Abstract: A method for producing ? crystals of ethyl (R)-2-[4-(6-chloro-2-quinoxalin-2-yloxy)phenoxy]propionate, which is characterized by heating ? crystals, or ? crystals and ? crystals, within a range of from 50° C. to lower than the melting point of the ? crystals.

Abstract: A method for producing high melting point crystals, which is characterized by heating ethyl=(R)-2-[4-(6-chloro-2-quinoxalyloxy)phenoxy]propionate in the form of low melting point crystals, or low melting point crystals and high melting point crystals, within a range of from 50° C. to lower than the melting point of the low melting point crystals.

Abstract: A method for producing &bgr; crystals of ethyl (R)-2-[4-(6-chloro-2-quinoxalin-2-yloxy)phenoxy]propionate, which is characterized by heating &agr; crystals, or &agr; a crystals and &bgr; crystals, within a range of from 50° C. to lower than the melting point of the &agr; crystals.

Abstract: In order to eliminate a delay in a driving system and a control system during sequential operation of various component parts, to thereby realize a high speed and easy multi-axis control, a work delivery and removing device (7), a grindstone retracting device (14) and a gauge retracting device (19) are driven by respective compact electric motors (15, 13, 18) through associated reduction gear units. A reference pulse generator (34) for sequencers for generating reference pulses is provided, which reference pulses are distributed by a pulse distributor (35) to various position change curve setting units (36A, 36B, 36C). The position change curve setting units (36A, 36B, 36C) are a so-called electronic cam and output in response to receipt of the corresponding reference pulses respective position commands representative of predetermined position change curves (a, b, c). Servo-controllers (37A, 37B, 37C) are used for controlling the electric motors (15, 13, 18) in response to these outputs.