Automatic surveying apparatus

Claim 1

An automatic surveying apparatus, comprising a controlled shaft having means for mounting said shaft along the longitudinal axis of a vehicle for free rotation around the longitudinal axis of said controlled shaft, an automatic level controller coupled to said controlled shaft for maintaining the angular rotational position of said shaft about its longitudinal axis constant with respect to the horizontal as the vehicle inclines from side to side, an elevation-measuring level fixedly mounted on said controlled shaft with the normally level position of said level parallel to the axis of said controlled shaft, whereby the horizontal position of the elevation-measuring level is changed as the longitudinal axis of the controlled shaft is inclined as the vehicle is inclined frontwardly or rearwardly, two lateral shafts rotatably mounted on said controlled shaft and extending laterally in opposite directions from said controlled shaft perpendicular to the longitudinal axis thereof and horizontally, one of said shafts being an adding shaft and the other being a subtracting shaft, a means for indicating a reference azimuth, said means being adapted to be mounted on said vehicle for producing a movement proportional to the change in direction of said vehicle relative to the reference azimuth, said means being coupled between said last-mentioned means and said adding and subtracting shafts for turning one of said shafts in one direction and the other in the other direction an amount proportional to the change of the direction of the vehicle from the reference azimuth, two departure-measuring levels, one fixed on each of said two shafts with the normally level position of each level parallel to the longitudinal axis of said controlled shaft, two latitude-measuring levels, one fixed on each of said two shafts with the normally level position of each level perpendicular to the longitudinal axis of said controlled shaft, each of said elevation-measuring levels, departure-measuring levels and latitude-measuring levels being liquid levels having liquid pressure-sensitive electrical resistance therein responsive to changes in the liquid pressure in said levels in proportion to the amount the position of the levels changes, each of said levels having an electrical circuit coupled thereto in which said resistances are incorporated for producing a current when the level is moved from its normal level position, power supply means coupled to said electrical circuits and adapted to be coupled to said vehicle to provide a power output in proportion to the speed of the vehicle, the circuits for said two departure-measuring levels being coupled to each other for producing a current flow in proportion to the departure of the vehicle from a point of origin, and the circuits for said two latitude-measuring levels being coupled to each other for producing a current flow in proportion to the latitude of the vehicle from a point of origin, and integrating means to which the circuits of the departure-measuring levels are coupled, to which the circuits of the latitude-measuring levels are coupled, and to which the circuit of the elevation-measuring level is coupled for integrating the outputs of said circuits.