Abstract: A cap adapted to be detachably mounted to a camera lens, for example, comprises a locking member movable radially of the body of the cap, grooves formed in the body, and a spacer mounted to the locking member. The locking member has engaging legs, which are fitted in the grooves and can be resiliently deformed within spaces. After the locking member has been mounted to the body, the spacer occupies the spaces and prevents the deformation of the legs.

Abstract: In a removable coupling device between a photographic camera and an accessory of the type comprising at least two coupling pins secure to the camera and a coupling plate provided with key hole shaped opening to receive enlarged heads of the coupling pins and secured to the accessory, there are provided a sleeve bearing secured to the accessory, an operating shaft threaded into the sleeve bearing, a restoring spring for the operating shaft, an intermediate member threaded on the operating shaft and provided with a stop member, a locking frame pivotally supported by the intermediate member and provided with a member urged against one of the pins received in one of the key hole shaped openings when the operating shaft is rotated and an arm which when pushed by the operating shaft rotates the locking frame away from the pin and a spring for normally urge the locking frame against the coupling plate. Coupling members on the camera and the accessory can be interchanged.