Patent ID: 8348578

Claim:
An engagement unit for insertion onto, and engagement with, a threaded bolt, said engagement unit comprising: an inner part, said inner part including spring arms having latches engagable with the threaded bolt; an outer part, said outer part slidable onto said inner part along an insertion direction to a final assembly arrangement in which said spring arms are blocked radially outwardly against movement by spring arm seats formed on said outer part, said outer part further including an application head adapted for engagement by a torque-applying tool; said inner part and said outer part including mutually engaging, torque resistant structures which, in said final assembly arrangement, are in engagement with one another to prevent relative rotation between said outer part and said inner part; and said inner part and said outer part including a latching arrangement which, in said final assembly arrangement, fixes said outer part onto said inner part, said latching arrangement including latching hooks configured on said inner part and latching recesses configured on said outer part; said latching hooks engaging said latching recesses in said final assembly arrangement; and said latching recesses extending through, and open externally of, said outer part, and said latching hooks accessible externally of said outer part through said latching recesses in order to release said latching hooks from said latching recesses.