Patent GB-605722-A (GB)
Title: Improvements relating to locking cylinders and keys
IPC: E05B29/10
Filed: 1945-09-06
Abstract: 605,722. Barrel locks. BROADBENT, S. Sept. 6, 1945, No. 23054. [Class 44] A cylinder lock comprises a barrel rotatable in a housing, a keeper plate sliding on the barrel and one or more wards slidably accommodated in the barrel, the keeper plate and wards being so arranged that when in locked position they prevent rotation of the barrel in the housing, and when moved by the key they disengage each other to permit rotation, the keeper plate being engaged and moved, preferably through a transfer bar sliding in the key slot, by the end of the key, and the wards engaged by grooves or ridges on the key, and spring means being provided to return the wards and the keeper plate to locked position when the key is withdrawn. The housing 1, Figs. 1 and 2, has a cylindrical bore, along which are formed slots 9. The barrel comprises a cylindrical part 2, with an integral flange 47 at the rear end, and at the front an extension 17 of square section, with rounded corners, with a frusto-conical part 23 at the front end. At the junction of the square and cylindrical parts of the barrel is formed an annular groove 18, the bottom of which is of a diameter equal to the distance between the sides of the square portion. A key slot 12 is formed in the square part, and at right angles to the key slot are cut slots to accommodate the ward plate 5. The plates, Fig. 13, are of rectangular shape with a lug 16 at one corner, and slots 15, differently located in each ward, in one side, and are slightly bowed so as to be frictionally held in the barrel. Mounted on the square part of the barrel is a keeper plate 4, Fig. 8, having lugs 8 which engage in the longitudinal slots 9 in the casing 1, and slots 11 in which engage the wards 5, and in front of the plate 8 and sliding in the key slot is a bar 3, shown in Fig. 10, which is forced along by the key and pushes the plate 4 along against a spring 6 until it registers in the groove 18. The key, Fig. 16, has ridges 34.which engage the lugs 16 of the wards, and shift them so as to align the slots 15 with the plate 4, allowing the barrel to be turned. On withdrawal of the key, the spring returns the keeper plate 4 and the bar 3 to their forward locked positions, and as the plate 4 moves forward it engages the lugs 16 on the wards and moves them forward. In the modified form shown in Figs. 6, 7, 17, the housing has two longitudinal slots 9 on the vertical centre line, and an annular recess 29 of equal depth. The barrel extension 17 is of circular section, and the key slot 12 is wider to accommodate a key, Fig. 17, having grooves 36, the ends of which engage lugs on the ward plates 5, Fig. 7, which project into the key slot. The keeper plate 4, Fig. 6, is of annular form, with tongues 8 sliding in the slots 9, and the bar 3 slides in the key slot and in the slots 9; when the key is fully inserted, the bar 3 registers with the annular recess 29, while the notches in the ward plates 5 register with the keeper plate 4, so that the barrel is freed to rotate. In a further modification, shown in Fig. 18, the housing has a parallel bore, terminating in a bevelled shoulder and a parallel part at the rear, with wide slots at each side, and two further slots 40 on the vertical centre line which are of constant depth for a short distance and then taper off to a point about mid-way of the housing. The front part of the barrel is cylindrical, and the rear part formed with four flat faces 48, with a cylindrical spigot 33 at the end, where it is retained in the housing by a pin 50. An eccentric pin 51 actuates the lock. Ward slots 14, annular groove 18, and keeper plate 4 are similar to those shown in Fig. 1, while the key slot, key and ward plates are as described with reference to Figs. 6 and 7. The transfer bar 3, shaped as shown, has a nose 42 which engages in a notch in the key as the bar is constrained to slide downwardly by reason of the sloping form of the upper slot 40, so that the key can only be extracted when the lock is in locked condition.