GB2363625A - Shoot bolt mechanism - Google Patents

Abstract

A locking bar arrangement for mounting on an end face of a window or door having a groove therein, comprises at least one locking bar (2a, 2b). Each locking bar (2a, 2b) comprises a force transmitting section (3) for transmitting force from a mechanism (1), and a bolt section (4) coupled to the force transmitting section (3). One section moves in a first plane inside the groove in the frame and the other section moves in a second plane located above the first plane, such that the ends of the two sections (3,4) of the locking bar overlap. Means are provided to adjustably couple the two sections of the locking bar to vary the length of the locking bar.

Description

2363625 Shoot Bolt Mechanism Shoot bolt mechanisms are used in doors and

windows to achieve a secure fastening of the door or window and generally include a drive mechanism which operates a shoot bolt by rotation of a handle The shoot bolt engages the side of the frame adjacent the mechanism Most shoot bolt mechanisms also include two locking bars and the drive mechanism also transmits rotation of the handle into translational movement in opposite directions of the locking bars Movement of the locking bars is perpendicular to the movement of the shoot bolt Rotation of the handle in one direction causes the locking bars to extend and engage in shoot bolt keeps on opposite ends or sides of the frame of the door or window Rotation of the handle in the opposite direction retracts the bolts, unlocking the window or door The shoot bolt mechanism thereby achieves locking at both top and bottom or opposite sides by the operation of a single handle Some mechanisms, also known as espagnolet mechanisms, only employ the two locking bars, and the present invention is also applicable to these types of mechanisms.

The locking bars are usually accommodated in shallow grooves in the frame, and the end portions of the locking bars project beyond guide members which are fixed at the corners of the window or door frame, for engagement with the keeps when the mechanism is in the locked position In the open position of the mechanism, the ends of the locking bars are retracted into the guide members.

Shoot bolt mechanisms often include drive members which move in opposite directions inside the drive mechanism and are coupled to the locking bars This is usually by means of projections on the drive bars which mate with holes in the locking bars A cover plate is then fixed in position over the couplings Before connecting the locking bars to the mechanism and attaching the cover plate, the locking bars are cut to the correct length, depending on the size of the window or door The length must be cut accurately If the locking bars are too short, they will not engage fully in the keeps and the security of the device will be reduced If the locking bars are too long, the mechanism will not fully lock and again, security will be reduced Cutting the locking bars to the correct length is therefore difficult, time consuming, and if a locking bar is cut too short, the part is wasted It is therefore desirable that locking bars be provided which are easily adjustable in length.

In some widely available commercial shoot bolt mechanisms, the drive members extend out from the mechanism and include end sections having rectangular recesses with internal teeth for mating with the end of a locking bar having external teeth The locking bar has external teeth along a large portion of its length and must still be cut to the correct length before slotting into engagement with the end of the drive member An example of such a coupling is shown in GB-A-2264529.

GB-A-2313617 discloses a shoot bolt mechanism designed for easy assembly With the mechanism in the closed position, the inner ends of the locking bars are positioned on projections on the drive bars The mechanism is then moved into the open position and the locking bars retract such that their inner ends are contained by retaining elements A cover plate is then fixed over the mechanism.

The locking bars also include means for adjusting their length Each locking bar comprises a first section which engages with the mechanism and a second section for engaging with the keep An end portion of the first section has a longitudinal slot having internal teeth A generally rectangular clamping piece having external teeth, fits inside the slot and its external teeth mate with the internal teeth in the slot The clamping piece may be removed and moved to different positions along the slot.

The clamping piece is attached, by means of a screw, to the second section of the locking bar On releasing the screw, the clamping piece may be moved to different positions along the slot, adjusting the total length of the locking bar This form of coupling has the disadvantage that the small parts, in particular the clamping piece and the screw are liable to be lost.

EP-A-0863283 discloses a mechanism designed to be independent of the depth of the groove in the frame, but which also discloses a means for adjusting the length of the locking bars In the mechanism of EP-A-0863283, a force transmitting section of each locking bar extends from the mechanism along the surface of the groove A bolt section runs in a plane above the plane in which the force transmitting section moves, ie outside the groove The coupling between the two sections is achieved by means of an upwardly projecting section of the force transmitting section having internal teeth, which mates with external teeth on the bolt section The bolt section has external teeth along a substantial portion of its length such that the coupling may be made at different positions to adjust the total length of the locking bar As the two sections move in different planes, they can overlap, and there is no need to cut the bolt section to the correct length An alternative reverse arrangement is also proposed wherein the bolt section has internal teeth and the force transmitting section has an extended portion having external teeth In the mechanism of EP-A-0863283, the coupling between the two sections of locking bar creates a weak point If a large force is exerted on the end of the locking bar, which may happen if a attempt is made to lock the mechanism when the bolts are not properly aligned with the keeps, the locking bar tends to buckle and the coupling may become disengaged.

According to the present invention, a locking bar arrangement for mounting on an end face of a window or door, the end face having a groove therein, comprises at least one locking bar comprising a force transmitting section for transmitting force from a mechanism, and a bolt section coupled to the force transmitting section, wherein one section moves in a first plane inside the groove in the frame and the other section moves in a second plane located above the first plane, such that the ends of the two sections of the locking bar overlap, wherein means are provided to adjustably couple the two sections of the locking bar to vary the length of the locking bar.

In the present invention, one section of the locking bar moves inside the groove in the frame Preferably, the other section moves in a plane which is also inside the groove, or substantially parallel with the top of the groove The entire locking bar arrangement is therefore contained within the groove This is advantageous, as it saves space, will not interfere with the closing of the window or door and the entire mechanism is hidden from view and protected from damage when the window or door is open.

Most modern UPVC windows and doors have a standard "Eurogroove" section, and therefore the mechanism can be made to fit this Preferably, the bolt section moves inside the groove in the frame and the force transmitting section moves in a plane above the plane in which the bolt section moves.

Preferably, at the point of coupling between the two sections of the locking bar, there is an elongate slot through both sections so that a screw may be fixed through the coupling and into the frame The slot is elongate so that the locking bar may still move to lock and unlock the bolt The screw prevents the coupling from disengaging if a force on the end of the bar causes the bar to buckle.

Preferably, one of the sections includes a central elongated slot extending along substantially its entire length, and the end section of the other section includes an elongated slot having a length corresponding to the throw of the bolt The screw is positioned such that, as the bolt moves from its fully extended position to its fully retracted position, the slot moves such that the screw is positioned at one end of the slot when the bolt is fully extended and the screw is positioned at the other end of the slot when the bolt is fully retracted.

Preferably, the coupling is achieved by means of a portion of one of the two sections having internal teeth which mates with a portion of the other section having external teeth On one section the teeth extend along a substantial portion of the length of the section, so that the position of the coupling may be varied to adjust the length of the locking bar On the other section, the toothed portion extends into the plane of movement of the other section to form the coupling.

Preferably, the force transmitting section includes an engaging portion having internal teeth which extends downwards into the groove to engage with external teeth on each side of the bolt section The external teeth on the bolt section extend along a substantial portion of the length of the section The bolt section further includes a central slot which also extends along a substantial portion of the length of the section The engaging portion of the force transmitting section includes an elongated slot having a length corresponding substantially to the throw of the bolt Preferably, the engaging portion also includes two projections at either end of the elongate slot which engage in the central groove of the bolt section.

These prevent the two parts of the bolt section either side of the central slot from deforming inwards and disengaging from the teeth on the force transmitting section.

The drive mechanism and force transmitting section may be covered with a cover plate.

A preferred embodiment of the present invention will now be described with reference to the accompanying drawings in which:

Figure 1 shows a side elevation of a first embodiment of the present invention; Figure 2 shows the coupling of the force transmitting section and the bolt section and the guide member of the first embodiment of the present invention; Figure 3 shows a bolt section of the first embodiment of the present invention; Figure 4 shows an engaging portion of a force transmitting section of the first embodiment of the present invention; Figure 5 shows a side elevation of a first embodiment of the present invention with the cover plate in position; Figure 6 shows a side elevation of a first embodiment of the present invention with the bolt protecting cover in position; Figure 7 shows a section of the engagement between the bolt section and the force transmitting section; and Figure 8 shows a side elevation of a second embodiment of the present invention.

A shoot bolt mechanism comprises a drive mechanism 1 which is coupled to two locking bars 2 a, 2 b such that rotational movement of a handle which fits into the square hole 20 causes translational movement of the locking bars 2 a, 2 b in opposite directions Each of the locking bars 2 a, 2 b comprise two sections, a force transmitting section 3 which is coupled to the drive mechanism 1 and a bolt section 4 The bolt section 4 moves in a groove in the end face of a window or door, and the force transmitting section 3 moves in a plane above this such that a part of the two sections overlaps Each bolt section 4 has external teeth 5 on both sides along a substantial portion of its length An engaging portion 6 of the force transmitting section 3 extends into the plane of movement of the bolt section 4 and has internal teeth which engage with the external teeth 5 on the bolt section The length of the locking bar 2 may be adjusted by moving the position at which the engaging portion 6 couples with the external teeth 5 along the bolt section 4 The end of the bolt section 4 passes through a guide member 7 which is fixed to the corner of the window or door frame The guide member 7 includes a hole 8 for receiving a shear pin (not shown) The shear pin passes through the hole 8 and engages in a hole 14 in the bolt section, as shown in Figure 3 which shows a single bolt section 4 The hole 14 is positioned such that the shear pin holds the bolt section 4 in its fully retracted position This aids in assembling the shoot bolt mechanism First the bolt sections 4 are fitted into the groove in the window or door frame and the guide members 7 are fixed onto the corners of the frame, with the shear pins in position, and then the drive mechanism 1 and force transmitting sections 3 are positioned and the force transmitting sections 3 are coupled to the bolt sections 4, with the mechanism in the fully retracted position On the first operation of the shoot bolt, the shear pin is shorn off to allow free movement of the bolt section 4.

Figure 2 shows in detail the coupling between the engaging portion 6 of the force transmitting section 3 and the bolt section 4 The bolt section 4 has external teeth along both sides, and a central elongate slot 9 As shown in Figure 4 which shows the engaging portion alone, the engaging portion 6 has internal teeth 15 on the inside walls of its side portions 10 a, 10 b which engage with the external teeth 5 on either side of the bolt section 4 to couple the bolt section 4 to the force transmitting section 3 The engaging portion 6 includes an elongate slot 11 which aligns with the slot 9 in the bolt section The elongate slot 11 has a length which generally corresponds to the throw t of the bolt A screw may then be fixed through both slots 9, 11 such that the locking bar 2 is still allowed to move by the necessary amount The engaging portion 6 further includes two projections 12 a, 12 b at either end of the slot 11 which engage in the central slot 9 of the bolt section 4 to prevent the sides a, 10 b of the bolt section 4 from deforming inwards and causing the teeth 5 on the bolt section 4 to disengage from the teeth 15 on the engaging portion 6 Figure 2 also shows the guide member 7 The guide member 7 includes an opening 19, through which the end of the bolt section 4 passes The bolt section 4 includes shoulders 13 which prevent it from passing through the opening 19 beyond a point of maximum extension of the locking bar which corresponds to the throw t of the bolt.

Figures 5 and 6 show how the cover plate 16 and the bolt protecting cover 17 are assembled After the locking bars 2 and the guide members 7 are in position, the cover plate 16 is fixed over the drive mechanism 1 and the force transmitting sections, including the engaging portions 6.

A bolt protecting cover 17 is then fixed over the bolt section 4 The bolt protecting cover 17 is formed from a flexible plastics material and can be slotted in position at one end under the edge of the cover plate 16 and at the other end under the edge of the guide member 7 The cover plate 16 has a hole 18 for receiving a screw 21 which passes through the bolt protecting cover 17, the elongate slot 11 in the engaging portion 6 and the central slot 9 in the bolt section 4 to screw into the frame of the window or door This is shown in section in Figure 7 The hole 18 is positioned to align with the near end of the slot 11 if the mechanism is to be fitted in the fully extended position, as illustrated in Figures 6 and 7, or may be positioned to align with the far end of the slot 11 if the mechanism is to be fitted in the fully retracted position.

Figure 8 shows a second embodiment of the present invention wherein the force transmitting section 3 runs inside the groove in the frame and has internal teeth 15 along a substantial portion of its length The bolt section (not shown) runs in a plane above the plane in which the force transmitting section 3 moves, and has a downwardly projecting engaging portion having external teeth for engaging with the internal teeth 15 on the force transmitting section 3 The force transmitting section 3 may be provided with a central slot along a substantial portion of its length, and the engaging portion of the bolt section may have a corresponding slot having a length equivalent to the throw of the bolt.

Claims (8)

1 A locking bar arrangement for mounting on an end face of a window or door, the end face having a groove therein, comprises at least one locking bar comprising a force transmitting section for transmitting force from a mechanism, and a bolt section coupled to the force transmitting section, wherein one section moves in a first plane inside the groove in the frame and the other section moves in a second plane located above the first plane, such that the ends of the two sections of the locking bar overlap, wherein means are provided to adjustably couple the two sections of the locking bar to vary the length of the locking bar.

2 A locking bar arrangement according to claim 1, wherein the other section moves in a plane which is also inside the groove, or substantially parallel with the top of the groove.

3 A locking bar arrangement according to claim 1 or 2, wherein the bolt section moves inside the groove in the frame and the force transmitting section moves in a plane above the plane in which the bolt section moves.

4 A locking bar arrangement according to any one of the preceding claims wherein, at the point of coupling between the two sections of the locking bar, there is an elongate slot through both sections so that a screw may be fixed through the coupling and into the frame.

A locking bar arrangement according to claim 4, wherein one of the sections includes a central elongated slot extending along substantially its entire length, and the end section of the other section includes an elongated slot having a length corresponding to the throw of the bolt.

6 A locking bar arrangement according to any one of the preceding claims, wherein the coupling is achieved by means of a portion of one of the two sections having internal teeth which mates with a portion of the other section having external teeth.

7 A locking bar arrangement according to claim 6, wherein on one section the teeth extend along a substantial portion of the length of the section.

8 A locking bar arrangement substantially as described herein with reference to the accompanying drawings.