436,964. Permutation locks. DIMOVIC, N., 83, Duke Street, Grosvenor Square, London. April 21, 1934, No. 12088. [Class 44] A keyless lock of the kind wherein a number of coupling elements laterally adjustable independently of each other and provided with projections and openings are movable together longitudinally to effect unlocking when set to the correct combination, has its coupling and bolt elements carried by three holders two of which enclose the third one which is movable longitudinally within the other two, the first two parts being connectible or disconnectible for securing the lock to, or detaching it from, a door or other article only when the third holder is in the coupled position and the door &c. is consequently unlocked. One of these two holders carries sets of adjustable coupling elements and the other one or more bolt members. An outer member 1 is adapted to receive a series of rings 2, 3, 4, 5, which may be coned as shown so that when inserted from the back they cannot be pushed right through. Each ring has one deep recess such as 5<a>, and a number of shallow recesses, as shown, in its rear surface. The rings are held in position by a radially slotted plate 6 held in place by a distance-piece 7, both the disc and distance-piece having peripheries of polygonal form to fit a correspondingly shaped inner surface on a recessed part of the member 1. Between the plate 6 and the rings is a spring plate 20 having four shallow projections to engage the recesses in the rings to prevent accidental movement. Carried by a member 8 shaped peripherally to fit the distance piece 7 are four polygonal rings 9, 10, 11, 12 fitting one within the other. Each of these rings carries a single projection, such as 9<a>, and all four rings are held in position by a slotted cover plate 13 clamped to the member 8 by a shouldered handle member 14 and a screwed cam member 15. The rings 9 .. 12 are originally set in any desired position and the member 8 can only be moved towards the member 1 when the deep recesses in the rings 2 .. 5 are brought opposite to the corresponding projections on the rings 9.. 12. A rear member 16 carries a sliding bolt 19 through which the cam member 15 passes so that the bolt is withdrawn against the pressure of a spring 18 when the cam is moved towards the front of the lock by the handle 14. The member 16 is screwed on to the member 1 to clamp the lock on to a door &c., but the necessary relative rotation can only take place when the member 8 is wholly within the member 1. At other times its polygonal edge engages the polygonal interior of a bolt-retaining disc 17 which is grooved to take the bolt 19. Instead of being screwed on, the member 16 may have a bayonet slot connection with the member 1 capable of being engaged in various positions to vary the direction of movement of the bolt 19, and instead of forming polygonal edges on the parts, keyway connections may be provided to prevent relative circumferential movement. Instead of using rings 9..12 the plate 13 may be formed with a series of holes through which pins are inserted having heads retained against the member 8 by the plate 13. These pins may be removed when desired and stored within the space between the plate 13 and member 8 so that the device can act as a simple latch. Additional recesses may be provided on the rings 2.. 5 out of the path of the projections on the rings 9 .. 12 these recesses being entered by projections on the movable holder corresponding at least in number to and of greater length than the other projections. Fig. 29 shows a modification in which rings 2, 3, 4 are in separable halves connected by pins and sockets, the deep and shallow coupling recesses being formed on the inner halves of the rings. In this case the member 8, pins 9, 10 &c., handle 14 and cam 15 are in one piece the combination being changed by varying the relative positions of the front and rear rings. This Figure shows two bolts 19, 19<a> movable in opposite directions. The device may be used as a small portable safe by forming a recess therein to receive small articles. Figs. 32, 38, 41 and 43 show a lock applied to the drawer of a desk in which the deep and shallow recesses are carried by four sliding bars 2 .. 5 in a member 1 and four headed pins are inserted through holes in the front of a member 8 and retained therein by a back plate 13 carrying a bolt member 19. A member 16 surrounds the members 1, 8 engaging grooves 1<a>, 8<a> therein and the parts are secured to the desk by a sliding plate 22 passed through slots 16<a> in the member 16. Normally the bolt member 19 engages holes in the plate 22 and a striking plate 23 on the drawer but when the slides 2 .. 5 are set to the correct combination the members 19 and 8 can slide upwards as the striking-plate 23 moves past the inclined edges of the bolt member 19.