System for generating stitch pattern signals for electronic sewing machine

In an electronic sewing machine in which the information relating to the stitching needle movement and to the feeding dog movement are stored in a static memory, is read out in timed relation to the rotation of the machine main shaft and is fed to drive means for controlling the amount and direction of the stitching and feeding movements to form stitch patterns, a system for generating stitch pattern signals comprising:

• a static memory storing output data relating to the amount of bight or feed and storing order instructing data specifying the order in which the output data is to be read out, the output data and order instructing data being arranged in the static memory as bight relating data and feed relating data,
• a pattern selecting unit for giving output address signals for accessing head data of a predetermined pattern forming program from the data stored in the static memory when operated by a machine operator,
• a temporary memory for temporarily storing the output data read out from the static memory until the next output data is received and for transferring the stored output data to a pattern control unit for directly controlling the stitching needle movement and the feeding dog movement,
• a control unit for receiving the output signal read out from the static memory and an address signal for specifying the address of the output signal, and the control unit including means for supplying to an address unit the address signal to be subsequently fed to the static memory, the control unit further including means for producing control signals for controlling the operation timing of the components of the system,
• an address unit for temporarily storing the address signal to be used for the next address specification and which is received directly from the control unit or is prepared by the address unit in response to a control signal from the control unit, the address signal being stored until the next stitching movement or feeding movement is performed,
• a reference signal generator for giving the control unit reference status signals for the control signals to be given by the control unit to the components, and
• a timing pulse generator for feeding bight and feed timing signals to the control unit in timed relation to the rotation of the machine main shaft to cause the control unit to control the data to be produced from the address unit and the data to be produced from the temporary memory, alternately with respect to the bight and feed data.