GB1316972A - Lock unit - Google Patents

Abstract

1316972 Locks MINNESOTA MINING & MFG CO 15 June 1970 [16 June 1969] 28945/ 70 Heading E2A A lock unit for use in a building structure 10 comprises a cylinder lock mechanism 15 adapted to be mounted in an opening in a building structure on two mounting plates 35, 40, a first 35 to be fixed relative to the structure and a second deformable plate 40 connected to the mechanism via a member 50 passing through the first plate whereby movement of the cylinder lock mechanism relative to the first plate deforms the second plate. As shown the second plate has spacers 44, 45, 46 thereon to maintain the plates in spaced substantially parallel relationship when the unit is mounted in the building structure, the spacers being on a surface of the second plate to allow deformation thereof in a predetermined manner in response to movement of the cylinder lock mechanism. The spacers 45, 46 are parallel to each other and both being at right angles to the spacer 44; there are two openings for two members 50 which are in the form of mounting screws in the second plate 40, the two openings being in the portion of the plate between corresponding ends of the spacers 45, 46 and the spacer 44, thus when the forces applied to the screws to cause the second plate to become deformed the plate tilts on the tips 52 of the spacers 45 and 46 causing the portion to move away from the plate 35 and this engages a pivoted housing 20 and tilts it so causing the housing which is engaged with a switch to move a part 27 to abut a part 30 so that signal generating means is energised to give an alarm. The housing 20 supports a slidable bolt in such a way that any pressure on the door pivots the bolt to operate the switch. The force applied to the screws is caused if an attempt is made to prise the cylinder lock mechanism from the door. In a modification the plate 35 has a dished portion which engages in the bore 16 containing the cylinder lock mechanism to locate the plates relative to the bore.