Abstract: A space-saving centerless grinding machine having high operability is obtained by devising the configuration of component units around the basic configuration of the machine. A dressing means for performing a dressing process for a grinding wheel and a regulating wheel comprises a single dressing unit. The dressing unit is located at a lower position between the grinding wheel and the regulating wheel, and thus eliminates the need for right and left dresser spaces for grinding wheels that have most seriously affected the breadthwise dimension of a conventional centerless grinding machine, leading to space saving and a considerable reduction in the breadthwise dimension of the centerless grinding machine.

Abstract: A dressing device capable of effectively performing, in a centerless grinding machine, dressing to a grinding face of a grinding wheel and a rotary supporting face of a regulating wheel, performing relative positioning in axial direction of the grinding wheel and the regulating wheel after dressing, easily and accurately, and also reducing the equipment installation space. The dressing device includes a single dressing means for performing dressing to the grinding face of the grinding wheel and the rotary supporting face of the regulating wheel, this dressing structure including a rotary dresser having a profile fit for the grinding face of grinding wheel and the rotary supporting face of the regulating wheel.

Abstract: A roller bearing by far less costly and highly accurate compared with conventional products and having double-cone rollers as rolling elements. A plural number of track pockets are provided facing a pair of parallel bearing plates, double-cone rollers are swivelably and rollably held in the opposing pair of track pockets respectively, both the bearing plates are connected and held in a state relatively swivelable by a connecting mechanism.

Abstract: A vertical spindle duplex head for a grinder includes an annular pressure wheel and a receiver wheel arranged to rotate and revolve workpieces between the annular surfaces of the pressure wheel and the receiver wheel and a grindstone for one end portion of the workpieces driven in the opposite directions of rotation of the pressure wheel and receiver wheel and at their different rotational ratios. The workpieces rotate and revolve between these wheels, thereby grinding their end face by means of a grindstone arranged around the external periphery of a rotary carrier.

Abstract: A chuck for a workpiece comprising an annular piston housed in the main body of the chuck, an annular adjusting member supported on a cylindrical rod portion integral with the piston and movable only radially thereof, and three clamp levers pivotably mounted on the chuck main body and arranged at an equal spacing along the circumference thereof for radially driving clamp jaws on a front plate of the main body. Each of the clamp levers has a rear end in engagement with a tapered surface on the outer periphery of the adjusting member. With the portion of the workpiece to be machined held in its centered position, another portion of the workpiece is held by the clamp jaws, and three wedge-like lock members arranged between the cylindrical rod portion and the adjusting member at an equal spacing circumferentially thereof are individually advanced to lock the adjusting member.

Abstract: A pattern generating system for use in electronic sewing machines. Output-oriented data relating to the amount of bight or feed for a stitch pattern and order instruction-oriented data relating to the order in which the output-oriented data is read out are stored in a static memory (ROM) separately in such a manner as to distinguish between the data relating to bight and the data relating to feed. The data relating to the address at which the respective head data on stitch patterns is stored is stored at specified addresses in the static memory addressed by selection instructions corresponding to the stitch patterns given as by a pattern selecting button unit. The static memory is connected to a microcomputer which performs a control operation such that it indexes the static memory, analyzes order instruction-oriented data and updates addresses or gives the output-oriented data to a drive unit which controls the amount and direction of bight and feed.

Abstract: A speed control apparatus for use with an electric sewing machine having a motor drive control device for controlling the drive of the motor. The apparatus comprises a sensing device which can be optionally touched by the operator of the sewing machine, and a sensing signal generating circuit adapted to generate a signal in response to an electric change which is caused when the human body touches the sensing device, the arrangement being such that in response to the operator of the sewing machine touching the sensing device, the sensing signal generating circuit gives a predetermined signal to the motor drive control device, thereby stopping the drive of the motor.