Optical disc cartridge with structure for preventing the dislocation of a spring.

Abstract: A structure for preventing the dislocation of a spring in an optical disk cartridge wherein a shutter is opened and closed in accordance with a sliding movement of a sliding jig provided in the inner portion of the shutter and joined to the spring contacting portions of cartridge case via a spring, characterized in that the spring contacting portions of the cases consist of the surfaces of a contacting wall, and upper and lower walls extending from the contacting wall, the lower wall being provided with a spring dislocation preventing projection.

Description: This invention relates to an optical disc cartridge with a structure for preventing the dislocation of a spring. An optical disk protecting container consisting of a cartridge type container has recently been used most conveniently. In this container, an optical disk base 22 is housed in a cartridge 21 as shown in Figure 7, and the disk base 22 is not normally exposed. The disk protecting container is formed so that, when it is inserted into a reader, a shutter 23 provided on the cartridge 21 is opened manually or automatically to cause a part of the disk base 22 to be exposed. The opening and closing of the shutter 23 are done in accordance with the laterial movements of a sliding jig joined to an inner portion of the shutter 23. To be more precise, the cartiridge 21 consists of two cases 21a, 21b (cases on the sides of A and B surfaces) molded to substantially the same shape, as shown in Figures 7 and 8. One side, on which slide portions are formed, of the cases 21a, 21b is provided with rails 25a, 25b. The slide jig 24 constituting another member is provided with jig sliding grooves 26a, 26b the size of which is in agreement with that of the rails 25a,25b and the sliding jig 24 is held between the cases 21a, 21b slidably. The sliding jig 24 is joined resiliently to the spring contacting portions of the cartridge cases via a spring 27 so that the opening and closing of the shutter 23 are thereby controlled. The sliding jig 24 is normally in the condition shown in Figure 10, with the shutter closed. In order to produce the optical disk cartridge, the sliding jig 24 is held between the cases 21a, 21b first as described above. After the cartridge is formed by using this step, a spring 27 the free end portions of which are bent at right angles so as to increase the contact surface area therof is inserted thereinto from the opened surfaces 28 of the sliding portions of the cases. In a conventional cartridge of this kind, the spring 27 is engaged at its free end portions 29, 30 with a free end portion (contacting portion) 31 of the sliding jig 24 and the contacting surfaces 32 of the cases, and the dislocation of the spring is prevented by only the resilient force thereof. EP-A-0 271 997 discloses an example of such a conventional cartridge. An optical disk is originally a precision product and handle as carefully as possible. When the optical disk is handled normally, the spring does not come off even if the spring is formed as mentioned above, but when the cartridge is dropped by mistake, the spring comes off in some cases due to the impact of the dropped cartridge. When the spring comes off, the shutter opening means natually becomes unserviceable, so that it becomes necessary to open the screwed cartridge cases and set the spring again. This requires considerable labor. SUMMARY OF THE INVENTION: In accordance with the invention there is provided an optical disc cartridge with a structure for preventing the dislocation of a spring wherein a shutter is opened and closed in accordance with a sliding movement of a sliding jig provided in an inner portion of the shutter and joined to the spring contacting portions of cartridge cases via a spring, characterized in that the spring contacting portions of the cases consist of the surfaces of a contacting wall and upper and lower walls which are provided on the contacting wall, a spring dislocation preventing projection being provided on the lower wall. BRIEF DESCRIPTION OF DRAWINGS: A structure for preventing the dislocation of a spring will now be described with reference to the accompanying drawings. Figure 1 is a plan view showing the construction of a spring contacting portion of a conventional optical disk cartridge; Figure 2 is a plan view showing the construction of a spring contacting portion of the disk cartridge according to the present invention; Figures 3 and 4 show the condition of these spring contacting portions viewed in the direction of arrows in (from the left-hand side of) Figures 1 and 2, respectively; Figure 5 is a plan view showing the construction of the spring contacting portion of a sliding jig; Figure 6 shows the condition of the spring contacting portion of the sliding jig viewed in the direction of an arrow in (from the right-hand side of) Figure 5; Figure 7 is a perspective view of a conventional optical disk cartridge in which the invention can be applied and Figure 8 is a plan view showing a sliding portion of the conventional optical disk cartridge. Figure 1 shows the condition of a cartridge side spring contacting portion of a conventional structure of this kind, Figure 2 a spring dislocation preventing projection provided on a lower wall in accordance with the techniques of the present invention, and Figures 3 and 4 the condition viewed in the direction of the arrows in (from the left-hand portions of) Figures 3 and 4. In a conventional cartridge, the contacting portion, with which a free portion of a spring is engaged, of one case 21b alone is provided with walls 33, 34 at the upper and lower portions thereof, and the free end portion of the spring is inserted from an opening 35 into and held in the space between these walls. However, when the cartridge is dropped as referred to above, the spring comes off in many cases from the opening 35 due to the impact force. According to the present invention, a spring dislocation preventing projection 36 is provided on a lower wall 34, so that the spring does not come off even when a considerably large impact is imparted thereto. The shape of this dislocation preventing projection is not specially limited, and it may be formed to the same width as the lower wall 34 as shown in Figure 4. The height of this projection is preferably set as large as possible in view of the spring dislocation preventing effect. Accordingly, the length of the opening (spring inserting portion) 35 may be set to a required minimum level, i.e., substantially equal to the diameter of the free end portion of the spring. This dislocation preventing projection 16 can be molded integrally with a case by using a metal mold obtained by suitably modifying a conventional metal mold. According to the present invention, the construction of the part of the contacting portion which is other than the spring dislocation preventing projection 36 is not specially limited, and the construction of the contacting portion as a whole may be identical with that of a conventional contacting portion as shown in Figures 3 and 4. The construction of the contacting portion of the other case 21a may be determined suitably in accordance with the shape of the free end portion of the spring so that the inserting of the spring and the dislocation thereof can be done easily and preventing effectively, respectively. A contacting portion 31, i.e., the free end portion of the sliding jig 24 is also preferably formed as described above, for example, as shown in Figures 5 and 6. Even when the optical disk cartirdge provided with a spring dislocation preventing structure according to the present invention is dropped by mistake, the spring does not come off, so that this cartridge is very useful in practice, When a conventional optical disk cartridge which is not provided with a spring dislocation preventing spring was subjected to 3-30 time drop test, the spring came off all times, whereas, when an optical disk cartridge according to the present invention was subjected to a 30 time drop test, no problems arose.

Claims: An optical disc cartridge with a structure for preventing dislocation of a spring (27) in the cartridge (21) wherein a shutter (23) which is opened and closed in accordance with a sliding movement of a sliding jig (24) provided in an inner portion of said shutter and joined to the spring contacting portions of the cartridge case via a spring (27), characterized in that said spring contacting portions of said case consist of the surfaces of a contacting wall (32) and upper and lower walls (33, 34) which are provided on said contacting wall (32), and a spring dislocation preventing projection (36) being provided on said lower wall, The cartridge as recited in claim 1, wherein the spring dislocation preventing projection (36) is spaced from the contacting portions of the case, and the cartridge case having a side wall which is in engagement with the lower wall and the spring dislocation preventing projection. The cartridge as recited in claim 2, wherein the spring dislocation preventing projection and the upper wall have an opening defined therebetween, and the opening being adjacent to the side wall of the cartridge case. The cartridge as recited in claim 3, wherein the upper wall, the lower wall, the contacting portion of the cases and the projection all defining a recess, an end of the spring being insertable into the recess through the opening between the spring dislocation preventing projection and the upper wall, the opening having a length which generally corresponds to a diameter of the end of the spring, the spring dislocation preventing projection preventing the end of the spring from falling from the recess. The cartridge as recited in claim 1, wherein the spring has at least on bend therein such that the end of the spring and a remainder of the spring have an L-shape, the end of the spring being insertable through the opening into the recess and being held therein by the projection. The cartridge as recited in claim 5, wherein the recess generally has a rectangular configuration with the upper and lower walls being generally parallel and with the contacting portion of the cases and the projection being generally parallel. The cartridge as recited in claim 1, wherein the recess generally has a rectangular configuration with the upper and lower walls being generally parallel and with the contacting portion of the cases and the projection portion being generally parallel. The cartridge as recited in claim 1, wherein a length of the lower wall is greater than a length of the upper wall. The cartridge as recited in claim 8, wherein a width of the upper wall is generally the same as a width of the lower wall. The cartridge as recited in claim 1, further comprising a second spring dislocation preventing projection, the second spring dislocation preventing projection being provided on the sliding jig, the spring having two ends, one end of the spring being received in a recess formed by the upper and lower walls, the contacting portion of the cases and the first projection and the other end of the spring being received in a recess formed in the jig. The cartridge as recited in claim 10, wherein a jig opening is provided to the recess in the jig, the other end of the spring being insertable into the recess in the jig through the jig opening. The cartridge as recited in claim 1, wherein the spring dislocation preventing projection is formed integrally with the lower wall. The cartridge as recited in claim 1, wherein the end of the spring is generally perpendicular to the rest of the spring, the end of the spring points toward the side wall of the cartridge case which is in engagement with the lower wall and the spring dislocation preventing projection. The cartridge as recited in claim 1, wherein the side wall of the cartridge case which is in engagement with the lower wall and the spring dislocation preventing projection is generally perpendicular to the spring contacting portions of the cartridge case. The cartridge as recited in claim 1, wherein the side wall of the cartridge case which is in engagement with the lower wall and the spring dislocation preventing projection is generally perpendicular to the spring dislocation preventing projection, the lower wall and the upper wall.

Inventors: AOKI CHIHIRO, HAMANO SEITARO, HIRAMATSU YASUSHI, KAMAKURA KUNIHITO, OHTA SEICHI, AOKI, CHIHIRO, HAMANO, SEITARO, HIRAMATSU, YASUSHI, KAMAKURA, KUNIHITO, OHTA, SEICHI
Applicants: DAICEL CHEM, DAICEL CHEMICAL INDUSTRIES, LTD.
Application year: 1990
Main classification: G11B23
IPC codes: G11B23, G11B33