Electrical switch lockable in one position

Claim 1

AN ELECTRICAL SWITCH INCLUDING A SWITCH CASE IN THE FORM OF AN OPEN-SIDED BOX, AN OPENABLE ACCESS DOOR FOR THE OPEN SIDE OF THE BOX, A PAIR OF CONTACT MEMBERS MOUNTED IN THE BOX AND RELATIVELY MOVABLE BETWEEN A POSITION IN WHICH THE SWITCH IS IN AN OFF STATE AND A POSITION IN WHICH THE SWITCH IS IN AN ON STATE, AN OPERATING MEMBER SITUATED EXTERNALLY OF THE BOX AND CONNECTED TO AT LEAST ONE OF THE CONTACT MEMBERS AND MANUALLY MOVABLE SO AS TO RELATIVELY MOVE THE CONTACT MEMBERS BETWEEN THE TWO SAID POSITIONS, FIRST INDICATING MEANS VISIBLE FROM A POSITION OUTSIDE THE BOX FOR INDICATING WHEN THE SWITCH IS IN THE ON STATE AND WHEN THE SWITCH IS IN THE OFF STATE, INTERLOCK MEANS SITUATED INSIDE THE BOX AND CONTROLLED BY THE OPERATING MEMBER SO AS TO ASSUME A FIRST POSITION WHEN THE SWITCH IS IN THE ON STATE AND A SECOND POSITION WHEN THE SWITCH IS IN THE OFF STATE, A LOCKING MEMBER SITUATED INSIDE THE BOX SO AS TO BE ACCESSIBLE ONLY THROUGH THE OPEN SIDE OF THE BOX WHEN THE DOOR IS OPEN AND MOVABLE BETWEEN A FREE POSITION AND A LOCKING POSITION, THE LOCKING MEMBER BEING MANUALLY MOVABLE INTO THE LOCKING POSITION ONLY WHEN THE INTERLOCK MEANS IS IN THE SAID SECOND POSITION SO AS TO THEN CO-OPERATE WITH THE INTERLOCK MEANS TO LOCK THE SWITCH IN THE OFF STATE, THE SWITCH THEN REMAINING LOCKED IN THE OFF STATE UNTIL THE LOCKING MEMBER IS MOVED TO THE FREE POSITION, AND SECOND INDICATING MEANS VISIBLE FROM A POSITION OUTSIDE THE BOX FOR INDICATING WHEN THE SWITCH IS LOCKED IN THE OFF STATE.