Method of assembling window and glass-door casements

A method of assembling window and glass-door casements, such as casements of the kind which comprise four aluminium profiled sections, made from aluminium assembled to form a rectangular frame, each section is shaped with a U-shaped channel along the profiled section, the four profiled sections being joined together at each of the four corners where the sections meet, the ends of the profiled sections being cut obliquely so as to form mitered corners where they join, and wherein one or more glass panes are later fitted to the frame;

• the method comprising:
• providing for each of the profiled sections within the bottom of the U-shaped channel with a slot of essentially flat rectangular cross-section which is essentially closed in cross-section;
• providing for each corner of the casement frame a flat right-angled fastener device having two legs whose cross-sectional shape corresponds generally to the cross-sectional shape of said slot;
• shaping the inner edges of each leg of each fastener device with at least one notch;
• inserting the legs of said fastener device individually into a slot of respective adjacent profiled sections;
• moving said adjacent profiled sections into abutment with one another over the inserted fastener legs to form a preassembled rectangular casement frame;
• fitting each of the four corners of the preassembled frame into a press tool means having at least one tool which include a fixed part having two abutment sides which form a right angle with one another, and a movable part having a second set of two abutment sides which form essentially a right angle with one another;
• further steps of said method comprising:
• making, on said second set of two abutment sides, projections which correspond to said notches;
• said second set of right angled abutment sides being parallel with the first-mentioned set of two abutment sides;
• the movable part of a tool being constructed so that it is movable towards and away from the associated fixed part of the tool in response to a relative force applied between said fixed and movable parts;
• when fitting said casement frame in said press tool means, placing a corner of the preassembled casement frame between spaced apart fixed and movable parts of a respective associated tool;
• forcing the movable part of said associated tool towards the fixed part of said tool in a direction which extends at an angle of 45 to the longitudinal axes of the associated two corner-forming profiled sections, with the inner walls of the two associated corner forming profiled sections located between the inner edges of the legs of the inserted fastener device and the second set of angled abutment sides of the movable part of the associated tool;
• and forcing the projections on the sides of the movable part of the associated tool to engage and deform said inner walls at the inside of the corners of the preassembled profiled section to an extent such that said wall will essentially be deformed and brought into conformity and locked with the notches in the edges of the legs of the associated fastener device.