Rotatable lamp means in moving or still picture projectors

Claim 1

A PICTURE PROJECTOR WHICH COMPRISES A PROJECTOR CASING HAVING AN OPENING, A LAMP HOUSING MOUNTED TO SAID PROJECTOR CASING AND HAVING A PIVOTABLE DOOR SWINGABLE BETWEEN OPEN AND CLOSED POSITIONS THROUGH THE OPENING IN SAID PROJECTOR CASING, A FIRST SPRING MEANS BIASING AND PIVOTABLE DOOR IN AN OPEN POSITION, A DOOR SLIDABLY MOUNTED ON SAID PROJECTOR CASING FOR CLOSING SAID OPENING AND HOLDING SAID SWINGABLE DOOR IN ITS CLOSED POSITION AGAINST THE ACTION OF SAID FIRST SPRING MEANS, A DISK MEMBER, MEANS ROTATABLY MOUNTING SAID DISK MEMBER ON AN INSIDE FACE OF SAID PIVOTABLE DOOR BETWEEN A FIRST AND SECOND FIXED POSITION, A SECOND SPRING MEANS BIASING SAID DISK MEMBER TOWARDS SAID FIRST FIXED POSITION, SAID PROJECTOR LAMP HOUSING HAVING AN APERTURE IN A WALL OPPOSITE SAID PIVOTABLE DOOR, A FIRST AND SECOND LAMP HOLDER, MEANS MOUNTING SAID FIRST AND SECOND LAMP HOLDER ON SAID DISK MEMBER AND ADAPTED SO THAT A FIRST LAMP MOUNTED IN SAID FIRST LAMP HOLDER WILL BE ALIGNED WITH SAID APERTURE IN SAID FIRST FIXED POSITION OF SAID DISK MEMBER AND SO THAT A SECOND LAMP MOUNTED IN SAID SECOND LAMP HOLDER WILL BE ALIGNED WITH SAID APERTURE IN SAID SECOND FIXED POSITION OF SAID DISK MEMBER, A FIRST ELECTRICAL CONTACT MOUNTED ON SAID LAMP HOUSING WHICH IS ENGAGEABLE WITH SAID SECOND LAMP HOLDER TO ROTATABLY ARREST IT WHEN SAID DISK MEMBER IS AT SAID SECOND FIXED POSITION ONLY WHEN SAID PIVOTABLE DOOR IS CLOSED AND ENGAGEABLE WITH SAID FIRST LAMP HOLDER ONLY WHEN SAID DISK MEMBER IS AT SAID FIRST FIXED POSITION AND SAID PIVOTABLE DOOR IS CLOSED, A SECOND ELECTRICAL CONTACT, AND MEANS MOUNTING SAID SECOND ELECTRICAL CONTACT MEANS TO ENGAGE EITHER A TERMINAL OF SAIF FIRST LAMP OTHER THANT A TERMINAL IN CONTACT WITH SAID FIRST LAMP HOLDER WHEN SAID DISK MEMBER IS AT SAID FIRST FIXED POSITION OR A TERMINAL OF SAID SECOND LAMP OTHER THAN A TERMINAL IN CONTACT WITH SAID SECOND LAMP HOLDER WHERE SAID DISK MEMBER IS AT SAID SECOND FIXED POSITION.