WO2007015077A1

WO2007015077A1 - Panic latch assembly

Info

Publication number: WO2007015077A1
Application number: PCT/GB2006/002848
Authority: WO
Inventors: Lee Barry Trethaway
Original assignee: Fred Duncombe Ltd.
Priority date: 2005-08-01
Filing date: 2006-07-31
Publication date: 2007-02-08
Also published as: GB2428734B; GB0515808D0; GB2428734A

Abstract

A release device for a panic latch of a hinged door includes an operating member (21) with opposite curved horns (22). Pivoting of the release lever causes the horns to actuate opposite slide bolts. The arrangement allows the pivot axis to be on one side of the chassis allowing the release mechancism to have a low height with respect to a door frame.

Description

Panic Latch Assembly

This invention relates to panic latch assemblies of the kind used on panic and emergency exit doors in public buildings.

A typical panic latch assembly is operable by pushing from the inside of a building to release upper and lower bolts, thereby allowing a door (or window) to swing outwards. Often the release mechanism will include a push pad, or a bar extending transversely so that the bolts will be released by pressure at any point across the width of the opening. The release mechanism may also include a side latch for engaging the adjacent vertical face of a frame or another door, and must usually have provision for an outside access device whereby the latch assembly can be released from outside the building.

Certain problems arise with existing panic latch assemblies. It is difficult to ensure sufficient stroke of the bolts whilst maintaining a reasonable operating force, and a relatively small protrusion of the release mechanism. Generally speaking the input/output stroke ratio is a compromise so that whilst greater gearing-up can reduce input stroke, the consequence is that operating forces increase correspondingly.

The height of the assembly above the face of the door must be low if it is not to foul on the door frame as the door swings open. This is especially true if an integral side latch is provided, because in this case the assembly must be mounted at the door edge. A suitable lever mechanism can be devised which may approach the desired output stroke, but in this case the body of the latch assembly tends to be wide.

What is desirable is a panic latch assembly which gives the required output stroke with low input force, small input travel, and which is also suitable for mounting on a narrow stile, having a width in the range 40-50 mm. According to one aspect of the invention there is provided a release device for opposite bolts of a hinged closure and comprising: a chassis having a base plane, and defining an output axis over said base plane, opposite connection members movable together on said output axis from a relatively apart condition, the connection members being for attachment with opposite bolts of a hinged closure, and a release mechanism for urging said connection members along said output axis, wherein said release mechanism comprises: a release lever pivotable in said frame about a pivot axis parallel to said output axis, said pivot axis and output axis being non-orthogonal with respect to said base plane, and said release lever having depending horns associated one each with said connection members, said horns diverging and crossing said output axis, and said connection members being engageable with respective said faces of said horns whereby pivoting of said release lever draws said connection members together.

This arrangement permits the pivot axis to be on one side of the chassis, thus allowing that side to have a low height with respect to the face of the leaf on which the chassis is mounted. The low height side is suitable for the edge of the leaf so as to impede as little as possible the opening thereof.

The other side of the chassis, being away from the edge of the leaf can be of greater height whilst not impeding clearance of the frame. Thus the release lever can be permitted to swing above the pivot axis (with respect to the face of the leaf), and this in turn allows a greater mechanical advantage than is possible with the pivot and output axes mutually orthogonal to the face of the leaf. In the preferred embodiment the chassis includes an upright side wall defining one edge thereof, and the pivot axis is adjacent this edge; substantially the whole width of the chassis is thus available for the horns of the release lever, allowing maximum mechanical advantage.

The horns are preferably arcuate so that pivoting thereof is within a relatively small envelope.

Preferably the connection members are resiliently biased away from each other, and in the preferred embodiment individual coil compression springs are provided for each connection member and reacting against a respective end of the chassis.

In the preferred embodiment the release lever further includes an input arm extending away from the pivot axis, and a pivotable input member bearing on said arm, movement of the input member pivoting the release lever so as to draw said connection members together.

In the preferred embodiment the pivoting axis of said input member is orthogonal to said pivot axis and on the opposite side with respect to the output axis. The input member preferably bears on the underside of said arm, and consequently lies between said arm, and said base plane.

In the preferred embodiment the release lever is substantially symmetrical and has two input arms, one arm being on each side of the pivoting axis and the input member. The advantage of this arrangement is that pivoting movement of the input member in either direction from a mean position will cause the release arm to move unidirectionally. Thus the device can be made easily suitable for both left and right hinged doors and windows. Preferably the chassis includes opposite upright sides, the pivot axis of the input member being defined by apertures in said sides. In a preferred embodiment the input member includes a shaft pivotable in said apertures and extending axially through the side opposite said pivot axis for connection to an operating means, such as a handle.

Preferably the device includes a close fitting one-piece cover, the shaft protruding from said cover. The operating means may comprise a paddle extending radially from said shaft at about 45° to said base plane in the mean position of the input member. This arrangement permits operation of the device by pushing the paddle towards the door leaf, and allows repositioning of the paddle by 90° in the event that the device is turned upside down for fixing to an opposite door stile.

In the preferred embodiment, the input member is slidable along the pivot axis thereof against a resilient bias to disengage said operating handle and permit free pivoting of the operating handle to an alternative position. Drive between the input member and the operating handle may for example be by way of a peg of one component engaging in a recess of the other component, and being axially separable. By providing, for example, one peg and two recesses, the operating handle can be arranged to adopt one of two orientations. A further shallow peg and recess combination may be provided to hold the operating handle at a mid-position, from which it can be dislodged into one or other operating positions. In this way a handle may be allowed to fall into the correct 45° operating orientation, depending on which way up the device is fixed to an opening leaf.

Other features of the invention will be apparent from the following description of a preferred embodiment in which:-

Figs. 1-3 show schematic illustrative views of an assembly according to the invention, at different stages of release. Fig. 4 shows illustratively various components of the kind of latch shown in Fig. 1.

Fig. 5 shows how the latch of the invention clears a door frame whilst being mounted on a door stile.

Figs. 6 and 7 show illustratively some further components of the kind of latch illustrated in Fig. 1.

A panic latch assembly 10 comprises a chassis 11 of folded steel plate which is adapted to be secured to the hinged leaf of a door or window, and has upper and lower shoots 12,13 slidable towards and apart in use, on a substantially vertical axis. The shoots 12,13 are adapted for connection to latches mounted at the top and bottom of the leaf, for engagement respectively in the horizontal members framing the leaf.

Upstanding at either side of the chassis are planar flanges 14,15 which have facing apertures 16,17 to define a transverse pivot axis for an operating handle 18.

The flange 14, which is in use adjacent the edge of the leaf, has inturned ears 19 having facing apertures to define an upright pivot axis 20 for an operating member 21. This operating member has symmetrical curved horns 22 which engage upstanding pairs of pins 23 of the shoots 12,13, so that pivoting of the member 21 moves the shoots longitudinally of the chassis.

As illustrated an inner side of each horn acts on one respective pin to draw the shoot inwardly, whereas an outer side of each horn acts on another respective pin to urge the shoots outwardly. As an alternative, the shoots 12,13 may be resiliently biased in one direction, for example outwardly, so that only the inner faces of the horns are operational (and accordingly one pin 23 of each pair can be omitted).

The operating member also includes symmetrical arms 24 which project towards the inner flange 15 for engagement by opposite arms of a swing hammer 25 which is pivotable with the handle 18. The swing hammer 25 lies under the arms 24, so that pivoting motion of the handle 18 causes one or other of the arms to lift, thereby pivoting the operating member 21, and causing the shoots to be drawn in. It will be appreciated that pivoting of the operating handle away from a mid-position in either direction has the same effect, namely drawing-in of the shoots.

Also illustrated is an optional side latch 26, also pivoted about the upright pivot axis of the operating member 21. This side latch 26 is adapted to be drawn in by a lower arm of the operating member (which links the inner ends of the horns 22) on pivoting thereof. The side latch 26 may also pivot inwardly independently of the operating member, for which purpose a hairpin return spring may be provided.

In use, a mounting plate 30 is attached to the leaf of a door or window adjacent one side edge, for example using a template. The assembly 10 is attached to the mounting plate 30 and the cover 31 is secured. The upper and lower shoots are connected to suitable extension pieces for upper and lower bolts, and if required a horizontal operating bar and slave pivot arm are provided for the operating handle 18.

As illustrated in Fig. 1, the operating handle 18 is in the unactivated condition in which the shoots 12,13 and side latch 26 are outward, and the arms 24 are in a plane generally parallel to the mounting face of the leaf. Movement of the handle 18 towards the leaf causes pivoting of the operating member 21 so that both the shoots 12,13 and side latch 26 are drawn in progressively (Fig. 2) to a fully withdrawn condition (Fig. 3).

In this withdrawn condition it will be noted that additional height clearance is not required at the side adjacent the edge of the leaf, but that additional clearance is required at the operating handle side. This arrangement has particular operational advantages in providing opening clearance at the leaf edge, and consequently allows a panic latch assembly according to the invention to be mounted on a narrow stile.

Fig. 4 illustrates (on different scales) certain of the component parts of the assembly, including a mounting plate 40 for attachment to a leaf via countersunk screws, and a cover 41. The pivot axis of side latch 26 is not shown.

Fig. 5 shows in transverse section a door 50 having narrow stiles 51 between which is provided a panel 52 which is non-structural (such as glass). A panic latch assembly 10 is mounted to the non-hinged edge, and has an operating handle 18. The asymmetric nature of the cover ensures that the relieved area 53 clears the adjacent frame 54 as the door is pushed open in the direction of arrow 55. Thus by virtue of the operating member 21 having a pivot axis on the door edge side, an assembly with sufficient stroke to withdraw the upper and lower bolts can be mounted on a narrow stile in an effective manner.

Figs. 6 and 7 show respectively the swing hammer 25 and a handing piece 27.

With reference to Figs. 1-3, the operating handle 18 is connected to a shaft 28 which is pivotable in the chassis. The handing piece 27 is also connected to the shaft 28 and pivotable therewith. Freely journalled on the shaft is the swing hammer 25, which has an axially directed projection 31 adapted to engage in one or other of two corresponding recesses 32 of the handing piece 27. The pivoting axis 33 of shaft 28 is illustrated in Figs. 6 and 7.

The swing hammer 25 is urged towards the handing piece 27 by a coil compression spring (not shown), which itself reacts against the flange 14, or any other relatively fixed component of the assembly. Orientation of the swing hammer 25 is substantially fixed in the rest position by virtue of the arms 29 bearing on the arms 24 of the operating member.

Thus pivoting of the handle is permitted until the projection 31 engages one of the recesses 32, by virtue of the load of the compression spring. At this point the operating handle 18 is coupled to the swing hammer 25, and pivoting of the handle causes inward movement of the shoots 12,13. The swing hammer 25 may be disengaged by axial movement against the force of the compression spring, thus permitting the handle to be pivoted to the alternative position in which the other recess 32 is engaged by the projection 31. In this way the device is adapted for left and right hand door edge mounting.

The handling piece 25 may include a shallow recess in the finger 34 which lies between the recesses 32 so as to permit the operating handle to be retained in a mid- position, typically in an orthogonal plane with respect to the base plane of the chassis. On fixing of the device the handle can be dislodged into the correct operating condition, which is a consequence of left or right hand edge mounting, and the projection 31 is engaged in the corresponding recess 32 to give a semi- permanent fixing.

In a preferred embodiment, a 45° movement of the operating handle provides about 12 mm of withdrawal for each shoot, in a chassis with a minimum cover height (at the door edge) of about 52 mm, a maximum cover height of about 60 mm, and a cover width of about 38 mm.

Claims

1. A release device for opposite bolts of a hinged closure and comprising: a chassis having a base plane, and defining an output axis over said base plane, opposite connection members movable together on said output axis from a relatively apart condition, the connection members being for attachment with opposite bolts of a hinged closure, and a release mechanism for urging said connection members along said output axis, wherein said release mechanism comprising: a release lever pivotable in said frame about a pivot axis parallel to said output axis, said pivot axis and output axis being non-orthogonal with respect to said base plane, and said release lever having depending horns associated one each with said connection members, said horns diverging and crossing said output axis, and said connection members being engageable with respective said faces of said horns whereby pivoting of said release lever draws said connection members together.

2. A device according to claim 1 wherein said chassis includes an upright side wall defining one edge thereof, and said pivot axis is adjacent said edge.

3. A device according to claim 1 or claim 2 wherein said horns are arcuate.

4. A device according to any preceding claim wherein the connection members are resiliently biased away from each other.

5. A device according to claim 4 wherein individual coil compression springs are provided for each connection member and reacting in use against a respective end of said chassis.

6. A device according to any preceding claim wherein said release lever further includes an input arm extending away from said pivot axis, and a pivotable input member bearing on said arm, movement of the input member pivoting said release lever so as to draw said connection members together, in use.

7. A device according to claim 6 wherein the pivoting axis of said input member is orthogonal to the pivot axis of said release lever, and on the opposite side with respect to the output axis.

8. A device according to claim 6 or claim 7 wherein said input member bears on the underside of said arm.

9. A device according to any of claims 6-8 wherein said release lever is substantially symmetrical and has two input arms, one arm being on each side of the pivoting axis of said input member.

10. A device according to any of claims 6-9 wherein said chassis includes opposite upright sides, the pivot axis of the input member being defined by apertures in said sides.

11. A device according to claim 10 wherein said input member includes a shaft pivotable in said apertures and extending axially through the side not adjacent the pivot axis of said release lever, to an operating handle.

12. A device according to claim 11 and further including a close fitting one-piece cover, the shaft protruding from said cover.

13. A device according to claim 11 or claim 12 wherein said handle comprises a paddle extending radially from said shaft at about 45° to said base plane in the mid- position of the input member.

14. A device according to any of claims 11-13 wherein said input member is slidable along the pivot axis thereof against a resilient bias to disengage said operating handle and permit free pivoting of the operating handle to an alternative position.

15. A device according to claim 14 wherein drive between the input member and the operating handle is by way of axially separable peg and recess.

16. A device according to claim 15 and provided with one peg and two recesses to permit said operating handle to adopt one of two orientations.