BOLT HOUSING ATTACHMENT, ASSEMBLY AND FITTED BOLT HOUSING

Abstract: This invention relates to a bolt housing attachment (40), the bolt housing (30) having a bolt (34) which is movable in the direction of the bolt longitudinal axis (A-A), the attachment (40) having a fixing plate (42) and a lock plate (44), the lock plate (44) having a wall (48) adapted to lie alongside a part of the bolt (34) in its extended condition, the lock plate (44) being spaced from the fixing plate (42) in the direction of the said longitudinal axis. There is also provided an assembly comprising the bolt housing attachment (40) and a keeper (62); a method of increasing the security of a panel (10) in its frame (12) by utilising the bolt housing attachment (40); and a mortice bolt housing (30) fitted with an attachment (40).

Description: BOLT HOUSING ATTACHMENT, ASSEMBLY AND FITTED BOLT HOUSING FIELD OF THE INVENTION This invention relates to a bolt housing attachment, and in particular to an attachment for a bolt housing which is, or is to be, morticed into a panel (such bolt housings being referred to herein as "mortice bolt housings"). The invention also relates to an assembly of the attachment and a suitable keeper, and to a bolt housing fitted with such an attachment. The invention is likely to find its greatest utility in relation to mortice bolt housings for hinged panels such as doors which are intended to be secured relative to fixed frames, and the following description will therefore refer primarily to such use. However, the securement together of two panels which are both movable, and/or the securement of a slidable panel where appropriate, is not thereby excluded. DESCRIPTION OF THE PRIOR ART Bolt housings which are morticed into door panels are known. Typically, the housing carries a bolt which is movable by an actuator located within the housing, the bolt being movable between extended and retracted positions. The actuator may be operated by a handle or thumb turn (located upon the surface of the door), and/or by a lock mechanism located partially or fully within the housing, there being a keyhole communicating the housing with the surface of the door for insertion of a key into the lock mechanism. The bolt in its extended position projects from the housing (and from the morticed recess in the door) and is engageable with a keeper fitted to the frame. Conventional mortice bolt housings usually have a bolt which is substantially flat-ended, but some have (or also have) a latch with a chamferred edge, which latch can automatically engage the keeper and so retain the panel relative to the frame upon panel closure movement. It is a recognised problem of mortice bolt housings (and other types of bolt housings) that an intending intruder can force or jemmy the panel away from the frame to release the bolt and/or latch from its keeper. Once the panel has been forced in this way, subsequent opening of the panel is substantially unhindered by the bolt or latch. A bolt unit adapted to prevent or reduce the likelihood of such forcing is disclosed in my copending application WO97/01690, designed for surface mounting upon a panel. In that application there is disclosed a bolt unit having a housing from which a bolt can project, the housing carrying a receptor. The bolt has a two-stage movement, the first stage moving the bolt adjacent the receptor, the second stage moving the bolt into the receptor. When the bolt is within the receptor, the keeper is effectively coupled to the bolt such that forcing of the panel away from its frame is hindered or prevented. STATEMENT OF THE INVENTION The present invention seeks to provide a bolt housing attachment which is fitable to an existing or new mortice bolt housing so as to benefit from the "receptor" function of my copending application. In particular, the present invention provides an attachment which can be fitted to a mortice bolt housing, or to a panel in which the existing mortice bolt housing is located, to increase the resistance to unauthorised forcing of the panel away from the frame. According to the invention, therefore, there is provided a bolt housing attachment, the bolt housing having a bolt which is movable in the direction of the bolt longitudinal axis between a retracted position and an extended position, the attachment having a fixing plate and a lock plate, the lock plate having a wall adapted to lie alongside a part of the bolt in its extended condition, the lock plate being spaced from the fixing plate in the direction of the longitudinal axis. Preferably, the lock plate has at least one other wall adapted to lie alongside a part of the bolt in its extended position; preferably also said wall and said other wall are connected together. Desirably, there are four walls adapted to lie alongside a part of the bolt in its extended position, the four walls together defining a recess or aperture into or through which the part of the bolt passes as it moves to its extended position. Accordingly, the spacing of the lock plate from the fixing plate can be approximately the same as the throw of the bolt, the throw being defined as the distance between the retracted and extended positions of the bolt. Alternatively, the spacing can be less than the throw of the bolt, so that the extreme end of the bolt passes through the lock plate in the extended position of the bolt. In most cases, the extreme end of the bolt will be flush with the face of the bolt housing in its retracted position, so that the throw of the bolt is also the maximum distance by which the bolt can project from the face of the housing. Also, in use the face of the bolt housing will typically be flush with the edge surface of the panel, and so the throw of the bolt will typically correspond to the maximum distance by which the bolt can project from the edge surface of the panel. The fixing plate can preferably be secured directly to the housing, or alternatively indirectly secured relative to the housing by way of the edge surface of the panel. Since in the fitted condition the lock plate will be spaced from the edge surface of the panel by a distance no greater than the throw of the bolt, in its extended position a part of the bolt will enter, and perhaps project through, the lock plate. However, the spacing between the lock plate and the fixing plate permits the entry of a part of a keeper between the lock plate and the edge surface of the panel, the said part of the keeper having an aperture to receive a part of the bolt. Accordingly, when fully assembled and operational, the bolt can be extended to pass through the keeper aperture to lie alongside the attachment wall (or perhaps into or through the attachment lock plate aperture); attempted unauthorised forcing of the panel relative to the frame will thereafter be resisted by the attachment and the bolt linking the attachment to the keeper. According to another aspect of the invention therefore, there is provided an assembly comprising a bolt housing attachment and a keeper, the attachment and keeper being adapted for fitment to a panel and frame respectively, the bolt housing attachment having a fixing plate and an attachment lock plate, the plane of the attachment lock plate being spaced from the plane of the fixing plate, the keeper having a keeper lock plate which is of a lesser thickness than the spacing between the planes of the respective attachment plates, the keeper lock plate having a bolt-receiving aperture and the attachment lock plate having a wall alongside which a part of the bolt can lie. According to another aspect of the invention there is provided a method of increasing the security of a panel in its frame including the steps of {i} obtaining a bolt housing attachment as defined herein, {ii} securing the attachment either to a mortice bolt housing or to the edge surface of a panel adjacent the mortice bolt housing, with the attachment lock plate wall aligned with the bolt, {iii} locating a keeper upon the frame, the keeper having a keeper lock plate with a bolt-receiving aperture, the keeper being located so that its bolt-receiving aperture is aligned with the bolt when the panel is in its closed condition. Preferably the keeper lock plate is upstanding from a base of the keeper. Preferably also the keeper has an opening to receive the attachment lock plate. Usefully, the keeper has a wall defining the opening. Usefully also, the method of increasing the security of a panel in its frame includes the steps of rebating the frame to receive the wall and base of the keeper. Usefully, the attachment lock plate is joined to the fixing plate by a connecting part, the plane of the connecting part being substantially perpendicular to the plane of the fixing plate. Desirably, the attachment has a pair of fixing plates located to either side of the attachment lock plate, the fixing plates being joined to the lock plate by respective connecting parts. As above indicated, and notwithstanding the title of "bolt housing attachment", the attachment can be adapted for fitment to the edge of the panel adjacent the bolt housing, in which case it is indirectly secured relative to the housing by way of the panel. In such embodiments the fixing plate(s) may include openings to receive bolts or screws; preferably the openings are countersunk. Preferably, however, the attachment is adapted for securement directly to the bolt housing, either by way of screws or bolts as above, or by welding or the like. Preferably, the bolt housing also includes a latch; preferably also the, or one of the, fixing plate(s) includes an aperture through which a part of the latch can pass. Usefully, both the bolt housing attachment and the keeper are of metal. According to yet another feature of the invention, there is provided a mortice bolt housing fitted with an attachment as herein defined. BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described, by way of example, with reference to the accompanying drawings, in which: - Fig.l is a view of a door panel hingedly mounted in a fixed frame; Fig.2 is a side view of part of a door and frame, showing a mortice bolt housing fitted with a lock attachment according to the invention; Fig.3 is a perspective view of the bolt housing attachment of Fig.2, and Fig.4 is a perspective view of a keeper as used with the bolt housing attachment of Figs.2 and 3. DESCRIPTION OF THE PREFERRED EMBODIMENTS The panel 10, in this embodiment a door, is located relative to the frame 12 by way of hinges 14 in known fashion. The frame 12 is secured to the wall 16, also in known fashion. The panel 10 carries a mortice bolt housing which is morticed into the door 10 adjacent its edge surface 20, and so is not visible in Fig.l. In this embodiment the mortice bolt housing 30 has both a latch and a bolt, the latch being operable by way of handle 22, and the bolt being operable by a key-operated mechanism located within the housing and engageable by a key inserted into keyhole 24. In known fashion, the keyhole 24 is provided in an escutcheon 26 which engages the surface of the door 10. In Fig.2, the mortice bolt housing 30 is shown in dotted outline (it is not visible since it is morticed into the door). In known fashion, the face 32 of the housing 30 lies substantially flush with the edge surface 20 of the lock edge of the door 10 (the lock edge being defined herein as the edge opposed to the hinged edge). The bolt 34 can project from the housing 30, and also from the edge surface 20, by a maximum distance t; as shown the bolt 34 is in its extended position, i.e. having its maximum extension or projection from the housing 30. The distance "t" represents the "throw" of the bolt 34, which is determined by the structure of the components within the housing 30, in known fashion. Secured to the edge surface 32 of the housing 30 is a lock attachment 40, the lock attachment having a pair of fixing plates 42a and 42b, and a lock plate 44 (as better seen in Fig.4). The fixing plates 42a,b have bolt or screw holes 46 (preferably countersunk) by which the fixing plates 42a,b (and thus the attachment 40) is secured to the edge surface 20. In other embodiments the fixing plates may be secured directly to the housing 30, perhaps by way of screws or bolts, or perhaps by welding. The lock plate 44 has an aperture 50 formed by a wall 48 and three other connected walls (not numbered). The aperture 50 corresponds in size, shape and alignment (when fitted as in Fig.2) to the bolt 34. The fixing plate 42b has an aperture 52 corresponding in size, shape and alignment (when fitted as in Fig.2) to the latch 54. In other embodiments there is only one fixing plate connected to the lock plate in cantilever, though such embodiments are not preferred. In practice, the fixing plates will typically be above and below the lock plate in the orientation of use as shown in Fig.2, taking advantage of the large vertical dimension of the door and not relying upon fixation to the small horizontal dimension of the edge surface 20; however, in thicker doors the fixing plate or plates can alternatively or additionally be located horizontally spaced from the fixing plate. The lock plate 44 and fixing plates 42a,b are interconnected by connecting parts 56, which in this embodiment lie substantially parallel to the longitudinal axis A-A of the bolt 34. The plane of the lock plate 44 is spaced from the plane of the fixing plates 42a,b by a distance s which is less than the throw t of the bolt 34, so that as shown in Fig.2 when the bolt 34 is moved to its extended position it enters the aperture 50 in the lock plate 44. When the door is in the closed condition as shown in Fig.2, keeper lock plate 60 is located between the attachment lock plate 44 and the edge surface 20. As better seen in Fig.3, the keeper lock plate 60 is an integral part of the keeper 62, and upstands from base 64. The keeper 62 has an opening 66 into which the lock plate 44 and connecting parts 56 of the attachment 40 can locate. The keeper 62 has a wall 70 which surrounds the opening 66; the wall 70 is connected to the base 64 to provide structural strength to the keeper. It will be understood that the latch 54 is not an essential requirement of the bolt housing, but is fitted to many of the presently available mortice bolt housings. Thus, it is desirable that the lock attachment and keeper can accommodate such latch. Accordingly, as above indicated the fixing plate 42b has an opening 52 through which the latch can project into latching engagement with keeper aperture 72. The latch 54 is chamferred in known fashion, and as the door is moved to its closed position the chamferred edge (not seen) rides up the keeper surface 74, which acts to press the latch 54 back into the housing 30, the latch springing from the housing as it becomes aligned with the aperture 72, in known fashion. In other embodiments of the attachment the fixing plate 42b can terminate short of the latch, so that an aperture is not required therefor; however, it is preferred that the fixing plate extend beyond the latch for mortice bolt housings for which a latch is fitted, so as to provide increased strength for the attachment (since in practice the spacing between the latch and the bolt is often small - perhaps 2 cm or less) . As described, the fixing plate(s) can be secured by welding directly to the bolt housing, and such securement is likely to be most suitable for fitment as original equipment. The fixing plate(s) can alternatively be secured to a new or existing housing by screws or bolts, notwithstanding that this will require the provision of suitable threaded holes in the housing. Alternatively, the fixing plate(s) can extend beyond the housing so as to be securable directly to the edge surface of the panel, as in the embodiment of Fig.2). it will be appreciated that as compared to prior art lock arrangements in which a fairly small recess is required in the frame (corresponding to the size and throw of the bolt 34 ) , with a lock attachment according to the invention a larger recess will be required to accommodate the enlarged keeper (and in particular the base 64 and wall 70). However, it is believed that this additional material removal is of little or no detriment to the strength of the frame, the removed material being compensated for by the enhanced strength of the keeper. The keeper 62 has keeper fixing plates 76 with countersunk screw or bolt holes 78, by way of which it may be secured to the frame 12. The bolts or screws (not shown) which are used to secure the keeper 62 to the frame 12 may be elongated so as to pass completely through the frame 12 and into the wall 16, offering considerable resistance against movement of the keeper 62. The keeper lock plate 60 has a number of ( in this embodiment four) connected walls 82 which together define an aperture 80 through which the bolt 34 can pass, in known fashion. To operate the assembled bolt housing, attachment and keeper, once the parts have been fitted as above described, the door 10 is moved to its closed condition. In this condition, the keeper lock plate aperture 80 is aligned with the attachment lock plate aperture 50 and with the path of movement of the bolt 34. The bolt 34 is then moved to its extended position (Fig.2), passing through the keeper plate aperture 80 and also through the attachment lock plate aperture 50. Thereafter, the resistance to movement of the door 10 (as by a jemmy) will be considerably increased over a prior art mortice bolt housing and keeper arrangement. Since the fixing plate(s) (particularly for an attachment for an existing bolt housing) must be accommodated in the gap between the edge surface 20 and the frame 12, it is necessary that this plate (these plates) be of small dimension (in the direction of the axis A-A); however, it is expected that a (metallic) fixing plate of greater than 2 mm thickness could provide adequate strength for the vast majority of requirements, whilst a fixing plate of up to 5 mm thickness should be able to be accommodated in the gap between the (door) edge surface 20 and frame 12 in a large proportion of cases. Alternatively, however, if the gap is too small to accommodate the fixing plate(s), the frame can be rebated as necessary. Or, the edge surface can be rebated to receive the fixing plate(s), so that only the lock plate and connecting parts project beyond the edge surface, which parts can be accommodated in a suitable rebate created in the frame. Most presently-available mortice bolt housings have a bolt throw of at least 14 mm, though some have a throw of only 12 mm; new legislation in the European Union for example however seeks to set a standard of 20 mm or 25 mm for the throw of a bolt of a mortice bolt housing. The attachment is intended to be suitable for use with many or all of the available mortice bolt housings, and even with the smallest of the above throws it is possible to accommodate a keeper lock plate of 5 mm thickness between the edge surface and the attachment lock plate, and still be able to receive the bolt in an aperture of the attachment lock plate. Clearly, with a mortice bolt housing providing a longer throw the ability to achieve greater clearance between the relatively moving parts of the keeper and lock attachment will be increased without impairing the strength thereof. Whilst the mortice bolt housing has been described as being in the door or panel and the keeper in the frame (which is the normal arrangement), it will be understood that the reversal of these positions is also possible. It will also be understood that the invention could be utilised with other panels such as windows, and in particular with hollow profile windows made of plastics materials which are known to incorporate mortice bolt housings and/or shoot bolts as part of their locking mechanism. In the embodiment shown in the drawings, the throw t of the bolt 34 is such that the extreme end of the bolt passes through the aperture 50 in its extended position (Fig.2). However, in other embodiments the throw of the bolt is smaller, or the spacing between the lock plate and the fixing plate is increased, so that the end of the bolt does not pass through the lock plate. In such embodiments, it would be possible for the lock plate to have a recess for receiving the end of the bolt, rather than an aperture therethrough. Also, it will be appreciated that when an uanuthorised attempt is made to jemmy the panel 10 away from the frame 12, the panel 10 is usually forced outwardly of the paper as viewed in Fig.2. Under such jemmying force, it is only the wall 48 of the aperture 50 which is engaged by the bolt (as the keeper aperture 80 seeks to retain the bolt against the jemmying force); accordingly, the lock plate could comprise only the wall 48 and still resist such jemmying. However, if there is the chance of jemmying the panel 10 upwardly and/or downwardly (as viewed in Fig.2), then alternative and/or additional lock plate walls will be required, the additional walls preferably being connected to the wall 48. Clearly, notwithstanding that an aperture or recess having four connected walls (such as aperture 50) will not always be required, such an arrangement is preferred as this provides additional strength and an aesthetically pleasing product. In addition, because the attachment lock plate 44 locates behind the keeper lock plate 60 when the panel is in its closed condition, the jemmying of the panel so as to increase the gap between the panel edge surface 20 and the frame 12 (as when an attempt is made to release the bolt from the keeper lock plate aperture 80) will be resisted by engagement between the attachment lock plate 44 and the keeper lock plate 60. In another embodiment the lock plate attachment can have a cover plate secured thereto so as to conceal the keeper lock plate when in use. Assuming that in the embodiment of Fig.2 the panel 10 opened towards the viewer, the cover plate could be fitted so as to span and conceal the area between the connecting parts 56, so as to obscure the keeper lock plate 60 and much of the bolt 34. Such a cover plate would make the assembly more aesthetically pleasing, and also prevent or hinder access to the keeper lock plate and bolt when the panel was in the closed condition, which access might be used in an attempt to effect unauthorised opening of the panel .

Claims: CLAIMS 1. A bolt housing attachment (40), the bolt housing (30) being a mortice bolt housing having a bolt (34) which is movable in the direction of the bolt longitudinal axis (A-A) between a retracted position and an extended position, the attachment having a fixing plate (42) and a lock plate (44), the lock plate having a wall (48) adapted to lie alongside a part of the bolt in its extended condition, the lock plate being spaced from the fixing plate in the direction of the said longitudinal axis. 2. An attachment according to claim 1 in which the lock plate has at least one other surface adapted to lie alongside a part of the bolt in its extended position. 3. An attachment according to claim 1 in which there are four lock plate surfaces adapted to lie alongside a part of the bolt (34) in its extended position, the four lock plate surfaces together defining a recess or aperture (50) in the lock plate (44) into or through which the part of the bolt moves as it is extended. 4. An attachment according to claim 1 in which the attachment lock plate (44) is joined to the fixing plate (42) by one or more connecting parts (56), the plane of the connecting part(s) being substantially perpendicular to the plane of the fixing plate. 5. An attachment according to claim 1 in which the attachment (40) has a pair of fixing plates (42a, 42b), one fixing plate being located to either side of the attachment lock plate (44), the fixing plates being joined to the lock plate by respective connecting parts (56). . An assembly comprising a bolt housing attachment (40) according to claim 1 and a keeper ( 62 ) , one of the attachment and keeper being adapted for fitment to a panel (10) and the other of the attachment and keeper being adapted for fitment to a frame (12), the bolt housing attachment having an attachment fixing plate (42) and an attachment lock plate (44), the plane of the attachment lock plate being spaced from the plane of the attachment fixing plate by a spacing (s), the keeper having a keeper lock plate (60) which is of a lesser thickness than the spacing (s), the keeper lock plate having a number of connected walls which together define an aperture (80) through which a part of the bolt (34) can pass, the attachment lock plate wall (48) being substantially aligned with one of the walls of the aperture. 7. An assembly according to claim 6 in which the keeper lock plate (60) is upstanding from a base (64) of the keeper. 8. An assembly according to claim 6 in which the keeper has an opening (66) to receive the attachment lock plate (44), and a wall (70) defining the opening. 9. A method of increasing the security of a panel (10) in its frame (12) including the steps of {i} obtaining a bolt housing attachment (40) according to claim 1, {ii} securing the attachment either to a mortice bolt housing (30) or to the edge surface (20) of the panel adjacent the mortice bolt housing, with the attachment lock plate wall (48) aligned with the path of movement of the bolt (34), {iii} locating a keeper (62) upon the frame (12), the keeper having a keeper lock plate (60) with a bolt-receiving aperture, the keeper being located so that its bolt-receiving aperture is aligned with the part of movement of the bolt when the panel is in its closed condition. 0. A mortice bolt housing (30) fitted with an attachment (40) according to claim 1.

Inventors: KIBBLE ANTHONY WILFRED, KIBBLE, ANTHONY, WILFRED
Applicants: KIBBLE ANTHONY W, KIBBLE, ANTHONY, WILFRED
Application year: 1999
Main classification: E05B17
IPC codes: E05B15, E05B17