Disc cartridge with disc locking mechanism

Abstract: The present disc cartridge has a lower casing element (1) providing a housing for a recording disc with a central hole. The bottom (6) of the lower casing element has an opening (7), a first part (7a) of which is designed to provide a passage for a shaft for driving the disc in rotation, and a second part (7b) of which is designed to provide access for a disc-reading device. A casing cover (2) provides a plane wall facing the bottom of the lower casing element. The cartridge further comprises a removable protector member (3) having a bottom plate (15) which provides a wall closing at least said second part of the opening of the bottom of the lower casing element, as well as engaging means (35, 36) for engaging the lower casing element (1). The protector member comprises locking means (38) arranged for becoming engaged in the central hole of the recording disc placed in the lower casing element, so as to maintain the recording disc in a fixed position with respect to the lower casing element.

Description: This invention relates to a disc cartridge for accommodating recording discs capable of having information recorded thereon and read out by an appropriate reading apparatus. More particularly, the invention relates to a disc cartridge as described in the introductory clause of claim 1. Such a cartridge usually comprises a casing designed to accomodate the disc and to allow the read-out and/or the recording of information while the disc is housed in said casing. The recording discs concerned may be of the type generally designed as "compact disc" or "CD", and more particularly information carrying discs called "CD ROM", although the invention is in no way limited to this type of disc. A disc cartridge of the type concerned by the invention is described in EP-A-0570342 disclosing the precharacterising features of claims 1 and 4. A drawback of this and other prior art cartridges and casings results from a certain freedom of the disc to move within the casing when the same is not inserted in a reading or recording apparatus, in particular during transportation. Such a movement of the disc inside the casing produces frictional wear resulting in fine particles which can come to lie on the surface of the disc and create perturbations in the reading or recording process. In the case of recordable discs, currently designated as CDR:s, it is particularly important that the surface of the disc remains free from dust or other contaminations before the disc is being recorded, which is not assured when the disc is housed in a prior art casing where it can move inside its compartment. A main object of the present invention is to provide a disc cartridge which overcomes the above drawback of the prior art casings and cartridges. This is achieved by the features recited in the characterizing clause of claim 1 and 4. Preferred embodiments of the invention are described in claims 2 to 15. Further aspects, objects and advantages of the invention will become apparent from the following description of various embodiments thereof as represented, by way of example, in the appended drawings, in which: Fig. 1 is a perspective view showing a first embodiment of a disc cartridge comprising a protector member for use in accordance with the present invention; Fig. 2 is a cross-sectional view showing a detail of the cartridge of Fig. 1; Fig. 3 is a plan view showing a removable locking member; Fig. 4 is a cross-sectional view of the locking member of Fig. 3; Fig. 5 is a plan view showing a protector member according to another embodiment of the cartridge of the invention; Fig. 6 is a cross-sectional view of the protector member of Fig. 5; Fig. 7 is a plan view showing yet another embodiment of a protector member of a cartridge according to the invention; Fig. 8 is a cross-sectional view of the protector member of Fig. 7; Fig. 9 is a plan view showing yet another embodiment of a protector member of a cartridge according to the invention; Fig. 10 is a cross-sectional view of the protector member of Fig. 9; Fig. 11 is a plan view showing a protector member according to still another embodiment of the cartridge according to the invention; Fig. 12 is a plan view showing a removable central locking member of the cartridge of Fig. 11; Fig. 13 is a cross-sectional view of the locking member of Fig. 12; Fig. 14 is a perspective view showing an embodiment of a lower casing element and cover of a cartridge similar to that of Fig. 1; Fig. 15 is a plan view of a combined protector and locking member for use with a casing element according to Fig. 14; and Fig. 16 is a cross-sectional view of the locking member of Fig. 15. A disc cartridge as shown in Fig. 1 comprises a lower casing element 1, a casing cover 2 and a protector member in the form of a drawer 3. The lower casing element 1 includes a compartment 4 for receiving a disc, not shown, this compartment being defined by three arcuate wall portions 5a, 5b, 5c. The bottom 6 of the lower casing element 1 has an opening 7, one part 7a of which, as defined by an arcuate edge 7'a, is arranged in the central part of the bottom 6 and is designed to provide a passage for a shaft for driving the disc in rotation when the casing formed of parts 1 and 2 is placed inside an apparatus for reading the disc in a manner known per se . The remaining of the opening 7 is a part 7b, as defined by two edges 7'b, arranged to provide access for a disc reading device, for example an optical laser reading device, not shown, belonging to the reading apparatus. The position, the dimensions and the shape of the opening 7 as well as more generally the shape and the outer dimensions of the lower casing element 1 correspond to those of the casings currently available on the market for discs of the CD-ROM type. The casing cover 2 is designed so that it may be fastened removably to the lower casing element 1 after insertion of a disc, not shown, in the compartment 4. The fastening of the cover 2 on element 1 is ensured by four hooked retaining fingers 8 consisting of thin strips protruding from the bottom 6 and inwards of element 1 in the vicinity of each one of its corners and running parallel to side-walls 9 of element 1. As shown in Fig. 2, the end of each one of these fingers 8 is provided with a hook 10 arranged so as to snap back on a ledge 11 protruding inside an opening 12 arranged adjacent each one of the corners of the cover 2. For separating the cover 2 from the lower element 1, each hook 10 can be released from the ledge 11 by a slight flexion of the corresponding finger 8. A circle shown in phantom in Fig. 1 indicates the location of an optional housing 13 on the lower face 2b of cover 2. This housing 13, when provided, is designed for retaining a rotatory disc clamping element similar to that of conventional casings. The front-wall 9' of the lower casing element 1 has a recessed portion 14 which is used in particular for the correct insertion of the casing into a disc reading apparatus. The drawer 3 is arranged for receiving, by a translatory movement as illustrated in Fig. 1, the casing assembly comprised of the lower casing element 1 closed by its cover 2. The drawer has a bottom 15, two side-walls 16 and a back-wall 17. Two side-ledges 19 extending from the free edges of the side-walls 16 over a portion of the length of these edges and an end-ledge 20 extending from the free end of the back-wall 17 are arranged for retaining the assembly formed by the casing element 1 and its cover 2 when the same is placed in the drawer 3. The lower casing element 1 has lateral recesses such as 23 which cooperate with tongue-like portions 24, 25 in the side walls 16 of the drawer 3 to retain the casing element 1 inside the drawer. The drawer 3 is shown in Figure 1 to have the full depth of the lower casing element 1, i.e. its bottom 15 and side-walls 16 cover at least approximately the entire bottom 6 and side-walls 9 of the lower casing element. In this case, preferably an arcuate cut-out 18 is provided in the frontal edge of bottom 15, which makes it easier to grip the casing with the hand when removing it from the drawer 3. Fig. 1 and the cross-sectional view of Fig. 2 show the bottom 6 of the casing element 1 being slightly reduced in height over an area 27 of that bottom indicated by a dotted line in Fig. 1. Furthermore, Fig. 1 shows a hole 28 in the bottom 6 which is one of a pair of holes provided symmetrically in the vicinity of opposite lateral walls 9. Figures 3 and 4 show an elongated locking member 30 which is a substantially flat part of plastic material adapted for being removably inserted into the opening of the lower casing element 1. The outer shape of locking member 30 therefore corresponds to that of the border of the opening 7 and its thickness is such that, when inserted, the upper surface 31 and the bottom surface 32 of its body portion 33 are flush, respectively, with the inner surface of the bottom 6 surrounding the opening 7 and with the outer surface of the bottom 6 where the same has the greatest thickness, i . e . outside the zone 27. The border of the locking member 30 has a step-shaped profile as shown at 34 in Figures 3 and 4, for fitting into the opening 7. Furthermore, the locking member 30 has two extensions 35, 36, the free ends of which are level with the front-wall portion 9' of the lower casing element 1 when the locking member 30 is fitted into the opening 7. Accordingly, when the lower casing element 1 is inserted in the drawer 3, the locking member is maintained in a well determined fixed position with respect to the bottom 6 of the lower casing element. The locking member 30 is provided with a crown-shaped portion 37 which comprises protruding tongue-shaped locking elements 38 arranged for fitting into the central hole of a recording disc to hold the same in a fixed position with respect to the casing 1, 2, more particularly in a centered position with respect to the walls or wall portions of its compartment, such as the compartment 4. This is quite important in order to avoid frictional wear between the disc and the casing as it otherwise occurs, in particular during transportation and handling of the cartridges. Figures 5 and 6 show another embodiment of a protector member which can be used in place of the above described drawer in connection with a disc casing 1, 2 as shown in Figures 1 and 2 and a locking member 30 as shown in Figures 3 and 4. The protector member 39 comprises a bottom plate 40 and two wall-portions, namely front-wall and back-wall portions 41, 42. These wall portions are provided with respective ledge portions 43, 44 and 45, 46 which extend from the free edges of the wall portions and preferably have a width so as to overlap only the corresponding wall portions of the lower casing element 1, but not the cover 2. This makes it possible to open and close the disc casing even when the same is placed in its protector member 39. A ledge portion 47 extending inwardly from the front-wall portion 41 has a length and width which are smaller than the length and depth of the recessed wall-portion 14 of the lower casing element and the length and depth of a corresponding cut-out of the cover 2 shown in Fig. 1. The bottom plate 40 of the protector member 39 is provided with two protruding parts 48, 49 having the form of short pins with a tapered or rounded end. These protruding parts extend from the bottom plate 40 at locations corresponding to the location of corresponding holes in the bottom of the lower casing element 1, one of which, 28, is shown in Fig. 1. The protector member 40 has no lateral walls and its width between its lateral edges 50, 51 is equal to that of the lower casing element 1. This makes it possible to insert the cartridge formed by the assembly of parts 1, 2 and 39 into ususal storage means provided for storing conventional disc casings of standardized dimensions. The assembly and disassembly of the disc casing 1, 2 and the protector member 39 make use of the inherent flexibility of the bottom plate 40 which allows resilient bending to separate the opposite wall portions 41, 42 by the small distance necessary for placing the lower casing element 1 between the same. This bending can easily be effected by pressing on the ledge portion 47 while holding the member 39 on the opposite side. The protruding parts 48, 49 cooperate with the corresponding holes 28 in the bottom 26 of the lower casing element to position and maintain the same on the bottom plate 40. Figures 7 and 8 show a protector member 39' in which the bottom plate 40' of the protector member itself is provided with a protruding locking portion 52 comprising a peripheral ridge 53 having the shape of the border of the opening 7 in the bottom of the lower casing element 1. The locking portion 52 is thus arranged to fit into the opening 7. This provides an improved closure of this opening and also maintains the lower casing element in its position. This latter function can replace that of the protruding parts 48, 49 of Figures 5 and 6, but such protruding parts are preferably provided in addition. The locking portion further comprises a crown-shaped portion including resilient locking elements 54 projecting from the bottom 40' for becoming engaged in the central hole of a recording disc placed inside the casing 1, 2. The function of these locking elements is the same as that of the locking elements of the removable locking member 30 described in relation with Figures 3 and 4. Figures 7 and 8 further show the bottom plate 40' having a cut-out portion 55 which makes it possible to hold the disc casing 1, 2 when assembling the same with the protector member or disassembling the same therefrom. Figures 9 and 10 show another embodiment of a protector member similar to the embodiment of Figures 5 and 6. In Figures 9 and 10, the bottom plate 40'' of a protector member 39'' is provided with protruding positioning portions 56, 57 and 58 which are formed as ridges projecting from the bottom plate. The arrangement of these ridges is such that it provides for a precise positioning of a removable locking member as described in relation with Figures 3 and 4. More particularly, the ridges 56 and 57 are arranged to be placed on either side of the body part 33 of that locking member and ridge 58, having for example a circular shape, is placed so that it penetrates into a corresponding circular recess in the bottom surface 32 of the locking member when that member is placed on the bottom plate 40". This ensures in particular that the central, crown-shaped portion 37 of the locking member is well centered with respect to the disc compartment. The protector member of Figs. 9 and 10 is, like that of Figs. 5 and 6, designed for use with a separable locking member, the structure and the function of which have been described in relation with Figures 3 and 4. It is to be mentioned that such a separable locking member can also be used in connection with a protector member as shown in Figures 5 and 6, although the presence of positioning means, as provided by the ridges 56, 57 and 58, is preferred. Figures 11 to 13 illustrate an alternative solution for providing a locking function to fixedly maintain a recording disc in the cartridge, by means of a removable locking member. In the embodiment of Fig. 11, the protector member 39"' is provided with a central hole 59 through its bottom plate 40"'. The outer surface of the bottom plate 40"' has a small circular recess 60 surrounding the hole 59. Figures 12 and 13 represent a removable locking member 61 of circular shape adapted for fitting into the hole 59 and recess 60 from the outer or bottom side of the plate 40"', so that the lower surface of the member 61 is flush with the outer surface of the protector member. In a similar way as the crown-shaped locking portion described in relation with Figures 7 and 8, the locking member 61 has a series of tongue-shaped locking elements 62 which are arranged for penetrating into the central hole of a recording disc placed inside a casing 1, 2. While the locking function of the locking member 61 is similar to that of the removable locking member 30 of Fig. 3, the embodiment of a cartridge in accordance with Fig. 11 automatically provides for removal of the locking member when the disc casing 1, 2 is separated from the protector member. A similar central locking member adapted for insertion through a central hole in the protector member can also be used in a structure where the disc casing is arranged for being placed in the protector member by a translatory movement. In such a case, the locking member will have to be removed from the bottom plate of the protector member from the outside thereof. It is further to be noted that the locking elements of the locking member can have various appropriate shapes to fulfill their locking/clamping function for holding the disc in a well-defined fixed position inside its casing when they are engaged in the central hole of the disc. Figures 14, 15 and 16 illustrate a cartridge according to the invention which comprises a disc casing with a lower element 1', similar to the one illustrated in Fig. 1 but adapted so that a combined protector and locking member 30', as shown in Figures 15 and 16, can be removably mounted thereon. The protector and locking member 30' is similar to the locking member 30 of Figures 3 and 4, but is provided with a nose 34' and a wall and ledge portion 35' bearing two protrusions 36', 36". In Figures 14 to 16, parts 2, 9, 9', 27, 28, 31-34, 37 similar to those of Figures 1, 3 and 4 are designated by the same reference numbers. The lower casing element 1' has a notch 7c extending beyond the opening 7 ' in its bottom 26 and its recessed front-wall portion 14' has two holes 29' and 29". The protrusions 36', 36'' are adapted to be inserted, respectively, into the holes 29', 29'' and the nose 34' is adapted to cooperate with a corresponding portion of the bottom 26 so that the member 30' can be clipped onto the lower casing element 1'. When mounted, the member 30' is fitted in and fully closes the opening 7', while its locking elements 38 are maintaining a disc, not shown, in a fixed position inside the disc casing, in a similar manner as in the case of the locking member of Figures 3 and 4. To remove the member 30', the same can be seized by the ledge portion of 35' and drawn out until the nose 34' can pass through the notch 7c, the central portion of the member 30' being then withdrawn from the hole of the disc and the whole member 30' removed. The cartridge according to the present invention can be used with standard disc casings or disc casings designed as described above. The standardized dimensions and arrangements of such casings allow, in each case, the assembly thereof with a protector member to form a cartridge in accordance with the present invention.

Claims: A disc cartridge including a disc casing which comprises a lower casing element (1; 1') constructed to provide a housing for a recording disc having a central hole, the bottom of the lower casing element comprising an opening (7; 7'), a first part (7a) of which is designed to provide a passage for a shaft for driving the disc in rotation, the shaft belonging to a disc-reading apparatus, and a second part (7b) of which is designed to provide access for a disc-reading device belonging to the disc-reading apparatus, and a casing cover (2) providing a plane wall facing the bottom (6; 26) of the lower casing element, said cartridge further comprising a removable protector member (39'; 30'), said protector member comprising a bottom plate (40'; 33) providing a wall closing at least said second part of the opening of the bottom of the lower casing element, as well as engaging means (43, 44, 45, 46, 48, 49; 36', 36") for engaging the lower casing element (1; 1') so as to keep together the protector member and the lower casing element, characterized in that said protector member comprises locking means (54; 38) arranged for extending through the first part of said opening and for becoming engaged in the central hole of the recording disc placed in the lower casing element, so as to maintain the recording disc in a fixed position with respect to the lower casing element, said protector member being attachable to and removable from the lower casing element. A disc cartridge according to claim 1, characterized in that said protector member (30') comprises at least a first portion (37) arranged for fitting into said first part of the opening (7') in said bottom (26) of the lower casing element (1'). A disc cartridge according to claim 1, characterized in that said protector member (30') comprises a second portion which is arranged for fitting into said second part of the opening (7') in said bottom (26) of the lower casing element (1'). A disc cartridge including a disc casing which comprises a lower casing element (1; 1') constructed to provide a housing for a recording disc having a central hole, the bottom of the lower casing element comprising an opening (7; 7'), a first part (7a) of which is designed to provide a passage for a shaft for driving the disc in rotation, the shaft belonging to a disc-reading apparatus, and a second part (7b) of which is designed to provide access for a disc-reading device belonging to the disc-reading apparatus, and a casing cover (2) providing a plane wall facing the bottom (6; 26) of the lower casing element, said cartridge further comprising a removable protector member (3; 39"), said protector member comprising a bottom plate (15, 40") providing a wall closing at least said second part of the opening of the bottom of the lower casing element, as well as engaging means (19, 20; 43, 44, 45, 46, 48, 49) for engaging the lower casing element (1; 1') so as to keep together the protector member and the lower casing element, characterized in that the cartridge further comprises a removable locking member (30, 61) having locking means (38) arranged for extending through the first part of said opening and for becoming engaged in the central hole of the recording disc placed in the lower casing element, so as to maintain the recording disc in a fixed position with respect to the lower casing element. A disc cartridge according to claim 4, characterized in that said locking member is placed between the bottom plate (15; 40") of the protector member and the bottom (6) of the lower casing element. A disc cartridge according to claim 4, characterized in that said protector member (3) forms a drawer comprising said bottom plate (15), two side-wall portions (19) and a back-wall portion (17), each of said wall portions being provided with a ledge (19, 20) Oextending from a free longitudinal edge of said wall portions over at least a portion of the length of said free edge so as to retain said lower casing element (1) in said drawer (3). A disc cartridge according to claim 6, characterized in that said ledge (20) of said back-wall (17) is arranged for retaining said cover (2) of the lower casing element when said casing element with its cover is placed in said drawer (3). A disc cartridge according to claim 6, characterized in that said ledges (19, 20) are dimensioned so as to make possible the closing or the opening of said disc housing when said lower casing element (1) is placed in said drawer (3). A disc cartridge according to claim 1 or 4, characterized in that said protector member comprises a flexible bottom plate (40'; 40", 40"'), a front-wall portion (41) and a back-wall portion (42), said wall portions being each provided with a ledge extending from a free longitudinal edge of said wall portions over at least a portion of the length of said free edge so as to retain said lower casing element when the lower casing element is placed in said protector member, said ledges (43-46) having a width allowing said lower casing element to be removed from the protector member when at least one of said front-wall and back-wall portions is being pressed manually so as to become separated from said casing element as a result of a bending of said bottom plate. A disc cartridge according to claim 4, characterized in that said removable locking member (30) comprises at least a first portion (37) arranged for fitting into said first part (7a) of the opening in said bottom of the lower casing element, said locking member being arranged for being maintained in place when said first portion of the same is fitted into said first part of said opening and the lower casing element is placed in the protector member, said first portion of said locking member comprising said locking means (38). A disc cartridge according to claim 6, characterized in that said locking member (30) comprises a second portion extending across said second part (7b) of the opening in said bottom (6) of the lower casing element and up to said back-wall portion (17; 41) of said protector member (3; 39). A disc cartridge according to claim 7, characterized in that at least a part of said second portion of said locking member is arranged for fitting into said second part (7b) of the opening in said bottom (6) of the lower casing element. A disc cartridge according to claim 9, characterized in that the bottom (6) of said lower casing element has at least one hole (28), said bottom plate of said protector member comprising at least one protruding part (48, 49) adapted for fitting into said hole of the lower casing element. A disc cartridge according to claim 9 or 13, characterized in that said bottom plate (40') of said protector member (39') comprises a protruding locking portion (52) arranged for fitting into at least said first part of said opening in the bottom of said lower casing element, said locking portion comprising said locking means (54). A disc cartridge according to claims 9 and 10, characterized in that the bottom plate (40") of said protector member (39") has protruding positioning portions (56, 57, 58) arranged for cooperating with border portions of said locking member to define the position thereof with respect to said bottom plate. A disc cartridge according to claim 4, characterized in that it comprises a removable central locking member (61), the bottom plate (40"') of said protector member (39"') comprising a central hole (59), arranged for receiving said removable central locking member, said locking member being adapted for fitting into said hole and for becoming engaged in the central hole of said recording disc, so as to maintain said disc in a fixed position with respect to the bottom of said lower casing element. A disc cartridge according to any one of claims 1-3, characterized in that the protector member (30') is adapted to be removed from the casing (1') by being drawn slidably in the direction of the bottom plate (27) out of engagement with the casing. A disc cartridge according to claim 17, characterized in that the protector member (30') comprises a nose (34') cooperating with a portion of the bottom plate (27) to retain the protector member (30') to the bottom plate.

Inventors: TRICART PHILIPPE, TRICART, PHILIPPE
Applicants: CD PLANT TECVAL S A, CD PLANT TECVAL S.A.
Application year: 1997
Main classification: G11B23
IPC codes: G11B23, G11B33