Abstract:
A system for opening and closing a resealable cartridge having a tray and a flexible cover resealably engaged with the tray. The system comprises: a base for receiving the tray of the cartridge; a roller shaft having means for engaging the cover of the cartridge; positioning means operably connected to the roller shaft to affect positioning of the roller shaft relative to the cartridge between a first position wherein the roller shaft is spaced from the cartridge and a second position different from the first position wherein the roller shaft is not spaced from the cartridge; and a motor for rotating the roller shaft in a first rotational direction to wind the cover about the roller shaft, thereby removing at least a portion of the cover from the tray, and for rotating the roller shaft in a second rotational direction to unwind the cover from the roller shaft thereby resealably engaging the cover with the tray.

Description:
FIELD OF THE INVENTION  
       [0001]     The invention relates generally to resealable cartridges, and more particularly, to a system for opening and closing a resealable cartridge.  
       BACKGROUND OF THE INVENTION  
       [0002]     Resealable cartridges have been employed in various applications for transporting articles. Such resealable cartridges are desirable features, including preventing exposure of the transported articles to environmental elements. For example, laser imaging machines use resealable cartridges to transport photosensitive media, such as x-ray and other types of medical imaging photographic film, since it is sometimes necessary to load a laser imaging machine with a different type or size of photosensitive media. Such laser imaging machines are well known in the art for forming an image by scanning a modulated laser beam across the photosensitive media. Prior to the formation of the image, a cartridge containing one or more photosensitive media is loaded into the laser imaging machine. The cartridge includes a tray having a supply area for containing the photosensitive media, a media access opening, and a flexible cover adhesively attached to tray to extend over the media access opening to form a light-tight seal of the cartridge. The light-tight seal enables the cartridge to be transported in light conditions that would otherwise cause exposure of the photosensitive media within the cartridge. U.S. Pat. No. 5,132,724 (Lemberger), U.S. Pat. No. 5,473,400 (Lemberger), and U.S. Pat. No. 5,480,134 (Weber) show examples of a resealable cartridge, each of these being incorporated herein by reference.  
         [0003]     The interior of a laser imaging machine provides a light-tight environment. To carry out an imaging operation, the laser imaging machine withdraws one or more photosensitive media from the access opening of the cartridge. Therefore, the laser imaging machine requires a system that can open the cartridge within the laser imaging machine to allow withdrawal of the photosensitive media from the access opening, and close/reseal the cartridge within the laser imaging machine to effect the light-light seal. In the ordinary course of use, the cartridge must be opened and closed several times.  
         [0004]     U.S. Pat. No. 5,132,724 (Lemberger) and U.S. Pat. No. 5,480,134 (Weber) show examples of mechanisms for opening and closing a resealable media cartridge. While such systems may have achieved certain degrees of success in their particular applications, they employ a relatively complicated mechanism that can be expensive to manufacture and have other disadvantages.  
         [0005]     Accordingly, there is a need for a system which is capable of reliably performing the opening/closing functions, commercially viable, reduced in size, provides good resealing, and efficiently manufacturable.  
         [0006]     The present invention provides a system for opening and closing a resealable cartridge which is capable of reliably performing the opening/closing functions, commercially viable, reduced in size, provides good resealing, and efficiently manufacturable.  
         [0007]     In addition, wrinkles in the cartridge cover can occur while closing, and such wrinkles can decrease the usable life of the cartridge. In addition to wrinkles, laser imaging machines which use high sealing forces tend to displace the cover adhesive. The present invention increases the usable life of the cartridge by reducing/eliminating both wrinkles and displaced cover adhesive.  
         [0008]     Additional features and advantages of the present invention will be set forth in part in the description that follows, and in part will be apparent from the description, or may be learned by practice of the invention. The advantages of the invention will be realized and attained by the system particularly pointed out in the written description and claims thereof, as well as in the appended drawings.  
       SUMMARY OF THE INVENTION  
       [0009]     An object of the present invention is to provide a system for opening and closing a resealable cartridge.  
         [0010]     Another object of the present invention is to provide such a system which is capable of reliably performing the opening/closing functions.  
         [0011]     A further object of the present invention is to provide such a system which is commercially viable, reduced in size, provides good resealing, and efficiently manufacturable.  
         [0012]     These objects are given only by way of illustrative example, and such objects may be exemplary of one or more embodiments of the invention. Other desirable objectives and advantages inherently achieved by the disclosed invention may occur or become apparent to those skilled in the art. The invention is defined by the appended claims.  
         [0013]     According to one aspect of the invention, there is provided a system for opening and closing a resealable cartridge having a tray and a flexible cover resealably engaged with the tray. The system comprises: a base for receiving the tray of the cartridge; a roller shaft having means for engaging the cover of the cartridge; positioning means operably connected to the roller shaft to affect positioning of the roller shaft relative to the cartridge between a first position wherein the roller shaft is spaced from the cartridge and a second position different from the first position wherein the roller shaft is not spaced from the cartridge; and a motor for rotating the roller shaft in a first rotational direction to wind the cover about the roller shaft, thereby removing at least a portion of the cover from the tray, and for rotating the roller shaft in a second rotational direction to unwind the cover from the roller shaft thereby resealably engaging the cover with the tray. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]     The foregoing and other objects, features, and advantages of the invention will be apparent from the following more particular description of the preferred embodiments of the invention, as illustrated in the accompanying drawings.  
         [0015]      FIG. 1  shows an exemplary laser imaging machine configured for use with a resealable cartridge, and suitable for incorporation of an opening and closing system in accordance with the present invention.  
         [0016]      FIG. 2  shows an isometric view of a prior art resealable cartridge with the cover removed.  
         [0017]      FIG. 3  shows a top view of the prior art cartridge of  FIG. 2  with a portion of the cover removed.  
         [0018]      FIG. 4  shows a side view of the cartridge shown in  FIG. 2 .  
         [0019]      FIG. 5  shows an isometric view of the opening and closing system of the present invention for opening and closing the cartridge shown in  FIG. 2 .  
         [0020]      FIG. 6  shows a view of a roller shaft forming part of the opening and closing system of  FIG. 5 , in accordance with the present invention.  
         [0021]      FIG. 7  shows a side view of the opening and closing system shown in  FIG. 5   
         [0022]      FIG. 8  shows a rear partial view of the spring assembly which provides a sealing force.  
         [0023]      FIGS. 9   a  and  9   b  show the formation of a wrinkle in the cover which can occur during operation of the opening and closing system of the present invention.  
         [0024]      FIG. 10  shows a bottom isometric view of the opening and closing system shown in  FIG. 5  showing the constant force springs used to reduce/eliminate wrinkles.  
         [0025]      FIG. 11  shows an isometric view of the opening and closing system of the present invention disposed within a drawer of a laser imaging machine illustrating a first loading arrangement.  
         [0026]      FIG. 12  shows an isometric view of the opening and closing system of the present invention illustrating a second loading arrangement.  
         [0027]      FIG. 13  shows a partial side view of the opening and closing system of the present invention in a first position referred to as the home position.  
         [0028]      FIG. 14  shows a partial side view of the opening and closing system of the present invention in a second position referred to as the cam lift position.  
         [0029]      FIG. 15  shows a partial side view of the opening and closing system of the present invention in a third position referred to as the cam dwell position.  
         [0030]      FIG. 16  shows a partial side view of the opening and closing system of the present invention in a fourth position referred to as the cover engaged position.  
         [0031]      FIG. 17  shows a partial side view of the opening and closing system of the present invention in a fifth position referred to as the open position. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0032]     The following is a detailed description of the preferred embodiments of the invention, reference being made to the drawings in which the same reference numerals identify the same elements of structure in each of the several figures.  
         [0033]      FIG. 1  shows an exemplary laser imaging machine  10  configured for use with a resealable cartridge, and suitable for incorporation of an opening and closing system in accordance with the present invention. Machine  10  can include a hinged loading door  14  into which a resealable cartridge can be loaded for imaging operations. Other suitable laser imaging machines can employ a loading drawer that slides out to receive the cartridge. Other loading arrangements may be known to those skilled in the art.  
         [0034]     The cartridge opening/closing system of the present invention is mounted within laser imaging machine  10 . After the cartridge has been loaded within laser imaging machine  10 , the door/drawer is closed to seal the cartridge within the light-tight environment of laser imaging machine  10 . The opening/closing system then operates to open the cartridge to permit access to the photosensitive media in the cartridge. The photosensitive media is withdrawn from the opened cartridge by imaging hardware associated with machine  10 . The media is then imaged by other subsystems of laser imaging machine  10 . The opening/closing system is also actuated to close the cartridge before the cartridge is removed from laser imaging machine  10 . Since the cartridge is resealable, it can be removed from machine  10  before all the photosensitive media within the cartridge has been exposed. Cartridges with different sizes or types of media can therefore be conveniently loaded/reloaded into and removed from laser imaging machine  10  as needed, and without wasting any unused media remaining within the cartridge.  
         [0035]     Laser imaging machine  10  may include more than one drawer so that more than one cartridge can be loaded into machine  10 . This may be desirable if the cartridges contain photosensitive media of different sizes. As such, it is noted that the opening/closing system needs to be configured to operate with cartridges containing photosensitive media of different sizes An exemplary resealable cartridge  12  is described with reference to  FIGS. 2 through 4 . Other configurations may be known to those skilled in the art. Since resealable cartridges are well-known, the cartridge will not be discussed in detail.  
         [0036]     Cartridge  12  includes an optically opaque media-receiving tray  20  and a flexible, optically opaque cover  22 . The flexible cover  22  can be resealably mounted to tray  20  by an adhesive material  24 , by means of magnetics, or other method known to those skilled in the art. For ease of explanation of the present invention, cover  22  is mounted by means of adhesive  24 . Tray  20  can be molded in one piece from a photo-inert, polyolefin material. Tray  20  includes a bottom wall  26 , a front wall  28 A, a rear wall  28 B, opposite side walls  28 C,  28 D, and a lip having sections  30 A- 30 D extending outward from upper edges of walls  28 A- 28 D, respectively, around a periphery of the tray. Adhesive material  24  may take the form of segments of adhesive disposed at intervals along lip sections  30 A- 30 D, or a one-piece adhesive gasket applied to the lip. Side walls  28 A- 28 D and lip sections  30 A- 30 D define an access opening. For laser imaging, the access opening may contain one or more photosensitive media  31 , as shown in  FIG. 2 . Photosensitive media  31  may comprise, for example, x-ray film, photosensitive film, photosensitive paper, or other photosensitive substrate materials for imaging applications.  
         [0037]     Tray  20  includes inward projecting guides  32  formed on walls  28 A- 28 D for properly positioning photosensitive media  31 . Feet  34 A- 34 D are formed into and extend downward from bottom wall  26  to support cartridge  12  within base  18  of the opening and closing mechanism in accordance with the present invention. A media presence monitoring well  35  also is formed in bottom wall  26 . A media presence monitoring sensor associated with laser imaging machine  10  extends into well  35  below the surface of bottom wall  26  when all media have been removed from tray  20 , thereby detecting that tray  20  is empty. Bottom wall  26  further includes positioning recesses  36 , molded into feet  34 A and  34 B, that extend upward into tray  20  from the exterior surface of the bottom wall.  
         [0038]     Feet  34 A,  34 B formed adjacent front wall  28 A include ramp surfaces  38  that slope downward from the lower edge of the front wall, as shown in  FIG. 4 . Ramp surfaces  38  can be employed to guide feet  34 A,  34 B over optional locator pins formed in base  18  when cartridge  12  is loaded into the base. Tray  20  further includes a recessed area  40  formed in bottom wall  26  that provides a platform on the exterior surface of the bottom wall. The platform formed by recessed area  40  can carry bar code indicia for identifying the type of media contained in cartridge  12 .  
         [0039]     With reference to  FIGS. 2 and 3 , a series of evenly spaced cut-out sections  42  are formed in lip section  30 A over the top edge of front wall  28 A. Cut-out sections  42  define a series of spaced projections  44  on lip section  30 A. A forward area  45  of cover  22  includes a series of elongated apertures  46  aligned with cut-out sections  42  of tray  20  when the cover is disposed over the tray. The cut-out sections  42  cooperate with apertures  46  to facilitate engagement of cover  22  by the opening and closing mechanism of the present invention.  
         [0040]     Cover  22  is preferably a flexible, photo-inert and optically opaque sheet of material sized to extend over the media access opening of tray  20  and mate with lip sections  30 A- 30 D. The cover  22  comprises a material that is preferably stretchable enough to avoid pulling away from tray  20  when cartridge  12  is flexed, but rigid enough to resist excessive stretching during opening and closing operations. Cover  22  may also include a reinforcing strip (not shown) at a forward area  45  to increase the rigidity of the cover in the area above cut-out sections  42  of tray  20 . The reinforcing strip is intended to resist tearing of apertures  46  during engagement with the opening and closing mechanism. The stretch- resistant material and reinforcing strip of cover  22  are designed to resist the damage caused by certain forces applied to the cover during the opening and closing operations, and thus address the effects of such forces in an effort to extend cartridge life.  
         [0041]     The opening and closing system of the present invention is intended to reduce/eliminate the application of the forces responsible for stretching cover  22  and tearing apertures  46 , thereby addressing the source of such problems. An exemplary embodiment of the opening and closing mechanism of the present invention will now be described in detail with reference to  FIGS. 5-17 .  
         [0042]     Referring first to  FIGS. 5-8 , an opening and closing system  50  includes a base  52  for receiving and supporting resealable cartridge  12 , a roller shaft  54  including means for engaging cover  22 , a motor  56  for rotating roller shaft  54 , and a carriage  58 , slidably coupled to base  52 , for supporting roller shaft  54  and motor  56 . Carriage  58  can be mounted on drawer slides.  
         [0043]     Generally, the purpose of opening and closing system  50  is to open and close cover  22  of cartridge  12 . Roller shaft  54  rotates and spins along the front edge cartridge  12  until projections/teeth on roller shaft  54  engage apertures  46  in cover  22 . Once engaged, roller shaft  54  rolls up onto the front and back walls of cartridge  12  (moving along the length of cartridge  12  in the direction shown by arrow A in  FIG. 5 ), thereby wrapping cover  22  around/about the diameter of roller shaft  54 . As the motorized roller shaft turns, it moves towards the center of cartridge  12  until cover  22  is open sufficiently to allow a mechanism or other device to remove the media from cartridge  12 . Operating roller shaft  54  in the opposite direction reseals cartridge  12 .  
         [0044]     More particularly, a rotation of roller shaft  54  in the first (opening) direction generates tractional force between roller shaft  54  and cartridge  12 . A bias means applies a normal force that biases roller shaft  54  downward against cartridge  12 . The carriage includes means for supporting roller shaft  54  and motor  56 , as will be described. The tractional force results in a translational force that drives the carriage to slide along tray  20 . A tractional force generated between roller shaft  54  and cover  22  during the closing operation similarly provides a translational force that drives the carriage to slide.  
         [0045]     Roller shaft  54  is an elongated member, and can be formed of steel. A cut-out, winding section  78 , extending along a central longitudinal axis, includes means for engaging apertures  46  in cover  22  to open and close cartridge  12 . As shown in  FIG. 6 , winding section  78  has a substantially semi-circular cross-section. In the embodiment shown, the cover engaging means of roller shaft  54  comprises an elongated, rectangular plate  80  having a plurality of indentations  82  defining curved, tooth-like projections  84 . Projections  84  preferably are sized and spaced to fit within apertures  46  of cover  22 , as well as cut-out sections  42 , when roller shaft  54  is rotated downward toward base  18 . Plate  80  and projections  84  may be constructed by stamping them out of a piece of sheet metal, and fastening them with screws  86  to a portion of winding section  78  that has been cut down to approximately a half diameter. The radius of curvature of projections  84  can be achieved by bending the plate  80  about a metal form.  
         [0046]     A spring assembly  60  is disposed at each end of roller shaft  54  to provide a sealing force. As best shown in  FIG. 8 , spring assembly  60  includes a pinch roller  62  attached to a bracket  64  that pivots about a shaft  66  attached to a roller link  68 . A torsion spring  70  provides a torque to apply a suitable sealing force. In one embodiment of the present invention, a torque of 0.66 inch-pounds has been found to apply a suitable sealing force of 1.4 pounds.  
         [0047]     Also disposed at each end of roller shaft  54  is a cam  72  which controls the motion of roller shaft  54  and provides indexing of roller shaft  54  during engagement with cover  22 . A pair of torsion springs  74  disposed at each end of roller shaft  54  direct roller shaft  54  along a cam surface  76  of a pair of cam nests  77 , as will be more particularly described below. Pivot mechanism  75  links torsion springs  74  with roller shaft  54 . Motor  56  can be a single dc motor.  
         [0048]     High roller pressure and wrinkles in cover  20  can limit the usable life of cartridge  12 . High roller pressure displaces the cover adhesive, resulting in poor sealing characteristics, when the cartridge is open for extended periods (for example, overnight). Wrinkles occur when opening and closing system  50  is closing cartridge  12 .  FIGS. 9   a  and  9   b  illustrate a factor that leads to wrinkles.  FIG. 9   a  shows roller shaft  54  operating (moving in opening direction D) to open cover  22  wherein a portion  79 ′ of cover  22  does not conform roller shaft  54 .  FIG. 9   b  shows roller shaft  54  during the subsequent closing operation (moving in closing direction E) wherein the non-conforming portion  79 ′ of cover  22  forms on the cartridge as a wrinkle  79 ″.  
         [0049]     It was determined that adding a force in the closing direction (i.e., during the closing operation) keeps cover  22  tight/taught against roller shaft  54 , thereby eliminating non-conforming cover portions and hence the wrinkles. Referring to  FIG. 10 , a pair of constant force springs  81  supplies a force sufficient to eliminate the wrinkles without pulling cover  22  closed. The constant force springs pull carriage  12  toward a frame  83  in the closing direction. This addition force eliminates the need for a high sealing force (high forces have been used on previous opening and closing systems), and eliminates the adhesive displacement. A force of 0.50 pounds for each constant force spring (1.00 pounds total) has been found to be suitable.  
         [0050]     Referring now to  FIG. 11 , in operation, loading drawer/door  14  is opened and cartridge  12  is loaded into laser imaging machine  10  by sliding cartridge  12  onto base  52  in a direction shown by arrow B. One or more slides  85  can be employed to promote the loading/unloading of cartridge  12  in drawer/door  14 . Note the positioning of opening and closing  50  relative to the direction of loading of cartridge  12 . That is, cartridge  12  is loaded in a direction toward opening and closing system  50 . As such, a user is not exposed to projections  84  when loading.  
         [0051]      FIG. 11  provides an alternative loading arrangement. In this arrangement, cartridge  12  is loaded into laser imaging machine  10  by sliding cartridge  12  onto base  52  in a direction shown by arrow C along slide  85 . With this loading arrangement, cartridge  12  is loaded in a direction along (i.e., parallel to) the axis of roller shaft  54 . Opening and closing system  50  is disposed such that it does not interfere with the loading of cartridge  12 .  
         [0052]     One or more sensors can be employed to verify the cartridge condition (e.g., presence, absence, and/or proper orientation) of cartridge  12  within laser imaging machine  10 . These sensors can be mechanical or electrical sensors, as is well known to those skilled in the art. For example, referring to  FIG. 12 , three sensors can be employed S 1 , S 2 , S 3 , with the sensors being mechanical members. With three sensors, three situations can be determined: the absence of the cartridge, the correct placement of the cartridge, and the incorrect placement of the cartridge. The situation can be determined by the state of each sensor. For example, the following can be determined:  
                                                                                   Sensor State                Cartridge Placement   Front   Middle   Back                       None Present   Blocked   Blocked   Blocked           Correct   Unblocked   Blocked   Unblocked                Incorrect   Any Except Above                      
 
 Other relationships may be known to those skilled in the art. 
 
         [0054]     Referring again to  FIG. 11 , one sensor S 4  is employed to verify the presence and/or proper orientation of cartridge  12 . With the arrangement of  FIG. 11 , the following cartridge conditions can be determined:  
                                                   Cartridge Placement   Sensor State                           None Present   Blocked           Correct   Unblocked                      
 
         [0055]     Opening and closing system  50  can operate using one dc motor (i.e., motor  56 ) and two position sensors.  FIGS. 13-17  illustrate the operation of opening and closing system  50  to open and close cartridge  12 .  
         [0056]      FIG. 13  shows a partial side view of opening and closing system  50  in a first position, referred to as the home position. This is the position of opening and closing system  50  when cartridge  12  is loaded in laser imaging machine  10 . In this position, the components of system  50  are not disposed within the loading area of cartridge  12 . In this position, cams  72  actuate a sensor  88  indicating that roller shaft  54  is in the home position. In this position, roller shaft  54  is disposed away from the perforated edge  89  of cover  22 , and projections  84  are disposed downward, toward base  52 .  
         [0057]      FIG. 14  shows a partial side view of opening and closing system  50  in a second position, referred to as the cam lift position. In this position, each cam  72  interfaces with a surface on cam nest  77  to lift/raise roller shaft  54  towards perforated edge  89  of cover  22 .  
         [0058]      FIG. 15  shows a partial side view of opening and closing system  50  in a third position, referred to as the cam dwell position. In this position, each cam  72  interfaces with a surface on cam nest  77  in a dwell state.  
         [0059]      FIG. 16  shows a partial side view of opening and closing system  50  in a fourth position, referred to as the cover engaged position. In this position, roller shaft  54  continues to rotate and projections  84  engage apertures  46  of cover  22 .  
         [0060]      FIG. 17  shows a partial side view of opening and closing system  50  in a fifth position, referred to as the open position. In this position, an end-of-travel sensor  91  is blocked to indicate the end of the travel for opening and closing system  50 .  
         [0061]     Reversing the positions shown in  FIGS. 13-17  effects closure/sealing of cover  22  on cartridge  12 .  
         [0062]     The invention has been described in detail with particular reference to a presently preferred embodiment, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention. The presently disclosed embodiments are therefore considered in all respects to be illustrative and not restrictive. The scope of the invention is indicated by the appended claims, and all changes that come within the meaning and range of equivalents thereof are intended to be embraced therein.  
       Parts List  
       [0063]    
       
           10  laser imaging machine  
           12  resealable cartridge  
           14  hinge loading door  
           18  base  
           20  media receiving tray  
           22  flexible cover  
           24  adhesive material  
           26  bottom wall  
           28 A front wall  
           28 B rear wall  
           28 C- 28 D opposite side walls  
           30 A- 30 D lip sections  
           31  photosensitive media  
           32  projecting guides  
           34 A- 34 D feet  
           35  monitoring well  
           36  positioning recesses  
           38  ramp surfaces  
           40  recessed area  
           42  cut out sections  
           44  spaced projections  
           45  forward area  
           46  elongated apertures  
           50  opening/closing system  
           52  base  
           54  roller shaft  
           56  motor  
           58  carriage  
           60  spring assembly  
           62  pinch roller  
           64  bracket  
           66  shaft  
           68  roller link  
           70  torsion spring  
           72  cam  
           74  torsion springs  
           75  pivot mechanism  
           76  cam surface  
           77  cam nests  
           78  winding section  
           79 ′ portion  
           79 ″ wrinkle  
           80  rectangular plate  
           81  springs  
           82  indentations  
           83  frame  
           84  projections  
           85  slides  
           86  screws  
           88  sensor  
           89  perforated edge  
           91  end of travel sensor  
          S 1 -S 4  sensors