【正文】 ath, said member being carried on one of said carriages, driving means for each of said first and second carriages, an 濟(jì)南大學(xué)畢業(yè)設(shè)計 外文資料翻譯 11 interferometer including a pair of light reflectors, movement of one of said reflectors relative to the other of said reflectors producing interference fringes on relative light and dark, said one reflector being mounted on said first carriage and said other reflector being mounted on said second carriage, a transducer for converting such fringes of relative light and dark into electrical pulses upon relative movement between said first and second carriages, means energizing said first carriage driving means, signal means connected to said transducer and operative upon receiving a first given number of electrical pulses for deenergizing said first carriage driving means and then energizing said second carriage driving means, said signal means being further operative upon receiving a second given number of electrical pulses to de energize said second carriage driving means and the n to energize said first carriage driving means. References Cited in the file of this patent UNITED STATES PATENTS 1,455,795 LoganMay 22,1923 1,744,642 KondoJan. 14,1930 1,814,701 IvesJuly 14,1931 2,123,276 EckerlinJuly 12,1938 2,506,141 DrouinMay 2,1950 2,527,338 StamnOct. 24,1950 2,575,367 StrongNov. 20,1951 2,702,393 MertonFeb. 22,1955 745,919 Great BritainMar. 7,1956 OTHER REFERENCES Jenkins and White,”Fundamentals of Optics,”second edition,1950 McGrawHill Book Co.,Inc.,New York,.,pages 247249.(C0py in ) 濟(jì)南大學(xué)畢業(yè)設(shè)計 外文資料翻譯 12 濟(jì)南大學(xué)畢業(yè)設(shè)計 外文資料翻譯 13 United States Patent Office, Ser. No. 739,123 網(wǎng)格劃 線機(jī) John T Ferris, Houston, Tex. 摘 要 本發(fā)明涉及到網(wǎng)格劃線機(jī)，更特別是 ，此設(shè)備為得到準(zhǔn)確的橫向劃長度廣泛的空白網(wǎng)格給與保障。an interferometer including a pair of light reflectors, one of said reflectors being mounted or said first carriage, the other of said reflectors being mounted on said second carriage,movement of said one reflector relative to said other reflector producing interference fringes of relative light and dark, a transducer for converting such fringes of relative light and dark into electrical pulses upon relative movement between said fist and said second carriages, means for effecting movement of said first carriage along its said path over a predetermined distance and then terminating such movement, activating means operative after pletion of said first carriage movement for moving said second carriage, and means connected to said transducer for energizing periodically said grid marking device upon receipt of a predetermined number of electrical pulses during movement of said second carriage. 2. A grid ruling apparatus as defined in claim l including means for stopping movement of said second carriage, said stopping means being energized in response to a given number of electrical pulses. 3. Apparatus for ruling a grid blank prising, first and second carnages movable along a fixed path parallel to said grid blank, an interferometer including a pair of light reflectors, movement of one of said reflectors relative to the other of said reflectors of said interferometer producing interference fringes, said one reflector being mounted on said first carriage and said other reflector being mounted on said second carriage, a transducer for converting light pulses into electrical pulses, a shield having an aperture therein concentric to said interference fringes to permit intermittent light pulses to impinge upon 濟(jì)南大學(xué)畢業(yè)設(shè)計 外文資料翻譯 8 said transducer during relative movement of said first and second carriages, setting means for effecting movement of said first carriage, first carriage stopping means connected to said transducer and energized responsive to transmission of a given number of electrical pulses for preventing further movement of said first carriage, activating means operative after energization of said first carriage stopping means for effecting movement of said second carriage, a grid marking device, one of said grid marking devices and said grid blank being mounted on said second carriage, and means connected to said transducer for .energizing periodically said grid marking device upon every receipt of predetermined number of electrical pulses during movement of said second carriage. 4. A grid ruling apparatus as defined. in claim 3 including means connected to said transducer for stopping movement of said second carriage, said stopping means being energized in response to 39。 (in FIG. 2) to the same distance to the right thereof. After the circuit of motor 8 has been opened, a delayed signal closes the circuit of motor 7 to move carriage I to the right in FIG. 2 and, hence, prism 19 first toward and then beyond prism 18 to the original position, shown in FIG. 2. Again, electrical pulses are fed 濟(jì)南大學(xué)畢業(yè)設(shè)計 外文資料翻譯 6 to the counter and control circuit 24 until in response to appropriate signal the circuit of motor 7 is opened. Subsequently, motor 8 is energized and the cycle repeated. Therefore, it is apparent that the carriages1and 2 can be moved along over indefinite lengths in step by step stages measured in terms of onefourth wave length of monochromatic light s