Patent Publication Number: US-2016237735-A1

Title: Foam Filled Frame Member

Description:
This invention relates to a frame member, for example for use in the formation of window or door frames, the frame member defining a foam filled cavity. In particular, the invention relates to a frame member including at least one extruded metallic frame component, for example of extruded aluminium form. 
     Aluminium and other metallic materials have been used, for many years, in the manufacture of window and door frames. One disadvantage with the use of such materials is that they are of good thermal conductivity. Consequently, heat loss from a building including window or door frames of metallic form can be unacceptably high, and condensation tends to form on the window or door frames. In order to reduce these problems, it is known to manufacture frame members in such a manner as to include an inner frame component rigidly secured to, but spaced apart from, an outer frame component, the manner in which the frame components are interconnected being such as to provide a thermal break of good thermal insulting properties therebetween. 
     One known technique involves manufacturing the inner and outer frame components as a single unit that is shaped to define a channel, pouring a resin material into the channel and, once the resin has cured, machining away the metallic material originally interconnecting the inner and outer frame components to leave a frame member made of inner and outer frame components rigidly interconnected only by the resin material which provides the required thermal break between the inner and outer components. 
     Another known technique involves interconnecting the inner and outer frame components using components with relatively low thermal conductivity to define a void, and introducing a foaming material into the void to substantially fill the void. 
     In order to enhance the levels of thermal insulation that can be attained it is desirable to increase the distance by which the inner and outer frame components are spaced apart. Clearly, if the strength of the frame member is to be maintained, this can result in the arrangement by which the frame components are interconnected and by which the thermal break is provided being required to bear additional loadings. 
     It is an object of the invention to provide a frame member whereby the spacing of the frame components thereof can be increased. 
     According to the present invention there is provided a frame member comprising first and second frame components spaced apart from one another and connected to one another by a first bridge and by a second bridge, the first and second frame components and first and second bridges together defining an elongate void, a foam material located within the void and substantially filling the void, and a tie member interconnecting the first and second bridges to restrain the first and second bridges against movement towards or away from one another. 
     The tie member is conveniently provided with a series of openings through which the foam material extends such that the foam material extends continuously between the first and second frame components. 
     The first bridge conveniently comprises a plastics material component, conveniently of extruded form. The second bridge similarly conveniently comprises a plastics material component. Alternatively, the second bridge may take the form of one or more cured resin elements, cured in situ, providing a connection between the first and second frame components. 
     The first frame component may be of hollow form, and the foam material may extend continuously into the hollow of the first frame component. 
     The invention further relates to a method of manufacture of such a frame member. 
    
    
     
       The invention will further be described, by way of example, with reference to the accompanying drawings, in which: 
         FIG. 1  is a view illustrating a frame member in accordance with one embodiment of the invention; 
         FIGS. 2 and 3  are views illustrating part of the frame member of  FIG. 1 ; 
         FIGS. 4 a  and 4 b    illustrate stages in the process by which the frame member of  FIG. 1  is manufactured; and 
         FIGS. 5 a  to 5 f    illustrate stages in the manufacturing process by which the frame member of a second embodiment of the invention may be manufactured. 
     
    
    
     Referring firstly to  FIG. 1 , an insulated frame member  10  for use in the manufacture of, for example, a window or door frame is illustrated. The frame member  10  comprises an inner frame component  12  of extruded aluminium form, and an outer frame component  14  also of extruded aluminium form. The inner and outer frame components  12 ,  14  each include first and second connection features  16 ,  18 , in the form of generally L-shaped projections, whereby first and second bridges  20 ,  22  of extruded plastics material form are secured to the inner and outer frame components  12 ,  14 . As illustrated, each of the bridges  20 ,  22  is provided, at the opposite edges thereof, with a generally L-shaped recess  24  adapted to receive respective ones of the connection features  16 ,  18 . 
     It will be appreciated that with the inner and outer frame components  12 ,  14  interconnected by the first and second bridges  20 ,  22 , an elongate void is formed therebetween which, as illustrated, is filled with a foamed material  26 . 
     As shown in  FIG. 1 , adjacent its midpoint each of the bridges  20 ,  22  is provided with a re-entrant recess  28 , the recesses  28  being aligned with one another and receiving respective end parts of a generally I-shaped tie member  30 . As shown in  FIGS. 2 and 3 , the tie member  30  comprises upper and lower flanges  32  that, in use, are received within the recesses  28 , the flanges  32  being interconnected by a web  34  that is formed with a series of openings  36 . 
     As shown in  FIG. 1 , the outer frame component  14  is provided with a similar pair of aligned recesses  28   a , a similar tie member  30   a  being associated therewith. 
     During assembly or manufacture, as illustrated in  FIGS. 4 a  and 4 b   , the inner and outer frame components  12 ,  14  are interconnected by the first and second bridges  20 ,  22 , this conveniently being achieved by engaging end parts of the features  16 ,  18  in end parts of the recesses  24 , and sliding the bridges  20 ,  22  in the axial direction relative to the frame components  12 ,  14 . The tie members  30 ,  30   a  are similarly fitted in position by axial sliding. Once the frame components  12 ,  14 , bridges  20 ,  22  and tie members  30 ,  30   a  have been assembled as shown in  FIG. 4 b   , a foaming material is introduced into the void  26  defined between the frame components  12 ,  14  and the bridges  20 ,  22 , the foaming material foaming and expanding to fill the void  26 . It will be appreciate that during foaming the material  26  is able to pass through the openings  36  provided in the tie members  30 ,  30   a . Accordingly, in the finished product as shown in  FIG. 1  the foam material  26  extends continuously from the inner frame component  12  to the outer frame component  14 . Furthermore, in this embodiment, the foam material extends continuously through the tie member  30   a  into the outer frame component  14 , filling or substantially filling a void of hollow formed therein. 
     During foaming of the foam material  26 , it will be appreciated that significant loadings are applied to the bridges  20 ,  22  urging them apart. However, the presence of the tie member  30  serves to resist such movement, thereby ensuring that the final product is of the desired shape and that bowing or other deformation of the bridges  20 ,  22  is avoided. Likewise, the presence of the tie  30   a  serves to resist deformation of the outer frame component  14  that could otherwise occur during foaming of the material located therein. 
     It will be appreciated that by providing the tie member  30  between the bridges  20 ,  22 , and thereby resisting bowing or other deformation thereof, the distance by which the inner and outer frame components  12 ,  14  are separated can be increased leading to an enhancement in the thermal insulating properties of the frame member  10  without resulting in deformation of the product. 
     Whilst the description hereinbefore relates to an arrangement in which both of the bridges  20 ,  22  take the form of extruded plastics material components or the like, the invention is not restricted in this regard.  FIGS. 5 a  to 5 f    illustrate an arrangement in which the first bridge  20  is of this form, but in which the second bridge  22  is manufactured using a so-called pour-and-cut method. In this arrangement, as illustrated in  FIG. 5 a   , the inner and outer frame components  12 ,  14  are manufactured integrally with one another, the inner and outer frame components  12 ,  14  being interconnected by an integral bridge part  40 . The bridge part  40 , together with the inner and outer frame components  12 ,  14 , define upper and lower pairs of channels  42 ,  44 . The channels  42 ,  44  are each shaped to include lips or projections arranged, in use, to interact or interlock with a resin material. 
     As shown in  FIG. 5 b   , during the manufacturing process, a curable resin material  46  is poured into the upper pair of channels  42  and is allowed to cure. After curing, the regions  40   a  of the bridge part  40  defining the bases of the channels  42  are machined away, as shown in  FIG. 5 c   . It will be appreciated that at this point, the inner and outer frame components  12 ,  14  are interconnected only by the remaining central region of the bridge part  40  and by the cured resin material  46  in the channels  42 . Subsequently, as shown in  FIG. 5 d   , additional resin material  46  is applied to fill the channels  44 , and this resin material  46  is allowed to cure. 
     Subsequently, a first bridge  20  is slid into position, interconnecting the inner and outer frame components  12 ,  14  in much the same manner as the first bridge  20  of the embodiment shown in  FIGS. 1 to 4 . A tie member  30  of the same general form as that of the embodiment of  FIGS. 1 to 4  is used to interconnect the first bridge  20  and the bridge part  40  forming part of the second bridge  22 . It will be appreciated that in this condition a void is defined between the inner and outer frame components  12 ,  14  and the first and second bridges  20 ,  22 , to which a foaming material is applied such that, once foamed, the void will be substantially filled with foam material  26 . 
     In both of the embodiments described hereinbefore, once foamed, the foam material  26  serves to tightly lock the component parts of the frame member  10  to one another, the tie members  30  serving to restrain at least the first bridge  20  against bowing or deformation. Accordingly, the inner and outer frame components  12 ,  14  can be spaced apart by a relatively great distance. By arranging for at least one of the frame components  12 ,  14  to include a void (as in the embodiment of  FIGS. 1 to 4 ) the foam material  26  can extend continuously into that frame component  12 ,  14 , further enhancing the strength and the thermal insulating properties of the frame member. By using a pour-and-cut method in the formation of one of the bridges, as in the embodiment of  FIG. 5 , the physical strength, as well as the thermal insulating properties, of the frame member can be enhanced. 
     Whilst the description hereinbefore relates to two specific embodiments, it will be appreciated that a wide range of modifications and alterations may be made or incorporated without departing from the scope of the invention as defined by the appended claims.