GB2458706A

GB2458706A - Slide Shoe for a Sash Window

Info

Publication number: GB2458706A
Application number: GB0805744A
Authority: GB
Inventors: Michael Derham
Original assignee: Mighton Products Ltd
Current assignee: Mighton Products Ltd
Priority date: 2008-03-28
Filing date: 2008-03-28
Publication date: 2009-09-30
Anticipated expiration: 2028-03-28
Also published as: GB0805744D0; GB2458706B

Abstract

A slide shoe 14 has brake blocks 20 which are pushed outwards to brake the shoe in a track 16 of a window frame 10, when the window sash 12 is pivoted out of the plane of the frame. The brake blocks have resilient pads 50 which come into contact with the frame surfaces and generate a frictional braking force, and metal edges 48 which come into contact with the frame surfaces after the resilient pads have compressed against the surface to dig into the track surface to enhance the braking action of the shoe in the track.

Description

Slide Shoe for a Sash Window This invention relates to a slide shoe for a sash window, which enables a window sash to slide vertically in a window frame and to pivot out of the plane of the frame, when this is desired.

Sash windows are conventionally mounted within a window frame and are designed to move vertically within the frame to open and close the window. The weight of the sashes (of which there are usually two) is counterbalanced by sash weights or by spring balances housed in the vertical sides (stiles) of the frame. The counterbalancing enables the sashes to be moved up and down with relatively little effort, and ensures that they stay in any position to which they are put.

*:*:* 15 In windows with plastic (UPVC) frames, the stiles are extruded sections with channels in them for containing the balances (which are more common than sash weights in UPVC windows). It is known to connect the balances to the sash through a slide shoe which runs in a channel in the frame and to which the balances on the one hand and the sash on the other hand are both connected.

Usually the shoe is connected to the bottom edge of the sash. S...

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* According to the invention, there is provided a slide shoe comprising a body adapted to fit within and to slide along a track in a window frame, * a pivot support mounted fOr rotation in th body, the pivot support having a socket for receiving a peg mounted on a window sash, the peg and the socket being non-round so that rotation of the sash about the axis of the peg causes the pivot support to rotate in the body, and * at least one brake pad mounted in the shoe and extendable from the shoe to grip a surface of the window frame track, the extension of the pad being actuated by rotation of the pivot support, the or each pad having a braking surface mounted in a metal carrier, the braking surface normally lying proud of the metal camer but being adapted to compress when extended into contact with the frame, so that part of the metal carrier makes contact with the frame surface.

The pivot support preferably carries a cam surface such that the brake pad or brake pads are cammed outwards when the pivot support rotates.

There are preferably two pads mounted opposite one another such that, when the window and its peg rotate, the pivot support rotates and presses the pads outwards so that the pads engage opposed faces of the track.

The metal carriers for the brake pads preferably have frame-engaging surfaces above and blow the resilient braking surface. The frame engaging surfaces **,.*. 15 may have a tooth or teeth so that they bite into the material of the frame to augment the frictional grip of the resilient surface on the frame. S...

: The shoe may also include a mounting point for a spring balance, and means for adjusting the tension of the balance, as described in our UK Patent GB 2 398097.. S...

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* The invention will now be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a slide shoe in accordance with the invention in conjunction with a window sash and a window frame; Figure 2 is a front view of the shoe with brake pads retracted; Figure 3 is a rear view of the shoe with brake pads extended; Figure 4 is a view, on a larger scale, of the pivot support, shown separated from the shoe; Figure 4a is a section through the pivot support on the line IVa-IVa; and Figure 5 is a perspective view of selected components of the shoe, with the shoe body omitted.

Figure 1 shows a portion of a window frame stile at 10 (partly cut-away), a corner of a window sash at 12 and a slide shoe 14. The shoe 14 is designed to fit closely in a track 16 of the frame 14 and to slide freely along the track. The window has a projecting peg 18 mounted at its bottom edge, to connect to the shoe 14 as will be described below.

Figure 1 shows one side of the window and frame; the same structure will be S...

provided on the opposite side of the window frame.

The shoe 14 has brake blocks 20 which, when extended, grip against the surface 22a and 22b of the frame 10, to lock the shoe and therefore the S...

window, against vertical movement in the frame.

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The shoe also has a mounting point 24 to which a spring balance (not shown in the figures) will be attached. ------In use, the window 12 normally lies in the plane of the window frame 10 and can be slid up and down in the frame to open or close the window. The weight of the sash is balanced by tension in the spring balances on opposite sides of the frame, so that the window can be raised or lowered with relatively little force, and the spring balance tension will hold the window in any position to which it is put.

As will be seen, the shoe 14 is located at the bottom edge of the window. At the top edge, the window has a device such as a retractable finger which normally runs in the track 16 and maintains the window in a vertical plane. However if it is desired to tilt the window sash out of the vertical plane, the finger is retracted from the track, so that the sash can pivot about the axis of the peg 18. This enables the window to be cleaned on both sides, and it may also be possible to completely remove the sash from the frame, for example if access is required to pass furniture into a building through an (empty) window frame.

The shoe 14 comprises a body 26 formed as a plastics moulding. Mounted in the body 26 are a pivot support 28, brake blocks 20, the spring balance ***. 15 attachment point 24, an adjustment mechanism 30 for the spring balance *..... adjustment and two leaf springs 52. S...

: The pivot support 28 is shown apart from the body, in Figure 4. The support has a backing disc 34, a cam shank 36 (seen in cross-section in Figure 4a) and a socket 38. The socket is designed to allow the window peg 18 to drop into the socket. As the cross-sectional shape of the peg 18 and of the socket 38 are * both rectangular1 tilting of the widow sash 12 about the axis of the peg 18 will result in the pivot shoe rotating in the body 14.

The support 28 fits into a circular recess in the body 26, from the back, and will be held in place when the shoe is fitted in the track because there will be no room for it to move back out from the body. On the front of the body is a collar 40, moulded as part of the body. The collar has a mouth 42 to guide the peg 18 into the socket 38, this being done when the sash 12 is positioned at right angles to the plane of the frame 10, when the open edge of the socket 38 will face uppermost and the peg can drop into it.

As will be apparent from Figure 4 and Figure 4a, when the pivot support lies with the major axis of the socket horizontal, the narrow dimension "a" of the cam shaft 36 will be presented between the two brake blocks 20, and the brake blocks will be retracted by the springs 52 so that the shoe can move up and down in the frame. However when the pivot support is turned through 90, the wide dimension "b" of the cam shaft will be presented between the brake blocks and this will act against bearing surfaces 44 of the blocks and push the blocks outwards into frictional engagement with the surfaces 22a and 22b. The shoe will then be held in place in one position in the track, and this can be at any desired position along the length of the track.

*.,.. 15 The blocks 20 comprise pad carriers 46 of metal with hard rubber pads 50. The faces of the rubber pads 50, when not pressed against the track walls, are I...

slightly proud of upper and lower edges 48 of the pad carriers. However when S...

: the pads are extended, the rubber pads first come into contact with the track walls and compress as pressure is applied through rotation of the cam shaft 36.

***. 20 At some point, the degree of compression of the pads 50 is such that the edges * 48 come into contact with the track walls and bite into the track walls to S.....

* S supplement the frictional forces between the rubber pads and the walls. It is anticipated that the engagement between the metal pad carrier edges will result in a slight penetration of-the edges into-the track walls,-but not sufficient penetration to cause significant damage to or roughening of the track walls.

When the pivot support returns to its horizontal position, the pad carriers 46 will be retracted by leaf springs 52 so that the shoe is once again free to slide up and down in the track.

The leaf springs 52 serve a dual purpose. They bear against a reaction point 54 in the body 14. The lower ends of the springs bias the brake blocks 20 inwards, and the upper ends bias ratchet pawls 56 which form part of the spring balance adjustment mechanism (more details of which can be seen in UK Patent GB 2 398 097).

The shoe described here works automatically to brake the shoe in the track whenever the sash is pivoted out of the plane of the window frame, these being the times when the shoe needs to be held in position until the sash is pivoted back into line with the frame. In particular, if the sash is lifted out of the frame, at which point the weight of the sash is no longer present to act against the counterbalancing force of the spring balance or counterweight, the shoe will be held in position in the track with sufficient force to prevent the counterbalancing from driving the shoe along the track. *. * I **** S... *. SI

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Claims

Claims 1. A slide shoe for a sash window installation, the shoe comprising * a body adapted to fit within and to slide along a track in a window frame, * a pivot support mounted for rotation in the body, the pivot support having a socket for receiving a peg mounted on a window sash, the peg and the socket being non-round so that rotation of the sash about the axis of the peg causes the pivot support to rotate in the body, and * at least one brake block mounted in the shoe and extendable from the shoe to grip a surface of the window frame track, the extension of the block being actuated by rotation of the pivot support, the or each block having a braking surface mounted in a metal carrier, the braking surface normally lying proud of the metal carrier but being adapted to compress when extended into contact with the frame, so that part of the metal *:*::* 15 carrier makes contact with the frame surface. * * ****
2. A shoe as claimed in Claim 1, wherein the pivot support carries a cam **** : surface such that the brake block or brake blocks are cammed outwards when the pivot support rotates. * 20 S...
3. A shoe as claimed in Claim I or Claim 2, having two brake blocks S.....* S mounted opposite one another and movable in opposite directions on actuation to engage opposed faces of the track.
4. A shoe as claimed in any preceding claim, wherein the metal carriers for the brake blocks have frame-engaging surfaces above and below the resilient braking surface.
5. A shoe as claimed in Claim 4, wherein the frame engaging surfaces have a tooth or teeth so that they bite into the material of the frame to augment the frictional grip of the resilient surface on the frame.
6. A shoe as claimed in any preceding claim, including leaf springs to bias the brake blocks away from the track walls.
7. A shoe as claimed in any preceding claim, including a mounting point for a spring balance, and means for adjusting the tension of the balance.
8. A shoe as claimed in Claim 7 when dependent on Claim 6, wherein the spring also bias part of a spring balance adjustment mechanism.* * 15
9. A slide shoe for a sash window installation, substantially as herein described with reference to the accompanying drawings. **.* * **.* * * ****S S...S*.SSSSS S