US 5,183,348 AGranted

Printer having tractor unit attachable to one of upstream and downstream sides of platen

AssigneeBrother Kogyo Kabushiki Kaisha

InventorHiroyuki Kato

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Abstract

To prevent concurrent mounting of two tractor units on an upstream side and a downstream side of a platen of a printer, a rocker member is pivotally mounted by a pivot pin on a side plate of a chassis to which the tractor unit is attachable. The rocker member has an upper end portion disposed close to an upper lock pin of a downstream side mounting portion. The lower end portion of the rocker member is disposed close to a lower lock pin of an upstream side mounting portion. When the tractor unit is locked with the lower lock pin, the lower end portion of the rocker member is firmly locked in position against rotation, so that the upper end portion of the rocker member is no longer separable from the upper rock pin, and hence, is able to prevent another tractor unit from moving into that portion.

Claims11

Dependent claims

A printer for printing an image on a printing sheet comprising;

a chassis;
a platen rotatably supported by the chassis for supporting and feeding the printing sheet in a sheet feeding direction, the platen defining a printing section;
a tractor unit for feeding the printing sheet to the printing section, the chassis providing a first tractor unit attaching portion positioned downstream of the platen with respect to the sheet feeding direction and a second tractor unit attaching portion positioned upstream of the platen, the tractor unit being selectively mounted on one of the first and second tractor unit attaching portions;
and
means for preventing another identical tractor unit of another printer from being attached onto one of the first and second tractor unit attaching portions if remaining one of the second and first tractor unit attaching portion has already accommodated therein the tractor unit.

2 more elements

Dependencies are inferred from the claim text.