Tape cassette

Abstract: A tape cassette including a cassette case; a lid openably provided to the cassette case; a tape disposed in the cassette case; a component disposed to either the lid or the cassette case; and clasps for detachably maintaining the component to the lid or the cassette case.

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape cassette with a replaceable tape. 2. Description of the Related Art Tape cassettes are used in label printers and other devices. The tape cassettes used in label printers are provided with a tape from which labels are produced; various components, such as rollers for transporting the tape; and a cassette case for housing the tape and the various components. When producing labels uses up the tape housed in the cassette case, the old tape cassette is removed from the label printer and disposed of. Then another tape cassette with an unused tape is mounted into the label printer so that further labels can be produced. However, disposing of the tape cassette in this way wastes natural resources and generates trash. Also, replacing the entire tape cassette each time the tape runs out is expensive and increases running costs of the tape printer. SUMMARY OF THE INVENTION The present inventors invented a tape cassette that has an openable lid that can be attached to the cassette case. The tape housed in the cassette case can therefore be replaced by opening the lid. This makes the cassette case reusable. This tape cassette also includes components such as rollers rotatably disposed at predetermined positions in the cassette case. When the lid is opened to replace a used up tape with a new one, the roller can fall out of the cassette case and get covered with dirt and dust. EP-A-0 036 308 describes a tape cassette according to the generic portion of claim 1. In the cassette case a spring is provided engaging into a groove formed on the peripheral surface of the roller. DE-A-34 06 803 discloses a tape cassette being open at one side. Therefore, rollers in the tape cassette have to be fixed. The tape cassette comprises holes wherein the rollers having protrusions are inserted by reducing the diameter of the rollers. It is an object of the present invention to provide a tape cassette wherein rollers cannot fall out of the case or be lost even when the lid of the cassette case is opened to replace e.g. a used tape with a new one, wherein a simplified structure should be attempted. This object is solved by a tape cassette with the features of claim 1. Preferred developments of the tape cassette are given in the sub-claims. BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the invention will become more apparent from reading the following description of the embodiments taken in connection with the accompanying drawings in which: Fig. 1 is a perspective view showing a tape cassette, according to a first embodiment of the present invention, with a cassette lid removed; Fig. 2 is a plan view showing the tape cassette of Fig. 1 with a portion of the cassette lid removed; Fig. 3 is a magnified view of the cassette case of the first embodiment showing details of a roller and the area surrounding the roller; Fig. 4 is magnified view showing details of a roller and the area surrounding the roller according to a second embodiment; Fig. 5 is magnified view showing details of a roller and the area surrounding the roller according to a third embodiment; Fig. 6 is magnified view showing details of a roller and the area surrounding the roller according to a fourth embodiment; Fig. 7a is magnified view showing details of a roller and the area surrounding the roller according to a fifth embodiment; Fig. 7b is an overhead view of the roller of the fifth embodiment; and Fig. 8 is magnified view showing details of a roller and the area surrounding the roller according to another example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A tape cassette according to a preferred embodiment of the present invention will be described while referring to the accompanying drawings wherein like parts and components are designated by the same reference numerals to avoid duplicating description. First, an explanation of the structure of a tape cassette 1 of the present embodiment will be provided while referring to Figs. 1 through 3. The tape cassette 1 is for use loaded in a cassette mounting area (not shown in the drawings) of a label printer (not shown in the drawings) for producing tape-shaped labels. The configuration of the cassette mounting area in the label printer is well known and so its detailed description will be omitted here. The tape cassette 1 mainly includes a replaceable tape unit 10; a cassette case 11; a cassette lid 12; and a tape feed roller 21 for transporting a tape of the replaceable tape unit 10. The tape cassette 1 of the present embodiment which can be used many times by merely replacing the tape housed therein. Directional expressions used in the following explanation, such as "left," "right," "front," and "rear," describe positions of various parts and components when the tape cassette is the orientation in which it is used. Specifically, the expressions "upper" and "lower" refer to areas near the cassette lid 12 and the floor of the cassette case 11 respectively. The replaceable tape unit 10 is detachably disposed in the cassette case 11 and includes a tape spool 2; a print tape 3 made from thermal paper wound around the periphery of the tape spool 2; and upper and lower film sheets 4 adhered to upper and lower edges respectively of the print tape 3. Only the upper side film sheet 4 is shown in Fig. 1. The cassette case 11 is made from a substantially rectangular case with the upper side open. A pair of engagement holes 13 are opened in left and right sides (as viewed in Fig. 2) of the rear wall 11A of the cassette case 11. The engagement holes 13 are for engaging with engagement protrusions 30 formed to the cassette lid 12 (to be described later). A pair of protrusion portions 14 are formed on the right side (as viewed in Fig. 2) of the front wall 11B of the cassette case 11. The protrusion portions 14 form therebetween an engagement groove 15 into which a resilient engagement portion 34 provided to the cassette lid 12 (to be described later) engages. Further, a tape guide member 16 is formed to the cassette case 11 in continuation with the left side of the front wall 11B. A thermal head guide member 17 is provided to the rear of the tape guide member 16. The thermal head guide member 17 is formed with a rectangular opening 18 at a position corresponding to a thermal head (not shown in the drawings) disposed in the cassette mounting area. The thermal head is fitted in the rectangular opening 18 of the thermal head guide member 17 when the tape cassette 1 is loaded into the label printer. Also, an engagement slit 19 is opened in the rear wall of the rectangular opening 18. An engagement member 35 formed in the cassette lid 12 (to be described later) engages in the engagement slit 19 from the rear side of the rear wall of the rectangular opening 18. The tape feed roller 21 is rotatably disposed between the left wall of the cassette case 11 and the thermal head guide member 17. The tape feed roller 21 has a roller drive shaft 20 centered on its axis of rotation. A tape feed motor (not shown in the drawings) provided to the floor of the cassette mounting area. The roller drive shaft 20 is structured to engage with the upwardly protruding drive shaft of the tape feed motor when the tape cassette 1 is loaded in the label printer. Rotation of the tape feed motor drives the roller drive shaft 20. The tape feed roller 21 has a substantially cylindrical shape as shown in Figs. 2 and 3. A cylindrical flange portion 21A having a diameter larger than the diameter of the tape feed roller 21 is provided to the lower portion of the tape feed roller 21. On the other hand, two slightly hooked clasps 5 and 6 serving as a maintaining means are provided to the floor of the cassette case 11 adjacent to the position where the tape feed roller 21 is disposed. The clasp 5 of the two clasps is disposed to the right of the tape feed roller 21 as viewed in Fig. 3 and the other clasp 5 is disposed on the opposite side of the tape feed roller 21 as viewed in Fig. 3. It should be noted that rotation of the tape feed roller 21 for normal printing transports the print tape 3 from right to left as viewed in Fig. 3. Further, the clasps 5 and 6 are disposed so that faces 5A and 6A respectively thereof confront the tape feed roller 21. As shown in Fig. 2, the confronting faces 5A and 6A are formed in a curved shape that substantially follows the curve at the periphery of the tape feed roller 21. The two clasps 5 and 6 are integrally formed to the floor of the cassette case 11 from a flexible compound resin. While the tape feed roller 21 is mounted in the cassette case 11, the two clasps 5 and 6 are in engagement with the flange portion 21A of the tape feed roller 21. Further, the confronting surfaces 5A and 6A of the clasps 5 and 6 respectively confront the peripheral surface of the tape feed roller 21. As a result, the tape feed roller 21 is rotatably and detachably maintained in the cassette case 11 at a certain desirable position and posture even when the lid is opened. A tape spool housing area 42 for housing the replaceable tape unit 10 configured as described above is provided at the left rear of the cassette case 11. The replaceable tape unit 10 is housed in the tape spool housing area 42 so as to be rotatable about its axis of rotation. Tape guides 22, 23, 24, and 25 are provided with an upright posture to the floor of the cassette case 11. The tape guides 22, 23, 24, and 25 are for guiding the print tape 3 from the replaceable tape unit 10 to the thermal head guide member 17. The print tape 3 drawn from the tape spool 2 of the replaceable tape unit 10 is smoothly transported via the tape guides 22, 23, 24, and 25 to the thermal head positioned in the rectangular opening 18. A drive shaft 26 is provided with an upright posture to the floor of the cassette housing area 42 near the tape guide 23. The drive shaft 26 is used as the take-up shaft of a thermal ink ribbon housed in another type of tape cassette. Because the drive shaft 26 does not contribute to feed operations of the print tape 3, which is a heat sensitive paper, in the tape cassette 1 of the present embodiment, a tape spool 27 to reduce noise produced by the rotation of the drive shaft 26 is provided engaged with the drive shaft 26. A tape discharge area 28 is provided in the cassette case 11 near the tape feed roller 21. The tape discharge area 28 is formed from a slit-shaped gap formed in the cassette case 11 between an edge of the front left of the cassette case 11 and a guide member 29 that extends from the front left of the cassette case 11. Print tape 3 drawn from the tape spool 2 is guided to the thermal head by the tape guides 22, 23, 24, and 25. Characters and the like are printed on the print tape 3 by heat selectively generated at the print surface of the thermal head changing the color of the print tape 3. The print tape 3 with characters printed thereon is then discharged out of the tape cassette 1 through the tape discharge area 28. Next, an explanation of the cassette lid 12 that is detachably attached to the cassette case 11 will be provided. The cassette lid 12 is for covering the open surface of the cassette case 11 from above. A pair of engagement protrusions 30 for engaging in the engagement holes 13 formed in the cassette case 11 are provided to the rear edge of the cassette lid 12. An indented area 31 is formed in the front surface of the cassette lid 12. A resilient lock member 34, which is formed from an elbow 32 and a grip 33, is provided in the indented area 31. The elbow 32 depends downward from the lower surface of the cassette lid 12 before bending upward. The grip 33 is a continuation of upward-bending portion of the elbow 32 and protrudes horizontally. The position of the resilient lock member 34 corresponds to the position of the lock groove 15 so the resilient lock member 34 resiliently locks in the lock groove 15 when the lid is engaged in the opening of the cassette case 11. Further, a lock arm 35 is provided so as to depend from the lower surface of the cassette lid 12 at the left front side of the cassette lid 12. The position of the lock arm 35 corresponds to the position of the lock slot 19 so that the lock arm 35 resiliently locks in the lock slot 19 when the lid is engaged in the opening of the cassette case 11. A tape guide plate 36 provided depending from the left front tip of the cassette lid 12 is for guiding the print tape 3 in cooperation with the tape guide plate 16 of the cassette case 11 when the cassette lid 12 is engaged in the opening of the tape cassette case 11. Similarly, the guide arm 37 depending from the left corner of the cassette lid 12 forms the tape discharge area 28 in cooperation with the guide arm 29 formed in the cassette case 11 when the cassette lid 12 is engaged in the opening of the tape cassette case 11. Next, an explanation of operations for replacing the replaceable tape unit 10 after the print tape 3 in the tape cassette 1 is used up will be provided while referring to Figs. 1 through 3. To remove the cassette lid 12 from the cassette case 11, a user first clasps the grip 33 of the resilient lock member 34 and pulls upward. The lifting movement releases engagement of the elbow 32 from the lock groove 15 and engagement of the lock arm 35 from the lock slot 19 so that the cassette lid 12 can be pivoted on the engagement holes 13. When the grip 33 is further lifted upward, the cassette lid 12 is rotated upward on the engagement holes 13. The cassette lid 12 can be removed from the tape cassette case 11 when the engagement protrusions 30 are detached from the engagement holes 13 at a suitable orientation. Then the user removes the entire used up tape unit 10 from the tape spool housing area 42 of the cassette case 11 and loads a new replaceable tape unit 10 into the tape spool housing area 42. The user clasps the tip of the print tape 3 with his or her fingers and pulls the print tape 3 past the tape guides 22, 23, 24, and 25, the tape guide arm 16, and the tape feed roller 21 until it protrudes slightly from the cassette case 11 through the tape discharge area 28. During these operations performed while the cassette lid 12 is detached from the cassette case 11, the two clasps 5 and 6 abut against the upper surface of the flange 21A, thereby keeping the tape feed roller 21 rotatable and detachable with regards to the cassette case 11. Therefore, even when the cassette lid 12 is detached from the cassette case 11, the tape feed roller 21 will not fall out or be lost. Next, the user engages the engagement protrusions 30 of the cassette lid 12 into the engagement holes 13 of the engagement holes 13. Then, the user pivots the cassette lid 12 on the engagement holes 13 until the elbow 32 of the resilient lock portion 34 resiliently engages in the lock groove 15 and the lock arm 35 resiliently engages in the lock hole 19. This operation engages the cassette lid 12 in the cassette case 11 with a click so that the user knows that tape cassette 1 is assembled. This completes operations for replacing a used up print tape 3. The user then mounts the tape cassette 1 loaded with a new tape unit into the cassette mounting area of the label printer. Next, an explanation of other embodiments of the present invention will be provided while referring to Figs. 4 through 7. Fig. 4 is an enlargement of a portion of a tape cassette 50 according to a second embodiment wherein long-necked clasps 55 and 56 are integrally provided to the cassette case 51 so as to extend to near the cassette lid 52. Also, the tape feed roller 53 is not provided with the flange portion described in the first embodiment. The clasps 55 and 56 engage with a shoulder portion 53A of the tape feed roller 53 by abutting against the upper surface of the shoulder portion 53A. With this structure, the same effects obtained by the structure of the first embodiment can be obtained. Additionally, clasps 55 and 56 bend more easily, and therefore more easily receive the tape feed roller 53, because they are longer than the clasps 5 and 6 of the first embodiment. Fig. 5 is an enlargement of a portion of a tape cassette 60 according to a third embodiment wherein a tape feed roller 63 is provided with a groove portion 63A near its lengthwise center. Also, clasps 65 and 66 provided integrally to the cassette case 61 extend to the position of the groove portion 63A of the tape feed roller 63. The clasps 65 and 66 engage with the groove portion 63A of the tape feed roller 63 by protruding into the groove portion 63A. The groove portion 63A need not be provided near the center of the tape feed roller 63 but could instead be provided at the upper portion of the tape feed roller 63 near the cassette lid 62 or at the lower portion of the tape feed roller 63 near the floor of the cassette case 61. The structure of the third embodiment provides the same effects obtained by the structure of the first embodiment. Additionally, clasps 65 and 66 are easier to bend because they are longer than the clasps 5 and 6 of the first embodiment. Fig. 6 is an enlargement of a portion of a tape cassette 70 according to a fourth embodiment wherein the construction of a tape feed roller 73, a cassette case 71, and a cassette lid 72 are similar to the construction of the tape cassette 1 of the first embodiment. However, the outer peripheral surface 73B of the flange portion 73A is machined with a male-screw pattern and the inner peripheral surfaces 75A and 76A of respective clasps 75 and 76 are machined with female-screw patterns. The outer peripheral surface 73B of the flange portion 73A and the inner peripheral surfaces 75A and 76A of respective clasps 75 and 76 are machined to the same diameter. To engage the tape feed roller 73 with the clasps 75 and 76, the male-screw pattern at the outer periphery surface 73B of the flange portion 73A is engaged in the female-screw pattern at respective inner periphery surfaces 75A and 76A. Then the tape feed roller 73 is rotated until the male-screw pattern will disengage from the female-screw pattern so that the flange portion 73A is disposed between the floor of the cassette case 71 and the inwardly radially protruding portion of the clasps 75 and 76. Movement of the tape feed roller 73 in its axial direction will be restricted by the clasps 75 and 76 abutting against the flange 73B. As described in the first embodiment, the tape feed roller 73 will be rotatably supported by the clasps 75 and 76. It will be noted that in this embodiment, the clasps 75 and 76 are disposed in opposition to each other. Fig. 7a is an enlargement of a portion of a tape cassette 80 according to a fifth embodiment. Fig. 7b is an overhead view of the tape cassette 80. The tape feed roller 83 is provided with two flanges 83A and 83B aligned in parallel at its lower end. The lower flange 83B has a surface flush with a surface of the cassette case 81. The clasps 85 and 86 are disposed in opposition to each other. A groove 83C is formed between the two flanges 83A and 83B. Two clasps 85 and 86 are integrally formed to the cassette case 81 so as to engage in the groove 83C of the tape feed roller 83. With this structure, the clasps 85 and 86 abut against the flanges 83A and 83B thereby restricting movement of the tape spool 83 in the direction of its axis of rotation. The same effects obtained by the structure of the first embodiment can be obtained. The groove 83C could be provided adjacent to the lid 82, in which case the clasps 85 and 86 could be provided to the lid 82. The groove 83C could alternatively be provided at the upper portion of the tape feed roller 83 near the cassette lid 82 or near the center of the tape feed roller 83, rather than at the lower portion of the tape feed roller 83. In these cases, clasps could be formed either to the floor of the cassette case 81 or to the lid 82 so as to extend to the area where the groove 83C is provided. Fig. 8 is an enlargement of a portion of a tape cassette 90 according to another example wherein the tape feed roller 93 is provided with engagement clasp members 95 and 96 at its upper end. An upper opening 97 is formed in the cassette lid 92 at a position thereof corresponding to where the upper end of the tape feed roller 93 is to be disposed. Similarly, a lower opening 98 is formed in the floor of the cassette case 91 at the position thereof where the tape feed roller 93 is to be disposed. Also, the tape feed roller 93 is provided with a flange 93A and a base 93B at its lower end. The tape feed roller 93 is engaged to the cassette lid 92 in the following manner. The user clasps the tape feed roller with his or her fingers and firmly inserts the engagement clasp members 95 and 96 into the upper opening 97. This causes the engagement clasp members 95 and 96 to bend and enter the upper opening 97. When the cassette lid 92 is attached to the cassette case 91, the base 93B of the tape feed roller 93 becomes mounted in the lower opening 98 and is locked in place by the peripheral edge of the lower opening 98. This example differs from the embodiments previously described in that the tape feed roller 93 is rotatably supported to the cassette lid 92. Structures provided for rotatably supporting the tape feed roller 93 to the cassette lid 92 can be the same as those described in the embodiments, that is, can include clasps and flanges or clasps and grooves. For example, the first through fourth embodiments described clasps being formed integrally to the cassette case, but the clasps could be formed to the lid instead. Further, the engagement clasp members 95 and 96 can be provided to the lower portion of the tape feed roller so as to engage in the lower opening 98. According to the tape cassette of the present invention having the above-described structure, because the components disposed in the cassette case are detachably maintained by the maintaining means, the components will not fall out or get lost even when the lid of the cassette case is in an opened condition. Also, when the components are rollers for feeding the tape, the maintaining means effectively maintains the rollers in place so as to be rotatable and detachable to the lid or the cassette case. Also, because the maintaining means is a clasp integrally formed to the lid or the cassette case and because the rollers include an engagement portion for engaging with the clasp, the roller is effectively maintained detachable and rotatable to the lid or the cassette case. Also, when the maintaining means is an engaging clasp formed to the roller and engaging clasp engages with an opening provided to the lid or the cassette case, the roller is just as effectively maintained detachable and rotatable to the lid or the cassette case. While the invention has been described in detail with reference to specific embodiments thereof, it would be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the scope of the attached claims. For example, the present embodiments discuss the present invention applied to a tape cassette with only one tape feed roller near the tape discharge area 28. However, this is because the print tape used in the tape cassettes of the present embodiments is made from thermal paper. Tape cassettes housing a variety of tapes also require feed rollers and other components disposed at other positions as well. Therefore, these other components can also be supported in the same manner as the tape feed roller of the above-described embodiments. Also, the present embodiments described a tape cassette used in a label printer. However, the present invention can be applied to any tape cassette constructed so that the tape is replaceable. Also, the present invention can be applied to devices other than tape cassettes, as long as they are constructed so that tapes are replaceable.

Claims: A tape cassette (1, 50, 60, 70, 80) comprising: a cassette case (11, 51, 61, 71, 81); a lid (12, 52, 62, 72, 82) openably provided with the cassette case; a tape (3) disposed in the cassette case; a roller (21, 53, 63, 73, 83) disposed in the cassette case at a certain position and posture with regards to one of the lid and the cassette case when the lid is in a closed condition the roller having an engagement portion (21A, 53A, 63A, 73A, 83A, 83B); maintaining means for detachably maintaining the roller in the certain position and posture with regards to the one of the lid and the cassette case when the lid is in an opened condition; characterized in that the maintaining means includes a clasp (5, 6, 55, 56, 65, 66, 75, 76, 85, 86) integrally formed at the one of the lid and the cassette case, the clasp engaging with the engagement portion to rotatably and detachably maintain the roller at the one of the lid and the cassette case. A tape cassette as claimed in claim 1, wherein the engagement portion includes a flange radially protruding from the roller. A tape cassette as claimed in claim 2, wherein the clasp (5, 6, 75, 76) engages with the flange (21A, 73A) by extending to a flange surface that faces away from the one of the lid and the cassette case, the clasp thereby restricting movement of the roller in a direction following an axis of rotation of the roller. A tape cassette as claimed in claim 2 or 3, wherein an inner surface of the clasp (75, 76) is formed with a screw pattern and an outer surface of the flange (73A) is formed with another screw pattern engageable with the screw pattern of the clasp. A tape cassette as claimed in claim 2 wherein the clasp (85, 86) engages with the flange (83B) by extending to a flange surface that is substantially flush with a surface of the one of the lid (82) and the cassette case (81), the clasp thereby restricting movement of the roller (83) in a direction following an axis of rotation of the roller. A tape cassette as claimed in claim 1, wherein the engagement portion includes a shoulder surface (53A) at an end of the roller (53) opposite another end that confronts the one of the lid (52) and the cassette case(51). A tape cassette as claimed in claim 1, wherein the engagement portion includes a groove (63A) formed around a circumference of the roller (63).

Inventors: KAWAI TAKAMITSU, KAWAI, TAKAMITSU, KAWAI, TAKAMITSU, C/O BROTHER KOGYO K. K.
Applicants: BROTHER IND LTD, BROTHER KOGYO KABUSHIKI KAISHA
Application year: 1995
Main classification: B41J32
IPC codes: B41J32, B41J3, B41J15