1. Field of the Invention
This invention relates to a window wherein a panel is mounted in a window frame in such a manner as to cover the outer surfaces of mullions or vertical frame members which are components of the window frame.
2. Description of the Prior Art
There is so far known a window comprising a rectangular window frame formed by a pair of upper and lower horizontal frame members, and a pair of left and right vertical frame members assembled therewith, and a panel whose upper and lower margins are fitted in and supported by the downward recess of the upper horizontal frame member and the upward recess of the lower horizontal frame member, the arrangement being made such that the pair of left and right vertical frame members are covered with the panel by adhesively bonding the inner left and right vertical margins of the panel onto the outer surfaces of the pair of left and right vertical frame members, respectively.
Further, as described in Japanese Laid-Open Specification No. SHO 63-268849 of Japanese Patent Application, there is also known a window which comprises a window frame including at least a pair of mutually adjacent left and right mullions having engaging flanges formed integrally therewith, and a panel whose left and right vertical margins are adhesively bonded to two vertical frames having U-shaped and inverted U-shaped sections, respectively, so as to form openings adapted to be engaged with these left and right engaging flanges, the panel being mounted on the outer surfaces of the left and right mullions so as to cover the latter.
The former prior art window is pleasing in appearance since the pair of left and right vertical frame members cannot be seen from the outdoor side; however, in case of damage of the panel, etc., replacement of the panel is difficult since the outer left and right margins of the panel are adhesively bonded to the outer surfaces of the pair of left and right vertical frame members, respectively.
The latter window disclosed in the above-mentioned Japanese Laid-Open Patent Application has the following disadvantages.
(1) In case the panel is mounted:
The above-mentioned vertical frames are adhesively bonded to the left and right vertical margins, respectively, of the panel. Subsequently, the panel in such a condition is located diagonally relative to the panel mounting surface, and the flange on one side thereof is engaged with or fitted in the opening in the vertical frame on one side thereof. Then, the panel is turned in a horizontal plane about the engaging portion on one side thereof which serves as a fulcrum (or center) so as to locate the surface of the panel flush with the panel mounting surface. After that, the panel is moved towards the engaging flange on the other side thereof and in parallel thereto so as to engage the latter with the opening of the vertical frame bonded to the other margin of the panel.
Thus, the heavy panel must be moved obliquely in one direction, or moved in parallel, or to another direction so that the panel mounting work becomes very troublesome. Further, once the engaging flange on one side thereof has been engaged with the opening of the vertical frame on one side thereof, the panel is moved in parallel so as to allow the engaging flange on the other side thereof to engage with the opening of the vertical frame on the other side thereof, and as a result, the length of engagement of the vertical frames bonded to the left and right vertical margins of the panel with the left and right engaging flanges becomes short thereby weakening the strength of the panel mounted portions.
(2) In case the panel is dismounted:
The operations mentioned in the above item (1) are conducted in reverse order, and therefore the panel removal work is very troublesome.