Patent GB-190925683-A (GB)
Title: Improvements in Permutation Locks.
Inventor: WILLIS PERCY RICHARD JULIUS
IPC: E05B37/00
Filed: 1909-11-08
Granted: 1910-03-24
Abstract: 25,683. Willis, P. R. J., [Le Myre, J. E.]. Nov. 8. Locks, permutation.-In permutation locks of the type in which the disks are set by alternate backward and forward rotations of the knob, excessive play between the disks is eliminated, and the necessity for giving the knob more than one turn in either direction thereby obviated In the form shown, the combination is ascertained by the sense of touch, a spring nawl 16 engaging a toothed wheel 15 on the handle spindle, and the disks having to bo placed in an initial position before the setting-movement is begun. The driving-disk 20 is adjustably secured to the spindle, and carries a pin 23 for engaging a projection 34 on the second disk 28. The projection 34 is not rigidly fixed on the disk but is on a slide 32 frictionally mounted thereon, so that it is capable of slight radial motion. The slide 32 also carries a lug 35 for engagement with a fixed pin 51 on the third disk 47, or with a lug 56 on a slide 54 slidably mounted on the third disk, according to the position of the lug 35 on the disk 28. The slide 54 on the third disk also carries a projection 57, which engages a cam-groove 58 in a plate 59 fixed to the casing at the back of the mechanism. The groove 58 is concentric for the greater part, but has an eccentric portion 58<a> and a stop 58<b>, which forms the initial starting-point for the setting-movement of the disks. To unlock, the knob is turned to give the disks a clockwise movement from the point of view shown in the Figures. The knob turns the driver disk 20, the pin 23 of which engages the pin 34 on the disk 28 and turns the latter disk. If the slide 32 is in the position shown in Fig. 7, that is, with the pin 34 near the centre, the pin takes into the notch 24 on the disk 20 and securely locks the two disks together. After a slight rotation, however, the slide 32 is moved by coming into contact with a trip device 37 on the casing, so that the pin 34 is carried away from the centre. As the knob is turned, the lug 35 comes into contact with either the pin 51 or the lug 56, according to the position of the slide 32, and turns the third disk 47. As the knob nears the end of one rotation, the projection 57 on the slide 54 enters the eccentric portion of the slot 58 and moves the slide 54, so that the projection 56 is carried towards the centre. In its movement, the projection 56, which is notched to engage the lug 35, returns the slide 32 to the position shown in Fig. 7. In this position, the lug 35 is held between the pin 51 and the projection 56 on the disk 47, and the pin 34 is within the notch 24 on the disk 20, so that all three disks are secured together. The pin 57 then comes against the end 58<b> of the slot 58, and stops further movement of the knob in that direction, this being the starting- position for setting the disks. The movement of the knob is then reversed, all the three disks being carried round. After a short rotation, the pin 57, entering the concentric portion of the slot 58, causes the projection 56 to move away from the lug 35 and pin 51. The turning- movement is then stopped to leave the last disk at its proper position. By reversing the movement of the knob, the projection 56 having been moved out of the path of the lug 35, the last disk is left in its set position, the first and second disks alone moving. After more or less turning, the trip device 37 comes into action to move the slide 32 and carry the pin 34 out of the notch 24, so that, after the second disk has reached its set position, the knob can be again reversed to set the first disk 20. The trip device 37 is inactive when the disk 28 is turned in a counter-clockwise direction, simply riding over the end 36 of the slide and falling again by gravity. A pin 27 on the driven disk 20 engages a corresponding pin 30 on the disk 28, so that, should the driver in being set be moved slightly beyond its correct position, it carries the disk 28 with it and thus breaks up the combination, and necessitates the entire setting movement being repeated. The disks have notches 26, 29, and 48 respectively, which, when set, receive a tumbler 5 pivoted to the bolt. The bolt can then be withdrawn by turning the knob. A modified construction is decribed, in which the eccentric portion of the slot 58 is towards the centre instead of away from it, and the other parts are modified to correspond with the change in movement. Each disk is made in two parts to allow the combination to be changed, and the fixed plate 59 is secured by a pin 61 engaging one of a series of notches 60 therein, so that the starting-point for the setting movement of the disks can be altered for the same purpose. Modified forms of trip device 37 are described.