Patent GB-1215010-A (GB)
Title: Security system
IPC: E05C17/36
Filed: 1967-11-22
Abstract: 1,215,010. Burglar alarms. GENERAL ALARM CORP. 22 Nov., 1967 [25 Nov., 1966] No. 53062/67. Heading G4N. [Also in Divisions E1, E2 and H1] A security system for a closure 10, said system comprises a bolt 19, 75 means supporting said bolt for slidable movement between projected and retracted positions and for tilting movement upon the application of a predetermined lateral force to said bolt, means urging said bolt into the projected position, means for retracting said bolt, bolt receiving means 50 or 87a and an alarm circuit activating switch 47, 81, and switch operating means effective to operate the switch upon said tilting movement of said bolt. In the construction shown in the bolt supporting member is a pin 42 projecting from one wall of a casing 15 which contains the bolt, the pin 42 passing through a slot in the bolt, the bolt carrying a cap 41 which contains a spring 44 trapped between the base of the cup and a head of the pin 42; the pin 42 can be adjusted by rotation to preset the force of the spring 44 and hence the amount of force required to tilt the bolt. The means for urging the bolt into its projected position are a pair of springs 20 trapped between an end of the bolt and an end of the casing. The means for retracting the bolt comprise a series of followers 21, 22, 24 operable by rotation of an outer knob, a key operated cylinder lock mechanism or an inner knob 12 respectively; the follower 21 has a flat sided groove 25 which receives a closely fitted square shank 14a of the outer knob so that the follower 21 rotates with the knob the follower 24 is similarly connected to the inner knob which has a square shank 12a. The outer knob shank 14a has a longitudinal bore 12b extending therethrough and a smaller square shank 27 rotatable by the key operated cylinder lock mechanism projectsthrough the bore 12b, central openings in the followers 21, 22 and fits closely into a square hole 29 of a segment 30 positioned between follower 21 and 24 and which is provided with a tab 31 that engages a wing of follower 22 to urge the follower into bolt retracting movement when the key cylinder is rotated in a particular direction. The followers are contained in an opening formed in a bolt extension so that rotation of any of the followers will retract the bolt against the force of the springs 20. A turn button 34 disposed adjacent the inner knob 12 is secured to a shaft 32 which carries a catch 35 having an opening with a large zone 35a and a small zone 35b opening into each other and positioned so that the small zone can be disposed to closely fit around three sides of the shank 14a of the outer knod to prevent its rotation; rotation is permitted when the turn button moves the catch so that the shank 14a is in the large zone 35a. Also disposed adjacent the inner knob is a slidable pin 37 controlled by a button 37a and the free end portion of which can be disposed in a groove 36 in the bolt 19 when the bolt is in its projected position so that the bolt cannot be retracted until the pin 37 is moved out of the groove 36. The switch 47 is operated when the bolt is tilted by a flange 46 of the bolt which deflects a control arm 49 of the switch. In the projected position the bolt is engageable with the running means 50 which is releasably mounted in door jambs 11; the means 50 has an integral ramp 51 which is engageable by the bolt upon closing movement of the door to retract the bolt automatically as the door is closed the springs 20 in the closed position of the door projecting the bolt into a recess in the means 50; the bolt carries a dead-locking member 55 which is mounted in the bolt 19 for pivotal movement about a vertical pin 56; the member 55 has a pointed projection 57 having a ramp 57a at its end which is disposed in the casing 15 and a tub 59 having end ramp 59a at its outer end portion; as the bolt 19 moves towards the projected position the ramp 57a engages a block 60 within the frame 15 and this pivots the member 55 after the tab 59 has entered the means 50 so that the tab 59 becomes engaged with a flange 54a of the means 50 so that the bolt 19 and means 50 are locked together against separation. Upon retraction of the bolt 19 the ramp 57a moves away from the block 60 and a ramp 59a of the tab 59 moves the member 55 counter clockwise by engagement with the flange 54a so that the bolt 19 is released from the means 50. The means 50 is held in position in the door jamb by a latch 52 slidable laterally in a slot 56 formed in a mounting member 57b against the force of a spring 59b; thus by moving the latch 52 to releasing position by means of a knob 54 the means 50 is released from the door jamb and the door can be opened while the bolt 19 is still locked to the means 50 by the member 55; a chain 61 is attached by one end portion to the means 50 and extends through chain anchor means 62 disposed in the door frame so that the door can only be opened to a limited extent. Since the means 50 is still locked to the bolt any pressure on the door in the opening direction when its movement is limited by the chain will tilt the bolt to operate the switch. In an alternative construction Fig. 9 and 12, the bolt 75 is a latch bolt which is carried by a barrel 77 which contains a spring to urge the bolt to projected position the barrel is secured to a plate 70 which is contained in a recess in a plate 67 through which the barrel 77 passes, the plate 70 carries a pair of threaded bolts which pass through the plates 67 and support springs 72 acting against the rear of the plate 67 the springs being held on to the threaded bolts by nuts so that the pressure of the springs is adjustable; the arrangement permits the plate 70 and hence the barrel and the latch bolt to tilt relative to the plate 67 which in use is secured to the end face of the door. Also disposed in the barrel is a deadlocking bolt 76. The rear end portion of the bolt 75 has a T- shaped projection which engages retracting mechanism of a known kind which includes two handles 64, 65. The barrel 77 at the end portion remote from the plate 70 has a collar 79 to which is connected an upstanding pin 80 and this is engageable with the switch 81 which is mounted on an arm 82 rigidly carried by the plate 67 so that any tilting of the bolt against the force of the springs 72 caused by pressure exerted on the door in the opening direction will cause the pin 80 to press the switch arm and close the switch to activate an alarm circuit; the plate 70 has an arm which extends beyond the plate 67 and mounts a headed button 84 in a slot 85 formed in a rearwardly extending flange 86 at the end of the arm. A chain 87 is connected by one end portion to the button 84 and passes through an anchor means 88 integral with the bolt securing means secured to the door jamb. The anchor means consists of a tube-like housing 86 integral with a striker plate 87, the housing 86 being closed by a plate 89 at its rear end formed with a crossshaped slot 90 through which the chain links can pass when they approach the plate in a more or less horizontal disposition. The plate 89 carries four upstanding projections 91 disposed around the slot and if the chain is bent either vertically or horizontally a link will abut two of the projections 91 to prevent further movement of the chain and hence of the door. Once movement of the chain is stopped by the projections further movement of the door tilts the bolt and operates the alarm switch.