Patent ID: 9297141
Filing Date: 2016-03-29
CPC Classification: E02F,F15B,Y10T

Claim Text:
1. A coupler for an excavator, the coupler comprising a body for receiving an excavator attachment; a first latch member movable into and out of a latching state in which it is capable of retaining the attachment on said body; said first latch member operatively connected with said body and being movable into and out of said latching state by means of a hydraulic or pneumatic actuator, wherein a gravity operated valve is associated with the actuator, said valve having a first state, wherein fluid can flow through the valve as the latch member is moved out of its latching state, and a second state, wherein fluid is prevented from flowing through the valve thus preventing operation of the actuator to move the latch member out of its latching state, said valve being adapted to adopt said first state when the coupler is in a non-working orientation and said second state when the coupler is in a working orientation, wherein said valve comprises a flow passage in a hydraulic circuit of the actuator having a fluid inlet and a fluid outlet, a portion of said flow passage defining a valve seat located between said fluid inlet and said fluid outlet, a valve stop member in the form of a ball being provided within the flow passage, said valve stop member being out of said valve seat under the action of gravity when the valve is in its first state due to rotation of the coupler to its non-working orientation, allowing fluid to flow through said flow passage between the fluid inlet and the fluid outlet, said valve stop member being located in the valve seat under the action of gravity when the valve is in its second state due to rotation of the coupler into its working orientation, preventing the flow of fluid between the fluid inlet and the fluid outlet, said valve stop member being moveable within said flow passage into and out of said valve seat under the action of gravity, wherein the flow passage is substantially L-shaped having first and second sections arranged perpendicular to one another, the fluid inlet being provided in a side wall of said first section of the flow passage and the fluid outlet being provided at one end of the second section of the flow passage, said valve seat being provided at said one end of the second section upstream of the fluid outlet.