CLOSING MECHANISM FOR A SLIDING DOOR OR WINDOW

FIELD OF INVENTION

[0001 ] The present invention relates to a closing mechanism for a sliding door or window,

[0002] More particularly, the present invention relates to a closing mechanism for a sliding door or window enabling automatic closing of the door or window under controlled conditions.

BACKGROUND TO INVENTION

[0003] It is known to provide closing mechanisms for building closures, such as doors or windows, to automatically cause the closure to close after having being opened. Some examples of these closing mechanisms include the use of hydraulic means, counterweights and reel springs for moving the closure

[0004] However, the majority of these closing mechanisms suffer from one or more deficiencies. One such problem is that the door builds up a relatively large kinetic energy from the force applied by the closing mechanism, resulting i the speed of closing the door increasing as it is progressively closed and subsequently slamming closed against the side jamb. For doors that are only partially opened before being automatically closed, the resultant speed and slamming closed are within tolerable limits. However, in most cases, a door that is automatically closed from a fully opened position does so wit sufficient force that it can cause severe injuries to persons, e.g. if a child were to have their fingers caught between the door and the side jamb.

[0005] Furthermore, the slamming closed tends to cause a loud noise, often being of great annoyance to a man people, and can also result in damage to the door or door lock, side jamb or a window pane located within the door. [0006] The present invention attempts to overcome, at least in part, the aforementioned disadvantages of previous closing mechanisms for a sliding door or window.

SUMMARY OF INVENTION

[0007] According- to one aspect of the present invention, there is provided a closing mechanism for returning a door siidable within a frame from an ope positio to a closed position at which the door abuts a side jamb, the closing mechanism comprising:

a reel supporting an elongated cable, wherein the elongated cable is adapted to be extended between the door and the side jamb;

biasing means for exerting a biasing force o the reel to wind up the cable for sliding the door to its closed position: and

a damper being adapted to at least partially counteract the biasing force before the door is fully closed.

[0008] The closing mechanism may include a housing rotatahly supporting the reel

[0009] The closing mechanism may include attachment means for attaching the housing to the door.

[0010] The biasing means may be a spring reel assembl comprising a reel spring joined to the reel.

[001 1 ] The damper may be piston-and-cyimder shock absorber.

[0012] The damper may be operatively joined to a striker, the striker being adapted to contact, a latch mounted on the frame to effect operation of the damper.

[00 i 3] The striker may be linearly movably supported relative to the reel.

[0014] The striker may be pivotally supported relative to the reel.

[0015] The striker may be pivotally supported relative to the damper. [0016] Tire strike ma have opposed claws each being adapted to contact the latch, whereby one claw is adapted to contact the latc h during opening of the door and an opposed claw is adapted to contact the latch during closing of the door,

[0017] The opposed claws may be selectively retractable away from the latch, in use being adapted to release the latch from the striker after making contact therewith.

[0018] The opposed claws may be pivo tally joined to each other.

[0 19] The opposed claws may each include projecting lugs for location in a channel for controlling movement of the striker,

[0020] The closure may be a sliding door or a sliding window.

[0021] The invention extends to a closure comprising a closing mechanism as described herein.

BRIEF DESCRIPTION OF DRAWINGS

[0022] The present invention will now be described, by wa of example, with reference to the accompanying drawings, in which:

Figure I is a side view of a sliding door to which a closing mechanism according to one embodiment of the invention is attached, the sliding door being shown in a open position;

Figure 2 i an enlarged scale perspective view of the closing mechanism according to the invention, being shown with its cover removed and in a first or operative "open" position;

Figure 3 is a perspective view of the closing mechanism of Figure 2, being shown in a second or operative "closed" position,

DESCRIPTION OF PREFERRED EMBODIMENT

[0023] Referring to Figure 1 of the drawings, there is shown a closing mechanism 10 for a sliding door or window. The closing mechanism 10 is particularly suited for controlling the automatic closing of horizontally sliding doors and windows. Figure 1 shows the closing mechanism 10 being joined to a sliding door 12, near its upper edge or top rail, for sliding the door 12 within its frame 1.4. The frame 1.4 has a head 16 and a side jamb 18, The closing mechanism 10 is joined to the door 12 by conventional attachment means, e.g. by screws.

[0024] As shown in Figures 2 and 3, the closing mechani m 10 includes a housing 20 supporting a biasing means 22, the latter preferably being in the form, of a conventional -type spring reel assembly . The housing 20 has a removable cover (not shown) permitting access to the internal parts of the closing mechanism 10. The biasing means 22 includes a central axle 24 fixedly supported by the housing 20. A reel spring 26 is joined at its inner end to the central axle 24 and at its opposed outer end to a reel 28 that is rotatahly mounted relative to the central axle 24.

[0025] A cable 30, or other type of flexible elongate member, is joined at its one end to the reel 28 and is wound thereon. The cable 30 can be a string, rope, chain or any other type of line and is preferably made of a non-elastic material. The cable 30 is adapted to be unwound from the reel 28 by pulling it with a unwinding force sufficient to overcome the biasing action of the reel spring 26, thereby permitting the cable 30 to be pulled out from the housing 20. When the unwinding force is removed, the reel spring 26 is adapted to rewind the cable 30 onto the reel 28. A number of cable guides 32 are located within the housing 20 to guide the cable 30 between the reel 28 and the outside of the housing 20, thereby to avoid the cable 30 from becoming entangled within the housing 20 during use.

[0026] In one embodiment of the invention, as shown in Figure 1 , the cable 30 has its remote free end 34 anchored to the side jamb 18. In another embodiment (not illustrated), the remote free end 34 of the cable can be anchored to a cable collector that is anchored onto the side jamb 1.8. I yet another embodiment, as represented in Figures 2 and 3, the cable 30 ca be looped around a cable loop 36 and returned to a cable collector 38 that is located within the housing 20, The cable loop 36 is anchored onto the side jamb 18 and is simply an arcuate guide that slidably locates tire cable 30 and reduces wearing of the cable 30 while it slides through the cable loop 36,

[0027] In use, an opening movement applied by a person to the door 12 will provide sufficient force to extract the cable 30 from the reel 28. This extraction causes the reel 28 to rotate, which consequently causes the reel spring 26 to wind u on itself around the central axle 24 resulting in tension within the reel spring 26, When the door 12 is released by the person, the wound reel spring 26 acts to rotate the reel 28 to rewind the cable 30, thus pulling the door 12 towards the side jamb 18. It should be noted that in such use, no cable 30 will be wound on the cable collector 38, Howe ver, if any cable 30 had been wound onto the cable collector 38 (as will be described later hefein), then the rotation of reel 28 will firstly unwind all that cable 30 front the cable collector 38, until the latter reaches a deadlock, before the door 12 will start its closing movement.

[0028] The closing mechanism 10 is further provided with a braking means 40 for braking the biasing means 22 thereby to prevent automatic closing of the door 1.2. The braking means 40 comprises a lever 42 that is movable between a disengaged position, wherein it is spaced apart from the reel 28, and an engaged position, wherein it engages with the reel 28 to prevent rotation thereof in a direction for closing the door 12, The reel 28 has a plurality of ratchet teeth 44 that are arranged to engage with a complementary pawl 46 extending from the lever 42. The pawl 46 can have multiple protrusions so that it is able to engage with multiple ratchet teeth 44 simultaneously. The ratchet teeth 44 can be provided along the perimeter of the reel 28 or be provided on a side of th reel 28 concentric with the perimeter thereof.

[0029] The braking means 40 is normally biased into its disengaged position by a coil spring 48. A trigger 50 extends from the lever 42 to outside the housing 20 so that a person, in use, can grip the trigger 50 and overcome the bias of the coil spring 48 to slide the lever 42 towards the reel 28 -until the pawl 46 engages the ratchet teet 44. Although the coil spring 48 is shown in the drawings as a compression coil spring, it is envisaged that, it could be an expansion coil spring or a leaf spring, either of which would need to be suitably relocated for conventional use thereof.

[0030] In use, when the door 12 has been opened by a person and it is desired to prevent the door 12 from being automatically closed, then the person can engage the braking means 40 after the door has been opened or allowed to automatically close to the desired extent. By moving the lever 42 towards the reel 28, the pawl 46 engages the ratchet teeth 44 and accordingly prevents further closing rotation of the reel 28 (i.e. being rotation in the direction of arrow 52 shown in Figure 2) and thus prevents the reel 28 from winding up the cable 30 and accordingly from closing the door 12. When so engaged, the pawl 46 is held in position by the ratchet teet 44 and the rotational bias of the reel spring 26.

[0031] It is to be understood that when the braking means 40 is engaged, the door 12 is still freely movable by a person and can be manually further opened, partially closed or fully closed. Further opening of the door 12 to a small extent will cause the reel 28 to rotate in the opposite direction to arrow 52, thereby causing the ratchet teeth 44 to release the pawl 46 whereafter the lever 42 will be withdrawn to its disengaged position by the coil spring 48. The door 12 can then either be released for further automatic closure or the braking means 40 re-engaged. The braking means 40 allows single handed operation thereof.

[0032] However, one problem that may be encountered with manually closing the door 12 only partially is that the cable 30 will tend to become slack and hang under its own weight forming a noose within the opening between the door 12 and the side jamb 18. It is for this reason that the closing mechanism 10 is provided with a secondary reel in the form of the cable collector 38 mentioned above. The cable collector 38 has similar features to the biasing means 22, however its reel spring 54 is much weaker than the reel spring 26. As such the reel spring 54 of the cable collector 38 has insufficient force to cause or hinder any movement of the door 12. The reel spring 54 only has sufficient force and is only capable of winding up the cable 30 to remove any slack therein so that the cable remains lightly tension ed and extends substantially linearly between the housing 20 and the side jamb 18, in which positio the cable 30 will be located relatively close and lie parallel to the head 16.

[0033] The closing mechanism 10 further provides a soft-close feature to prevent the door 12 from slamming closed against the side jamb 18. The soft-close feature is in the form of a rocking striker 56, being pivotally supported in the housing 20 at pivot 58. Striker 56 is operatively joined to a damper 60, the latter being of a piston-and-cylinder type having a cylinde 62 fixedly attached to the housing 20 and which locates a movable piston 64 joined at its distal end to the striker 56 at pivot 8, Although not preferable, the damper 60 could be utilised in an inversed configuration.

[0034] The striker 56 has opposed claws 66, 68 projecting therefrom on opposed sides of the pivot 58, which claws 66, 68 are adapted to selectively proj ct outwardly beyond the housing 20 so that they are able to engage wit a latc 70 that is fixedly mounted on the head 16 of the frame 14 (see Figure 1). The claw 66 located proximal to the side jamb 18 is the operative opening claw that contacts against the latch 70 when the door 12 is moved towards its open position, whereas the claw 68 located distal to the side jamb I S is the operative closing claw that contacts against the latch 70 when the door 12 is moved towards its closed position.

[0035] Each claw 66, 68 of the striker 56 respectively has a projecting lug 72 , 74 being slidably located in a channel 76 within the bousing 20. A central section 76.1 of channel 76 lies substantially adjacent and parallel to the edge of housing 20. while the opposed ends 76.2 and 76.3 of channel 76 drop off internally within the housing 20. Thus., with a corresponding movement of the piston 64, striker 56 can slide between a door open position as shown in Figure 2, wherein opening claw 66 is substantially located within the housing 20 while closing claw 68 projects therefrom, and a door closed positon as shown in Figure 3, wherein opening claw 66 projects from the housing 20 while closing claw 68 is substantially located within the housing 20. Opening cla 66 and closing claw 68 are also pivotally joined to each other at pivot 78 permitting the lugs 72, 74 to simultaneously slide within the central section 76.1 of channel 76.

[0036] In use, when the door 12 is initially in a closed position and is subsequently moved towards an open position, opening claw 66 contacts against the latch 70 and striker 56 is moved along within channel 76 pulling piston 64 out from the cylinder 62. As piston 64 nears the outer end of its stroke, opening claw 66 follows channel end 76.2 and drops off within the housing 20 to become disengaged from the latch 70 and allowing the door 1 to be further freely opened. The movement of striker 56 within channel 76 automatically causes closing cla 68 to follow channel end 76.3 and rise out from w ithin the housing 20 to project therefrom on an opposite side of latch 70 to opening claw 66.

[0037] Conversely, when the door 12 is moved to be fully closed, closing claw 68 contacts against the latch 70 and striker 56 is moved along within channel 76 pushing piston 64 into cylinder 62. In so doing, damper 60 slows the movement of door 12 to prevent it fr om slamming shut against side jamb 18. As piston 64 nears the end of its stroke, closing claw 68 follows channel end 76.3 and drops off within the housing 20 to become disengaged from the la tch 70. Similarly to the above, the movement of striker 56 automatically cau ses opening claw 66 to again rise out from within the housing 20 to project therefrom.

[0038] Damper 60 is conventionally arranged to provide a force opposing motion in proportion to the speed of closure, such that more rapid movement cause a greater force. In. this manner damper 60 counteracts the action of biasing means 22, thereby allowing the door 12 to be closed whilst ensuring that the door 12 does not slam closed.

[0039] If necessary, latch 70 can be spaced slightly further away from side jamb 18 so that closing claw 68 is released from latch 70 before the door 12 is fully closed. An advantage provided by such relocation is that the damping effect of the damper 60 is withdrawn after the door 12 is substantially closed. This enables the reel spring 26 to again exert its full closing force onto the cable 30 to ensure that the door 12 is fully closed and not left slightly ajar. Obviously, although latch 70 could be located at any distance from the side jamb 18, it is preferable that latch 70 is sufficiently close so that door 12 does not build up any dangerous closing speed after closing claw 68 is released from latch 70.

[0040] Modifications and variations as would be apparent to a skilled addressee are deemed to be within the scope of the present invention.