Filter switching and bias adjusting means for use in a colorimeter

Claim 1

IN A COLOR MEASURING DEVICE INCLUDING A PLURALITY OF SELECTABLE OPTICAL FILTERS AND SIGNAL MEASURING MEANS, A FILTER SWITCHING DEVICE COMPRISING A SHAFT, A ROTATABLE MEMBER CARRYING A PLURALITY OF FILTERS THEREIN SECURED TO ONE END OF SAID SHAFT, A HUB SECURED TO THE OTHER END OF SAID SHAFT, A ROTATABLE POSITION ADJUSTING MEMBER MOUNTED ON SAID HUB AND AXIALLY MOVABLE RELATIVE TO SAID HUB, SPRING MEANS MOUNTED BETWEEN SAID HUB AND SAID ADJUSTING MEMBER, A SNAP RING ON SAID HUB TO LIMIT AXIAL MOVEMENT OF SAID ADJUSTING MEMBER, A PLURALITY OF ADJUSTING SCREWS LOCATED IN SAID ADJUSTING MEMBER, A POTENTIOMETER HAVING A SLIDE MOUNTED FOR SELECTIVE ENGAGEMENT BY SAID SCREWS, SAID POTENTIOMETER BEING ELECTRICALLY ENERGIZED TO SUPLY A BIASING SIGNAL TO THE SIGNAL MEASURING MEANS, AND MEANS FOR RESTRAINING SAID ADJUSTING MEMBER AGAINST ROTATION WHEN ONE OF SAID ADJUSTING SCREWS IS IN CONTACT WITH THE POTENTIOMETER SLIDE.