before describing the present invention , it is to be noted that like parts are designated by like reference numerals throughout the accompanying drawings . referring first to fig2 and 3 , a window stay embodying the present invention is a unitary structure comprising a panel member , for example , a glass plate 4 , having its peripheral edge portion supported against a window frame 10 by means of a glass retainer 12 connected to the window frame 10 . this unitary window structure is mounted to a wall structure partially shown by 16 in fig . 3 which has a window defining opening 17 provided therein in a manner which will become clear from the subsequent description . the glass plate 4 is generally rectangular in shape and , hence window frame 10 , glass retainer 12 and window defining opening 17 in wall structure 16 are correspondingly rectangular , but the invention is not limited to this shape . as best shown in fig3 the window frame 10 generally comprises a web 10b of predetermined width greater than the thickness of the glass plate 4 used , an abutment flange 10a integral with and extending in one direction from one side edge of the web 10b generally at right angles thereto so as to lie parallel to glass plate 4 , and a mounting flange 10c integral with and extending in the opposite direction from the opposite side edge of the web 10b which has a shape similar to the mathematical square root symbol . adjacent to the joint between the opposite side edge of the web 10b and the mounting flange 10c , the window frame 10 is integrally formed with a rim 13a protruding a slight distance from window frame 10 in the same direction in which the abutment flange 10a extends so as to define a generally right - angled bank 13 between it and the web 10b . on the other hand , the glass retainer 12 is of generally l - shaped cross - section and comprises a clamping flange 12x and a flank 12y which are disposed to lie generally parallel to the abutment flange 10a and the web 10b of the window frame 10 when the glass retainer 12 is coupled to the window frame 10 to make up the unitary window structure in a manner to be described later . the window stay according to the present invention makes use of a generally l - sectioned elastic cushioning strip 11 preferably made of rubber material in the form of a substantially endless loop with a circumference corresponding to the circumference of the glass plate 4 . to make up the unitary window structure , the inside surface of the abutment flange 10a of the window frame 10 , which engages one peripheral surface area 4a of the glass plate 4 , is covered , or otherwise bonded , to an elastic adhesive strip 14 having a cushioning property . after the adhesive strip 14 has been applied to the abutment flange 10a in the manner described above , the glass plate 4 is mounted in the window frame 10 with its peripheral surface area 4a kept in contact with the elastic adhesive strip 14 . the elastic cushioning strip 11 is then mounted circumferentially around the glass plate 4 to permit it to contact and cover both the opposite peripheral surface area 4b of the glass plate 4 and the peripheral cut face 4c of the glass plate 4 . preferably , the elastic cushioning strip 11 is undersized so that when it is mounted circumferentially of the glass plate 4 in the manner as previously described , it can be slightly elongated and , hence , precompressed to avoid its separation from the glass plate 4 during the mounting procedure . thereafter , the glass retainer 12 is fitted in the window frame 10 with its clamping flange 12x and flank 12y held in abutment with the elastic cushioning strip 11 and the web 10b , respectively . as the final step of the mounting procedure , a number of fastening bolts 15 are passed through the flank 12y and then through the web 10b and are fixed in position by associated nuts 15a positioned on one side of the web 10b opposite the glass retainer 12 , thereby completing the unitary window structure . the unitary window structure fabricated as described above is then mounted in the window defining opening 17 in the wall structure 16 with the mounting flange 10c firmly connected to the wall structure 16 by means of set screws or bolts 18 threaded through the mounting flange 10c into the wall structure 16 . alternatively , it may be possible to make up the unitary window structure by first securing the window frame 10 to the wall structure 16 , then mounting the glass plate 4 in the window frame 10 , and finally setting the glass retainer 12 in the manner described above . it is to be noted that , when the glass retainer 12 is set in position on the window frame 10 as best shown in fig3 both the elastic adhesive strip 14 and the elastic cushioning strip 11 are inwardly compressed to provide fluid tightness . this inward compression produces a reactive force as in the case of the elastic cushioning strip employed in the prior art window stay . this reactive force acts , in the instance of the present invention , on the glass retainer 12 to displace the latter in a direction away from the abutment flange 10a of the window frame 10 . however , because of the provision of the rim 13a defining the right - angled bank 13 in which the free side edge of the flank 12y is seated , no actual displacement of the glass retaining member 12 takes place . the elastic adhesive strip 14 applied to the abutment flange 10a of the window frame 10 is preferably made of a fabric strip having its opposite surfaces coated with rubber adhesive material . by way of example , a commercially available double - sided adhesive tape comprising a fabric substrate , such as manufactured and sold by nitto denko k . k . of japan under the trade name &# 34 ; nitto double - sided adhesive tape # 525 &# 34 ;, may be employed as the elastic adhesive strip 14 for the purpose of the present invention . in practice , it is preferred to use two overlapping layers of the double - sided adhesive tape for the elastic adhesive strip 14 . in any event , it has been found that the above - mentioned commercially available double - sided adhesive tape is most suited from the stand points of cushioning effect and bonding power . the glass retainer 12 shown in fig2 and 3 is made up of two split sections 12a and 12b of identical construction each being generally u - shaped in configuration . in other words , the glass retainer 12 employed in the embodiment shown in fig2 and 3 is of two - piece construction . however , it may be of one - piece construction , i . e ., it may be employed in the form of a continuous rectangular glass retaining member as shown in fig9 . where it is desired to employ a continuous glass retainer 12 as shown in fig9 it is preferably slightly oversized so that , when secured firmly to the window frame 10 by means of the bolts and nuts 15 and 15a in the manner described above in connection with the embodiment of fig2 and 3 , both the elastic adhesive strip 14 and the elastic cushioning strip 11 can be inwardly compressed to accommodate the difference in dimension between the slightly oversized glass retainer 12 and the circumference of rim 13a in the window frame 10 . in fig9 the slightly oversized glass retainer 12 is somewhat exaggerated as shown by the chain lines . in any event , the glass retainer 12 according to the embodiment of fig9 has the advantage that it can be set by a simple fitting procedure compared with that according to the embodiment of fig2 and 3 . moreover , the glass retainer 12 used in the practice of the present invention is not always limited to either a one - piece or two - piece construction . the embodiment of fig4 shows a two - piece construction ( as does the embodiment of fig2 and 3 ) with the two split sections 12a &# 39 ; and 12b &# 39 ; sized so that the glass retainer 12 as a whole can be slightly oversized relative to the circumference of the rim 13a by , for example , a few millimeters when the circumference of rim 13a is 500 mm . in the example shown in fig4 after one of the split sections 12a &# 39 ; or 12b &# 39 ;, for example , the section 12a &# 39 ;, has been secured to the window frame 10 by means of the bolts and nuts 15 and 15a and the other section 12b &# 39 ; has not yet been secured , but merely fitted to the window frame 10 , at least one end of the other section 12b &# 39 ; will not be in end - to - end contact with the adjacent end of section 12a &# 39 ; as indicated by the chain - lined circle in fig4 . however , it can be brought into end - to - end abutment with the adjacent end of section 12a &# 39 ; when section 12b &# 39 ; and window frame 10 are fastened together by the bolts and nuts 15 and 15a with the elastic cushioning strip 11 consequently compressed inwardly , causing the glass plate 4 to be retained firmly to produce a fluid - tight window stay . where a relatively high rigidity is required in the glass retainer 12 , a four - segment glass retainer may be employed as shown in fig5 and 6 where the glass retainer 12 comprises four segments 12b1 , 12b2 , 12b3 , 12b4 , all generally l - shaped and , when combined together , constituting a glass retainer 12 of generally rectangular configuration . in the embodiments of fig5 and 6 the four segments 12b1 through 12b4 , each having a cross - section similar to that shown in fig3 are preferably so sized that the glass retainer 12 as a whole can be oversized as described above in connection with any one of the embodiments of fig4 and 9 . it should be noted that the embodiment of fig5 and 6 differ from each other in that while the glass retainer 12 in the embodiment of fig5 is split in a direction at right angles to the longitudinal axis of each side of the rectangular shape to provide the four segments 12b1 through 12b4 , the glass retainer 12 in the embodiment of fig6 is split in a direction diagonal to each side of the rectangular shape to provide the four segments 12b1 through 12b4 . in particular , in the embodiment shown in fig . 6 , when and after one of the segments , for example the segment 12b1 , has been secured to window frame 10 by means of the bolts and nuts 15 and 15a , and when the next adjacent segment 12b2 is to be secured to the window frame 10 by means of bolts and nuts 15a and 15b , one inclined end face fa of the segment 12b1 serves to guide the adjacent inclined end face fb of the segment 12b2 to allow the latter to wedge into the correct position when one of the bolts 15 which is adjacent to the inclined end face fb of the segment 12b2 is fastened by turning the associated nut 15a in the manner shown in fig . 7 . in the embodiment shown in fig8 the glass retainer 12 is similar to that employed in the embodiment shown in and described with reference to fig5 and 6 in that it comprises the four segments . however , two of the four segments 12c1 , 12c2 , 12c3 and 12c4 ( though the segment 12c4 is not illustrated in fig8 ), that is , segments 12c1 and 12c3 which are to be positioned on the extreme sides of the window stay , are generally u - shaped while the remaining segments 12c2 and 12c4 are straight . in addition , each of the straight segments 12c2 and 12c4 , which are to be positioned at the upper and lower extremities of the window stay , respectively , has its opposite ends inclined so as to converge at a point outside the window structure . thus , after the side segments 12c1 and 12c3 have been secured to the window frame 10 , the straight segments 12c2 and 12c4 are secured to frame 10 by being wedged between the opposite ends of the side segments 12c1 and 12c3 , as shown , as the bolts 15 are fastened . thus , when and after the straight segments 12c2 and 12c4 have been secured to the window frame 10 in the manner described above , the side segments 12c1 and 12c3 are biased in opposite directions away from each other to compress adjacent portions of the elastic cushioning strip 11 in contact with them . while the individual preferred embodiments of the present invention have been described herein , it has been found that , when the window stay acdording to the embodiments shown in fig2 and 3 which is supporting a laminated glass plate which is made of a transparent reinforcement sheet , 0 . 5 mm in thickness , sandwiched tightly between a pair of glass plates , one 10 mm in thickness and the other 3mm in thickness , was tested by dropping a concrete block of 12 . 28 kg in weight onto the glass plate from a specific height so as to simulate a speed of 64 . 4 km / hr , the window stay met the previously described requirements without the glass fragments separating or scattering although the glass plate was depressed . although the present invention has been fully described in connection with the various preferred embodiments thereof with reference to the accompanying drawings , it is to be noted that numerous changes and modifications can be readily conceived by those skilled in the art upon reading of the disclosure herein without departing from the spirit and scope of the present invention . by way of example , although in describing each of the preferred embodiments of the present invention , the glass plate and the associated component parts of the window stay have been shown and described as having a generally rectangular shape , they may have any other shape , for example , a square shape , a circular shape or an oval shape . accordingly , unless they depart from the scope of the present invention as defined by the appended claims , they should be construed as included therein .