Abstract:
Cartridge having a housing which includes a lower cartridge part and an upper cartridge part. The lower cartridge part and the upper cartridge part are connected together. Each of the lower cartridge part and the upper cartridge part include side walls and a recess which is adapted to receive a tape guiding pin. A reel is rotatably mounted in the housing. A tape guiding pin clasp fixes the tape guiding pin in the recesses of the lower cartridge part and the upper cartridge part. The tape guiding pin is located in a region of a tape exit opening that is located in a corner of the housing. The tape exit opening is adapted to be closed by a sliding door. The tape guiding pin clasp includes a mechanism that secures at least one side wall of the lower cartridge part to at least one side wall of the upper cartridge part. The tape guiding pin clasp engages with and secures together the at least one side wall of the lower cartridge part and the at least one side wall of the upper cartridge part.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a National Stage Application of International Application No. PCT/EP01/05308, filed May 10, 2001. Further, the present application claims priority under 35 U.S.C. §119 of German Patent Application No. DE 100 23 854.8 filed on May 16, 2000. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a cartridge for data recording media in tape form, in particular a single-reel cartridge. 
     2. Discussion of Background Information 
     As can be seen from FIGS. 1 to  3 , cartridges for data recording media in tape form, in particular single-reel cartridges, essentially comprise a housing, that is formed by a lower housing part  701  and an upper housing part  702 . These housings are screwed to each other. A reel  30  is rotatably mounted in the housing and has a magnetic tape wound up on it (not shown). A free end is connected to a tape guiding pin  50 . The pin is fixed by means of a tape guiding pin clasp  40  in housing recesses  709  of the lower cartridge part  701  and of the upper cartridge part  702  which are located in the region of the tape exit opening. The tape exit opening is located in a corner of the housing and is capable of being closed by a spring- loaded sliding door  60 . 
     A cartridge of the generic type, or components of it, such as for example the spring- loaded sliding door of the tape exit opening, the reel brake and the leader pin clasp, are, for example, the subject of the applications EP 0 924 702 A1 and EP 0 926 675 A1. 
     For satisfactory functioning of the tape guiding pin gripper on the equipment side, a closely toleranced retaining force is required for the tape guiding pin  50 . Furthermore, the tape guiding pin  50  is to consist of non-magnetic and stainless metal. As a result of this requirement, the applicant regards the use of stainless steel to be unfavorable for the tape guiding pin clasp  40  and tape guiding pin  50 . Use of the stainless steel/stainless steel material pairing is unfavorable to the extent that it has a tendency to “seize” and consequently, during the course of use, the defined retaining force for the tape guiding pin  50  exceeds the permissible tolerance on account of changing frictional conditions. To be regarded as a further factor with adverse effects on the required constant retaining force are the production-related tolerances, which have a disproportionate effect in the case of tape guiding pin clasps of this size that are produced from spring steel wire or spring sheet metal. 
     As already mentioned at the beginning, a cartridge with screwed housing halves is concerned here. This type of connection for the housing halves appears to the applicant to be favorable insofar as, in the case of repair, it offers the user an advantage with respect to access to the data stored in the cartridge that is not be underestimated. For example, if a cartridge with welded housing halves is damaged by the use of force so severely that it can no longer be loaded in the drive, the stored data are usually also lost, since prizing open the welded cartridge entails considerable risks for the data stored on the data medium in tape form contained in it. In contrast, a cartridge with a screwed housing can be opened without any problem, and the roll of tape with the stored data can easily be removed if need be and placed into an undamaged cartridge housing. 
     However, set against this advantage is the not insignificant disadvantage that, in at least one region, the position of the screwed connection cannot be optimally chosen. For system-related reasons, no screwed connection can be provided within the region of the area A represented in FIG. 1 due to the gripper used for the tape guiding pin  50  and the required free running-out space for the data recording medium in tape form. This has the consequence that the screwed cartridge does not meet the requirements of a standardized drop test, in which the cartridge is subjected to a free drop from approximately 1 meter. 
     As the tests conducted by the applicant show, the separating joint  720  between the lower housing part  701  and the upper housing part  702  of the cartridge side walls  711  and  712  lying in the running-out direction of the tape tends to gape apart, with the housing halves changing their predetermined position in relation to each other, both horizontally and vertically, in this region. Consequently, the tape guiding pin  50  can both assume a position deviating from its predetermined position of rest, or become jammed, and it can also spring out of its arrestment. The tape guiding pin  50  can, in this cases no longer be taken up by the gripper on the equipment side, of the tape guiding device. As a result, the cartridge consequently cannot function. 
     The prior art and these considerations therefore gave rise to the object of eliminating the disadvantages described of the inconstant retaining force on the cartridge side for the tape guiding pin  50  and its inadequate positional fixing under the stress occurring when the cartridge is dropped. 
     SUMMARY OF THE INVENTION 
     The invention therefore provides for a cartridge of the type stated at the beginning that is provided with a tape guiding pin clasp and which includes a clasp additionally having a mechanism which fixes the cartridge side walls of the housing lower part and of the housing upper part, lying in the running-out direction of the tape, in a positively engaging manner and with effect in the horizontal and vertical directions. 
     The invention therefore provides for a cartridge having a housing which includes a lower cartridge part and an upper cartridge part. The lower cartridge part and an upper cartridge part are connected together. Each of the lower cartridge part and the upper cartridge part include side walls and a recess which is adapted to receive a tape guiding pin. A reel is rotatably mounted in the housing. A tape guiding pin clasp fixes the tape guiding pin in the recesses of the lower cartridge part and the upper cartridge part. The tape guiding pin is located in a region of a tape exit opening that is located in a corner of the housing. The tape exit opening is adapted to be closed by a sliding door. The tape guiding pin clasp includes a mechanism that fixes at least one side wall of the lower cartridge part to at least one side wall of the upper cartridge part. The tape guiding pin clasp engages with and fixes together the at least one side wall of the lower cartridge part and the at least one side wall of the upper cartridge part. 
     The cartridge may be of the type for data recording media in tape form. The cartridge may be of the single-reel type. The lower cartridge part and an upper cartridge part may be connected together with screws. The reel may comprise wound magnetic tape. The tape guiding pin clasp may comprise two spring elements and a retaining plate portion. The tape guiding pin clasp may positively engage with and fix together the at least one side wall of the lower cartridge part and the at least one side wall of the upper cartridge part in both a horizontal direction and a vertical direction. The tape guiding pin clasp may engage with and fix together the at least one side wall of the lower cartridge part and the at least one side wall of the upper cartridge part via at least two clip connections. The mechanism that fixes the at least one side wall of the lower cartridge part to the at least one side wall of the upper cartridge part may comprise two clips. Each of the two clips may be coupled to a retaining plate of the tape guiding pin clasp. Each of the two clips may engage in a corresponding recess in each of the at least one side walls. The tape guiding pin clasp may be arranged in a dovetail guide of the housing. The tape guiding pin clasp may comprise bevels which engage the dovetail guide. The tape guiding pin clasp may comprise bevels. The tape guiding pin clasp may comprise bevels and guiding surfaces formed by the bevels. The tape guiding pin clasp may comprise at least one arresting portion. An overall height of the at least one arresting portion may correspond to a height of a clamping portion of the tape guiding pin. The tape guiding pin clasp may comprise two arresting portions. The tape guiding pin clasp may comprise at least one spring arm. The tape guiding pin clasp may comprise a plastic material. The plastic material may comprise a high-grade moldable plastic. The high-grade moldable plastic may comprise one of a polycarbonate, a polyamide and a polyoxymethylene, as a base material. The high-grade moldable plastic may comprise at least one of fillers and functional additives. The tape guiding pin clasp may comprise carbon-fiber-reinforced polyoxymethylene with polytetrafluoroethylene. 
     The invention also provides for a cartridge comprising a housing which includes a lower cartridge part and an upper cartridge part. Each of the lower cartridge part and the upper cartridge part comprise side walls and a recess which is adapted to receive a pin. A pin clasp has two spring arms adapted to retain the pin in the recesses of the lower cartridge part and the upper cartridge part. The pin clasp comprises a first engaging clip portion that engages the at least one side wall of the lower cartridge part and a second engaging clip portion that engages the at least one side wall of the upper cartridge part. The pin clasp secures together the at least one side wall of the lower cartridge part and the at least one side wall of the upper cartridge part. 
     The invention also provides a magnetic tape cartridge comprising a housing which includes a lower cartridge part and an upper cartridge part. Each of the lower cartridge part and the upper cartridge part comprises side walls and a recess which is adapted to receive a pin. A plastic pin clasp has two spring arms adapted to retain the pin in the recesses of the lower cartridge part and the upper cartridge part. The plastic pin clasp comprises a first engaging clip portion that engages the at least one side wall of the lower cartridge part and a second engaging clip portion that engages the at least one side wall of the upper cartridge part. The plastic pin clasp secures together the at least one side wall of the lower cartridge part and the at least one side wall of the upper cartridge part. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention is now explained in more detail with reference to the drawings, in which specifically: 
     FIG. 1 shows a schematic plan view of a housing lower part of a cartridge according to the prior art; 
     FIG. 2 shows a vertical section through the region of the tape exit opening of a cartridge according to the prior art; 
     FIG. 3 shows a side view in the direction of the tape exit opening of the region represented in FIG. 2; 
     FIG. 4 shows a perspective representation of a first embodiment of a tape guiding pin clasp according to the invention; 
     FIG. 5 shows a perspective representation of a second embodiment of a tape guiding pin clasp according to the invention; 
     FIG. 6 shows a perspective representation of a third embodiment of a tape guiding pin clasp according to the invention; 
     FIG. 7 shows a perspective representation of a fourth embodiment of a tape guiding pin clasp according to the invention; 
     FIG. 8 shows a partial plan view of the region of the tape exit opening of the first embodiment of a cartridge according to the invention; 
     FIG. 9 shows a vertical section through the region of the tape exit opening of the first embodiment of a cartridge according to the invention; 
     FIG. 10 shows a partial plan view of the region of the tape exit opening of the second embodiment of a cartridge according to the invention; and 
     FIG. 11 shows a perspective representation of part of a cartridge according to the invention with a fitted tape guiding pin clasp according to embodiment 2. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A first embodiment of the tape guiding pin clasp  40   a  will now be described with reference to FIG. 4, FIG.  8  and FIG.  9 . 
     As shown in FIG. 9, the positively engaging fixing, with effect in the horizontal and vertical directions, of the cartridge side walls  711  and  712 , lying in the running-out direction of the tape in relation to each other, takes place by way of at least two clip connections  730  and with the clips  403   a . These clips  403   a  are integrated into the retaining plate  401   a  of the tape guiding pin clasp  40   a  and are capable of engaging with corresponding recesses  713  and  714  of the cartridge side walls  711  and  712 . 
     As can be seen from FIG. 4, the tape guiding pin clasp  40   a  is symmetrically formed with respect to the horizontal center line H and essentially comprises the retaining plate  401   a . The side of the retaining plate facing the reel 30 is preferably planar while the opposite side is beveled, starting from the horizontal center line H, i.e., in the direction of the two end faces in a way corresponding to the contour of the receiving pockets  721 ,  722  located in the cartridge side walls  711 ,  712 . Two spring elements  410   a  are formed on the end faces  404   a  of the retaining plate  401   a . These spring elements  410   a  essentially comprise an arcuate, offset fastening portion  411   a  and the spring arm  412   a . The respective free end of each arm  412   a  is adjoined by the arresting portion  414   a , each being formed with the contact surface  415   a . The contact surface  415   a  is, with respect to the tape guiding pin  50  of an at least partially cylindrical form. The spring element  410   a  preferably has a rectangular cross section. Other cross-sectional shapes are likewise possible, it also being possible for the individual portions of the spring element  410   a  to have different cross sections in a way corresponding to the materials selected for the tape guiding pin clasp  40   a . The outwardly facing planar surface  416   a  of the arresting portion  414   a  rises up in a step-shaped manner above the outwardly facing planar surface  413   a  of the spring arm  412   a  in order, on the one hand to, compensate for the production-related vertical tolerances, which have an effect during the assembly of the cartridge parts, and, on the other hand, to ensure that the retaining force for the tape guiding pin  50  is not adversely influenced by additional friction, based on undesirable contact of the spring arm  410   a  with the corresponding housing surface. The overall height h of the arresting portion  414   a  corresponds to the height of the clamping portion  503  (see FIG. 3) of the tape guiding pin  50 . 
     The retaining plate  401   a  has, with respect to the horizontal center line H and with respect to the vertical center line V, a symmetrical essentially H-shaped recess. The free ends of the remaining central tabs  402   a  are formed as clips  403   a  which engage in corresponding recesses  713  and  714  of the cartridge side walls  711  and  712  when the tape guiding pin clasp  40   a  is inserted into the cartridge housing. The H-shaped recess and the thickness of the retaining plate  401   a  are formed in such a way that, on the one hand, the resultant dimensions of the clips  403   a  ensure a sufficiently stable clip connection  730  with the cartridge side walls  711  and  712  and, on the other hand, no deforming or deformation of the retaining plate  401   a  and of the cartridge side walls  711  and  712  occurs. 
     The longitudinal sides of the retaining plate  401   a  have tapering mounting bevels  418   a  and  419   a  which run from the horizontal center line H in the direction of the end faces and are additionally formed as dovetails, so that, in interaction with the bevels  715  and  716  (see e.g., FIG. 11) provided in the cartridge side walls  711  and  712 , a dovetail guide is produced, through which the forces arising when the tape guiding pin  50  is moved in and out are introduced into the cartridge side walls  711  and  712 . 
     A particularly preferred embodiment of the dovetail guide is obtained if the guiding surfaces formed by the bevels  418   a  and facing in the direction of the fastening portion  411   a  preferably provide support over their full surface area and the guiding surfaces formed by the bevels  419   a , and facing in the direction of the arresting portion  414   a  preferably provide only partial support. This is achieved, for example, by the mounting bevels  419   a  facing in the direction of the arresting portion  414   a  being partially set back, so that only supporting subsurfaces remain in a restricted region above and below the horizontal center line H. This compensates for production-related tolerances and the tape guiding pin clasp  40   a  can be mounted in the cartridge housing without any play or significant stress. 
     As can also be seen from FIG. 8, the respective recesses  726   a ,  727   a  provided in the lower cartridge part  701  and in the upper cartridge part  702 , for receiving the spring arms  410   a , are formed in such a way that the spring arm in the unloaded state, that is when the tape guiding pin  50  is in the position of rest in the cartridge housing or in the operating position outside the cartridge housing, bears against the projections  724   a ,  725   a . The projection  724   a  is located in the lower housing part  701  and the projection  725   a  is located in the upper housing part  702 . This arrangement, together with the dimensions of the arresting portion  414   a , achieves the effect that, after the tape guiding pin clasp  40   a  has been fitted into the housing halves  701 ,  702 , the spring arms  412   a  are under slight prestress. On the other hand, the tape guiding pin  50  does not induce any additional stress in the spring arms  412   a  when it is in the position of rest in the cartridge housing. This means that the retaining forces only act on the spring arms  412   a  during the operation of moving the tape guiding pin  50  in and out, and a more prolonged constancy of the retaining force is achieved as a result. A preferred second embodiment of the tape guiding pin clasp  40   b  will now described with reference to FIG. 5, FIG.  10  and FIG.  11 . 
     As can be seen from FIG. 5, the second embodiment of the tape guiding pin clasp  40   b  is likewise formed symmetrically with respect to the horizontal center line H, with the retaining plate  401   b  corresponding in all design details to the retaining plate  401   a  of the first embodiment. This applies in particular to the preferred embodiment of the dovetail guide, here the guiding surfaces formed by the bevels  418   b  and facing in the direction of the supporting portion  420   b  providing support over their fill surface area and the guiding surfaces formed by the bevels  419   b  and facing in the direction of the arresting portion  414   b  providing only partial support. The reference numbers equivalent to the first embodiment and not explained any further here are identified by an appended “b”, as used generally in the description of the second embodiment. 
     The spring element  410   b  itself is subdivided into the supporting arm  420   b  and the spring arm  412   b , with the spring arm  412   b  again being adjoined by the arresting portion  414   b . The contact surface  415   b  of the latter with respect to the tape guiding pin  50  is of a convex form, and the spring element  410   b  is articulated on the retaining plate  401   b  between the supporting arm  420   b  and the spring arm  412   b  by way of the fastening portion  411   b . The spring element  412   b  preferably has a rectangular cross section. In the embodiment shown here, the fastening portion  411   b  is located approximately at the center of the spring element  410   b , but both the position of the fastening portion  411   b  and the cross section of the spring arm  412   b  can be varied in consideration of the respective conditions. 
     As already described in the first embodiment, here, too, the outwardly facing planar surface  416   b  of the arresting portion  414   b  rises up in a step-shaped manner above the outwardly facing planar surfaces  413   b  of the spring arm  412   b . A similar step-shaped elevation  422   b  is provided on the free end of the supporting arm  421   b  in a way corresponding to the requirements of the spring element  410   b , in order, on the one hand, to restrict the production-related vertical tolerances, which have an effect during the assembly of the cartridge parts, and on the other hand, to ensure that the retaining force for the tape guiding pin  50  is not adversely influenced by additional friction, based on undesirable contact of the spring arm  410   b  with the corresponding surface of the housing recess  726   b ,  727   b . Both the overall height h of the arresting portion  414   b  and the overall height of the supporting arm  421   b , including the stepped elevation  422   b  provided at its free end, correspond to the height of the clamping portion  503  of the tape guiding pin  50 . 
     As can also be seen from FIG. 10, the clearance  726   b ,  727   b  provided in the lower cartridge part  701  and upper cartridge part  702 , for receiving the spring arm  410   b , is formed in such a way that the spring arm in the unloaded state, that is when the tape guiding pin  50  is in the position of rest in the cartridge housing or in the operating position outside the cartridge housing, bears against the projections  724   b ,  725   b ,  728   b  and  729   b , with the projections  724   b  and  728   b  being located in the lower housing part  701  and the projections  725   b  and  729   b  being located in the upper housing part  702 . This arrangement, together with the dimensions of the arresting portion  414   b , achieves the effect that, after the tape guiding pin clasp  40   b  has been fitted into the housing halves  701 ,  702 , the spring arms  412   b  are under slight prestress, but the tape guiding pin  50  does not induce any additional stress in the spring arms  412   b  of the tape guiding pin clasp  40   b  when it is in the position of rest in the cartridge housing. This again means that the retaining forces only act on the spring arms  412   b  during the operation of moving the tape guiding pin  50  in and out, and a more prolonged constancy of the retaining force is achieved as a result. 
     A further advantage of this described embodiment is consequently that the forces arising during the moving in and out of the tape guiding pin  50  are introduced into the bottom of the cartridge and the top of the cartridge via the resting surfaces of the projections  724   b ,  725   b ,  728   b  and  729   b , and consequently do not act on the dovetail guide. Furthermore, no relative movement between the supporting arm  420   b , the lower part of the cartridge  701  and the upper part of the cartridge  702  is produced in the region of the bearing surfaces of the projections  724   b ,  725   b ,  728   b  and  729   b , and consequently no quality-reducing abrasion occurs at this location. 
     As already mentioned at the beginning, the tape guiding pin gripper/tape guide system, which guides the data medium in tape form to the take-up reel of the drive, imposes high requirements on the tape guiding pin clasp  40   a ,  40   b ,  40   c  and  40   d . Of particular significance here are both the dimensional accuracy, while maintaining smallest possible production tolerances, and the material used. While the dimensional accuracy is ensured by using the precision injection-molding process, with respect to the selection of the material to be used it is necessary to ensure a high modulus of elasticity and adequate lubricity, to prevent inadmissible fluctuations in the retaining force due to diminishing of the resilient force and also due to changing frictional conditions in the region of the contact surfaces of the tape guiding pin and tape guiding pin clasp. 
     High-grade moldable plastics are suitable as the material for the tape guiding pin clasp  40   a ,  40   b ,  40   c  and  40   d , high-grade being understood to mean plastics with a high modulus of elasticity and good wear resistance. Thermoplastics, elastomers and thermosetting plastics are suitable as base materials. Examples of preferred materials which can be used are polycarbonate (PC), polyamide (PA) and polyoxymethylene (POM), it also being possible for the base materials to be provided with fillers or functional additives. Both organic and inorganic substances are suitable as fillers, taking the form of particles, for example as fibers or spheres. 
     Carbon-fiber-reinforced polyoxymethylene is particularly preferred, the lubricity being ensured by the addition of polytetrafluoroethylene. 
     A material which meets these requirements is obtainable for example under the designation KCL-4022D from the company LNP Engineering Plastics Inc. This material is based on polyoxymethylene, contains 10% carbon fiber and 10% polytetrafluoroethylene and has a modulus of elasticity of 7 300 Mpa. 
     To obtain both a reliably acting clip connection  730  and a functionally capable dovetail guide, the wall thickness of the cartridge side walls  711 ,  712 , lying in the running-out direction of the tape, of the lower housing part  701  and the housing upper part  702  is preferably to be increased in the corresponding region, in particular in the region of the bevels ( 715 ,  717  in the lower housing part and  716 ,  718  in the upper housing part—not shown) to the extent permitted by the run-out of the tape. 
     As FIG. 9 also reveals, for simple release of the clip connection  730 , it is expedient to provide in the cartridge side walls  711  and  712 , in the region of the clip connections  730 , a respective bore  733 , through which the clip  403   a  and  403   b  is pressed by way of a suitable pin (not shown) out of the corresponding recess  713 ,  714  of the cartridge side walls  711  and  712 . 
     The third tape guiding pin clasp  40   c  shown in FIG. 6, represents variation of the tape guiding pin clasp  40   b  depicted in FIG. 5 that has been optimized from technical injection-molding aspects. The retaining plate  401   c  is shown here as having only a slot-shaped recess  409   c  instead of the H-shaped recess. The reference numbers equivalent to the second embodiment and not explained any further here are identified by an appended “c”. 
     Finally, represented in FIG. 7 is a further material-optimized variant of the tape guiding pin clasp  40   d , with the retaining plate now only comprising a cross-piece  401   d  which connects the two spring arms  410   d  to each other. Provided on the cross-piece are both the two clips  403   d  for connecting the upper housing part  701  and the lower housing part  702  and the two butt straps  417   d  for fixing the tape guiding pin clasp  40   d  in the housing halves. 
     Use of the tape guiding pin clasps according to the invention that are represented is not restricted to, screwed cartridge housing they can also be used advantageously in the case of cartridge housing halves that are welded to each other.