538128
No: 538128
Date: 9 February 2005
NEW ZEALAND
Patents Act 1953
COMPLETE SPECIFICATION
A LATCH DEVICE FOR A SLIDING DOOR CLOSURE
WE, ASSA ABLOY NEW ZEALAND LIMITED a New Zealand company of 6 Armstrong Road, North Harbour Industrial Estate, Albany, Auckland, New Zealand (formerly of 6 Portsmouth Road, Miramar, Wellington, New Zealand) hereby declare this invention to be described in the following statement:
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SPEC!807
intellectual property office of n.z.
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BACKGROUND TO THE INVENTION
INTELLECTUAL PROPERTY OrH^. ' OF i\u
This invention relates to a latch device for a sliding closure. In particular, the invention relates to a latch device, which is suitable for latching of a sliding window or door.
It is known to provide a lockable latch for a sliding closure, more particularly, a sliding window. In Australian patent specification 627346 there is disclosed a lockable latch, which comprises a body having a handle, the body incorporating a longitudinal bead, which is pivotally engaged in a groove of a sliding window sash. The body further includes a projection, which engages with a chamfered edge of an adjacent jamb of the window when the sash is in the closed position in the window frame. The body can thus be pivoted to release the projection from the chamfered edge to enable the sash to be slid to an open position.
With the arrangement in AU 627346, the projection has an inclined edge, which engages with the chamfered edge as the sash moves to the closed position. The projection thus rides up and over the chamfered edge such that automatic latching occurs at the point at which the sash reaches its fully closed position.
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A problem arising from this form of automatic or self-latching device is that the entire body and handle moves during the re-latching operation. This can be undesirable as, for example, part of the user's hand e.g. fingers, can become trapped between the body/handle and part of the sash which while not necessarily causing a significant injury, can nevertheless be painful.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a latch device for a sliding closure whereby the self-latching operation is independent of any movement of the part of the latch device, which is operable to unlatch the latch device.
Broadly according to one aspect of the invention there is provided a latch device for latching together a first member and a second member between which relative sliding movement can occur, the latch device including a body pivotally mountable to said first member, a handle grippable by a user to pivotally move the body relative to the first member, a rotatable catch having means for mounting the rotatable catch to the first member such that the rotatable catch is able to be rotated relative to the first member and independent of pivotal movement of the body, the rotatable catch having an engagement means which in a first position of the rotatable catch engages with said second member to prevent relative movement between the first and second members from occurring, means for coupling the rotatable catch to the body to permit the body to move the rotatable catch to a second position where relative SPECl 807 FEBRUARY 2006
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movement between the first and second members can occur, and moving means to move the rotatable catch to said first position in the event of the rotatable catch being moved away from the first position other than by movement of the body.
For ease of reference and description the following disclosure will describe the latch device in conjunction with a window sash slidingly mounted in a window frame. This is by way of illustration. The latch device of the present invention is not limited to window applications and can be used in other applications such as with sliding doors.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following more detailed description of the invention reference will be made to the accompanying drawings in which: -
Figure 1 is an exploded view of the components of the latch device according to our preferred embodiment,
Figure 2 is an illustration in the nature of a cross-section which illustrates the operation of the latch device where self-latching occurs as a window sash moves to its closed position relative to a jamb portion of a window frame,
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Figure 3 is a view similar to Figure 2 but showing the latch device in the latched and locked position,
Figure 4 is yet a further similar view but showing the latch device moved to an unlatched orientation relative to the jamb and sash,
Figure 5 is an exploded view of the components of the rotating catch assembly of the latch device,
Figure 6 is an assembled view of the rotating catch assembly,
Figure 7 is a sectioned view of the lock body and catch assembly, the section having been taken through one of the spring lifters,
Figure 8 is a further perspective view of the lock body, and
Figure 9 is a perspective view of the catch body.
DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION
Referring firstly to Figure 1, the latch device includes a lock body 10 which, in the preferred and illustrated form of the invention, is of a one-piece construction. Engageable in lock body 10 is a lock cylinder 11 of known construction. In the SPECl807 FEBRUARY 2006
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accompanying drawings, the lock cylinder 11 is shown in combination with a lock key K.
A rotating catch assembly 12 comprises a rotatable catch IB, a sliding lock tab 14 and a pair of springs 1 5. These components are shown in Figure 1 and in more detail in Figures 5 and 6.
The rotatable catch 13 is, in a preferred form, a body 16 of unitary construction which is of generally elongate form. The catch body 16 incorporates a generally cylindrical element 17 which, in the preferred form of the invention, is shown as being in one piece extending for substantially the full length of the body 16. However, in an alternative arrangement, two or more aligned cylindrical lengths could combine to form the generally elongate cylindrical element 1 7.
The cylindrical element 17 effectively forms a pair of projecting stub axles 17a. These rotatably engage with the lock body 10 as hereafter described.
The lock body also 10 includes a pair of aligned but spaced apart cylindrical elements 19. These form axles which engage in and are rotatably captured with a groove 18 in the first member which in the illustrated arrangement forms a jamb J of the window frame.
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As can be seen in Figure 1 the inner ends of cylindrical elements 19 have bearing recesses 19a into which stub axles 17a can engage. Preferably the stub axles 17a snap fit into bearing recesses 19a. Thus the axis of rotation of stub axles 17a is substantially coaxial with the axis of rotation of cylindrical elements 1 9.
In the illustrated arrangement the cylindrical elements 19 are rotatably captured in the groove 18. As a consequence, the cylindrical elements 19 can rotate in the groove as will hereinafter be apparent.
In the preferred form the lock body 10 is assembled to the jamb J by the cylindrical element 1 9 being fed in from the end so as to be located rotatably.
The lock body 10 incorporates a cavity 20 (see Figure 1) into which the lock cylinder 11 can engage in a conventional manner. The lock body 10 further includes a lip or projecting portion 21 which forms a hand grippable handle.
The rotatable catch body 16 further includes an elongate slot 22 at each end of which is a cavity 23. Into each cavity end of 23 a spring 15 is engaged (see Figure 5). The other end of each of spring 15 engages with an end part 24 of the sliding lock tab 14, when the sliding lock tab 14 is slidingly engaged in elongate slot 22.
The sliding lock tab 14 further includes a first pair of legs 25. The distal end of each leg 25 includes an abutment 26.
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The sliding lock tab 14 further includes a second pair of legs 27, each of which has a ramped (28) distal end.
As shown in Figure 5, the rotating catch assembly 12 is assembled by placing the ends of the springs 15 into the respective cavities 23 and then inserting the sliding lock tab 1 4 into the elongate slot 22. The sliding lock tab 1 4 is then pushed against the biasing effect of the springs 15, until such time as the abutments 26 of legs 25 engage in recesses 29 formed in the body 16 of the rotatable catch 13. This assembled arrangement is more particularly shown in Figure 6.
A large recess 30 is formed in the catch body 1 6 to form a clearance for the end of the lock cylinder 11 in the assembled state of the latch device.
The rotatable catch body 16 further includes a tooth-like projection 31 which, as can be seen in Figure 1, is discontinuous because of the presence of the large recess 30. Therefore there are effectively two spaced apart projections 31.
In the assembled form of the latch device, as for example shown in Figure 3, the tooth-like projections 31 engage behind a wall, flange or projection W of the sash S. When so engaged, the sash S is latched in the closed position relative to jamb J..
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As shown in Figures 2, 3 and 4, the assembled rotating catch assembly 12 and lock body 10 with lock cylinder 11 are mounted with the jamb j by the respective cylindrical elements 17 and 19 being effectively rotatably captured within groove 18. Both the rotatable catch body 16 and the lock body 10 incorporate projections 32 and 33. The ends of projections 32 and 33 form stops to limit the extent of rotation by each engaging with a surface S of jamb J.
Referring to Figure 3, the latch device is shown in the latched position. Because of the biasing effect of the springs 15, the sliding lock tab 14 projects to its fullest extent from the rotating catch body 16 e.g. as shown in Figure 6. The surface 34 of the sliding lock tab 14 thus engages with flange F of the jamb J (see e.g. Figure 3).
In this position, the lock pin P of the cylinder 11 engages with the inner surface 35 of the sliding lock tab 14. This locks the lock tab 14 in position which means that the lock body 10 is prevented from rotating about the axis of rotation (established by the cylindrical elements 1 9 in groove 1 8) because of lock tab 14 engaging flange F.
However, if the key K is rotated in the direction shown by the arrow in Figure 3, the lock pin P is moved away which in turn removes the locking affect on the sliding lock tab 14. Consequently, the lock body 10 is free to be rotated (about the axis of rotation of cylindrical elements 19 in groove 1 8) to the position shown in Figure 4.
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When the lock body 10 is rotated in this manner to unlatch the sash the latch assembly 12 is constrained to rotate with the lock body 10. To this end the lock body 1 0 includes a pair of tabs 36. When the lock body 1 0 is rotated in the opening direction the tabs 36 engage with the faces 37 on the latch body 16 thereby causing the latch assembly 1 2 to rotate in the opening direction.
As can be seen in Figure 4 the sliding lock tab 14 has been freed up to slide into the rotatable catch body 16, though the limit of the sliding movement in the slot 22 is determined by the head of the sliding lock tab 14 coming into engagement with the body of the rotatable catch 16. Thus, as shown in Figure 4, the extent by which the sliding lock tab 14 can slide within the catch body 16, determines the extent by which the lock body 10 can rotate relative to jamb J. This limited rotation of the lock body 1 0 is, however, sufficient for the tooth-like projections 31 to clear the wall W of the sash S, thereby freeing the sash so that it can move relative to jamb J i.e. be slid in the opening direction.
Upon the user having released the lock body 10 from the position shown in Figure 4, the lock body 10 reverts to the position shown in Figure 3 i.e. the abutments 32 and 33 of the rotating catch 12 and lock body 10 come into engagement with wall surface S of jamb J.
Upon the sash S being slid in the direction of the arrow shown in Figure 2 to a closed position, the surface C of wall W engages with the inclined surface 31a of the tooth SPECl807 FEBRUARY 2006
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shaped projections 31 of the rotatable catch body 1 6. This forces the rotating catch assembly 12 to rotate (independent of the lock body) so as to clear wall W. As the sash S is slid further the latch assembly 12 is forced by springs 15 back into the latched position behind wall W.
Once the sash S has moved to its fully closed position, the tooth-like projections 31 clear wall W and under the biasing action of the locking tab 14, the rotating lock assembly 1 2 rotates back into the position shown in Figure 3, whereupon the sash is latched and locked.
The latch device according to the present invention can be used in conjunction with sliding closures such as sliding doors and sliding windows. It provides an effective means of automatically locking when the closure is moved into the closed position, this self-latching and locking operation occurring independent of movement of the lock body. Accordingly, there is prevented the possibility of a user's hand becoming jammed between the lock body and some other adjacent surface during the closing and latching of the closure element.
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