| 摘要 |
A thin metallic blade or leaf of a photographic shutter, especially a shutter of the slit or focal plane type, is riveted to a trunnion which fits snugly but rotatably in an opening in a mounting plate. The trunnion has a circumferential groove intermediate its length, and the end of the trunnion remote from the shutter blade is of truncated conical shape. On the rear side of the mounting plate (the side remote from the shutter blade) there is a longitudinal groove extending tangent to the trunnion. A retaining wire in the longitudinal groove engages the circumferential groove in the trunnion, to retain the trunnion against being pulled axially out of its bearing opening in the mounting plate. In one form of the invention, the longitudinal groove for receiving the retaining wire is approximately twice the width of the retaining wire, and the wire is resilient and is held, at a distance from the trunnion, against the side of the wire groove which is toward the trunnion. The resilient wire may be sprung away from the trunnion to release the trunnion when the shutter blade is to be removed. When the shutter blade is being mounted on the plate, the frusto-conical end of the trunnion thrust the resilient wire aside and the wire snaps into the circumferential groove in the trunnion when the trunnion is fully seated in its bearing hole. In another embodiment, the groove for the retaining wire is only approximately the same width as the diameter of the wire, and the wire is moved longitudinally along its groove to engage in the circumferential groove of the trunnion or to disengage therefrom. |
