GB569817A - Screwthread locking devices - Google Patents

Abstract

569,817. Locking nuts, &c. CHUBB, D. S. Sept. 16, 1943, No. 15231. [Class 89 (i)] A deformable washer for gripping a bolt &c. thread on screwing up and consequent flattening is initially a running fit on the thread with the wall of the hole parallel to the axis of the thread; the washer and nut are interlocked to prevent relative rotation. The washer may be coned as at 2 in Fig. 1, and be formed as a socket fitting the nut over a part of its polygonal surface or may be concaved as at 3 and extend over the full width of the nut as shown in dotted lines. In the latter case the thickness of the washer is such as to bring the exterior of the combined nut and washer up to the next convenient standard spanner size. The thickness should be at least one and a half times the thread pitch. Slits or slots extend from the inner edge part way across the washer to increase flexibility. As applied to an anchor nut the washer is shaped to fit the casing 11 which is cut away at 12 to permit replacement of the washer without removal of the casing. The nut may be counterbored at 6 so that the recess formed breaks through the flats of the nut to pass projections 7 on the washer. The projection 7 may be of pointed formation. In a modification larger washers are employed with triangular holes punched in to receive the projections left at the corners of the counterbored nuts. The nut and washer may be permanently assembled by making the hole a push fit for the projections or by burring the projections over.