The invention relates to handles, and particularly to high security handles for doors. High security handles for doors are well known, but are generally produced from cast stainless steel, which makes the handles relatively expensive for certain segments of the market.

Other handles are produced from solid die cast aluminium, which is then machined, and although this is a reasonable product, it is not as secure as handles produced from cast stainless steel.

The invention seeks to provide a handle which is not as expensive as a cast stainless steel handles, but is more secure than a solid die cast aluminium handle. The invention provides a handle comprising a body manufactured from a first material, reinforced with a back plate manufactured from a second, more robust material.

In a preferred embodiment, the body is manufactured from die cast aluminium and the back plate is manufactured from steel.

However, the body may be manufactured from some other material which is less robust than steel, for example plastics material.

Preferably the steel plate reinforcement is deep drawn to give good protection, for example to a lock cylinder attached to the handle.

For example, the steel back plate may have a region which is deep drawn to project away from the plane of the back plate, providing a shroud which in use will surround a lock cylinder. Tapped insert bushes may be used to fix the components together.

Preferably the handle incorporates an integral spring loaded cassette, biasing an operating lever of the handles into a rest position. The body may be provided with a hollowed out region, for example by appropriate die casting, to provide room to accommodate the spring loaded cassette.

By way of example, a specific embodiment of the invention will now be described, with reference to the accompanying drawings, in which: Figure 1 is a front elevation of an embodiment of a high security door handle according to the invention; Figure 2 is a perspective view of the handle, to a reduced scale;

Figure 3 is a cross sectional view of the handles, taken on line A-A of Figure 1 ;

Figure 4 is a front elevation of a handle assembly comprising an inner door handle and an outer door handle, which in use will be connected respectively to the inside and outside of a door, only the outer door handle being visible in Figure 4;

Figure 5 is a side elevation of the assembly of Figure 4, showing both the inner and outer door handles;

Figure 6 is a cross sectional view on line B-B of Figure 4;

Figure 7 is an exploded perspective view of the handle according to this embodiment; and Figures 8a and 8b illustrate the operation of a return spring cassette of the handle.

The handle shown in Figures 1 , 2, 3 and 7 comprises an aluminium die cast body 10 which forms the front face of the handle, and a deep drawn steel reinforcement back plate 1 1. Fitted to the body is an operating lever 1 1a which is biased into the rest or start position shown in the Figures by a spring cassette best shown in Figures 7, 8a and 8b.

The lever 1 1a has a boss 13 which is pivotally connected to the body 10 by a fixing insert 14 which passes through an aperture 15 in the body 10 then through a washer 16, and then into a shaped socket 17 in the boss 13.

The fixing insert 14 is shaped to engage in the socket 17 such that the boss 13 and insert 14 rotate as one. The insert 14 is attached to the lever 1 1a by a fastener 18.

The return spring cassette comprises two blocks 19 and each block receives within a pair of bores respective return compression springs 20. As best seen in Figures 8a and 8b, the insert 14 has flats 14a thereon. In the rest or start position shown in Figure 8a, the blocks 19 abut against the flats 14a, under the action of the springs 20, and this gently holds the handle in the rest or start position. When the handle is depressed to operate the assembly the insert 14 rotates to the position as shown in Figure 8b, and the blocks 19 are forced apart against the action of the springs 20. This means that when the handle is released the action of the spring loaded blocks 19 causes the insert 14 to rotate in the opposite direction until the handle is returned to its rest or start position.

In use, a pair of complementary handles will be fitted on the inside and outside of the door, as shown in Figures 4, 5 and 6. The assembly will incorporate a locking cylinder 21.

As best shown in Figure 7, the plate 1 1 is deep drawn out at 22 to provide secure protection for the locking cylinder 21 , reducing the risk that an intruder could drill out the locking cylinder. Deep drawn out portion 22 affords protection against cylinder manipulation attack. Without the shrouding effect of the deep drawn portion 22, an intruder could seek to apply lateral mechanical force to the cylinder 21 , for example using a pair of mole grips, with the intention of snapping the lock cylinder in order to remove it from the locking assembly. The very robust steel shroud provided by the portion 22 makes such an attack much more difficult. The cylinder is also protected by a shroud 23 and an anti-drill cover 24.

The back plate 1 1 is connected to the body 10 by tapped and drilled fixing bosses 25 and by self tapping screws 26.

By manufacturing the main body 10 from die cast aluminium, the cost is reduced and it is also possible to cast a shape which leaves room to accommodate the spring return cassette. However the deep drawn steel back plate 1 1 increases the security of the handle. The fixing bosses 25 have a top hat section and clamp down onto counter bore details 28 in the steel back plate 1 1 thus locking the plate in place. The bosses 25 are internally tapped to receive through fixing machine screws which in use fix the handle to the door. This has the effect of clamping the handle rigidly to the main slab of the door. In addition, forward elements 25a of the bosses 25 that project through the counterbore detail 28 of the back plate 1 1 are externally threaded to be received in a correspondingly tapped part 25b of the faceplate 10. Thus, with the bosses 25 secured to the faceplate 10, the back plate 1 1 and face plate 10 are held firmly together. The advantageous use of internal and external threads on the bosses 25 allows for a single part to be used to secure the back plate 1 1 to the faceplate 10 and to secure the handle to the door. The countersunk screws 26 bridge the weakest section of the handle, namely the lever assembly area, to ensure high strength throughout. This fixing method ensures that the body and the back plate act as one unit and has been found to provide high resistance to repeated attacks in security tests. It can therefore be predicted that the handle will provide high resistance to attack in a real life situation.

Designing the reinforcing of the handle with a steel plate located at the rear of the handle means that the face plate can be hollowed out where strength is not required. This in turn enables a cavity to be introduced to accommodate the spring return cassette unit.

The use of die cast aluminium means that different finishes can be provided, for example with aesthetic cover plates, powder coatings, etc.

The design also enables a different choice of operating levers to be offered with the same basic body and back plate construction.

Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.