摘要:
The apparatus is provided with a holddown device (10) for a medium (6) lying on a platen (11), said device comprising first cockle-control means which in a medium output zone (9) downstream of the print zone (8) control an expansion of the medium (6) to be in the form of a wave defined by a plurality of bubbles and substantially adapted in frequence to a ridged surface of the supporting platen (11); the hoiddown device may comprise second cockle-control means which control an expansion of the medium (6) in the print zone (8) to be in the form of at least two parallel waves defined by a plurality of bubbles and alternated such that a downward bubble of one of the waves is adjacent to an upward bubble, or no bubble, of an adjacent wave in the direction (Y) of advance of the medium (6). The effects of cockle are successfully neutralised without tensioning the medium downstream from the printing zone, and avoiding vertical banding.
摘要:
A carriage slider rod (35) is mounted on a steel beam (11) by means of brass support elements (20). The support elements (20) are first riveted to the beam (11) and then have precisely aligned V-shape grooves (30) machined therein to provide accurate location for the slider rod (35). The slider rod (35) is screwed to the beam using central bores (24) passing through the support elements (20). To fix the support elements (20) to the beam, they are first located in respective apertures (19) and then deformed by a clenching tool, one jaw of which passes through an adjacent aperture (18) in the bottom wall of the beam.
摘要:
A scanning device such as a printer (30) has a trapezoidal carriage support beam (32) which permits a compact juxtaposition of the carriage slider rod (33), the printhead (36), a drive belt (71, 72) and an encoder device (50). A second slider mounting for the printer carriage (100) comprises a bushing (150) incorporating a part-spherical portion (65) and an arm (152) which engage with corresponding parts of the carriage.
摘要:
A media holddown device (10) comprises a plastics vacuum guide (14) attached to a sheet metal vacuum beam (80), the guide (14) comprising vacuum chambers (150, 151) in communication with the beam by means of openings (160) to control the negative pressures applied to media (12) of varying widths by a fan (82). Dividing walls (147) are provided between the chambers (150, 151) to maintain the value of the negative pressure larger than a predetermined value, especially for media (12) with conventional widths. An intermediate wall (153) divides the guide into front and rear chambers (150a, 150b) to increase the control of media leading edges. The number, size and pattern of arrangement of openings (160) are selected to produce desired air flow characteristics.