projected substantially at right angles at the upper ends of the side plates of the moving table. Therefore, when a tape cassette is inserted into the moving table, the float prevention members and the gripping members are brought into contact with the upper edge corners of the side faces of the tape cassette, so that the tape cassette can be securely held in a predetermined position in the moving table.
Further, the bottom plate is formed of flexible steel, and the reinforcement projection is formed by bending the center portion of the bottom plate. With this arrangement, an urging force exerting a predetermined pressure is generated by pushing the tape cassette between the gripping members, thereby flexing the bottom plate and forcing the gripping members flexibly against the side faces of the tape cassette, holding the tape cassette in the moving table so that it will not wobble unexpectedly.
Further, when the inclined end faces of the trapezoidal shaped gripping members are used as guide faces, the tape cassette can be smoothly inserted into the moving table. Further, since the inner side faces of the gripping members can contact both side faces of the tape cassette, the tape cassette can be stably held in the moving table.
Since an integrally formed pair of gripping members are projected from the inner side faces of the side plates, the number of parts is smaller than in the conventional case, wherein leaf springs are used, and the structure is simpler. When the gripping members and the floating prevention members, as well as the side plates, are formed of a synthetic resin, the manufacturing costs can be reduced.
According to a second aspect of the invention, in the magnetic tape device of the first aspect, the heights of the gripping members are set to be in a range from one to three times the thicknesses thereof.
With this arrangement, if the heights of the gripping members are less than the thicknesses of the members, the gripping members will be too small to hold a tape cassette. And if the heights of the griping members exceed three times the thicknesses of the members, the gripping members will be too large, so that the directional resistance of the members will be excessive, the force required to insert a tape cassette between the griping members will be comparatively large and usability will be deteriorated. Therefore, when the heights of the gripping members are set to be in a range from one to three times the thicknesses of the members, inserting a tape cassette will be easy, requiring the application of only a comparatively small insertion force, and usability will be superior. As an added dividend, the griping members will hold the tape cassette securely.
According to a third aspect of the invention, in the magnetic tape device of the first or the second aspect, the widths set, in the longitudinal direction, for the inner side faces of the gripping members are two to ten times the thicknesses of the members, and preferably are four to eight times the thicknesses.
With this arrangement, if the widths, in the longitudinal direction, of the inner side faces of the griping members are less than twice the thicknesses of the members, the widths of the gripping members will be too small to securely hold a tape cassette. And if the widths, in the longitudinal direction, of the inner side faces of the gripping members exceed ten times the thicknesses of the members, the gripping members will be too wide and the friction resistance of the griping member will be increased, the force required to insert a tape cassette between the gripping members will be comparatively large and usability will be deteriorated. Therefore, when the widths set, in the longitudinal direction, for the inner side faces of the gripping members are two to ten times the thicknesses of the gripping members, preferably four to eight times the thicknesses, inserting a tape cassette between the gripping members will be easy, requiring the application of only a comparatively small insertion force. And as an added dividend, the inner faces of the gripping members will hold the tape cassette securely.
According to a fourth aspect of the invention, a magnetic tape device is provided
wherein a moving table, which includes a bottom plate and a pair of side plates securely fixed to both side edges of the bottom plate, is located so as to move forward and backward between a cassette insertion position and a cassette mounting position that are set up between the guide plates;
wherein a tape cassette is inserted into the moving table that is held at the cassette insertion position, and the moving table is moved backward based on a detection signal emitted by the insertion, so that the tape cassette inserted into the moving table is mounted at the cassette mounting position; and
Wherein a pair of integrally formed gripping members are projected from the inner side faces of the side plates and contact both side faces of the tape cassette inserted into the moving table.
With this arrangement, when a tape cassette is inserted into the moving table held at the cassette insertion position, the gripping members projected together from the side plates of the moving table are brought into contact with the side faces of the tape cassette. Thus, the tape cassette can be precisely held at a predetermined position in the moving table to prevent the tape cassette from wobbling unexpectedly when inserted and ejected.
Since the integrally formed gripping members are projected from the inner side faces of the side plates, the number of parts that is required is smaller than in the conventional case wherein leaf springs are used, and the structure can be simplified. Further, when the gripping members and the side plates are mass-produced and integrally formed of a synthetic resin, the manufacturing expenses can be reduced.
According to a fifth aspect, in the magnetic tape device of the fourth aspect, an integrally formed pair of floating prevention members are projected from the upper ends of the side plates toward the center of the moving table, and engage the upper edge of the tape cassette inserted into the moving table.
With this arrangement, when the tape cassette is held by the gripping members, the pair of float prevention members can be employed to prevent the tape cassette from floating. Further, since the float prevention members, together with the side plates, and the gripping members are mass-produced using a synthetic resin, the manufacturing expenses can be reduced.
According to a sixth aspect of the invention, in the magnetic tape device of the fifth aspect, the gripping members, at corner portions, are projected together between the floating prevention members and the side plates.
With the arrangement, the integrally formed float prevention members and gripping members are projected, substantially at right angles, from the upper ends of the side plates. Thus, when a tape cassette is inserted into the moving table, the float prevention members and the gripping members are brought into contact with the upper edge corners of the side faces of the tape cassette, so that the tape cassette in the moving table can be securely held at a predetermined position.
According to a seventh aspect, in the magnetic tape device of one of the fourth to sixth aspects, the bottom plate is flexible, and when the tape cassette is inserted between the gripping members, pressure applied through the side plates flexes the bottom plate.
With this arrangement, the bottom plate is flexed by the insertion of a tape cassette between the gripping members, which generates an urging force. Through the application of the urging force, the gripping members are flexibly brought into contact with the side faces of the tape cassette, so that the tape cassette can be held in the moving table without wobbling.
According to an eighth aspect of the invention, in the magnetic tape device of the seventh aspect, the bottom plate is formed of flexible steel, and a reinforcing projection is formed inward, along to the moving table, by bending the steel plate, almost longitudinally, at the center.
With this arrangement, the bottom plate is formed of flexible steel, and the reinforcement projection is formed by bending the center portion of the bottom plate. When an urging force, exerting a predetermined pressure, is generated by pushing the tape cassette between the gripping members and bending the bottom plate, and when the urging force brings the gripping members into flexible contact with the side faces of the tape cassette, the tape cassette can be held in the moving table without wobbling unexpectedly.
According to a ninth aspect of the invention, in the magnetic tape device of one of the fourth to eighth aspects, the gripping members, in plan view, have a trapezoidal shape, and extend forward and backward along the side plates, from the longitudinal ends of the gripping members to the center of the moving table.
With this arrangement, a tape cassette can be smoothly inserted into the moving table along the inclined end faces of trapezoidal shaped gripping members, which serve as guide faces. Further, when the inner side faces of the gripping members are brought into contact with the side faces of the tape cassette, the tape cassette can be stably held in the moving table.
According to a tenth aspect of the invention, in the magnetic tape device of the ninth aspect, the heights of gripping members ranges from one to three times the thicknesses of the members.
With this arrangement, if the heights of gripping members are less than one times the thicknesses of the members, the gripping members are too small to hold a tape cassette. And if the heights of the gripping members exceed three times the thicknesses of the members, the gripping members are too large, and the friction resistance of the members is excessive. Thus, the force required to insert the tape cassette between the gripping members is comparatively large, and the usability is deteriorated. Therefore, when the heights set for the gripping members are one to three times the thicknesses of the members, inserting a tape cassette between the gripping members is easy, the force required to insert the tape cassette is comparatively small, and the usability is improved. As an added dividend, the gripping members can securely hold the tape cassette.
According to an eleventh aspect of the invention, in the magnetic tape device of the ninth or tenth aspect, the widths set, in the longitudinal direction, of the inner side faces of the gripping members is two to ten times the thicknesses of the members, and preferably, is four to eight times the thicknesses.
With this arrangement, when the widths, in the longitudinal direction, of the inner side faces of the gripping members is less than two times the thickness of the members, the widths of the gripping members are too small to hold a tape cassette. When the widths, in the longitudinal direction, of the inner side faces of the gripping members exceed ten times the thicknesses of the members, the gripping members are too large, and the friction resistance of the members is increased. Thus, the force required to insert a tape cassette between the gripping members is comparatively large, and the usability is deteriorated. Therefore, when the widths set for the inner side faces of the gripping members are two to ten times the thicknesses of the members, preferably, four to eight times the thicknesses, inserting a tape cassette between the gripping members is easy, the force required to insert the cassette between the gripping members is comparatively small, and the usability is improved. As an added dividend, the inner side faces of the gripping members can hold a tape cassette securely.