Device Comprising a Printing Mechanism

The invention relates to a device, comprising a printing mechanism, means for transporting paper sheets by driving rollers and means for transporting endless paper by a tractor. A device of the kind mentioned above, i.e. an office machine is described, for example, in German Patent Application P 3807807. In the construction described, the tractor is situated behind the printing roller and is pivotably arranged so as to operate either in the pushing or in the pulling position.

Of interest are commonly owned copending applications Ser. No. 487,674 filed Mar. 1, 1990 entitled "Device for Adjustment of a Printer," Ser. No. 317,376 filed Mar. 1, 1989 entitled "Office Machine," and Ser. No. 317,378 entitled "Office Machine" all in the name of M. Rosenthal and Ser. No. 321,620 filed Mar. 9, 1990 in the name of Durr et al.

The invention has for its object to provide a device of the kind mentioned above, in which several kinds of papers can be supplied in a simple manner without much effort being required for changing over from one kind of paper to the other. According to the invention, this object is achieved in that the printing mechanism is preceded by a single feeding region for paper sheets and endless paper, having an entrance for manually feeding paper sheets, a tractor for the transport of endless paper arranged fixedly under the entrance and at least one cassette for automatically feeding paper sheets, which cassette is detachably arranged above the entrance and is inclined obliquely forwards. Thus, paper can be fed to the printing mechanism along three different paths, which are joined to form one single path before the driving rollers arranged in front of the printing mechanism. This common path is maintained until the first pair of rollers arranged behind the printing mechanism is passed. It is not until then that the paper paths for paper sheets and endless paper are separated. An ergonomically favourable operation becomes possible due to the oblique arrangement of the feeding cassettes. Further, due to the oblique arrangement in the feeding region, a sufficiently large space is obtained under the cassettes so that without any problem paper sheets can be fed by hand into the entrance thus formed. In order that endless forms can be introduced into the tractors arranged under the entrance, the supporting plate for manual feeding in the entrance can be removed. Due to the rectilinear transport of all kinds of paper, a relative displacement of copies or a bulging due to the different radii of curvature is avoided. Different kinds of paper can be processed without exchange or removal of a function unit upon change of the modes of operation. The magazines, i.e. cassettes for paper sheets, arranged obliquely towards the operator in an ergonomically favourable position in an adjacent area permit an easy and readily controllable filling without it being required to enlarge the magazines.

The stacker for the paper sheets is preferably located on the upper side of the office machine behind the printing mechanism and is likewise inclined obliquely forwards. Due to the fact that both the cassettes and the stacker for the paper sheets and the longitudinal axis of the printing mechanism are arranged as far as possible in parallel forwardly inclined planes, a simple operation of the whole apparatus is obtained. Further, the cassettes, the printing mechanism and the stacker are preferably arranged with respect to each other in such a manner that paper paths are obtained which extend substantially obliquely upwards. Thus, there is sufficient room in the hindmost lower region of the office machine for the electronic systems and other devices.

FIGS. 1 and 2 of the drawing show an embodiment of the article according to the invention.

FIG. 1 is a perspective view of a needle printer and

FIG. 2 shows a diagrammatic side elevation of the printer partly in sectional view.

The printer shown in FIGS. 1 and 2 has for feeding separate and endless paper a single feeding region located in the front part. The feeding region has a detachable supporting plate 10 for forming an entrance 11 for manually feeding paper sheets and a tractor 12 arranged under the supporting plate 10 for feeding and transporting endless paper. In FIG. 2, three detachable cassettes 13 for automatically feeding paper sheets are arranged above the entrance 11. The cassettes 13 are separate units having a motor drive, the electrical connections being established by incorporated sliding or clamping contacts. The cassettes are suspended detachably through hooks 15 and nipples 16. Reference numeral 17 designates a printing roller and reference numeral 18 designates a printing head, which is arranged so as to be displaceable in the longitudinal direction on a carriage denoted by reference numeral 19. Reference numerals 20, 21, 22 and 23 designate pairs of rollers, each pair of rollers comprising a driving roller provided with the subscript a and a pressure roller provided with the subscript b. The rollers of each pair are arranged separately beside each other and extend in the longitudinal direction of the printer (normal to the plane of the drawing)"; The paper path for endless paper is designated by reference numeral 24, the path for manually feeding paper sheets is designated by reference numeral 25 and the path for automatically feeding paper sheets is designated by reference numeral 26. By means of a switch 27, which is arranged behind the printing head 18 and is displaceable upon the change-over of the kind of paper, the paper sheets are stacked in a stacker 28 and the endless paper is ejected at an outlet 29, whose upper part takes the form of a tearing edge. The cassettes 13, the stacker 28 and the central axis 30 of the printing head 18 are located in parallel planes. The cassettes 13, the printing head 18 and the stacker 28 are arranged with respect to each other in such a manner that a paper path extending obliquely upwards is obtained. Due to this obliquely ascending paper path, the hindmost space of the printer offers sufficient room for devices, for example the electronic system. FIG. 1 shows on the righthand side the control panel 31.