GB2134583A - Door lock - Google Patents

Abstract

A door lock comprises a conventional cylinder mechanism 'A' incorporating a body and a key operable core rotatable therein. A thrower arm 3 is rotatable with the core and engages in a slot 6 of a tail 4 of a dead bolt assembly which also incorporates bolt 8. A locking member 10 is pivoted at 11 to bolt 8 and has projections 12 engageable to either side of the cylinder 'A' by spring 15 when the bolt is in a locked or withdrawn condition to hold the bolt in such a condition. As shown, projection 12 is retracted from cylinder 'A' by thrower arm 3 in an intermediate position to allow sliding movement of the dead bolt assembly. Region 9 of the cylinder acts as a guide surface for tail 4. Tail plates 22, 23 are movable together with main bolt 8 by the engagement of their slots 26, with projections 21 on bolt-tail 4. These tail plates bear head- and foot-bolts for the door. <IMAGE>

Description

SPECIFICATION Door locks This invention relates to locks for doors and the like, and of the kind incorporating a "cylinder mechanism" having a key operated core rotatably mounted in an elongate body of uniform cross sectional outline, said core having a thrower arm which rotates therewith and, through an intermediate mechanism, imparts the requisite linear movements to one or more dead bolts to secure or release a door upon which the lock is mounted. The intermediate mechanism usually incorporates a pivotal member which is often of complicated construction and takes up considerable space.

It is the object of this invention to provide a lock which is compact and simple in construction.

According to the present invention the thrower arm makes direct engagement with a dead bolt and tail assembly which can slide linearly in a direction perpendicular to the axis of the cylinder mechanism, part of the restraint required for said linear sliding is obtained by arranging the tail to slide in controlled gaps between the cylinder body and lugs formed on the inside of the casing which houses the entire lock mechanism, the dead bolt and tail assembly carries a pivotally mounted locking member having projections which are spring loaded to make contact with one or other opposite sides of the cylinder body depending on whether the dead bolt is in the shot or withdrawn position.A lock may also include a second tail for a second dead bolt which slides linearly and concurrently with the first dead bolt but in a direction perpendicular to that of the first dead bolt and to the axis of the cylinder mechanism, part of the retraint required for its linear movement is due to the tail sliding in a controlled gap between the body of the cylinder mechanism and a member of the casing. Also, a third tail for a third dead bolt may be provided to slide linearly and concurrently with but in opposite directions to those of the second tail, part of the restraint required for its linear movement is due to said third tail sliding in a controlled gap between members of the casing.

One construction of a lock in accordance with the invention will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 is a side elevation of a lock with a side cover plate removed and the inner end of the third tail broken away to show the internal mechanism, in this view the dead bolts are fully withdrawn.

Figure 2 is a similar view to figure 1 but the dead bolts are in the fully shot position.

Figure 3 is a similar view to figures 1 and 2 but the dead bolts are in an intermediate position.

Referring to the drawings, the cylinder mechanism, indicated generally by the reference letter 'A' is shown with its longitudinal axis normal to the plane of the paper. The cylinder mechanism 'A' protrudes through two side cover plates, the more remote one being indicated by the numeral 1. The nearer side cover plate is not shown in the drawings, as already noted. A third plate 2, known as the forend is viewed "edge-on" in the drawings and is held in fixed relationship to the side cover plates. In practical applications the lock is accommodated in a pocket within the thickness of the door so that the cover plates are parallel to the major surfaces of the door and the outer surface of the forend is flush with the surface of the opening edge of the door.

The key operated central core (not shown) is provided with a radially extending thrower arm 3 which can engage with a first tail 4 to impart thereto a linear sliding motion which, as viewed in the drawings, can be either to the left to put the lock into the locked condition or to the right to put the lock into the released condition. In the drawings the engagement of the thrower arm 3 and the tail 4 is simply a matter of the thrower arm entering a rectangular aperture in the tail, said aperture having a left hand face 5 and a right hand face 6. To put the lock into the locked condition the thrower arm pushes against the left hand face 5 and to put the lock into the released condition the thrower arm pushes against the right hand face 6.In practice other forms of engagement could be used between the thrower arm and the tail, e.g. gear teeth on the thrower arm and rack teeth on the tail.

Horizontal surfaces 7 (see fig. 2) are provided adjacent the inner surfaces of the side cover plates and an aperture is formed in the forend to provide a sliding fit on the lateral surfaces of a first dead bolt 8 which is rigidly attached to the tail 4. The necessary constraint for the sliding motion of the assembled dead bolt 8 and tail 4 is provided by the fit of the bolt 8 in the aperture in the forend and by the fit of the tail between the surfaces 7 and regions 9 on the surface of the body of the cylinder mechanism 'A'. This is shown most clearly in fig. 2.

A locking member 10 is pivotally attached at 11 to the dead bolt 8 to permit an order of angular movement which can be seen by comparing fig. 3 with the other drawings. Two projections 1 2 are provided on the locking member 10 said projections being spaced apart so that the gap between them accommodates the thrower arm 3.

A cross member 1 3 is mounted in and between the side cover plates so that it is free to rotate about an axis normal thereto, said cross member has a transverse hoie which provides a slidable mounting for a plunger 14 one end of which is urged against locking member 10 by a spring 1 5 mounted on said plunger.

With the bolts in the withdrawn position the force of the spring 1 5 causes the left facing surfaces 1 6 of the projections 12 to wedge against the lower right regions 1 7 of the body of the cylinder mechanism, this is shown in fig. 1.

With the bolts in the shot position the force of the spring 1 5 causes the right facing surfaces 1 8 of the projections 12 to wedge against the lower left regions 1 9 of the body of the cylinder mechanism, this is shown in fig. 2. Said wedging of the surfaces 1 8 against the body of the cylinder mechanism "dead-locks" the bolt against movement towards the withdrawn position when pressure is applied to its end surface.

Each of the two side plates has a closed ended straight slot 20 disposed in a direction parallel to the travel of the assembled dead bolt 8 and tail 4.

The tail 4 is provided with two projections 21, one on each of its sides. Each of the two slots 20 accommodate its neighbouring projection 21. This arrangement limits the travel of the assembled dead bolt 8 and tail 4 and it also provides some rigidity to the dead bolt 8 when it is in the outer or shot position.

A second tail 22 is of generally flat construction and is positioned loosely against the inner surface of side cover plate 1. A third tail 23 is similarly constructed and similarly positioned with respect to the other side cover plate. Each of the tails carried at its outer end a block 24 having a threaded hole 25. Correspondingly threaded rods connect tail 22 to a second bolt at the top of the door and tail 23 to a third bolt at the bottom of the door. Each of the tails is provided at its inner end with a sloping slot 26, each of the two slots 26 engages its neighbouring projection 21 so that, as viewed in the drawings, horizontal movement of the assembled dead bolt 8 and tail 4 imparts vertical movement to the second and third tails 22 and 23, key operation can cause all three bolts to be shot or withdrawn at the same time.

The constraint for the linear movement of tail 22 is obtained from sliding contact at the face 27 of the forend and at the region 28 on the surface of the body of the cylinder mechanism 'A'.

The constraint for the linear motion of tail 23 is obtained from sliding contact at the face 27 of the forend and at the surface 29 of a cross member or boss 30 incorporated in the construction of the casing.

Starting with the mechanism in the withdrawn position shown in fig. 1, appropriate operation of the lock key will cause the thrower arm 3 to first make contact with the face 31 on the locking member 10, see fig. 3. Further rotation of the thrower arm 3 pushes the locking member 10 towards the position shown in fig. 3 and so moves the surfaces 1 6 away from the surface 1 7 of the body of the cylinder mechanism, thus the assembled dead bolt 8 and tail 4 is freed to be moved to the shot position. Continuing rotation of the thrower arm brings it into contact with the face 5 of the aperture in the tail 4 and causes the bolts to move towards the shot position. With still more rotation, the thrower arm 3 eventually loses contact with the edge 5 and begins to move away from the tail 4.Said loss of contact occurs just before the assembled dead bolt 8 and tail 4 have reached the end of their travel as would be determined by the projections 21 reaching the ends of the slots 20. At this stage the inclination of the spring 1 5 causes it to exert a component of force on the assembled dead bolt 8 and tail 4 in the direction of continuing travel and said component of force urges the bolts intro their fully shot positions, see fig. 2. The operation of the mechanism to withdraw the bolts is a reversal of the aforementioned procedure.

Before the occurrence of the aforementioned loss of contact between the thrower arm 3 and the face 5, the spring 1 5 has pushed the locking member 10 into a position near enough to that shown in fig. 2 to effect between the surfaces 1 8 on the locking member 10 and the surface zones 19 on the body of the cylinder mechanism 'A', a frictional lock which will prevent inward movement of the bolts in the event of inward pressure being applied thereon from the outside of the lock.

Claims (10)

1. A door lock comprising a cylinder mechanism incorporating a body and a key operable core rotatable therein; a thrower arm rotatable with the core; a dead bolt assembly slidably guided in the lock and movable between a locked and a withdrawn position by rotation of the thrower arm; and a locking member pivoted to the dead bolt assembly and engageable against the cylinder to constrain movement of the dead bolt from a locked position and being pivotal away from such engagement with the cylinder by rotation of the thrower arm in a withdrawal direction.

2. A door lock as claimed in claim 1 wherein the connections from the thrower arm to the dead bolt assembly and the locking member are such that initial movement of the thrower arm moves the locking member and subsequent movement thereof begins to withdraw the dead bolt assembly.

3. A door lock as claimed in claim 1 or claim 2 wherein the locking member is also engageable against the cylinder to constrain movement of the dead bolt from an unlocked position and is also pivoted away from such engagement with the cylinder by rotation of the thrower arm in a locking direction.

4. A door lock as claimed in claim 3 wherein the locking member incorporates a projection which is engageable on either side of the cylinder dependent on whether the lock is in its locked or withdrawn position.

5. A door lock as claimed in claim 4 wherein the locking member is spring-loaded towards the cylinder to engage the projection behind one side or the other of the cylinder.

6. A door lock as claimed in any one of the preceding claims wherein a surface of the cylinder acts as a guide surface for the dead bolt assembly.

7. A door lock as claimed in any one of the preceding claims including at least one further dead bolt assembly coupled to be removed by movement of the first mentioned dead bolt assembly and movable in a different direction from that of the first mentioned assembly.

8. A door lock as claimed in claim 7 including second and third dead bolt assemblies arranged to engage bolts in the upper and lower surfaces of a door.

9. A door lock asclaimed in claim 7 or claim 8 wherein a surface of the cylinder acts as a guide surface for the further dead bolt assembly or the second and third dead bolt assemblies.

10. A door lock substantially as described with reference to and as illustrated by the accompanying drawings.