In the construction of new buildings and in building renovation, glazing systems of prior art are installed in connection with balconies, said glazing systems being called for example balcony glazings. The sys- tems typically comprise an upper guide and a lower guide inside which necessary guide members are placed, single glass panes being sus- pended between said guide members. The guides typically extend horizontally and they are fastened to the structures of the building. By means of guide members it is possible to open and close individual glass panes, typically around a vertical rotation axis, and they can also be transferred aside along the guides, wherein several glass panes form a vertical stack, and the balcony is completely open.

The guide members comprise one or several hinging and locking pieces for each glass pane, by means of which the glass pane can be released from between the guide and turned aside. Typically the glass element is locked to the guide by means of a turnable tongue that is ar- ranged in a profile in the edge of the glass pane. The locking member can be arranged in either profile or in both profiles, but typically each locking member is controlled separately, wherein the locking of the element requires a great deal of work and the other locking member may be left unlocked.

Patent publication EP 1 085 153 discloses a locking apparatus in which locking latches moving in the vertical direction are placed in the upper and lower profiles of a glass element, said locking latches locking the element to the guides. The latches are connected together by means of a wire, which, when pulled perpendicularly to the glass plane, opens both the upper locking member and the lower locking member simul- taneously with one control movement.

The use of a locking apparatus of prior art that is based on pulling of a wire, is inconvenient for the user and furthermore, it is difficult to control the glass element, especially during the opening of the same because of the flexible wire that is used besides for opening the locking mem- bers also as a holding member. When the wire is pulled towards the user, the friction of the locking first makes the wire move further away from the glass element before the glass element opens. The detach- ment of the glass element from the locking and its halting after the opening cannot be completely controlled with the hand holding the wire, because the flexible wire functions in a spring-like manner, wherein the opening glass element is capable of hitting the hand, or there is a danger that it hits other parts of the body.

The primary aim of the present invention is to present a locking appa- ratus by means of which it is possible to lock a glass element firmly to the guides and by means of which the locking can be opened easily and safely with one control movement.

To attain this purpose, the locking apparatus according to the invention is primarily characterized in what will be presented in the characterizing part of the independent claim 1. The locking apparatus according to the invention is also primarily characterized in what will be presented in the characterizing part of the independent claim 10.

The other, dependent claims will present some preferred embodiments of the invention.

It is also an aim of one of the embodiments of the invention to arrange the locking of a movable glass element to the guides by means of locking members at least in two different points in such a manner that the locking members of different points can be controlled from one point. One locking member comprises at least two locking latches that are arranged to move in substantially opposite directions. The latches of the locking member are arranged to move substantially in parallel with the placement direction of the guides. Typically the latches of the locking member are arranged to move in the horizontal direction.

The control of the locking takes place advantageously by means of a turning movement of a control member, such as a rotary handle or a rotary knob, and the rotating movement resulting therefrom is trans- mitted to the locking member in which the latches move as a result of the movement. Said control member may be located either in the same structure with the locking member, or it can be placed apart from the locking member. Preferably, the control device is positioned in the same structure with the first locking member, and the control move- ment is transmitted to the second locking member by means of a wire, a belt or a bar. To adjust the length of the wire, it is advantageous to use a preferred adjustment structure, wherein the adjustment of the length of the wire can be conducted substantially without breaking the wire.

The control movement of the control device produces the rotating movement of a transfer member located in the locking member, which results in a horizontal linear movement of the latches. The movement of the latch in the opposite direction is typically produced by means of a spring-like member.

By guiding the locking member into an open position, the latches are positioned substantially inside the locking member, releasing the locking between the glass element and the guide. Thus, it is possible to turn open the glass element in which the locking apparatus in located.

Thereafter it is possible to slide the other glass elements of the glazing structure at the opening thus formed, and turn them into the open po- sition by utilizing the openings formed by the opened locking members in the structure.

It is easy and convenient to open and close a glass element equipped with a locking apparatus according to the invention, because the control member utilized for opening the locking, advantageously a sub- stantially stationary rotary handle or rotary knob also functions as a control device for the glass element. Thus, the glass element can be controlled accurately and precisely when the glass element is opened and closed, e. g. for that reason that the control member is not capable

of moving with respect to the glass element. An embodiment of the in- vention is especially safe in use, although an exposed wire is used.

The locking apparatus is implemented in such a manner that the locking apparatus cannot be opened by pulling a wire, but a handle or a knob must always be used. The apparatus is safe in the use of chil- dren as well.

In a preferred embodiment of the invention a large surface area is at- tained for the latches in the locking member positioned against the guide, since it is possible to use two or several latches in the locking member. Furthermore, locking controlled by means of one control member is easy to use, and in practice it eliminates the possibility of partial locking entirely, as all mutually controlled locking members are simultaneously either locked or open. As a result of the larger contact surface area and the act of preventing partial locking, the reliability of the locking apparatus is improved at the same time when the risk of the latches and the guide being damaged is reduced.

In preferred embodiments of the invention it is possible to place the turning device substantially freely in the structure of the glass element, and similarly in some embodiments the wire can be wound around the window area. Thus, the structure can be implemented so that it is ver- satile and fits well into the surrounding environment. In some embodi- ments it is possible to supplement the locking apparatus with a lock, and it is also possible to implement the opening mechanism on both sides of the glass element, for example by placing a handle on one side and a lock on the other, wherein such a locking apparatus can be used on both sides of the window structure.

In a preferred embodiment of the invention it is possible to adjust the length of the wire without breaking the wire, wherein the installation and maintenance of the locking apparatus can be conducted easily and rapidly. In the maintenance it is possible to adjust the function of the locking apparatus so that it functions accurately even though the length of the wire would change in use for example as a result of stretching.

In the following, the invention will be described in more detail with reference to the appended principle drawings showing a preferred em- bodiment of the invention, in which Fig. 1 shows a glass element containing a locking apparatus ac- cording to the invention, Fig. 2 shows an embodiment of a locking member, Fig. 3 shows an adjustment unit for adjusting the length of the wire, and Fig. 4 shows the groove structure of the adjustment member and the transfer member of the locking member.

A glass element 1 is arranged to move between guides 2 attached to structures, which guides are typically located up and down with respect to the glass element in accordance with the example, and they have a substantially U-shaped form. The guides are preferably manufactured by means of extrusion or drawing of aluminium.

On the edge of the glass element 1 to be arranged in the groove of the guide 2, for example on the upper and lower edge of the glass element of Fig. 1, a slide bar is arranged that comprises at least a slide struc- ture on the support of which the glass element is guided when moved in the guide. Typically the aforementioned slide structures are roll-like structures that reduce friction.

The glass element 1 according to the invention also comprises a locking apparatus 3 by means of which it is possible to lock the glass element in its place with respect to the guide 2. The locking apparatus 3 advantageously comprises locking members 4 according to Fig. 2 on the opposite edges of the glass element that are controlled by means of one control member 6.

In addition to the frame, the locking member 4 also comprises at least two latches 7 as well as a transfer member 9 and return means for moving the same. The latches 7 are arranged to be fastened to the guides 2 surrounding the glass element 1, typically to the upper and lower guides. Said latches 7 have advantageously bevelled ends, wherein when the glass element 1 is closed, the latch follows the lock housing formed by the edge of the guide 2, and the locking member 4 is locked to the guide, preferably independently. In a preferred em- bodiment of the locking member 4 the latches 7 are arranged to move linearly in relation to the frame of the locking member in opposite direc- tions with respect to each other. The transfer member 9 is arranged rotatable with respect to the frame, and said transfer member is con- nected to the latches 7 to transfer them.

The return means is arranged in connection with the latch 7 and the frame in such a manner that the return means tends to return the latch transferred with the transfer member 9 back to the initial position. Ad- vantageously, the return means is a latch-specific 7 spring-like member that is compressed when the locking member 4 is opened, and returns to the basic position when the locking member is closed.

The transfer of the latches 7 can be implemented in accordance within the spirit of the invention in various ways deviating from the example.

In the transfer it is possible to use for example various cogged wheel solutions, wherein the linear movement of the latches 7 in accordance with the invention is attained, but the structure becomes thus more complex when compared to that of the presented embodiment.

The transfer member 9 can be connected directly to the control mem- ber 6, such as a rotary knob or a rotary handle, or it is possible to transmit the control movement from the control member to the transfer member via a member 5, such as a wire, a belt or a bar that transmits tensile stress. In the embodiment of Fig. 1 a rotary handle 6 is ar- ranged in the lower locking member 4, and the transfer movement is transmitted to the upper locking member by means of a wire 5. In the solution according to the example the locking of the glass element 1 is not opened entirely if pulling is exerted on the wire 5 without turning the

handle 6. Thus, the upper locking is released, but the lower locking keeps the element 1 closed. Unintentional pulling may be exerted on the wire, for example when impact on the wire takes place. In the example the wire 5 travels directly from one locking member 4 to another, but it is possible to guide the wire along other routes as well, for example via the end of the glass element 1 and if necessary, inside the profiles, wherein it is not disturbingly on view and on the way.

In a preferred embodiment of the invention according to Fig. 3 it is pos- sible to adjust the length of the wire 5 between the locking members 4 without breaking the same. In the example, the length adjustment is ar- ranged in connection with the locking member 4 in which the control member 6 is also located. The end of the wire 5 is attached to an ad- justment part 8 and for its attachment it is possible to utilize various known methods, such as for example pressing the wire in between structures or passing the structure formed at the end of the wire into a suitable recess. In the example the adjustment part 8 is integrated in the control member 6. When an overlong wire 5 is used, the extra portion of the wire is wound around the adjustment part 8, advanta- geously to a surrounding groove structure formed in the adjustment part. Thereafter the adjustment member 8 is connected to the transfer member 9, wherein the symmetrical groovings on the abutting surfaces of the adjustment member and the transfer member are positioned against each other. The adjustment member 8 is locked to the transfer member 9 in such a manner that the members cannot move in relation to each other, wherein the length of the wire 5 remains in the adjusted state. The locking can be implemented for example by means of a screw.

The groovings in the adjustment member 8 and in the transfer member 9 can be implemented in various ways, but it is advantageous to form the groovings radially in accordance with Fig. 4, wherein the groove and the ridge are positioned between the central part and the outer edge of the member. In the embodiment according to the example, the grooves form a circle that ascends and descends in ridges of fixed shape and surrounds the central axis. It is advantageous to place the grooves as densely as possible, because in this way it is possible to

attain a large number of possible positioning alternatives, and thus the adjustment of the wire 5 becomes as accurate as possible. It is also possible to replace the groovings with different roughenings and friction surfaces, wherein the adjustment is nearly stepless and thus extremely accurate, but then, on the other hand, the mutual grip of the surfaces may be substantially impaired when compared to grooved solutions.

The length adjustment of the wire 5 conducted in said manner is very advantageous in installation and maintenance, because it is not neces- sary to cut and lock the wire separately.

In the following, the function of the locking apparatus 3 according to the above-described embodiment will be described in the process of opening and closing a window structure 1 of a glazing system.

The function of the locking apparatus 3 is controlled by means of a control member 6 that is advantageously a handle-like or knob-like ro- tary structure. It is also possible to use other structures, for example a lock as a control member 6. When the control member 6 is turned into an open position, the locking member 4 is also guided into the open position when the transfer member 9 rotates under the influence of either the control member directly or a power transmission 5, such as a wire transmission. As a result of the rotation of the transfer member 9, the latches 7 are positioned substantially inside the locking member 4, thus releasing the locking between the glass element 1 and the guide 2.

After the releasing of the locking it is possible to turn the glass element 1 in which the locking apparatus 3 is located into an open position i. e. in a direction deviating substantially from the direction of the guides 2.

Thereafter it is possible to slide the other glass elements of the glazing structure at the opening thus formed, and turn them into an open posi- tion by using the openings formed by the opened locking members 4 in the structure.

The turning of the control member 6 into a direction opposite to the one used in the opening process, or in a preferred embodiment the re-

leasing of the control member, makes the latches 7 of the locking members 4 turn into the locking position, i. e. makes the latches pro- trude from inside the locking member. The movement of the latches 7 is advantageously produced by a spring-like return means that has been compressed during the opening of the locking and tends to return into its basic position when the control member 6 is turned in the op- posite direction. The bevelling of the ends of the latches 7 in accor- dance with the example advantageously enables the closing of the glass element 1 solely by pressing the element towards the guide 2, wherein the control member 6 does not have to be turned separately in the locking.

By combining, in various ways, the modes and structures presented in connection with the different embodiments of the invention presented above, it is possible to produce various embodiments of the invention in accordance with the spirit of the invention. Therefore, the above-pre- sented examples must not be interpreted as restrictive to the invention, but the embodiments of the invention can be freely varied within the scope of the inventive features presented in the claims hereinbelow.