Abstract: A positioning device having a chamber having a chamber exhaust valve in a first end and a chamber fluid inlet in a second end; a piston disposed in a chamber between the first end and the second end, the piston being slidable in the valve chamber between a first position toward the first end and a second position toward the second end; the fluid communication opening having a smaller cross-section area than the chamber exhaust valve; and a piston biasing spring urging the piston toward the chamber second end and away from the chamber first end, the piston biasing spring responsive to a fluid pressure differential between the first and second chamber ends above and below a predetermined level to move the piston into the first and second positions, respectively.

Abstract: The invention relates to a drilling system. It includes, in combination, a drilling derrick by means of which a string of drill rods can be suspended from a hoist, a motorized drilling head at the end of the hoist, means for bringing a drill rod into position to be added to the drill string from a stack, a motor to drive the hoist, a reversible control for the said hoist motor, sensors for determining the state of the system, and a programmable robot to supply the set points to the hoist motor control according to signals furnished by the said system state sensors.

Abstract: In a hydraulic pile driver (10), the lifting cylinder (34) acting on the driving weight (12) has an attached position indicator (46, 50), which produces a signal corresponding to the momentary position of the piston rod (32) of the lifting cylinder (34). This signal is used for reversing a 4/3-valve, by which the two working chambers of the lifting cylinder can be connected to a pressure line or return line.

Abstract: The invention provides a low pressure shut off device contained within a pneumatic tool that senses the air pressure of an air stream supplied to a pneumatic motor and shuts off the air flow when the pressure falls below a predetermined level set to maintain consistent performance of the tool and to avoid damage to the tool or to the workpiece. The invention includes a throttle valve, a throttle piston that moves to open and close the valve, and a device for sensing the air pressure of the supply stream, holding the throttle valve open when the pressure is sufficient and closing it when the supply pressure is insufficient. The invention may also be used in combination with an air control system within a pneumatic tool such that the sensing device shuts off the flow of air to the air control system as well as the motor when the air control system pressure is insufficient.

Abstract: A hammer for driving a pile into the ground has a cylindrical barrel and an anvil sealed to an end of the barrel, a hammer piston mounted for reciprocation within the barrel towards and away from the anvil, hydraulic cylinders to lift the hammer piston away from the anvil, and a switch, responsive to an increase in fluid pressure in the space between the hammer piston and the anvil, to activate the lift means. The invention includes a method of driving a pile into the ground, in which the pile-driving impact is transmitted to the pile via a confined quantity of hydraulic fluid and the weight by which the impact is applied is lifted, to a position from which to apply a further impact, in response to an increase in pressure in the hydraulic fluid.

Abstract: A method for optimizing percussive drilling, especially rock drilling, in which method the operation of the drilling device is adjusted for a desired drilling result to be obtained. According to the invention, a stress wave created in a drill rod as a result of a stroke is measured and the drilling device is adjusted on the basis of the measured stress wave. The adjusting is carried out e.g. by means of the damping rate or the spectrum of the measured stress wave or the shape of the stress wave and/or the energy fed by the different portions thereof.

Abstract: An apparatus for abrasive cleaning comprising a truck adapted to run on the surface to be cleaned and at least one abrasive cleaner supported by a supporting mechanism on the truck and limitedly movable toward or away from the surface, the abrasive cleaner having an abrasive cleaning tool at its lower end, said or each abrasive cleaner being supported by the supporting mechanism so as to be limitedly tiltable in every direction with respect to an axis approximately perpendicular to the surface, the supporting mechanism being provided with a compression spring for biasing the abrasive cleaner away from the surface. Even when the surface to be cleaned has an undulation, the abrasive cleaner tilts with respect to the axis to hold the cleaning tool in uniform contact with the surface and assure a stable and uniform cleaning operation.

Abstract: A nut runner for tightening screwed objects comprising: a driving motor, a driving shaft to be coupled to the screwed objects for driving the same, a reduction gear mechanism provided for transferring the revolution power of the driving motor to the driving shaft, a torque for detecting a torque applied to the driving shaft, and a control circuit for controlling the driving motor by the use of the detected output of the torque detector. In accordance with the present invention, a two-phase induction motor is employed as the driving motor.

Abstract: A torque transducing system for an impact tool such as an impact wrench incorporates a housing, bearings in the housing, a rotatable shaft journalled in the bearings, the shaft having a torque receiving input end and an output end supplying torque for a workpiece, a torque transducing gauge on the shaft intermediate the input and the output end for providing a first signal responsive to torque, circuitry on the rotatable shaft for modulating the first signal to a second signal, structure on the shaft for supplying current to the gauge and modulating circuitry and additional structure for transmitting the second signal, further structure on the housing for receiving the transmitted second signal, and circuitry for converting the second received signal to provide an output indicative of torque.

Abstract: A leader angle control device comprises two inclinometers for measuring inclination of a leader in two directions, an arithmetic unit for calculating the length of two backstays which support the leader based on the detected inclination of the leader and a control unit for controlling backstay cylinder driving oil.In one embodiment of the leader angle control device, the leader angle is controlled manually to a certain extent before automatic control takes place, whereby the acceleration applied to the leader at the time of shift to automatic control is kept small and then gradually increases, thus enabling smooth control of the inclination of the leader.

Abstract: A quick changeover hydraulic circuit for use in an auger drive mode or percussion hammer mode, controllable in each mode by the same flow regulator. The circuit comprises a first branch circuit which powers a first auxiliary hydraulic powered device and a hydraulic motor for drill steel rotation. A second branch circuit powers a hydraulic percussion motor for a drill steel hammer or a rotary hydraulic motor for an auger, only one of which is in the circuit at one time. An interbranch circuit comprises a priority flow divider which distributes flow. In a first mode with the percussion motor for the drill steel hammer connected into the second branch the flow is delivered to the steel rotation motor and the first auxiliary device. In a second mode with the auger motor connected into the second branch, combined flow from both branches is delivered to the auger motor.

Abstract: In a pivotally mounted rock drill boom and feed bar apparatus, the pivots of the boom and the feed bar positioner include angle sensors comprising cam actuated fluid pressure regulating valves. The pressure regulating valves are disposed in a control circuit which includes a pilot pressure fluid actuated control valve which senses an unbalanced pressure signal generated by the sensor connected to the boom pivot in response to movement of the boom about said pivot. The control valve responds to the unbalanced pressure condition by valving fluid to the feed bar positioner actuator to maintain the feed bar in a predetermined directional attitude. The angle sensor mounted on the boom pivot may be adjusted independent of movement of the boom to cause a change in the directional attitude of the feed bar as desired.

Abstract: A circuit or control arrangement for an adjusting drive of a press ram of a high-speed cutting press which includes top and bottom dies respectively attached to the press ram and a platen of the press with the top die being adapted to dip or penetrate during a cutting process into the bottom die. An arrangement is provided for maintaining the depth of penetration of the upper die means into the lower die means to a constant value in dependence upon an operating condition of the high-speed cutting press. The maintaining arrangement may include at least one limit switch operatively connected with an oscillator stage which provides adjusting signals to the drive motor. In lieu of a limit switch, a cutting force measuring sensor member may be interconnected with an evaluator circuit and the oscillator means so as to control the drive motor.

Abstract: In a pneumatic nail driver, compressed air drives a working piston in the driving direction within a working cylinder. An inlet valve controls the flow of compressed air into the working cylinder. A sensing element mounted on the front end of the driver moves opposite to the driving direction when it is pressed against the receiving material for the nail. The sensing element pivots a shift lever which in turn moves a safety valve for controlling in one position the flow of compressed air to the control space associated with the inlet valve and in another position to connect the control space to the ambient atmosphere.

Abstract: A servo system is presented for controlling the angular attitude of machine units pivotally mounted on an outlying boom frame. Said system is applicable to rock drilling machines, breakers, loading scoops and forks, working platforms, manipulator booms, and the like. The system includes a directional control valve for governing the positioning motor of the machine unit. Under full working pressure the directional valve in itself provides automatic attitude control of the machine unit. To this end the directional valve is provided with a feedback position, in which the pressure fluid communications to the positioning motor are cut off and furthermore has a syngonous (uniangular) relationship on the one hand to the actual angle value of the machine unit with one of its valve elements and on the other to a selective set angle value with its other valve element.

Abstract: Disclosed is a method for marking out drill holes in accordance with a predetermined drill hole pattern. A direction reference beam (c) is projected in a direction defining the direction of the tunnel and part of a beam (e) is deflected from the reference beam, the part of the beam is passed to a beam derivating means (d.sub.2) by means of which the part beam is directed in accordance with a predetermined drill hole pattern onto the rock surface (4) to present thereon images of the part beam at locations of intended drill holes. Correspondingly, a device for executing said method comprises means (d.sub.1) for deflecting at least part of a direction reference light beam (c) to form part of a beam (e), and means (d.sub.2) to direct the part of the beam onto locations of drilling holes for explosives in accordacne with a predetermined pattern.

Abstract: A rock drilling method according to which the drill is subjected to successive axial strikes and is rotated around its longitudinal axis. The direction of rotation is repeatedly reversed after the drill has rotated at least one revolution in one direction.

Abstract: An elongated rock drilling apparatus is swingable by positioning power means. Set values of inclination and direction of the rock drilling apparatus are set by prepositioning a first pendulum device relative to the rock drilling apparatus. According to one aspect of the invention the actual values of the inclination and direction of the rock drilling apparatus in perpendicular directions are sensed by means of said first pendulum device. According to another aspect of the invention the actual values of the inclination and direction of the rock drilling apparatus are sensed by means of a second pendulum device. Means are provided for automatically bringing the rock drilling apparatus to a position in which set and actual values of inclination and direction coincide.

Abstract: In a pivotally mounted rock drill boom and feed bar apparatus the boom and the feed bar positioner include angle sensors comprising cam actuated fluid pressure regulating valves. The pressure regulating valves are disposed in a control circuit which includes a pilot pressure fluid actuated control valve which senses an unbalanced pressure signal generated by one of the sensors in response to pivotal movement of the boom. The control valve responds to the unbalanced pressure condition by valving pressure fluid to the feed bar positioner actuator to maintain the feed bar in a predetermined directional attitude. The angle sensor responsive to pivotal movement of the boom may be adjusted independent of movement of the boom to cause a change in the directional attitude of the feed bar as desired.

Abstract: An oil drilling rig includes a racker, a power tongs, a drawworks having a motor and a brake, and a general purpose programmable digital computer associated with each to sequentially initiate the operation thereof. Closed-loop control systems for the drawworks motor and drawworks brake are included to provide control signals to a motor drive and to a brake actuator.

Abstract: In a drill boom pivotally supporting a rock drilling apparatus, hydraulic parallel motion means is provided which includes a hydraulic pilot cylinder for sensing the setting of the elevation angle of the drill boom. During elevating of the drill boom the hydraulic pilot cylinder is furthermore used as an additional elevating cylinder.

Abstract: Switch means on the frame of a forging device senses when the ram and piston enter a first zone of a pneumatic cushion during retraction to initiate timing. If a predetermined time has expired before the ram leaves the first zone, the fluid inlet valve is opened. If not, switch means senses when the ram and piston enter a second zone to initiate a second timing. If a second predetermined time expires before the ram leaves the second zone, the fluid inlet valve is opened. If not, switch means senses when the ram and piston enter a third zone, and after a predetermined time the fluid inlet valve is opened. Thus, by sensing ram position and measuring time ram remains within each zone, the effective upward velocity (distance/time) is measured and adaptive controls applied.

Abstract: In a method of regulating the supply of driving-medium per stroke cycle to a pile-driving rammer the driving-medium supply per stroke cycle is adjusted for driving piles into the ground in the shortest time in dependence upon the value, measured by at least one scanner, of the result of at least two preceding strokes of the rammer and more in accordance with the driving-medium supply adjusted during the stroke which gave the better result.In order to improve the energy transfer from a diesel hammer upon the pile apart from a basic fuel per combustion cycle at least one substance affecting the combustion velocity is supplied to the Diesel hammer in accordance with the pile-driving operation.

Abstract: A gas cushion impact cap, used in connection with pile driving, is connected to an external pressure chamber holding an additional volume of gas, whereby there will be no appreciable change in the gas pressure during the impact. The gas pressure is primarily determined by varying the volume of a liquid contained in the pressure chamber, in response to the resistance met by the pile while penetrating the ground. The impact cap may be pre-loaded during an upwards movement, the pre-load being released upon the impact, to throw the hammer upwards again.

Abstract: In a drill boom pivotally supporting a rock drilling apparatus, hydraulic parallel motion means is provided which includes a hydraulic pilot cylinder for sensing the setting of the elevation angle of the drill boom. During elevating of the drill boom the hydraulic pilot cylinder is furthermore used as an additional elevating cylinder.

Abstract: An automatic alignment control system for an earth boring rig utilizes sensor means on the drilling mast for actuating switches connected to power controls. The sensor means reacts to misalignment of the drilling mast vertical axes to close appropriate switches which in turn generate signals to power means which are arranged to shift the mast axes in the appropriate direction for proper vertical alignment.

Abstract: In a hydraulic percussion rock drill the operation of the working fluid distributing valve is controlled to effect a variation in percussive blow energy and blow frequency by varying the piston hammer stroke. Actuation of the distributing valve is controlled by a remote controlled hydraulically actuated pressure control valve interposed in a fluid passage which conducts hydraulic fluid from the hammer bore to actuate the distributing valve. Substantially infinite variation of hammer impact blow energy between high and low limits provides for selecting the maximum penetration rate of the drill for any type of rock conditions. The hydraulic rock drill is connected to a source of hydraulic fluid supplied to the drill at substantially constant fluid power by a variable displacement constant power hydraulic pump.

Abstract: A rotary power drive is provided for delivering a substantially constant horsepower over a wide speed range in one direction of rotation comprising two or more constant displacement hydraulic motive means operatively associated with a shaft to be driven thereby, an overrunning clutch operatively interposed between at least one of such motive means and said shaft, and means for supplying hydraulic drive fluid to such motive means in different combinations over different shaft speed ranges to provide a multiple displacement hydraulic motor drive apparatus.

Abstract: A portable earth boring machine for the horizontal boring of shafts and the insertion of pipeline casing sections in installations where excavation from the surface is undesirable. The machine is characterized by a steering head particularly adapted for rock drilling operations which head is positioned at the front of the casing with such steering head being automatically controlled so as to directionally control the direction of extension of the pipeline as the drilling operation progresses.

Abstract: A portable earth boring machine for the horizontal boring of shafts and the insertion of pipeline casing sections in installations where excavation from the surface is undesirable. The machine is characterized by a steering head positioned at the front of the casings which steering head is automatically controlled so as to directionally control the direction of extension of the pipeline as the drilling operation progresses.