DOOR LATCH MECHANISM

Abstract: A door latch mechanism mountable in a notch cut in the edge of a door so as to substantially surround said edge of the door, the latch mechanism comprising a handle on each of two opposing sides of a door latch wherein the latch is actuable by either handle, each handle being individually operable and independently communicating with the latch.

Description: DOOR LATCH MECHANISM This invention relates to the field of a door latch mechanism and handle arrangement, primarily but not exclusively for internal doors. Existing door latches of the conventional type have a handle on each side of the door which is rotated in a clockwise or anticlockwise direction to release the latch and thus allow the door to open. Several problems have been identified with latches of the conventional type. For example, the rotating or twisting action required to open the door is, firstly, not particularly intuitive bearing in mind one essentially needs to either pull or push a door open and, secondly, may cause difficulty for persons having arthritis or other weak wrist conditions. Furthermore, the conventional type of door handle and latch is relatively complex to fit to a door because a substantial rebate has to be cut into the edge of the door to receive the latch mechanism, a hole has to be drilled through the door to receive the rotatable handles and a relatively deep recess has to be cut into the door jamb in order to receive the door latch. It is therefore an object of the present invention to provide a door latch and handle arrangement which alleviates the above-described problems. According to a first aspect of the invention there is provided a door latch mechanism mountable in a notch cut in the edge of a door so as to substantially surround said edge of the door, the latch mechanism comprising a handle on each of two opposing sides of a door latch wherein the latch is actuable by either handle, each handle being individually operable and independently communicating with the latch. Since each of the handles operates completely independently of the other, it is possible to configure the handles to operate in a more intuitive way than conventional door handles. For example, the handle on the "push" side of the door can comprise a visually- distinctive push pad which, when pushed, operates the latch. On the "pull" side of the door can be provided a pull handle which can simply be pulled towards the user in order to operate the latch and open the door. This arrangement eliminates the need for conventional twist or rotating handles which are neither intuitive (i.e. which way does one turn the handle?) nor easy to use for those with weak wrists. Preferably, the door latch mechanism comprises a "push" section, an intermediate section and a "pull" section, the push and pull sections being located, in use, on the push and pull sides of a door respectively and said latch being associated with said intermediate section to which the push and pull sections are operatively linked. Ideally, said latch is mounted on a return spring, with each of said push and pull sections abutting the latch. Preferably, compression of said spring causes said latch to retract away from a striker plate so as to enable a door to be opened, said compression being effected by either pushing said push section or pulling said pull section. In a preferred form, said push section further comprises a push pad. Preferably, each of said sections comprises extruded metal, preferably aluminium. Preferably, the latch mechanism further comprises fixing means for fixing said mechanism to a door. In a preferred form, the .latch mechanism further comprises a capping moulding having a raised lip which, in use, conceals edges of a notch in a door in which the mechanism is mounted. This has the advantage of concealing the edges of the notch which has been cut in the door and which may be rough, so as to minimise the risk of injury or snagging clothes etc. Preferably, a wear strip is located intermediate the push section and the latch. In a preferred form, said handles are removeable and replaceable. This has the advantage of enabling a whole range of visually different handles to be available, all of which can be used with the same door latch mechanism. Preferably, the door latch mechanism further comprises a locking mechanism. Preferably, the door latch mechanism is suitable for use with any of the following: an outwardly opening door with a handle on the left hand side thereof; an outwardly opening door with a handle on the right hand side thereof; an inwardly opening door with a handle on the left hand side thereof; an inwardly opening door with a handle on the right hand side thereof. Preferably, the latch mechanism further comprises a packing pad which, in use, is placed intermediate the door and the latch mechanism in order to permit said latch mechanism to be used with a door of less than standard thickness. Interior doors are conventionally of a standard thickness, but the packing pad enables the latch mechanism of the present invention to be readily used with thinner than normal doors . According to a second aspect of the present invention there is provided a method of manufacturing a door latch mechanism as described in any of the preceding paragraphs comprising the steps of extruding an extrusion having a cross-sectional shape suitable for said push section, slicing the extrusion into a plurality of push sections of required thickness and similarly manufacturing the intermediate and pull sections from suitable extrusions. This manufacturing method has the advantage that numerous latch mechanisms can be readily extruded and cut from a single extrusion for each shaped section. Preferred embodiments of the present invention will now be more particularly described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is an exploded view of the door latch mechanism embodying the invention; Figure 2 is a cross-sectional view of the assembled door latch mechanism; Figure 3 is a schematic representation of a person pushing a door open using the latch mechanism, passing through the door and pushing the door closed behind him; Figures 4-6 show in more detail the three stages represented in Figure, 3; Figure 7 is a schematic representation of a person pulling a door open using the latch mechanism, passing through the door and pulling the door closed behind him; Figure 8-10 show in more detail the three stages represented in Figure 7. Referring to Figures 1 and 2, the latch mechanism comprises three key components, each of which is cut from an aluminium extrusion of the desired shape. The first component is the "push" section 1, the second component is an intermediate section 2 and the third component is the "pull" section 3. When assembled, the three sections are slotted together as shown in Figure 2. The push section is provided with a plastic push pad 4 which visually encourages the user to push thereon. The latch mechanism comprises a nylon latch 5, mounted on a return spring 6. The latch and spring are positioned, in use, as illustrated in Figure 2, with both the push section 1 and the pull section 3 abutting the latch as shown. The door latch is mounted to a door simply by cutting a slot 7 in the edge of the door 8, bolting the pre- assembled handle/latch mechanism to the door (the line of the securing bolt is illustrated as item 9 in Figure 1) and finally, screwing a striker plate to the door jamb. This assembly sequence is clearly much simpler than that for a conventional door latch mechanism which requires several recesses to be formed in the door before the latch and handle mechanism can be mounted. The assembled mechanism also comprises upper and lower capping mouldings 11, 11' , each of which has a raised lip 12, 12' which, in use, conceals the cut edges of the slot in the door 8. The capping mouldings are preferably nylon. Cylindrical protrusions 13, 13' on each of the capping mouldings provide bearing surfaces for the hinges of the handle mechanism (which will be described in more detail below) , and flat areas of the mouldings act as bearing surfaces for all other moving components within the mechanism. Tabs projecting from the mouldings provide locations to the extrusions and hold the nut for a securing bolt within the T-slot prior to assembly. Finally, a nylon rod wear strip 14 is located in the push section 1 as illustrated in Figure 1. Screws 15, 15' locate the capping mouldings 11, 11' with respect to the intermediate section 2. The latch and handle mechanism of the present invention can be adapted to fit various types of door, for example: 1. An outwardly opening door with the handle on the left hand side thereof; 2. An outwardly opening door with the handle on the right hand side thereof; 3. An inwardly opening door with the handle on the left hand side thereof; and . An inwardly opening door with the handle on the right hand side thereof. The opening and closing sequence will now be more particularly described for a door of type 2 i.e. an outwardly opening door with the handle on the right hand side thereof. The opening/closing sequence is schematically illustrated in Figure 3 wherein, at a) the user approaches the door and pushes the push pad. At b) the user pushes the door open and passes through the door, with his hand trailing around the profile of the edge of the door until he reaches the pull handle. At c) the user, having grasped the pull handle, can use it to push the door closed behind him. With reference to Figures 2, 4 and 3a), the operation is as follows. Upon the pushing the push pad 4, push section 1 moves in the direction indicated by arrow 4 in Figure 2. During this movement, push section 1 hinges around intermediate section 2 at hinge 16, the interlocked hooks 17 (on push section 1) and 18 (on intermediate section 2) separate and the wear strip 14 at the extreme end of push section 1 travels along the tapered surface of the nylon latch 5 causing spring 6 to be compressed and the latch 5 to retract away from striker plate 10. Once free of the striker plate 10, the door may be swung open as shown in Figure 3b) . Given the ergonomic design of the door latch mechanism, the user's hand slips readily around the edge of the door as shown in Figure 5 upon passing through the door. When the user reaches the pull handle (see Figure 3c) and Figure 6) , the user can intuitively push the door closed behind him. As the user passes through the door and releases his grip on push pad 4, the return spring 6 causes the nylon latch to return by protruding once again from the latch mechanism. Therefore, when the door is pushed closed, the protruding nylon latch 5 initially engages with the outer surface of the striker plate 10 and, upon the meeting of the tapered faces 5a, 10a the latch is forced back into its retracted position, past the protruding end of the striker plate until the original position illustrated in Figure 2 is reached. Figures 7-10 show the reverse process i.e. the user opening and closing a door which opens inwardly. On approaching the door, the user grasps the pull handle as shown in Figure 7a) . He pulls the handle outwardly as illustrated in Figure 8 in order to release the latch. Figure 2 shows that upon pulling the handle 3, the spring 6 and latch 5 would be forced to retract owing to the interaction between finger 19 on the pull section 3 which rests on a seat 20 on the latch 5. The pull section 3 therefore hinges about hinge 21- so that the finger 19 is urged leftwardly as shown in Figure 2, pushing the seat 20 in a left hand direction and therefore compressing the return spring 6. When the latch is sufficiently retracted away from the striker plate 10, the door may be opened by pulling it towards the user as shown in Figure 7b) . Upon passing through the door, the user's hand naturally follows the profile of the edge of the door until he reaches the push handle with which he can pull the door closed as illustrated in Figure 7c) . The door latch mechanism of the present invention has many advantages over a conventional handle/latch mechanism, for example: 1. the latch mechanism of the present invention enables the user approaching the door to pull a cylindrical handle on the pull side of the door and push a rectangular push pad on the push side which is visually and ergonomically more intuitive than rotating a conventional handle or having to think about whether to push or pull. The design also assists in the continuous movement of, say, pushing the door open from one side, passing through and then pulling the door closed behind one. 2. The latch mechanism of the present invention is particularly easy to fit to a door since only a hole and a notch need to be cut into the side of the door to receive the door latch. 3. The latch mechanism of the present invention is relatively cheap and straight forward to manufacture since each of the main sections (push section 1, intermediate section 2 and pull section 3) can be cut from an extruded length of aluminium, simply sliced into sections of the appropriate thickness. This method allows for latch mechanisms of various lengths to be manufactured according to their application. Latch mechanisms for doors of different thicknesses can readily be implemented by using a packing pad to accommodate narrower doors than standard. It is envisaged that a locking mechanism could be easily incorporated into the latch mechanism of the present invention. The door latch mechanism of the present invention therefore provides a visually intuitive and ergonomically designed arrangement for opening and closing doors. The "vertical" orientation of the handles is more intuitive and easier to operate than conventional rotating handles and may be visually more pleasing. Clearly handles of different design could be attached to the push and pull sections 1,3 in order to fit in with surrounding decor. Changing the design of the handles may significantly alter the visual appearance of the handle/latch mechanism without affecting the operation thereof.

Claims: CLAIMS 1. A door latch mechanism mountable in a notch cut in the edge of a door so as to substantially surround said edge of the door, the latch mechanism comprising a handle on each of two opposing sides of a door latch wherein the latch is actuable by either handle, each handle being individually operable and independently communicating with the latch. 2. A door latch mechanism as claimed in claim 1 comprising a "push" section (1) , an intermediate section (2) and a "pull" section (3) , the push and pull sections being located, in use, on the push and pull sides of a door respectively and said latch being associated with said intermediate section to which the push and pull sections are operatively linked. 3. A door latch mechanism as claimed in claim 2 wherein said latch is mounted on a return spring, with each of said push and pull sections abutting the latch. 4. A door latch mechanism as claimed in claim 3 wherein compression of said spring causes said latch to retract away from a striker plate so as to enable a door to be opened, said compression being effected by either pushing said push section or pulling said pull section. 5. A door latch mechanism as claimed in any of claims 2 to 4 wherein said push section further comprises a push pad (4) . 6. A door latch mechanism as claimed in any of claims 2 to 5 wherein each of said sections comprises extruded metal, preferably aluminium. 7. A door latch mechanism as claimed in any of the preceding claims further comprising fixing means for fixing said mechanism to a door. 8. A door latch mechanism as claimed in any of the preceding claims further comprising a capping moulding (11,11') having a raised lip (12, 12') which, in use, conceals edges of a notch in a door in which the mechanism is mounted. 9. A door latch mechanism as claimed in any of claims 2 to 8 wherein a wear strip (14) is located intermediate the push section and the latch. 10. A door latch mechanism as claimed in any of the preceding claims wherein said handles are removeable and replaceable. 11. A door latch mechanism as claimed in any of the preceding claims further comprising a locking mechanism. 12. A door latch mechanism as claimed in any of the preceding claims which is suitable for use with any of the following: an outwardly opening door with a handle on the left hand side thereof; an outwardly opening door with a handle on the right hand side thereof; an inwardly opening door with a handle on the left hand side thereof; an inwardly opening door with a handle on the right hand side thereof. 13. A door latch mechanism as claimed in any of the preceding claims further comprising a packing pad which, in use, is placed intermediate the door and the latch mechanism in order to permit said latch mechanism to be used with a door of less than standard thickness. 14. A door latch mechanism substantially as described herein with reference to any appropriate combination of the accompanying drawings. 15. A method of manufacturing a door latch mechanism as described in any of claims 2 to 14 comprising the steps of extruding an extrusion having a cross-sectional shape suitable for said push section, slicing the extrusion into a -plurality of push sections of required thickness and similarly manufacturing the intermediate and pull sections from suitable extrusions.

Inventors: LOVERING TIMOTHY ARTHUR, LOVERING, TIMOTHY, ARTHUR
Applicants: LOVERING TIMOTHY ARTHUR, LOVERING, TIMOTHY, ARTHUR
Application year: 2001
Main classification: E05C1
IPC codes: E05B1, E05B17, E05B63, E05C1