Abstract:
There is disclosed a portable thermal printer having a printer housing, a printing mechanism and an ink ribbon cartridge containing an ink ribbon cartridge containing an ink ribbon. The cartridge has a cartridge housing and an improved brake for applying a slight braking force on a core of an ink ribbon supply roll in the housing. The cartridge is easy to load onto the printer. The cartridge forms part of the printer housing and is latched thereto. The cartridge is slid onto the printer and the cartridge housing detents into position.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    This invention relates to the field of printers and ink ribbon cartridges and methods pertaining thereto.  
           [0003]    2. Brief Description of the Prior Art  
           [0004]    The following prior art is made of record: U.S. Pat. Nos. 327,495; 2,764,934; 3,774,538; 4,160,605; 4,479,730; 4,581,616; 4,609,298; 4,611,218; 4,655,623; 4,673,304; 4,685,815; 4,702,631; 4,776,714; 4,830,523; 4,832,514; 4,899,172; 4,910,602; 4,914,452; 4,915,516; 4,924,242; 4,944,619; 4,957,379; 4,970,531; 5,035,325; 5,128,763; and British patent 1,455,915.  
         SUMMARY OF THE INVENTION  
         [0005]    The invention relates to an improved, user-friendly, compact, portable, small-footprint, easy-to-use printer.  
           [0006]    A feature of the invention is an improved ink ribbon cartridge. A specific embodiment of the cartridge is comprised of a cartridge housing with a stationary shaft and a brake member on the shaft in frictional contact with an inner surface of a core of an ink ribbon roll. The brake member cooperates with the core to prevent an excessive amount of ink ribbon to be paid out during the printing operation and to maintain tension in the ink ribbon.  
           [0007]    Another feature of the invention is the new use of a tubular member as a brake member cooperating with the inner surface of a core of an ink ribbon roll.  
           [0008]    Another feature of the invention resides in an improved arrangement for coupling an ink ribbon cartridge into a printer. In a specific embodiment, the ink ribbon cartridge includes a housing with first and second housing members spaced apart to provide an opening. The print head has a line of printing elements and is mounted on a support. The cartridge is mounted onto the printer so that the support and the print head enter the opening between the housing members of the cartridge.  
           [0009]    It is another feature of the invention for the cartridge to have a flexible resilient housing wall within which the ink ribbon is based. The housing wall deflects resiliently while the cartridge is being inserted until the housing wall encounters a recess which causes the cartridge to detent essentially into its operating position.  
           [0010]    It is a feature of the invention to provide an improved arrangement for detenting a cartridge in a printer.  
           [0011]    It is a feature of the invention to provide an ink ribbon cartridge that forms part of an improved housing assembly of a printer. In a specific embodiment, a portion of the cartridge is received in the printer housing and another portion extends outside the printer housing. The print head is mounted on a support and the cartridge has an opening for receiving the support. The printer, thus, has a very compact organization.  
           [0012]    It is a feature of the invention to provide an improved housing assembly for a printer in which the printer includes a printer housing and an ink ribbon cartridge coupled to the printer housing. In a specific embodiment, the cartridge is located and latched in its operating position, preferably by a toggle mechanism.  
           [0013]    It is a another feature of the invention to provide a thermal printer operable in both thermal direct and thermal transfer modes, wherein an ink ribbon cartridge housing is effective for forming a portion of the guideway for the web to be printed upon and for providing part of the printer housing during operation in the thermal direct mode, and wherein the cartridge housing is effective additionally for supplying ink ribbon to the thermal print head during operation in the thermal transfer mode.  
           [0014]    Other features of the invention will be evident to one skilled in the art by reference to the drawings, the following description and the appended claims. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]    [0015]FIG. 1 is a perspective view of the printer of the invention;  
         [0016]    [0016]FIG. 2 is a vertical sectional view of the printer;  
         [0017]    [0017]FIG. 3 is a view similar to FIG. 2 but showing the printer in its open position and showing the ink ribbon cartridge exploded away;  
         [0018]    [0018]FIG. 4 is an exploded perspective view of a mounting section and a print head assembly mounted by the mounting section;  
         [0019]    [0019]FIG. 5 is an exploded perspective view of a housing section which mounts the mounting section of FIG. 4;  
         [0020]    [0020]FIG. 6 is an assembled view of the mounting section and print head assembly shown in FIG. 4 and the mounting section shown in FIG. 5;  
         [0021]    [0021]FIG. 7 is an exploded perspective view of an assembly for latching the ink ribbon cartridge and for guiding a carrier web of composite label web;  
         [0022]    [0022]FIG. 8 is an enlarged sectional view of the assembly shown in FIG. 7 and associated components;  
         [0023]    [0023]FIG. 9 is a fragmentary view showing the manner in which the print head is located relative to the platen;  
         [0024]    [0024]FIG. 10 is an exploded perspective view showing the drive mechanism for the printer and the ink ribbon cartridge;  
         [0025]    [0025]FIG. 11 is an exploded perspective view of the ink ribbon cartridge;  
         [0026]    [0026]FIG. 12 is an exploded rotated perspective of cartridge housing sections shown in FIG. 11;  
         [0027]    [0027]FIG. 13 is a sectional view of the cartridge showing a brake;  
         [0028]    [0028]FIG. 14 is a view showing a fragmentary portion of the cartridge and a drive spindle; and  
         [0029]    [0029]FIG. 15 is a rear elevational view of the cartridge. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0030]    With reference to FIG. 1, there is shown a printer generally indicated at  20  which includes a housing generally indicated at  21 . The printer  20  has a relatively small footprint so that its base  22  only occupies a small area on a supporting surface. The housing  21  extends generally vertically, as shown with its vertical extent being relatively long. The printer  20  can also be worn by an operator using a suitable carrying strap (not shown). The housing  21  and a housing  23  of an ink ribbon cartridge generally indicated at  24  form a housing assembly  25 .  
         [0031]    The housing mounts an on/off surface  26 , a light  27  for showing whether the printer  20  is “on” or “off”, and certain printer error conditions, and aligned recesses  28  (only one of which is shown) at opposite sides of the housing for connecting the ends of the carrying strap to the housing  21 .  
         [0032]    With reference to FIG. 2, the housing  21  is shown to removably mount a battery pack  29  containing a series of rechargeable batteries  30 . A spring-urged latch  31  releasably holds the battery pack  29  in position. The housing  21  also mounts electronic controls generally indicated at  32 .  
         [0033]    The housing  21  mounts a pair of opposed hub members  33 , only one of which is shown, for mounting a roll R of record members. The illustrated roll R is shown to be a composite web C comprised of a carrier web W and labels L releasably adhered to the carrier web W along its length. However, the roll R can alternatively be comprised of a web of tags (not shown). The housing  21  has a chamber  33 ′ which receives the roll R. The chamber  33  is comprised of opposed concave arcuate walls  34  and  35 . The wall  34  merges with a guide  36  which helps guide the composite web C (or the tag web as the case may be) from the roll R to between a print head  37  and a platen roll  38 . The housing  21  also includes mounting sections  39  and  40 . The mounting section  39  is pivotally mounted on posts  41  received in opposed holes  42 . The mounting section  39  includes the wall  35 . The mounting section  40  is pivotally connected to the mounting section  39 . The mounting section  40  has a generally vertically extending outer wall portion  43  and a shelf or generally horizontally extending portion  44 . The shelf  44  has a pair of spaced arm or support portions  44 ′ which mount the cartridge  24 . The arm portions  44 ′ are received in respective U-shaped channels  130   u  and  131   u  in the cartridge housing  23 . The channel  130   u  is comprised of ribs  130   a ,  130   b  and  130   c , and the channel  131   u  is comprised of ribs  131   a ,  131   b  and  131   c . The shelf  44  mounts a print head assembly  45 . The ink ribbon cartridge  24  is received on the printer  20  as best shown in FIG. 2. An assembly generally indicated at  46  is used to latch the housing  23  of the cartridge  24  and mounting section  40  to the housing  21  and to guide the carrier web W.  
         [0034]    As shown in FIG. 4, the mounting section  40  mounts the print head assembly  45 . The print head assembly  45  includes a plate  46  which extends generally horizontally. The plate  46  has an upturned curved plate portion  47  (FIGS. 2, 3 and  4 ) which terminates at a downwardly extending knife-shaped edge  48  (FIGS. 3 and 4).  
         [0035]    A depending guide  49  having an inverted U-shaped guide surface  50  is connected to each end of the plate  46 . An ink ribbon guide  51  is mounted to the plate portion  47 . When correctly adjusted the guide  51  causes the ink ribbon IR to track correctly. The plate portion  47  has a depending stud  52  which is received in a hole  53  in the guide  51 . The guide  51  has an integrally formed plate  54 . The guide  51  also has an L-shaped bracket  55  which is located above the upper surface of the plate  46 . An adjusting screw  57  passes through a slot  58  in the plate portion  47  and is threadably received in a threaded hole  56  in an upstanding portion  56 ′ of the bracket  55 . The screw  57  extends through a compression spring  59  which bears against the upstanding portion  56 ′ of the bracket  56  and against the plate portion  47 . The angular position of the ribbon guide  51  relative to the plate  46  and the print head  37  can be changed by rotating the screw  57 . Rotation of the screw  57  causes the guide  51  to pivot about the stud  52 . The compression spring  59  retains the guide  51  in its adjusted position. A mounting plate  60  which constitutes a heat sink for the print head  37  is secured to the underside of the plate  46  between the guides  49 . The plate  54  is movably supported by and against the upper surface of the plate  60 . Screws  61  secure the plates  46  and  60  to each other. Compression springs  62  are received in cup-shaped members  63  in the shelf  44  and bear against the upper surface of the plate  46 . A tab  64  having an aperture  65  is secured to the plate portion  46 . The tab  64  projects into a cross-shaped recess  66 . The recess  66  has a first slot portion  67  which receives the tab  64  with clearance. The recess  66  also has a second slot portion  68  which bottoms out as shown in FIG. 2 for example. The slot portions  67  and  68  are perpendicular to each other. A round pin  66 ′ passes through the hole  65  with clearance and rests in the slot portion  68 . When the printer is in the operating position, the springs  62  are under greater compression than when the print head  37  is moved away from the platen roll  38 . As seen in FIGS. 2 and 4, the shelf  44  has elongate grooves  69 . In the position of FIG. 2, the knife edge  48  is spaced from parallel grooves  69 . When the print head  37  and platen roll  38  are separated, the springs  62  will urge the print head assembly  45  to a position at which the knife edge  48  bears against one of the grooves  69  as shown in FIG. 3. Thus, the print head assembly  45  is held in approximately aligned position relative to the platen roll  38 .  
         [0036]    The mounting section  40  is shown to have a pair of annular portions  70  having aligned holes  71 . Mounting section  39  (FIG. 5) also has a pair of annular portions  72  with opposed studs  73  received in the holes  71 . The annular portions  72  also have studs  74  which are received in arcuate slots  75  in annular portions  70 . The studs  74  cooperate with the ends of the slots  75  to limit the amount of rotation of the mounting section  40  relative to the mounting section  39 .  
         [0037]    With reference to FIG. 5, the mounting section  39  is shown to include an outer wall  35 ′. The wall  35 ′ mounts a pair of latches  76  guided in respective guides  77  and urged in opposite directions by compression springs  78 . The latches  76  are manually movable and accessible through openings  79 . The latches  76  have respective latch teeth  80  received in opposed pockets  81  (only one of which is shown in FIG. 2). The wall  35  is secured to the outer wall  35 ′ by screws  82 .  
         [0038]    With reference to FIG. 7, the assembly  46  is shown in exploded form. Member  83  is shown to have a pair of latching grippers  84 . As shown in FIGS. 2 and 8, the gripper  84  grips a surface  85  in the ink ribbon cartridge housing  23 . The member  83  has a pair of spaced depending portions  86  which have aligned holes  87 . A rod  88  passes through the holes  87  and through aligned holes  89  in a member  90 . A rod  91  passes through holes  92  in the member  90  and through a hole  93  in a fixed member  94 . When the assembly  46  is in the position shown in FIGS. 2 and 8, the members  83  and  90 , which form a toggle linkage, are in an overcenter or latching condition. As shown for example in FIG. 8, the grip member  85  on the cartridge housing  23  is gripped by the latching gripper  84 . The rod  88  overcenter with respect to a centerline CL to provide a toggle linkage or mechanism.  
         [0039]    As seen in FIGS. 2 and 8, a leaf spring  83 ′ secured to studs  89 ′ on the member  83  is used to urge the carrier web W against the platen roll  38 . The leaf spring  83 ′ ensures that there is sufficient contact between the carrier web W and the platen roll  38 . The leaf spring  83 ′ has a connector portion  83 ″ with holes  83   a . Oversize holes  83   b  in the leaf spring  83 ′ allow fasteners  83   c  to pass freely therethrough and to be press fitted onto the studs  89 ′.  
         [0040]    As seen in FIG. 8, a screw  83   d  is adapted to hold an optional tear bar (not shown).  
         [0041]    With reference to FIG. 10, a drive mechanism is generally indicated at  94 . The drive mechanism  94  includes an electric motor  95  for driving a gear  96 . The gear  96  meshes with gears  97  and  98 . Coaxially secured to the gear  97  is a gear  99  which meshes with a gear  100 . The gear  100  has a non-circular hole  100 ′ which receives a non-circular end portion  101  of a shaft  102 . The platen  38  is comprised of a sleeve of resilient frictional material on the shaft  102 . The shaft  102  is mounted in spaced bearings  103 . The bearings  103  are mounted in bearing housings  103 ′ mounted in the housing  21 .  
         [0042]    The gear  98  is secured to an axially aligned gear  104  which meshes with a gear  105 . The gear  105  meshes with a gear  106 . The gear  106  is secured to an axially aligned tubular clutch member  107 . A tubular clutch member  108  has an end wall  109  with a non-circular hole  110 . A wrapped clutch spring  111  has a first spring portion  112  received by the outside surface of the clutch member  107  and a second spring portion  112 ′ received by the inside surface of the clutch member  108 . A shaft  114  having a non-circular end portion  115  is received in the hole  110  so that the clutch member  108  and the shaft  114  rotate as a unit. The shaft  114  is secured to a disc  116  with three hook-shaped connectors  117  which couple to a drive member  118  for rewinding the ink ribbon IR in the ink ribbon cartridge  24 . The drive member  118  includes a rod  119  telescopically received in the shaft  114 . A spring  120  is also received in the shaft  114  and pushes on the rod  119 . The connectors  117  couple to the drive member  118  and enable the drive member  118  to shift against the force of the spring  120  when the cartridge is being installed into the printer. When the motor  95  is operated, the platen roll  38  is driven and the drive member  118  is driven through the spring clutch  113  comprised of the clutch members  107  and  108  and the clutch spring  111 . The clutch  113  assures that the proper tension is applied to the ink ribbon IR so that the ink ribbon is properly wound up in the cartridge.  
         [0043]    The drive mechanism  94  is assembled using a frame member  121  secured to the housing  21 . A bracket  122  and the frame member  121  rotatably mount motor  95 , gears  97  and  99 ,  98  and  104 , and  105 , the shaft  114 , and one of the bearing housings  103 ′.  
         [0044]    With reference to FIG. 11, there are shown housing sections generally indicated at  130  and  131 , the ink ribbon IR, a tubular core or spool Cl on which the ink ribbon IR is wound into a roll R 1  and a tubular core or spool C 2  on which the used or spent ink ribbon is wound.  
         [0045]    The cartridge housing  23  is comprised of the housing sections  130  and  131 . The housing section  130  has an axially extending shaft member  132  with a planar end surface  134  and an axial reduced-diameter end portion or projection  133  extending from the planar surface  134 . There is an axial hole  135  in the projection  133 . The shaft member  132  extends outwardly from a wall  136  of the housing section  130 . The housing section  131  has a shaft member  137  projecting from a wall or plate  138  of the housing section  131 . The shaft member  137  terminates at a surface  139 . A recess  140  in the shaft member  137  receives the projection  133 . The housing sections  130  and  131  can be suitably connected either permanently as by a permanent adhesive or releasably. A screw  141  is shown to pass through a hole  142  within the shaft member  137  and to be threadably received in the axial hole  135  in the projection  133 . As shown, the shaft members  132  and  137  are hollow.  
         [0046]    A brake generally indicated at  143  is shown to comprise a tubular or sleeve member  144  having a frictional outer surface  145 . The sleeve member  144  has a central hole  145 ′ for receiving the projection  133 . The sleeve member  144  is comprised of resilient closed-cell foam material and is positioned between surfaces  134  and  140 . The distance between the surfaces  134  and  140  in their assembled position is less than the length of the sleeve member  144  in its unassembled, unrestrained condition so that the sleeve member  144  is slightly compressed in the axial direction in the position shown in FIG. 13. In that the sleeve member  144  is compressed, the sleeve member  144  is more dense than it is in its unrestrained condition prior to assembly. The shaft members  132  and  137  are stationary and the sleeve member  144  is held stationary on the projection  133 . The outer surface  145  of the sleeve  144  is in frictional contact with the inner surface  146  of the core C 1 . The core C 1  can be composed of either plastic or cardboard. This causes a braking force or drag to be applied to the core C 1  to maintain tension in the ink ribbon IR. The rotation of the platen roll  38  is sufficient, however, to cause the braking force exerted by the brake  143  to be overcome so that ink ribbon IR can be paid out or drawn from the ink ribbon supply roll.  
         [0047]    The wall  136  also mounts a drive spindle  147  as best shown in FIG. 14. The spindle  146  is rotatably received in an internally-stepped annular portion  148 . An internal flange  149  on the annular portion  148  is received between annular projections  150  and  151  on the spindle  147 . The drive spindle  147  is, thus, held captive in the annular portion  148 . A drive head  152  has a stud  153  which cooperates with any one of the grooves  118 ′ in the drive member  118 . As the drive member  118  rotates, the drive head  152  is driven via stud  153  to drive the core C 2 . The drive spindle  147  has a drive lug  154  which engages a notch  155  (FIG. 11) in the core C 2 .  
         [0048]    The core C 2  is supported both on the spindle  147  and on a shaft member  156 . Posts  157  and  158  secured to respective walls  136  and  138  can be connected by a screw  159  passing through a hole  160  in the post  158  and threadably received in the post  157 .  
         [0049]    As best seen in FIG. 15, the housing sections  130  and  131  are positioned end-to-end. The upper housing member generally indicated at  161  is spaced upwardly from lower housing member  162  by an open space  163 . As seen in FIG. 3, the cartridge  24  is inserted onto the printer  20  by moving the cartridge  24  relative to the shelf  44  and the print head assembly  45  until the cartridge  24  has been slid to the position shown in FIG. 2. The housing member  161  is tapered toward the center CE where the housing section  130  and  131  abut and the two abutting portions  130 ′ and  131 ′ which constitute the housing members  161  are flexible and resilient enough to deflect during assembly onto the printer  20  until arcuate portion  164  enters a recess  165  in the shelf  44 . Thus, as the cartridge  24  is slid onto the printer  20  and the print head assembly  45  and the shelf  44  enter the open space  163 , the arcuate surface  164  finally detents into the recess  165  to hold the cartridge  24  detented essentially in its operating position.  
         [0050]    It is to be noted that the cartridge housing  23  has slots  166  which permit the guides  49  to clear the cartridge housing  23 . Upon such installation of the cartridge  24 , the mounting section  39  can be pivoted on posts  41  counterclockwise as seen in FIG. 3, and thereupon the mounting section  40  can be pivoted counterclockwise about posts  73  until the guides  49  locate on the bearing housing  103 ′, as seen in FIG. 9. This causes the print head  37  to be located precisely relative to the platen roll  38 .  
         [0051]    Thereupon the assembly  46  can be moved to the generally vertical position (FIG. 3) so that the latching gripper  84  can engage the grip member  85  on the cartridge housing  23 . Thereupon the manually engageable member  90  can be pressed inwardly until the shaft  88  is in the overcenter position with respect to the centerline CL as shown in FIG. 8.  
         [0052]    When the assembly  46  is latched, the arm portions  44 ′ which have notches  44   a  are urged by webs  130   c  and  131   c  against the stop  21   a , thus locating the cartridge  24  in its operating position.  
         [0053]    Other embodiments and modifications of this invention will suggest themselves to those skilled in the art and all such of these as come within the spirit of this invention are included within its scope as best defined by the appended claims.