Abstract: A power tool and method of detecting impacts of a power tool that includes a motor driving a hammer to impact an anvil. A motor control unit is configured to determine a motor characteristic indicative of a speed of the motor. When the motor characteristic indicates that the speed of the motor is below a speed threshold, the motor control unit employs an acceleration-based technique to detect a first impact based on a change in motor acceleration and generate a first impact indication in response to detecting the first impact. When the motor characteristic indicates that the speed is above the speed threshold, the motor control unit employs a time-based technique to detect a second impact based on an elapsed time and generates a second impact indication in response to detecting the second impact.

Abstract: A drilling assembly includes a hydraulic amplifier assembly, a driver, a bearing housing, and a shaft. The hydraulic amplifier assembly is configured to increase a pressure of a drilling fluid so as to produce a pressurized drilling fluid. The driver is driven by the pressure of the drilling fluid and is configured to rotate a drill bit. The bearing housing is coupled to the driver. The shaft extends through the bearing housing and is configured to be coupled to the drill bit. The shaft is driven to rotate by the driver. The hydraulic amplifier is configured to deliver the pressurized drilling fluid to the drill bit.

Abstract: A method for maintaining a penetration rate of a drilling operation, where the drilling operation is carried out by a drilling rig having a hammer drill apparatus. A reference penetration rate for the hammer drill bit is chosen. A starting depth of cut is computed from the reference penetration rate, the measured hammer frequency, and the drill bit parameters. The system measures the actual penetration rate of the drill bit and computes an actual depth of cut. From the actual depth of cut a target bit rotation speed is computed. The target rotation speed is compared to the actual rotation speed, and the rotation speed is adjusted up or down to set the bit rotation speed at a value that will maintain the target rotation speed, notwithstanding changes in hammer frequency or ground conditions.

Abstract: A fluid-powered linear motor with rotary pistons is disclosed. An application is for a downhole motor but it could be used in other applications. Rotational pistons provide increased torque generation as the torque generated is proportional to motor length. Since downhole drills are long (generally up to a maximum length of 30 ft.), a high-torque motor can be produced using this method. A pressurized fluid is used to drive the piston assemblies to produce bit shaft power. This concept employs rotary pistons and a mechanical rectifier to convert the rotational reciprocation produced by a reciprocating rotational piston into continuous rotary motion. Integration of synthetic diamond bearing assemblies into the motor allows for reduced friction and abrasive drilling fluid compatibility.

Abstract: A fluid-powered linear motor with rotary pistons is disclosed. An application is for a downhole motor but it could be used in other applications. Rotational pistons provide increased torque generation as the torque generated is proportional to motor length. Since downhole drills are long (generally up to a maximum length of 30 ft.), a high-torque motor can be produced using this method. A pressurized fluid is used to drive the piston assemblies to produce bit shaft power. This concept employs rotary pistons and a mechanical rectifier to convert the rotational reciprocation produced by a reciprocating rotational piston into continuous rotary motion.

Abstract: An oil pulse tool includes a motor, an oil pulse unit, an output shaft on which a front end tool is attached, a torque detecting sensor for detecting generation of an impact torque, and an operating portion configured to detect a time period between a first impact torque detected by the torque detecting sensor and a second impact torque detected by the torque detecting sensor. The second impact torque is smaller than the first impact torque. The operating portion carries out a notification when the time period between the first impact torque and the second impact torque is less than a predetermined evaluation value for the time period between the first impact torque and the second impact torque.

Abstract: A pneumatic impulse wrench for tightening screw joints includes a housing with a pressure air inlet passage, an exhaust air outlet passage, a rotation motor, a hydraulic impulse generator, and is connected to a stationary programmable control unit. The impulse wrench also includes a torque indicating mechanism connected to the control unit for feeding back electric signals responsive to the output torque of the wrench, an electromagnetically activated inlet valve arranged in the air inlet passage, and an electromagnetically activated exhaust valve which controls the exhaust air flow from the motor. The exhaust valve is a proportional valve activated by a linearly operated electromagnetic actuator and arranged to continuously adapt the exhaust air flow and, hence, the motor power to the characteristics of the actual screw joint being tightened in response to feed back signals from the torque indicating mechanism and in accordance with a programmed tightening strategy.

Abstract: An arrangement and a method for controlling at least one drill parameter when drilling in rock with a rock drill, comprising an impulse-generating device arranged to induce shock waves in a tool acting against the rock with a percussive force generated via a shock wave-generating pressure. The arrangement and method comprises a control system for determining a first parameter value representing the damping pressure, determining a second parameter value representing the rotation pressure of a drill bit, determining a deviation between the second parameter value and a rotation pressure reference value, determining a parameter reference value depending on the deviation, and regulating the percussion pressure based on a function of the deviation and the parameter reference value.

Abstract: A method of estimating the available grip margin of a tire of a vehicle rolling on a ground involves: estimating a quantity Rslip ca, i.e., the ratio of the slip contact area and the total contact area of the tire on the ground; determining, in a signal processing unit, the grip potential used P?,used and/or the available grip margin of the tire P?,avail from the quantity and pre-established data corresponding to the type of the tire, where P?,avail=1?P?,used; and recording in a memory the grip potential used and/or the available grip margin of the tire.

Abstract: An electric power tool is provided with: a motor; a hydraulic pressure generator driven by the motor and configured to generate a plurality of impacts in one revolution thereof; an impact angle detector configured to detect an impact angle in one impact of the hydraulic pressure generator; an electric current detector configured to detect an electric current applied to the motor; a determination unit configured to determine an impact failure based on the impact angle and the electric current detected by the impact angle detector and the electric current detector; and a rotation controller configured to decrease a rotation speed of the motor when the determination unit determines the impact failure.

Abstract: An improved pneumatic device includes a body having a hollow cavity, defining an X axis and having a first end and a second end. The body includes a movable cylinder, a nail-firing piston rod and at least one exhaust hole. The movable cylinder and the nail-firing piston rod reciprocate along the X axis in the body by performing a forward stroke to the second end, and a return stroke back to the first end. The movable cylinder presents an open status when completing the forward stroke and presents a closed status when completing the return stroke. The movable cylinder has an exhaust hole and an exhaust valve disposed at an outer periphery thereof. When the nail-firing piston rod has not completed the return stroke yet and the cylinder is in the closed status, an exhaust channel is thereby formed to facilitate exhausting of air.

Abstract: An electric power tool is provided with: a motor; a hydraulic pressure generator driven by the motor and configured to generate a plurality of impacts in one revolution thereof; an impact angle detector configured to detect an impact angle in one impact of the hydraulic pressure generator; an electric current detector configured to detect an electric current applied to the motor; a determination unit configured to determine an impact failure based on the impact angle and the electric current detected by the impact angle detector and the electric current detector; and a rotation controller configured to decrease a rotation speed of the motor when the determination unit determines the impact failure.

Abstract: A method, arrangement and valve for controlling rock drilling. In the method, a pressure difference acting across a rotation motor is used to regulate a separate feed regulating valve, which, on the basis of this, regulates control pressures of a feed control valve. The arrangement comprises a separate feed regulating valve, which, under the influence of the pressure difference acting across the rotation motor, regulates control pressures of a feed control valve. The valve comprises a separate retarding element, which slows down the returning of a spool of the valve to the normal position, if the spool has moved away from its normal position under the influence of the pressure difference acting across the rotation motor.

Abstract: A hydraulic breaker hammer includes a housing with a longitudinal bore, a cylinder sleeve, and a rear end cover engaging the cylinder sleeve. A hammer piston is reciprocally powered in the cylinder sleeve for delivering blows to a working implement inserted in a guide sleeve at the front end of the bore. The guide sleeve is provided with radial openings for communication of lubricant from a lubricant supply passage in the housing to the inside of the guide sleeve and the guide sleeve is provided with external seal rings forming annular compartments located between the lubricant supply passage and the radial openings for spreading lubricant on the outside surface of the guide sleeve.

Abstract: The invention relates to a rock drilling arrangement and a method and program for controlling rock drilling on the basis of specific energy consumption. The specific energy of drilling is the quantity of energy used per a unit of length of the drilled hole. Not only the used impact energy, but also the energy used by at least one other sub-process is taken into account when determining the specific energy. Rotation energy is typically included, but feeding energy and flushing energy can also be considered. Drilling variables are adjusted so that the specific energy is of a predetermined size.

Abstract: A device for supplying hydraulic power to a rotary apparatus for percussive drilling (2) whereof the tool (3) is driven in one direction or another and subjected to the action of an impact device (6) acting independently of the rotation, of a hydraulic device (9) with forward movement enabling the tool to generate a pressure force on the ground, and optionally of a suction device (14) for the drilling dusts, driven by a hydraulic motor, the various hydraulic actuating elements being driven from a hydraulic liquid source under pressure through a hydraulic flow divider (16), a set of distributors (17, 18, 19, 20) and an assembly of branch pipes outside the apparatus, such as hose pipes. The device includes a branch pipe external to the apparatus (24) for communicating the return branch pipe (22) of the hydraulic device (4) driving the tool in rotation and the supply line (23) of the impact device (6), to add to the supply rate of the impact device the return flow rate of the rotation driving device.

Abstract: A rock drilling device has a feed beam (1) and a rock drilling machine (2) movable along the feed beam. The rock drilling machine is fed along the feed beam (1) by a feed line (7), which is routed over a sheave (6) arranged at the movable end (5) of a pressure medium cylinder (3). A further line (8) is arranged between two points (9, 10) which are fixed relative to the movable end of the pressure medium cylinder. The further line (8) is connected to a measuring device (11) which is fixed to the feed beam (1) for measuring displacement of the rock drilling machine (2) along the feed beam.

Abstract: The invention concerns an arrangement for controlling a hydraulic rock drilling device. The arrangement includes a pressure ratio valve that is used for adjusting the relation between the pressures in the pressure channel leading to the percussion device and/or another actuator, such as a shank stabilizer, and the pressure channel leading to the feed mechanism. The pressure ratio valve is arranged to keep the relation between the pressures of the actuator and the feed mechanism constant over the normal drilling range.

Abstract: A damper pressure control apparatus for a hydraulic rock drill is automatically adjustable of damper pressure to be applied to a damping piston depending upon a thrust of a rock drill body and makes damping function and floating function effective even when thrust of hydraulic rock drill is varied. The damper control apparatus is thus provides a damper pressure control for controlling the damper pressure (DPpr) to be applied to a damping piston (16, 17) from a hydraulic pressure source (21) based on the frontward thrust (F1) acting on the hydraulic rock drill body 1.

Abstract: A hydraulic circuit (10) is disclosed for use in controlling a horizontal boring machine which requires hydraulic fluid under pressure for rotating a drill bit or backreamer through a rotation circuit and hydraulic fluid under pressure for thrusting the drill bit or backreamer within the bore hole through a thrust circuit. Pressures from both the thrust circuit and control circuit are combined through restrictors in a mixing zone or area (26). The control port of a diversion valve (32) is connected to mixing zone (26). When the combined pressure in the mixing zone exceeds the adjustable spring bias on the diversion valve, the diversion valve will open, diverting fluid from the thrust circuit to a low pressure zone. This will cause a reduction in the pressure in the rotation circuit as well. The reduction of both pressures will reduce the combined pressure in the mixing zone (26), causing the diversion valve to close and the pressures to increase.

Abstract: An apparatus includes a feed cylinder having a first end port and a second end port. A feed cylinder is located within the feed cylinder and is movable in a drive direction in response to fluid pressure applied to the first end port, and is movable in a return direction in response to fluid pressure applied to the second end port. A feed pump selectively displaces fluid between the first and the second end ports. A variable overcenter device controls fluid pressure offset, independent of the feed pump, between the first end port and the second end port. An adjustment device automatically adjusts the variable overcenter device during travel of the feed cylinder in the drive direction to a value corresponding to an amount of force required to displace the feed cylinder in the return direction.

Abstract: Apparatus for manipulating a tool which is particularly suited for use in drilling and inserting bolts into thin seams of mine workings. The apparatus (100) comprises a reaction support member (4) to support the tool, a chuck (1) for holding the tool, mounting member (12) in which the chuck (1) is mounted, and a lever linkage (13) connected between the mounting member (12) and the support member (4). The lever linkage (13) comprises parallel chuck orienting members (5, 10) connecting the mounting member to a control member (9), said control member being adapted to manipulate the chuck orienting members and to control the orientation of the chuck. The lever linkage further comprises first and second links (14, 15) each having first and second ends. The links are pivotally attached to each other at the first ends thereof. The first link is pivotally attached at the second end thereof to the mounting member and the second link is pivotally attached at the second end thereof to the support member.

Abstract: In a method of and device for adjusting the feed movement of a drill rod for drilling a rock, the drill rod is rotated by a pressure-medium-operated rotary motor and fed in a drilling direction and in the opposite direction by a pressure-medium-operated feed motor. A pressure change on the pressure side of the rotary motor due to a change in the rotation resistance on the rotary motor acts oppositely on the pressure and outlet sides of the feed motor toward reversing the feed force of the feed motor, i.e. in inverse and direct dependence on the pressure change, respectively. The pressures on the pressure side and the outlet side of the feed motor are, therefore, controlled so that, when the pressure on one side increases because of the pressure change, the pressure on the other side decreases and vice versa.

Abstract: A method and apparatus for controlling the rotational torque of a drill bit powered by a downhole motor. The downhole motor is suspended from a hydraulic ram at the lower end of a string of drill pipe. A torque sensor detects the reactive torque in the downhole motor during drilling. In response to the detected torque level, pressurized drilling fluid from the downhole motor is provided to the hydraulic ram thereby varying the weight applied to the drill bit in order to maintain a constant torque level.

Abstract: A rock drilling apparatus for drilling with high pressure hydraulic jet including a rock drill body (11), a drill tool (12) coupled to said body (11) and a feeding device (15) with a motor (16) for feeding said body and tool to and fro the working face. The drilling tool (12) has an inner rotating tube (40) with a high pressure nozzle body (41) at the nose thereof and an outer tube (42) surrounding said inner tube (40). Said outer tube (42) is provided with a hard metal collar (61) at the front end for protecting the nozzle body (41) and for calibration of the drill hole size. A sensing device including a pressure operated switch 73 and an adjustable time relay (83) is adapted for sensing the feed resistance met by said collar (61) and causing said feed motor (16) to retract said drill body (11) and tool (12) when a preset value of the resistance is exceeded.

Abstract: This invention relates to a process of automatic drilling with an in-hole motor particularly of the turbine type. The invention relates to apparatus and process by which the draw works responsive to a signal generated by an in-hole tachometer in the form of a train of pulses of period responsive to the rpm of the motor is sensed by a pressure transducer which generates a signal which is responsive to the rpm of the motor telemetrically in the form of the train of pulses. The signal is converted into a pressure applied to the brake of the draw works driven to hold the tension on the drilling lines and thus holds the rpm of the motor substantially consistant. In the best mode disclosed, this is accomplished by producing an electrical signal responsive to the train of pulses and storing said signal between pulses and generating a pneumatic pressure responsive to the stored signal and applying a force to said driver responsive to said last named pressure.

Abstract: A rock drill having a hydraulic system for controlling striking, rotating and advancing movements of a drilling rod. The advancing or forward feeding conduit for a feed actuator is provided with a relief valve which is responsive to the pressure in the positive rotating conduit for a rotary actuator so that the pressure in the forward feeding conduit is relieved to weaken the advancing force when the load on the rotary actuator is increased. A further relief valve is also provided for relieving the pressure in the striker conduit to weaken the striking force.

Abstract: A excavating machine for excavating rock and minerals from a working face having a carriage with a boom support. A cutter carrying boom is moveably supported by the boom support, and a means is provided for moving the boom relative to the carriage. A drive means is included with a sensing control means for controlling the movement of the boom relative to the carriage. The sensing control means senses a parameter proportional to the reaction cutting force on the cutter. Control over the movement of the boom is provided in two alternative modes of control. A rate mode control for controlling the machine in accordance with a preselected rate of the output of the drive means is provided, as well as a load mode control in which the movement of the boom is controlled maintaining the reaction cutting force exerted by the cutter substantially at or below a certain value.

Abstract: A rock drill feed system moves a drill toward and away from a wall with a reciprocating hydraulic motor powered by pressurized fluid. The pressurized fluid is controlled by a movable control valve that has a first position obtained manually to move the drill inwardly to drill, a second position obtained automatically when the drill has completed drilling, and a third position obtained automatically when the drill has been completely withdrawn. The sensing of the location of the drill to position the control valve is accomplished by measuring the pressure and flow rate of the hydraulic fluid delivered to the motor with pressure responsive switches. When the pressure exceeds a preselected level and the flow rate drops below a preselected level, the two pressure switches close to produce a signal that moves the valve to another position.

Abstract: A control system for a hydraulic percussion rock drill and feed mechanism including a single constant power hydraulic pump for supplying pressure fluid to operate the feed mechanism, drill stem rotation motor, and the percussion hammer. The drill feed, rotation and percussion functions are controlled by individual manually actuated pressure compensated valves. Fluid pressure to the feed mechanism is controllable at one of two selectable pressures and is automatically reduced if fluid pressure to the drill stem rotation motor exceeds a predetermined limit. The drill percussion blow intensity and frequency is controlled by a mechanism responsive to a fluid pressure signal which is automatically operated to provide for a high blow frequency and low blow intensity operating mode when the drill is retracted away from the workface. The constant power hydraulic pump is provided with a control which will adjust the pump output to a partial displacement setting when the drill is being retracted away from the workface.

Abstract: A searching method for optimizing the rate of penetration of a drill into a given medium based upon the two drilling parameters of thrust and speed of revolution. Preset base values of both parameters are input into the drilling control mechanism at the start of the process. Thereafter, based upon readings from an automatic penetration rate calculator, incremental changes are automatically made to one of the parameters, the other being held constant, until a maximized rate of penetration is established. Subsequently, the other parameter, previously held constant, is changed until a new maximized penetration rate is found. This optimized penetration rate searching is continuously and automatically effected until the drilling process is completed. The method additionally provides for the allowance of a wait period between successive incremental changes for accommodating response times of the system as well as instabilities which may occur as the result of nonlinear process dynamics.

Abstract: An apparatus employed in the searching of the optimized rate of penetration of a drill into a given medium based upon the two drilling parameters of thrust and speed of revolution. Preset base values of both parameters are input into the drilling control mechanism at the start of drilling. Thereafter, based upon readings from an automatic penetration rate calculator, the apparatus effects automatic incremental changes to one of the parameters, the other being held constant, until a maximized rate of penetration is established. Subsequently, the other parameter, previously held constant, is changed until a new maximized penetration rate is found. This optimized penetration rate searching is continuously and automatically effected until the drilling process is completed. The apparatus additionally provides for the allowance of a wait period between successive incremental changes for accommodating response times of the system as well as instabilities which may occur as the result of nonlinear process dynamics.

Abstract: A hydraulic drilling machine for cutting into rock formations and the like. The machine has a rotating drill rod with a bit at one end and a rotary hydraulic drive motor at the other end. The drill rod is supported on a carriage adapted for linear travel to advance the rotating bit into the rock formation. The carriage is extended and retracted by means of a hydraulic feed motor. The rotary hydraulic motor and the hydraulic feed motor are connected in series in the hydraulic operating system so that when rotation resistance increases accompanied by a greater pressure drop across the rotary hydraulic motor, there is a consequent decrease in the force exerted by the hydraulic feed motor in order to avoid jamming of the drill bit.

Abstract: A hydraulic circuit (10) is disclosed for use in controlling a horizontal boring machine which requires hydraulic fluid under pressure for rotating a drill bit or backreamer through a rotation circuit and hydraulic fluid under pressure for thrusting the drill bit or backreamer within the bore hole through a thrust circuit. Pressures from both the thrust circuit and control circuit are combined through restrictors in a mixing zone or area (26). The control port of a diversion valve (32) is connected to mixing zone (26). When the combined pressure in the mixing zone exceeds the adjustable spring bias on the diversion valve, the diversion valve will open, diverting fluid from the thrust circuit to a low pressure zone. This will cause a reduction in the pressure in the rotation circuit as well. The reduction of both pressures will reduce the combined pressure in the mixing zone (26), causing the diversion valve to close and the pressures to increase.