Patent ID: 9045883
Filing Date: 2015-06-02
Classification: E02F,F16F

Abstract:
1. A snubber for a mining shovel, the mining shovel including a dipper having a dipper body and a dipper door rotatably coupled to the dipper body, the snubber comprising: a housing including an internal wall defining a fluid-filled chamber; a shaft rotatably coupled to the housing and including a portion positioned within the chamber, wherein rotation of the dipper door relative to the dipper body causes rotation of the shaft relative to the housing; a paddle positioned within the chamber and coupled to the shaft such that the paddle rotates with the shaft, the paddle including a first side, a second side, and a paddle end extending between the first side and the second side, the paddle end including a channel; a shuttle valve including a first port positioned on the first side of the paddle and a second port positioned on the second side of the paddle, and a shuttle member movable between a first position in which the first port is in fluid communication with the channel and a second position in which the second port is in fluid communication with the channel; a paddle vane positioned adjacent the paddle end and biased toward the internal wall; a piston including a first end positioned in the channel and a second end positioned adjacent the paddle vane; a dam positioned within the chamber such that the dam and the paddle substantially partition the internal chamber into a first portion adjacent the first side of the paddle and a second portion adjacent the second side of the paddle; a first valve for controlling fluid flow from the first portion to the second portion; and a second valve for controlling fluid flow from the second portion to the first portion, wherein when pressure in the first portion is greater than pressure in the second portion, the shuttle member moves to the first position such that fluid in the first portion is in communication with the channel and applies pressure against the first end of the piston to bias the paddle vane toward the internal wall.