The present invention relates to a locking device for fastening of a light dome to a skylight window sash according to the introductory part of claim 1.

To shield off a window portion positioned more or less horizontally in a flat roof it is know to fasten a dome-shaped weather shield or light dome to a sash of the window portion to form a skylight or roof window. The sash is embedded in a frame, which is secured to the roof, the sash and frame together with a pane embedded in the sash forming a window portion of the window or skylight. The purpose of the weather shield is to divert water from rainfall, leaves etc. from the window by means of gravitational forces. The weather shield is typically attached to the sash by means of fasteners in the form of ordinary and/or standard threaded screws or bolts, an oblong part of each screw or bolt being guided through a peripheral hole of the weather shield. A head part of the screw or bolt abuts an upper surface of the weather shield, the oblong part extending through the hole of the weather shield to be fas- tened in corresponding bores of the sash.

The weather shield is typically transported separately from the sash and mounted on the sash after the window portion has been mounted in the roof. A standard tool such as a screwdriver corresponding to slots of the screws or bolts is used to fasten the screws or bolts through the holes of the weather shield and into the sash. This means, of course, that a similar standard tool can be used to release the screws or bolts, making it possible for a burglar to easily and with little preparation gain access to the window portion, the burglar only needing to carry a standard screwdriver. A solution to this problem has been disclosed in DE 8617125

Ul, which describes a burglar-proof locking device with features corresponding to the introductory part of claim 1. This locking device is used to fasten a two-layer light dome to a roof. A locking member in the form of an ordinary screw is positioned in the bottom of a hole in a profile with an interior thread. A cap with a corresponding exterior thread is then screwed into the hole, a head part of the cap comprising sloping sides, which eventually abut an upper surface of the light dome, covering the hole and screw in order to prevent the insertion of a standard screwdriver into the hole to protect the window from burglars. The sloping sides of the cap make it difficult to engage a standard tool, such as a wrench, with the cap in order to turn it. However, the cap comprises a notch or slot for a special tool, which can thus be engaged with the cap in order to rotate it such as to release it. Because of the rotatable cap with sloping sides, the locking device of DE 8617125 Ul has the drawback of being somewhat complicated and voluminous. Further, although the sides are sloping, there is still at risk of a burglar being able to get a decent grip on the cap by means of, for example, an ordinary wrench. Below the sloping sides a strong and rigid supporting construction needs to be provided in order to ensure that the sides can withstand radial forces on the cap. Also, in order to fasten the light dome, first one fastener, i.e. the screw, needs to be fastened, and subsequently, a second fastener, i.e. the cap, needs to be fastened. In other words, two different tools are needed, and the time needed for fastening the light dome is at least doubled in relation to the conventional fastening method described above. During repairs, cleaning or dismounting the window it is equally problematic to release the light dome.

Another locking device for fastening of a light dome is known from DE 29710526 Ul, which however does not disclose the use of special tools for release of the locking device.

On this background it is the object of the present invention to provide a locking device according to the introductory part of claim 1, which is more secure and easier to attach and detach with a special tool. To meet this object the locking device according to the present invention is characterized by the features according to the characterizing part of claim 1.

With the locking device according to the invention only the locking means itself needs to be fastened in order to fasten a light dome; no second fastener is necessary, the cap already being attached to the locking means before fastening. This is achieved since the special tool rotates the locking means itself, not the cap. Thus, the time needed for the fastening or releasing operation by means of a special tool is significantly reduced. The locking device according to the invention is smaller and less complicated and thus cheaper to manufacture. Further, because the cap surrounding the visible or engageable part of the locking device is freely rotatable in relation to the locking means, a burglar will not be able to release the locking device by means of an ordinary tool, e.g. a wrench. Thus, the locking device is also made more secure.

The dependent claims define preferred embodiments of the invention according to claim 1.

The invention will be explained in detail in the following by means of examples of embodiments with reference to the schematic drawing, in which

Fig. 1 is a perspective view of an embodiment of a skylight window, which can be provided with one or more burglar-proof locking devices according to the present invention,

Fig. 2 is a cross-sectional view of the window according to Fig. 1,

Fig. 3 is a detail of a cross-sectional view corresponding to that of Fig. 2, the window being provided with a fastener,

Fig. 4 is a perspective view of the fastener shown in Fig. 3,

Fig. 5 is. a side view of the fastener of Fig. 3, Fig. 6 is an end view of the locking device of Fig. 3 seen from the right of the fastener as shown in Fig. 5, and

Fig. 7 is an end view of the fastener of Fig. 3 seen from the left of the fastener as shown in Fig. 5.

Fig. 8 is a perspective view of an embodiment of a locking de- vice according to the present invention, in which a snake-eye tool has been engaged,

Fig. 9 is a sectional side view of the locking device of Fig. 8 taken along the line IX-IX of Fig. 8,

Fig. 10 is a perspective view of the locking device of Fig. 8 sec- tioned as in fig. 9,

Figs 1 and 2 show different views of a skylight or roof window intended to be mounted in or on a flat roof. In the present context flat roofs are defined as roofs having an inclination in relation to horizontal of less than about 15°. The window comprises a rectangular window portion i, which is able to rotate about a horizontal axis positioned along a bottom of the skylight (to the lower right in Fig. 1 and to the right in Fig. 2). The window portion 1 is installed in a flat roof 2 and comprises a sash 3 positioned in a frame 4, which are both made up of extruded, hol- low PVC profiles. In other embodiments the frame and sash may be in the form of for example extruded aluminium profiles, and they may comprise wooden parts.

The sash 3 comprises a bottom 3a, a top 3b and two side (not shown) sash members and encloses a windowpane 5 with two layers of glazing sandwiching a layer of gas to provide insulation glazing. The frame 4 comprises a bottom 4a, a top 4b and two side frame members, of which only one side frame member, 4c, is shown (in Fig. 1). The bottom sash member 3a is rotatably connected to the bottom frame member 4a by means of two hinges (not shown) defining a rotation axis. A weather shield or light dome in the form of an acrylic or polycarbonate dome 6 is attached to the sash 3 to protect the window portion 1. Lifting and rotating the sash 3 and dome 6 about the rotation axis by means of a chain operator 23 embedded in the top frame member 4b provides movement between an open and a closed position of the win- dow. The chain. operator 23 may be driven automatically and may be radio-controlled. Supporting the dome portion 6 are longitudinally extending sealing projections or weather strips 7, 8, sealing the sash 3 against the dome portion 6, cf. Figs 2 and 3.

The weather shield 6 comprises peripheral holes 9. In Figs 1 and 2 a non-burglar-proof fastener 10 has been inserted through one of the peripheral holes 9, the fastener 10 being shown in Figs 3 to 7. Note that in the present embodiment similar, not shown fasteners 10 are to be inserted in some of the remaining holes 9 of the weather shield 6 as shown in Fig. 1. In the present embodiment the fastener of one hole 9 on each side of the weather shield 6 is furthermore to be replaced with a locking device 10a (not shown in Figs 1 and 2), i.e. a total number of four locking devices is preferably to be provided. However, any number between one and all of the holes 9 may be provided with a locking device 10a. The locking device 10a is an embodiment of the locking device according to the present invention and is shown in Figs 8 to 10.

The fastener 10 is shown in more detail in Figs 3 to 7. It comprises a head part 11 connected to a connection part 12, the outer dimensions of which correspond to the inner dimensions of the holes 9. The connection part 12 extends into a first fastening means in the form of a clog-shaped radial protrusion 13a with an engagement member in the form of an upwards projecting tip end 14 of said clog shape. The head part 11 comprises grip means in the form of two finger depressions 15, 16. The connection part 12 comprises second fastening means in the form of two oppositely positioned snap locks 17, 18. The fastener 10 is integrally molded from Zytel 80633, i.e. acrylic with 33% glass.

In Figs 2 and 3 the fastener 10 is shown in a locked condition in which it fastens the weather shield 6 to the sash 3. The head part 11 has a lower, flat surface, which is positioned abutting an upper surface of the weather shield 6, the connection part 12 extending through a hole of the weather shield 6 into the bottom sash member 3a. As is visible in Fig. 3 the peripheral hole of this figure is formed in an upwardly protruding dimple 20 of the weather shield 6; the same is the case for all the peripheral holes 9. In the locked position the tip end 14 of the radial pro- trusion 13 engages a corresponding engagement means of the sash 3 in the form of a downwards protruding longitudinally extending bead 19. The bead 19 extends in the entire circumference of the sash 3, forming a tip end of a likewise longitudinally extending part of the sash, making it somewhat resilient in an upwards direction. When inserting the fastener into the hole 9 the snap locks 17,

18 are positioned abutting a lower surface of the weather shield 6. Hereby, the lower surface of the head part 11 and the snap locks 17, 18 at all times cooperate to secure the fastener in the hole. To release the fastener 10 from the hole, the snap locks 17, 18 will need to be released from the inside of the weather shield 6.

The finger depressions 15, 16 are adapted such that in the fastened position of the fastener 10 as shown in Figs. 2 and 3 rain water and snow are allowed to readily pass the head part 11. Between the dimple 20 and the lower surface of the head part

11 a soft plastic gasket member 21 is provided. This gasket member 21 is somewhat resilient, providing for a corresponding resiliency of the fastener 10, which is made, use of when fastening or releasing the fastener 10 as is explained in more detail below. In the present embodiment the gasket member 21 is secured, i.e. glued, to the dimple 20; in other embodiments it may form part of the fastener 10.

The tip end 14 is released from the bead 19 of the bottom sash member 3a by means of rotation of the fastener 10. Rotation can be carried out without the use of a separate tool placing a thumb and an index finger of one hand in the finger depressions 15, 16, respectively. The fastener 10 can be rotated either way about the connection part 12, whereby the tip end 14 passes the downwards protruding bead 19, and the fastener 10 and weather shield 6 is released from the sash 3.

From the released position rotating the fastener 10 to snap back to the original, locked position is done in a corresponding manner. The combined resilience of the gasket member 21, longitudinal sealing members 7, 8, bead 19 and fastener 10 itself makes it possible for the tip end 14 to pass the bead 19 with a snapping sound and/or sensation telling a user that the fastener 10 has been fastened or released. The gasket 21 and sealing members 7, 8 also ensure that the weather shield 6 is watertight in the area of the hole in the weather shield 6.

The fastener may comprise a further radial protrusion corresponding to and protruding oppositely to the radial protrusion 13 to pro- vide for a stronger attachment, as is the case with the locking device 10a, which is described in more detail in the following. This would prevent the fastener/locking device from tilting when being rotated to or from a locked position.

The burglar-proof locking device 10a shown in detail in Figs 8 to 10 is a preferred embodiment of the present invention. As will be clear from the following description, the general principles underlying the form and construction of the locking device 10a in most aspects correspond to those of the fastener 10 described above. Members of the locking device 10a corresponding in function to a member of the fastener 10 are provided with similar reference numbers and a subsequent consecutive letter.

Referring now to Figs 8 to 10 the locking device 10a comprises a locking member 30 having a first end 31 and a second end 32, which are positioned along a longitudinal axis A of the locking member 10a and connected by a connection part 12a, the outer dimensions of which correspond to the inner dimensions of the holes 9 of the weather shield 6. The first end 31 projects outwardly downwards from the locking device 10a and comprises a locking means 13b, 13c, which are described in more detail below.

The second end 32 of the locking member 30 provides an engagement or gripping means in the form of a snake-eye notch 33 comprising two holes or "snake eyes" 15a, 15b, which are adapted for engagement with a special tool in the form of a snake-eye tool 34 with a corresponding snake-eye projection 35, which in Figs 8 to 10 have been inserted into the snake-eye notch 33. The snake-eye tool 34 is preferably delivered together with the window and is not sold separately. The snake-eye notch 33 is surrounded by a head part or cap 11a with a centre aperture 36 allowing for insertion there-through of the snake-eye tool 34 for rotation of the locking device 10a, the cap 11a otherwise covering the second end 32 of the locking member 30.

The cap 11a is made from a durable material, preferably zinc, and is freely rotatable about the longitudinal axis A in relation to the locking member 30. The latter is achieved in that the cap 11a comprises an inwardly extending circular circumferential projection 39, which engages a corresponding circular circumferential slot 40 provided by the locking device 10a, the cap 11a being freely rotatable in the slot 40. The slot 40 is formed between a lower surface of a head 38 (of engagement member 37, cf. below) and an upper surface of the locking member 30. The upper surface of the locking member 30 is the surface of a circular disc 41 with a diameter corresponding to an inner diameter of a mushroom-shaped and hollow covering part 42 of the cap 11a, the covering part 42 covering the second end 32 of the locking device 10a to prevent burglar access. Hereby, entrance of dirt into the cap lla is prevented. A gasket member 21a for abutting an upper surface of the weather shield or light dome 6 is provided abutting a lower surface of the disc 41. The circumferential projection 39 extends into a cylindrical part of the cap lla, the cylindrical part defining the centre aperture 36 of the cap lla. In the present embodiment the snake-eye notch 33 is provided by means of a separate engagement member 37 comprising a head 38 and a longitudinal part 43, the latter extending coaxially into and being fixed, preferably glued, to the locking member 30. The snake-eye notch 33 is provided on top of the head 38. The engagement member 37 and the locking member 30 are moulded as separate parts from Zytel 80633.

The locking means 13a is adapted to rotate into engagement with the above-mentioned corresponding locking means 19 of the sash member 3. For this purpose, the locking means 13a of the first end 31 the connection part 12a comprises two oppositely projecting, clog- shaped, radial protrusions 13b, 13c for being snap-locked, by means of a 90° axial rotation, to the corresponding locking means 19 of the sash 3. As with the fastener 10 the radial protrusions 13b, 13c each comprises an upwards-projecting outer tip 14a, 14b for engaging the corresponding locking means 19. Thus, the present embodiment of a locking device comprises two radial protrusions 13b, 13c, but it may in other embodiments comprise only a single such protrusion corresponding to the fastener 10. Accordingly, the corresponding locking means of the sash 3 preferably comprises two downwards protruding, longitudinally extending beads, each similar to the bead 19 described above, but provided on opposite sides of the hole 9.

Comparing with and referring to Fig. 3, the head part lla has a lower, flat surface, more specifically the gasket member 21a, which in the locked position abuts the upper surface of the weather shield 6, the connection part 12 extending through a hole 9 of the weather shield 6 into the sash 3. The locking device 10a is fastened and released in a matter similar to the fastener 10 by means of rotation; however, in this instance it is rotated by means of the snake-eye tool 34 and cannot be rotated by hand. When fastened, the only accessible parts of the locking device

10a are the cap 11a and the snake-eye notch 35. Thus, if the cap 11a is rotated, the locking member 30 is not rotated; and rotation of the locking member 30 without use of the snake-eye tool 34 is safely prevented. The engagement member of the fastener and/or locking device and the engagement means of the sash can be provided in other forms. The tip ends may for example turn opposite ways compared to the embodiment in the drawings, still providing a suitable snap lock. The engagement member could also be provided in the form of an ordinary thread. Further, the locking device 10a could be provided with snap locks corresponding to the snap locks 17, 18 of the fastener 10.