Abstract: Apparatus for guiding and steering pipe casing bored and pushed underground by an earth boring machine is disclosed which includes hinge assemblies pivotally connecting a steering head to a front casing. Each hinge assembly includes two pivots. A first pivot has a horizontal pivot axis and a second pivot has a vertical pivot axis. Preferably, the hinge assemblies are compound hinges so that the pivots are carried by a unitary hinge assembly. Actuators are provided which impart an actuation force on the steering head to rotate the steering head about the first and second pivot axes. One of the actuators is provided by slidably mounting one of the hinge assemblies so that the first and second pivot axes of that hinge assembly are compounded and moved unitarily. A second actuator is connected to the steering head to move the steering head about the first pivot axis while the hinge assembly slides to pivot the steering head about the second axis.

Abstract: An apparatus and method for steering pipe casing laid underground is disclosed which includes a steerable pipe jacking head attached to a forward pipe casing and pushed through the ground by a string of pipe casings from a pipe pushing or jacking machine at a station below or above the ground. A steering wedge which may be rotated to a desired steering position and then extended from the forward end of the pipe jacking head is disclosed which accurately steers the pipe jacking head in horizontal and vertical directions. An inclinometer is used to measure the vertical position of the pipe jacking head. A directional heading sensor which includes a toroidal fluxgate magnetometer with a free floating ring core is utilized to measure the horizontal position of the pipe jacking head. Horizontal and vertical position signals, and the rotational position of the steering wedge, are measured and transmitted as serial data to a computer where the signals are processed and displayed graphically on a display screen.

Abstract: Apparatus and method for a directional drilling system is disclosed wherein a concrete pit is poured at a reference entry angle in the earth so that a drilling platform cartridge inserted into the concrete pit is set at the desired entry angle. A frame, including elongated guide ways extending between ends of the platform cartridge, guides a carriage that advances a drill string through the earth at the reference angle. Preferably, a drilling head at the end of the drill string and the remainder of the drill string are rotated by a drive motor carried on the carriage. A drill bit and drill bit motor are mounted coaxially and eccentric with respect to the drilling head. The center axis of the drill bit and drill bit motor, and the center axis of the rotating drilling head are offset and define a known relationship.

Abstract: Apparatus for guiding and steering pipe casing bored and pushed underground by an earth boring machine is disclosed which includes hinge assemblies pivotally connecting a steering head to a front casing. Each hinge assembly includes two pivots. A first pivot has a horizontal pivot axis and a second pivot has a vertical pivot axis. Preferably, the hinge assemblies are compound hinges so that the pivots are carried by a unitary hinge assembly. Actuators are provided which impart an actuation force on the steering head to rotate the steering head about the first and second pivot axes. One of the actuators is provided by slidably mounting one of the hinge assemblies so that the first and second pivot axes of that hinge assembly are compounded and moved unitarily. A second actuator is connected to the steering head to move the steering head about the first pivot axis while the hinge assembly slides to pivot the steering head about the second axis.

Abstract: An earth boring tool for forming a bore underground at a desired percent of grade and a grade sensor (A) for sensing percent of grade as the bore is formed are disclosed. The earth boring tool includes a pipe casing (10) and cutting head (12). Sensor (A) includes dielectric fluid chambers (30b, 32b) formed by chamber plates (30, 32) and a sandwiched capacitor plate (34). Capacitors (34a, 34b) are contacted by the dielectric fluid in the chambers. A differential capacitance signal is produced as a fluid level (80) variably covers and uncovers capacitors (34a, 34b) to produce a varying differential output signal. The differential output signal is converted into a linearly changing percent grade signal (64) by a conversion circuit (44a). The percent of grade signal is displayed on a monitor (C) by which an operator may steer the casing to a desired grade.

Abstract: An earth boring tool control system for monitoring the spatial orientation of a remote boring tool (10) and adjusting the path thereof to maintain a predetermined course (22), is comprised of a vertical position detector (26) for determining the elevation of the tool relative to a desired course, including a sensor head member (32) in operative engagement with the tool for establishing a pressure head of fluid characteristic of the vertical disposition of the tool, a pressure sensor member (50) for sensing a differential pressure in response to variations in the height of the pressure head, and a fluid circuit (40, 44) communicating between the sensor head member and the pressure sensor member for transmitting any pressure variations to the sensor member; a horizontal position detector (28) for determining the azimuth of the tool relative to the course, including Hall generators (80, 82) in operative engagement with the tool for developing normalized output signals (90, 92) proportional to deviations in an am

Abstract: A control circuit for a windshield wiper motor which utilizes a plurality of infrared emitters that emit a chain of infrared pulses towards a plurality of infrared sensors. When rain passes between the infrared emitters and the infrared sensors, it will interrupt the flow of pulses therebetween. A control circuit senses the missed pulses and selectively energizes a low-speed, mid-speed and high-speed winding associated with the wiper motor for varying the speed of the windshield wipers. The device automatically controls the operation of the windshield wipers of a vehicle.

Abstract: Apparatus for monitoring the percent of grade and controlling machinery in response thereto is disclosed. A novel grade sensor A includes a reservoir 14 filled with a translucent fluid medium 30 to a predetermined level L. Grade sensor A is adapted for attachment to associated machinery such as casing head 50 of casing pipe 40 being simultaneously bored and pushed underground. A light emitting diode 18 transmits light through the fluid containing reservoir. Light detector 16 is located opposite the diode for detecting light intensity and has an output representing the intensity. Light intensity changes due to changes in the orientation of the sensor and inclination of the surface level of the fluid medium is used to indicate changes in percent of grade. Electrical means F converts output of detector 16 into a visual display of percent of grade change.