1317898 Padlocks HENRY SQUIRE & SONS 19 Oct 1970 [27 Sept 1969] 47626/69 Heading E2A In a padlock of the kind comprising a body containing a bolt and a key-operable mechanism for moving the bolt between locking and releasing positions in which it is respectively engaged with and retracted from a shackle 14 adjacent one end thereof, the shackle at its other end being pivotally secured to the body, the shackle 14 is formed with at least two notches 22, 23 at adjacent positions along the length thereof to accept respective nose portions 24, 25 formed on the bolt 11, the depth of each notch being such that the minimum cross-sectional area of the shackle in the notched region thereof is substantially greater than half the maximum cross-sectional area of the shackle. As shown, the padlock is constructed from a stack of inner and outer steel plates 8 and 9 secured together by rivets 19, 20, the hardened steel shackle 14 having a boss 18 through which extends a pin 15 having a bearing portion 15a received in the inner pair of outer plates 9 and end portions 15b of reduced diameter extending into the outer pair of the plates 9. The end of the shackle remote from the pin is rectangular in cross-section, and the centre line thereof extends along part of a circle the radius of which is centered on the pin axis. The bolt 11 is guided for movement between locking and releasing positions by slots 26 in the inner pair of plates 9 and has an upper face 28 which engages or is close to the upper face 29 of the cavity 10 formed in the plates 8; the lower side of the bolt is formed with ribs 30 which engage in notches 31 formed in plates 32 connected together in spaced parallel relation by a bolt stump 33. Each of the notches 22, 23 and the corresponding nose portions 24, 25 of the bolt have contacting faces 34a, 34b and 35a, 35b which are inclined at approximately 5‹ to the direction of movement of the bolt. The carrier comprising the side plates 32 and bolt stump 33 is guided for movement in a direction parallel to bolt movement by pegs 37 engaged in slots 38 in the plates and is normally held against movement by engagement of the stump at one or other side of the gates 39 of the levers 40 which are lifted against springs 56 by the use of a key engageable with recesses 57 in the plates 32. To avoid only partial closing of the shackle there is provided a guard lever 50 which includes a nose 51 projecting in the path of closure of the shackle and biassed by a spring 55 into an upward position wherein a projection 52 engages one of the pegs 37; the lever is formed with a gate 53 having a shoulder 54 so disposed that when the lever is in the operative position it is in the path of movement of the stump 33 and the carrier is prevented from movement by the key to an extent sufficient to enable the bolt to engage the shackle. Movement of the shackle to the closed position displaces the lever 50 so that the stump is free to move past the shoulder 54. The front outer plate 9 is formed with parallel guides for a rectangular keyhole cover plate assembled with the plate by a transverse strip of spring steel secured to the rear face of the cover plate and engaging under the guides.