Abstract: A blind stitch sewing machine comprises in the transmission between its main drive shaft and the fabric feeder an arrangement for stitch shortening and tacking. This arrangement comprises a coupling device with two arms which are guided for movement in longitudinal direction relative to each other and coupled by a coupling spring. One of the arms, which is fixed to the fabric feeder for movement therewith is provided with a recess into which a solenoid operated bolt is engageable when the fabric feeder reaches its forward end position to thereby stop the one arm and the fabric feeder connected thereto, while the main drive shaft and the remainder of the transmission remain in operation. Thereby feed of the fabric is substantially stopped and the seam tacked. Subsequently thereto the bolt is withdrawn from the recess and the coupling spring will again couple the one arm to the drive.

Abstract: Arrangement for retaining at least two approximately mutually parallel extending tubes, including an adapter having an aperture through which the tubes are conducted. A clamping element is arranged in the aperture intermediate the tubes and presses these against the wall structure of the aperture.

Abstract: A device for ducting process gas in a centrifuge block, comprising a hood for sealingly covering the centrifuge block and for defining at least one duct for the process gas. One embodiment has tubes within the hood in communication with connecting openings in centrifuge housings of the centrifuge block. According to a second embodiment, the tubes may be serpentine. A third embodiment has ducts formed directly in the hood, while a fourth has partitioning walls within the space enclosed by the hood for dividing the space into ducts.

Abstract: An improved blind stitch sewing machine wherein the upper end position of a reciprocating plunger element below the curved oscillating needle is not changed by slight irregularities in the feed and is automatically adjusted to an increase in thickness of the sewing material, such as seams, providing an adjustment which is maintained over the width of the thickness increase.

Abstract: A pressure plate is mounted on a vertical support for holding material. A material deflector is pivotally mounted with respect to the support and is adapted to deflect the material against the pressure plate. The pressure plate and the material deflector are formed with cooperating opposed faces for folding the material and with a needle guide for passage of a needle through the folds. A needle to which thread is fed, is held on a carrier and is movably mounted on the support to carry the needle into and out of the needle guide. A clamping device is arranged at the rear end of the needle guide to grasp the thread, and a cutter means is located at the front end of the needle guide to cut the thread. All of the elements are sequentially operated by a single actuator.