AU785200B2 - Door lock - Google Patents

Description

P/00/011 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION PATENT OF ADDITION Invention title: Door lock The following statement is a full description of this invention, including the best method of performing it known to us: 2235X2 IO.dl\he CA01036008.6 1 Door Lock Field of the invention The following statement is a full description of this invention, including the best method of performing it known to the applicant:- This invention relates to door locks of the kind having a latch bolt that is retractable from a locked position, wherein the latch bolt extends from the door into a recess in the door frame surrounding the door or an opening in a striker plate on that frame, to an unlocked position, wherein the bolt is clear of the recess or opening, by means of an operating mechanism including a manually rotatable operating handle or knob. In particular, the present invention relates to an improvement in or modification of the door lock described in Australian Patent Application No. 2481/97.

More particularly, the invention relates to such locks wherein the latch bolt is flat ended, as distinct from a bolt with an inclined end face and which is thereby adapted to be retracted automatically by sliding contact with a fixed striker plate on the door surround when the door is 15 pushed shut.

Flat ended latch bolts offer greater security, in that latch bolts with inclined ends can be caused to retract by the insertion of a thin, resilient lamina (such as a plastics card) between the bolt and the striker plate.

On the other hand flat ended latch bolts are less convenient in that the operating handle 20 must be used whenever the door is to be latched shut, resulting in a tendency for people to push e the door to but leave it unlatched.

The invention described in Australian patent application no. 24841/97 is particularly but not exclusively applicable to heavy doors, such as fire doors, which require considerable force to be applied by a person seeking to swing the door from one position to another, and which usually are furnished with locks having a plurality of simultaneously operable latch bolts.

Prior known locks of the kind last referred to have comprised a handle that may be manually rotated about a horizontal axis perpendicular to the plane of the door, a multi-throw CA01036008.6 2 crank mechanism rotatable as one with the handle, and two, three or four connecting rods extending from the crank mechanism to the retractable latch bolts at the door edges. The connecting rods have extended generally horizontally and/or vertically to the respective latch bolts, so that the latch bolts have been positioned so as to coincide with vertical and/or horizontal axes extended through the axis of rotation of the handle.

For security reasons it is preferable for the latch bolts to be positioned at or near the midpoints of the respective edges of the door. Thus, it has been proposed to position the handle at or near the middle of the door. That proposal is not desirable in relation to heavy doors because it is preferable for the handle, on which a person pulls or pushes to swing the door, to be remote from the hinge axis, so as to increase the turning moment about the hinge line for a given force applied to the handle.

The handle of heavy doors is frequently located at the conventional position (about midway between the top and bottom of the door, and adjacent the edge remote from the hinge line), and an off-centre position of the latch bolts at the top and/or bottom edge tolerated, even though this renders the door less secure.

"For descriptive convenience the invention is described below as if mounted on a door as it would be when in use. Furthermore, the various edges of the door are referred to as its "hinged edge", being the upright edge adjacent the hinge axis, its "free edge", being its other upright edge opposite the hinged edge, and its "top edge", and "bottom edge", being its upper and lower horizontal edges respectively.

The invention of Australia patent application no 24841/97 consists in a door lock mechanism comprising at least one flat ended latch bolt, biasing means urging said latch bolts into a latched position wherein the bolt projects beyond an edge of the door, an operating mechanism including a rotatable handle whereby the latch bolt may be drawn, against the effect of the biasing means, into an unlatched, retracted position, and detent means automatically engaging the operating mechanism or latch bolt when the latch bolt is in the unlatched position to then hold the bolt in the unlatched position; said detent means including a striker element adapted to contact the door surround as the door moves into its closed position and thereby disengage the detent means to enable the latch bolt to move into the latched position under the effect of the biasing means.

A preferred multiple latch, door lock mechanism according to the invention of Australian patent application no. 24841/97 comprises a backing piece adapted to be secured to a surface of a door, a master crank mechanism mounted on said backing piece adjacent the free edge of the door at or near the mid-point thereof, a slave crank mechanism mounted on said backing piece at or near the middle point of said surface, linking means connecting the crank mechanisms such that rotation of the master crank mechanism causes corresponding rotation of the slave crank mechanism, at least three latch bolts mounted on said backing piece respectively positioned at or near midpoints of associated door edges, at least three connecting rods extending respectively from the latch bolts to a said crank mechanism and effecting projection and retraction of the latch bolts into latched and unlatched positions respectively in response to rotation of the master crank mechanism, biasing means urging said latch bolts into the latched positions, and detent means automatically engaging a said crank mechanism when the latch bolts are in their unlatched positions to then hold the bolts in their unlatched positions; said detent means including a striker element adapted to contact o the door surround as the door moves into its closed position and thereby disengage the detent means to enable the latch bolts to move into their latched position under the effect of the biasing means.

In one aspect, the present invention provides a door lock mechanism i comprising: a plurality of flat ended latch bolts; a biasing means urging each latch bolt into a latched position wherein each bolt projects beyond an edge of a door; an operating mechanism including: a rotatable handle; a primary actuation mechanism acted on by said rotatable handle, said primary actuation mechanism including a toothed cog and at least one 30 toothed member engaging with said cog whereby rotation of said rotatable handle causes rotation of said cog to thereby cause movement of said at least one toothed member and, directly or indirectly, thereby cause at least one latch bolt of the plurality of latch bolts to be drawn against the effect of the biasing means into an unlatched, retracted position; and a secondary actuation mechanism arranged at a position spaced from the primary actuation mechanism, the secondary actuation mechanism acted on by the primary actuation mechanism whereby rotation of said rotatable handle causes rotation of said cog to, directly or indirectly, actuate said secondary actuation mechanism to thereby cause at least some latch bolts of the plurality of latch bolts to be drawn against the effect of the biasing means into an unlatched, retracted position; a connecting means for connecting the at least some latch bolts to the secondary actuation mechanism; and a detent means automatically engaging one of the operating mechanism and at least one latch bolt of the plurality of latch bolts when the latch bolt is in the unlatched position to hold the at least one bolt in the unlatched position; said detent means including a striker element adapted to contact a door surround as the door moves into its closed position and thereby disengage the detent means to enable the at least one latch bolt to move into the latched position under the effect of the biasing means.

Preferably, rotation of the toothed cog causes reciprocating movement of at least one toothed member. The at least one toothed member preferably comprises at least one toothed arm.

The secondary actuation mechanism suitably comprises at least one rotatable member.

ooo.

The at least one rotatable member may comprise one or more discs. Suitably, S. 20 actuation of the primary actuation mechanism causes rotation of the at least one rotatable member which causes retraction of the latch bolts that are operatively 0. connected thereto.

The biasing means may be one or more springs arranged as shown in Australian patent application no. 24841/97. Alternatively, and more preferably, the 25 biasing means comprises a loading spring (or more than one) that acts on the secondary actuation member.

For preference four latch bolts are provided, one at each edge of the door, and for descriptive convenience the invention is described according hereinafter, but it will be appreciated that one or two of the latch bolts and the corresponding connecting rods may be omitted without departing from the scope of the invention.

In one class of embodiments two horizontally moveable latch bolts are connected to the primary actuation mechanism, and two vertically moveable latch bolts are connected to the secondary actuation mechanism.

In another, more preferred, class of embodiments the primary actuation mechanism is connected by a connecting rod to one of the latch bolts and is linked by the connecting means to the secondary actuation mechanism and the secondary actuation mechanism is connected by respective connecting rods to the remaining three latch bolts.

Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is solely for the purpose of providing a context for the present invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed before the priority date of each claim of this application.

Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

By way of example, an embodiment of the above described invention is described in more detail hereinafter with reference to the accompanying drawings. In the accompanying drawings, Figures 1 to 6 show the invention described in Australian patent application no 24841/97, whilst Figures 7 to 12 show the improvements or modifications thereto the subject of the present application.

Figure 1 is a perspective view from the inside of an external door fitted with a lock, having four latch bolts, according to Australian patent application no. 24841/97.

o Figure 2 is a rear elevation of the lock appearing in figure 1 with its cover plates removed, parts of its vertically extending components cut away and shown with the latch bolts in their latched positions.

Figure 3 is a view similar to figure 2 showing the lock with the latch bolts in their unlatched positions.

25 Figure 4 is a plan view of a free edge portion of door and lock of figure 1 in a nearly closed position.

Figure 5 is a sectional elevation taken on line 5-5 of figure 3.

Figure 6 is an enlarged, perspective view of an operating shaft and associated •shaft mounted components of the lock of figure 1.

Figure 7 is an exploded, rear view of a lock in accordance with the present invention.

Figure 8 is a perspective view of the lock of Figure 7.

Figure 9 is an enlarged view of a part of the lock of Figure 7 with a handle cover plate fitted thereto Figure 10 is a similar view to that of Figure 9, but with the handle cover plate removed.

Figure 11 is a perspective view of the central disks arrangement of the lock of Figures 7 to 10; and the description continues on page 6 9 9 *9 CA01036008.6 6 Figure 12 is an underneath perspective view of the central disks arrangement of the lock shown in Figures 7, to The illustrated lock shown in Figures 1 to 6 is shown applied to an external door 7 operating within a doorway frame 8. It is key operable from the outside by means of a conventional key 9 co-acting with a conventional multiple pin and cylinder lock barrel 10, and manually operable from the inside by means of a rotatable handle 11 on a spindle 12 extending from the barrel 10 to the handle 11.

The lock comprises a backing piece in the nature of a cruciform plate comprising four arms 13, 14, 15 and 16 respectively extending from a central junction 17. Arm 14 comprises two partially overlapping strips 18 and 19 respectively. Strip 18 is longitudinally slotted at and is secured to strip 19 by screws 21 extending through the slots 20. Thus, the strips 19 and are able to be fixed to each other at any desired degree of overlap so that the length of the arm 14 may be adjusted to suit the dimensions of the door to which the mechanism is to be applied. It will be seen from the drawings that arms 13, 15 and 16 are similarly adjustable in length and they need no further description in this respect. In use, the backing piece may be held by screws or bolts to an inside face of the door 7, with the junction 17 at or near the middle of the door and the arms 13 to 16 extending vertically or horizontally, as the case may be, to, or near to, the respective edges of the door.

The spindle 12 extends through the arm 13 of the backing piece near the end thereof.

That spindle is preferable journaled in a bearing element 22 rotatably mounted to the backing piece. Thus, in conventional manner, the spindle 12 extends through the backing piece and engages a connecting tongue 23 of the conventional key operating barrel 10, accessible from the opposite side of the door to that on which the subject lock mechanism is mounted.

:"The handle spindle 12 also extends through a double throw master crank 24 with its throws 1800 apart. That master crank 24 may be generally semi-circular plate with the spindle extending perpendicularly through the mid-point of its straight edge. The crank 24 is either nonrotatably mounted upon the spindle 12 or its integral therewith, and is provided with pivot holes near the ends of its straight edge whereby it may be pivotally connected to a connecting rod 26 and an oppositely directed link rod 27 respectively. The handle spindle 12 may rotate CA01036008.6 7 through 900, whereby the rods 26 and 27 are pushed apart to a position where the rods are in near in alignment with the crank's straight edge (as shown in figure or pulled towards each other to a position where they are substantially out of alignment with the straight edge (as shown in figure Each so called rod 26 and 27 may be a length of stout wire or light weight square sectioned tube or other light rigid member and is provided with eyes at each end of the pivotal connection to contiguous components.

The link rod 27 extends from the master crank plate 24 to a slave crank disk 30 and is connected thereto by a pivot pin 31 extending from the disk 30 through the rod or vice versa.

Thus the crank disk 30 is caused to rotate in concert with the crank plate 24.

Three further connecting rods 33, 34 and 35 respectively extend from the slave crank disk For preference link rod 27 is in two parts 28 and 29a that may be secured together with various degrees of overlap, or is otherwise rendered length adjustable, to enable the rod length to be adjusted to suit doors of different dimensions.

The connecting rods 33, 34 and 35 are similarly adjustable in length and need no further description in that respect.

The ends of the connecting rods 26, 33 and 34 remote from the crank mechanisms are respectively pivotally connected to flat ended latch bolts 36, 37 and 38 mounted in tubular or other guides 30, 40 and 41, so that rotation of the door handle 11 causes axial projection or 20 retraction of the latch bolts. Connecting rod 35 is similarly connected to a similarly mounted latch bolt not shown in the drawings.

Biasing means, for example, a loading spring 42 urges connecting rod 34 into the ***position shown in figure 2 whereby latch bolt 38 is urged into the projected position shown in that figure, wherein it projects through an opening in a striker plate 43 secured to the door frame 25 8. The spring 42 may be assisted by or entirely replaced by a spiral clock spring (not shown) applying a rotational bias upon the crank disk 30 or the crank plate 24. By virtue of the crank mechanisms, latch bolts 36 and 37 are simultaneously urged into three projected positions CA01 036008.6 8 wherein they engage striker plates 44 and 45 respectively. Likewise the fourth latch bolt is urged into engagement with a fourth striker plate 49.

In accordance with the invention, detent means are provide to hold the latch bolts in their retracted or unlatched positions when the door has been opened. Those means, in this instance, comprise, a push rod 46 including a striker tip 47 projecting axially of the push rod at one end thereof, a loading spring 48 urging the push rod towards said one end, and a rotary sprag When the door is open and the latch bolts are retracted, the loading spring 48, by way of the push rod 46, urges the sprag 50 into engagement with a notch 51 (see figure 2) in the curved periphery of the crank plate 24. In other embodiments the sprag may bear against a step in, or projecting extending from, the curved edge of the plate 24. In any event, this prevents rotation of the plate 24 against the effect of the biasing means and this, in turn, ensures that the latch bolts remains retracted clear of the striker plates 44, 45, 43 and 49. However, if the door is swung shut, for example by operation of a door closer 53, the striker tip 47 contacts an inclined cam face 52 (see Figure 4) on the striker plate 44 causing the push rod 46 to be moved against the effect of the spring 48 so as to disengage the sprag 50 from the crank plate 24 and allow the loading spring 42 to effect projection of the latch bolts into engagement with the openings in the respective striker plates, whereby the door is latched shut.

In other embodiments the striker released detent means may take other forms and may engage other parts of the lock mechanism to hold it against movement until the door is pushed Sshut.

The improvements or modifications that are the subject of the present application are shown in Figures 7 to 12.

Turning now to Figures 7 to 12, the locking mechanism 100 in accordance with the 25 present invention comprises four arms, 101, 102, 103, 104. The arms 101 to 104 are preferably of adjustable length as has been described with reference to arms 13, 14, 15 and 16 as shown in figures 2 to CA01036008.6 9 The primary actuation mechanism includes a toothed cog 105 having a spindle 106 either non-rotatably mounted thereto or integrally formed therewith. The primary actuation mechanism further includes a first toothed arm 107 and second toothed arm 108. The first toothed arm 107 is rigidly connected to a downwardly extending arm 109 which, in turn, is connected to latchbolt 110. Second toothed arm 108 is connected to or carries upwardly projecting arm 111, which is rigidly connected to arm 112. Arm 112 connects to a central disk arrangement 113. Central disk arrangement 113 comprises an upper disk 114 and a lower disk 115. This is best shown in figures 8, 11 and 12. Upper disk 114 has a cutaway portion 116 to allow clearance for arm 112.

The upper disk 114 has arms 117, 118 connected thereto. Arm 112 is also connected to upper disk 114 by a pin or bolt that passes through aperture 119 in upper disk 114. Lower disk 115 has 120 connected there. Respective arms 117, 118, 120 are connected to respective latch bolts 121, 122, 123.

As best shown in figures 11 and 12, upper disk 114 and lower disk 115 are both mounted about a common axis 124. Therefore, upper disk 114 and lower disk 115 rotate about the same axis of rotation.

A circular spring 125 is fitted about a downwardly depending projection from lower disk 115. Circular spring 125 acts to bias the latch bolts into an open position.

The apparatus shown in figures 7 to 12 also includes a detent means to hold the latch bolts in their retracted or unlatched positions when the door has been opened. The detent means is essentially similar to that as shown with reference to figures 2 to 5. In particular, the detent means includes a push rod 126 having a striker tip 127 projecting axially of the push rod at one end thereof. A loading spring and a sprag (not shown), that are generally similar to the loading spring and sprag of figures 2 to 5 are also included. Operation of the detent means of figures 7 to 12 is generally similar to the operation of the similar detent means described in figures 2 to However, the sprag may engage with either the toothed cog 105 or it may engage with a smaller disk fixed to or mounted underneath toothed cog 105, which smaller disk has a detent formed in an outer periphery thereof to enable such sprag to engage therewith.

CA01036008.6 Operation of the locking mechanism shown in figure 7 to 12 is as follows. A handle (not shown), which is connected to spindle 106, is rotated. This causes rotation of toothed cog 105, which thereafter causes linear movement in toothed arms 107, 108. With particular reference to figure 7, rotation of toothed cog 105 in a counter clockwise direction causes toothed arm 107 to move to the left, which then retracts latch bolt 110 to the retracted position. Similarly, toothed arm 108 moves to the right, which then moves arm 112 to the right, thereby causing rotation of disks 114, 115 in a counter clockwise direction. As a result, arms 117, 118 and 120 subsequently move their respective latch bolts 121, 122, 123 into the retracted position. The detent means then engages and the latch bolts are held in their retracted position. It will be appreciated that rotation of the disks 114, 115 in this fashion is effected against the biasing effect of circular spring 125. Similarly, the detent means holds the latch bolts in the retracted position against the biassing effect of the spring 125.

The invention alos encompasses the possibility of the door handle being either "lefthanded" or "right-handed", with the result that the door handle may be rotated to the left or to the right to open the door.

When the door is swung closed, the striker tip 127 contacts the door jam. In a fashion substantially identical to that as described with reference to figures 2 to 5, this causes the detent means to disengage and thereby allows the latch bolts to return to the extended or closed position.

In some embodiments, the spindle 12 is attached via a square shaft to a door handle.

The arrangement shown in Figure 6, in which a lock barrel 10 is operated by a key 9, may be replaced by a key-operated, lockable handle. This may make the door easier to open. A protective shroud may be placed around the handle on the exterior of the door to protect against attempted illegal manipulation of the door. The protective shroud may even be bolted through the exterior skin of the door.

A handle cover plate 128 may be mounted over the spindle 106. This can enhance the security of the door. A protection shroud may be bolted to the handle cover plate.

The embodiment of the present invention shown in Figure 7 to 12 has the advantage that the handle does not need to be turned through a large angle to actuate the lock. Indeed, the CA01036008.6 11 particular embodiment shown in Figure 7 enables the lock to be actuated by turning the handle through as little as 57°.

The foregoing describes embodiments of the present invention and modifications, obvious to those skilled in the art can be made thereto, without departing from the scope of the present invention.

*e e -*7

Claims (10)

1. A door lock mechanism comprising: a plurality of flat ended latch bolts; a biasing means urging each latch bolt into a latched position wherein each bolt projects beyond an edge of a door; an operating mechanism including: a rotatable handle; a primary actuation mechanism acted on by said rotatable handle, said primary actuation mechanism including a toothed cog and at least one toothed member engaging with said cog whereby rotation of said rotatable handle causes rotation of said cog to thereby cause movement of said at least one toothed member and, directly or indirectly, thereby cause at least one latch bolt of the plurality of latch bolts to be drawn against the effect of the biasing means into an unlatched, retracted position; and a secondary actuation mechanism arranged at a position spaced from the primary actuation mechanism, the secondary actuation mechanism acted on by the primary actuation mechanism whereby rotation of said rotatable handle causes rotation of said cog to, directly or indirectly, actuate said secondary actuation mechanism to thereby cause at least some latch bolts of the plurality of latch bolts to be drawn against the effect of the biasing means into an unlatched, retracted position; a connecting means for connecting the at least some latch bolts to the secondary actuation mechanism; and a detent means automatically engaging one of the operating mechanism and at 25 least one latch bolt of the plurality of latch bolts when the latch bolt is in the unlatched .o position to hold the at least one bolt in the unlatched position; said detent means including a striker element adapted to contact a door surround as the door moves into its closed position and thereby disengage the detent means to enable the at least one latch bolt to move into the latched position under the effect of the biasing means.

2. A door lock mechanism as claimed in claim 1 wherein rotation of the toothed cog causes linear movement of the at least one toothed member.

3. A door lock mechanism as claimed in claim 1 or claim 2 wherein the at least one toothed member comprises at least one toothed arm. 13

4. A door lock mechanism as claimed in any one of the preceding claims wherein the secondary actuation mechanism comprises at least one rotatable disc. A door lock mechanism as claimed in claim 4 wherein the secondary actuation mechanism comprises two discs mounted in axial alignment.

6. A door lock mechanism as claimed in any one of the preceding claims wherein the biasing means comprises one or more springs.

7. A door lock mechanism as claimed in claim 6 wherein the one or more springs biases the secondary actuation mechanism.

8. A door lock mechanism as claimed in any one of claims 1 to 7 further comprising a backing piece adapted to be secured flatly against a face of the door and comprising a plurality of arms extending radially from ajunction, wherein said secondary actuation mechanism is mounted to said junction, said primary actuation mechanism is mounted to one of said arms at a position spaced from e0. said junction, and said latch bolts are respectively mounted to the arms at or near ends thereof. o:9. A door lock mechanism according to claim 8 wherein said arms, and said connecting means are each length adjustable. A door lock mechanism according to claim 9 wherein each arm comprises two partially overlapping strips adapted to be fixed together and to said door.

11. A door lock mechanism according to any one of the preceding claims wherein said detent means comprises a push rod including a striker tip projecting axially of the push rod at one end thereof, a loading spring urging the push rod towards said one end, a movable sprag adapted to engage said operating mechanism, an inclined cam face fixed to the door surround adjacent an edge of the door when closed that is contacted by the striker tip as the door is closed, to move said sprag and free said mechanism. 14

12. A door lock mechanism according to claim 11 wherein the sprag engages the primary actuation mechanism.

13. A door lock mechanism substantially as hereinbefore described with reference to Figures 7 and 8. Dated this fourth day of August 2006 D. and V. O'Neill Pty Ltd Patent Attorneys for the Applicant: F B RICE CO e* *o *e e