GB2205605A - Lockable window or door fittings - Google Patents

Abstract

A lockable window or door fastener includes a key-operated barrel lock 24 housed within a cylindrical bore portion 32b in a lever-type operating handle 10 pivotally mounted upon a base plate 14. The barrel lock 24 controls and actuates a detent locking element 26 having a detent portion 28 adapted to be moved into and out of engagement with a locking recess 30 in the base plate 14. The detent locking element 26 is slidably accommodated in a cylindrical bore portion 32a disposed parallel side-by-side intercommunicating relationship with the bore portion 32b and with a follower portion 38, integrally connected in laterally offset relationship to the detent portion 28, slidably accommodated within a lower part of the bore portion 32b beneath the barrel lock 24. The detent locking element 26 is upwardly biassed towards a retracted position by a spring. The bottom end face 50 of the barrel lock 24 and the opposed top face 52 of the follower portion 38 form cooperating planar cam faces whereby rotation of the barrel lock 24 controls the position of the spring biassed locking element 26 within the cavity 32 and hence the extension and retraction of the detent portion 28. The arrangement is such that any lateral force on the detent portion 20 cannot be transmitted back to the barrel lock 24 and the locking mechanism can withstand considerable abusive forces without damage. <IMAGE>

Description

LOCKABLE WINDOW OR DOOR FITTINGS OR ASSEMBLIES This invention relates to window or door fittings or assemblies of the kind that include a pivoting member, for example a lever-type handle, which is provided with releasable locking means whereby it can selectively be locked to a base member when in a predetermined relative position so that pivotal movement relative to the base member is then prevented. The invention is thus especially applicable to window and door fasteners, for example window casement fasteners, and to window operating levers or even stay assemblies wherein a handle or lever, which may be pivotally mounted on a base plate fixed to a frame part, is provided with locking means for preventing unauthorised operation and for improving security against burglars.

In this respect it is already well known to incorporate in a lever-type handle part of a window fastener a key-operated locking mechanism arranged to control a detent locking element which can be moved into or out of engagement with a locking recess in a base member, as disclosed for example in GB 2 147 046A, GB 2 040 344A and GB 2 105 774A, GB 2 179 695A, GB 1 580 094, GB 2 148 383A and GB 2 092 658A. Also, it is known to provide a lever-type handle part of window fasteners with other forms of locking means for the same purpose, for example a manually adjustable grub screw as disclosed for instance in GB 2 064 639A and GB 2 150 203A, but generally these give a lower degree of security than the key-operated locking mechanisms.

Lockable window or door fittings of the kind in question, however, are liable to be subjected to excessive force and abuse, especially if attempts are made forcibly to overcome the locking restraint, but many of the prior art designs have been found to be lacking in strength and resistance to abusive treatment. With devices such as window fasteners, for example, having lever-type handles designed to be gripped and manipulated by hand, any detent locking means often has to be positioned adjacent or in close proximity to the pivot, i.e. in a position where the maximum abusive forces are likely to be applied when the handle is operated as a lever, so that there is an inherent need to design such detent locking means with a high degree of mechanical strength to resist such abusive forces.On the other hand, this objective frequently conflicts with constraints imposed by other requirements in the design of the fitting. Thus, for windows it is generally necessary to provide a maximum glazed area with a minimum width of the sash and surrounding window frame and this immediately imposes practical limits for the maximum width of base plates and lever handles which, in turn, imposes limits on the size or dimensions of cavities in such handles and of locking mechanisms which may be contained in such cavities. Within such constraints, it follows therefore that any detent locking element should be as large as possible.Nevertheless, in some prior art designs, as for example in the lever handle window fastenings of GB 2 147 046A and GB 2 105 774A, a detent locking element is provided which is in the form of a locking pin having a relatively small diameter considerably less than the width of the handle and base plate and less than the diameter of a cylinder lock provided for operating such detent element so that the mechanical strength of the arrangement is particularly limited.

Again, it is most undesirable that any stress to which a detent locking element may be subjected should be transmitted back to the actuating mechanism provided.

For example, in the arrangement of GB 2 147 046A, although the locking pin is coaxially aligned with a keyoperated cylindrical lock body that constitutes a rotatable actuating member, if the locking pin should become bent a turning moment could be generated under the continued application of abusive forces and this turning moment may tend to rotate the actuating member and release the locking pin. Or, in other arrangements in which a detent locking element is actuated by a keyoperated cylinder or barrel lock, if any abusive forces are transmitted back to the latter, as may well occur in some designs where the detent locking element is offset from the centre line of the lock, there may be a tendency for the cylinder or barrel lock to be turned and damage may be caused, especially to pin or disk tumblers of the lock.

In some of the prior art designs a lever handle is provided with a cylinder or barrel lock which moves axially to actuate a detent locking element and, as disclosed in GB 2 105 744A for example, the axial movement is produced by engagement of a projecting portion with a helical groove or screw thread. However, space must also be provided for accommodating the usual pin tumblers or disc tumblers associated with the cylinder or barrel lock and, taking into account the dimensional constraints on the size of the handle part, only limited space is generally available for providing any such helical groove or screw thread which must accordingly be limited in length. This therefore limits the extent of possible axial movement and the distance through which the detent locking element can be moved into and out of engagement with a locking recess in the base plate.In consequence, it may not be possible to provide for a fully adequate depth of engagement in the locked position to ensure a high degree of security.

Also, with this type of design the need to provide a helical groove or thread within the lock-receiving cavity of the handle part tends to give manufacturing problems leading to costly production. In an attempt to avoid a need to form a helical groove or thread directly in the material of the handle part, it has been proposed in GB 2 179 695A to utilise two separate bushes fitted in a plain cylindrical bore in order to define the groove or thread, but this also is not entirely satisfactory since these bushes represent extra components and increase the cost of assembly and, moreover, a larger cavity to accommodate them is required in the handle part which could tend to weaken the mechanical strength of the latter at a critical point. Problems may also arise with these designs in respect of wear of the projecting portionor follower which engages the helical groove or thread.

A principal object of the present invention is accordingly to provide an improved form of lockable window or door fitting which can overcome at least some of the problems or disadvantages associated with the prior art designs and which can enable a high degree of security to be achieved.

According to the invention, in a window or door fitting or assembly having an angularly movable pivoting operating member which can selectively be locked in a predetermined relative position to a relatively fixed base member by releasable locking means having a rotatable actuating member arranged to control a detent locking element of which a detent portion is engageable with a locking recess in the base member, the detent locking element and said rotatable actuating member are separate parts operatively connected through interengaging cam means and the detent portion of the detent locking element is movable into and out of engagement with said locking recess along an axis which is parallel to but offset from the axis of the rotatable actuating member.

In preferred embodiments the rotatable actuating member comprises a key-operated barrel lock which is housed within a cylindrical bore portion of a cavity in the pivoting operating member and which is arranged so that its axis, co-axial with said bore portion, extends in parallel relation ship with the pivotal axis of the operating member. Also, the detent locking element is slidably but non-rotatably mounted within the operating member so that the detent portion thereof moves along a bore portion extending parallel to but offset from the bore portion that houses the key-operated barrel lock, and said detent portion is integrally connected with a follower portion extending laterally therefrom for cooperation, through said interengaging cam means, with the barrel lock.

The detent locking element will generally be biassed by a spring so as to be urged into a retracted position within the operating member and the cam means advantageously comprises a cam surface on the barrel lock which engages and co-operates with a surface of the follower portion of the detent locking element so that when the barrel lock is turned in one direction to a locked position the detent locking element is moved axially against its spring bias into an extended position, and when the barrel lock is turned in the opposite direction to an unlocked position the detent locking element is permitted to move back under the action of the spring bias into its retracted position.

Preferably, the cam surface on the barrel lock is provided by an inclined planar bottom end face of the barrel lock body which extends obliquely, at an angle of about 30 for example, to a plane perpendicular to the axis of the barrel lock and which is opposed to a similarly inclined planar top face of the follower portion of the detent locking element disposed in axial alignment therewith.

Generally, the pivoting operating member will be of elongate form such as a pivotally mounted lever-type handle which may be formed as a metal die casting, preferably with a single cavity comprising a pair of parallel side-by-side intercommunicating cylindrical bore portions opening on the underside of the handle, one of these bore portions being that which houses the barrel lock and also the follower portion of the detent locking element and the other bore portion accommodating the detent portion of the detent locking element. The components can then be readily assembled from beneath and can be retained within such cavity by a cover member closing the underside of the cavity except for an aperture through which the detent portion can project for engaging in the locking recess of the base plate.

Additional features and advantages derivable from the invention will become apparent from the following particular description.

By way of example a lockable window fastener representing one embodiment of the invention will now be further described with reference to the accompanying drawings.

In said drawings: FIGURE 1 is a perspective view of the fastener which is shown in a closed and locked condition with certain internal components of locking means incorporated therein being indicated in broken lines; FIGURE 2 is a longitudinal section on line II - II of FIGURE 1; FIGURE 3 is an exploded view of the fastener with the locking means components thereof shown in the same relative positions as they occupy in FIGURE 1; FIGURE 4 is a view similar to FIGURE 1 but showing the fastener in an unlocked and partially open condition; FIGURES 5 and 6 are views similar to FIGURES 2 and 3 respectively but in which the fastener is shown in an unlocked condition; and FIGURE 7 is a fragmentary section taken along line VII VII of FIGURE 2.

Referring to the drawings, the fastener of this embodiment comprises a lever-type handle 10 having an enlarged head portion 10a mounted, by means of an integral spigot portion 12, for pivotal movement upon a base plate 14 which is adapted to be rigidly fixed to the sash frame of an openable window (not shown) by screws received in screw fixing holes 16a,16b. In this particular example, to secure the handle 10 in place the spigot portion 12 extends through a bearing hole 18 of the base plate 14 and is rivetted over within an enlarged cavity 20 during assembly. The spigot portion 12 thus defines a pivot axis P extending perpendicular to the general plane of the base plate 14 adjacent the extreme end of the head portion 10a of the handle 10.

The head portion 10a of the handle 10 in this particular embodiment is also formed with an integral laterally-projecting latching lug 22 adapted to engage in a conventional manner with a part of the fixed frame of the window surround when the window is shut and when the fastener is set in its closed condition.

For locking the fastener in its closed condition the handle 10 is provided with locking means comprising a key-operated cylindrical barrel lock 24 arranged to control and actuate a detent locking element 26 having a detent portion 28 adapted to be moved into and out of engagement with a locking recess 30 in the base plate 14.

As shown, the detent locking element 26 is housed in a cavity 32 in the head portion 10a of the handle 10, this cavity being formed by a pair of parallel side-byside intercommunicating cylindrical bore portions 32a, 32b, extending parallel to the pivotal axis P. The lefthand bore portion 32a (as seen in FIGURE 2) extends upwardly from the underside for approximately half the depth of the handle head portion 10a whilst the other, right-hand portion 32b extends upwardly through to the outer face 34 of the head portion 10a.

The detent portion 28 of the detent locking element 26 is in the form of a short cylindrical body slidably accommodated within the bore portion 32a of the cavity 32 and its upper section is integrally connected through a neck portion 36 to a laterally offset follower portion 38. This follower portion 38 is also of a basically cylindrical form and is slidably accommodated within the lower part of the bore portion 32b of the cavity 32, whilst the cylindrical barrel lock 24 is accommodated in the upper part of this bore portion 32b.

The follower portion 38 thus lies in axially parallel relationship with the body of the detent portion 28 (as well as with the pivotal axis P) and in co-axial alignment with the barrel lock 24. The detent locking element 26 is thus mounted to move slidably like a piston in order to extend or retract the lower section of the detent portion 28 relative to the underside of the handle head portion 10a, but cannot rotate within the cavity 32.

It is held in place by a cover plate 40 which closes the cavity 32 from underneath except for an aperture 42 to permit passage of the detent portion 28.

The cover plate 40 also provides an abutment for one end of a coil spring 42 which extends upwards into an axial recess 44 in the lower end of the follower portion 38 thereby to bias the detent locking element 26 upwards in cavity 32 to a position in which the detent portion 28 is fully retracted.

The cylindrical barrel lock 24 is of a conventional type associated with a lock mechanism including disc or pin tumblers or other locking elements (not shown) and it can be rotated in the upper part of the bore portion 32b by means of a key 46 which releases the locking mechanism.

The body of the barrel lock 24 is of at least substantially the same diameter as the follower portion 38 of the detent locking element 26 and, as shown, its bottom end face 50 and the opposed top face 52 of the follower portion 38 are both of planar form extending obliquely at a similar angle of about 30&commat; to a plane perpendicular to the axis of the bore portion 32b. The bottom face 50 of the barrel lock 24 thus forms an inclined cam face that co-operates with the similarly inclined top face 52 of the follower portion 38 and thereby controls the position of the detent locking element 26 within the handle cavity 32 upon rotation of the barrel lock.

The barrel lock 24 is retained within the bore portion 32b at the top by an annular flange or rim 56 which reduces the diameter of the bore where it opens through into the outer face 34 of the handle head portion 10a and which defines an internal shoulder 58 that mates with a reduced diameter upper end portion 60 of the body of the barrel lock 24.

The upper part of the bore portion 32b is also formed with whatever recesses are required (not shown) to accommodate the disc or pin tumblers or other elements of the lock mechanism.

It is envisaged that in manufacture the handle 10 will generally be fabricated as a die casting and the whole of the cavity 32 including the recesses referred to above may be formed using a single one piece moulding core without need for separate or moving cores or expensive machining operations. Also, the detent locking element 26 itself is of a unitary form eminently suitable for production by pressure die casting techniques, and if required the detent portion 28 could be cast with a recess adapted to accommodate a hardened steel insert, for example a Bissell pin, for reinforcement purposes.

During assembly, it is of course a simple operation to introduce the cylindrical barrel lock 24 and the detent locking element 26, together with the bias spring 42, through the open bottom of the cavity 32 in the handle head portion 10a and then to fit the cover plate 40 to retain these components in place.

In operation, when the fastener is in its closed and locked condition as shown in FIGURES 1 and 2, the barrel lock 24 is set so that the lowest point of its inclined bottom cam face 50 lies directly above and in contact with the highest point of the inclined top face 52 of the follower portion 38 whereby the detent locking element 26 is forced downwards to the maximum extent, against the action of bias spring 42 which is fully compressed, and the detent portion 28 projects downwards into the locking recess 30 in the base plate 14. This prevents any pivotal movement of the handle 10 and the locking action can only be released by turning the barrel lock 24 in the bore portion 32b with the key 46.

Upon inserting the key 46 and turning the barrel lock 24 through 180 , into the position shown in FIGURES 4 and 5, the fastener is brought into its unlocked condition in which the detent portion 28 is fully retracted out of engagement with the locking recess 30 and the handle is free to pivot on the base plate. As will be clearly seen from the drawings, in this condition the inclined bottom cam face 50 of the barrel lock 24 and the inclined top face 52 of the follower portion are brought into a parallel mating relationship with the lowest point of cam face 50 directly above and in contact with the lowest point of the face 52, thus allowing the detent locking element 26 to move upwards in the cavity 32 under the influence of the bias spring 42 thereby to retract the detent portion 28.

With the fastener in its closed condition it can subsequently be relocked simply by turning the barrel lock 24 back through 1800 into the position of FIGURES 1 and 2.

This construction as described provides a very satisfactory fastener locking arrangement and is characterised by several notable features. Firstly, although the detent portion 28 is offset from the centre line of the barrel lock 24, since these parts are separate and unconnected any force on the detent portion 28 cannot be transmitted back to subject the barrel lock to a turning moment which could damage the locking mechanism of the latter. Secondly, the cam action obtained by the reaction between the opposed inclined faces 50 and 52 when the barrel lock 24 is rotated produces a quick and easy movement for the locking and unlocking operation and, unlike the use of a helical groove and follower, this type of cam mechanism is very compact and is capable of providing a relatively large axial displacement. It can also withstand considerable wear.Thirdly, the construction described is capable of simple manufacturing and assembly methods, and the components are not required to have close manufacturing tolerances, so that production costs can be kept low.

Also, it should be noted that since the thickness or diameter of the detent portion 28 is not dependent on the requirements or size of the barrel lock 24, it can be of the maximum diameter as the width of the handle and of the base plate allow thereby to provide for the greatest strength against abusive force. Furthermore, in that the detent locking element 26 only has a reciprocating movement in the cavity 32 like a piston, and cannot rotate, it can spread the load imposed by force on the lever handle 10 to the most advantageous extent over a substantial surface area.

Although in the embodiment described the detent portion 28 has been shown as being situated between the pivot axis P of the handle and the axis of the cylindrical barrel lock 24, these relative positions may be reversed if desired so that the axis of the barrel lock would then lie between the handle pivot axis P and the detent portion. This would naturally reduce the leverage applied to the detent portion by the handle.

Many other modifications in the particular constructional details are of course also possible within the scope of the invention and, as previously indicated, the invention is applicable not only to window casement fasteners but also to various other types of window or door fasteners or fittings, including espagnolette type fastener operating assemblies and stay assemblies, which include a lockable pivoting member adapted to be locked to a base member or other relatively fixed part.

Claims (11)

1. A window or door fitting or assembly having an angularly movable pivoting operating member which can selectively be locked in a predetermined relative position to a relatively fixed base member by releasable locking means having a rotatable actuating member arranged to control a detent locking element of which a detent portion is engageable with a locking recess in the base member, characterised in that the detent locking element and said rotatable actuating member are separate parts operatively connected through interengaging cam means and the detent portion of the detent locking element is movable into and out of engagement with said locking recess along an axis which is parallel to but offset from the axis of the rotatable actuating member.

2. A window or door fitting or assembly as claimed in Claim 1, wherein the rotatable actuating member comprises a key-operated barrel lock which is housed within a cylindrical bore portion of a cavity in said operating member and which is arranged so that its axis, aligned co-axially with said bore portion, extends in parallel relationship with the pivotal axis of the operating member.

3. A window or door fitting or assembly as claimed in Claim 2, wherein the detent locking element is slidably but non-rotatably mounted within the operating member so that the detent portion thereof moves along a bore portion in said operating member which extends parallel to but offset from the bore portion that houses the keyoperated barrel lock, and wherein said detent locking element includes a follower portion integrally connected to said detent portion and extending laterally therefrom for co-operation with the barrel lock through said interengaging cam means.

4. A window or door fitting or assembly as claimed in Claim 3, wherein the detent locking element is biassed by a spring so as to be urged into a retracted position within the operating member and the cam means comprises a cam surface on the barrel lock which engages and cooperates with a surface of the follower portion of the detent locking element so that when the barrel lock is turned in one direction to a locked position the detent locking element is moved axially against its spring bias into an extended position, and when the barrel lock is turned in the opposite direction to an unlocked position the detent locking element is permitted to move back under the action of the spring bias into its retracted position.

5. A window or door fitting or assembly as claimed in Claim 4, wherein the cam surface on the barrel lock is provided by an inclined planar bottom end face of the barrel lock body which extends obliquely to a plane perpendicular to the axis of the barrel lock and which is opposed to an inclined planar top face of the follower portion of the detent locking element disposed in axial alignment therewith.

6. A window or door fitting or assembly as claimed in Claim 5, wherein the cam surface on the barrel lock extends obliquely at an angle of about 30 to a plane perpendicular to the axis of the barrel lock.

7. A window or door fitting or assembly as claimed in Claim 5 or 6, wherein said inclined planar top face of the follower portion of the detent locking element extends obliquely at an angle of about 30 to a plane perpendicular to the axis of the barrel lock.

8. A window or door fitting or assembly as claimed in any of the preceding claims, wherein the pivoting operating member is of elongate form formed with a single cavity comprising a pair of parallel side-by-side intercommunicating cylindrical bore portions opening on the underside of said operating member, one of these bore portions being that which houses the barrel lock together with the follower portion of the detent locking element and the other bore portion accommodating the detent portion of the detent locking element.

9. A window or door fitting or assembly as claimed in Claim 8 wherein the pivoting operating member is a pivotally mounted lever-type handle formed as a metal die casting.

10. A window or door fitting or assembly as claimed in Claim 8 or 9, wherein the opening of said cavity on the underside of the operating member permits assembly therethrough of the components of the releasable locking means which are housed within said cavity, and said components are retained within said cavity by a cover member which closes the underside of the operating member except for an aperture in said cover member through which the detent portion can project for engaging in the locking recess of the base plate.

11. A lockable window or door fitting or assembly having locking means substantially as herein described and illustrated with reference to the accompanying drawings.