A two-step auto stroke hydraulic breaker includes a cylinder including a high-low pressure chamber, a high pressure chamber, and a pressure converting chamber including a pilot port, a high pressure connecting port connected to the high pressure chamber, a sensing port, an oil tank port, a long stroke port, and a short stroke port, a piston including small diameter portions, upper and lower large diameter portions, a sensing fluid groove between the upper and lower large diameter portions, and a return fluid groove formed on the lower the large diameter portion, a fluid circuit unit to control a supply direction of the fluid to the cylinder and to generate a fluid pressure to selectively change a stroke, and a chisel to break the bedrock when a lower portion of the piston descends to impact the chisel during a descending operation.

A two-step auto stroke hydraulic breaker includes a cylinder including a high-low pressure chamber, a high pressure chamber, and a pressure converting chamber including a pilot port, a high pressure connecting port connected to the high pressure chamber, a sensing port, an oil tank port, a long stroke port, and a short stroke port, a piston including small diameter portions, upper and lower large diameter portions, a sensing fluid groove between the upper and lower large diameter portions, and a return fluid groove formed on the lower the large diameter portion, a fluid circuit unit to control a supply direction of the fluid to the cylinder and to generate a fluid pressure to selectively change a stroke, and a chisel to break the bedrock when a lower portion of the piston descends to impact the chisel during a descending operation.

A non-impact fence post driver attachable to a front end loader or similar mobile machine for operation has a hydraulic driven sleeve assembly suspended from a U-joint so as to vertically self-align from the loader, and has a fence post holding shell assembly attached to the sleeve with retractable gate hinged locking assembly to hold the fence post securely near the bottom while driving the post.

A reciprocating hammer with a two-stage acceleration of a pile driving ram, including a first stage in which initial gravitational acceleration is assisted by a thruster and a second stage in which the initially accelerated ram is allowed to further accelerate under the force of gravity alone for the remainder of the pile driver stroke. The force assist in the initial acceleration stage acts as a force multiplier, such that the anvil delivers impact forces to the pile greater than the impact forces achievable by gravity alone for a given stroke length/ram weight combination.

A reciprocating hammer with a two-stage acceleration of a pile driving ram, including a first stage in which initial gravitational acceleration is assisted by a thruster and a second stage in which the initially accelerated ram is allowed to further accelerate under the force of gravity alone for the remainder of the pile driver stroke. The force assist in the initial acceleration stage acts as a force multiplier, such that the anvil delivers impact forces to the pile greater than the impact forces achievable by gravity alone for a given stroke length/ram weight combination.

A sheet pile retaining wall system employing corrugated sheet piles not requiring temporary shoring to be used when widening and/or stabilization of existing highway embankment. The wall system provides a front face wall having a plurality of resistance fins perpendicularly extending therefrom via three-way connectors. The fin sheet piles first include a brace fin sheet for reducing stresses in the front face wall, then a series of additional resistance fin sheets terminating at an elevation below the face wall for accommodating a pipe drainage/utility cradle. Between the slope of the existing embankment, a temporary excavation bench, an excavation backslope, and the higher front face wall is reinforced concrete backfill for pre-stressing the wall system when fluidand, when set, optionally engaging supplementary structural features within the set concrete backfill such as dowels/tie down anchors.

A sheet pile retaining wall system employing corrugated sheet piles not requiring temporary shoring to be used when widening and/or stabilization of existing highway embankment. The wall system provides a front face wall having a plurality of resistance fins perpendicularly extending therefrom via three-way connectors. The fin sheet piles first include a brace fin sheet for reducing stresses in the front face wall, then a series of additional resistance fin sheets terminating at an elevation below the face wall for accommodating a pipe drainage/utility cradle. Between the slope of the existing embankment, a temporary excavation bench, an excavation backslope, and the higher front face wall is reinforced concrete backfill for pre-stressing the wall system when fluidand, when set, optionally engaging supplementary structural features within the set concrete backfill such as dowels/tie down anchors.

Disclosed embodiments include post driving implements which attach to a power machine such as a loader in order to pick up posts of various sizes and materials and/or to drive the posts into the ground. In some exemplary disclosed embodiments, the post driving implement allows a post to be picked up when positioned inline with a direction of power machine travel and allows the post to rotate under the force of gravity to a second position in which the post is inline with a pounding mechanism for pounding the post into the ground. Catch mechanisms can be included to capture a portion of the implement to maintain the post in the second position until a release action is taken or a release command is given.

Disclosed embodiments include post driving implements which attach to a power machine such as a loader in order to pick up posts of various sizes and materials and/or to drive the posts into the ground. In some exemplary disclosed embodiments, the post driving implement allows a post to be picked up when positioned inline with a direction of power machine travel and allows the post to rotate under the force of gravity to a second position in which the post is inline with a pounding mechanism for pounding the post into the ground. Catch mechanisms can be included to capture a portion of the implement to maintain the post in the second position until a release action is taken or a release command is given.

A driving cylinder of a pile driving rig includes a solenoid valve for controlling an operation of the driving cylinder, which solenoid valve, is a slide valve, which is located at least partly at a piston-side head of the driving cylinder, and a stem of the slide valve is at least partly outside an inner cylinder liner in a direction of motion of a piston part. Further disclosed is a pile driving rig comprising the driving cylinder according to the invention.