This invention relates to a viewing assembly of the type which may, for example, be inserted into a door, to allow a person within a room or a residence to see people at the door.

A viewing assembly of this general type is disclosed in United States Patent No. 4,763,444. In.. that known assembly, there is mounted a glass panel, which is held between inner and outer bezels. Mounted in the outer bezel are a number of mirror surfaces, including a mirror located along the upper edge of the glass panel and angled downwards, allowing the field of vision of a person viewing from the inside of the assembly to extend below the assembly. However, a disadvantage of this arrangement is that the image seen by a user through the glass panel, and that seen reflected in the upper mirror surface, are directly adjacent.

According to a first aspect of the present invention, there is provided a viewing assembly comprising a piece of transparent material held between inner and outer retaining means, and having a reflective surface located on the outer side of the transparent material, wherein the inner retaining means is provided with a longitudinally extending portion, the arrangement being such that the assembly can be inserted into a door with the reflective surface angled downwardly and having its lower edge extending substantially horizontally, while the longitudinally extending portion extends generally horizontally such that, for a user on the inside of the assembly, it defines the boundary between an image seen in the reflective surface and an image seen through the transparent material alone. The assembly shown in US-4,763,444 has a flap pivotably mounted to the inside thereof. The flap is

provided with a narrow slit extending therethrough. The slit is angled such that the top and bottom surfaces thereof are horizontal, allowing a user to see through the slit, only when the flap has been lifted slightly. However, this slit does not provide the user with a field of vision which extends very far in a vertical direction.

According to a second aspect of the present invention, there is provided a viewing assembly for a door, having a flap pivotably mounted on the inside thereof, wherein the flap has a viewing slot located therein and, adjacent the slot, a protrusion angled relative to the flap such that, when the flap is in its normal closed position, the protrusion is generally at the same horizontal level as the slot, but, when the flap is pivoted inwardly, the protrusion is generally not at the same horizontal level as the slot. The dimensions and positioning of the protrusion are chosen such that it obscures the line of vision through the slot when the flap is in the closed vertical position, but opens up the line of vision when the flap is pivoted to a partly open position. Preferably, the protrusion is provided on the outer face of the flap, i.e. the face located on the underside when the flap is pivoted inwardly, and is adjacent the lower edge of the slot and angled generally upwards.

The assembly of US-4,763,444 is provided with a flap on the side thereof intended to be positioned at the inside of the room or residence in which the assembly is used. When this flap is lifted, to allow the user to see through the assembly, light from the room in which the user is located can fall on the glass panel. The glass panel is coated with a film which limits transmission of light from the inside of the assembly to the outside. The purpose of this film is to allow a user of the assembly to see a person located

outside the room whilst limiting the ability of the person outside the room to see the user of the assembly. However, whatever film is used to coat the glass, this aim is more likely to be achieved if the amount of light falling on the outer surface of the glass is greater than that falling on the inner surface of the glass.

According to a third aspect of the present invention, there is provided a viewing assembly for doors comprising a piece of transparent material mounted therein and coated with a film which reduces the amount of light transmitted from the inside of the assembly to the outside relative to the amount of light transmitted from the outside of the assembly to the inside, the assembly further comprising a flap pivotably mounted to the inside of the assembly and a plate having an aperture therein, the area of the aperture being substantially less than the surface area of the transparent material. In a preferred embodiment, the transparent material may be held between inner and outer retaining means, each retaining means having an opening therein of substantially the same dimensions as those of the sheet of transparent material. The plate may then be mounted to the inner surface of the inner retaining means or, alternatively, may be insertable in the opening within the inner retaining means. The aperture may either be formed in the plate, or may be defined by the plate and the inner retaining means. The assembly of US-4,763,444 comprises a pieee of glass mounted in a frame, the frame being held between inner and outer bezels, which are screwed to the door in which the assembly is to be mounted. There are described two ways in which this can be carried out. Firstly, it is mentioned that a single screw, on each side of the assembly, can pass through the solid

material of the door from the inner bezel to the outer bezel. However, in the event of fire, this method allows transmission of heat via the screw, and thus is undesirable. Secondly, it is mentioned that the inner and outer bezel can each be screwed separately to the door. This has the disadvantage that the outer bezel must be screwed to the door from the outside of the door, and, although the specification discloses that the heads of the screws be covered by plates, this is a potential disadvantage as there remains the possibility that the screws could be removed by unauthorised persons.

According to a fourth aspect of the present invention, there is provided a viewing assembly for doors, comprising a piece of transparent material held in a frame, the frame being held between inner and outer retaining means, wherein the outer retaining means is fixed to the frame, the inner retaining means is fixed to the frame, and the inner retaining means may then be fixed to a door. In the preferred embodiment, the outer retaining means is fixed to the frame by means of horizontal screws lying in the plane of the door; the inner retaining means is fixed to the frame by means of horizontal screws perpendicular to the plane of the door; and the inner retaining means is provided with a panel pin hole or screw threaded portion provided at an acute angle to the plane of the door. In this embodiment, the outer retaining means is screwed to the frame before insertion of the assembly into the door, and the heads of the screws are not accessible when the assembly has been inserted into the door.

The assembly disclosed in US-4,763,444 comprises a piece of glass held in a frame. The frame is made up of two pieces of non-combustible fibre board, each having a horizontally extending portion and two side

portions of half the height of the piece of glass.

According to a fifth aspect of the present invention, there is provided a viewing assembly for doors, comprising a sheet of transparent material held in a frame, wherein the frame is made up from two slotted side pieces, the dimensions of the slots being adapted to receive the transparent material; a substantially planar upper member, fixed to the side pieces; and a horizontally extending lower member, fixed to the side pieces, the lower member being generally planar but having a recess in the upper surface thereof immediately adjacent the sheet of transparent material, and intumescent material being located in the recess. For a better understanding of the present invention, and to show how the same may be brought, into effect, reference will now be made, by way of example only, to the accompanying drawings in which:-

Figure 1 is an exploded view of the assembly according to the present invention;

Figure 2 is a view on arrow A in Figure 1 ; Figure 3 is a view on arrow B in Figure 1 ; Figure 4a and 4b are cross-sectional views of a flap which forms part of the assembly; and Figure 5 is a view of an alternative inner retaining means which may be used to replace that shown in Figure 1.

The assembly comprises a sheet of glass 1 , to the outer surface 2 of which there is applied a material which reduces the transmission of light from the inside of the assembly to the outside thereof. The glass is held in slots 3, 4 in respective side pieces 5, 6 of a frame, which also includes an upper member 7 and a lower member 8. The upper and lower members are fixed to the side portions by means of pins 9a-9h. The frame is provided with screw holes 10 in the side portions,

and screws 11a, 11b to be inserted therein. The lower member 8 is provided with a groove 12, positioned to lie beneath the glass 1 , in order to allow audio communication from one side of the assembly to the other. The groove also contains intumescent material which, in the event of fire, is intended to fill the groove and prevent the passage of smoke from one side - of the assembly to the other. The side portions 5, 6 further have screw holes 13a, 13b on their inner faces. The outer retaining means 20 comprises a frame having screw holes 21a, 21b. During manufacture of the assembly, the screws 11a, 11b pass through holes 21a, 21b, in order to fix the outer retaining means to the frame. Mirrors 22, 23, 24 are provided on the outer retaining means, in order to allow the field of vision of a user of the assembly to be widened. Mirror 22 is located on surface 25 of the outer retaining means; mirror 24 is located on surface 26 of the outer retaining means; and mirror 23 is located substantially horizontally, at an acute angle to the horizontal -plane, on the inside upper surface of the outer retaining means. A flange 27 is provided around the periphery of the outer retaining means.

The inner retaining means 30 comprises a casing 31 having an aperture 32 located therein. A horizontal bar 33 extends across the aperture 32. The casing 31 has holes 34 in its side members. The inner retaining means 30 can be fixed to the side portions 5,6 of the frame by pins (not shown) passing through the holes 34. The casing is further provided with a screw threaded portion 35 located at an acute angle to the plane of the door, by means of which the assembly can be screwed to a door with a screw 36. Alternatively, the assembly may be secured to the door by means of a panel pin passing through an acutely angled hole. The pin may then be inserted in such a way that it can be removed

only with a special tool. The bar 33 divides the aperture 32 into an upper portion 37 and a lower portion 38.

A plate 40 has screw holes 41a, 41b and an aperture 42 located therein. At the upper edge of the plate 40 are provided pin retaining means 43a, 43b. In use, the inner retaining means 30 is mounted to the frame by means of screws 44 which pass through holes 13 in the side portions of the frame. The screws 44 also pass through caps 45 which are located around the holes 41a,41b and which prevent the removal of the screws. Located at the inside of the assembly is a flap 50, which is pivotably mounted to the plate 40 by means of pins 51a, 51b which pass through holes in the pin retaining means 43a, 43b. On the outer face 54 of the flap is an angled protrusion 52 which extends outwardly and upwardly from the lower edge of a slot 53 in the flap. When the flap 50 is in its normal vertical closed position, the protrusion 52 serves to obscure the view both ways through the slot 53, as shown in Figure 4a. However, when the flap is pivoted to a position similar to that shown in Figure 4b, the protrusion is pivoted into an essentially horizontal position, and a user of the assembly can see through the slot 53 but without being observed by a person on the outside of the door.

In an alternative embodiment, the protrusion may be provided on the inner face of the flap adjacent the upper edge of the slot and angled generally downwardly. Figure 5 shows an alternative inner retaining means 130 and insert 140, which may be used to replace the inner retaining means 30 and plate 40 shown in Figure 1. The inner retaining means 130 has a casing 131 provided with an aperture 132, having a horizontal bar 133 positioned therein. The casing 131 is provided with a screw threaded portion 135, by means of which

the inner retaining means can be fixed to a door, and screw holes 141a, 141b, by means of which the inner retaining means can be screwed to the side portions 5, 6 of the frame. Again, the inner retaining means may alternatively be pinned to the door by a panel pin passing through a hole at an acute angle to the plane of the door. The casing is further provided with pin . retaining means 143a, 143b. An insert 140 is sized to fit within an aperture 137 in the inner surface of the casing 131, and is provided with pegs 145a-145d, by means of which it may be retained securely within the aperture 137. The inner retaining means 130 and the insert 140 are equivalent, when combined, to the inner retaining means 30 and the plate 40 shown in Figure 1. Thus, to manufacture the assembly, and position it in a door, the lower member 8 is fixed to the side portions 5,6 of the frame, the sheet of glass 1 is lowered into the slots 3, 4, and the upper member 7 is then fixed to the side portions 5, 6. The outer retaining means 20 is then screwed to the frame by means of screws 11a, 11b, and the frame is placed from the outside of the door into an aperture which has already been cut, such that the flange 27 rests on the outside of the door. The assembly is then fixed firmly to the door by means of the screw 36, and the inner retaining means is fixed to ^" the frame by means of screws 44.

In use of the assembly, the provision of the plate 40 or insert 140 limits the amount of light falling on the glass 1 from the inside. This means that it is very difficult for a person on the outside of the assembly to see into the room or residence in which it is used. In addition, a further result is that the plate 40 or insert 140 reduces stray reflections from the glass, allowing the user to see out more easily.

A user of the assembly inside a room which has the

assembly in a door thereof has his field of vision extended along the walls of the room by means of the mirrors 22,24. A view straight out through the glass is obtained through the lower part 38 of the aperture 32, and the mirror 23 can be seen through the upper part 37 of this aperture, allowing the user to see down towards the ground, including vertically downwardly next to the door. The bar 33 serves to provide a clearly identifiable boundary between the view seen through the mirror 23 and that straight through the glass.

Although the invention has been described herein with reference to one specific embodiment thereof, it will of course be appreciated that modifications and alternatives falling within the scope of the appended claims also form part of the invention. For example, although the invention has been described with reference to its insertion in a door, it could of course be used in any space divider such as a door, an internal wall or an external wall.