1. Field of the Invention
The present invention relates to a window frame, and more particularly, to a window frame, which is configured so that an assembling process can be performed simply and smoothly, and which has novel corner angles allowing conduction of external heat to be minimized and torsional deformation to be prevented.
2. Description of the Related Art
Generally, a window frame is to separate a dwelling space and an un-dwelling space from each other, and various kinds of windows having a door glass installed thereto are slidably installed to the window frame.
Such a window frame includes a sill frame defining a lower end and installed along the ground, and jamb frames defining an upper end and both side ends.
The sill frame and the jamb frames have concavo-convex inner and outer wall surfaces, and are manufactured by a drawing or extruding process.
However, the sill and jamb frames of the conventional window frame are separately manufactured and then assembled by welding the connected surfaces thereof or coupling them through screws or other coupling members. Thus, there is a problem in that the assembling process is difficult.
That is, during the assembling process of the sill and jamb frames, the connected surfaces thereof should be maintained in an accurately matched state. However, it is very difficult for a sole worker to grip and weld or screw the sill and jamb frames.
In particular, when the sill and jamb frames are directly joined to each other, there is a problem in that the joining region thereof is frequently widened or separated with ease.
There are many efforts to prevent the joining region of the sill and jamb frames from being widened or separated by coupling an additional reinforcement, such as a bracket, to each corner of the window frame.
However, the bracket is formed by bending a general metal thin plate, so that it does not have high torsional or bending strength. Thus, there is a problem in that the bracket is easily bent by external force and thus cannot reinforce the joining regions sufficiently.
In particular, the bracket is configured so that both ends thereof are inserted into the sill frame and one of the jamb frames (or two of the jamb frames), so that it should have a very small thickness, which results in very weak strength.
Further, since the conventional reinforcement is made of metal, its entire weight is heavy.
In the meantime, there has been proposed a structure in which the conventional reinforcement itself forms each corner of a window frame in itself and simultaneously couples the sill frame and the jamb frame to each other. However, since such a structure conducts external heat directly to the indoor space, there is a problem in that a heat protection effect is deteriorated.