GB2219035A

GB2219035A - Lockable fastener for windows or doors

Info

Publication number: GB2219035A
Application number: GB8912380A
Authority: GB
Inventors: Jack Ernest Douglas; Nigel Philip Shenton
Original assignee: HASP INT Ltd
Current assignee: HASP INT Ltd
Priority date: 1988-05-28
Filing date: 1989-05-30
Publication date: 1989-11-29
Anticipated expiration: 2009-05-30
Also published as: GB2219035B; GB8812786D0; GB8912380D0

Abstract

In a lockable lever handle fastener, the locking element comprises a retractable spring-loaded plunger portion 10, 110 which in an extended locking position projects from the underside of the lever handle for engagement within a locking recess 4 in a base plate 2. The setting of the locking element 110 is controlled by a lock actuating mechanism including a locking cylinder or plug 3, 103. The sides of the base plate 2 are formed with cam faces 115 which engage the outer end of plunger portion 110 if the lever handle is moved from its open position to its closed position with the locking plunger 10, 110 set in its locking mode. Under sufficient pressure, the locking plunger ramps over the cam surface 115 and is thereby forced to retract within the body of the locking cylinder or plug 3, 103 until it is lined up with and is free to enter the locking recess 4 in the base plate 2, thus avoiding any damage caused by fouling the side of the base plate. <IMAGE>

Description

IMPROVEMENTS RELATING TO LOCKABLE FASTENERS FOR FASTENING CLOSURES SUCH AS WINDOWS OR DOORS The present invention relates to lockable fasteners, particularly though not exclusively for fastening movable closures such as windows, doors and the like.

For window and door fasteners having a movable operating member, for example a pivotably mounted lever handle, it is already well known to provide locking means whereby the operating member can selectively be locked in a closed position to prevent unauthorised operation and to improve security. Such locking means commonly includes a movable locking element that is caused to project from the under surface of the lever handle or other operating member and to engage with a locking recess in a base plate in order to carry out the locking operation when the fastener is in the closed position, the movable locking element being retractable from engagement with the locking recess in order to unlock the fastener.

If, however, the movable locking element is placed or set in its projecting or extended locked position whilst the fastener is in the open position it will generally foul an edge of the base plate which presents an obstructing shoulder portion in its path of travel when the operating member is turned towards the closed position, and damage may therefore ensue.

It is therefore an object of the present invention to provide an improved arrangement whereby the possibility of such damage can be avoided in the event that such movable locking element is accidentally set in the locking mode whilst the fastener is in the open position and is inadvertently left in the locked mode when subsequently moving the fastener operating member to the closed position.

More particularly, the present invention provides a lockable fastener, for example for securing a movable closure such as a window or door, in which a manually actuatable operating member, for example a lever handle, that is movable between a fastener open position and a fastener closed position, is provided with locking means operable to lock the operating member in said closed position, said locking means comprising a retractable locking bolt element which is housed in the operating member and which, in an extended locking position, projects therefrom so as in use to engage within a locking recess in an associated fixed base member when.

the operating member is in said closed position, said base member having an external contour that presents a shoulder portion which lies in the path of said locking bolt element in the event that the latter is set in its extended locking position whilst the operating member is moved from said open position to said closed position, characterised in that said locking bolt element whilst set in its extended locking position and said shoulder portion of said base member are relatively movable away from one another against a resilient spring bias and in that said shoulder portion of the base member is formed with a cam face adapted to be engaged by the outer end of said locking bolt element upon moving said operating member from said open position to said closed position whilst the locking bolt element is in its extended locking position, whereby the outer end of said locking bolt element then ramps across said cam face, moving the shoulder portion of the base member and the locking bolt element relatively away from one another until the locking bolt element can reach and enter the locking recess in the fully closed position of the operating member.

Generally, the locking bolt element will be settable in, and releasable from, its extended locking position by manually operable lock actuating mechanism which includes a lock actuating member, such as a key operated or push button actuating member for example, operable to produce axial movement effective to move the locking bolt element into the extended locking position and to retain it in said position against a counter spring biasing force.

In preferred embodiments, it is arranged so that the axial force necessary to overcome the resilient spring bias in order to enable the locking bolt element, when in its extended locking position, to ramp across the cam face of the base member shouldered portion and to enter the locking recess during movement of the fastener operating member to said closed position is greater than the axial force that can reasonably be applied through the lock actuating member by manual operation of the lock actuating mechanism. Thus, the resilient spring bias will generally be provided by a strong spring which will require an axial force of at least 50 Newtons in order to compress it sufficiently to allow the necessary relative movement between the locking bolt element and the base member shouldered portion for the locking bolt element to reach and enter the locking recess.With a push button or key operated lock actuating member for example, a force of this order will usually prevent full retraction of the locking bolt element merely by manual application of thumb pressure or manual turning of a key. This helps to safeguard against the possibility of the lock actuating mechanism being operated before the operating member has reached the fully closed position with the result that there could be a misleading indication that the locking bolt element has been set in its locking position whereas in fact it would not have engaged within the locking recess.

Preferably, the locking bolt element comprises a spring-loaded plunger operatively connected to the lock actuating member of the lock actuating mechanism by a coupling that permits relative axial movement between said plunger and the lock actuating member, and this coupling may include a retaining pin or stud projection on the one part which engages in an axially extending slot in the other part. Alternatively, the relative movement between the shoulder portion of the base member and the locking bolt element, and the resilient spring bias controlling such relative movement, could be provided for by a spring-loaded movably mounted outer part of the base member, this outer part including the shoulder portion and the locking recess for receiving the locking bolt element.

By way ~ of example, two embodiments of lockable fasteners incorporating locking means according to the present invention will -now be described with reference to the accompanying drawings wherein: FIGURE 1 is a general perspective view of a lockable window or door fastener lever handle assembly mounted on a window casement or door leaf; FIGURE 2 is an exploded perspective view of the fastener of FIGURE 1 showing the components relevant to the present invention but omitting those components relevant to the means of assembling the lever handle to the base plate and to the lock actuating mechanism incorporated in the lever handle; FIGURE 3 is an exploded perspective view of some of the components and method of assembly in accordance with one embodiment;; FIGURE 4 is an exploded perspective view of some of the components and method of assembly in accordance with an alternative second embodiment; FIGURE 5 is a cross-section along line A-A in FIGURE 2 showing components of the first of the two embodiments in three different positions during movement in the direction of the arrow towards the closed position of the lever handle; FIGURE 6 is a cross-sectional view similar to FIGURE 5 but relating to the alternative second embodimemt of FIGURE 4.

Referring first to FIGURES 1 and 2 of the accompanying drawings, there is shown a casement fastener comprising a first part, namely a lever handle 1, which is mounted on a second part, namely a base plate 2, for pivotal movement about a pivot through which the two parts are secured together. The fastener incorporates a manually operable lock actuating mechanism in the lever handle, here shown as a push-button type mechanism having a locking cylinder or plug 3 that is shown as in its raised unlocked position. In the base plate 2 is a locking recess 4, flanked by a cam face 5. The locking cylinder or plug 3 terminates in a spring loaded plunger 10, constituting a locking bolt element, which is shown schematically in FIGURE 2. This plunger 10 is retractable under pressure against a strong spring. The plug or cylinder 3 is urged into the unlocked position by a return spring lOA.No other details of the lock actuating mechanism are shown, however, as they are irrelevant to this invention, and the recess 8 for housing the plug or cylinder 3 in the handle 1, and a retaining cap 7, are indicative only of the rest of the complete assembly.

Referring now to FIGURES 3 and 4 of the accompanying drawings, the components of the locking means and methods of assembly thereof in the two embodiments, which differ in respect of the structural details of the retractable plunger locking bolt elements, will next be described.

In FIGURE 3, the locking cylinder or plug that.

controls the setting of the locking bolt element or plunger is designated by the reference numeral 103. 115 is an axial recess formed in the end of the cylinder or plug 103. 112 is a through hole which opens at diametrically opposite positions across recess 115. 111 is a retaining pin which is a push fit into hole 112.

113 is a biassing spring, shown here as coil or spiral compression spring, having a resistance that requires more force to fully compress, than could normally be applied manually by thumb pressure on the push button actuating member. 110 is the locking bolt element or plunger, shown here as a headed element of such configuration as will give maximum resistance to any laterally acting abusive force when fully entered into the locking recess 4 but such as to assist in generating an axial retraction force when traversing the cam face of the base plate if the lever handle is moved from the open position to the closed position whilst the plunger 110 is in its extended locking position, as shown in FIGURE 5.

114 is an elongated slot in plunger 110 through which the retaining pin 111 is able to pass with clearance enabling the plunger to travel axially, into or out of the recess 115, for a limited distance.

The method of assembly of these components is to enter spring 113 into recess 115, followed by plunger 110 to which sufficient pressure is applied until the end of the slot 114 furthest away from the head of the plunger 110 is in line with the through holes 112, at which position retaining pin 111 is then inserted.

In the embodiment of Figure 4, the part of the locking cylinder or plug at the locking bolt plunger end is designated by the reference numeral 203. 215 is an axially-extending recess formed in that end of the cylinder or plug 203. 216 is a double dog-leg slot which opens into the recess 215. 213 is a spring, again shown as coil or spiral spring having a resistance that requires more force to fully compress than could normally be applied manually by thumb pressure. 210 is the locking bolt plunger, shown here as having an oblique cam face 218 at its head and an integral stud 217 on one side. Stud 217 should be of such a dimension and shape as will permit its entry into the open end of the double dog-leg slot 216, allow its passage along the arcuate portion of slot 216, and thereafter allow its free travel within the closed leg of slot 216.The method of assembly is to enter spring 213 into recess 215 and then present stud 217 on plunger 210 to the open end of 216 and fully compress the spring 213, using mechanical assistance until stud 217 bottoms in that slot. Plunger 210 is then rotated until stud 217 is in line with the enclosed return portion of slot 216 when the mechanical assistance can be removed and assembly is complete. It will be appreciated that in this configuration it is possible to provide a cam face at the head of plunger.

210, as shown at 218, because the retraction and projection movement is in a constrained straight line, ensuring that the posture or orientation of the cam face 218 is always correct for face to face engagement with the cam face of the base plate 2 as shown in FIGURE 6 (see below).

In FIGURES 5 and 6 portions of the plug or cylinder actuating member 3 are shown numbered 103 and 203 respectively and the retractable locking bolt plunger element 10 is numbered as 110 and 210, corresponding to the first and second embodiments hereinabove described with reference to FIGURES 3 and 4. These Figures illustrate the effect if, with the locking bolt elements or plungers extended in their locking position, the lever handle is moved from the fastener open position to the fastener closed position. The outer end of the locking bolt or plunger then moves against the cam face 5 of the shoulder portion of the base plate which is numbered here as 115 and 215 and shown as a cross-section through the base plate 2 along A-A in FIGURE 2.The drawings at the left of FIGURES 5 and 6 show the extended retractable locking bolts or plungers 110 and 210 during movement of the lower handle towards the closed portion, in the direction of the thick arrows and impinging on cam faces 115 and 215. The drawings in the centre of each figure show the retractable plungers forced against their bias springs 113 and 213 as they ride up and ramp over the cam faces, and the drawings on the right of Figures 5 and 6 show the plungers fully extended by the thrust of their bias springs and entered into the locking recesses 4.

It will be appreciated that retraction of the locking bolt or plunger from the locking recess 4 during the unlocking process will be achieved by retracting the whole of the locking plugs or cylinders 103 and 203, upon release operation of associated lock actuating mechanism which may be a locking mechanism such as is described, for example, publications in patent GB2205605A or GB2210096A.

The invention is not limited to the embodiments above described. For example, if desired the head of the locking bolt plunger may be rounded or bullet-nosed or it may have a chamfer around the entire periphery. However, as already explained, it should preferably be spring loaded such that full retraction of the locking bolt or plunger cannot be achieved simply by manually applied pressure to the lock actuating mechanism without the assistance of mechanical advantage. Similarly, subject to the same proviso, in can alternative arrangement the am face portion of the base plate can be spring loaded to allow it to retract against force from a fixed locking bolt or plunger placed inadvertently in its locked mode when the fastener is in its open position.

Claims

1. A lockable fastener, for example for securing a movable closure such as a window or door, in which a manually actuatable operating member, for example a lever handle, that is movable between a fastener open position and a fastener closed position, is provided with locking means operable to lock .the operating member in said closed position, said locking means comprising a retractable locking bolt element which is housed in the operating member and which, in an extended locking position, projects therefrom so as in use to engage within a locking recess in an associated relatively fixed base member when the operating member is in said closed position, said base member having an external contour that presents a shoulder portion which lies in the path of said locking bolt element in the event that the latter is set in its extended locking position whilst the operating member is moved from said open position to said closed position, characterised in that said locking bolt element whilst set in its extended locking position and said shoulder portion of said base member are relatively movable away from one another against a resilient spring.

bias and in that said shoulder portion of the base member is formed with a cam face adapted to be engaged by the outer end of said locking bolt element upon moving said operating member from said open position to said closed position whilst the locking bolt element remains in its extended locking position, whereby the outer end of said locking bolt element then ramps across said cam face, moving the shoulder portion of the base member and the locking bolt element relatively away from one another until the locking bolt element can reach and enter the locking recess in the fully closed position of the operating member.

2. A lockable fastener as claimed in Claim 1 wherein the outer end of the locking bolt element is also formed with a cam face produced by a bevelled or inclined end surface effective to engage and co-operate with the cam face of the shoulder portion of the base member thereby to force the base member shoulder portion and the locking bolt element away from one another in a direction axially of the locking bolt element during movement of the operating member to the fastener closed position whilst the locking bolt element is in its extended locking position.

3. A lockable fastener as claimed in Claim 1 or 2, wherein the locking bolt element is settable in, and releasable from, its extended locking position by manually operable lock actuating mechanism including a lock actuating member housed in the fastener operating member.

4. A lockable fastener as claimed in Claim 3 wherein said lock actuating mechanism includes a key-operated or push button actuating member operable to produce axial movement effective to move the locking bolt element into said extended locking position, and to retain it in said position, against a counter spring biassing force.

5. A lockable fastener as claimed in Claim 3 or 4 in which the axial force necessary to overcome the resilient spring bias in order to enable the locking bolt element, when in its extended locking position, to ramp across the cam face of the base member shoulder portion so as to enter the locking recess during movement of the fastener operating member to said closed position is greater than the axial force reasonably applicable to said locking bolt element through said lock actuating member merely by manual operation of the lock actuating mechanism.

6. A lockable fastener as claimed in Claim 5, wherein said axial force necessary to overcome the resilient spring bias is at least 50 Newtons.

7. A lockable fastener as claimed in any of the preceding claims wherein said locking bolt element comprises a spring-loaded plunger.

8. A lockable fastener as claimed in any one of Claims 3 to 6, wherein said locking bolt element comprises a spring-loaded plunger operatively connected to the lock actuating member of the lock actuating mechanism by a coupling that permits relative axial movement between the plunger and said lock actuating member.

9. A lockable fastener as claimed in Claim 8 wherein the coupling includes a retaining pin or stud projection on the one part which engages in axially extending slot in the other part.

10. A lockable fastener as claimed in any of Claims 1 to 6 wherein the locking recess is provided in an outer part of said base member which includes said shoulder portion, said outer part being spring loaded and movably mounted in order to permit the movement relative to the locking bolt element necessary to enable the locking bolt element, whilst in its extended locking position, to ramp over said cam face the shoulder portion and enter the locking recess during movement of the fastener operating member to said closed position.

11. A lockable fastener substantially as herein described and illustrated with reference to Figures 1, 2, 3 and 5 or Figures 1, 2, 4 and 6 of the accompanying drawings.

12. A casement window or door fitted with a lockable fastener as claimed in any one of the preceding claims.