Abstract: The present invention relates to an unmanned self-propelled and self-steering device for removing manure present on a floor, including a manure slide and a drive for moving the device over the floor, wherein the manure slide is substantially U-shaped or V-shaped with two legs in order to define autonomously a manure-accommodating-space which opens in a forward direction and is closed in a rearward direction, and wherein the legs have a length in the order of magnitude of the width of the manure slide.

Abstract: The present invention relates to an unmanned self-propelled and self-steering device for removing manure present on a floor, including a manure slide and a drive for moving the device over the floor, wherein the manure slide is substantially U-shaped or V-shaped with two legs in order to define autonomously a manure-accommodating-space which opens in a forward direction and is closed in a rearward direction, and wherein the legs have a length in the order of magnitude of the width of the manure slide.

Abstract: A mining vehicle includes one or more crawlers, a first deck positioned above the crawlers, and a second deck positioned above the first deck. The first deck includes a first floor surface providing a walking surface, and one or more first deck maintenance components configured to allow a person to move among and access the first deck maintenance components. The second deck includes a second floor surface providing a walking surface, one or more second deck maintenance components, and one or more aisles configured to allow a person to move among and access the second deck maintenance components. The first and second decks are configured to provide maintenance access to the first and second deck maintenance components.

Abstract: A dipper assembly includes a body defining an outer surface and an opening, a door pivotably coupled to the body, and a latch mechanism releasably securing the door relative to the body. The door is pivotable between a closed position in which the door is positioned adjacent the opening and an open position in which the door is positioned away from the opening. The latch mechanism includes a latchkeeper and a latch member engaging the latchkeeper. The latch member is coupled to one of the body and the door and the latchkeeper is coupled to the other of the body and the door. The latchkeeper includes an end surface and a stop member coupled to the end surface. The stop member engages the one of the body and the door when the door is in the closed position. The stop member is extendable relative to the end surface.

Abstract: A rolled latch for excavator buckets that increases duration and facilitates maintenance work since it is changed instead of requiring weld fill, and includes three primary parts: a core, a top wear plate and a bottom wear plate. The parts are manufactured of rolled steel. The core remains between the top and bottom wear plates, and the top and bottom wear plates are welded to the core.

Abstract: A dipper assembly includes a dipper, a dipper door, a closure mechanism, a trip assembly, and a camshaft support assembly. The dipper door is pivotally mounted to the dipper for movement between an open position and a closed position in which the dipper door covers the dipper bottom. The closure mechanism is configured to retain the dipper door in the closed position. The trip assembly is configured to release the dipper door for movement to the open position, and includes a trip arm coupled to a camshaft and also coupled to a trip rope. The camshaft support assembly is configured to receive the camshaft, and includes a bearing block receiving a rotatable bearing member, and a sealing mechanism.

Abstract: A mining machine includes a boom, a handle coupled to the boom, a dipper coupled to the handle, and a dipper door pivotally coupled to the dipper. The mining shovel also includes a dipper door trip assembly including a trip motor coupled to the boom, a trip drum coupled to the handle, a linkage assembly coupled to the dipper door, a first actuation element extending directly from the trip motor to the trip drum, and a second actuation element extending directly from the trip drum to the linkage assembly.

Abstract: A dipper assembly includes a dipper, a dipper door, and a closure mechanism. The dipper door is coupled to the dipper, and has a closed position in which the dipper door covers the dipper bottom. The closure mechanism has a first position and a second position. In the first position the closure mechanism is configured to permit movement of the dipper door away from the dipper bottom. In the second position, the closure mechanism is configured to retain the dipper door in the closed position. The closure mechanism includes a link having a first leg and a second leg, one or more side link plates coupled to the link and to the dipper back, and a closure mechanism pin assembly configured to adjust the position of the link relative to the dipper door.

Abstract: An actuator system for a machine includes a linear hydraulic actuator connected to a dipper of the machine, and a hydraulic system fluidly connected to the actuator and configured to selectively direct fluid to the actuator. A component of the hydraulic system is mounted on the dipper. The system also includes an overcenter link coupled to a door of the dipper and biased to maintain the door in a closed position. A piston assembly of the actuator is configured to move the overcenter link in a first direction, via contact between the piston assembly and the overcenter link, thereby transitioning the door from the closed position to an open position.

Abstract: An actuator system for a machine includes a hydraulic actuator connected to a dipper of the machine, and a hydraulic system fluidly connected to the actuator and configured to selectively direct fluid to the actuator. A component of the hydraulic system is mounted on the dipper. The system also includes an overcenter link coupled to a door of the dipper and biased to maintain the door in a closed position. The actuator is operable to move the overcenter link in a first direction, thereby transitioning the door from the closed position to an open position.

Abstract: A power shovel dipper door includes a hollow dipper body defining a first end and a second end opposite the first end, a plurality of dipper teeth coupled to the first end, a dipper door pivotally mounted at the second end, and a latch system for releasably securing the dipper door in a closed position. The latch system includes a latch bar and a latch keeper. At least one of the latch bar and latch keeper is movable between a first position and a second position. The latch keeper is engaged by the latch bar when at least one of the latch bar and latch keeper is in the first position. The latch system further includes removable inserts positioned proximate an interface where the latch bar and latch keeper are capable of engaging each other. One or more of the removable inserts includes a tool steel.

Abstract: A dipper assembly for a mining shovel includes a dipper body, a dipper door pivotably coupled to the dipper body, an arm, a housing coupled to one of the body and the door, and a piston. The arm includes a first end pivotably coupled to the body and a second end pivotably coupled to the door. The movement of the door relative to the body drives the arm to pivot relative to the body. The housing includes an inlet in fluid communication with a fluid source, an outlet, and a cylinder partially defining a pump chamber in fluid communication with the inlet and the outlet. The piston is movable within the cylinder and biased in a first direction. The pivoting movement of the arm causes the piston to move in a second direction opposite the first direction. The movement of the piston changes a volume of the pump chamber.

Abstract: A hydraulic system for a power shovel may have a tank, a pump configured to draw fluid from the tank and pressurize the fluid, a crowd cylinder extendable and retractable to adjust a length of a dipper handle, and a valve in fluid communication with the tank, the pump, and the crowd cylinder. The valve may be movable to fill chambers of the crowd cylinder with fluid pressurized by the pump and to drain the chambers of the crowd cylinder to cause extension and retraction of the crowd cylinder. The hydraulic system may also have a dipper actuator located at an end of the crowd cylinder, and a passage extending through the crowd cylinder to communicate with the dipper actuator.

Abstract: A hydraulic system for a power shovel may have a cylinder operatively connectable to a dipper door of the power shovel, a reservoir located at and fluidly connected to the cylinder, and an accumulator located at and fluidly connected to the cylinder in parallel with the reservoir. The hydraulic system may further have a control valve disposed between the cylinder, the reservoir, and the accumulator. The control valve may be movable to selectively direct fluid from the cylinder into the accumulator and fluid from the reservoir into the cylinder.

Abstract: A dipper including a dipper door and an impact actuated jaw defining a lip and a chin The jaw is rotatably mounted on the dipper door for rotation between a door-opened position and a door-closed position and positioned so that when the jaw is in the door-opened position, the jaw chin can be impacted by the dipper body when the door pivots to the door-closed position. The dipper also includes a hold open mechanism for releasably holding the door latch in the latch open position when the latch is in the open position, and a locking mechanism for releasably locking the latch when the latch is in the door-closed position. The locking mechanism includes one bar pivotally attached to the door, and another bar pivotally connected to and extending between each of the one bar and the latch.

Abstract: An actuator system for a machine includes a hydraulic actuator connected to a dipper of the machine, and a hydraulic system fluidly connected to the actuator and configured to selectively direct fluid to the actuator. A component of the hydraulic system is mounted on the dipper. The system also includes an overcenter link coupled to a door of the dipper and biased to maintain the door in a closed position. The actuator is operable to move the overcenter link in a first direction, thereby transitioning the door from the closed position to an open position.

Abstract: A bucket for use with a cable shovel includes a shell and a door collectively defining a cavity for gathering material to be excavated. The door is pivotally secured about a pivot axis on the shell so that the door can pivot between a closed position for gathering the material and an open position for dumping the material. The pivot axis is positioned forward of an exterior surface of a back wall of the shell to create a shallower and less forceful door swing during dumping. The door has a front portion that is bent towards a digging edge on the shell so that the door has greater strength, improves bucket loading, and moves a portion of the shell away from the highest wear area.

Abstract: A dipper assembly for a mining shovel, includes a dipper having a dipper back and an open dipper bottom, and a dipper door pivotally mounted to the dipper, configured to pivot between an open position and a closed position with a swing speed, and to cover the open dipper bottom. The dipper assembly also includes one or more hydraulic door snubbers. The hydraulic door snubbers include a base having one or more connecting plates, one or more mounting plates coupled to the base and configured to receive a link extending from the dipper door, one or more friction plates, and a hydraulic cylinder configured to clamp the mounting plates, the connecting plates, the friction plates and the link together.

Abstract: A retarding mechanism for continuously retarding the swinging movements of a dipper door comprises a hydraulic braking assembly mounted to the dipper bucket and operatively connected to the dipper door via at least one braking arm pivotally mounted within the braking assembly and at least one linking member pivotally mounted to the dipper door. The retarding mechanism continuously retards the opening and closing movements of the dipper door by controllably braking or slowing the at least one braking arm using the compressive action of at least one hydraulic piston mounted to the braking assembly.

Abstract: A dipper including a dipper door and an impact actuated jaw defining a lip and a chin The jaw is rotatably mounted on the dipper door for rotation between a door-opened position and a door-closed position and positioned so that when the jaw is in the door-opened position, the jaw chin can be impacted by the dipper body when the door pivots to the door-closed position. The dipper also includes a hold open mechanism for releasably holding the door latch in the latch open position when the latch is in the open position, and a locking mechanism for releasably locking the latch when the latch is in the door-closed position. The locking mechanism includes one bar pivotally attached to the door, and another bar pivotally connected to and extending between each of the one bar and the latch.

Abstract: A spring assembly for a latch mechanism includes a spring, a first support, and a second support. The spring includes a first end, a second end, and a plurality of coils extending therebetween. The coils define an internal helical surface. The first support is configured to be coupled to a first pivoting member. The first support includes a grooved surface for threadingly engaging at least a portion of the internal helical surface of the spring proximate the first end. The second support is configured to be coupled to a second pivoting member. The second support includes a grooved surface for threadingly engaging at least a portion of the internal helical surface of the spring proximate the second end.

Abstract: A dipper assembly includes a body defining an outer surface and an opening, a door pivotably coupled to the body, and a latch mechanism releasably securing the door relative to the body. The door is pivotable between a closed position in which the door is positioned adjacent the opening and an open position in which the door is positioned away from the opening. The latch mechanism includes a latchkeeper and a latch member engaging the latchkeeper. The latch member is coupled to one of the body and the door and the latchkeeper is coupled to the other of the body and the door. The latchkeeper includes an end surface and a stop member coupled to the end surface. The stop member engages the one of the body and the door when the door is in the closed position. The stop member is extendable relative to the end surface.

Abstract: A dipper assembly for a mining shovel includes a dipper body, a dipper door pivotably coupled to the dipper body, an arm, a housing coupled to one of the body and the door, and a piston. The arm includes a first end pivotably coupled to the body and a second end pivotably coupled to the door. The movement of the door relative to the body drives the arm to pivot relative to the body. The housing includes an inlet in fluid communication with a fluid source, an outlet, and a cylinder partially defining a pump chamber in fluid communication with the inlet and the outlet. The piston is movable within the cylinder and biased in a first direction. The pivoting movement of the arm causes the piston to move in a second direction opposite the first direction. The movement of the piston changes a volume of the pump chamber.

Abstract: A drilling bucket adapted to combine with a prime mover vehicle such as an excavator. The drilling bucket includes a floor pivotally combined with the bucket. The floor has an open position wherein collected spoils are emptied from the bucket and a closed position for retaining spoils in the bucket during operation. A release assembly is adapted to securely hold the floor in its closed position until it is actuated to release it to its open position. Some embodiments of the drilling bucket comprise two separate internal cavities. The first cavity is adapted to receive the spoils as the bucket is rotated beneath the ground by the prime mover vehicle. The second cavity is adapted to house portions of the release assembly. The second cavity may serve as a vent which allows air to pass the bucket as the bucket is being raised or lowered in a hole.

Abstract: A rolled latch for excavator buckets that increases duration and facilitates maintenance work since it is changed instead of requiring weld fill, and includes three primary parts: a nucleus, a top lid and a bottom lid. The parts are manufactured of rolled steel. The nucleus remains between the top and bottom lids, and the top and bottom lids are welded to the nucleus.

Abstract: A dipper including a dipper door and an impact actuated jaw having a “C” shape defining a lip and a chin. The jaw is rotatably mounted on the dipper door for rotation between a door-opened position and a door-closed position and positioned so that when the jaw is in the door-opened position, the jaw chin can be impacted by the dipper body when the door pivots to the door-closed position. The dipper also includes a hold open mechanism for releasably holding the door latch in the latch open position when the latch is in the open position, and a locking mechanism for releasably locking the latch when the latch is in the door-closed position. The locking mechanism includes one bar pivotally attached to the door, and another bar pivotally connected to and extending between each of the one bar and the latch.

Abstract: A dipper assembly includes a dipper, a dipper door, a closure mechanism, and one or more block assemblies. The dipper door is pivotally mounted to the dipper, and has a closed position in which the dipper door covers the dipper bottom. The closure mechanism has a locked position and an unlocked position, and is coupled to the dipper back and the dipper door. In the locked position, the closure mechanism holds the dipper door in the closed position. In the unlocked position, the closure mechanism allows the dipper door to swing away from the closed position. The block assemblies are coupled to the dipper back and limit a rotation of the side link plate to a pre-defined angle that corresponds to the closed position.

Abstract: A dipper assembly includes a dipper, a dipper door, a closure mechanism, a trip assembly, and a camshaft support assembly. The dipper door is pivotally mounted to the dipper for movement between an open position and a closed position in which the dipper door covers the dipper bottom. The closure mechanism is configured to retain the dipper door in the closed position. The trip assembly is configured to release the dipper door for movement to the open position, and includes a trip arm coupled to a camshaft and also coupled to a trip rope. The camshaft support assembly is configured to receive the camshaft, and includes a bearing block receiving a rotatable bearing member, and a sealing mechanism.

Abstract: A dipper assembly includes a dipper, a dipper door, and a closure mechanism. The dipper door is coupled to the dipper, and has a closed position in which the dipper door covers the dipper bottom. The closure mechanism has a first position and a second position. In the first position the closure mechanism is configured to permit movement of the dipper door away from the dipper bottom. In the second position, the closure mechanism is configured to retain the dipper door in the closed position. The closure mechanism includes a link having a first leg and a second leg, one or more side link plates coupled to the link and to the dipper back, and a closure mechanism pin assembly configured to adjust the position of the link relative to the dipper door.

Abstract: A closure member is pivotally connected with respect to a hydraulically operated bucket. A link member is pivotally connected to a hydraulically operated arm segment. The link member is also pivotally connected to the closure member. The closure member and the hydraulically operated bucket are connected for simultaneous pivotal movement in opposite directions with respect to each other.

Abstract: Apparatus and method for material distribution, including a draw-bar to which is fixedly connected a bucket body. Wheels are attached to the drawbar on opposite sides of the bucket body between an open side and a gate thereof. A lower edge of the open side of the bucket body, which can receive material, is in the form of a cutting blade or teeth. The gate, which is disposed opposite from the open side, can be opened and closed. At least part of a top side of the bucket body forms a platform for an operator. At least one engine is provided and is drivingly connected to the wheels. A handlebar is connected to the bucket body, forward of the platform, for pivoting the bucket body about the wheels so that the cutting blade or teeth can be brought into or out of contact with a surface.

Abstract: A snubber for a mining shovel including a dipper body and a dipper door rotatably coupled to the dipper body. The snubber includes a housing having an internal wall defining a fluid-filled chamber, a shaft rotatably coupled to the housing and including a portion positioned within the chamber, a paddle positioned within the chamber, a dam positioned within the chamber, a first valve, and a second valve. Rotation of the dipper door relative to the dipper body causes rotation of the shaft relative to the housing. The paddle is coupled to the shaft such that the paddle rotates with the shaft. The dam and paddle substantially partition the internal chamber into a first portion and a second portion. The first valve controls fluid flow from the first chamber to the second chamber, and the second valve controls fluid flow from the second chamber to the first chamber.

Abstract: A dipper including a dipper door and an impact actuated jaw having a “C” shape defining a lip and a chin. The jaw is rotatably mounted on the dipper door for rotation between a door-opened position and a door-closed position and positioned so that when the jaw is in the door-opened position, the jaw chin can be impacted by the dipper body when the door pivots to the door-closed position. The dipper also includes a hold open mechanism for releasably holding the door latch in the latch open position when the latch is in the open position, and a locking mechanism for releasably locking the latch when the latch is in the door-closed position. The locking mechanism includes one bar pivotally attached to the door, and another bar pivotally connected to and extending between each of the one bar and the latch.

Abstract: A retarding mechanism for continuously retarding the swinging movements of a dipper door is disclosed. The retarding mechanism comprises a hydraulic braking assembly mounted to the dipper bucket and operatively connected to the dipper door via at least one braking arm pivotally mounted within the braking assembly and at least one linking member pivotally mounted to the dipper door. The retarding mechanism continuously retards the opening and closing movements of the dipper door by controllably braking or slowing the at least one braking arm using the compressive action of at least one hydraulic piston mounted to the braking assembly.

Abstract: A dipper including a dipper door and an impact actuated jaw having a “C” shape defining a lip and a chin The jaw is rotatably mounted on the dipper door for rotation between a door-opened position and a door-closed position and positioned so that when the jaw is in the door-opened position, the jaw chin can be impacted by the dipper body when the door pivots to the door-closed position. The dipper also includes a hold open mechanism for releasably holding the door latch in the latch open position when the latch is in the open position, and a locking mechanism for releasably locking the latch when the latch is in the door-closed position. The locking mechanism includes one bar pivotally attached to the door, and another bar pivotally connected to and extending between each of the one bar and the latch.

Abstract: A wheeled load transfer device has a load carrying member, a handle assembly and a pair of wheels optionally connected to a distal end of the handles and preferably offset below the plane of the handles. The load carrying member includes opposing side portions, a bottom portion. The load carrying member is rotatable between a first loading position which is preferably parallel to the ground and a second load transporting position which is inclined to the ground to better retain the load. The load carrying member can be rotated to different positions to scoop, transport and dump the load.

Abstract: A dipper including a dipper door and an impact actuated jaw having a “C” shape defining a lip and a chin. The jaw is rotatably mounted on the dipper door for rotation between a door-opened position and a door-closed position and positioned so that when the jaw is in the door-opened position, the jaw chin can be impacted by the dipper body when the door pivots to the door-closed position. The dipper also includes a hold open mechanism for releasably holding the door latch in the latch open position when the latch is in the open position, and a locking mechanism for releasably locking the latch when the latch is in the door-closed position. The locking mechanism includes one bar pivotally attached to the door, and another bar pivotally connected to and extending between each of the one bar and the latch.

Abstract: A quick-release multipurpose implement for pivotal attachment to a loader bucket of the type having a load receiving volume defined in part by opposing upright spaced apart sides. The implement comprises a pivot frame sized to fit over the receiving volume formed by a loader bucket. The pivot frame includes two opposing pivot arm supports that extend from the pivot frame for pivotally supporting the pivot frame in a plurality of positions relative to the loader bucket. A receiving base is provided and designed to be mounted and fixed to each side of the loader bucket for pivotally receiving a pivot arm support. At least one axially adjustable means is employed to extend from the receiving base to the pivot frame for pivotally moving the frame from a first open position so that the bucket volume can be loaded, to a second closed position to cover the receiving volume of the bucket.

Abstract: An extendable frame work vehicle offering enhanced versatility, safety and effectiveness. The vehicle includes an adjustable frame with front and rear portions that extend or retract with respect to each other. The front portion is supported by a first pair of wheels and said rear portion is supported by a second pair of wheels. Each wheel is independently driven and steered. The vehicle also includes an engine mounted on the rear portion of the frame. Incorporated into the vehicle is an electro-hydraulic assembly which enables extension and retraction of the adjustable frame. The assembly includes a sensor-responsive microprocessor controller, at least one hydraulic pump, at least one hydraulic drive motor, and at least one valve network.

Abstract: An excavation bucket assembly (10) is mounted to a tractor. A soil gathering trenching blade (48) is supported by an upwardly extending rear wall (18) and is movable down through a soil receiving opening (32) to scoop soil from beneath the ground wall (16) of the bucket, with the opening (32) being placed rearwardly of the front edge (30) of the ground wall, providing adequate space in the soil collection chamber (28) for receiving the excavated soil.

Abstract: A pusher/bucket has back plate with wings pivotably mounted at either end, and a drop blade pivotably mounted thereto. The drop blade can be secured in a raised position where it is superimposed over the back plate; when in the raised position, the wings can be positioned relative to the back plate to provide a wing plow. The wings can be folded parallel to the back plate, with the raised drop blade residing therebetween. When the wings are normal to the back plate, the drop blade can be secured in a lowered, horizontal position; in this position, the drop blade acts as the bottom of a loading bucket, the sides being formed by the wings and the back plate. A float mechanism allows the pusher/bucket to push material across uneven terrain, and is preferably disabled when the pusher/bucket is configured as a bucket for loading and dumping material.

Abstract: A scraping device, a system and a method for collecting a material are provided. The scraping device may have a bowl having a first end and a second end. A lip may be positioned at the first end and may cover an opening at the first end. In an embodiment, direct mounted cylinders may be attached to the lip and may move the lip to completely cover or uncover the opening. The scraping device may have a tongue mounted to the bowl having a triangular-shaped plate mechanism that may be used to raise and to lower a cutting edge attached to the bowl. Cylinders connected to the mechanism may be retracted or extended to raise or to lower the scraping device. A load within the scraping device may be lifted by force exerted from a barrel end of a cylinder, thus utilizing a maximum potential of the cylinder.

Abstract: A dipper assembly includes a dipper, a dipper door, ands a closure mechanism. The dipper door is pivotally linked relative to the dipper, and has a closed position in which the dipper door closes the open bottom. The closure mechanism has a lock position and an unlock position, and is fixed relative to the dipper and linked to the dipper door. In the lock position, the closure mechanism holds the dipper door in the closed position. In the unlock position, the closure mechanism allows the dipper door to swing away from the closed position.

Abstract: A scraping device, a system and a method for collecting a material are provided. The scraping device may have a bowl having a first end and a second end. A lip may be positioned at the first end and may cover an opening at the first end. In an embodiment, direct mounted cylinders may be attached to the lip and may move the lip to completely cover or uncover the opening. The scraping device may have a tongue mounted to the bowl having a triangular-shaped plate mechanism that may be used to raise and to lower a cutting edge attached to the bowl. Cylinders connected to the mechanism may be retracted or extended to raise or to lower the scraping device. A load within the scraping device may be lifted by force exerted from a barrel end of a cylinder, thus utilizing a maximum potential of the cylinder.

Abstract: A dipper assembly includes a dipper having an open bottom and forward end, and a door pivotally linked to the dipper. The dipper bottom is defined by dipper wall bottom edges. The door has a bottom wall and side walls which extend above the bottom wall to define a volume between the side walls, wherein top edges of the side walls abut bottom edges of the dipper wall bottom edges to close the dipper bottom.

Abstract: A dipper door pivotally mounted to a dipper is controlled as it pivots between open and closed positions. In one embodiment, the door is controlled by a brake pivotally linking the door to the dipper. In another embodiment, the door is pivotally mounted to the dipper by a pin, and the door is controlled by a linkage actuated by a linear actuator. The pivot point of the door is positioned above the dipper bottom to decrease the dump height of the dipper.

Abstract: A dipper assembly includes a dipper having an open bottom and forward end, and a door pivotally linked to the dipper. The dipper bottom is defined by dipper wall bottom edges. The door has a bottom wall and side walls which extend above the bottom wall to define a volume between the side walls, wherein top edges of the side walls abut bottom edges of the dipper wall bottom edges to close the dipper bottom.

Abstract: An implement for use with a bucket mounted to a dipper boom of an earth working machine wherein the implement includes bars slidable mounting within guide elements mounted to the dipper boom such that the bars may be moved by gravity from a first position spaced from the bucket to a second position in generally opposing relationship with respect to an opening in the bucket so as to facilitate the retention of materials within the bucket.

Abstract: Power shovels include a dipper door which must be held shut to retain a load of material within a dipper and which must be allowed to open to discharge the load of material from the dipper. Such dipper doors are extremely heavy and, as a result, the opening and closing of the dipper doors must be dampened in order to prevent the dipper doors from banging against other components of the power shovels. There is provided a hydraulic assembly which is mounted to a dipper body and a dipper door of a dipper of a power shovel. The hydraulic assembly includes a restricted flow conduit to prevent unrestricted flow of hydraulic fluid between fluid chambers of the hydraulic assembly. Accordingly, as the dipper door opens or closes, as the hydraulic fluid moves from one chamber of the hydraulic assembly to the other, the restricted movement of the fluid causes the dipper door to open or close in a controlled manner thereby dampening the effect of movement of the dipper door.

Abstract: A Snubber is used to damp the swing of the door on an excavator bucket to prevent the door form being damaged by repeatedly slamming shut. The snubber has housing which mounts to an excavator bucket and a shaft pivotally mounted in the housing and connected to an excavator door. The shaft turns when the excavator door opens. The housing has a cylindrical cavity around the shaft. The cavity is divided into two volumes by a dam and a wiper arm on the shaft. The wiper arm forces hydraulic fluid to flow through an orifice between the volumes as the shaft turns. The wiper arm has end seals which seal against end walls of the cavity. The end seals are forced outwardly by hydraulic pressure when the door is closing. A one-way valve allows hydraulic fluid to bypass the orifice while the door is opening. The snubber requires less maintenance than previous friction snubbers.