Hitachi Koki Co., Ltd.

Koichi Yageta

Yoshikane Matsumoto

Toshio Hiki

Hirotaka Kobayashi

Yuji Ohmura

In a dot line printer including a cylindrical platen for supporting a print paper and a hammer bank supporting a plurality of print hammers, the hammer bank is a double bank structure in which a first half of the print hammers are attached to the upper bank and the second half of the print hammers are attached to the lower bank. The positions of print pins in adjacent print hammers are shifted an amount corresponding to one dot so that a predetermined dot lines are printable with one scan of the hammer bank. In order to minimize the hammer gaps of the print hammers, the inner surfaces of the hammer banks are oriented in a direction in which those surfaces access to each other.

Dot line printer with mimimum hammer gap arrangement

In a dot-line printer, a hammer bank carrying a plurality of dot printing hammers reciprocally moved along a printingline. Each of the printing hammers is made up of a leaf spring, one end of which is fixedly secured to the hammer bank and to another end of which a printing pin is attached. According to the invention, the plurality of dot printing hammers are separated into an odd-number group and an even-number group, in which the printing hammers in each of the odd-number and even-number groups are further separated into a predetermined number of sub-groups. The printing hammers in the odd-number group are arranged in the upper side of the printing line so that the printing pins extend downwardly and the printing hammers in the even-number group are arranged in the lower side of the printing line so that the printing pins extend upwardly. The printing pins in each of the sub groups of the odd-number group are positioned along a straight line inclined by a predetermined angle with respect to the printing line and the printing pins of the printing hammers in each of the sub groups of the even-number group are positioned along another straight line parallel to the aforementioned straight line. In order to facilitate fabrication of the printing hammers, the printing hammers in each of the sub groups are formed integrally to be in a comb-like shape.

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Katsuta, Japan

Koichi Yageta