Patent Publication Number: US-3878781-A

Title: Roller printer

Description:
United States Patent 1 Burkhardt et al.  
 [451 Apr. 22, 1975 221 Filed:  
 [ 1 ROLLER PRINTER [73] Assignees DIEHL datensysteme GmbH,  
 Nurnberg. Germany Sept. 24, 1973 21 Appl. No.: 399,959  
 [30] Foreign Application Priority Data Sept. 26 1972 Germany 2247175 Apr. 7. 1973 Germany 2317641 [52] US. Cl. 101/228; 101/244; 197/51 [51] Int. Cl 1341f 13/54 [58] Field of Search 101/244, 228, 232, 376,  
 l0l/l0l; 197/51, 18  
 [56] References Cited UNITED STATES PATENTS 3.203.345 8/1965 Gibbons 101/228 X 3.381.790 5/1968 Chaveneaud et a1. 197/51 3.735.700 5/1973 Roscr 101/228 Primary E.\&#39;aminer--Stephen C. Pellegrino Attorney; Agent, or FirmWalter Becker [5 7] 7 ABSTRACT A roller printer with a printing roller eccentrically located with regard to a driving shaft, in which the driving shaft carries out one revolution per printing operation, and in which a web of paper and an ink ribbon pass between the printing roller and the type wheels. Rotatable paper guiding rings are eccentrically arranged relative to the axis of the driving shaft in such a way that between the web of paper engaging the paper guiding rings and the ink ribbon within the printing area there is normally prevailing a distance which during the printing operation proper is bridged by the freely rotatable printing roller.  
 7 Claims, 4 Drawing Figures PATENTEBAPR22 1% sum 1 3 2 ROLLER PRINTER The present invention relates to a roller printer with a printing roller which is eceentrically located with regard to a driving shaft and in which the driving shaft carries out one revolution for each printing operation, while between the printing roller and the type wheels there is passedthrough a web of paper and an ink ribbon.  
  In connection with a roller printer it has become known between a printing roller and adjustable type wheels to arrange a web of paper and an ink ribbon. The printing roller is eceentrically and rotatably journalled in elastic discs arranged on a driving shaft. said driving shaft being adapted to carry out a revolution per printing operation.  
  It is an object of the present invention for a roller printer to provide paper guiding means which are com posed of a few parts only and which during the transport of the paper will avoid a smearing of the paper by the ink ribbon.  
  These and other objects and advantages of the invention will will appear more clearly from the following specification in connection with the accompanying drawings. in which:  
  FIG. I is a side view of a roller printer according to the present invention.  
  FIG. 2 is&#39; a top view of a portion of the roller printer according to FIG. 1.  
  FIG. 3 shows the roller printer of FIG. I with a roller body designed as finger protection.  
  FIG. 4 is a section through the roller body of FIG. 3, said section being taken along the IVIV of FIG. 3.  
  The roller printer according to the present invention is characterized primarily in that the paper guiding rings are eceentrically arranged with regard to the driving shaft axis in such a way that between the web of paper which engages the paper guiding rings, on one hand, and the ink ribbon within the region of the printing area, on the other hand, there is provided a space or distance which is adapted during the printing operation to be bridged by the freely rotatable printing roller.  
  This arrangement brings about the advantage that during the transport of the paper a space will exist between the ink ribbon and the web of paper. which space makes possible a transporting of the web of paper while assuring that the paper will not be smeared.  
  Referring now to the drawings in detail, it will be noted that the arrangement shown therein comprises a frame 1 in which frictionally engaging type wheels 3 are rotatably journalled on a main shaft 2. The main shaft 2 is, through a non-illustrated pairs of gears, operatively connected to a drive shaft 4 which is indirectly journalled in the frame 1. I  
  The drive shaft 4 respectively carries on both ends bearing discs 5, 6, in which a freely rotatable printing roller 7 is eceentrically journalled with regard to the drive shaft 4. Furthermore, in the frame 1 there are connected two bearing bodies 8, 9 on which two paper guiding rings l0, 11 are journalled with play. The bearing bodies 8, 9 have eccentric bores 9&#39; which serve for journalling the drive shaft 4. The axis of rotation 12 of these paper guiding rings 10, 11 is arranged behind the axis 13 of the drive shaft. A web of paper 15 engages the paper guiding rings 10, 11, and by pressing rollers 16, 16&#39; is pressed against the paper guiding rings 10, l l.  
  The pressing rollers l6, 16&#39; are connected to a motor-driven shaft 23 which, in a non-illustrated manner. is firmly journalled in the frame. In order that the pressing rollers l6. 16&#39; will be able to press against the paper guiding rings I0, 11 at the pressure necessary for transporting the paper, the distance between the axes of the paper guiding rings and said pressing rollers is less than the total of the radii of a paper ring 10, 11 and of a pressing roller I6, 16&#39;. The pressing roller l6, l6 preferably consists of soft, correspondingly deformable rubber material.  
  A paper deflector 17 extends between the paper guiding rings 10, 11. Between the type wheels 3 and the web of paper 15 there is an ink ribbon 19 passed over a roller 18. The space between the ink ribbon l9 and the web of paper 15 amounts to approximately 0.8 mm.  
  The adjusting phase for the type wheels 3 starts in the starting position of the printing roller 7, illustrated in FIG. I. This adjusting phase is completed shortly prior to the printing roller 7 passing the type wheels 3. The print on the paper web 15, effected by the nonillustrated types of type wheels 3, is effected by pivoting the printing rollers 7 along a circular line 20 and by subsequent rolling of the printing rollers 7 on the printing area 21. While the printing roller 7 continues moving along the dot-dash circular line 20, the paper transport is effected by the pressing rollers l6, 16 which are adapted to be driven in the direction of the Arrow 22.  
  The deformable pressing rollers l6, 16&#39; represent a cost-favorable solution over the heretofore customary knurled rollers which are arranged on shafts that are not firmly mounted in the frame.  
  In view of the eceentrically mounted paper guiding rings 10, II, it will be realized that the web of paper 15 will not be grooved when passing the printing roller 7.  
 Moreover. as a result thereof. the pressing rollers l6. 16&#39; are located outside the region of passage of the printing roller 7 and will not necessarily be deformed. Finally, the paper deflector which extends between the paper guiding rings 10, ll prevents the web of paper 15 from again entering the printer.  
  The paper guiding rings 10, II and pressing rollers 16, I6, which partly extend beyond the width of the web of paper 15, permit a line-true transport and spacing and a parallel line transport. Therefore, a uniform picture of the print of the printed-upon web of paper 15 will be obtained. The deformable pressing rollers l6, l6 engage not only the web of paper 15 but also the paper guiding rings 10, 11, whereby a direct drive of said paper guiding rings will be obtained.  
  According to FIGS. 3 and 4, a roller body 25 of any suitable synthetic material is connected to the drive shaft 4 by means of a screw 26. The shape of the roller body 25 is such that its sides are symmetrically arranged with regard to the axis of symmetry 25&#39; thereof (FIG. 4).  
  The printing roller 7 is arranged in a recess 27 of the roller body 25.  
  A web of paper 15 is passed over the paper guiding rings 10, 11 and extends below a tear-off rail 28 fixedly arranged in the frame. in an upward direction.  
  During a printing phase, in other words during an operation of the machine, the drive shaft 4, the driving discs 6, and the roller body 25 move from the illustrated starting position so as to rotate in the direction of the Arrow A. The non-controlled printing roller 7 is guided in this direction along a path of circulation. This path will at a printing area 21 bring about the roller point on the paper web on the correspondingly adjusted type wheel 3. Subsequently, a line transport of the paper web is effected by the pressing rollers l6, 16&#39;. This means for the paper insertion that a machine step has to be initiated a plurality of time in order to transport the web of paper 15 below the tear-off rail 28.  
  During the removal of the paper web 15 engaging the tear-off rail 28, a squeezing of the finger at the rail 28 by the rotating printing roller will be prevented by the roller body 25. Thus. the danger of hurting the finger is eliminated.  
  It is, of course, to be understood that the present invention is by no means limited to the specific showing in the drawings but also comprises any modifications within the scope of the appended claims.  
 What we claim is:  
  l. A roller printer for durably maintaining more uniform printing quality of a type which includes: frame means, a driving shaft rotatably journalled in said frame means. bearing means connected to said driving shaft for rotation therewith. a printing roller rotatably supported by said bearing means and arranged eccentrically with regard to said driving shaft, said driving shaft being operable to carry out a complete revolution per each printing operation, main shaft means rotatably supported by said frame means and drivingly connected to said driving shaft, type wheel means supported by said main shaft means for rotation therewith. cylindrical paper guiding means rotatably supported by said frame means and located eccentrically with regard to the axis of rotation of said driving shaft, said paper guiding means and said type wheel means being spaced from each other so as to define a gap therebetween representing the printing area of said roller printer, said paper guiding means being engaged by and guiding a web of paper to be printed upon through said gap, ink ribbon means, and means for normally passing said ink ribbon means through said gap in spaced relationship to said type wheel means and at such a distance from said paper guiding means as to be spaced from a web of paper in said paper guiding means within said gap, the location of said printing roller on said bearing means relative to the axis of rotation of said driving shaft and said paper guiding means being such as to press said ink ribbon against said type wheel means adjustable for printing free of any phantom printing when carrying out a paper advance and kept stationary when said printing roller passes through said gap.  
  2. A printer, according to claim I, which includes bearing bodies stationarily arranged in said frame means and rotatably supporting said paper guiding means and said driving shaft.  
  3. A printer, according to claim 1, in which said paper guiding means include two paper guiding rings eccentrically journalled, and which includes paper deflecting means extending between said paper guiding rings.  
  4. A printer, according to claim 1, in which said bearing means include a drum keyed to said driving shaft for rotation therewith and provided with a cut-out, and supporting means connected to said driving shaft for rotation therewith and rotatably supporting said printing roller.  
  5. A printer, according to claim 1, which includes auxiliary shaft means mounted in said frame means, motor means drivingly connected to said auxiliary shaft means for rotating same, and pressing roller means keyed to said auxiliary shaft means and operable to press a web of paper passed over only a peripheral portion of said paper guiding means against said paper guiding means to advance said web of paper to and through said gap with mimimized paper deformation, said pressing roller means and said paper guiding means extending beyond the width of the web of paper to be printed upon.  
  6. A printer, according to claim 5, in which the axial distance between said paper guiding means and said pressing roller means is less than the total of the radii of a paper guiding means and of a pressing roller means.  
  7. A printer. according to claim 6, in which said pressing roller means are of soft material adapted to be fulled.