Patent GB-424120-A (GB)
Title: Improvements in locking devices for safety purposes
IPC: E05B19/00
Filed: 1933-05-09
Abstract: 424,120. Locks; electric switches. FUTRAN, S., 40, Alexanderstrasse, Berlin. May 9, 1933, Nos. 13446 and 13447. Convention dates, May 9, 1932 and Sept. 29, 1932. [Class 44] [See also Group XXXVII] In a change-key lock having mechanism of permutation type which can only be unlocked by a key like that with which it was locked, the locking may be effected by repeated use of the key, with or without a change in the setting of the key between successive operations. Figs. 1-3 show a form operated by rotating key in which a number of rotatable discs 1 having flats 11, which must be registered with the face of a keeper 10 to release the lock, are stepped round selectively by keybits engaging gaps 7 in the edge of a central aperture. One step is effected with each rotation of the key, which, in one form, has bits in the form of pegs or screws which can be selectively placed in a series of apertures extending along the stem of the key. When a disc is displaced from release position its unmutilated periphery engages a recess in the keeper. An application is described in which the discs engage recesses in a sliding bolt to prevent its operation. Spring members 6 are adapted to snap into recesses 5 to hold the discs against accidental displacement. In the Specification as open to inspection under Sect. 91 one of these recesses in each disc was made in an inset piece of insulating material so that operation of the discs effected closure of an alarm circuit. This subjectmatter does not appear in the Specification as accepted. Fig. 8 shows a modified form of key in which a square stem has mounted thereon a number of discs 8<a>, with circular apertures so as to be freely rotatable, alternating with discs 8<b> fitting the stem to rotate therewith. The bits 8 are mounted in undercut grooves so that they can be selectively slid into engagement with either idle or fixed discs. Fig. 10 shows a modification operated by insertion of a non-rotating key, which selectively moves slides 16 having rack teeth engaging toothed discs 8. A slide 10 the upper portion of which, when raised, enters a recess in bolt 2, to lock it, falls to effect release when a cross-bar 9 on the slider is able to enter registered recesses 12 in the series of discs, these recesses being formed in the edge of a central aperture by which the discs are rotatably mounted on a spindle recessed to receive the cross-bar 9 when the slide is raised. Four sets of recesses 12 are shown and movement of each disc is limited to one direction by a pawl 15 so that when a disc has been moved to locking position release is effected by further movement in the same direction. This allows use of a double-ended key such as is illustrated in Fig. 12 one end being used for locking and the other for releasing. The key has adjustable slides each with two projections 19 a fixed distance apart so that when a slide is adjusted to place one projection the required distance from the locking end of the key, the other is automatically adjusted at the correct distance from the other end for unlocking. As shown there are seven teeth between consecutive recesses 12 so that when a disc has been moved two steps from release position, it is again brought to release by moving a further five steps. Thus by adjustment of one projection 19 two steps from one end of the key the other is automatically placed five steps from the other end. The bolt 2 when released may be operated by a knob 3 and two keyholes 28 with two sets of slides 16 may be provided, as shown, so that operation may be effected from either side.