Abstract: In an office machine, for example a printer, with an endless paper transport mode via a tractor and with an individual paper transport mode via driving rollers, one mode of operation is changed to the other in a simple way. A two-armed rotary lever is rotatably mounted relative to the housing and is positively coupled selectively to a paper switch for deflecting the paper path in accordance with the selected mode and selectively to the drive of the tractor, in such a way that, during the connection and disconnection of the tractor drive for respective endless paper and transport and idle modes, a change-over of the path switch takes place simultaneously.

Abstract: A printing mechanism is preceded by a single feeding region for separate papers and endless papers. The feeding region comprises an inlet duct for manually feeding separate papers, a tractor for the transport of endless papers arranged fixedly under the inlet duct and at least one cassette for automatically feeding separate papers. The cassette is detachably arranged above the inlet duct and is inclined obliquely forwards.

Abstract: For a simple adjustment of a printer from paper sheet transport to endless paper transport mode and conversely, an adjustment assembly is adjustable through selective engagement by a ram of the print head carriage according to the carriage position and is in operative connection with an endless paper feed tractor, a paper path switch and pressure rollers to selectively place these elements in the sheet and endless paper feed modes.

Abstract: A device for supporting a printer drum in lateral walls of a housing includes a detachable bearing bushing mounted on one end journal of the drum. That one end journal of the drum is journalled in a closed bearing opening and the other end journal of the drum is arranged via the bearing bushing in a transversely open bearing of a supporting wall which is connected to one of the lateral walls, the bearing bushing can be locked to the supporting wall after rotation of the bearing bushing through a flexible and detent lockable lever connected to the bushing. The bearing bushing is assembled and disassembled by sequential longitudinal and transverse displacements relative to the open bearing, A guide trough aligns the drum journal with the closed bearing during assembly of the drum.

Abstract: An office machine, for example, a printer, with a printing unit, individual paper transport via driving rollers and endless paper transport via a tractor is to be designed in such a way that as many operating modes as possible can be obtained by simple means. This is achieved at least one releasable cassette for individual paper is in the entry region of a printing unit. A tractor is pivotalby adjustable into a pushing and a pulling position and is located behind the printing unit. The following operating modes are selectable by adjustment of the tractor positions coupled to further components:a. Straight individual paper transport from the front via driving rollers either by manual infeed or by automatic cassette infeed, the tractor being in the pushing position.b. Curved endless paper transport from the rear via the tractor set in the pushing position and via a portion of the driving rollers.c. Straight endless paper transport from the front via the tractor set in the pulling position.

Abstract: In an office machine, for example a printer, with a printing unit, with individual paper transport via pairs of rollers and with endless paper transport via a tractor, a release of the pressure rollers, which is necessary for the tractor to operate in the pulling mode, is carried out by means of two stops attached to the tractor, the pressure roller of a first pair of roller being released via the first stop, during the pivoting of the tractor up into the pulling position, and the pressure roller of a second pair of roller being released, in the pulling position of the tractor, during the inward pivoting of a pivoting housing part, on which the pressure roller of the second pair of rollers are arranged resiliently.

Abstract: The invention relates to a covering device for protecting the nozzle area of an ink jet writing head, which device is detachably connected to the ink jet writing head in a sealing manner and forms a cavity which is opened towards the nozzles, into which cavity liquid ink is transported through the nozzles. In order to be able to store and transport an ink jet writing head filled with liquid ink for a long period of time, in particular also as an individual component, for example as a spare part, without the possibility existing the liquid ink of drying in the nozzle area and without enclosed or penetrating air bubbles that can lead to a chemical change of the liquid ink, it is ensured that the covering device (7) is form-coupled to the ink jet writing head (1) and that the cavity (8) comprises a closable ventilation duct (12) which communicates with the atmosphere.

Abstract: A detachable paper transport device for a printer having a printing roller, using two transport chains. The device has two side walls on each of which a control lever is pivoted for selecting the spacing between the transport chain and the roller, to compensate for differences in the thickness or number of layers of the paper. The device side walls each have a slotted hole for engaging one member on the printer, and each control lever has a bearing lug for engaging another member on the printer to slide the device along the slotted holes.

Abstract: For the reliable guiding of a record carrier and the printing thereon as far as in the vicinity of the upper and lower edge, a pivotable device is arranged over the printing drum, said device comprising two or more flat hold-down devices which are arranged on a rotatable shaft. The hold-down devices can be slid into a first position in which they engage the printing drum and a second position in which they are lifted off the printing drum. In the first position, the record carrier is deflected to the printing drum during transport, and in the second position it is transported by additional pressure rollers. The device is pivotable about the printing drum into three positions and is constructed as a modular unit. This enables the simultaneous or alternating transport about the printing drum of different record carriers in a different manner.

Abstract: A paper web in an office machine is transported from the one side of a transporter (tractor) comprising a transport chain to the printing backing and back again on the other side of the transporter. In the case of multilayer paper webs, notably webs comprising more than four layers, an increasingly larger wave of the paper web tends to in front of the printing backing. In order to avoid such waves, the associated transporters comprise guide pieces for the paperweb which extend from the tractor to the vicinity of the zone of contact between the paper web and the printing backing and whose surface is situated at least substantially in the plane tangential to the printing backing at this zone of contact.