The invention relates to improvements in windows, comprising a casing and a so called doublβlinkβd side- hung casement consisting of two window frames, each one of which has at least one windowpane mounted therein. Windows that are arranged to be turned in order to make their external face accessible from within a room, often are pivot-hung, i.e. they are arranged for pivotal movement about horizontal shafts disposed in the casing. Often, this is a disadvantageous arrangement since part of the window, when pivoted, enters into the room where curtains and objects placed on the window sill interfere with the pivotal movement.

Other types of turnable windows are mounted in fittings at either side of the window. In accordance with one prior-art arrangement, the fitting consists of a pivotable arm mounted on the casement and of two essentially parallel articuled arms secured in respectively the pivotable arm and the casing. Guides positioned at one pair of the window corners travel in grooves formed in the casing.

This arrangement is advantageous in that owing to the window being guided in said grooves, its pivotal movement takes place externally of the casing and thus no part of the window enters into the room. The fitting including its various parts, the grooves in the casing and the guides do, however, make the construction a rather expensive one and the mounting thereof is time- consuming and requires specially trained fitters, entailing further not insignificant expenses. The subject invention suggests a device which may be mounted in conventional side-hung windows of the kind defined in the introduction hereto and which with the aid of a double hinge at the free longitudinal frame edge

allows the external face of the window to be turned completely over. The characterizing features of the device are defined in the appended claims. The device is very easy to mount and is of a simple and inexpensive construction.

The invention will be described in closer details in the following with reference to the accompanying drawings, wherein

Fig. 1 is a perspective view of a part of a window equipped with the device in accordance with the invention,

Figs. 2 and 3 are plan views of the two window frames of the casement in different positions of pivotement, Fig. 4 is a horizontal cross-sectional view through the casing with a built-in window blocking mechanism, and

Fig. 5 illustrates said blocking mechanism schematically in a different position.

The drawing figures illustrate a conventional window including a casing 1 in which is side-hung a casement 2 comprising two window frames 3, 4, each mounting a single windowpane 5, 6.

The main component of the improved device in accordance with the invention is a fitting 7 which is pivotally supported on a casing-mounted hinge 8. For the sake of simplicity, only one fitting 7 and one hinge 8 are shown in the drawing figures, since any additional fittings and hinges designed to mount and support the window are of identical construction and arrangement. The fitting 7 is secured on the inner longitudinal edge-side 9 of the two window frames 3, 4 by means of bolts or screws 10, the latter being of the kind having a head thereon. These bolts or screws pass through their respective one of recesses 11 formed in the fitting 7 so as to penetrate into the window frames 3, 4. The bolts or screws 10 abut by means of their heads against the fitting 7 but are not tightened firmly against the

latter. The recesses 11 extend in pairs and in opposite relationship, up to their respective one of the vertical edges 12 and 13, respectively, of the fitting 7.

In addition, a locking member, which in accordance with the illustrated embodiment consists of a spring- biased pin 14, 15 is arranged in each window frame 3, 4. When in their outer, spring-actuated position, the pins 14, 15 extend through corresponding holes formed in the fitting 7, for the purposes of keeping the window frames 3, 4 in adjoining relationship and thus preventing them from being pulled apart.

On the longitudinal edge-side 16 of the window frames, i.e. the edge side opposite to longitudinal edge- side 9, the window frames 3, 4 are interconnected by means of a double hinge 17.

The device in accordance with the invention allows the window frames 3, 4 to be pulled apart in two ways. By depressing the spring-biased pin 14 to dislodge it from its associated hole in the fitting 7 and disengaging the two bolts or screws 10 in the window frame 3 from the recesses 11 it becomes possible to separate the window frames 3, 4 in the manner illustrated in Fig. 2, in which position the inner faces of the associated windowpanes 5, 6 become accessible in the same manner as in the case of a conventional, linked casement.

If, on the other hand, the spring-biased pin 15 is depressed in the same manner, the bolts 10 in the window frame 4 may be disengaged from their associated recesses 11 and the window frame 4 be pivoted in the manner illustrated in Fig. 3, in which position the outer face of the window frame 4 is turned inwards, towards the window opening.

The device in accordance with the invention thus makes it possible to pivot a basically conventional linked casement in a simple manner, allowing its external face to become accessible from the window opening, for instance for the purpose of cleaning the windowpane.

Since the pivotal movement of the casement 2 is effected entirely outside of the window opening there is no need to take the trouble of pulling the curtains out of the way or removing plants or other objects from the window sill.

In accordance with one further development of the invention the fitting 7 is equipped with a blocking mechanism. The latter comprises a pivotable arm 18, one end of which is hingedly mounted on the fitting 7 whereas its opposite end is provided with a locking pin 19, see Figs. 4 and 5. The blocking mechanism further comprises a rotatable spindle 20 in which a number of recesses 21 are formed. The rotatable spindle 20 may be turned clockwise by means of a knob 22 against the action of a spring 23. By turning the spindle 20 with the aid of the knob

22 from the angular position illustrated in Fig. 5 to the position illustrated in Fig. 4, it becomes possible to turn the window unimpededly outwards from the closed position. As soon as the knob 22 is released, the rotatable spindle 20 will turn in the opposite direction over a part of one turn, during which opening movement the locking pin 19 will slide into engagement with the immediately following recess 21, thus preventing further turning outwards of the window. By again turning the knob 22, the operator once more frees the locking pin 19 and he can then pivot the window to the desired open position, release the knob 22 once more and then allow the locking pin 19 to snap into the next closest recess 21. The rotatable spindle 20 preferably cooperates with a locking means of some kind, not illustrated in the drawing figures but having the function of blocking the rotatable spindle 20 in the position illustrated in Fig. 4 following complete turning of the knob 22 in the clockwise direction. This arrangement makes it easier to pivot the window from an open position to a closed position or vice versa, because there is no need to

simultaneously use one hand to operate the knob 22. After closing or opening of the window the rotatable spindle 20 could be freed from its blocked position by simply turning the knob 22 in the opposite direction. The device in accordance with the invention is not limited to the embodiment illustrated and described in the aforegoing but could be varied in many ways within the scope of the appended claims. This is true as regards the design of the fitting as well as of the blocking mechanism.