Abstract: A high frequency sewing machine for intermittently transferring a work material mounted on a work material mounting plate by means of feed dogs which perform synthetic circular movement in horizontal and vertical directions and which cooperate with a presser foot to effect the continuous bonding of the overlapped portions of a fiber cloth which are continuously bonded together by means of a thermoplastic resin tape held between the overlapped portions of the fiber cloth in the work material to melt under high frequency dielectric heating. High frequency power is applied between a pair of planar electrodes respectively disposed above and below the work material during the time when the transfer by these feed dogs is stopped to effect the melting process. The occurrence of defective products having burn or the like due to heat concentration can be prevented while obtaining assured uniform bonding strength by using the high frequency power.

Abstract: A high frequency sewing machine for intermittently transferring a work material mounted on a work material mounting plate by means of feed dogs which perform synthetic circular movement in horizontal and vertical directions and which cooperate with a presser foot to effect the continuous bonding of the overlapped portions of a fiber cloth which are continuously bonded together by means of a thermoplastic resin tape held between the overlapped portions of the fiber cloth in the work material to melt under high frequency dielectric heating. High frequency power is applied between a pair of planar electrodes respectively disposed above and below the work material during the time when the transfer by these feed dogs is stopped to effect the melting process. The occurrence of defective products having burn or the like due to heat concentration can be prevented while obtaining assured uniform bonding strength by using the high frequency power.

Abstract: An interlock stitch sewing machine for blindstitch hemming with a slippage preventing device is provided which is so constructed as to prevent slippage that is likely to occur due to a position error of a lower fabric portion of the fabric portions stacked by a top-stitching at the fabric end, or a locally deformed portion due to a cutting error, in the blindstitch hemming of a tubular article such as T-shirts or underwear. A top-stiching width guide and a fabric edge guide are oppositely disposed in front of a needle location. A slippage detecting sensor that detects the edge position of the lower fabric portion to detect the presence of slippage, is attached to the fabric edge guide. When the slippage quantity detected by the sensor exceeds a permissible slippage quantity, it is determined there is possibility of slippage, and an informing means is operated.

Abstract: The present invention relates to a ketene dimer sizing agent for paper making comprising a dispersed phase containing a ketene dimer and an aqueous continuous phase containing a dispersing agent, characterized by containing polymeric aluminum hydroxide and/or polymeric aluminum chloride. The ketene dimer sizing agent for paper making of the present invention can be preferably used in, for instance, a neutral paper making and the like since it is excellent in sizing effect and storage stability.

Abstract: A control circuit using a microprocessor comprises a time counting circuit; a main control logic circuit receiving a time signal from the time counting circuit; and an AC signal generator receiving a first signal from the time counting circuit and a second signal from the main control logic circuit. When the microprocessor is out of order, the AC signal takes continuous "1" or "0" level. The control circuit further comprises a detecting circuit for detecting an abnormal state of the AC signal and a control circuit for maintaining an apparatus to be controlled by the control circuit in a predetermined safe state when the detecting circuit detects the abnormal state of the AC signal.