James T. Farrow - Grand Prairie TX William D. Vanderford - Irving TX Ernest E. Taylor - Irving TX
Assignee:
Dresser Industries, Inc. - Dallas TX
International Classification:
B23P 1904
US Classification:
29454
Abstract:
A rotary rock bit is provided having a lubrication system with an expansion space within the lubricant reservoir to accommodate changes in lubricant volume. A flexible diaphragm is located within the lubricant reservoir. The lubricant reservoir is filled with lubricant thereby moving the flexible diaphragm to a substantially completely filled position. A predetermined volume of lubricant is displaced from the lubricant reservoir by forcing a fluid through passage means in the reservoir cap, moving the flexible diaphragm and displacing a predetermined volume of lubricant thereby providing an expansion space within the lubricant reservoir.