Patent · US Expired

Drop ball sub-assembly for a down-hole device

US4796704A · kind A · utility

10Cited by
6References
9Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 4, 1987
Grant dateJan 10, 1989
Priority date
Expiry dateMar 4, 2007

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T137/7856
  • WIPO fieldCivil engineering
  • WIPO sectorOther fields

Abstract

A drop-ball sub-assembly comprises a tubular casing (4) defining a flushing fluid flow passage adapted for coupling at one end (3) to an inlet pipe (1) and at the other end (23) to an outlet pipe (24). A drop-ball (17) supporting member (8) is secured within the casing (4) in the flow passage. Apertures (21) are arranged to allow fluid flow past the supporting member (8), and a further aperture (9) supports a blow-out device (13) supporting a drop-ball (17) on a side distal from the end (23). The blow-out device (13) and the apertures (21,9) are such that at a first, lower fluid rate from the inlet (3) to the outlet (23) end, fluid flows through said aperture (21) and the blow-out device is retained, and that at a second, higher flow rate the blow-out device (13) is blown out of the further aperture to release the ball (17) through the further aperture (9). The blow-out device suitably comprises a frangible disc.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.