LOCKING MECHANISM

Abstract: A locking mechanism specifically disigned for use on sliding doors and windows provided with narrow lock stiles which can be used to control a head bolt (16) and a sill bolt (15) and one or more bolt studs (8 and 9) on the leading edge of the door wherein a drive pinion (1) which may be controlled by a handle (22) is in meshing engagement with one and preferably two slide plates (4 and 5) to which the head and sill bolts (16 and 15) and the bolt studs (8 and 9) respectively are con­ nected. A locking cylinder (17) controls a lock plate (10) having means (43) thereon which is movable into a locking position into engagement with a recess (44) in the drive pinion (1) to deadlock the mechanism. An internal manual lock (11,46) may be associated with the lock plate (10) and an anti-slam device (51-67) is preferably provided to prevent the mechanism being deadlocked in its locked position when the door or window to which the machanism is fitted is open.

Description: LOCKING MECHANISM This invention relates to a locking mechanism designed for use on horizontal sliding doors and windows but which could be used in other applications to lock a movable member in a closed position. Many sliding doors, e.g. patio doors, have a frame for the glass which includes a lock stile, the width of which is small in relation to the overall width of the door. The minimum width of lock stile is dictated by the width of locking cylinder which is -a proprietary item and in the case of hollow metal box section lock stiles, the minimum internal width of the box section for most proprietary locking cylinders is about 31r;,m. The locking mechanism of this invention has been designed to fit into such minimum width lock stiles. With sliding doors and windows, security has always been a problem and there is now a requirement for multi-point locking, e.g. for there to be locking members provided at spaced locations around the periphery of the leading edge of the door. Ideally, to achieve this multi-point locking, head and sill bolts are provided but this still leaves the central leading edge portion of the door susceptible to forcing with a jemmy or other suitable object and it is preferred, therefore, that at least one further locking device is provided along the leading edge of the door at a central location. With the mechanism of the present invention, head and sill bolts and two locking devices can be provided, all activated by the same mechanism. According to the present invention, we provide a loc'tng mechanism, for use with sliding doors and the like, comprising a drive pinion mounted for rotational movement between front and rear support plates, at least one slide plate in meshing engagement with the drive pinion so that when the drive pinion is rotated in one sense, said at least one slide plate will slide in one direction and vice-versa, a bolt movable with the slide plate between a withdrawn inoperative position and and extended locking position, means associated with said .at least one slide plate and bolt for removably supporting a bolt stud so that in a position of use the bolt stud extends from the mechanism in a direction extending at right angles to the bolt and a lock plate mounted for sliding movement under the control of a locking cylinder between an inoperative position and a locking position in which it prevents rotation of the drive pinion. Preferably, two slide plates are provided, one located on each side of the drive pinion and in meshing engagement therewith so that rotation of the pinion in one sense will cause the slide plates to move in opposite directions, there being a second bolt associatec with the second slide plate. Preferably, a bolt rod carrier is supported on an end of each slide plate remote from its point of meshing engagement with the drive pinion to which a respective bolt is adjustably connected, one bolt comprising a head bolt and the other comprising a sill bolt. Preferably, each bolt rod carrier has a threaded passage therein extending at right angles to the longitudinal axis of the bolt to receive a threaded end of a bolt stud, there preferably being a friction pad interrupting the thread in said passage to lock a bolt stud screw-threadedly engaged in the passage at any suitable adjusted position. The bolt studs preferably have an enlarged head on their free end for engagement with a keep plate having keyhole shaped apertures designed for co-operation with the studs and for mounting on the frame for the door or window to which the mechanism is fitted. Preferably, the lock plate has an aperture therein for accommodating a boss of the drive pinion and projecting into this aperture from its periphery is a locking lug which engages in a suitable recess in the drive pinion or between its sprocket teeth, preferably only when the or each bolt is in an extending locking position. Preferably, the locking plate has a tail for engagement with a cam on the locking cylinder at one of its ends and at its opposite end a pair of detents engageable by a leaf spring to hold the plate in either its locking or unlocked position. Preferably, an aperture is also provided in this end of the plate for engagement by one end of a pivotally mounted locking snib which can be used manually to deadlock the mechanism if the locking cylinder can only be key-operated from one side, e..g. the outside. Preferably, the locking mechanism includes an anti-slam device to prevent the mechanism moving to a locking position when the sliding door or the like to which it is fitted is in an open position. The anti-slam device may include a plunger for mounting in the same leading edge of the door or the like in which the bolt stud is mounted, the plunger being biassed to a projecting position and having a cross pin for supporting the plunger for sliding movement in transverse slots in the front and rear support plates. Preferably, the cross pin is a rectangular bar which is provided adjacent each end with a reduced circular pin, the bar being slidable in a generally L-shaped slot in the or each slide plate, the shorter limb of the L-shaped slot extending transverse to the direction of movement of the or each slide plate and being so situated that when the slide plate is moved to its withdrawn inoperative position, the shorter limb is so located as to allow the plunger to move under its spring bias to its projecting position such that the rectangular bar can move from its normal position within the longer limb of its L-shaped slot into the shorter limb, the plunger thus preventing the or each slide plate from being moved to its locking position until the door is moved to a closed position, whereupon the plunger will engage a jamb for the door, and be moved back to a withdrawn position as the door moves towards the jamb, thus moving the rectangular bar out of the shorter arm of the slot so that the or each slide plate can be moved so that the bolt can be moved to a locking position. A preferred embodiment of locking mechanism according to the invention is- now described by way of example with reference to the accompanying drawings, in which: FIGURE 1 is a side elevation of the mechanism showing a head and sill bolt in a locking position; FIGURE 2 is a front elevation corre-sponding to Figure 1 but with a front plate removed and showing a pair of lock studs mounted on the mechanism; FIGURE 3 is a view similar to Figure 2 but showing the mechanism in an unlocked position, FIGURE 4 is a view corresponding to Figure 2 but with a front drive plate removed and showing a locking cylinder and lock plate in a locking position, and FIGURE 5 is a front elevation of the assembled mechanism corresponding to Figure 3. Referring to the drawings, the mechanism includes a drive pinion 1 rotatably supported between a front plate 2 and a rear plate 3 by means of stepped hubs 31 and 32. The drive pinion has a plurality of castellated drive teeth 33 spaced apart around its circumference, the spacing corresponding approximately to the width of each tooth. The front and rear plates 2 and 3 are held in spaced relationship by suitable stepped fixing rivets 34 which themselves are hollow and have transverse bores 35 therein to assist with fixing the mechanism in a door stile. Slidably supported between the front and rear plates 2 and 3 are a pair of slide plates 4 and 5, the plate 4 sliding against the inside surface ofthe front plate 2 and having apertures therein to accommodate the stepped boss 32 and the rivets 34, and the plate 5 being similarly mounted for sliding movement against the rear face of the rear plate 3. Each of the plates 4 and 5 has a plurality of apertures 36 therein for meshing engagement with the teeth 33 on the pinion 1 so as to provide what is in effect a rack and pinion. Obviously, the exact construction of the rack and pinion arrangement could be different from that illustrated. It will thus be appreciated that when the pinion'l is rotated in one sense, by operation of a handle '22, secured thereto in known manner, the plates 4 and 5 will move apart and vice-versa. As. is apparent from Figures 2 and 3, rotation of the pinion 1 in a clockwise direction will cause the plates 4 and 5 to move from an extended locking position towards each other to a withdrawn unlocked position. At its end remote from its meshing engagement with the pinion 1, the plate 5 has a bolt rod carrier or block 7 connected thereto with which a sill bolt 15 is screw-threadedly engaged so as to be adjustable relative thereto. A transverse internally threaded bore 37 is also provided in the carrier 7 optionally to receive a bolt stud 9 having an enlarged head 38. The bolt stud 9 has an external screw-thread for engagement in the bore 37 and theamount by which it projects from the carrier 7 can be adjusted merely by screwing the stud into or out of the carrier so as to accommodate manufacturing tolerances in the door or window and its frame in which the mechanism is fitted, and the stud is held in any adjusted position by means of a friction pad 39 which interrupts the screw thread in the bore 37 in known manner. A similar bolt rod carrier 6 is supported on the slide plate 4 at its end remote from its meshing engagement with the pinion 1 and this adjustably supports a head bolt 16 and a bolt stud 8 in a similar manner to the bolt 15 and stud 9 Of course, both the head and sill bolts 15 and 16 may in fact be bolt rods having actual bolt members secured their ends (not shown) remote from the varrlers 6 and 7. Each of the bolt studs 8 and 9 is optional and if fitted each is arranged to co-operate with a keep plate (not shown) which would be fitted to a stationary frame member. This keep plate would incorporate a pair of generally keyhole shaped apertures facing in opposite directions, the large-portion of each aperture having a sizesufficient to allow the heads of the studs to pass therethrough when the door or window to which the mechanism is fitted is moved to a closed position, and the narrow portion of each aperture being sufficiently wide just to accommodate the shaft of each bolt stud with the enlarged head of the bolt stud riding in a hollow space behind the keep plate when the mechanism is moved to a locking position. The mechanism is designed with a deadlock facility operated by a traditional key-operated locking cylinder 17 which is held in position in the mechanism by a cylinder screw 18. As is customary, the locking cylinder has a cam 40 associated therewith and this is arranged to co-operate with a turned over end portion 41 of a lock plate 10 which itself is slidably supported on the hub 32 of the pinion 1, there being an elongated aperture 42 in the plate 10 for this purpose. Projecting into this aperture from teperipnery thereof is a lug 43 which can engage in a recess 44 in the pinion 1 when the pinion has been rotated to a bolt locking position. Alternatively, the lug 43 may be replaced by a different shaped lug which can be engaged between the teeth 33 on the pinion 1. At its end opposite the turned over portion 41, the lock plate 10 has a pair of spaced detents 45 therein, one of which can be engaged by a nose on a leaf spring 21 when the lock plate is in its released position and the other of which is engaged by the nose on the spring 21 when the lock plate is in its locking position. Also in this end of the plate 10 is an aperture 46 which may be engagedby the free end of an interior locking snib 11 which is provided if the locking cylinder 17 is only provided with an external key aperture. In this case, the locking snib 11 would be pivotally mounted in known manner by means of an axte 47 supported on the lock stile of the door indicated at 14 in Figure 1. A handle spaced is schematically shown 13 and the base plate for the handle 22 is shown at 12, there being suitable apertures therein to accommodate the snib 11. As can be seen from Figure .1, the locking snib is moved from its broken line position to its full line position to move the lock plate into a deadlocked position. It will thus be appreciated that a locking mechanism is provided which is extremely compact and capable of fitting in the smallest possible door stile which will also accept a standard key-operated locking cylinder. The mechanism is shown as fitted with head and sill bolts 15 and 16 and a pair of bolt studs 8 and 9, but it will be appreciated that any one or more of these may be omitted. It will also be appreciated that the bolt studs 8 and 9 could have different constructions, for example, they could have a hook shape rather than be provided with the enlarged heads 9. It will be appreciated that if a door or window to which the locking mechanism of the present invention has been fitted has been opened and, inadvertently, the person opening the window has operated the lock so that it is in a locking position1 the head and sill bolts and two bolt studs will be in a position in which they project from their respective edges of the door. If the door is then inadvertently slammed shut, damage could be caused either to the locking mechanism or to the keeper plates fitted to the door frame. This problem can be overcome with the locking mechanism of the present invention merely by providing ramps on the keeper plates for the head and/or sill bolts. This then means that if the door is slammed, as the head and/or sill bolt(s) strikes the ramp of its keeper plate, the head and/or sill bolt will be moved axially inwards towards the lock mechanism at the same time withdrawing the bolt studs into the mechanism. As a result, no damage occurs. This is a further advantage of the mechanism of the present invention which is not present in many multipoint locking mechanisms. In some instances, the head and/or sill bolts may not be provided, in which case a further anti-slam device is provided to prevent the bolt studs which have been - inadvertently moved to their locking position damaging the keeper plates if the door is slammed. Referring to Figures 2 to 4, it will be noted that a plunger 51 is slidably supported, so as to project through a leading face of the door (the same face from which studs 9 project), by means of a rectangular crossbar 61, the reduced circular ends 53 of which are slidable in slots 55 in the front and rear support plates 2 and 3. The plunger 51 is biassed to its projecting position (Figure 3) by a coil spring 59. Each end of crossbar 61 is arranged to be accommodated in an L-shaped slot 63 in each slide plate 4 and 5. The slots 63 have their longer limb 65 extending parallel to the direction of movement of the slide plates 4, 5, and their shorter limbs 67 extending normal to this direction. It will thus be appreciated that when the door or the like is closed, the tip of plunger 51 will bear against the door jamb (shown at 69 in Figure 4). The limb 65 is wider than crossbar 61 to allow for tolerances between the door and jamb 69. If the door is locked, the mechanism will be as shown in Figure 4. To open the door it must first be unlocked so as to move studs 9 to their unlocked position (Figure 3). This will cause the slide plates 4, 5 to be moved to their Figure 3 position, with the crossbar 61 at the junction of the limbs 65, 67 of the slot 63. When the door is opened, away from jamb 69, spring 59 will cause the plunger 51 to move to its extended position, this being possible because crossbar 61 can move into the limbs 67 of the slots 63. Once in these limbs 67 (see Figure 3), they will lock the slide plates 4 and 5 against inadvertent (or intentional) movement to their locking position, and hence the studs 9 cannot be moved to a position in which, if the door was slammed shut, they would damage their keeper plates. Once the door is slammed or shut, however, the tip of the plunger 51 will engage the jamb 69, thus causing the crossbar 61 to move out of the limb 67, to its junction.with limb 65 and this will then allow the slide plates 4 and 5 and hence studs 9 to be moved to their locking position (Figure 4).

Claims: CLAIMS: 1. A locking mechanism, for use with sliding doors and the like, characterised in that it comprises a drive pinion (1) mounted for rotational movement between front and rear support plates (2,3), at least one slide plate (4 or 5) in meshing engagement with the drive pinion (1) so that when the drive pinion (1) is rotated in one sense, said at least one slide plate (4 or 5) will slide in one direction and viceversa, a bolt (16 or 15) movable with the slide plate (4 or 5) between a withdrawn inoperative position (Figure 3) and an extended locking position (Figure 4), means (6 or 7) associated with said at least one slide plate (4 or 5) and bolt(l6 or 15) for removably supporting a bolt stud (8 or 9) so that in a position of use the bolt stud (8 or 9) extends from the mechanism in a direction extending at rights angles to the bolt (16 or 15) and a lock plate (10) mounted for sliding movement under the control of a locking cylinder (17) between an inbperative position (Figure 3) and a locking position (Figure 4) in which it prevents rotation of the drive pinion (1). 2. A locking mechanism according to claim I characterised in that two slide plates (4,5) are provided, one located on each side of the drive pinion (I) and in meshing engagement therewith so that rotation of the pinion (1) in one sense will cause the slide plates (4,5) to move in opposite directions, there being a second bolt (15 or 16) associated with the second slide plate (5 or 4). 3. A locking mechanism-according to claim 2 characterised in that a bolt rod carrier (6 or 7) is supported on an end of each slide plate (4 or 5) remote from its point of meshing engagement with the drive pinion (1) to which a respective bolt (16 or 15) is adjustably connected, one bolt (16) comprising a head bolt and the other comprising a sill bolt (15). 4. A locking mechanism according to claim 3 characterised in that each bolt rod carrier (6 or 7) has a threaded passage (37) therein extending at right angles to the longitudinal axis of the bolt (16 or 15r to receive a threaded end (9) of a bolt stud (8 or 9). 5. A locking mechanism according to claim 4 characterised in that a friction pad (39) interrupts the thread (37) in said passage to lock a bolt stud (8 or 9) screw-threadedly engaged in the passage at any suitable adjusted position. 6. A locking mechanism according to claim 4 or 5 characterised in that the bolt studs (8,9) have an enlarged head (38) on their free end for engagement with a keep plate having keyhole shaped apertures designed for co-operation with the studs.(8,9) and for mounting on the frame for the door or window to which the mechanism is fitted. 7. A locking mechanism according to any one offthe preceding claims characterised in that. the lock plate (10) has an aperture (42) therein for accommodating a boss (31,32). of the drive pinion and projecting into this aperture (42) from its periphery is a locking lug (43) which engages in a suitable recess (44) in the drive pinion (1) or between its sprocket teeth (33). 8. A locking mechanism according to claim 7 characterised in that the locking lug (43) can only engage with the drive pinion (1) when the or each bolt (lô or 15) is in an extended locking position. 9. A locking mechanism according to claim 7 or 8 characterised in that the locking plate (10) has a tail (41) for engagement with a cam (40) on the locking cylinder (17) at one of its ends and at its opposite end a pair of detents (45) engageable by a leaf spring (21) to hold the plate (10) in either its locking or unlocked position. 10. A locking mechanism according to claim 9 characterised in that an aperture (46) is also provided in this end of the plate for engagement by one end of a pivotally mounted locking snib (11) which can be used manually to deadlock the mechanism if the locking cylinder (17) can only be key-operated from one side, e.g. the outside. 11. A locking mechanism according to any one of the preceding claims characterised in that the locking mechanism includes an anti-slam device (51-67) to prevent the mechanism moving to a locking position when the sliding door or the like to which it is fitted is in an open position. 12. A locking mechanism according to claim 11 characterised in that the anti-slam device (51-67) includes a plunger (51) for mounting in the same leading edge of the door or the like in which the bolt stud (8 or 9) is mounted, the plunger (51) being biassed to a projecting position (Fig.3) and having a cross pin (53,61) for supporting the plunger for sliding movement in transverse slots (55) in the frost end rear support plates (2,3). 13. A locking mechanism according to claim 12 characterised in that the cross pin is a rectangular bar (61) provided adjacent each end with reduced circular cross pins (53), the bar 61 being slidable in a generally L-shaped slot (63) in the or each slide plate (4,5) the shorter limb (67) of the L-shaped slot (63) extending transverse to the direction of movement of the or each slide plate (4,5) and being so situated that when the slide plate (4 or 5) is moved to its withdrawn inoperative position, the shorter limb (67) is so located as to allow the plunger (51) to move under its spring bias (59) to its projecting position such that the rectangular bar 61 can move from its normal position within the longer limb (65) of its L-shaped slot (63) into the shorter limb (67), the plunger (51) thus preventing the or each slide plate (4,5) from being moved to its locking position until the door is moved to a closed position, whereupon the plunger (51) will engage a jamb (69) for the door and be moved back to a withdrawn position as the door moves towards the jamb (69), thus moving the rectangular bar out of the shorter arm -(67) of the slot (63) so that the or each slide plate (4,5) can be moved so that the bolt (16 or 15) can be moved to a locking position.

Inventors: CHRISTMAS, PATRICK ERNEST, SMITH, JOHN COLIN
Applicants: SCHLEGEL (UK) HOLDINGS LIMITED
Application year: 1984
Main classification: E05C9
IPC codes: E05B63, E05C9