AU700951B2 - Improvements in sliding bolt locks - Google Patents

Description

1 IMPROVEMENTS IN SLIDING BOLT LOCKS.

This invention relates to sliding bolt locks of the type used commonly on security doors comprised of a rectangular frame made from aluminium extrusions with an infill of expanded metal mesh.

Locks for the above purpose desirably have several principal characteristics including, an ability to be used in right hand or left hand :opening doors, 0 (ii) a sliding tongue which normally has a short bolt projection condition so that only a small force acting on the closing door will cause the bolt to retract as the nose of the bolt engages the striker plate on a door jamb, this facilitates the fitment and operation 0. of an automatic door closer to the door, a (iii) an automatic change to a long bolt projection *aaa condition when the tongue is aligned with the aperture in the striker plate on a door jamb, (iv) an automatic return of the bolt to its short bolt projection condition on retraction of the bolt back into the lock body by a lock operating handle, Other characteristics include, provision of deadlock means to deadlock the bolt but only when in the long bolt projection condition, (vi) multiple means to both activate and deactivate the deadlock means, including a manual means operational from what would be the inside of the door and key operated means operable from both sides of the 2 door and which will over-ride the manual means, (vii) a latch means to retain the deadlock means in its operative position to thereby prevent unauthorised release of the deadlock means.

The above features in various combinations are to be found in several known locks. However the mechanisms of the known locks (many of which are patented) reveals the known locks rely on reasonably complex interactions between numerous lock components in order to provide oi o 10 the desired characteristics. The present applicant has set out to provide a lock which has fewer and simpler components than is the case with the known locks but which provide at least the principal characteristics referred to above.

Broadly the present invention can be said to provide a door lock including a housing for mounting to a door, an aperture in a front wall of the housing, a lock bolt with an outer end, said lock bolt is slidably mounted in the housing and aligned with said aperture and movable between an extended condition and a retracted condition where said lock bolt is at least substantially wholly retracted into said housing, latching means to releasably retain said lock bolt in a condition intermediate its extended and retracted conditions, first biassing means within the housing to bias said lock bolt away from its retracted condition, a latch bolt slidably mounted in said housing and aligned with said aperture, the latch bolt has a path 3 of travel convergent with the path of travel of the lock bolt in a direction away from said front wall, second biassing means within the housing to bias said latch bolt to an operative position in which a leading end of said latch bolt extends beyond said housing front wall to substantially the same extent as the outer end of said lock bolt when in said intermediate condition, said latching means comprising a contact face on said lock bolt which bears on a latch face of 10 said latch bolt when said lock bolt is in its intermediate condition thereby preventing travel of said lock bolt from said intermediate to said extended condition, said latch face having an angular relationship to the path of travel of said lock bolt such that force exerted on the latch bolt by engagement of said contact face with said latch face will not result in retracting movement of said latch bolt, the arrangement being such that with the lock bolt latched in its intermediate condition a force applied to the leading end of the latch bolt to move it divergently with respect to said lock bolt into the housing will disengage said latching means contact and latch faces to permit movement of said lock bolt between its extended and retracted conditions.

A presently preferred embodiment of the invention will now be described with reference to the accompanying drawings in which: Fig.l is an elevation of a lock according to the 4 invention with a cover plate for the lock housing removed to enable the lock mechanism to be seen with the lock bolt in a latched intermediate condition, Fig.2 is a view similar to Fig.l showing the lock bolt in the retracted condition.

Fig.3 is a view similar to fig.l showing the lock bolt in the extended condition, Fig.4 is a view similar to Fig.l showing the lock bolt restrained to a limited linear movement and at the 0 retracted end of limited linear movement, o is a view similar to Fig.4 showing the lock bolt at the extended end of the limited linear movement, Fig.6 is a view similar to Fig.3 showing the lock bolt deadlocked in the extended condition, Fig.7 is a view similar to Fig. l showing the position of a manually operated snib means to provide for extended condition lock bolt retention requiring key actuation to permit lock bolt retraction, Fig.8 is a view similar to Fig.7 showing the lock bolt in a retracted condition prior to adopting the retained extended condition, Fig.9 is a view similar to Fig.8 showing the lock bolt after achieving the retained extended condition, and is a view similar to Fig.7 to illustrate the key actuation necessary to allow lock bolt retraction, In Fig. l there is shown a lock casing 1 having a mounting plate 2 and a body 3. The body 3 is defined by walls 4,5,6 upstanding from a panel 7 such that the 5 walls 4,5,6 and the mounting plate 2 enclose a cavity in which the lock working parts are housed. There are other lugs and walls upstanding from the panel 7 of a shape and size and for purposes as are hereinafter described.

The principal operating member of the lock is the lock bolt 8 which is a substantially rectangular solid member with a nose 9 which is rounded or angled to facilitate the use of the lock in a left or right hand opening door. The bolt 8 is slidable between rails and 11 upstanding from the panel 7. The bolt 8 is biassed to an extended condition by a spring 12. The limit of maximum extension of the bolt 8 is governed by engagement of a lug 13 on the bolt 8 with a stop shoulder 14 forming part of the lock body.

e latch bolt 15, also with a rounded or angled nose, co-operates with the bolt 8 to latch it in the short extension condition as shown in Fig.l The bolt is slidably supported between surfaces on members 16 and 17 and is biassed to an extended condition by a spring 18 with its maximum extension governed by engagement between a lug 19 on the bolt 15 with a shoulder 20. The intermediate condition of the bolt 8 as shown in Fig.l results from wedging engagement between the angled contact face 55 of the bolt 8 against a latch face of the bolt 15, the reaction forces from the wedging action are taken on the rail 11 (exerted through the bolt 8) and on the surface of the 6 member 16 (exerted through the bolt 15). The forces applied to the latch bolt through the engagement of the contact and latch faces not being such as to cause retraction of the latch bolt.

It follows that when the lock is mounted in a door and the door closes the outer ends of the lock and latch bolts will engage the striker plate 21. The two bolts will retract to the positions shown in Fig.2 and when the bolt 8 is aligned with the striker plate .0 opening 22 the bolt 8 will be free to move to its fully extended condition as shown in Fig.3, with the bolt held out of its latching relationship with the bolt 8 by its continued engagement with the striker plate 21.

The mechanical movement of the bolt 8 by a handle is achieved by a driving engagement between a handle S. U not shown) and a square shaft 23 in a hub 24 of a control arm 25. The bearing support for the hub is a hole in the panel 7 and an aligned hole in the cover plate which will normally cover and support the components within the lock body 3.

The control arm 25 operates in a recess 26 in the face of the bolt 8. It can be seen from Fig.l that the arm 25 has a rest position, from Fig.2 that the rest position is not disturbed by the movement of the bolt 8 by the striker plate, and from Fig.3 that there is a working relationship established between the arm and the bolt 8 when the bolt 8 is in the fully extended condition and it follows that if the shaft 23 is turned 7 the bolt 8 will be withdrawn from the catch plate opening 22 and the door can be swung open.

The bolt 8 also has a second face recess 27 which with the face 28 of the recess 25 are adapted for co-operating with a deadlocking bar 29 slidably mounted and supported by the lock front plate 2 and faces of the ribs 30,31 and 32 upstanding from the panel 7.

Movement of the bar 29 can be by a key operated lock 33 having an arm 34 adapted to co-operate with recess 0 defining arms 35 and 36 on the bar 29. By moving the arm 34 arcuately the bar 29 is moved longitudinally.

From Fig.l it is clear that if the key is turned the end 37 of the bar 29 will not enter the recess 27 o or the recess 28. Thus when the door is in an open position the deadlock cannot be engaged with the bolt As shown in Fig.4 when the Fig.2 condition exists ego• the bar end 37 can be entered into the recess 27 and Fig.5 shows the resulting modified version of the Fig.3 (bolt fully extended) unlatched condition.

The purpose of this is so that when a door is closed with the bolt 8 engaged in the striker plate opening 22 to a small extent, in fact so that the tapered nose of the bolt 8 is bearing against the edge of the striker plate opening 22, the engagement will be sufficient to hold the door closed against wind and like light forces. However, the householder by leaning against the door or pulling the door by the handle can cause the bolt 8 to retract and the door to 8 open. This facility has advantages where the door needs to be held closed but be readily opened by a person merely by leaning against it.

Fig.6 shows the normal deadlocking arrangement where the bolt 8 is in the striker plate opening 22 and the key lock 33 is used to move the bar 29 so that it will enter the recess 26 and lodge behind the face 28 thereby preventing unauthorised retraction of the bolt 8. In this condition it will be seen that the bar 29 **9R 10 has been moved laterally by the spring loaded ball 38 in the bar 29 as the end 39 of the bar 29 clears the top 40 of the rib 32. The lateral movement is limited by engagement of the bar 29 with the rib 31, there ooee being initially sufficient clearance (indicated 51) therebetween to allow limited lateral movement of the bar 29. This relocation of the end 39 of the bar 29 9*99 will prevent any unauthorised external movement of the bar 29 and makes the operation of the lock by the key essential in order to release the deadlock bar 29 from the bolt 8. As will be seen the bar end 39 is clear of the rib top 40 and does not rely on any direct engagement therebetween for the operation of this security feature. On operation of the key lock the associated arm 34 will enter the recess bounded by and 36 and will as part of its movement engage the bottom 44 of the recess thereby moving the bar end 39 back to alignment with the face inner face of the rib 32 so that as the bar 29 is moved down the relationship 9 as shown in Fig.l will be re-established.

The ball 38 is adapted to engage in dimples 41,42,43 in the inner face of plate 2 to releasably retain the bar 29 for the various operating functions in needs to perform.

The hub 24 has a lug 45 which co-operates with a snib which will substitute for many of the operations performed by the key lock 33. The snib comprises a spindle 46 supported in holes in the panel 7 and the lock body cover when fitted to the spindle 46 to be part rotated. The spindle 46 has a first lug 47 and a second lug 48. The spindle 46 has an extension through the lock and the door to a handle operable from the inside of the door. If the spindle 46 is rotated to the Fig.7 position the arm 25 can execute a slight S. S movement (due to the clearance 49 between the lugs and 48) and this allows the door to be slammed shut and :the lock bolt to assume the Fig.3 extended condition.

Fig.8 shown the clearance 49 eliminated as the bolt 8 moves slightly to pass the catch plate. Fig.9 shows the bolt fully extended with the snib operated. With this condition prevailing it is not possible to turn the shaft 23 more than small amount the eliminate the clearance 49 and this is not sufficient to withdraw the bolt 8 from the extended condition shown in Fig. 9.

The snib can be manually released by rotating the spindle 46. Where the door is snibbed and someone wishes to enter from outside and has a key, the 10 operation of the key lock 33 to move the bar 29 first to a deadlock condition and then to an undeadlock condition will release the snib and allow the handle to be rotated to withdraw the bolt 8. This can be seen from Fig. 10 where it is clear that if the bar 29 is moved by the key lock 33 the lug 50 on the bar 29 will engage the spindle lug 47 and turn the spindle to its rest position as shown in Fig.l. By then reversing *e the key rotation the bar 29 is moved to the Fig.l 10 condition and the handle can operate the bolt 8.

The foregoing description is of a preferred embodiment of the invention and it is to be understood that changes can be made to various components described without departing form the inventive concepts herein disclosed.

0 *g* 11 The claims defining the invention are as follows: i. A door lock including a housing for mounting to a door, an aperture in a front wall of the housing, a lock bolt with an outer end, said lock bolt is slidably mounted in the housing and aligned with said aperture and movable between an extended condition and a retracted condition where said lock bolt is at least substantially wholly retracted into said housing, e latching means to releasably retain said lock bolt in a condition intermediate its extended and retracted conditions, first biassing means within the housing to S.bias said lock bolt away from its retracted condition, a latch bolt slidably mounted in said housing and aligned with said aperture, the latch bolt has a path of travel convergent with the path of travel of the lock bolt in a direction away from said front wall, second biassing means within the housing to bias said latch bolt to an operative position in which a leading end of said latch bolt extends beyond said housing front wall to substantially the same extent as the outer end of said lock bolt when in said intermediate condition, said latching means comprising a contact face on said lock bolt which bears on a latch face of said latch bolt when said lock bolt is in its intermediate condition thereby preventing travel of said lock bolt from said intermediate to said extended condition, said latch face having an angular

Claims (4)

1. 2. A door lock as claimed in claim 1 wherein said S"latch face is a continuation of a side of said latch bolt supported by a bearing face of a track in said housing and said contact face is a chamfer between the OeeO outer end of said lock bolt and an upper edge of said S. :lock bolt juxtaposed said latch bolt.
2. 3. A door lock as claimed in claim 1 or claim 2 including means to limit the maximum projection of both the lock and latch bolts beyond said housing.
3. 4. A door lock as claimed in any one of the claims 1 to 3 having a deadlock means for said lock bolt, said deadlock means including a bar slidably mounted in the housing and movable between an inoperative condition where a locking end of said bar is free of said lock 13 bolt and an operative condition where said locking end of said bar is engaged with said lock bolt when said lock bolt is in its extended condition thereby to retain said lock bolt in its extended condition, and a key actuated means mounted in said housing to move said bar between operative and inoperative conditions. A door lock as claimed in claim 4 further including a recess in said lock bolt engagable by the locking end of said bar when said lock bolt is in a condition range limited by its retracted condition and a predetermined projection condition less than its intermediate condition, the arrangement being such that when said 0 latch bolt is inoperative said lock bolt can move freely between its retracted condition and said predetermined projection condition.
4. 6. A door lock substantially as hereinbefore described with reference to the accompanying drawings. Dated this 29th January, 1996 TECENOSEARCH PTY, UNITED 1 ABSTRACT: A door lock having a multiple extension-condition lock bolt and a latch bolt Both bolts are slidably mounted with convergent paths of travel and are biassed to the extended condition. A latching means to releasably hold the lock bolt in an intermediate extension condition. The latching means includes a contact face (55) on the lock bolt which bears on the latch bolt Unlatching is achieved by retraction of the latch bolt (15) by end engagement with a striker plate on a door frame in which a door o fitted with the lock is mounted.