Exact constraint arrangement for and methods of mounting an element such as a lens

An arrangement for mounting an element having a clearance-free and exact centering fit on an element holder, comprising:

• a generally cylindrical element holder having three radially disposed projections each having a firs side and a second side facing opposite the first side, the three radially disposed projections being positioned proximate an inner diameter surface of the cylindrical element holder;
• a generally circular element adapted to fit inside of said element holder in a manner to provide a clearance therebetween, said element having three radial faces proximate an outer diameter portion thereof to match the three radially disposed projections of said element holder;
• and
• means for seating the three radial faces of said element against the three corresponding radially disposed projections of said element holder by providing a translational force such that two radially disposed projections contact two corresponding radial faces with the first sides thereof and the third radially disposed projection contacts one of the radial faces with the second side thereof to automatically center said element within said element holder.

An arrangement for mounting an element having a clearance-free and exact centering fit on an element holder, comprising:

• a generally cylindrical element holder having three radially disposed projections proximate an inner diameter surface thereof;
• a generally circular element adapted to fit inside of said element holder in a manner to provide a small clearance therebetween, said element having three radial faces proximate an outer diameter surface thereof to match the three radial projections of said element holder;
• and
• means for seating the three radial faces of said element against the three corresponding radially disposed projections of said element holder by providing a torque such that the radially disposed projections contact corresponding radial faces on the same side to automatically center said element within said element holder.

An arrangement for mounting a lens having a line of focus in a lens holder having an axis which is an optical axis with which the line of focus of the lens aligns with precision, comprising:

• three abutments on the lens holder spaced 120.degree. apart with respect to the optical axis;
• three radial faces on the lens spaced 120.degree. apart with respect to the line of focus of the lens;
• and
• means for causing relative movement between the lens and lens holder after the spaced abutments and radial faces are brought into proximity with one another by mounting the lens on the lens holder to bring each radial face into engagement with an abutment, whereby the line of focus of the lens aligns with the optical axis defined by the lens holder.

An arrangement for mounting a pair of lenses in a lens holder, each lens having a line of focus passing through a center thereof, and the lens holder having an axis which is an optical axis with which the centers of the lenses align with precision, comprising:

• a set of three first abutments on the lens holder, the first abutments being spaced 120.degree. apart with respect to the optical axis;
• a set of three second abutments on the lens holder, the second abutments being spaced 120.degree. apart with respect to the optical axis and angularly spaced from the set of three first abutments;
• a set of three first notches on the first lens, each notch having a first radial face, with the resulting three first radial faces being spaced 120.degree. from one another with respect to the center of the first lens;
• a set of three second notches on the second lens, each notch having a second radial face with the resulting three second faces being spaced 120.degree. from one another with respect to the center of the second lens;
• means for initially bringing the first radial faces of the first lens into proximity with the first abutments on the lens holder and for bringing the second radial faces of the second lens into proximity with the second abutments on the lens holder;
• and
• means for causing relative movement between the lenses and the lens holder to bring each radial face into engagement with the abutment with which the radial face is proximate, whereby the centers of the lenses align with the optical axis defined by the lens holder.