US 4,727,859 AGranted

Right angle detachable prism assembly for borescope

AssigneeWelch Allyn, Inc.

InventorRaymond A. Lia

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Abstract

A detachable prism assembly for a small-diameter borescope has a generally cylindrical housing with an open end that fits over a viewing head of the borescope, a prism, and a sliding prism holder within the housing. A spring urges the holder and prism proximally away from the distal end of the housing, and into contact with the front surface of the borescope head. The spring also urges a projection in the assembly into engagement with a corresponding recess in the periphery of the borescope viewing head. A manually actuable member on the detachable prism assembly must be moved by the user to move the projection out of engagement with the recess to permit detachment of the prism assembly from the borescope. The prism assembly can be attached only in its proper orientation, and cannot fall off the borescope head while in use.

Claims11

Dependent claims

A right angle detachable prism assembly for a small diameter borescope of the type that includes an insertion tube with a viewing head at its distal end, the head having a protruding member containing an optical image pickup device oriented along the axis of the head and through a flat front surface thereof, said protruding member having a peripheral cutout and radially projecting retaining means thereon;

the prism assembly comprising
a reflecting side-looking prism dimensioned to match said optical imager and having one flat face to be disposed against the flat front surface of the viewing head protruding member;
a generally cylindrical housing disposed over said prism and having an open proximal end to fit over the viewing head protruding member with cooperating means therein which engage said retaining means;
a prism holder slidably disposed in said housing including means securing said prism and oriented so that said one flat face is positioned against said protruding member front surface;
a proximally extending projection which engages said cutout in said viewing head protruding member when said prism flat face is disposed against said front surface;
means manually actuable from outside said housing to release said projection from said cutout;
and
resilient means for yieldably urging said prism holder proximally relative to said housing.

5 more elements

Dependencies are inferred from the claim text.