Laser land-surveying apparatus with digital display

A laser land-surveying apparatus operable from an electrical power source for measuring linear displacement comprising:

• a swingably mounted laser beam source connectable to the power source for generating a laser beam;
• a motor for swinging said laser beam source to define a plane of light, said motor swinging said laser beam source at a predetermined angular velocity;
• a rigid grade pole spaced from said laser beam source and having a base and an apex;
• a laser beam detection unit mounted to said grade pole between base and apex for relative motion between said pole and said detection unit, including a laser beam detector operatively electrically connectable to the power source and capable of producing an electrical range input signal representative of the time duration in which said beam swings across said detector in response to detection of said laser beam;
• indicating means electrically connected to said detector and producing an indication perceptible to an operator in response to detection of the beam by said detector;
• measuring means electrically connectable to the power source and mechanically coupled between said laser beam detection unit and said grade pole to permit relative motion between said detection unit and said pole, said measuring means determining the distance between said laser beam detector and said base of said pole and generating an electrical grade signal containing information representative of the distance between said base and said laser beam detector;
• a digital display unit electrically connectable to the power source and electrically connected to said measuring means to receive said electrical grade signal from said measuring means and in response thereto to digitally, visibly display to the operator the numerical grade distance between said laser beam detector and said base of said grade pole;
• and
• electrical range calculating circuitry for determining the range distance between said laser beam source and said laser beam detector, said range calculating circuitry electrically connectable to the power source and electrically connected to said detector to receive from said detector said electrical range input signal representing the time duration in which said beam swings across said detector, said range calculating circuitry in response to said electrical range input signal generating a range output signal representing the distance between the laser beam source and said laser beam detector and being electrically connected to said digital display unit for selectively delivering said range output signal to said digital display unit, permitting said digital display unit to digitally, visibly display to the operator the range distance between said laser beam source and said laser beam detector.

A laser land-surveying apparatus operable from an electrical power source and usable with the beam from a laser beam source for measuring linear displacement comprising:

• a rigid grade pole having a base and an apex;
• a laser beam detection unit mounted to said grade pole between base and apex for relative motion between said pole and said detection unit, including a laser beam detector operatively electrically connectable to the power source;
• indicating means electrically connected to said detector and producing an indication perceptible to an operator in response to detection of the beam by said detector;
• measuring means electrically connectable to the power source and mechanically coupled between said laser beam detection unit and said grade pole to permit relative motion between said detection unit and said pole, said measuring means determining the distance between said laser beam detector and said base of said pole and generating an electrical grade signal containing information representative of the distance between said base and said laser beam detector;
• a digital display unit electrically connectable to the power source and electrically connected to said measuring means to receive said electrical grade signal from said measuring means and in response thereto to digitally, visibly display to the operator the numerical grade distance between said laser beam detector and said base of said grade pole;
• and
• said measuring means including an incremental encoder carried by said laser beam detection unit and having a rotatable shaft, said encoder generating an electrical signal representative of the angular displacement of said shaft, said measuring means further including a tape reel fixed on said encoder shaft and a tape tautly extending from said reel to said grade pole and fixed to said pole adjacent an end of said pole such that linear movement of said detection unit relative to said pole rotates said tape reel and said encoder shaft, permitting said encoder to generate said electrical grade signal representative of the angular displacement of said shaft and thus representative of the distance between said base and said beam detector.

A laser land-surveying apparatus operable from an electrical power source and usuable with the beam from a laser beam source for measuring linear displacement comprising:

• a rigid grade pole having a base and an apex;
• a laser beam detection unit mounted to said grade pole between base and apex for relative motion between said pole and said detection unit, including a laser beam detector operatively electrically connectable to the power source;
• indicating means electrically connected to said detector and producing an indication perceptible to an operator in response to detection of the beam by said detector;
• measuring means electrically connectable to the power source and mechanically coupled between said laser beam detection unit and said grade pole to permit relative motion between said detection unit and said pole, said measuring means determining the distance between said laser beam detector and said base of said pole and generating an electrical grade signal containing information representative of the distance between said base and said laser beam detector;
• and
• a digital display unit electrically connectable to the power source and electrically connected to said measuring means to receive said electrical grade signal from said measuring means and in response thereto to digitally, visibly display to the operator the numerical grade distance between said laser beam detector and said base of said grade pole.