Internally expanding locking device for telescoped tubes

Claim 1

A SEAT ASSEMBLY COMPRISING A SEAT SUPPORT TUBE HAVING A SIDE OPENING NEAR ONE END, A STOP PLATE NEAR SAID END CONTIGUOUS WITH SAID OPENING AND EXTENDING INTO SAID TUBE, A BASE TUBE SURROUNDING SAID END AND SAID OPENING, A LOCKING DEVICE COMPRISING A FIRST MEMBER EXTENDING THROUGH SAID OPENING AND A SECOND MEMBER POSITIONED IN THE SEAT SUPPORT TUBE, EACH OF SAID MEMBERS HAVING A BASE, AN INCLINED SURFACE, AND A LOCKING SURFACE, THE BASE OF THE FIRST MEMBER SLIDABLY ENGAGING SAID STOP PLATE, THE BASE OF THE FIRST MEMBER BEING REMOTE FROM THE BASE OF THE SECOND MEMBER, THE INCLINED SURFACE OF THE FIRST MEMBER SLIDABLY ENGAGING THE INCLINED SURFACE OF THE SECOND MEMBER, THE LOCKING SURFACE OF THE FIRST MEMBER ENGAGING THE BASE TUBE, THE LOCKING SURFACE OF THE SECOND MEMBER ENGAGING THE SEAT SUPPORT TUBE OPPOSITE SAID OPENING, THE FIRST MEMBER HAVING AN INTERNALLY THREADED BORE EXTENDING FROM ITS BASE TO ITS INCLINED SURFACE, THE SECOND MEMBER HAVING AN OPENING EXTENDING FROM ITS BASE TO ITS INCLINED SURFACE, THE BORE IN THE FIRST MEMBER BEING IN ALIGNMENT WITH THE OPENING IN THE SECOND MEMBER, A BOLT HAVING A HEAD, A BODY AND A THREADED END, THE HEAD ABUTTING THE BASE OF THE SECOND MEMBER, THE BODY EXTENDING THROUGH THE OPENING IN THE SECOND MEMBER, AND THE THREADED END ENGAGING THE INTERNALLY THREAD BORE OF THE FIRST MEMBER, THE OPENING IN SAID SECOND MEMBER BEING SO CONSTRUCTED AND ARRANGED AS TO PERMIT MOVEMENT OF THE LOCKING SURFACE OF THE SECOND MEMBER AWAY FROM THE BOLT AS THE BOLT IS SCREWED INTO THE FIRST MEMBER.