发明名称 |
Automatic grade rod and method of operation |
摘要 |
A grade rod and method of operation for use in a surveying system employing a laser beam which is rotated in a plane. A flexible tape formed with a graduated scale is mounted for movement in a loop within the housing. A slider on the tape carries a pair of closely spaced-apart light detectors as well as electronic circuitry which discriminates between laser beam pulses and sunlight. Output signals from the circuitry on the slider are fed into a control circuit in the housing through a flexible cable which is carried in a traveling loop. Scale indicators are mounted for movement with the slider along a fixed scale which is provided on the housing, and a manually operated cursor is mounted for movement along the housing. The control circuit includes means for driving the tape and slider in a search mode until a light pulse from the laser hits a detector, and then in a track mode for centering the detectors on the plane of the laser beam. A circuit is provided for returning the slider to its home position should the beam be interrupted for a period of time, and also for returning the slider to its home position should no laser beam be detected. A stutter-start circuit is employed for operation in a track mode for a short time period after activation before switching to the search mode.
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申请公布号 |
US4030832(A) |
申请公布日期 |
1977.06.21 |
申请号 |
US19750548607 |
申请日期 |
1975.02.10 |
申请人 |
SPECTRA-PHYSICS, INC. |
发明人 |
RANDO, JOSEPH F.;SOBEL, ARTHUR;DAVIDSON, RICHARD W. |
分类号 |
G01B11/27;G01C15/00;(IPC1-7):G01B11/26;G01C3/08;G01C15/06 |
主分类号 |
G01B11/27 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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