Abstract: This invention relates to flow pulsing methods and apparatus for various applications including downhole drilling equipment and in particular to an improved flow pulsing method and apparatus of this type to be connected in a drill string above a drill bit with a view to securing improvements in the drilling process.

Abstract: This invention relates to flow pulsing methods and apparatus for various applications including downhole drilling equipment and in particular to an improved flow pulsing method and apparatus of this type to be connected in a drill string above a drill bit with a view to securing improvements in the drilling process.

Abstract: Flow pulsing apparatus is adapted to be connected in a drill string above a drill bit. The apparatus includes a housing providing a passage for a flow of drilling fluid toward the bit. A valve which oscillates in the axial direction of the drill string periodically restricts the flow through the passage to create pulsations in the flow and a cyclical water hammer effect thereby to vibrate the housing and the drill bit during use. Drill bit induced longitudinal vibrations in the drill string can be used to generate the oscillation of the valve along the axis of the drill string to effect the periodic restriction of the flow or, in another form of the invention, a special valve and spring arrangement is used to help produce the desired oscillating action and the desired flow pulsing action.