The present invention relates to a force measuring device (10) for measuring the web tensions of a plurality of spaced apart longitudinal strips (5) of a longitudinally cut running material web that comprises a longitudinal direction defined by the running direction of the material web and a transverse direction, the force measuring device comprising an axle (12) and, supported on the axle, a measuring roll (20) wrapped around by the material web. Here, it is provided that the measuring roll is formed as a segmented measuring roll (20) having a plurality of measuring segments (22), the measuring segments (22) are arranged on the axle (12) in a respective measuring position, such that the spaced apart longitudinal strips (5) of the running material web wrap around in each case one or more measuring segments (22) and each measuring segment (22) is wrapped around by at most one longitudinal strip (5), each measuring segment (22) includes a dedicated load cell (26) for determining a web tension fraction of the longitudinal strip (5) wrapped around the measuring segment, the load cell providing a mount with which the measuring segment (22) sits on the axle (12), the force measuring device further comprising an evaluation unit (18) to which the measuring segments (22) are connected via electrical conductors and to which the measuring signals supplied by the load cells (26) in the measuring segments (22) are conductible, and the evaluation unit (18) comprising a web tension aggregation means (19) that is arranged and adapted to determine, for each longitudinal strip (5), from the web tension fractions that are determined by the load cells (26) of the measuring segments (22) wrapped around by said longitudinal strip (5), the total web tension of the longitudinal strip (5).

The present invention is to provide a sheet aligning apparatus that is capable of detecting misalignment. A control portion of a post-processing apparatus causes a front aligning member and a rear aligning member to be moved to an aligning position to align sheets conveyed to a processing tray, causes the front aligning member to be moved from the aligning position to a detecting position, and determines whether an electrostatic capacitance sensor detects misalignment (sheet shifting from a sheet bundle). When it is determined that the sensor detects misalignment, the front aligning member is moved from the detecting position to the aligning position so that sheets are realigned.

An image-forming apparatus that is capable of accurately detecting skew angle when arriving at a resist roller. In the image-forming apparatus, the resist roller feeds the printing paper to a printing unit at specified timing, and the printing unit performs printing on the printing paper. The flat-conveying section is formed between the paper-supply roller and the resist roller, and conveys the paper in a flat state. The camera takes images of the edge of the front end of the printing paper that is conveyed in the flat-conveying section. The camera-driving apparatus causes the camera to move along the flat-conveying section at the designed conveying speed of the printing paper. The skew-detection unit, based on images taken in the flat-conveying section by the camera, detects the skew angle when arriving at the resist roller as the arrival skew angle.

A sheet detection unit includes a photo-interrupter, a shutter holder, and shutter members held to be movable relative to the shutter holder. The shutter members include a sheet rear end detection portion capable of switching an optical axis between a light-interrupted state and a light-transmitted state and each are supported to be movable to an abutment position where the shutter member causes an abutment surface to protrude, and also movable to a retracted position where the shutter member is retracted from a sheet conveyance path. Based on a detection signal output from the photo-interrupter by the sheet front end detection portion and the sheet rear end detection portion moving relative to the optical axis, a control unit determines the presence or absence of a sheet.

A sheet pile supporting assembly (24) for a sheet material processing machine is presented. It comprises a plurality of sheet pile supporting bars (28) and a movable guiding means for selectively moving one or more of the sheet pile supporting bars (28) from a retracted position to an extended position. Additionally, an automatic selection unit (30) is provided for automatically selecting the sheet pile supporting bars (28) to be moved to the extended position and for coupling the selected sheet pile supporting bars (28) to the movable guiding means. Moreover, a method for operating a sheet pile supporting assembly (24) for a sheet material processing machine is explained.

According to one embodiment, a sheet conveying device includes a tray, a pickup roller, a movement mechanism, a holder, a biasing unit, and a detecting mechanism. The movement mechanism moves the tray between a raised position and a lowered position. The raised position is a position where sheets come into contact with the pickup roller. The holder holds the pickup roller so that the pickup roller is displaceable when pushed up by the sheets. The biasing unit applies a biasing force to the holder pushing down the pickup roller. The detecting mechanism detects when the sheets push up the pickup roller. The detecting mechanism includes a detection unit and a sensor. The detection unit is switchable between a reference position and a detection position according to displacement of the holder accompanying the movement of the tray. The sensor detects when the detection unit reaches the detection position.

Sheet media jams are detected along a media transport path by one or more vibration sensors that capture mechanical movements of components along the path that interact with the sheet media for driving or guiding the sheet media along the transport path. The detected vibrations during the advancing of the sheets are analyzed for distinguishing between detected vibrations associated with normal handling of the sheets and detected vibrations associated with abnormal handling of the sheets. An error condition can be signaled to a control system in response to distinguishing the detected vibrations associated with the abnormal handling of the sheets.

The present invention is to provide a sheet aligning apparatus that is capable of detecting misalignment. A control portion of a post-processing apparatus causes a front aligning member and a rear aligning member to be moved to an aligning position to align sheets conveyed to a processing tray, and determines whether an electrostatic capacitance sensor detects misalignment (sheet shifting from a sheet bundle). After the control portion determines that there is no misalignment, the control portion performs detection strength adjusting for a sensor and initial value setting for detecting misalignment of a next sheet.

Sheet media jams are detected along a media transport path by one or more vibration sensors that capture mechanical movements of components along the path that interact with the sheet media for driving or guiding the sheet media along the transport path. The detected vibrations during the advancing of the sheets are analyzed for distinguishing between detected vibrations associated with normal handling of the sheets and detected vibrations associated with abnormal handling of the sheets. An error condition can be signaled to a control system in response to distinguishing the detected vibrations associated with the abnormal handling of the sheets.

The present invention is to provide a sheet aligning apparatus that is capable of detecting misalignment. A control portion of a post-processing apparatus causes a front aligning member and a rear aligning member to be moved to an aligning position to align sheets conveyed to a processing tray, and determines whether an electrostatic capacitance sensor detects misalignment (sheet shifting from a sheet bundle). After the control portion determines that there is no misalignment, the control portion performs detection strength adjusting for a sensor and initial value setting for detecting misalignment of a next sheet.