GB2197015A

GB2197015A - Plastic clad timber frames

Info

Publication number: GB2197015A
Application number: GB08721399A
Authority: GB
Inventors: Bryan Garner Mcdougall
Original assignee: Leaderflush Doors Ltd
Current assignee: Leaderflush Doors Ltd
Priority date: 1986-09-11
Filing date: 1987-09-11
Publication date: 1988-05-11
Anticipated expiration: 2007-09-11
Also published as: GB2197015B; GB8621969D0; GB8721399D0

Abstract

An elongate frame member for use in constructing door or window frames comprises a main wooden body portion (15) and a plastics cover strip (16) insertable laterally onto the main body portion so that cooperating formation (32, 35) resist removal of the cover strip. A projecting tip 41 can seal eg against a wall. <IMAGE>

Description

SPECIFICATION Plastics clad timber frames The present invention relates to plastics clad timber frames in particular, but not exclusively, used in building construction. The invention is particularly suitable for window frames and door frames.

The present invention also relates to a method of cladding timber frames with a plastics material.

In certain environments, such as hospitals, it is desirable to provide frames which have surfaces which can be easily cleaned and preferably require little maintenance. It is therefore desirable to produce frames from conventional materials such as timber and yet cover the exposed surfaces of the frame with a suitable covering material such as a plastics material.

According to one aspect of the present invention there is provided an elongate frame member for use in constructing frames, the frame member including a main body portion, which is preferably formed from timber, and a cover strip which is insertable in a lateral direction onto the main body portion, the main body portion and cover strip including a cooperating formation for resisting removal of the cover strip from the main body portion.

Preferably, the main body portion is generally rectangular in section and the cover strip is arranged to cover three adjacent sides of the body portion.

In one embodiment of the invention the cooperating formations are such that the cover strip is able to be inserted onto the main body portion whilst one surface of the main body portion is in abutment with a support surface.

According to another aspect of the present invention there is provided a door or window frame constructed from frame members as defined above.

Various aspects of the present invention are hereinafter described with reference to the accompanying drawings, in which: Figure 1 is a perspective view showing a corner portion of a door frame according to one aspect of the present invention; Figure 2 is a view taken along line I in Fig.

1; Figure 3 is a view taken along line II in Fig.

1; Figure 4 is a view similar to Fig. 3 of an alternative construction according to the present invention; Figure 5 is a view similar to Fig. 3 of a further alternative construction according to the present invention; Figure 6 is a view similar to Fig. 3 of a further alternative construction according to the present invention; Figure 7 is a view similar to Fig. 3 of a further alternative construction according to the present invention; Figures 8 and 9 are sectional views of extruded strips used in the construction of Fig.

7 prior to insertion; and Figure 10 is view similar to Fig. 3 of a further alternative construction according to the present invention.

Referring initially to Figs. 1 to 3 there is illustrated part of a door frame 10 having a pair of upright portions connected by a top portion to define a door opening. In Fig. 1 the upper part of one upright portion 11 and a part of the top portion 12 are shown.

The frame illustrated in Figs. 1 to 3 is formed from main frame members 14 comprising a main body portion in the form of main body strips 15 preferably of timber clad on 3 sides by a cover strip 16 to form a first set of elongate frame members. The cover strip 16 is preferably an extrusion of a rigid plastics material such as rigid polyvinyl chloride. The frame members 14 forming the top portion is conveniently butt jointed with the frame members 14 forming the upright portions and are secured together by suitableixing means such as long nails. Accordingly, the main door frame is formed wherein its external exposed surfaces are clad with a plastics material.

In order to provide a shoulder against which the door abuts, a second set of elongate frame members are provided. With this second set strips 20, preferably of timber, are attached to the main frame members 14 conveniently by fixing means such as nails which penetrate through the strip 20, cover strip 16 and into the main body strip 15. The strips 20 are then covered with a cover strip 23 preferably of a plastics material such as rigid polyvinyl chloride to thereby provide continuity of cover with the cover strip 16.

In a similar manner, one or both of the side faces of the main frame members 14 may be partially covered by a third set of elongate frame members in the form of architrave strips 24 which serve to cover the joint between the door frame 10 and the surrounding wall structure. The architrave strips 24 comprise a main body strip 25 preferably of timber which is secured to the frame members 14 by fixing means such as nails and then is clad by a cover strip 27 preferably of a plastics material such as rigid polyvinyl chloride.

Accordingly, the outer exposed surfaces of the finished door frame are defined by plastics covers.

The abutting edges of adjacent cover strips 16, 23 and 27 may conveniently be filled or sealed with suitable materials to provide a hermetic joint.

As clearly seen in Figs. 2 and 3, strips 23 include opposed side walls 30 which are connected at one edge by a base wall 31 and which are provided adjacent their opposite terminal edge with an inwardly projecting rib 32.

Each rib 32 defines a shoulder for co-operating with a rebate 35 formed in strip 20 to restrain removal of the cover strip 23 from strip 20.

The cover strip 23 is attached to strip 20 by flexing the side walls 30 outwardly and sliding the cover over the strip 20 until the ribs enter the rebates 35 at which time the walls 30 flex inwardly under their own bias.

Preferably each rib 32 is provided with an inclined face 38 which serves to guide and flex the associated side wall outwardly as the cover strip 23 is initially presented to and pressed onto strip 20. Preferably the outermost corners of strip 20 are radiused to facilitate the action of the inclined faces 38.

The depth of sidewalls 30 is chosen to be substantially the same as the depth of the strip 20 being covered so that when in position on strip 20 the terminal edge of the sidewalls 30 abuts or is closely spaced from the surface to which strip 20 is attached. If desired, one or both sidewalls 30 may be provided with a first projecting lip formation 40 which serves to form a radiused connection between the sidewalls 30 and the surface to which strip 20 is attached. The lip formation 40 is preferably formed integrally with the cover strip 23 and may be formed from a rigid or flexible plastics material such as rigid or flexible polyvinyl chloride.

The strips 25 and associated cover strips 27 are preferably of a similar construction to strips 20 and 23 and have been referenced by similar reference numerals. Cover strip 27 is illustrated as having a projecting lip 41 which depends from the terminal edge of one sidewall 30 and is intended to contact the surrounding wall structure.

The cover strips 16 for the main frame members 14 may include two sidewalls 30 having a rib 32 of similar construction to that described in respect of strip 23 above; however in Figs. 1 to 3 the strip 16 is shown wherein one sidewall 30 has an inwardly directed wall portion 50 which defines an additional secure corner portion. The wall portion 50 is provided at its terminal edge with an inwardly directed rib 51 which is received in a groove 52 formed in the main body strip 15.

The rib 51 co-operates with groove 52 to restrain outward movement of the associated sidewall 30. The main body strip 15 is provided with a recess to accommodate the thickness of the wall portion 50 such that its outer surface 50a is contiguous with the outer face 15a of the main body strip 15.

Accordingly should the side wall 30 having wall portion 50 not be covered in the finished door frame by architrave strip the cover strip 16 will remain securly connected to main body strip 15.

In Figs. 4 and 5 alternative constructions are illustrated adopting main frame members 14 and strips 20 covered by strips 23. Accordingly the same reference numerals are used where appropriate.

In Fig. 4, the arrangement shown in Fig. 2 is illustrated wherein the surrounding wall structure 100 is slightly broader than the frame member 14. In order to accommodate for the difference in width, architrave strips 24 are used to cover both sides of the frame member 14 and the cover strips 27 are provided with second projecting lips 40, preferably of a flexible plastics material, which extend toward and abut onto the sidewalls 30 of strip 16 to thereby cover the gap 60 between the architrave strip 24 and frame member 14.

In Fig. 5 a construction is shown which is appropriate for connecting a sheet material such as cladding to the outer surface 15a of the main body strip 15. A groove 70 for locating the sheet material is defined by a fourth set of elongate frame members in the form of a pair of composite strips 71 of similar construction to covered strips 20. A flat strip 72 formed preferably of a plastics material is interposed between strips 71 and the outer face 15a.

In addition to providing cover for the exposed marginal edges of the frame member 14, the strips 72 help secure sidewalls 30 in position. In this respect, one strip covers wall portion 50 and thereby retains rib 51 in its groove 52; the other strip 72 overlaps the terminal edge of the neighbouring sidewall 30 and is preferably bonded thereto to thereby restrain outward deflection of the sidewall 30.

In Fig. 6, an alternative construction is illustrated wherein the main frame members 14 are divided into two portions 14a, 14b to enable varying widths of wall structure 100 to be accommodated.

Accordingly frame member portions 14a, 14b are each made up to form door frames and connection means such as dowelling 80 is provided to enable the frame member portions 14a, 14b to be connected together after they have been presented to and fitted in an opening in a wall structure 100.

The joint 82 between the frame member portions 14a, 14b is then covered by the door stop strip 20 which itself is then covered by a strip 23.

The frame member portions 14a, 14b are preferably provided with a rebate 84 to thereby define a shoulder 85 which overlaps and abuts against the surrounding wall structure 100.

The cover strip 16a for frame member portions 14a, 14b has a relatively short sidewall 30a and a longer sidewall 30b. Sidewall 30a is provided with a rib 32 and sidewall 30b is provided on its inner face with one or more ribs 86 which are received in grooves 87 formed in the main body strip 15a. The sidewall 30b is prevented from outward deflection by the door stop strip 20 and is prevented from sliding across the face of body strip 15a by co-operation between ribs 86 and asssociated grooves 87.

If desired, the door frame portions formed by the main body strips 15a may be fitted to the wall structure opening prior to strips 16a being applied.

In Fig. 7, there is illustrated a modified structure of the type shown in Fig. 6 and similar parts are designated by the same reference numerals.

In Fig. 7 the frame portions 14a, 14b are not provided with a rebate and are fitted flush with the surrounding wall structure 100. In order to cover the joint between the outer sides of the frame portions 14a and 14b and the surrounding wall structure extruded strips 90 are provided. The extruded strips 90 are preferably extruded from a suitable plastics material such as rigid polyvinyl chloride. The extruded strips 90 (see especially Figs. 8 and 9) have a projecting flange portion 91 having projecting ribs 92 which serve to anchor the flange portion 91 in a groove 93 formed in the frame portions 14a, 14b. The sidewall 30c of strip 16a is retained in groove 93 also by the strip 90. In this respect, the flange portion 91 is provided with a shoulder 95 which overlaps the strip 16a and thereby prevents removal of the sidewall 30c from groove 93.In Fig. 7 two different shapes of strip 90 are illustrated.

In the embodiment illustrated in Fig. 10, an alternative construction to that shown in Fig.

6 is illustrated wherein rebate 84 is formed in a different way. In this respect the cover 16 is provided with a flange portion 150 which forms a continuation of wall 31 and which has an inwardly directed wall portion 151. The flange portion 150 thereby defines a channel with sidewall 30a in which is located an elongate frame member 152 which in the illustrated embodiment is of generally square cross-section. The frame member 152 defines shoulder 85 of the rebate 84. Also illustrated in Fig. 10 is the provision of elongate fillets 160 in the gap 85 to provide support for members 23. Clearly one or more fillets 160 may be provided depending on the width of gap 85. In Fig. 10 a door 170 is illustrated having a combined intumescent fire and smoke seal 172. If desired strips of intumescent material 200 may be incorporated in the frame members for instance as illustrated in the accompanying drawings.

Whilst frame members 14, 14a, 14b have been described above for forming a door frame it will be appreciated that these frame members may be used for producing other structures.

Claims

1. An elongate frame member for use in constructing frames, said frame member comprising a main body portion and a cover strip, wherein the cover strip; is insertable in a lateral direction onto the main body portion, and the cover strip and the main body portion include a cooperating formation for resisting removal of the cover strip from the main body portion.

2. An elongate frame member according to Claim 1 wherein the main body portion is generally rectangular in section and the cover strip is arranged on three adjacent sides of the main body portion.

3. An elongate frame member according to Claim 1 or 2 wherein the cover strip comprises opposed side walls each having first and second opposite edges and a base wall, wherein the side walls are connected to each other at the first edges thereof by the base wall.

4. An elongate frame member according to Claim 3 wherein the cooperating formations are such that the cover strip can be inserted onto the main body portion whilst one surface of the main body portion is in abutment with a support surface.

5. An elongate frame member according to Claim 4 wherein the depth of the side walls is substantially the same as the depth of the main body portion so that when the cover strip is in position on the main body portion the second edge of the side walls abuts or is closely spaced from the support surface.

6. An elongate frame member according to Claim 3, 4 or 5 wherein the cooperating formation comprises detent formations.

7. An elongate frame member according to Claim 6 wherein the detent formations comprise an inwardly projecting rib on the second edge of at least one side wall, and at least one rebate formed in the main body portion, so that the rib can fit within the rebate.

8. An elongate frame member according to Claim 7 so constructed and arranged so that the cover strip is inserted onto the main body portion by causing the or each side wall to flex outwardly and sliding the cover strip over the main body portion until the or each rib reaches the or each rebate at which time the or each side wall flexes inwardly.

9. An elongate frame member according to Claim 8 wherein the or each rib has an inclined face to guide and flex the or each side wall outwardly as the cover strip is inserted onto the main body portion.

10. An elongate frame member according to Claim 8 or 9 wherein the outermost corners of the main body portion are radiused to facilitate the flexing outwardly of the side walls.

11. An elongate frame member according to any of Claims 4 to 10 wherein one of said side walls comprises an inwardly directed wall portion which is provided at its terminal edge with a rib, and wherein said main body portion comprises a groove, whereby said rib can be received within said groove and can cooperate with said groove to restrain outward movement of the side wall.

12. An elongate frame member according to any of Claims 4 to 11 wherein the cover strip has a first projecting lip depending from the second edge of at least one side wall, said lip being adapted to contact the support.

13. An elongate frame member according to any of Claims 4 to 12 wherein the abutting edge of the cover strip and the support are filled or sealed with suitable materials to provide a hermetic joint.

14. An elongate frame member according to any preceding claim wherein the main body portion is formed from timber and the cover strips are formed from a plastics material.

15. A frame for a door or a window constructed from a plurality of elongate members as claimed in any of Claims 1 to 14.

16. A frame according to Claim 15 wherein said plurality of elongate frame members comprises first and second sets of said elongate members; each set comprising a pair of upright elongate frame members and at least one transverse elongate frame member to connect the upright elongate frame members together; said first set being adapted to be fitted into an opening in a wall structure, and said second set forming a shoulder against which a door or a window can abut.

17. A frame according to Claim 16 which further comprises a third set of said elongate members, said third set comprising a pair of upright elongate frame members and a transverse elongate frame member to connect the upright frame members together; said third set forming an artchitrave to cover the joint between the wall structure and said first set.

18. A frame according to Claim 17 wherein when the wall structure is broader than the first set of elongate frame members, the third set can be provided at either side of the wall structure.

19. A frame according to Claim 18 wherein a second projecting lip is provided on the third set and extends between the third set and the first set.

20. A frame according to Claim 16 wherein when the wall structure is broader than the first set of elongate frame members, each frame member of the first set is divided into two portions with a gap between each portion, and connecting means is provided to connect the two portions together.

21. A frame according to Claim 20 wherein each portion is provided with a rebate to define a shoulder which overlaps and abuts against the wall structure at the side thereof.

22. A frame according to Claims 20 or 21 wherein the second set of elongate frame members covers the gap between the two portions of the elongate frame members of the first set.

23. A frame member according to any of Claims 20 to 22 wherein the connecting means comprises a dowelling.

24. A frame according to any of Claims 20 to 23 wherein ribs are provided on the base wall of the cover strips of the first set, said st h bssihfi a 4wed 48 Be i3888iv80 iflPPB- sponding grooves in the main body portions of the first set of frame members.

25. A frame according to Claim 20 wherein the cover strip of each frame member of the first set is provided with a flange portion which has an inwardly directed wall portion to define a channel in which a further main body portion is located.

26. A frame according to Claim 25 wherein the further main body portion defines a shoulder which abuts against the side of the wall structure.

27. A frame according to Claim 25 or 26 wherein elongate fillets are provided in the gap between the formations.

28. A frame according to Claim 20 wherein the first set of frame members are adapted to fit flush with the wall structure and strips are provided on the cover strips of the first set of frame members to cover the joint between the frame members and the wall structure.

29. A frame according to Claim 28 wherein the strips comprise a projecting flange portion having projecting ribs to anchor the flange portion in a groove formed in the main body portion.

30. A frame according to Claim 15 wherein said plurality of elongate frame members comprises first, second and fourth sets of said elongate frame members; each set comprising a pair of upright elongate frame members and at least one transverse elongate frame member connecting the upright elongate members together, said second set being attached to an edge of the main body portion of the first set which is covered by the cover strip, and the fourth set being attached to an edge opposite to said covered edge.

31. A frame according to Claim 30 which comprises two of said fourth sets to enable a sheet material to be connected to the frame.

32. A frame according to Claim 1 wherein a flat strip is interposed between the fourth sets of frame members and the edge to which they are attached, said strips assisting in retaining the cover strip on the main body portion of the first set.

33. An elongate frame member substantially as herein described with reference to and as shown in the accompanying drawings.

34. A frame for a door or a window substantially as herein described with reference to and as shown in the accompanying drawings.