Seal for a valve operator

Claim 1

A SEAL FOR A VALVE OPERATOR COMPRISING A CASING, A STEM ROTATABLY MOUNTED ON AND EXTENDING INTO SAID CASING, THE STEM HAVING AN ENLARGEMENT, THE CASING HAVING AN OUTWARDLY OPEN CHAMBER THROUGH WHICH THE STEM PASSES AND IN WHICH THE ENLARGEMENT IS DISPOSED, THE CHAMBER HAVING A REDUCED PORTION AT ITS BOTTOM IN WHICH THE LOWER PORTION OF THE ENLARGEMENT FITS AND HAVING AN INWARD PASSAGE RECEIVING THE PORTION OF THE STEM INWARDLY OF THE ENLARGEMENT, PACKING OF V TYPE WITH THE APICES OF THE V''S DISPOSED UPWARDLY SURROUNDING THE ENLARGEMENT ABOVE SAID REDUCED PORTION OF THE CHAMBER THE PACKING BEING DISPOSED BETWEEN AND IN CONTACT WITH THE OUTER PERIPHERY OF THE ENLARGEMENT AND THE INNER WALL OF THE CHAMBER TO SEAL THE ENLARGEMENT TO THE CHAMBER AND INHIBIT LEAKAGE THEREBETWEEN, A THRUST COLLAR OUTWARDLY CLOSING THE CHAMBER AND ABSORBING THE OUTWARD THURST OF THE ENLARGEMENT WHEN THE STEM IS ROTATED, THE THRUST COLLAR HAVING INTEGRAL THEREIWITH A PACKING GLAND MAINTAINING THE PACKING IN PLACE, AND MEANS FOR FASTENING THE THRUST COLLAR TO THE CASING, THE ENGAGEMENT OF THE THRUST COLLAR WITH THE CASING LIMITING THE INWARD MOVEMENT OF THE PACKING GLAND AND THUS PROTECTING THE PACKING AGAINST OVERCOMPRESSION.