GB2330173A

GB2330173A - Catch mechanism

Info

Publication number: GB2330173A
Application number: GB9815994A
Authority: GB
Inventors: Terence James Dolman
Original assignee: Trojan Hardware and Design Ltd
Current assignee: Trojan Hardware and Design Ltd
Priority date: 1997-07-24
Filing date: 1998-07-23
Publication date: 1999-04-14
Also published as: GB9815994D0; GB2327706A; GB9815993D0; GB9715521D0; GB2327706B

Abstract

A catch mechanism (36) for a slider (34), eg for a scissors window hinge, which is mounted for movement along a guide rail, is adjustable between a first condition in which the slider (34) in movement along the rail is arrested automatically by engagement with a locking formation (38) at a locking position on the rail and a second condition in which the slider is arranged not to become so arrested. The slider (34) comprising a locking body (76) and a biasing spring (78) arranged in the first condition, but not in the second condition, to raise a locking formation of the body to become interengaged with the locking formation (38) of the rail when the slider becomes moved to the locking position.

Description

2330173 1 IMPROVED CATCH MECHANISM This invention relates to an improved

catch mechanism. It is expected to find application principally to sliding mechanisms for side hung and top hung window vents, but could find application to other similarly movable panels and mechanisms.

There is described in GB-A-2 304 148 a scissors-type hinge mechanism which comprises a frame rail adapted for securement to a window frame, a sash rail adapted for securement to the window sash, and a pair of pivotally joined supporting links which interconnect the two rails. The opposite ends of one of the links are pivotally secured in fixed positions on the frame and sash rails respectively, and the opposite ends of the other link are pivotally secured to movable sliders on the two rails.

Such a hinge mechanism can be arranged to enable the vent to be opened to substantially 90', and may be arranged to provide for substantially unobstructed egress through the open window in an emergency. However, a practical difficulty can arise from an inner edge of the vent (adjacent to the hinge) being positioned very close to the window frame. Whilst this is desirable in order to minimise egress obstruction, it can mean that it is very difficult to reach outside surfaces of the window for cleaning.

To overcome this difficulty, it is known with other hinge mechanisms to arrange for the window to be movable bodily along the window frame, into a cleaning position, through releasing the link pivot which is normally fixed (via the rail) to the frame; after releasing the fixed pivot, both it and the adjacent movable slider can be slid (with the window) along the frame rail towards the middle of the window frame. In 2 this manner a suitably large gap can be created between the frame and the inner edge of the vent to enable the outside of the window to be accessed.

The use of a restrictor arm is commonly associated with such hinges, the arm extending to a slider in the frame rail from a suitable pivotal fixed point at its other end on the sash rail or on one of the supporting links. A catch mechanism, associated with the slider and engaging with the frame rail, enables the window to be secured open at one or more intermediate positions, for example to provide restricted opening for child safety purposes. It is known to take advantage of such a restrictor to provide leverage for movement of the window into a cleaning position, the arm (with its catch engaged) serving to draw the links of the hinge mechanism along the frame rail towards the catch as the window is pushed open.

is It is an object of the present invention to provide an improved catch mechanism for use with a restrictor arm or other such element.

In accordance with a first aspect the invention provides a catch mechanism for a slider which is mounted for movement along a guide rail, the mechanism being adjustable between a first condition in which the slider in movement along the rail is arranged to become arrested automatically by engagement with a locking formation at a locking position on the rail and a second condition in which the slider is arranged not to become so arrested, the slider comprising a locking body and biasing means arranged in the first condition but not in the second condition to cause a locking formation of the body to become interengaged with the locking formation of the rail when the slider becomes moved to the locking position.

3 In a preferred construction the locking body is pivotable forwardly and rearwardly in the direction of the length of the guide rail between a first orientation in which its locking formation is raised (and thereby out of engagement with the locking formation on the rail when in the locking position) and a second orientation in which its locking formation is lowered and in engagement with the locking formation in the locking position. The biasing means may comprise a leaf spring which at a first end is secured heightwise relative to the rail and which at its other end is arranged to bear down on the locking body to urge the body to pivot into its second orientation. In the first condition of the catch mechanism the locking body is free to pivot between its first and second orientations, so that the slider can be moved along the rail with the body in its first orientation but will become arrested upon returning to the locking position owing to the spring causing the body to rock into its second orientation.

In its second condition, the locking body may be held in a third orientation and prevented from moving to its second orientation by engagement of an end portion of the locking body with the first end of the spring. The third orientation may be substantially the same as the first orientation.

The guide rail may comprise a channel having an upwardly facing bottom wall and side walls supporting opposed inwardly directed edge flanges which are spaced from but overlie the bottom wall. The first end of the spring may lie at least partially below the edge flanges of the guide rail. In its second condition, the end portion of the locking body may be held between the bottom wall of the guide rail and the first end of the spring.

4 The locking body may have at least two undersurfaces which lie in two planes which are inclined to one another. In the first orientation, one of -the undersurfaces may lie in contact with the bottom wall of the guide rail. In the second orientation, the one undersurface may lie at an angle to (out of contact with) the bottom wall. In this case the locking formation may engage the bottom wall of the guide rail. Movement from the first orientation to the second orientation may be by pivoting about the portion of the locking body at the intersection of the two undersurfaces.

The locking formation of the locking body may form a rib which is adapted to be received within the locking formation of the rail which may comprise a recess in the bottom wall.

The locking body may include a raised protrusion which projects through a cut-out or opening in the biasing means, movement of the protrusion within the opening in the biasing means limiting the range of movement of the locking body relative to the biasing means. This may be a cut-out or opening in a leaf spring.

The first (fixed) end of the spring may be connected to a slider adapted to slide along the guide rail, the locking body being free to move relative to the spring to move from the first condition to the second condition.

The catch mechanism may be adapted to be moved from its first condition to its second condition by sliding the locking body along the guide rail relative to the biasing means. This enables the end of the locking body to be moved into and out of engagement with the fixed end of the spring once the locking body has been pivoted into its first orientation against the force of the spring.

In accordance with a second aspect, the invention provides a window assembly incorporating a catch mechanism in accordance with the first aspect of the invention.

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

In the accompanying drawings:

Figure 1 is a view of a window hinge mechanism incorporating a catch mechanism of the present invention in a normal fully open condition; Figure 2 is a view of the mechanism adjusted to a cleaning mode; Figure 3 is an enlarged view of a normally-fixed link slider engaged in a guide rail of the mechanism; Figures 4A and 4B are longitudinal sectional views through the link slider and guide rail showing the slider in locked and released conditions respectively; Figures 5A, 5B and 5C are top plan, side elevation and bottom plan views of a locking plug of the link slider; Figure 6 is a section taken through the guide rail; Figure 7 is a side view, partly in section, of the restrictor catch mechanism comprising a second slider secured to a restrictor arm 6 and interlocked with a locking formation of the guide rail to prevent movement of the restrictor arm along the guide rail; Figure 8 is a plan view of the assembly shown in Figure 7; and Figures 9A to 9E show the restrictor catch in five different conditions in use.

A window hinge mechanism (Figures 1 and 2) incorporating a catch mechanism in accordance with the invention comprises first attachment means, in the form of a length of straight extruded channel, for securement to a window frame to provide a guide rail 10. Second attachment means in the form of a mounting bar 12 is adapted to be secured to a sash of an openable window. Linkage mechanism comprising two pivotally coupled scissor links 14,16 serves to couple together the guide rail 10 and the mounting bar 12 in the manner of a hinge. A first of the two links 14 is pivotally connected at one end to the mounting bar 12 and at its other end to a normally-fixed first link slider 18 engaged in the guide rail 10. The second of the scissor links 16 is also pivotally connected at its opposite ends to the mounting bar and the guide rail, but in this case by way respectively of a stud 20 which is free to move along a guide slot 22 in the mounting bar and by way of a second link slider 24 which is free to slide along the guide rail 10. The channel- form crosssection of the guide rail is shown in Figure 6, the two sliders being retained in the rail by means of opposed, inwardly directed, edge flanges 26,28 which are spaced from but overlie a bottom wall 30 of the rail. A hinge mechanism substantially as so far described is described in more detail in GB-A-2 304 148. It enables a window panel secured to the mounting bar 12 to be opened through substantially 90', an adjacent inner 1 7 end of the guide rail 10 lying close to the plane of the panel to maximise the emergency egress opening formed when the window is fully open.

The hinge mechanism comprises. also a restrictor which can be utilised to restrict the opening of the window, for example for child safety reasons. As seen in Figures 1, 2, 7 and 8, the restrictor comprises an arm 32 which is pivotally connected at one end to the stud 20 sliding on the sash mounting bar 12 and at its other end to a slider 34 which is freely movable along the guide rail 10 on the opposite side of the normally fixed first link slider 18 from the second link slider 24. When the window is fully closed, the second link slider 24 is positioned adjacent to the inner end of the guide rail and the restrictor slider 34 is positioned adjacent to the opposite end, the two sliders moving towards one another to abut the fixed first link slider 18 when the window is fully opened. A catch mechanism 36 is coupled to the restrictor slider 34 and is itself retained to slide in the guide rail, being arranged to become engaged with a locking formation providing a slot 38 (Figure 1) cut out of the bottom wall 30 of the guide rail, when opening is to be restricted. The construction and operation of the restrictor catch is described in more detail hereinafter.

The restrictor can be utilised also in adjusting the hinge mechanism to a cleaning mode in which cleaning of outer surfaces of the window panel is facilitated. As hereinbefore referred to, when the window is ordinarily fully open (as shown in Figure 1) the plane of the panel lies close to the inner end of the guide rail. The inner end of the rail would o rdinarily be fitted closely up to a corner of a rectangular window frame. This can leave very little space between the frame and the window panel for accessing the outer surfaces of the panel. To improve access, locking means 40 (Figure 3) of the first link slider can be released to permit the two link sliders 18,24 to be moved along the guide rail away from the 8 inner end of the rail, so bearing the mounting bar 12 (and the window panel thereon) a distance towards the middle of the window frame.

Starting from a closed condition of the window, such movement of the mechanism is achieved by first engaging the restrictor catch (which so permits only a very limited degree of opening). With the first link slider 18 released, further opening movement of the window hinge mechanism is then necessarily accompanied by movement of both link sliders 18, 24 along the guide rail 10 away from the inner end and towards the restrictor slider 34 (held stationary in the rail by the catch mechanism). The condition illustrated by Figure 2 is so achieved, in which the plane of the window panel on the mounting bar 12 is well spaced from the inner end of the guide rail and, correspondingly, the adjacent window frame.

is The arrangement of the locking means 40 of the first link slider 18 is illustrated by Figures 3, 4 and 5, the slider construction otherwise being similar to that described in GB-A-2 304 148. The locking means comprises a moulded plastics locking member in the form of a plug (Figures 5A, 5B and 5C) which comprises a cylindrical top portion which forms an operating head 44. An end face 46 of the head is exposed through a body of the slider and formed to provide a screwdriver slot 48, the head being freely rotatable in a circular opening 50 in a top plate 52 of the slider.

A bottom portion of the locking plug provides a locking element in the form of a locking bar 54 having somewhat rounded end faces 56, 58.

A generally oblong intermediate portion of the plug forms two 30 camming elements in the form of wings 62, 64 which project outwardly 9 beyond the circumference of the head 44, upper surfaces of each wing forming an inclined ramp surface 66 which leads up to a land surface 68 which lies in a plane perpendicular to the axis of the plug head.

The locking means 40 comprises also a leaf spring 70 (Figures 4A and 4B) which is arranged to act between the bottom wall 30 of the guide rail 10 and undersurfaces 72 of the wings of the locking plug. The spring urges the plug upwardly, which is to say outwardly of the channel, away from the bottom wall 30 of the guide rail.

In the released condition of the slider 18 with the locking means 40 unlocked (Figure 4B) the locking plug is held in a raised position by the spring 70, the intermediate portion of the plug lying between the opposed edge flanges 26, 28 of the guide rail. In this condition, the locking bar 54 is positioned above the surface of the bottom wall 30 of the guide rail and the slider is free to move along the rail.

A locking formation providing a square slot 74 (see also Figure 2) is formed in the bottom wall 30 at the position in which the slider 18 is to be fixed in normal operation of the hinge mechanism. The length of the square slot is the same (through allowing for suitable tolerances) as the length of the locking bar 54. In order to lock the locking means, and so fix the slider in the guide rail, the locking plug can be depressed and rotated through 90' by means of a screwdriver engaged in the head slot 48, the locking bar 54 so becoming engaged in the recess formed by the slot 74, the bar lying longitudinally of the rail between side faces of the slot. The bar is maintained in the slot against the upwards pressure of the spring 70 by engagement of the land surfaces 68 of the plug wings 62, 64 beneath the edge flanges 26, 28 of the rail, the ramp surfaces 66 easing the introduction of the wings beneath the edge flanges as the plug is rotated. Unlocking can be achieved by a further 90' rotation of the locking plug. The ramp surfaces may themselves serve to push the plug downwardly in to the channel as it is rotated.

The arrangement enables the slider to be returned with precision to the required location along the guide rail in which it is to be fixed for normal use of the hinge mecharism. Provided the slider is positioned in its unlocked condition with the locking bar over the slot 74 (at whatever position along the length of the slot the transversely - extending bar becomes inserted) the rounded end faces 56, 58 ensure that the bar can be rotated until it lies longitudinally of the rail within the slot, the slider so becoming drawn into the required operative position by a camming action occurring between the bar and the walls of the slot. This mechanism avoids the need for very precise manual location of the slider in returning it to its normal operational location.

The construction and operation of the restrictor catch will now be described in more detail with reference to Figures 7, 8 and 9A-E of the drawings. With reference initially to Figures 7 and 8 and to Figure 9A (which for convenience illustrates the arrangement to a larger scale) the catch mechanism 36 comprises a unitary locking body 76 and biasing means comprising a leaf spring 78. The leaf spring serves to couple the body to the restrictor slider 34, being connected at its inner end to the slider (Figures 7 and 8) and thereby secured at that end heightwise relative to the rail.

The leaf spring comprises a broader inner end portion 80 of which lateral margins 81, 83 lie beneath the edge flanges 26, 28 of the guide rail. An outer end portion 82 of the spring is narrower than the spacing between the edge flanges and bears down on the locking body 76, there 11 being a rectangular opening 84 in the spring whereby the spring surrounds an exposed actuating block 86 of the body which protrudes upwardly from the rail through the opening.

The locking body comprises undersurfaces which lie in two planes which are inclined to one another: as indicated in Figure 9A, undersurfaces 88 of an outer end portion of the body lie in a first plane and undersurfaces 90 of an inner end portion lie in a second plane which is inclined to the first, a fulcrum being formed where the undersurfaces meet (at a position indicated by the reference 92). The outer end portion 82 of the spring 78 bears against the outer end portion of the locking body on the opposite side of the fulcrum 92 from the restrictor slider 34 (urging an anti-clockwise rotation of the body as viewed in Figures 7 and 9). A locking nib 94 projecting downwardly from the undersurfaces 88 of the outer end portion of the body is arranged for engagement in the slot 38 to prevent movement of the catch mechanism along the guide rail 10.

The slot 84 in the spring 78 is rather longer than the distance (measured longitudinally of the rail) between inner end and outer end faces 96, 98 of the actuating block 86. The block can accordingly be moved relative to the spring in the direction longitudinally of the rail. Movement of the spring outwardly relative to the block is limited by an upstanding outer end block 100 of the locking body in conditions in which the inner end face 96 is not engaged.

Lastly, as regards the construction of the locking body, a tab 102 projects from the actuating block 86 in the inwards direction along the rail (i.e. towards the restrictor slider 34) from a position immediately beneath the inner end face 96. The distance between the outer end face 98 of the 12 block and the free end of the projecting tab 102 is less than the length of the slot 84 in the spring.

Use of the catch mechanism will now be described. Figures 7, 8 and 9A show the mechanism in the condition in which it would ordinarily be when the window was fully closed, the outer end of the leaf spring 78 being close to the end block 100 of the locking body, the outer end undersurfaces 88 of the body lying against the bottom wall 30 of the guide rail 10, and the locking nib 94 being engaged in the slot 38 in the rail to arrest the slider against movement along the rail.

Upon an attempt being made to open the window, the restrictor arm 32 draws the restrictor slider 34 inwardly along the rail until the attached leaf spring 78 (moving relative to the locking body 76) engages the outer end face 98 of the actuating block 86. This condition is shown in Figure 9B. The locking nib 94 remaining in engagement in the slot 38 in the rail, further opening movement of the window is prevented. [The fixed link slider 18 may now be released and the window moved to cleaning position if required].

To release the catch mechanism to permit further normal opening of the window, the actuating block 86 is manually depressed to rock the locking body about the fulcrum 92 against the action of the spring 78. The locking nib 94 so becomes lifted out of the rail slot 38, permitting the catch mechanism to be moved inwardly along the rail as the window is pushed open. These conditions are shown successively in Figures 9C and 9D.

In the conditions of Figure 9D, the locking body can slide along the bottom wall 30 of the guide rail in either direction, as the degree of 13 opening of the window is varied. Should the window become sufficiently closed, the leaf spring 78 will act automatically to re-engage the locking nib 94 with the rail slot 38. It is to be noted that this re- engagement occurs with the leaf spring abutting the outer end face 98 of the actuating block 86, and so still separated from the end block 100, the window having been returned to its restricted opening condition. In this condition, which is represented also in Figure 3, the locking means 40 of the first link slider 18 can be accessed for locking or unlocking the slider. Upon fully closing the window, the leaf spring 78 becomes moved relative to the locking body (towards the end block 100) until the condition shown in Figure 9A is resumed.

Figure 9E illustrates how the catch mechanism can be adjusted so as to prevent the locking nib 94 from reengaging with the guide rail.

This condition is arrived at by sliding the locking body 76 inwardly relative to the leaf spring 78 when held fully depressed about the fulcrum 92, causing the tab 102 to become inserted beneath the inner end portion 80 of the spring adjacent to the opening 84. The locking nib is so held, against the pressure of the spring, above the level of the bottom wall 30 of the rail. The restrictor can so be disabled should it not be required.

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Claims

A catch mechanism for a slider which is mounted for movement along a guide rail, the mechanism being adjustable between a first condition in which the slider in movement along the rail is arranged to become arrested automatically by engagement with a locking formation at a locking position on the rail and a second condition in which the slider is arranged not to become so arrested, the slider comprising a locking body and biasing means arranged in the first condition but not in the second condition to cause a locking formation of the body to become interengaged with the locking formation of the rail when the slider becomes moved to the locking position.
2. A catch mechanism according to claim 1 in which the locking body is pivotable forwardly and rearwardly in the direction of the length of the guide rail between a first orientation in which its locking formation is raised and out of engagement with the locking formation on the rail when in the locking position and a second orientation in which its locking formation is lowered and in engagement with the locking formation in the locking position.
3. A catch mechanism according to claim 2 in which the biasing means comprises a leaf spring which at a first end is secured heightwise relative to the rail and which at its other end is arranged to bear down on the locking body to urge the body to pivot into its second orientation.
4. A catch mechanism according to claim 3 in which in the first condition of the catch mechanism the locking body is free to pivot between its first and second orientations, so that the slider can be moved along the rail with the body in its first orientation but will become arrested upon returning to the locking position owing to the spring causing the body to rock into its second orientation.
5. A catch mechanism according to any one of claims 3 or 4 in which in its second condition the locking body is held in a third orientation and prevented from moving to its second orientation by engagement of an end portion of the locking body with the first end of the spring.
6. A catch mechanism according to claim 5 in which the third orientation is substantially the same as the first orientation.
7. A catch mechanism according to any one of claim 3 to 6 in which the guide rail comprises a channel having an upwardly facing bottom wall and side walls supporting opposed inwardly directed edge flanges which are spaced from but overlie the bottom wall and the fixed end of the spring lies at least partially below the.edge flanges of the guide rail.
8. A catch mechanism according to claim 7 in which in its second condition, the end portion of the locking body is held between the bottom wall of the guide rail and the fixed end of the spring.
9. A catch mechanism according to any preceding claim in which the locking body has at least two undersurfaces which lie in two planes which are inclined to one another.
10. A catch mechanism according to claim 9 in which movement from the first orientation to the second orientation is by pivoting about the portion of the locking body at the intersection of the two undersurfaces.

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11. A catch mechanism according to any preceding claim in which the locking formation of the locking body forms a rib which is adapted to be received within the locking formation of the rail which comprises a recess in the bottom wall.
12. A catch mechanism according to any preceding claim in which the locking body includes a raised protrusion which projects through a cutout or opening in the biasing means, movement of the protrusion within the opening in the biasing means limiting the range of movement of the 10 locking body relative to the biasing means.
13. A catch mechanism according to any preceding claim adapted to be moved from its first condition to its second condition by sliding the locking body along the rail relative to the biasing means.
14. A hinge assembly incorporating a catch mechanism according to any preceding claim.
15. A catch mechanism substantially as described herein with reference 20 to the accompanying drawings.