Washer assembly for an inflatable friction bolt

摘要

WASHER ASSEMBLY FOR AN INFLATABLE FRICTION BOLT A washer assembly for an inflatable friction bolt (1) which has an enlarged head (3) comprising a first washer element (10) which has a semi-spherical leading face (11), an 87 opposing trailing face (12) and a first aperture (13) extending between the leading face (11) and the trailing face (12). The first aperture (13) has an enlarged trailing section (15) opening onto the trailing face (12) defining a recessed annular shoulder for engaging the enlarged head (3) of the friction bolt (1). The washer assembly further comprises a second washer element (20) that has a plate portion (21) and a boss (22) projecting from /O the plate portion (21). The boss (22) has a circular rim (23) for engagement with the leading face (11) defining a second aperture (24) extending through the second washer element (20).