An inner subassembly for assembling a valve assembly includes a spool defining a central bore that extends axially through the spool forming a spool annular wall, and including a spool cone tip that is disposed at the first axial end, as well as a hydraulic activation ridge extending radially outwardly from the spool annular wall, and that is disposed axially between the second axial end and the first axial end. The spool may further define a first bypass bore. A stem defines a first flow bore that aligns with the first bypass bore.

An impact hammer for breaking a working surface, the hammer including a drive mechanism and a housing with an inner containment surface and a reciprocating hammer weight. A reciprocation cycle of the hammer weight includes an upstroke and a down-stroke, the hammer weight respectively moving upwards and downwards. On the down-stroke the hammer weight impacts a striker pin with a driven end and a working surface impact end. A vacuum chamber in the housing is formed by the containment surface, upper vacuum sealing coupled to the hammer weight and lower vacuum sealing. The hammer weight is driven toward the striker pin by the pressure differential between atmosphere and the vacuum chamber formed on the upstroke. A down-stroke vent permits fluid egress from the vacuum chamber on the down-stroke.

Systems and methods can include stretching a stud of a hammer assembly by tightening, according to a preset amount, a plurality of fasteners, which can extend from a first end surface and/or a second end surface of a first nut threadedly coupled to the stud, against an upper surface of a body of the hammer assembly. The fasteners and the first nut can provide a clamping load for the stud upon completion of the tightening. The systems and methods can also include, after the stretching, tightening a second nut, which can be threadedly connected to the stud, toward a seat formed in the body of the hammer assembly; and further tightening the second nut, against the seat. The systems and methods can further include transferring the clamping load from the fasteners and first nut to the second nut.

The present disclosure relates to a vibro-hammer 1 connected to heavy construction equipment, and more particularly, a vibro-hammer 1 having a side grip in which vibrations are prevented from being transmitted to a connected heavy equipment machine to avoid a problem such as a change in a perforation position, the vibro-hammer 1 is firmly connected to a perforated pile to transmit vibrations generated in a gear box to the perforated pile through the side grip and improve workability, arms are gear-coupled to each other to prevent the arms and the side grip from being released from each other due to frequent vibrations, a pair of arms and the side grip can come into close contact with the perforated pile or separated from the performed pile by a single cylinder, the side grip can be easily replaced according a shape of the perforated pile, and applicability and workability is improved.

Problem to be solved: To provide a hydraulic circuit for the construction machine which enables to use the relief valve of low capacity in the work tool circuit. Solution: The hydraulic circuit 2 for a construction machine has: a hydraulic pump 4 of variable capacity, a work tool 6 operated by hydraulic oil delivered by the hydraulic pump 4, a work tool operating device 10 to output a signal for operating the work tool 6, a control valve 14 allowing the hydraulic pump 4 to supply the hydraulic oil to the work tool 6 based on the signal output from the work tool operating device 10, a tool's relief valve 44 to release the hydraulic oil flowing between the control valve 14 and the work tool 6, a pressure sensor 46 to detect a pressure of hydraulic oil flowing into the work tool 6, and a controller 48 to reduce a delivery rate from the hydraulic pump 4 when the pressure detected by the pressure sensor 46 exceeds a predetermined value.

A tool for breaking rocks comprising a tool head supported by a guide means to be linearly displaceable with respect to the guide between a retracted position and an extended position, a distal end of said tool head extending from said guide to engage a surface to be broken when the tool head is in its extended position; a drive adapted to drive said tool head towards its retracted position in a first operation and to drive the tool head towards its extended position in a second operation, said drive including a drive part mounted on said guide and a driven part mounted on the tool head and engaged by said drive part to be linearly displaceable with respect to the guide upon operation of the drive part of the drive; and a controller adapted to control operation of the drive .

Systems and methods for monitoring an attachment, such as a breaker head, for a mining machine. The system includes a breaker head, a wireless identification tag, a sensor, and an electronic processor. The wireless identification tag is coupled to the breaker head and includes a tag memory storing an identifier of the breaker head and an antenna. The sensor is configured to generate measurement data associated with the breaker head. The electronic processor is configured to receive measurement data from the sensor, generate a notification based on the measurement data, and transmit the notification to the wireless identification tag. Additionally, the wireless identification tag is configured to store the notification. The notification can then be later retrieved from the wireless identification tag by various devices, such as a further mining machine or a reader device of maintenance personnel.

Provided is a manipulation apparatus for a rockbreaker, the apparatus comprising a manipulation tool defining at least one substantially flat surface, a mounting configured to swivelably mount the manipulation tool on the rockbreaker such that an angle formed between an axis along the flat surface and an impact axis of the rockbreaker is infinitely adjustable. Apparatus further includes an actuator arrangement configured to swivel the tool so that the flat surface is selectively and infinitely adjustable relative to the impact axis to facilitate manipulation of material by the tool.

A control system and method of controlling a utility vehicle. The system may include a controller, an energy mode input associated with a user input request to select one of at least two power modes, an implement control input associated with a user input request to select a movement of an implement, a drive control input associated with a user input request to select a movement of a drive system to propel the utility vehicle, and an attachment type input to further refine the allowed operating power states. The controller is adapted to determine a change between the plurality of operating power states in response to user input requests to automatically optimize machine performance and efficiency. Each of the plurality of operating power states includes a maximum electric current output and a maximum speed output of the electric motor.

A rock claw for attaching to a corner of a demolition hammer, the rock claw including a first wall having a first inner side surface, a second wall having a second inner side surface joined to the first inner side surface along a first intersection, and a third wall having a third inner side surface. The third inner side surface is joined to the first inner side surface along a second intersection and the third inner side surface is joined to the second inner side surface along a third intersection.