| (19) |
 |
|
(11) |
EP 0 191 608 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
|
27.07.1988 Bulletin 1988/30 |
| (43) |
Date of publication A2: |
|
20.08.1986 Bulletin 1986/34 |
| (22) |
Date of filing: 06.02.1986 |
|
|
| (84) |
Designated Contracting States: |
|
DE FR GB NL SE |
| (30) |
Priority: |
09.02.1985 GB 8503382
|
| (71) |
Applicant: The British Petroleum Company p.l.c. |
|
() |
|
| (72) |
Inventors: |
|
- Clarke, Roy Dugmore
()
- Newman, Robert Henry
()
- Pike, William Carill
()
|
|
| |
|
| (54) |
Lubricating grease for rock drill bits and bits so lubricated |
(57) @ A lubricating grease suitable for use in rock drill bits comprises:
(1) a major proportion of a mineral or synthetic hydrocarbon base oil,
(2) from 3 to 15% wt by weight of the grease of a lithium complex soap as the sole
thickener, and
(3) from 5 to 20% wt by weight of the grease of molybdenum disulphide particles as
extreme pressure additive.
Such a grease has the required lubrificating qualities and the required flow properties
for use in rock drill bits having a grease reservoir (e.g. a pressure equalisation
chamber) and channels connecting the reservoir to the bearing surfaces.