Machinery guards

Claim 1

THE COMBINATION OF AN EXTENSIBLE SHAFT COMPRISING TELESCOPICALLY-ASSOCIATED SHAFT PARTS, THE RESPECTIVE SHAFT PARTS HAVING ANNULAR GROOVES OF PART-CIRCULAR CROSS-SECTION PROVIDING INNER BEARING RACES, TELESCOPICALLY-RELATED GUARD SHEATHS SURROUNDING SAID SHAFT PARTS AND EXTENDING ACROSS THE RESPECTIVE BEARING RACES, ANTI-FRICTION BEARING MEANS SEATED IN SAID RESPECTIVE BEARING RACES AND ADAPTED TO BE EXAPNDED CIRCUMFERENTIALY, A COLLAR SECURED INTERNALLY TO EACH SHEATH AND SPACED FROM THE RESPECTIVE BEARING MEANS IN THE DIRECTION TELESCOPING SAID SHEATHS, A NECK OF LESSER THICKNESS THAN SAID COLLAR BRIDGING BETWEEN SAID COLLAR AND SAID RESPECTIVE BEARING MEANS AND INTEGRATING EACH WITH THE OTHER, SAID NECK PERMITTING FLEXURE OF SAID RESPECTIVE BEARING MEANS RELATIVE TO SAID COLLAR, AND RESILIENT MEANS ENGAGING CIRCUMFERENTIALLY ABOUT SAID RESPECTIVE BEARING MEANS AND CONSTRAINING SAME TO SEAT IN SAID RESPECTIVE BEARING RACES, THE RESPECTIVE RESILIENT MEANS BEING ADAPTED TO BE OVERCOME BY A SHARP AXIAL PULL ON THE RESPECTIVE SHEATH IN THE DIRECTION TELESCOPING SAID SHEATHS THEREBY TO UNSEAT SAID RESPECTIVE BEARING MEANS AND PERMIT WITHDRAWAL ALONG THE RESPECTIVE SHAFT PART OF SAID RESPECTIVE SHEATH TOGETHER WITH SAID RESPECTIVE BEARING MEANS THUS TO EXPOSE SAID RESPECTIVE BEARING RACE.