Snubber for excavator bucket door
First Claim
1. A snubber for damping the closing of a door on an excavator bucket, the snubber comprising:
- (a) a housing mountable to an excavator bucket, the housing defining a cavity having opposed first and second end walls and an outer wall;
(b) a stationery dam member within the cavity, the dam member extending between the end walls;
(c) a pivotally movable wiper arm in the cavity, the wiper arm having a leading face, the wiper arm and the dam member dividing the cavity into sealed first and second volumes with the leading side of the wiper arm in the first volume;
(d) sealing means on the wiper arm, the sealing means sealing between the wiper arm and the first and second end walls and between the wiper arm and the outer wall, the sealing means between the wiper arm and the first end wall comprising;
(i) a first sealing member;
(ii) biasing means for biasing the first sealing member against the first end wall; and
,(iii) a fluid passage extending between the leading side of the wiper arm and a chamber between the sealing member and the wiper arm;
(e) a shaft extending from the housing, the shaft coupled to the wiper arm so that rotation of the shaft causes pivotal motion of the wiper arm;
(f) a flow restrictor having one end in fluid contact with the first volume and another end in fluid contact with the second volume; and
,(g) a fluid in the first and second sealed volumes;
wherein rotation of the shaft in a first direction increases pressure in the first sealed volume and causes the fluid to flow through the flow restrictor and rotation of the shaft in a second direction opposite to the first direction increases pressure in the second sealed volume and causes the fluid to flow through the one way valve.
1 Assignment
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Accused Products
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.
25 Citations
16 Claims
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1. A snubber for damping the closing of a door on an excavator bucket, the snubber comprising:
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(a) a housing mountable to an excavator bucket, the housing defining a cavity having opposed first and second end walls and an outer wall; (b) a stationery dam member within the cavity, the dam member extending between the end walls; (c) a pivotally movable wiper arm in the cavity, the wiper arm having a leading face, the wiper arm and the dam member dividing the cavity into sealed first and second volumes with the leading side of the wiper arm in the first volume; (d) sealing means on the wiper arm, the sealing means sealing between the wiper arm and the first and second end walls and between the wiper arm and the outer wall, the sealing means between the wiper arm and the first end wall comprising; (i) a first sealing member; (ii) biasing means for biasing the first sealing member against the first end wall; and
,(iii) a fluid passage extending between the leading side of the wiper arm and a chamber between the sealing member and the wiper arm; (e) a shaft extending from the housing, the shaft coupled to the wiper arm so that rotation of the shaft causes pivotal motion of the wiper arm; (f) a flow restrictor having one end in fluid contact with the first volume and another end in fluid contact with the second volume; and
,(g) a fluid in the first and second sealed volumes; wherein rotation of the shaft in a first direction increases pressure in the first sealed volume and causes the fluid to flow through the flow restrictor and rotation of the shaft in a second direction opposite to the first direction increases pressure in the second sealed volume and causes the fluid to flow through the one way valve. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A bucket assembly for an excavator, the bucket assembly comprising:
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(a) a U-shaped frame having front and rear openings; (b) a door pivotally mounted to the frame, the door having a closed position wherein the rear opening is blocked and an open position wherein the rear opening is substantially unobstructed; (c) a latch operatively associated with the door and the frame for maintaining the door in the closed position; (d) a snubber connected between the frame and the door, the snubber comprising; i) a housing enclosing a cylindrical cavity, the cavity having generally planar first and second end walls and an outer wall; ii) a stationery dam member within the cavity, the dam member extending between the end walls; iii) a pivotally movable wiper arm in the cavity, the wiper arm having a leading face, the wiper arm and the dam member dividing the cavity into sealed first and second volumes with the leading side of the wiper arm in the first volume; iv) sealing means on the wiper arm, the sealing means sealing between the wiper arm and the first and second end walls and between the wiper arm and the outer wall, the sealing means between the wiper arm and the first end wall comprising; 1) a first sealing member; 2) biasing means for biasing the first sealing member against the first end wall; and
,3) a fluid passage extending between the leading side of the wiper arm and a chamber between the sealing member and the wiper arm; v) a shaft extending from the housing, the shaft coupled to the wiper arm so that rotation of the shaft causes pivotal motion of the wiper arm; vi) a flow restrictor having one end in fluid contact with the first volume and another end in fluid contact with the second volume; and
,vii) a fluid in the first and second volumes; wherein the shaft moves the wiper arm toward the first volume while the door is closing and the shaft moves the wiper arm toward the second volume while the door is opening. - View Dependent Claims (15, 16)
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Specification