Apparatus for making heat-insulated structural section assemblies

The invention relates to apparatus for making a heat-insulated structural section assembly for use in window and door frames consisting of at least two structural metal sections transversely connected to each other by at least one heat-insulating bar and including at least one pressure roller which is adapted to apply pressure against a flange on the structural section in order to hold the heat-insulating bar firmly in place. The improvement resides in the provision of oblique, parallel grooves in the peripheral surfaces of said pressure roller, oriented at an acute angle to the direction of rotation of the pressure roller.

CROSS-REFERENCES TO RELATED APPLICATIONS 
In my co-pending prior application Ser. No. 967,536 filed Dec. 7, 1978, I 
disclose a method and apparatus for making a heat-insulated structural 
section assembly for use in window and door frames consisting of two 
structural metal sections transversely connected to each other by a pair 
of parallel, plastic heat-insulating bars spaced from each other and 
having longitudinal ends of swallow-tail cross-sectional shape which are 
successively received between pairs of longitudinally extending opposite 
grooves each defined by upper and lower flanges in said structural 
sections. This pair of heat-insulating bars defines an enclosed space, and 
said grooves loosely receiving first one of said heat-insulating bars are 
closed upon said one heat-insulating bar by continuously pressing said 
upper flanges of the respective grooves against said one heat-insulating 
bar. 
In this prior application, I disclose a pair of pressure rollers which are 
vertically adjustable to apply pressure against the flanges in the 
structural sections in order to hold the heat-insulating bars firmly in 
place. 
BACKGROUND OF THE INVENTION 
In the apparatus as disclosed in my said prior application, the pressure 
rollers have smooth rims and it is possible for the pressure rollers to 
slide off the flanges so that a defective joint is produced between the 
heat-insulating bars and the structural metal sections. 
It is the object of the invention to improve my prior apparatus in such a 
manner that the pressure rollers steadily and without fail bear against 
the flanges throughout the formation of the structural section assembly. 
BRIEF SUMMARY OF THE INVENTION 
According to the invention, I provide in apparatus for making a 
heat-insulated structural section assembly for use in window and door 
frames consisting of at least two structural metal sections transversely 
connected to each other by at least one heat-insulated bar and including 
at least one pressure roller which is adapted to apply pressure against a 
flange on the structural section in order to hold the heat-insulating bar 
firmly in place, wherein the improvement resides in the provision of 
oblique, parallel grooves in the peripheral surfaces of said pressure 
roller, oriented at an acute angle to the direction of rotation of the 
pressure roller. 
The grooves or indentations in the periphery of the pressure roller or 
rollers are oriented at an angle between 20.degree. and 60.degree. to the 
direction of travel of the metal sections, but an angle of 45.degree. is 
preferred. The invention is not limited to the use of two parallel 
heat-insulating bars, but the provision of the oblique peripheral grooves 
in the roller(s) works equally well with a single heat-insulating bar. 
The effectiveness of the grooved pressure roller(s) is independent of the 
width of the roller, but rather depends on the degree with which the 
grooved pressure roller bites into the flange or flanges on the metal 
sections. Instead of grooves (which are indented), the pressure roller(s) 
could be provided with raised lands which would bite equally well into the 
flanges of the metal sections, which are usually made of aluminum or other 
light metal. The term "groove" when used herein thus includes raised 
lands. 
Irrespective of the diameter of the pressure roller or rollers, the 
distance between the grooves should be between 2 and 6 mm as if greater 
the effectiveness is reduced. The grooves or indentations or raised lands 
have preferably a rectangular cross-section as the sharp corners of the 
cross-section will enhance the biting action of the pressure roller or 
rollers. 
The depth and width of the grooves is between 0.5 and 1.5 mm. The grooves 
are easily formed by cutting or milling into the peripheries of the 
rollers. 
The invention will now be described in greater detail with reference to the 
accompanying drawings showing a preferred embodiment thereof.

DETAILED DESCRIPTION 
Referring to FIG. 1 of the drawings, it will be seen that the apparatus of 
the invention for making the heat-insulated structural sections consists 
essentially of two vertically adjustable pressure rollers 14 and 15, which 
are arranged one behind the other in the direction of travel of the 
section (indicated by arrow 21). In the arrangement show in FIG. 1, a 
first lower insulating bar 1 has been securely inserted between grooves 2 
and 3 of metal sections 4 and 5. Flanges 6 and 7 which define the upper 
walls of grooves 2 and 3 have already been bent down and are firmly 
pressed against the lower heat-insulating bar 1 by the action of pressure 
rollers. 
A second, upper heat-insulating bar 9 has also been pulled into place 
between opposing grooves or cavities 10 and 11 of metal sections 4 and 5. 
The arrangements shown in FIG. 1 illustrates the manner in which upper 
flanges 12 and 13 are forced against the upper side of the upper 
heat-insulating bar 9 by pressure rollers 14 and 15. The direction of 
rotation of the pressure rollers 14, 15 as indicated by arrows on each 
pressure roller is anti-clockwise in the view of FIG. 1 and the direction 
in which the formed section assembly is advanced is indicated by arrow 21. 
(The feed rollers are omitted from this view for the sake of clarity.) 
In order to ensure that the flanges 12, 13 are forced down against the 
upper heat-insulating bar 9 without faulty, spots the peripheral surfaces 
14' and 15' of the pressure rollers 14 and 15 are formed with oblique, 
parallel grooves or indentations 30 which are oriented at an angle to the 
axis of the rollers. 
The distance A, between adjacent grooves, the width B, and depth T of the 
individual grooves are illustrated clearly in FIG. 3. 
As shown clearly in FIG. 2, seen in the direction of rotation of the 
pressure rollers 14, 15, the longitudinal axes 31 of the grooves 30 form 
acute angles alpha .alpha. with the straight line 32 tangential to and 
pointing in the direction of rotation of the pressure rollers 14 and 15. 
The tangent 32 and angle .alpha. are also shown in FIG. 1. This angle 
.alpha. on one of the pressure rollers thus opens towards the other 
pressure roller, which is towards the same side as the grooves 2, 10 or 3, 
11 of the profiled section 4 or 5 which are contacted by the pressure 
rollers 14 and 15 respectively. The grooves 30 are thus directed towards 
each other in a V-shaped formation against the feed direction 21 of the 
metal sections. 
In the embodiment shown, the grooves 30 are rectangular in section (as seen 
in FIG. 3) and when forced against flanges 6, 7 or 12, 13 form 
correspondingly shaped raised areas 33, the depth (or height) of which 
naturally depends on the pressure applied by roller 14, 15. The raised 
area 33 in the feed direction 21 of the metal sections point toward each 
other in V-formation or herring-bone fashion. 
The provision of grooves 30 ensures that the pressure rollers are firmly 
and securely held with their peripheral surfaces against flanges 6, 7 or 
12, 13 and the rollers are prevented from sliding off the flange surfaces. 
FIG. 4 shows a vertical section through the pressure rollers 14, 15, the 
structural sections and adjacent guide and feed rollers. 
As shown, the pressure roller 14, 15 are slightly inclined to the vertical. 
The metal sections 4, 5 are guided laterally between guide rollers 34, 
indicated in outline. 
In the preferred embodiment, the pressure rollers 14, 15 are made from tool 
steel with a diameter of about 100 mm and a thickness of a few 
millimeters. The steel feed rollers 24 which are located below the metal 
sections and again shown in outline, only have a diameter of about 200 mm. 
The guide rollers 34 located on either side of metal sections 4, 5 are 
made from plastic and have a diameter of about 100 mm. 
Depending on the thickness of the light alloy metal sections 4 and 5, the 
thickness of rollers 24 varies between 50 and 150 mm and the thickness of 
guide rollers 34 between 30 and 60 mm. 
The rectangular groove 30 in the periphery of the pressure rollers 14, 15 
are inclined at an angle .alpha. of 20.degree. to 60.degree. and have a 
depth T and a width B between 0.5 and 1.5 mm, preferably about 1 mm. The 
distance A between adjacent grooves is between 2 and 6 mm, preferably 
about 4 mm.