GB2141169A - Removable fastener - Google Patents

Abstract

A removable fastener for use in attaching a secondary glazing panel to a primary frame has a shank entering a plug in the frame and a deformable head entering a slot in the frame member of the panel. The shank is pointed so that the panel with the fasteners installed may be pressed against the primary frame to mark the positions of holes to be drilled to receive the plugs. <IMAGE>

Description

SPECIFICATION Removable. fastener This invention relates to a removable fastener and to secondary double glazing panels in combination therewith.

Many proposals have been made for secur ing secondary double glazing panels to the frame of an existing window and it is desirable to provide easy to use, unobtrusive fasteners which do not require unsightly parts to be left in place in the primary window frame when the secondary panel is removed.

Since many secondary double glazing falls within the "do-it-yourself" market it is also desirable to provide a system that enables an unskilled amateur to position the panels accurately.

According to one aspect of the present invention there is provided a removable fastener comprising a socket to be disposed within a blind hole in a base and a plug having a shank to extend within the socket and a head for engagement with a member to be held against the base; the head having a deformable part enabling it to be inserted by movement in one direction in a re-entrant recess in the member but precluding removal therefrom by movement in the opposite direction; spring means between the shank and the head for engagement with the member externally of the recess to hold the head firmly within the latter and holding means engageable between the shank and the interior of the socket to permit engagement and disengagement therebetween only by the application of predetermined forces. The holding means may comprise deformable parts on the shank.The re-entrant recess may be a re-entrant slot in which case, after engagement of the head therein the latter may be moved longitudinally of the slot and retained in a desired position by the spring means.

Another aspect of the invention provides a rectangular secondary glazing panel in combination with a plurality of removable fasteners according to the preceding paragraph; the panel comprising extruded frame members each having an open slot to receive a glazing unit and a re-entrant slot opening on the same side of the panel to receive the heads of plugs of the fasteners, the sockets being for disposition in a primary window frame. Each frame member may also have an additional configuration for receiving a sealing element such as a nylon brush for engagement with the primary window frame.

A fastener and a method of using it according to an embodiment of the invention will be described by way of example with reference to the accompanying drawings in which: Figures 1 and 2 are perpendicular views of a plug forming part of a fastener, Figure 3 is a perspective view of part of a secondary glazing frame having the plug of Figs. 1 and 2 mounted therein, Figure 4 is a cross-section of the frame and plug of Fig. 3, Figure 5 shows a socket for use with the plug of Figs. 1 and 2, Figure 6 is a section showing the plug of Fig. 5 mounted in a primary window frame, Figure 7 is a section showing a secondary glazing panel mounted on a primary window frame.

The plug shown in Figs. 1 and 2 comprises a cylindrical shank 1 having a pointed end 2 and a head 3 comprising a pair of outwardly sprung tangs 4. The plug also comprises a spring leaf 5 between the head and shank and a plurality of ciruclar ribs 6 projecting outwardly from the shank 1. The plug is an integral member of plastics material.

The plug is dimensioned so that the head may be inserted in the re-entrant recess of a longitudinal frame section 7 as shown in Figs.

3 and 4. The recess has a pair of inturned lips 8 between which the head may be inserted, the tangs 4 being pressed inwardly by the lips. After insertion the tangs spring outwardly to engage the lips as shown in Fig. 4 to retain the head in the recess. Spring 5 then bears on the outer surfaces of lips 8 to hold the plug in its position along the frame section by friction. The shank 1 extends perpendicularly to the frame section.

The plug is associated with the socket shown in Fig. 5. The socket comprises a cylindrical member 9 closed at one end and having an outwardly extending flange 10 at its open end. Member 9 has outwardly projecting barbs distributed on its surface. The socket is made of plastics material and has an internal diameter such that shank 1 may be inserted with ribs 6 engaging the inner surface of the socket. The shank is then retained in the socket by friction and an appreciable force has to be exerted to remove it.

The frame section 7 is an extrusion of aluminium alloy and forms part of a rectangular frame of a secondary glazing panel. The frame comprises four longitudinal sections of the type shown in Fig. 3 which are joined together at the corners of the panel in known manner. The sections have an inwardly directed slot 12 to accommodate the edge of glass sheet 13, which is held in place by deformable seal 14 in the slot. When the panel is mounted in place on a support member which is generally a primary frame surrounding an existing window, a hole may be drilled in the support member 15 (Fig. 6) and the socket inserted in the hole, which is of diameter such that barbs 11 retain the socket in the hole. Shank 1 of the plug mounted in the frame section as shown in Fig. 3 is then inserted in the socket and held therein by ribs 6.Any desired number of plugs may be inserted in the recesses of the frame sections, distributed around the frame of the panel, and engaged in corresponding sockets in the support member to hold the panel in place.

The frame member has a further slot to accommodate a nylon brush 21 forming a sealing element extending around the periphery of the glazing panel inside frame sections 7.

A preferred procedure for mounting the panel on an existing wooden window frame is to first insert the plugs in the re-entrant recess, as shown in Figs. 4 and 5, at the desired locations around the secondary frame.

The spring leaves 5 hold the plugs in their fitted positions unless a positive force is applied to the plugs to move them along the frame section. The panel is then held in its desired position against the wooden frame and pressure is applied to it to push the pointed ends 2 of the shanks against the wooden frame. The pointed ends penetrate the wood to some extent and thus mark the exact locations of the plugs on the frame. The panel is then removed and the wooden frame is drilled at the locations of the marks. The sockets are then inserted in the drilled holes and the panel is easily fixed in place with the shanks entering the sockets.Using this method of mounting the required positions of the sockets are exactly defined by the plugs which are held in place by the springs 5 throughout the operation, and no measurements are necessary to determine the required positions of the sockets.

The arrangement described above allows a secondary glazing panel to be mounted securely in place. However it may be removed, for example for cleaning, without damage to the panel or primary frame simply by pulling the plug shanks out of the sockets.

Several different types of secondary glazing panel may be held in place in this manner, including those known as fixed panels, lift-out panels and hinged lift-out panels.

The panel may also be of the hinged type, in which case one of the frame sections will be mounted on hinges secured to the primary frame and the frame section on the opposite side of the panel may be held to the primary frame by one or more plugs and sockets of the kind described above, generally in the vicinity of a handle attached to the panel for opening and closing it. The plug and socket may thus be used as a catch. A stay-bar for a hinged panel may also be mounted in place using the plug and socket.

The glazing panel and fastener described above are cheap to manufacture and easy to install. After installation the glazing frame does not have any outwardly visible fixing attachments, on the other hand when the panel is removed from its primary frame the sockets remaining have a neat appearance and are not obtrusive.

Claims (10)

CLAIMS 1. A removable fastener comprising a socket to be disposed within a blind hole in a base and a plug having a shank to extend within the socket and a head for engagement with a member to be held against the base; the head having a deformable part enabling it to be inserted by movement in one direction in a re-entrant recess in the member but precluding removal therefrom by movement in the opposite direction; spring means between the shank and the head for engagement with the member externally of the recess to hold the head firmly within the latter and holding means engageable between the shank and the interior of the socket to permit engagement and disengagement therebetween only by the application of predetermined forces. 2. A rectangular secondary glazing panel in combination with a plurality of removable fasteners according to Claim 1, the panel comprising extruded frame members each having an open slot to receive a glazing unit and a re-entrant slot opening on the same side of the panel to receive the heads of plugs of the fasteners, the sockets being for disposition in a primary window frame. CLAIMS

1. A removable fastener comprising a socket to be disposed within a blind hole in a base and a plug having a shank to extend within the socket and a head for engagement with a member to be held against the base; the head having a deformable part enabling it to be inserted by movement in one direction in a re-entrant recess in the member but precluding removal therefrom by movement in the opposite direction; spring means between the shank and the head for engagement with the member externally of the recess to hold the head firmly within the latter and holding means engageable between the shank and the interior of the socket to permit engagement and disengagement therebetween only by the application of predetermined forces, the shank having a pointed end remote from the head for marking the location of the base at which the blind hole is to be provided.

2. A fastener according to claim 1, in which the holding means comprise deformable parts of the shank.

3. A fastener according to claim 1 or 2, in which the deformable part of the head comprises a pair of outwardly sprung tangs.

4. A removable fastener, substantially as hereinbefore described with reference to the drawings.

5. A secondary glazing panel in combination with a plurality of removable fasteners according to any preceding claim, the panel comprising extruded frame members each having an open slot to receive a glazing unit and a re-entrant slot to receive the heads of the plugs of the fasteners, the sockets being for disposition in a primary window frame.

6. A panel according to claim 5, provided with a sealing element on the same side of the frame members as the re-entrant slot to provide a seal between the panel and the primary frame.

7. A panel according to claim 6, in which the sealing element comprises a nylon brush.

8. A secondary glazing panel, substantially as hereinbefore described with reference to the drawings.

9. A method of installing a secondary glazing panel according to any one of claims 5 to 8 on a primary window frame, which comprises inserting the heads of the plugs of the fasteners in the re-entrant slot at spaced positions along the frame members, pressing the panel against the primary frame so that the points of the fasteners mark the primary frame, drilling holes in the primary frame at the positions marked by the points, inserting sockets in the holes and applying the panel to the primary frame so that the shanks enter the sockets.

10. A method of installing a secondary glazing panel, substantially as hereinbefore described with reference to the accompanying drawings.