GB2319559A - Sliding catch. - Google Patents

Abstract

A stay catch assembly, slidable along a guide rail (12) secured to a window frame, with an arm (14, Figure 4) connecting the assembly to a window sash. Locking body 34 comprises a locking element (42) engageable with a locking slot (46) on the rail, urged by a leaf spring (56). Spring 56 also provides a securing aperture to hold connecting arm 14 (see Figure 11). A plastics slider with cross-pieces (28, 30) surrounds the locking body and frictionally engages the side walls of rail 12. To release the catch, movement of the assembly in a first direction (right to left on Figure) causes the camming face 48 to lift the locking element 42 out of slot 46 (see Figure 2). Reversing the direction of movement of the assembly causes body 34 to move relative to the slider (22) until cross-piece 30 is positioned below the body part 40 to prevent element 42 locking back into slot 46 (see Figure 3). Subsequent movement in the first direction releases body 34 from member 30, allowing the catch to be locked once more.

Description

This invention is concerned with improvements in or relating to sliding catches generally, but especially stay catches such as may be used, for example, to support an opening window releasably in an open position.

For example to support a top hung window (i.e. swinging about a horizontal axis), a stay may be employed which comprises an arm extending between the window sash and a side member of a surrounding window frame. A bottom end of the arm may be supported to move along a rail of the side member and, by means of some suitable catch arrangement, enabled to engage with the rail at one or more positions along the rail. The catch permits the arm to be released from locking engagement with the rail when required, either to close the window or for movement of the arm to another locking position on the rail.

It is an object of the present invention to provide an improved sliding catch mechanism.

In one of its aspects, the invention provides a sliding catch mechanism comprising a guide rail and a catch assembly retained for movement along the rail, the catch assembly comprising a locking body which is arranged to become interengaged with locking means of the rail at a locking position along the rail to prevent movement of the assembly in a first direction along the rail, a spring arranged to urge the body into interengagement with the locking means when the body is positioned at the locking position, catch-releasing means whereby the body is arranged to become disengaged from the locking means against the action of the spring in a movement of the catch assembly away from the locking position in a second direction along the rail opposite to said first direction, and catch-restraining means arranged to prevent re-engagement of the body with the locking means following a subsequent reversal of movement of the catch assembly taking the assembly in said first direction through the locking position.

The catch-releasing means may comprise a portion of the locking body and/or a portion of the guide rail which presents a camming surface which serves to lift the body out of engagement with the locking means of the rail in movement of the catch assembly from the locking position in the second direction. The locking means may form a recess or aperture in the rail into which a protrusion of the locking body becomes engaged to prevent movement of the catch assembly in the first direction along the rail.

The catch-restraining means can comprise a restraining element of the assembly which is movable longitudinally relative to the locking body and is arranged to become positioned beneath the locking body on movement of the body in the first direction upon the reversal of movement of the assembly; the element when so positioned beneath the body prevents re-engagement of the locking body with the locking means as the body moves through the locking position.

In a preferred construction, the restraining means comprises a slider which is free to move longitudinally relative to the locking body between an advanced position, in which a restraining element formed by the slider is so positioned relative to the body as to prevent movement of the locking body into engagement with the locking means of the rail, and a retracted position in which the restraining element is held clear of the locking body. Movement of the slider may be resisted frictionally by the rail so that movement of the locking body in the second direction results in the slider assuming its retracted position on the locking body, and reversal of the direction of movement of the body to movement in the first direction results in the slider assuming its advanced position on the body.

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

In the accompanying drawings: Figures 1, 2 and 3 are side views of a stay catch mechanism in three different stages of operation; Figure 4 is a plan view of the mechanism, with a stay arm shown attached; Figure 5 shows a transverse cross-section through a guide rail of the mechanism; Figure 6 is a top plan view of a slider of the mechanism; Figure 7 is a view of the slider in section taken on line Vil-Vil of Figure 6; Figure 8 is a side view of the slider; Figures 9 and 10 are side and underneath plan views of a locking body of the mechanism; and Figure 11 is a plan view of a leaf spring of the mechanism.

A stay catch mechanism (Figures 1 to 4) comprises a catch assembly 10 which is retained to slide along a guide rail 12; the rail may be secured to an upright side member of a window frame. A stay arm 14 (Figure 4) connects the mechanism to a window sash, the arm being pivotally secured to the catch assembly, to support the window in an open position.

The cross-section of extruded metal section forming the guide rail 12 is shown in Figure 5. The section forms a channel 16 and comprises two oppositely-projecting edge flanges 18,20 which overlie edge portions of the channel.

The catch assembly comprises a plastics slider 22, shown in detail in Figures 6, 7 and 8. The slider is moulded in one piece of glass-filled nylon and comprises spaced side arms 24,26 which are connected at front and rear ends, respectively, by front and rear cross-pieces 28,30. In a relaxed condition of the slider, as shown in Figure 6, the side arms are outwardly bowed. Upon insertion into the channel 16 of the guide rail, the side arms become flexed resiliently inwards by side walls 19,21 of the channel, the arms lying beneath the edge flanges 18,20 of the rail.

Pressure of the channel side walls against the side arms affords some frictional resistance to movement of the slider along the rail. The rear cross-piece 30 of the slider constitutes a catch-restraining element of the assembly.

The catch assembly comprises also a metal locking body 32, shown in detail in Figures 9 and 10. The body comprises a first portion forming an upper web 34 which is of rectangular form in plan and is dimensioned widthwise to fit as an easy sliding fit between the opposed edge flanges 18,20 of the rail. A second portion of the body, positioned centrally beneath the upper web 34, forms a narrower rail-engaging runner 36 arranged to lie against a flat bottom wall 38 of the channel (Figure 5). A third portion of the locking body forms a tail web 40 which is of a similar width to the upper web 34 and projects rearwardly from the runner.

The runner 36 comprises a lower rear-end portion 42 which protrudes below a flat bottom surface 44 of the runner. The protruding portion constitutes a locking element which is shaped to engage in a rectangular locking slot 46 in the bottom wall 38 of the guide rail (Figure 1). A front surface 48 of the locking element 42 is inclined so as to form a camming surface which will cause the locking element to be lifted out of the locking slot 46 upon the locking body being slid forwardly along the guide rail.

As seen in Figures 1 and 4, the slider 22 extends around the runner 36 and the tail web 40 within the rail channel 16, the length between a front end face 50 of the runner 36 and a rear end face 52 of the tail web 40 being just a little less than the distance between the front and rear cross-pieces 28,30 of the slider.

The catch assembly comprises also a thin metal plate forming a leaf spring 54 which is shown in detail in Figure 11. The plate comprises a front end portion 56 which is of similar width to the channel 16 in the guide rail, so as to fit beneath the edge flanges 18,20 of the rail as an easy sliding fit. An aperture 57 in the front end portion enables the stay arm 14 to be secured to the plate, and so to the catch assembly. A narrower rear end portion 58 of the plate is of similar width to the upper web 34 of the locking body, so as to fit easily between the edge flanges 18,20 of the rail, and is formed with a central rectangular aperture 60 which enables it to be fitted over the runner 36 of the locking body beneath the upper web 34. The plate is located on the body between a front end notch 62 of the runner and a rear end mound 64 formed above the tail web 40, the plate being located in the notch and just fitting over the mound. A tail portion 66 of the plate fits snugly in a recess formed between the mound 64 and a raised end wall 68 of the tail web.

Reverting to Figures 6,7 and 8, a forward portion 70 of the slider is of reduced thickness to accommodate the thickness of the overlying front end portion 56 of the leaf spring. Side recesses 72,74 in the forward portion 70 accommodate rear edge portions 76,78 of the front end portion of the leaf spring (Figure 11) which are turned down in order to avoid snagging on the underside of the rail edge flanges 18,20.

In Figure 1 the catch assembly is shown with the locking element 42 interengaged with the guide rail to prevent rearwards movement (left to right in Figures 1 to 4) of the assembly along the rail.

In a forwards movement of the assembly (Figure 2), the locking element can be caused to be lifted out of the locking slot 46 in the rail by engagement of the inclined camming surface 48 against a front edge of the rail bounding the slot 46. The locking body becomes lifted at its rear end against the action of the spring plate 54 which remains engaged (at its front end) beneath the edge flanges 18,20 of the rail. The slider 22 moves forwards with the locking body owing to its engagement with the front Upon reversing the direction of movement of the assembly (Figure 3) the locking body moves rearwardly relative to the slider, since the tail web 40 has been raised above the level of the rear cross-piece 30 by the lifting of the rear end of the locking body. The tail web so moves over the rear cross-piece, which so acts as a catch-restraining element which prevents the locking element from dropping back into the locking slot 46 as the assembly moves rearwards over the slot. Once the rear cross-piece 30 has abutted a rear face 70 of the locking element 42 beneath the tail web 40, the slider is pushed along rearwards by the locking body.

Upon a further reversal of the movement, to move the assembly forwards, the locking body moves forwards relative to the slider until the locking element 42 moves off the restraining element 30 and becomes again free to drop into the locking slot 46, when encountered.

Claims (7)

1. A sliding catch mechanism comprising a guide rail and a catch

assembly retained for movement along the rail, the catch assembly comprising a locking body which is arranged to become interengaged with locking means of the rail at a locking position along the rail to prevent movement of the assembly in a first direction along the rail, a spring arranged to urge the body into interengagement with the locking means when the body is positioned at the locking position, catch-releasing means whereby the body is arranged to become disengaged from the locking means against the action of the spring in a movement of the catch assembly away from the locking position in a second direction along the rail opposite to said first direction, and catch-restraining means arranged to prevent re-engagement of the body with the locking means following a subsequent reversal of movement of the catch assembly taking the assembly in said first direction through the locking position.

2. A mechanism according to claim 1 in which the catch-releasing means presents a camming surface which serves to cause the body to become lifted out of engagement with the locking means in movement of the catch assembly from the locking position in said second direction.

3. A mechanism according to either of claims 1 and 2 in which the locking means forms a recess in the rail into which a protrusion of the locking body becomes engaged to prevent movement of the catch assembly in the first direction along the rail.

4. A mechanism according to any one of claims 1 to 3 in which the catch-restraining means comprises a restraining element of the assembly which is movable longitudinally relative to the locking body and is arranged to become positioned beneath the locking body on movement of the body in said first direction upon said reversal of movement of the assembly, whereby to prevent re-engagement of the locking body with the locking means as the body moves through the locking position.

5. A mechanism according to claim 4 in which the restraining means comprises a slider which is free to move longitudinally relative to the locking body between an advanced position, in which a restraining element formed by the slider is so positioned relative to the body as to prevent movement of the locking body into engagement with the locking means of the rail, and a retracted position in which the restraining element is held clear of the locking body.

6. A mechanism according to claim 5 in which movement of the slider is resisted frictionally by the rail so that movement of the locking body in said second direction results in the slider assuming its retracted position on the locking body, and reversal of the direction of movement of the body to movement in said first direction results in the slider assuming its advanced position on the body.

7. A sliding catch mechanism substantially as hereinbefore described with reference to the accompanying drawings.