A concrete anchor capable of resisting large loads while requiring minimal embedment depth. The system includes a concrete structure including a cylindrical opening in the concrete surface thereof. The system also uses an anchor which includes a sleeve and a plug. The sleeve includes at least two legs extending toward a first end of the sleeve. The plug includes an increasing diameter portion disposed toward a first end of the plug. The plug includes a locking opening. After installation, legs of the sleeve extend radially outward past the wall and the increasing diameter portion prevents inward movement of the legs to lock the sleeve and the plug in turn in the concrete cylindrical opening. Furthermore, dynamic loading on the plug via the locking opening when the anchor is in use generates a dynamic radially outward force on the legs to secure the anchor in the concrete hole.

A method for creating a weep hole is disclosed. The weep hole is drilled in an uncured, concrete, hollow core structural component having one or more external surfaces and one or more internal surfaces. The weep hole is drilled using a drilling apparatus comprising a drill, a rotating drill bit with an internal fluid passageway, a power source, and a pressurized fluid source. Loose, uncured concrete material deposited near the weep hole on the one or more internal surface as a result of drilling the weep hole is removed by releasing pressurized fluid which flows from the pressurized fluid source, through the drill and the rotating drill bit.

Methods and devices relating to loose debris chip shielding for dust free tile removal and ordinary tile removal projects. During the tile removal process, a chipping hammer powers a chipping hammer blade that breaks up tiles into pieces. The larger, heavier pieces are simply pushed away, but smaller debris chips break off with enough force to send them flying up in the air and in different directions landing in undesirable locations. The methods and devices herein protect equipment, environments, and individuals from damage caused by loose debris chips during tile removal. A shield with several degrees of freedom moves freely in response to chipping hammer vibrations and blocks loose flying debris chips, deflecting them toward the ground.

A control method for a borehole flushing module (2) for a chiseling tool (5), includes the steps: Providing fine-grain particles in a dispenser (31); ascertaining a material (M) at a location processed by the tool (5) with the aid of a material detector (37); and introducing fine-grain particles at the location of the substrate processed by the tool (5) when the material detector (37) ascertains an iron-containing material (M2).

A concrete anchor capable of resisting large loads while requiring minimal embedment depth. The system includes a concrete structure including a cylindrical opening in the concrete surface thereof. The system also uses an anchor which includes a sleeve and a plug. The sleeve includes at least two legs extending toward a first end of the sleeve. The plug includes an increasing diameter portion disposed toward a first end of the plug. The plug includes a locking opening. After installation, legs of the sleeve extend radially outward past the wall and the increasing diameter portion prevents inward movement of the legs to lock the sleeve and the plug in turn in the concrete cylindrical opening. Furthermore, dynamic loading on the plug via the locking opening when the anchor is in use generates a dynamic radially outward force on the legs to secure the anchor in the concrete hole.

Provided is a two-piston hydraulic striking device that has stable operativity. This two-piston hydraulic striking device includes two striking mechanisms for striking one transfer member. Each striking mechanism has a pressure receiving area ratio between the front and rear of a piston thereof set in such a way that the two striking mechanisms have the same cycle time.

Provided is a hydraulic striking device in which a reverse operation circuit and a forward operation circuit can switch connection states to a high pressure circuit and a low pressure circuit by means of an operation switching valve. Further, the hydraulic striking device is configured to be selectable between a reverse operation mode or a forward operation mode by operating the operation switching valve. A high/low pressure switching portion is provided with a shortening portion for reducing the time required for high/low pressure switching operation in piston front and rear chambers in association with retraction of a valve to be shorter than the time required for high/low pressure switching operation in the piston front and rear chambers in association with advancement of the valve.

A hydraulic hammering device is capable of sufficiently transmitting blow energy to bedrock while further strengthening cushioning action and suppressing damage to equipment. The device includes a pushing piston disposed behind a transmission member and having a smaller propulsive force than that of a main body, a damping piston positioned behind the pushing piston to slide reciprocally forwards and backwards and having a greater propulsive force than that of the main body, a direction-restrictor in a high-pressure circuit between pushing and damping chambers, to which hydraulic fluid is supplied for providing the pistons with propulsive forces, and a fluid supply source. The direction-restrictor restricts an outflow from the chambers side to the fluid supply source side while allowing fluid inflow from the fluid supply source side to the chambers and the pushing chamber sides. A throttle in a drain circuit discharges leaked fluid from a sliding contact location to a tank.

A power tool including an impact tool, a body and an actuator. The actuator is operable to move the body along an operational axis from an impact position, at which the body is operable to transfer impact energy to a head end of the impact tool, to a retracted position spaced apart from the impact position along the operational axis.

An electric power tool is configured to rotate an attachment about a Z-axis. The electric power tool includes a three-axes acceleration sensor and an acceleration detection circuit. The acceleration detection circuit calculates an angular acceleration about the Z-axis based on an input signal from the three-axes acceleration sensor. The acceleration detection circuit calculates a change in an angular velocity based on integrating the angular acceleration for a most recent period. The acceleration detection circuit determines a Z-axis angular velocity about the Z-axis, without adding a previous change in the angular velocity from before the most recent period, as equal to the change in angular velocity. The acceleration detection circuit detects a twisted-motion of the electric power tool based on the Z-axis angular velocity.