A quick hitch coupler for coupling an attachment to a dipper arm of an excavator, the quick hitch coupler comprising: (a) a body member adapted for coupling to the dipper arm, (b) a fixed engaging jaw mounted on the body member for engaging a first one of a pair of coupling pins mounted on the attachment, (c) a movable engaging jaw mounted on the body member for engaging a second one of the pair of coupling pins of the attachment, the movable engaging jaw being movable between an engaged state with the movable engaging jaw engaging the second coupling pin while the fixed engaging jaw engages the first coupling pin for coupling the attachment to the coupler, and a disengaged state for disengaging the second coupling pin, (d) a latch co-operable with the fixed engaging jaw for retaining the first coupling pin of the attachment engaged in the fixed engaging jaw the latch being alternately operable in a latched state co-operating with the fixed engaging jaw for retaining the first coupling pin in the fixed engaging jaw, and an unlatched state for releasing the first coupling pin from the fixed engaging jaw, (e) an urging means for urging the latch into the latched state, (f) a release block being movable on (and relative to) a guide, the release block being movable on the guide between a non-active position in which the latch remains in the latched state and an active position where the release block abuts against the latch to move the latch from the latched state to the unlatched state against the urging action of the urging means, (g) a drive means generating an amount of displacement: (i) for moving the movable engaging jaw from the engaged state to the disengaged state, and (ii) for moving the release block on the guide from the non-active position to the active position.
The drive means generates an amount of displacement for moving the movable engaging jaw but the release block is not moved and a second stage where the drive means generates an amount of displacement for moving the movable engaging jaw above a threshold amount where the release block is moved.

A quick-change coupler device for coupling and uncoupling an implement attachment to a construction vehicle comprises a support member; first receiving members on one side of the support member for receiving a first coupling member; second receiving members disposed on the other side for receiving a second coupling member, the second receiving members having a locking member moveable between a release position for coupling or uncoupling the implement attachment and a coupling position for retaining the implement attachment on the coupler device; and a mechanical signaling mechanism for monitoring the locking status. The mechanical signaling mechanism comprises an assembly for signaling failure of the second coupling member to engage in the second receiving members. The assembly comprises a coupling gear for moving a signaling member into a locking position when the locking member moves into the coupling position, and into an unlocking position when the at least one locking member moves beyond the coupling position.

A tool coupler for coupling a tool to an end of a machine link. The tool coupler having a coupler frame, a hook configured to receive a first pin of the tool and configured to attach to the end of the machine link such that the tool coupler, a wedge slidingly received within the coupler frame, and an actuator connected to the wedge to move the wedge away from the hook to bias a second pin of the tool against the coupler frame. The tool coupler mounts the tool to the machine link such that the tool and the tool coupler pivots about the same axis.

An adapter for a quick-change system for changing attachments on a construction machine contains coupling elements arranged at a stipulated spacing from each other between two side walls for connection of the adapter to a quick changer. In order to provide improved protection from damage, the rear ends of the two side walls project rearwardly with respect to a back cover arranged between the side walls.

A quick coupler circuit includes a cylinder to attach and/or detach an attachment to and/or from a construction machine by expansion and/or contraction, a flow pump to supply fluid to the cylinder, a valve through which fluid for operating the cylinder passes, a spool valve which includes a spool, to move along an axial direction, and to form a pressure at a node of the flow pump according to movement of the spool, an electronic proportional pressure reducing valve to control the spool valve, a switch to perform an ON/OFF operation, and a controller to output a control current to the electronic proportional pressure reducing valve in response to the operation of the switch. The controller is maintains control current which it outputs during the switch's ON operation for a predetermined period of time after the switch's OFF operation.

A working machine includes a ground engaging structure, and an undercarriage supported on the ground engaging structure. The undercarriage has a drive arrangement for moving the ground engaging structure to propel the working machine, the drive arrangement comprising a prime mover and a transmission comprising a hydraulic pump arrangement configured to be driven by the prime mover. A superstructure rotatably mounted to the undercarriage and a working arm is connected to the superstructure. A first implement mount connected the undercarriage for operably mounting a working implement to the undercarriage. The undercarriage has a first actuator for raising and lowering a working implement when mounted to the first implement mount and comprises a hydraulic connector for supplying hydraulic fluid to the first actuator to actuate the first actuator, and a first auxiliary hydraulic connector is provided that is configured for supplying hydraulic fluid to an implement connected thereto.

Hydraulic system (120) for a vehicle comprising a vehicle hydraulic circuit (122) among others for the hydraulic supply of connecting means of an automatic coupling means, wherein the connecting means is designed to connect a coupling means (31) of the vehicle with a correspondingly designed coupling means (32) of an add-on unit and an operating hydraulic circuit (121) for supplying at least one Power-Beyond coupling, wherein the vehicle hydraulic circuit and the operating hydraulic circuit are designed independent of one another and each having a hydraulic pump.

A quick-change system for changing attachments on a construction machine with a quick coupler arranged to be pivotable about a pivot axis orthogonal to the axis of rotation by means of a hydraulic slewing drive and rotatable about an axis of rotation on a connection part by means of a hydraulic rotary drive contains mounts and at least one locking element which can be actuated by means of a hydraulic drive to hold an attachment coupled to the quick coupler. The quick-change system includes a hydraulic control device, which contains a first control circuit to drive rotary drive and slewing drive, at least one additional control circuit to supply the attachment coupled to the quick coupler and a shuttle valve arrangement to expose the hydraulic drive to the higher pressures acting in the first or the at least one additional control circuit to activate the at least one locking element.

A working machine includes a rear machine body on which an operator's seat is mounted, a front machine body to which a working tool is attached, a center shaft having a first axis extending in a fore-and-aft direction, a first supporting part supporting the center shaft rotatably relative to the rear machine body around the first axis, a coupling shaft having a second axis extending in a vertical direction and connected to the front machine body, and a second supporting part supporting the center shaft rotatably relative to the coupling shaft relative to the second axis. The first supporting part includes a first spherical plain bearing, and the first spherical plain bearing includes a first inner wheel including a convex curved sliding surface and provided on an outer circumferential surface of the center shaft, and a first outer wheel including a concave curved sliding surface and provided on the rear machine body.

A working machine includes a machine body, a traveling device travelably supporting the machine body, a hydraulic driving device to hydraulically drive the traveling device, a floor frame supported on the machine body via a mounting member, a pedal operable to brake the traveling device, the inching valve to change a flow rate of hydraulic fluid supplied to the hydraulic driving device according to operation of the pedal, and a cable operably connecting the pedal to the inching valve. The pedal and the inching valve are attached to the floor frame.