GB2313618A

GB2313618A - Shoot bolt drive mechanism

Info

Publication number: GB2313618A
Application number: GB9707502A
Authority: GB
Inventors: Jason David Paddock
Original assignee: CHADWICK ANTHONY; Trojan Hardware and Design Ltd
Current assignee: CHADWICK ANTHONY; Trojan Hardware and Design Ltd
Priority date: 1996-04-17
Filing date: 1997-04-16
Publication date: 1997-12-03
Anticipated expiration: 2017-04-16
Also published as: GB9707502D0; GB2312236A; GB2312236B; GB9704893D0; GB2313618B; GB2313617A; GB9607908D0; GB9705294D0; GB2313617B

Abstract

In a drive for a bi-directional shoot bolt mechanism, for securing doors and windows, a quadrant gear 14 is arranged to drive two racks 18,20, one rack being secured to each of two bolt arms 22,24. One rack 18 engages the quadrant gear 14 directly. The other rack 20 is driven through a pinion wheel 16 which is itself in engagement with a second set of teeth on the quadrant gear 14, offset by half of one pitch, thereby to result in the two bolt arms 22,24 being driven in opposite directions upon rotations of the quadrant gear 14. A larger quadrant gear 52 and two reversing pinions 54,56 (Figure 8) may instead be employed to achieve a longer throw of the bolt arms 22,24.

Description

2313618 SHOOT BOLT MECHANISM This invention is concerned with improvements

in or relating to bidirectional shoot bolt mechanisms such as are used for securing opening 5 windows and doors in closed positions.

Such mechanisms comprise a housing for a drive mechanism which is adapted to be accommodated in a recess in an edge member of a window or door. Two bolt arms extend in opposite directions from a 10. front face of the drive mechanism, to be moved longitudinally by the mechanism. The bolt arms are ordinarily adapted to be accommodated in shallow channels formed in the edge member, end portions of the arms being projectable beyond guide members, secured to corners of the window or door, for engagement with keeps on an adjacent window or door frame. In an open condition of the mechanism, the bolt ends are drawn back from the keeps to the guide members to permit the window or door to be opened.

For securement in edge members of standardised extruded section, it is necessary that the dimensions of the drive mechanism housing come within certain predetermined limits. In particular, the depth of the mechanism from front to rear is so limited. For operation by means of a handle, the mechanism ordinarily comprises a primary drive gear (commonly a quadrant gear) which is slotted axially to receive a drive spindle on which the handle is fixed. It is necessary that the spindle axis be well removed from the front face of the edge member and, therefore, that the primary drive gear be positioned as rearwardly as possible within the housing. Intermediate drive mechanism, acting between the primary drive gear and transmission links of the bolt arms, needs to be 2 accommodated between the primary drive gear and the front face of the mechanism.

This arrangement means that there tends to be a front to rear thrust on the primary drive gear in operation. The thrust has to be borne by the housing and, as a consequence of this, some of the available depth for the mechanism is usually occupied by a rearmost portion of the housing supporting the primary gear. This in turn has limiting implications for the design of the primary drive gear and intermediate mechanism.

It is an object of the present invention to provide improvements relating to the design of shoot bolt drive mechanisms which enables more effective use to be made of the limited space available.

is The invention provides, in one of its aspects, a shoot bolt mechanism comprising a housing for a primary drive member arranged upon rotation to drive two bolt arms in opposite directions, the member comprising at least one end portion forming a hub which is arranged to be engaged by a drive spindle from outside the housing, the member being interengaged with the housing at a position radially between the hub and the bolt arms whereby to support the drive member radially during rotation in driving the bolt arms.

With less reliance on the rear wall of the housing for support of the drive member, the wall can be made thinner or even partially removed and the drive member enlarged.

The hub is preferably supported in a bearing formed by the housing.

3 In a preferred construction, the interengagement between the drive member and the housing is effected by means of a part-annular flange of the housing which is accommodated in a groove in the drive member, preferably adjacent to the surface of the hub. Alternatively, a flange on 5 the drive member could be arranged to engage in a groove of the housing.

Each bolt arm may be driven from the primary gear by means of a toothed rack. In a preferred arrangement, one of the racks engages the primary drive gear directly and the other is engaged with a reversing pinion which is engaged with the primary drive gear, whereby the two bolt arms become driven in opposite directions upon rotation of the primary drive gear.

Such an arrangement can provide the advantage of being very compact, and can also enable the reversing gear to be well constrained.

There now follows a detailed description, to be read with reference to the accompanying drawings, of a shoot bolt mechanism which illustrates the present invention by way of example.

In the accompanying drawings:

Figure 1 is a side view of an operating mechanism (with a housing half removed) in an open condition of the shoot bolt mechanism; Figure 2 is a front face view of the operating mechanism, seen in the direction of arrow A in Figure 1; Figure 3 is an enlarged view in section on line III-III of Figure 1; 4 Figure 4 is a view similar to Figure 1 but with the mechanism in a closed condition; Figure 5 is a view similar to Figure 2 but with the mechanism in its closed condition; Figure 6 is an enlarged view in section on line VI-VI of Figure 4; Figure 7 is a face view of an end portion of the shoot bolt mechanism including a bolt end inserted through an end guide; Figure 8 is a side view of the assembly shown in Figure 7; Figure 9 is a view in section on line IXAX of Figure 8; and is Figure 10 is a face view on an enlarged scale of means securing the bolt end to a transmission link extending from the operating mechanism.

An operating mechanism of a bi-directional shoot bolt, for securing a window or door, is shown in Figures 1 to 6. Two halves 10, 12 of a housing provide support between them for a primary-drive quadrant gear 14, a reversing pinion 16 and first and second racks 18 and 20 of two transmission links comprising bars 22,24 of oppositely directed bolts.

The quadrant gear 14 is formed with an axially aligned slot 26 of square cross-section to receive a drive spindle which is secured to an operating handle (spindle and handle not shown, but can be of conventional form). As seen in Figures 1 and 3, the slot 26 extends through a cylindrical hub-forming portion 28 of the quadrant gear which is of equal axial length to the width of the housing. A tooth-providing crest 30 of the gear extends about part only of the circumference of the hub-forming portion 28, being of shorter length than the hub-forming portion and being positioned centrally (in the axial direction). At each end of the gear, a groove 32,34 is cut into the root of the crest, adjacent to the cylindrical surface of the hub-forming portion 28, the groove extending about the hub-forming portions for the full extent of the crest 30.

The grooves 32,34 provide part-circular, open-ended, recesses to receive flanges 36,38, of corresponding dimensions, projecting inwardly from the housing halves 10,12; the grooves 32,34 and flanges 36,38 are concentric with the axis of the quadrant gear 14, and the flanges 36,38 bound circular openings 40,42 in which opposite end portions of the hub- forming portion 28 of the gear are received.

The flanges 36,38 of the housing halves provide radial support for the quadrant gear in the direction away from the racks 18,20 and reversing pinion 16. This support reduces the demands on the housing halves at the openings 40,42 which form further bearings for the hubforming portion 28 of the quadrant gear. As a consequence, it is not necessary for the housing to surround the quadrant gear completely and, as best seen in Figures 1 and 4, the rearmost surface 44 of the hubforming portion of the gear is exposed through an opening in the housing and is generally flush with a rear face 46 of the housing. Rotation of the quadrant gear is so guided by the combination of the flanges 36,38 and the part-cylindrical bearing surfaces formed by the housing halves around the openings 40,42.

6 The teeth of the quadrant gear are held in engagement with the teeth of the first rack 18. Upon.rotation of the quadrant gear clockwise from a starting position (shown in Figure 1) to a finishing position (shown in Figure 4) the rack and its associated transmission bar 22 are driven from left to right, as seen in the drawings, the two quadrant positions corresponding with fully open (Figure 2) and fully closed (Figure 5) conditions of the shoot bolt mechanism.

The quadrant gear teeth are also held in engagement with the reversing pinion 16, and the pinion is held in engagement with the teeth of the second rack 20. In rotating the quadrant gear from its starting position to its finishing position the second rack and its associated transmission bar 24 are, therefore, driven in the opposite direction from the first rack and transmission bar (i.e. from right to left).

The pinion 16 and first rack 18 are positioned side by side (i.e. axially spaced) on the quadrant gear and the two racks 18,20 are likewise spaced axially of the gear, the teeth of the second rack 20 being at a greater radial distance from the axis of the gear for accommodation of the reversing pinion therebetween. The transmission bars 22,24 are of flat strip form and are retained in place by means of a cover plate 48 applied to the front face of the housing.

As shown in Figures 7 to 10, each of the transmission bars 22,24 (bar 22 only being shown in the drawings, bar 24 being utilised in exactly the same manner) is secured towards its outer end to an end piece comprising a strip of suitable length forming a bolt end 50. As shown in Figure 9, the bolt end 50 is narrower than the transmission bar and extends beneath the bar, where they overlap, supported in an inner portion 52 of an extruded plastics channel 54. The broader transmission 7 bar 22, overlying the bolt end 50, is supported in an outer portion 56 of the channel, inturned outer margins 58,60 of the channel preventing the bar from lifting out.

The channel 54 extends continuously from the cover plate 48 of the operating mechanism to an L-shaped end guide member 62. Both the long and the short limbs of the guide member are arranged to be secured by fixing screws 64 to a frame corner. The short limb provides a slot 66 (extending perpendicularly to the long limb) through which the bolt end 50 is received to slide, the bolt end sliding over an inner portion of the limb which forms a fixing plate 68 by means of which the limb has previously been screwed to the frame. By means of this arrangement, it is not necessary for the bolt end to be slotted to give clearance for fixing screws, and furthermore the bolt end can be slid out through the guide member (when released from the transmission bar) without the need to remove guide member fixing screws.

The bolt end 50 is arranged to be secured in adjusted positions to the transmission bar 22 by clamping means shown in Figures 7,8 and 10.

An end portion of the transmission bar 22 is longitudinally slotted, serrated edges 70 being provided along each side of the slot 72. A clamp positioning member 74 comprises a plate-like portion 76, forming a head of the member to overlie the transmission bar, and a generally rectangular engagement portion 78 beneath the head to fit (in one orientation of the clamping member) into the slot 72. The engagement portion has serrated side edges to engage with the serrations of the slot edges 70, so that with the positioning member engaged in the slot it cannot move longitudinally of the slot. A headed screw 80 passed through a central hole in the positioning member into a tapped hole in the bolt end clamps the assembly together, preventing movement of the bolt end relative to the transmission 8 bar. To increase the range of possible adjustment, there are three longitudinally-spaced tapped holes 82 provided in the bolt end. As shown in Figure 10, upon slackening the screw 80 the engagement portion 78 of the positioning member 74 can be lifted out of the slot 72 and the member rotated through 90' to lie across the outer face of the transmission bar during adjustment of the position of the bolt end 50.

Claims

9 CLAIMS

1. A shoot bolt mechanism comprising a housing for a primary drive member arranged upon rotation to drive two bolt arms in opposite directions, the member comprising at least one end portion forming a hub which is arranged to be engaged by a drive spindle from outside the housing, the member being interengaged with the housing at a position radially between the hub and the bolt arms whereby to support the drive member radially during rotation in driving the bolt arms.

2. A mechanism according to claim 1 in which the hub is supported in a bearing formed by the housing.

3. A mechanism according to either of claims 1 and 2 in which the interengagement between the drive member and the housing is effected by means of a part-annular flange of the housing being accommodated in a groove in the drive member.

4. A mechanism according to either of claims 1 and 2 in which the interengagement between the drive member and the housing is effected by means of a part-annular flange on the drive member being accommodated in a groove in the housing.

5. A mechanism according to either of claims 3 and 4 in which the flangelgroove interengagement is at a position adjacent to the hub.

6. A mechanism according to any one of the preceding claims in which each bolt is arranged to be driven from the primary gear by means of a toothed rack which is accommodated between the primary gear and the bolt arm.

7. A mechanism according to claim 6 in which one of the racks engages the primary drive gear directly and the other is engaged with a reversing pinion which is engaged with the primary drive gear, whereby the two bolt arms become driven in opposite directions upon rotation of the primary drive gear.

8. A shoot bolt mechanism substantially as hereinbefore described with reference to the accompanying drawings.