GB2353324A - Deadbolt with increased throw - Google Patents

Abstract

A cylinder mortice lock has a lock case 10 which a deadbolt 12 extends out of or retracts into. The lock cylinder has a cam 15b which engages a bolt moving member on key operation in one direction, to retract the bolt 12, and engages the deadbolt 12 on key operation in the opposite direction to extend the bolt. The bolt moving member has a part engaged with the deadbolt 12 and a projection received in an arcuate slot 16 in the lock case along which it travels to guide movement of the member 31. The arrangement of the bolt moving member allows increased deadbolt throw with a relatively small lock case.

Description

2353324 LOCK The present invention relates to a lock, particularly a

cylinder mortice lock, having a deadbolt, extension and retraction of which is effected by rotation of the cylinder key in respective opposite directions.

in one type of cylinder mortice lock, a cam of the cylinder lock acts directly on the deadbolt, normally on a lath thereof, both to extend and retract the deadbolt out of and into the lock case. With this arrangement, it is not possible to produce the larger throw of the deadbolt which is now required with such locks.

Another way of achieving increased deadbolt throw is to provide an auxiliary member which is acted on directly by the cylinder cam, and which itself acts on the deadbolt lath both to extend and retract the deadbolt. A problem with this arrangement is that with smaller lock cases it is difficult sufficiently to support the auxiliary member rigidly so that it can provide the required force to throw the deadbolt. Moreover there is a problem with a build up of tolerances which can lead to operational difficulties.

An object of the invention is to provide an improved lock.

According to the invention a lock comprises a lock case, a lock cylinder carried by the lock case, a cam of the lock cylinder, a bolt arranged to extend and retract out of and into the lock case, in use, and bolt moving means, the cam, in use, engaging one of the bolt and the bolt moving means in one direction of rotation of a key of the lock cylinder to extend the bolt, and engaging the other of the bolt and the bolt moving means in the other direction of rotation of said key to retract the bolt.

Preferably the cam engages the bolt to extend it, and engages the bolt moving means to retract it. Desirably the bolt moving means is a single auxiliary member having a part engaged with the bolt and a part guided for sliding movement of the member in a slot in the lock case.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which:- Figure 1 is an inside schematic view of a lock case of a cylinder mortice lock of the invention. with the deadbolt of the lock extended, Figure 2 is a view as in Figure 1, but with the deadbolt retracted, Figures 3 and 4 are respectively a side view and an underneath view of the deadbolt of the lock, Figures 5 to 7 are respectively a view of one side, an end view and a view of the other side of an auxiliary member of the lock, Figures 8 and 9 are respective schematic views showing details of a cap and case body of the lock case, and Figure 10 is a side view of a detainer of the lock of the invention.

The lock shown in Figures 1 and 2 of the drawings is in the general form of a conventional cylinder mortice lock which comprises a lock casing which is received in use in a hole cut into the thickness of one edge of a door. The lock casing is of generally rectangular form comprising a case body 10 which forms an enclosure for the lock mechanisms, the case body being open at one side for closure by a cap (not shown) in the form of a plate, with fixing screws being received through the cap and into the case body to secure the case body and cap together in the normal manner. At the side of the lock casing which is forward, in use, there is secured a conventional face plate 11 which, in the example illustrated, has a rectangular opening therethrough for reception of a head 12 of a deadbolt 13 of the lock. The face plate also has holes 14 for fixing screws for securing the face plate to the door.

Although as shown in Figures 1 and 2 the lock comprises merely the deadbolt 13, operable, as will be described, by the action of a lock cylinder, the invention is also applicable to locks with further components, for example a latch bolt which can be operated by the lock cylinder, or, more usually, by way of respective handles at opposite sides of the door. As will be evident from the description below, the invention relates to the throw of the deadbolt, and thus has application with various different forms of cylinder locks.

From Figures 1 and 9 it can be seen that the base of the body 10 has various configurated openings therethrough. Firstly there is a conventional opening 15 for reception of a standard lock cylinder 15a, with conventional cam 15b, whilst secondly, above this opening 15 is an arcuate concave opening 16 which is struck about a radius centred on a longitudinal centre line through the opening 15 at a position below the centre of the radius which defines the arcuate upper part of the lock cylinder opening 15. The arcuate opening 16 extends over approximately 90' of arc, being symmetrically arranged relative to said longitudinal centre line of the opening 15. Thirdly, at the left hand side of the opening 15 is a straight, elongated slot 17 which has its longitudinal centre line normal to the longitudinal centre line of the opening 15, and lying just below said centre of the arcuate upper part of the opening 15. For clarity, this slot 17 is not shown in Figures 1 and 2.

Figure 8 shows openings provided in the cap of the lock case, and from this Figure it can be seen that there is a conventional opening 18 for the standard lock cylinder 15a, this being identical with the opening 15, which two openings are aligned when the cap is fitted on the case body so that the standard lock cylinder can be fitted to the lock case, in the normal manner, once the lock, without the lock cylinder, has been received in the mortice in the door edge, the lock cylinder then being secured in position in the normal manner. Generally the lock cylinder would be of double cylinder form. Above the opening 18, and disposed normal to the longitudinal centre line of the opening 18 is an elongated rectangular slot 19 which has square ends in contrast to the slot 17 which has its ends rounded. Moreover the slot 19 is offset to one side (as viewed the right hand side) of the longitudinal centre line of the opening 18. With the cap fitted on the case body, this slot 19 is disposed just above the arcuate opening 16. However for clarity slot 19 is not shown in Figures 1 and 2.

Figures 3 and 4 show the deadbolt 13, the head 12 of which is generally rectangular and has integrally formed at its rear end a bolt lath or stem 20. The upper surface of the lath 20 is formed with a pair of spaced recesses 21/ 22 respectively which are interrupted by a land 23. The lower surface of the bolt lath 20 has a first straight, flat portion 24 continuing from the undersurface of the bolt head 12, but is then arcuately curved upwardly to form a surface 24a which, as shown in Figure 2, substantially matches the curvature of the upper part of the opening 15 for the lock cylinder 1 Sa. This surface 24a extends over approximately 900 of arc, and is then continued as a flat surface 25 parallel to the flat undersurface of the bolt head. As shown in Figure 4, this surface 25 reduces in width along its length by virtue of the side of the deadbolt which is adjacent the base of the body 10 being stepped inwardly to form a recess 26. The surface 25 terminates in a nose part 27 which is formed at a portion of the lath 20 which is of still further reduced width by virtue of a recess 28 immediately adjacent the recess 26 again in the side of the lath which faces the base of the case body 10, in use. At this recess 28, this lower surface of the lath is also cut away upwardly so as, as will be described, to allow the cam 15b of the cylinder lock to move into engagement with the nose part 27, as shown in Figure 2. As can be seen from Figures 3 and 4, both of the recesses 26 and 28 extend normal to the longitudinal extent of the deadbolt and through the whole of its depth.

Finally it can be seen from Figures 3 and 4 that a circular peg 29 extends from the side of the lath which faces the base of the case body 10, in use, this peg being disposed at the corner formed by the junction of the surfaces 24 and 24a. As will be explained, this peg is received in the slot 17 so as to guide movement of the deadbolt. From the opposite side of the lath, at the end thereof remote from the head 12, is a projection 30. As can be seen in Figure 3, this projection is at a level of the land 23 and comprises upper and lower rectangular ears which project normally from the side of the bolt lath which faces the lock casing cap, in use, the lower ear extending somewhat further than the upper ear, as shown in Figure 4. As can also be seen from this Figure, this main part of the side of the lath which faces the cap is recessed inwardly from a lower part thereof which extends from the head 12. However the lower rectangular ear of the projection 30 extends beyond the remainder of this side of the deadbolt so as to be receivable, in use, in the slot 19, again to aid sliding of the deadbolt.

Figures 5 to 7 show an auxiliary member 31 which is acted upon by the cam 15b to effect sliding movement of the deadbolt to retract it into the lock casing. This deadbolt moving member 31 is in one piece, and may for example, be formed of brass, as may the deadbolt 13. The member 31 has a full width part 32 which is formed with a flat cam engagement surface 33 from an upper part of which extends a carrier part 34 which, as shown in Figure 6, is of reduced width as compared to the part 32 and is disposed flush with the side of the part 32 which, as will be explained, faces the base of the case body 10, in use. From the side of the carrier part 34 which is not flush with the part 32, there extends a circular peg 35 which is of a radius such that it can engage in the recess 28 in the bolt lath and slide therealong. From the other side of the carrier part 34, there extends an elongate projection 36, with the centre of the peg 35 lying on the longitudinal centre line of said projection 36. The projection is generally arcuate, with rounded ends, the curvature of the longer sides of the projection generally matching the curvature of the arcuate opening 16, so that, as shown in Figures 1 and 2, this projection can be received in the opening 16 for movement therealong from one end to the other concurrent with extension and retraction of the deadbolt, as will be described.

Finally although not directly related to the present invention, the lock includes a detainer 37 which is pivotally mounted within the lock casing, and spring loaded, so as, in the normal manner, to act upon the deadbolt to hold it in either its fully extended or fully retracted position, the cam 15b engaging a curved undersurface 38 of the detainer to lift it by pivoting to release it from engagement with the deadbolt when the retraction or extension is to take place.

On assembly, the deadbolt is received in the lock casing with its peg 29 received in the slot 17 and the lower ear of the projection 30 being received. in the slot 19 so that the bolt is guided with its head 12 extending and retracting through the opening in the case body and also in the face plate. The member 31 is received in the lock casing with its projection 36 received in the opening 16 and its peg 35 received in the recess 28 in the bolt lath. In this manner the deadbolt and the member 31 are linked for movement together. The lock cylinder 15a is fitted to the lock casing as described, so that its cam 15b is in the position shown in Figures 1 and 2 in the fully extended and full retracted positions respectively of the deadbolt.

Accordingly with the deadbolt fully retracted as shown in Figure 2, the cam 15b is disposed between the nose part 27 of the bolt lath and the engagement surface 33 of the bolt moving member 31. Upon actuation of the lock cylinder by a key in the normal manner, anticlockwise rotation, as viewed in Figure 2, will cause the cam 15b engaged with the nose part 27 to push the deadbolt outwardly from the lock case to its fully extended position, the angular movement of the cam also raising the detainer, as described, in order to free the bolt from its engagement therewith and to allow its extension movement. As this angular rotation of the cam continues, the engagement of the peg 35 in the recess 28 will ensure that the member 31 moves with the deadbolt, to the left as viewed in Figure 2. This movement is possible by way of the projection 36 sliding along the arcuate opening 16, with the peg 35, during this movement, sliding upwardly and then downwardly in the recess 28. Eventually, in the Figure 1 position, with the deadbolt fu 1 ly thrown, the cam 15 disengages from the nose part 27, with the projection 36 being at the left hand end of the opening 16 and the circular peg 35 again at the bottom of the recess 28. In this position the detainer will have again 'fallen' so as to hold the deadbolt in this fully extended position.

If the lock cylinder is now actuated in the opposite, i.e. clockwise, direction, the cam 15 will move to the Figure 1 position where it engages the surface 33. Continued angular movement of the cam will thus force the member 31 to retrace the path of movement taken during anticlockwise movement of the cam, with the projection 36 travelling back along the length of the opening 16 to the Figure 2 position. As the member is forced to move to the right, as viewed in the drawings, the engagement of the peg 35 in the recess 28 again ensures that the deadbolt moves with the member 31, so that as this member is moved to the right, the deadbolt is retracted from its Figure 1 position to the position shown in Figure 2 which is reached when the member 31 reaches the position shown in Figure 2 where its projection 36 is at the right hand end of the opening 16.

With this arrangement an increased amount of deadbolt throw is produced, for example 20mm. It will be appreciated from the operation described that movement of the bolt in one direction is effected by direct engagement of the lock cylinder cam with the deadbolt, whilst movement of the deadbolt in the opposite direction is effected by engagement of the cam with the bolt moving means which is linked to the deadbolt. Thus the disadvantages referred to in relation to prior art arrangements are overcome in that there is no build up of tolerances as with the deadbolt being moved directly by the cam during both retraction and extension, and additionally even with smaller lock cases it is possible sufficiently to support the bolt moving member in that it does not both retract and extend the deadbolt but only carries out one of these operations. With the arrangement described and illustrated, the additional throw is possible by virtue of the curved opening 16 which enables the member 31 to be contacted by the cam for longer, so that even with the increased throw of, for example, 20mm, the member 31 can fully return the deadbolt to its retracted position. As shown in Figure 2, even with the small size of lock casing there is sufficient space for the member 31 to be received at the end of its opening 16 without this member engaging any part of the case body 10. If, in contrast, the auxiliary member contacted by the cam for moving the deadbolt moved linearly, it might not be possible to provide increased throw of the bolt with such a small lock case.

It will be appreciated that instead of a single bolt moving member, two or more members could be provided to form bolt moving means. Moreover -lo- in accordance with the invention.. it would be possible to arrange for a bolt moving member, or bolt moving means to effect extension of the deadbolt, with the cam engaging directly on the deadbolt to retract it, i. e. the reverse of the illustrated arrangement.

Claims (12)

1. A lock comprising a lock case, a lock cylinder carried by the lock case, a cam of the lock cylinder, a bolt arranged to extend and retract out of and into the lock case, in use, and bolt moving means, the cam, in use, engaging one of the bolt and the bolt moving means in one direction of rotation of a key of the lock cylinder to extend the boltl and engaging the other of the bolt and the bolt moving means in the other direction of rotation of said key to retract the bolt.

2. A lock as claimed in Claim 1, wherein the bolt moving means has a part engaged with the bolt and a part guided for sliding movement of the bolt moving means in a slot in the lock case.

3. A lock as claimed in Claim 2. wherein said slot in the lock case is arcuate.

4. A lock as claimed in Claim 2 or Claim 3, wherein said part of the bolt moving means engaged with the bolt is a peg slidable in a recess in the bolt.

5. A lock as claimed in Claim 4, wherein said recess extends normal to the direction of bolt retraction and extension.

6. A lock as claimed in Claim 4 or Claim 5, wherein said part of the bolt moving means in said slot in the lock case is a projection extending from a side of the bolt moving means opposite to that from which said peg extends.

7. A lock as claimed in any one of Claims 1 to 6, wherein for engagement by said cam, said bolt moving means has a cam engagement surface and said bolt has a nose part.

8. A lock as claimed in any one of Claims 1 to 7, wherein the cam engages the bolt to extend it, and engages the bolt moving means to retract the bolt.

9. A lock as claimed in any one of Claims 1 to 8, wherein the bolt is guided during its extension and retraction movement.

10. A lock as claimed in Claim 10, wherein said guiding is by way of a projection of said bolt received in a slot in the lock case.

11. A lock as claimed in any one of the preceding claims, wherein the bolt moving means is a single auxiliary member.

12. A lock substantially as hereinbefore described, with reference to, and as shown in the accompanying drawings.