GB2182973A

GB2182973A - Casement fastener

Info

Publication number: GB2182973A
Application number: GB08527990A
Authority: GB
Inventors: Jack Ernest Douglas
Original assignee: HASP INT Ltd
Current assignee: HASP INT Ltd
Priority date: 1985-11-13
Filing date: 1985-11-13
Publication date: 1987-05-28
Also published as: GB8527990D0; GB2182973B

Abstract

A casement fastener comprising a handle 1 pivotally mounted on a base plate 2 and a security locking device to secure the handle 1 in the fastened position. The locking device includes a barrel 8 mounted for limited rotation in the handle 1 by a key 14 received in a key-way 13 and an upstanding pillar 7 on the base plate 2. The pillar 7 is received within the barrel 8 on pivotting the handle 1 to the fastened position with the barrel 8 in the unlocked position whereupon the barrel 8 is rotatable to the locked position to retain the pillar 7 within the barrel 8 to secure the handle 1 in the fastened position. The key 14 is removable from the key-way 13 in the locked position and, to prevent rotation of the barrel 8 to the unlocked position with the key 14 removed, the barrel 8 has a recess 17 opening into the key-way 13 in which a detent 19 resiliently biassed towards the barrel 8 automatically locates on removing the key 14 to retain the barrel 8 in the locked position. The detent 19 is disengaged from the recess 17 to permit rotation of the barrel 8 to the unlocked position on insertion of the key 14 in the key-way 13. <IMAGE>

Description

SPECIFICATION Casement fastener This invention relates to casement fasteners and in particular to casement fasteners incorporating a security device to prevent inadvertent or unauthorised operation.

It is already known to provide casement fasteners of the type comprising a lever handle pivotally mounted on a base plate with a key-operated cylinder lock to secure the handle in the fastened position. However, such locks are expensive and add considerably to the cost of the fastener.

It has therefore been proposed to provide security locking devices comprising a cylindrical member rotatable in the handle for engagement with the base plate to secure the handle in the fastened position. Such devices are commonly operated by inserting a tool into an opening in the cylindrical member and are of simple and inexpensive construction. However, such devices do not prevent inadvertent or unauthorised operation, for example the cyiindrical member may be rotated by finger pressure on the outer end of the member while almost any tool can be inserted into the opening to rotate the cylindrical member.

It is an object of the present invention to provide a casement fastener having a security locking device which mitigates the disadvantages above-described.

According to the present invention, a casement fastener having first and second parts adapted for mounting on respective frame members is provided with a security locking device comprising an element mounted on the first part for rotation by a key for engagement and disengagement with the second part in locked and unlocked positions respectively and, a detent engageable with the element in the locked position to prevent rotation of the element, the detent being disengaged from the element to permit rotation of the element on insertion of the key.

By the instant invention, the element is positively retained in the locked position by the engagement of the detent with the element thereby preventing rotation of the element by finger pressure or by a tool, such as a screwdriver blade, engaging the opening of the key-way. In this way inadvertent or unauthorised operation of the security device is substantially precluded or at least imposes sufficient delay to be a deterrent against unauthorised access.

Preferably the detent is engageable in a recess in the element, said recess extending into the key-way. In this way the key directly engages the detent on insertion to disengage the detent from the element to permit rotation of the element to the unlocked position.

Conveniently, the recess extends from the base or inner end of the key-way and the detent is constructed and arranged so that substantially complete insertion of the key into the key-way is required to disengage the detent. As a result, inadvertent or unauthorised operation of the security device by insertion of a tool partially into the key-way is precluded.

Preferably the key-way and key have complementary formations whereby only the key having formations matching the key-way formations can be inserted into the key-way to disengage the detent and rotate the element to the unlocked position. As a result, operation of the security device by a non-matching key is prevented in a simple and effective manner and at considerably reduced cost as compared with a conventional cylinder lock.

Preferably the detent is resiliently biassed towards the element and engages automatically in the element recess on withdrawal of the key in the locked position. For example, the detent may comprise a leaf or bridge spring of which a part is engageable in the element recess. Alternatively, the detent may comprise a spring loaded plug engageable in the element recess.

Conveniently, the element comprises a barrel having a lateral entry through which a pillar on the second part can pass to be received within the barrel in the unlocked position and an obdurating wall portion which retains the pillar within the barrel in the locked position.

Preferably the barrel is rotatable through about 90" between the locked and unlocked positions. Advantageously the lateral entry is provided by a diametric slot in the lower or inner end face of the barrel and the opposed walls of the slot form the obdurating wall portion.

Preferably the barrel is mounted for limited rotation between the locked and unlocked positions by means of a stop pin engaging a groove in the periphery of the barrel. The groove is part annular and the opposed ends of the groove provide limit stops restricting rotation of the barrel and defining the locked and unlocked positions respectively. In this way, engagement of the detent in the element recess in the locked position is ensured on withdrawing the key.

The stop pin may extend radially with respect to the barrel with one end received in the groove which has an angular extent slightly greater than the extent of rotational movement of the barrel. Alternatively, the stop pin may extend tangentially with respect to the barrel with a centre portion received in the groove which has an angular extent of about twice the extent of angular movement of the barrel.

The first part may comprise a lever handle pivotally mounted on a base plate forming the second part. Alternatively, the first part may comprise a bracket adapted to receive a stay, link or arm forming the second part.

Several embodiments of casement fastener according to the present invention will now be described with reference to the accompanying drawings, wherein: FIGURE 1 is a side view, partly in section, of a first embodiment of casement fastener according to the present invention showing the security device in the locked position and the key withdrawn; FIGURE 2 is a side view similar to Figure 1 with the key inserted; FIGURE 3 is a side view similar to Figure 2 but with the key rotated through 90" showing the security device in the unlocked position; FIGURE 4 is an exploded perspective view of the security device of the fastener shown in Figures 1 to 3; FIGURE 5 is a side view similar to Figure 1 of a second embodiment of casement fastener according to the present invention having an alternative construction of detent;; FIGURE 6 is a side view similar to Figure 1 of a third embodiment of casement fastener according to the present invention having a further alternative construction of detent; and FIGURE 7 is an end view showing a modification to the security device of Figure 4.

Referring first to Figures 1 to 4 of the accompanying drawings, there is shown a casement fastener comprising a first part being a handle 1 mounted on a second part being a base plate 2 for pivotal movement about a pivot pin 3 through which the two parts are secured together. The base plate 2 is provided with countersunk holes 4 by means of which it is mounted on the stile of a sash frame (not shown) by screws (not shown).

The casement fastener, in known manner, is arranged to engage a keeper (not shown) mounted on the fixed frame (not shown), the keeper having a lug or nose that is arranged to be received within an opening 5 formed between the base plate 2 and handle 1 to hold the sash closed, or to be received within an opening 6 formed in the handle 1 to hold the sash in a ventilating position.

Mounted in the base plate 2 there is a pillar 7 which is upstanding from the base plate 2.

The pillar 7 may comprise a roll pin which is a force fit in a suitable drilling in the base plate 2 so that it can be fitted simply and when desired.

Mounted in the handle 1 there is. a barrel 8 rotatable in a complementary bore 9 in the handle 1 extending parallel to and offset from the axis of pivotal movement of the handle 1.

Intermediate the ends of the barrel 8 there is formed a part annular groove 10 extending half-way around the periphery of the barrel 8.

Through a drilling in the handle extending tangentially to the barrel 8 and penetrating the wall of the bore 9, there is held another roll pin 11 which seats in the groove 10 in the barrel 8 to secure the barrel 8 in the handle 1 against axial displacement. The opposed ends of the groove 10 in the barrel 8 provide limit stops engageable by the roll pin 11 to define locked and unlocked positions respectively obtained by rotating the barrel through 90".

The barrel 8 has a cylindrical body and and enlarged annular base in which is formed in the end face a diametric slot 12 providing a lateral entry opening to the inside of the barrel 8 through which the pillar 7 can pass in the unlocked position of the barrel 8 shown in Figure 3 to permit pivotal movement of the handle 1.

Formed in the barrel 8 is a longitudinally extending key-way 13 opening to the outer end of the barrel 8 for reception of a key 14 which can be turned to rotate the barrel 8 between the unlocked position and the locked position shown in Figures 1 and 2 in which the opposed sides of the slot 12 form an obdurating wall portion 25 to retain the pillar 7 within the barrel 8 and prevent pivotal movement of the handle 1.

The key-way 13 and key 14 are formed with complementary formations 15 and 16 respectively whereby only a key having formations matching the key-way formations can be fully inserted into the key-way. The key-way 13 extends to the periphery of the barrel 8 and, on insertion of the key 14 the planar outer edge of the key 14 lies flush with the periphery of the barrel 8. Extending from the base of the key-way 13, the barrel 8 is cutaway to form a longitudinally extending rectangular recess 1 7 in the periphery of the barrel 8 which terminates short of the outer end face of the barrel 8.

Formed in the bore 9 is a longitudinally extending rectangular channel 18 terminating short of the outer surface of the handle 1 in which a detent comprising leaf spring 19 is mounted and retained by the enlarged base of the barrel 8. The leaf spring 19 has a first limb 20 seated on the base of the channel 18 and a second, shorter spring limb 21 which faces the barrel 8 and is inclined relative to the first limb 20.

In the unlocked position of the barrel 8 shown in Figure 3, the second limb 21 abuts the periphery of the barrel 8 and is compressed into the channel 18 to permit rotation of the barrel 8 to the locked position shown in Figure 2 in which the second limb 21 is compressed into the channel 18 by the flat outer edge of the key 14.

On removing the key 14 in the locked position, the second limb 21 is released and by the inherent spring resilience expands to engage in the recess 1 7 in the barrel 8 as shown in Figure 1 thereby preventing rotation of the barrel 8 from the locked position.

The second limb 21 is compressed and returned into the channel 16 to permit rotation of the barrel 8 from the locked position on insertion of the key 14, this being facilitated by the inclination of the second limb 21 and the provision of an inclined guide face 22 at the free end of the key 14.

As will now be appreciated the leaf spring 19 provides a detent which automatically engages the barrel 8 on rotation of the barrel 8 to the locked position and withdrawal of the key 14 to prevent rotation of the barrel 8 by finger pressure on the outer end face of the barrel 8 or by a tool, such as a screwdriver blade, inserted into the opening of the keyway 13. Furthermore, the free end of the second limb 21 is received in the inner end of the recess 17 thereby requiring substantially complete insertion of the key 14 to remove the second limb 21 completely from the recess 17 and permit rotation of the barrel 8 from the locked position.Additionally, the provision of complemetary formations 15,16 on the key-way 13 and key 14 ensures that only a key having matching formations can be fully inserted thereby providing added security by enabling each device to have unique complementary formations so that different fasteners cannot be operated by the same key.

Figures 5 and 6 show two further embodiments of casement fastener having alternative constructions of detent. Where appropriate like reference numerals are used to indicate parts corresponding to those of the embodiment of Figures 1 to 4.

In Figure 5 the leaf spring 19 of the first embodiment is replaced by a bridge spring 30 consisting of a single limb having a curved centre spring portion 31 for engagement in the recess 17.

In Figure 6 the leaf spring 19 of the first embodiment is replaced by a plug 40 slidably mounted in a transverse hole 41 in the bore 9 and biassed by a spring 42 towards the barrel 8 for engagement in the recess 17.

The bridge spring 30 and spring loaded plug 40 operate in similar fashion to the leaf spring 19, i.e. engaging automatically in the recess 17 on withdrawal of the key 14 to positively retain the barrel 8 in the locked position preventing pivotal movement of the handle 1 and being returned to the channel 18 or hole 41 on insertion of the key 14 to permit rotation of the barrel 8 to the unlocked position permitting pivotal movement of the handle 1.

Each of the detents above-described is also operable to frictionally retain the barrel 8 in the unlocked position by the engagement with the periphery of the barrel 8.

Figure 7 shows a modification to the security locking device of Figure 4. Where appropriate like reference numerals are used to indicate parts corresponding to those of Figure 4.

In this modification, the part annular groove 10' in the periphery of the barrel 8 extends just over 90" around the barrel 8 and the tangential roll pin 11 is replaced by a radial roll pin 11' the inner end of which is received in the groove 10' to limit rotation of the barrel 8 by engagement with the opposed ends of the groove 10'. The provision of the radial roll pin 11' has the advantage that the arcuate extent of the groove 10' is considerably reduced as compared with the groove 10 required for the tangential roll pin 11 so that less material has to be removed from the barrel thereby reducing to the minimum any potential weakening of the barrel in this region.

The invention is not limited to the embodiments of casement fastener above-described, for example the casement fastener may comprise a bracket on which the barrel is rotatably mounted with the bracket adapted to receive a sliding or pivotted stay, link or arm having one or more pillars mounted thereon for engagement and disengagement with the barrel.

The provision of complementary formations on the key-way and key enables each fastener to have a unique combination for added security as above-described. However, for certain situations such as in the home where several fasteners may be fitted to different windows throughout the house, each fastener may have a barrel with the same key-way formations so that the user only requires a single key to operate each security device.

Finally, the inventive principle of a detent which engages the rotatable barrel automatically on withdrawal of the key in the locked position and is disengaged on insertion of the key may be applied to other constructions of security device employing an element which is rotatable between locked and unlocked positions.

Claims

1. A casement fastener having first and second parts adapted for mounting on respective frame members and a security locking device comprising an element mounted on the first part for rotation by a key for engagement and disengagement with the second part in locked and unlocked positions respectively and, a detent engageable with the element in the locked position to prevent rotation of the element, the detent being disengaged from the element to permit rotation of the element on insertion of the key.

2. A fastener according to Claim 1 wherein the detent is engageable in a recess in the element, said recess extending into a key-way for the key.

3. A fastener according to Claim 2 wherein the recess extends from the base or inner end of the key-way.

4. A fastener according to Claim 3 wherein the detent is constructed and arranged so that substantially complete insertion of the key into the key-way is required to disengage the detent from the recess.

5. A fastener according to any one of Claims 2 to 4 wherein the key-way and key have complementary formations.

6. A fastener according to any of Claims 2 to 5 wherein the detent is resiliently biassed towards the element.

7. A fastener according to Claim 6 wherein the detent comprises a member having an integral resilient portion for engagement and disengagement in the element recess.

8. A fastener according to Claim 7 wherein the member comprises a leaf or bridge spring.

9. A fastener according to Claim 6, wherein the detent comprises a member resiliently biassed by a spring for engagement and disengagement in the element recess.

10. A fastener according to any one of the preceding Claims wherein the element comprises a barrel having a lateral entry through which a pillar on the second part can pass to be received within the barrel in the unlocked position and an obdurating wall portion to retain the pillar within the barrel in the locked position.

11. A fastener according to Claim 10 wherein the barrel is mounted for limited rotation between the locked and unlocked positions by means of a stop pin engaging a groove in the periphery of the barrel.

12. A fastener according to Claim 11 wherein the opposed ends of the groove provide limit stops restricting rotation of the barrel and defining the locked and unlocked positions respectively.

13. A fastener according to Claim 12 wherein the stop pin extends radially with respect to the barrel.

14. A fastener according to Claim 12 wherein the stop pin extends tangentiaily with respect to the barrel.

15. A fastener according to any one of Claims 11 to 14 wherein the barrel is rotatable through about 90" between the locked and unlocked positions.

16. A fastener according to any one of Claims 10 to 15 wherein the lateral entry is provided by a diametric slot in the lower or inner end face of the barrel and the opposed walls of the slot form the obdurating wall portion.

17. A fastener according to any one of the preceding Claims wherein the first part comprises a lever handle pivotally mounted on a base plate forming the second part.

18. A casement fastener substantially as hereinbefore described with reference to Figures 1 to 4 of the accompanying drawings.

19. A casement fastener substantially as hereinbefore described with reference to Figures 1 to 4 of the accompanying drawings as modified by any of Figures 5, 6 and 7 of the accompanying drawings.