GB2276914A

GB2276914A - Movable pivot joint

Info

Publication number: GB2276914A
Application number: GB9405489A
Authority: GB
Inventors: Ronald Percival Davis
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-03-19
Filing date: 1994-03-21
Publication date: 1994-10-12
Also published as: GB9405489D0

Abstract

A movable pivot joint between and a frame plate 1 and a link 3 of a window stay, can be released to allow the pivot point of the link to move, so that the window can be opened widely. For emergency egress for example. The joint comprises a slide component (2, Fig. 2) retained by the frame mounting member 1 which can move from a normally fixed position along the mounting member. A pivot connection 4 connects the link of the window stay to the slide component, and a manually releasable locking lever 6 holds the slide component in its normally fixed position but can be released to allow the pivot joint to be moved along the frame plate. <IMAGE>

Description

A MOVABLE PIVOT JOINT FIELD OF INVENTION My present invention comprises a movable pivot joint for a window stay.

BACKGROUND A window stay generally consists of a frame plate which is fixed to the window frame, a sash plate which is fixed to the window sash, and at least two arms between the frame plate and sash plate. Each of the arms is connected to the frame plate and the sash plate by a pivot joint. In a four bar window stay for example, the top or short arm is connected to the sash plate at one end by a friction pivot joint and to the frame plate at its other end by a friction pivot joint, as is the bottom or long arm. These pivot joints are fixed e.g. the point at which the bottom arm is pivotally connected to the frame plate is fixed at a set point on the frame plate.

SUMMARY OF INVENTION The present invention provides an improved or at least alternative form of pivot joint where the position of the pivot joint may be moved relative to the frame plate (or sash plate) of a window stay.

In broad terms the invention comprises a movable pivot joint between an arm and a frame plate (or a sash plate) of a window stay, comprising a slide component retained by the frame plate for sliding movement of the slide component from a home position along the frame plate, a pivot connection connecting the arm of the window stay to the slide component, and manually releasable locking means normally holding the slide component in its home position.

Where the movable pivot joint of the invention forms the long arm-frame plate pivot joint of a window stay such as a four bar window stay for example, this enables the window to be opened more widely than is possible during normal operation of the stay, in an emergency for example. When the window sash is fully opened, the locking means of the movable pivot joint may then be released and when the window sash is pushed further the long arm-frame plate pivot joint will slide along the frame plate towards the short arm-frame plate pivot joint, allowing the sash to open beyond its normally fully open position. This makes escape from the window easier in an emergency for example.

DESCRIPTION OF DRAWINGS A preferred form of the movable pivot joint of the invention is illustrated, by way of example, in the accompanying drawings wherein: Fig. 1 is a view of the preferred form movable pivot joint, between the long arm and frame plate of a window stay, Fig. 2 is a cross-sectional view of the preferred form movable pivot joint, along line I-I in Fig. 1, Fig. 3 is a cross-sectional view of the preferred form movable pivot joint along line II-II in Fig. 1, and Figs 4 and 5 schematically show the operation of the movable pivot joint of the invention to enable a window to be opened beyond its normally fully opened position in an emergency.

DESCRIPTION OF PREFERRED EMBODIMENTS In Fig. 1 reference numeral 1 indicates the frame mounting member or frame plate of a window stay. In the preferred form movable pivot joint the frame plate is channel shaped in cross-section, as shown in Fig. 3. A slide component 2, most suitably formed of a plastic material, is captured within the interior of the channel shaped frame plate as shown in Fig.

3. The slide 2 can slide along the frame plate 1 within its channel shaped profile, in the direction of arrow A. The edge parts la of the frame plate on either side extend partly over the slide 2 so that it is captured as described. However, the slide component 2 may be slidably mounted to the frame plate 1 in any other sliding arrangement.

An arm 3 of a window stay, in this case the long arm, is pivotally connected to the slide 2. Preferably an annular shoulder or upstand 2a projects from the slide 2 and through a hole in the end of the arm 3 so that the arm 3 is located about the preferably plastic annular upstand. A cap screw 4 having a wide head is screwed into the interior of the annular shoulder to hold the arm in position and apply friction to the joint between the arm and the slide. This type of joint between the arm and slide 2 is preferred but the connection may comprise any other form of pivot joint or friction pivot joint as is known in the art.

A pillar 5 projects from the bottom of the base plate as shown. The pillar 5 may be hollow so that one of the fixing screws which fixes the stay to the window frame passes through the pillar. A locking lever 6 is also pivotally mounted to the slide 2. A hole in one end of the locking lever engages over the annular shoulder of the slide below the arm 3 as shown in Fig.

2. The locking lever can pivot between the locked position shown in hard outline in Fig. 1 when a cut-out 6b in the side of the locking lever engages the pillar 5 to hold the slide in its home position, and the unlocked position shown in phantom outline.

The other end of the locking lever is suitably shaped as an operating button for thumb pressure at 6a. When the locking lever 6 is moved to its unlocked position (phantom outline in Fig. 1), the slide 2 carrying the long arm to frame plate pivot joint can slide along the frame plate, and back again. If the movable pivot joint has been operated to open the window beyond its normally fully open position for some reason, when the window is next closed by pulling in on the sash, the movable pivot joint will automatically slide back to its home position and when the sash closes it will push the locking lever back into its locked position with the locking lever engaging the pillar.

Figs. 4 and 5 schematically show operation of a four bar window stay wherein the movable pivot joint of the invention forms the bottom arm-frame plate pivot joint. In Fig. 4 the window sash WS is shown open to its normally fully open position.

WF indicates the window frame. At this point the movable pivot joint indicated at MPJ may be unlocked to allow the bottom armframe plate pivot joint to slide towards the top arm-frame plate pivot joint so that the window sash can be opened further to the position shown in Fig. 5.

The slide 2 may be slidably retained by the frame plate 1 by arrangements other than as shown in the drawings. Any suitable form of pivot joint may be used. Locking means other than the locking lever and pillar may be used, the arrangement shown in the drawings being one preferred arrangement.

The foregoing describes my invention including a preferred form thereof. Alterations and modifications as will be obvious to those skilled in the art are intended to be incorporated within the scope hereof as defined in the following claims.

Claims

1. A movable pivot joint between and a frame mounting member (or a sash mounting member) of a window stay, comprising a slide component retained by the frame mounting member for sliding movement of the slide component from a home position along the mounting member, a pivot connection connecting the arm of the window stay to the slide component, and manually releasable locking means normally holding the slide component in its home position.

2. A movable pivot joint as claimed in claim 1, wherein the manually releasable locking means comprises a locking lever also pivotally mounted to the slide component and means fixedly associated with the frame mounting member which is engaged by the locking lever when the pivot joint is locked in its true position and from which the locking lever may be disengaged to allow movement of the pivot joint.

3. A movable pivot joint as claimed in claim 2, wherein the means engaged by the locking lever comprises a pillar projecting from the frame mounting member adjacent the home position of the pivot joint.

4. A movable pivot joint as claimed in claim 3, wherein the locking lever includes a cut out in the locking lever open to one side of the locking lever to engage the pillar when the pivot joint is locked in its home position.

5. A movable pivot joint as claimed in any one of claims 2 to 4, wherein the end of the locking lever opposite the pivot connection of the locking lever to the slide component is formed with a thumb or finger grip portion.

6. A movable pivot joint as claimed in any one of the preceding claims wherein the frame mounting member of the window stay has a channel shaped profile in transverse cross-section and edge parts of the frame mounting member on either longitudinal side of the frame mounting member engage in grooves on either side of the slide component to capture the slide component for sliding movement on the frame mounting member.

7. A movable pivot joint as claimed in any one of claims 2 to 6, wherein the pivot connection between the arm of the window stay and the locking lever and the slide component comprises an annular shoulder or upstand projecting from the slide and co-axially through a hole in the end of the locking lever and a hole in the end of the arm so that the locking lever and the arm are located about the annular upstand, and a headed fixing means fixed in the interior of the annular upstand to hold the locking lever and arm in position and apply friction to the joint.

8. A movable pivot joint substantially as herein described with reference to the accompanying drawings.