US 3,969,984 A · Hydroacoustic apparatus and valving mechanisms for use therein

Abstract

Impact tools are described which are capable of developing percussive forces for rock drilling and other repetitive high force applications. A hydroacoustic oscillator contained in such tools includes a hammer and a valve mechanism which is actuated by the hammer for controlling the flow of pressurized fluid so as to establish pressure variations which sustain the oscillation of the hammer. A number of alternative valve mechanisms are disclosed, each including a valve element, the motion of which is controlled by controlling the flow of fluid with respect to the valve element as the hammer and valve element move relative to each other. Such flow control is afforded by chambers defined by the valve element; hydraulic fluid flow with respect to which is controlled so as to determine the deceleration of the valve element and the motion of the element in its actuation by the hammer.

Claims26

Dependent claims

For use in hydraulic oscillator apparatus in which a pressure actuated mass intermittently engages a valving element which is separate from said mass and is movable together therewith over a substantial portion of the trajectory of said mass to modulate the flow of fluid for producing pressure variations to sustain the oscillation of the mass, a valve mechanism which comprises means including said valving element for confining a volume of said fluid, and means for controlling the flow of said fluid into and out of said volume as a function of the position of said valving element as said element moves whereby to control the motion of said valving element and substantially eliminate any differences in the displacement of said mass and said element as they move together over said substantial portion of said trajectory.

A hydroacoustic oscillator operated by a source of pressurized hydraulic fluid having a supply and a return which comprises:

a housing having a longitudinal opening,
an oscillating mass in said housing opening and movable in opposite directions during each cycle of its oscillations,
said mass having a section extending to the wall of said housing opening and defining first and second cavities in said housing opening for said pressurized hydraulic fluid,
a valve structure in said first cavity including a valving element disposed entirely on the side of said mass section which defines said first cavity between the wall of said opening and said mass, and said valve element being separate from and movable relative to said mass for providing communication between said first cavity and said supply and said first cavity and said return during successive portions of each cycle of oscillation of said mass for sustaining the oscillations of said mass,
said valve element and one of said mass and the wall of said housing which defines said first cavity confining a volume of said fluid,
means operated by said mass for intermittently engaging said element after said mass moves over an initial portion of the displacement in each direction during each cycle of oscillation of said mass and then moves said element together with said mass over the remaining portion of the displacement thereof during each said cycle of oscillation of said mass, and
means for providing a path for the flow of fluid with respect to said confined volume for controlling the motion of said element as it is engaged and moves with said mass.

4 more elements

Dependencies are inferred from the claim text.

Hydroacoustic apparatus and valving mechanisms for use therein

Life of this patent

Hydroacoustic apparatus and valving mechanisms for use therein

Life of this patent

Abstract

Claims26