GB1197263A - Improvements relating to Locking Mechanisms - Google Patents

Abstract

1,197,263. Locks. ILLINOIS TOOL WORKS Inc. 5 Nov., 1968 [15 Nov., 1967], No. 52434/68. Heading E2A. A lock mechanism adapted to be mounted in an apertured workpiece comprises a body member 50 having a bore therethrough, a panel assembly rotatably mounted in the bore and the body member having integrally formed axially spaced means for engaging opposite sides of the workpiece for securing the lock to the workpiece. In the construction shown the axially spaced means of the body member consist of a head portion 68 presenting a radially extending face for engaging one side of the workpiece which, as described, is a door panel and two resilient wing elements 90 and 92 which extend from a centre portion 72 of the body member, the free ends of the wing element having shoulder surfaces which engage the opposite surface of the panel to secure the body member in place. The aperture 4 in the panel is substantially rectangular in shape and the shank portion has a rectangular section immediately adjacent the head portion which fits in the aperture. To ensure a predetermined orientation of the body member 50 within the aperture, a key element 86 projects from the shank portion 72 for engagement with a notch in one edge of the apeture. The panel assembly consists of a tumbler mounting member 52, a number of wafer tumblers 54, 56, 58 which are inserted into chambers 108, 110 and 112 in the tumbler mounting member 52, cooperating springs 60, 62 and 64 for the tumblers which are also disposed in the chambers and a tumbler retaining member 66 which clips over an end section 106 of the member 52 to retain the tumblers and springs in place and to provide a guide for receiving a key and directing the key into the tumblers. The member 66 has a head portion 188 which overlies the outer end of the section 106 and the shank portion 130 which extends over an open side of the member 52 to cover the tumbler receiving chambers and it also has a resilient finger element 132 which terminates in an inturned hook 134 which extends into a notch formed in a side of the section 106 and which snaps into a slot for retaining the member 66 assembled with the member 52. The tumblers extend through slots 118, 120 and 122 for locking interengagement with pairs of oppositely disposed grooves in the inner wall of the body member 50, the lock having two locking positions at right angles to each other. The member 52 is provided with annular flanges 190 and 192 separated by a groove and an O-ring 196 is positioned in the groove for engagement with a cylindrical interior surface of the body member 50 for sealing the passageway through the body member. Additional annular flanges 198 and 200 are also provided by the member 52 which are spaced from each other by a reduced section, the flange 190 being spaced from the flange 192 by another reduced section. The innermost end flange 200 merges with a tapering cam surface 206 which facilitates assembly of the member 52 with the member 50 and the cam surface merges into a hook portion which includes an axially extending shank 208 and a laterally extending portion 210, the portion 210 being arranged to project through an aperture of a keeper member when turned to a door locking position. During assembly the hook portion 210 is first inserted into the bore of the body member, a slot 212 being formed in one side of the body member shank portion 72 to provide clearance for its end portion and to enable the member 52 to be pivoted into axial alignment with the member 50. The member 50 is then partially axially pushed into the bore until a catch formed on one side of the shank 208 has passed entirely through the member 50 and is in engagement with its end surface; to do this the catch passes through a narrow slit by spreading the slit; the cam surface 206 is at the opposite side of the portion providing the slit and hence the member 52 is held against axial displacement relative to the member 50 and the members are retained in partially assembled condition to form a unit which is easily handled. The final assembly of the lock mechanism with the door panel is accomplished by inserting the hook portion 210 through the panel aperture after which the body member 50 is pushed into the aperture until the wing elements 90 and 92 can expand behind the door; after the body member 50 is fully inserted the member 52 is forced axially into the member 50 causing the cam surface 206 to engage a shoulder of the body member 50 to expand the leading end portion of the shank portion 72, the shoulder snapping into the space between the flanges 198 and 200 to positively retain the members 50 and 52 in engagement so that they are rotatable relative to each other. At the same time the flange 192 of the member 52 is shifted into radial alignment with internal protruberances and of the wing element to prevent the wing elements being flexed inwardly so that the lock mechanism is permanently engaged with door panel. The members 50, 52 and 66 are formed from a plastics material such as nylon; when the lock mechanism is used for the door of a freezer this helps to prevent heat transfer through the mechanism.