DK patent no. 168 406 discloses a lock assembly of the above type.

Although the functioning of this prior art lock mechanism is splendid, it is found that, when operat- ing the lock mechanism, the function is not perfect, when it comes to ergonomics, and likewise, the design could be improved.

It is hence an object of the invention to pro- vide a lock assembly having improved functionality with respect to ergonomics and likewise an improved design.

In order to fulfil the object the lock assembly according to the invention is characterized in that said first side of the handle bar has a radius of curvature of more than 6 mm, preferably more than 10 mm. Hereby the ergonomics of the handle bar is im- proved in that the fingers of the user grasping the handle bar for operating the lock will experience a relatively smooth surface with no projections or edges which could potentially chafe the fingers. A radius of curvature of less than 6 mm increases the risk of chafing the fingers, a risk which is virtu- ally inexistent by choosing a radius of curvature of

more than 10 mm. The first side of the handle bar may even have a radius of curvature of infinity, corre- sponding to a flat surface, but a slight curvature is normally to be preferred. A further advantage of a radius of curvature as indicated is that the dimen- sions of the lock assembly is minimal as the space available for the fingers of the user is improved compared to a lock assembly having a handle bar with projections. Another advantage of a handle bar with a curvature as indicated is that the dimensions of the lock assembly, i. e. the total height of the locking assembly including a covering, could be lowered con- siderably, while at the same time leaving the dis- tance from the first surface of the handle bar to the bottom of the lock assembly in principle unaltered, but due to the new design of the handle bar, without any risk of chafing ones fingers.

The handle bar may be massive, which would be the case with e. g. a handle bar made of wood, but ac- cording to an embodiment, the handle bar is hollow, as this saves material.

The end of the handle bar may be uncovered, ac- cording to an embodiment, however, the handle bar is provided with an end plate or plug, which closes the otherwise open end and thereby eliminates the risk of injury on the potentially sharp edges of the end of the handle bar and improves the visual impression of the handle bar.

The latch of the lock may engage with a reces- sion on a part of the window or door to which the lock is attached, however according to an embodiment, the lock assembly further comprises a striking plate, whereby a positive engagement is achieved and the

striking plate may conveniently be fitted at the de- sired position.

According to an embodiment, the lock assembly is of snap lock construction comprising a biasing means urging the latch in a locking direction, whereby it is achieved that the lock will engage automatically when the window or door is closed.

The operating member may be free to move to op- erate the lock assembly into or out of a locking po- sition; according to an embodiment the lock assembly further comprises a biasing means urging the operat- ing member in the locking direction.

Advantageously the lock assembly comprises stay means for retaining the latch in a disengaged posi- tion, whereby it is possible to inactivate the lock so opening and closing the window or door can be per- formed without locking.

According to an embodiment, the stay means com- prises a cam on the link member, which cam engages with a resilient tongue.

In the following the invention will be de- scribed in more detail by way of example and with reference to the drawing, in which Fig. 1 is a sectional view of a snap lock as- sembly according to the invention, Fig. 2 is a view in direction of arrow II in Fig. 1, Fig. 3 is a view corresponding to Fig. 1, but where the snap lock is in an open position, Fig. 4 is a sectional view of a prior art snap lock assembly, Fig. 5 is a perspective view of a striking plate according to the invention,

Fig. 6a and 6b depicts a combined barrel bolt bushing and sash stop element, and Fig. 7 is an end view of part of another em- bodiment of the snap lock assembly according to the invention.

The snap lock assembly according to Fig. 1 com- prises a snap lock mechanism, which in Fig. 1 is shown mounted on a window sash 1, which by means of a packing/weather strip 2 is sealed against a window frame 3. The assembly further comprises a striking plate 4, which is mounted on the frame 3 for engage- ment with the lock mechanism.

The lock mechanism comprises a latch 5 having a roller 6, which is mounted to be able rotate about an axis at right angles to the plane of the drawing. The latch 5 is connected to a link member 8 by means of a first hinge pin 7, and the link member 8 is in turn connected to a base member 10 of the lock mechanism by a second hinge pin 9. The latch 5 is further con- nected to an operating member 12 of the lock mecha- nism by a third hinge pin 11, whereas the operating member 12 is connected to the base member 10 by a fourth hinge pin 13 to be able to pivot about an axis perpendicular to the plane of the drawing.

The operating member 12 is provided with a han- dle bar 16 extending perpendicular to the plane of the drawing in Fig. 1 as can be seen in Fig. 2, which handle bar 16 can be gripped by the hand of a person, to thereby operate the lock mechanism and the window.

A first side 28 of the handle bar 16 has a radius of curvature of approximately 20 mm, which is found to provide a handle bar 16 having good ergonomics. A ra- dius of curvature of less than 6 mm is found to pro-

vide poor ergonomics, as there is a risk that the handle bar will chafe the user. The handle bar 16 is advantageously a profiled, hollow bar, which can be produced at a moderate expense and with a low con- sumption of material. Advantageously the handle bar 16 is profiled to engage with corresponding engage- ment means of the operating member 12, preferably for sliding engagement therewith as can be seen in Fig.

1.

The base member 10 can as shown be fastened to the window sash 1 by means of legs 15 protruding into holes provided in the sash 1. A particularly firm connection between sash 1 and base member 10 can be achieved by screwing screws into the hollow legs 15 from the opposite side of the sash 1. The operating member 12 is provided with a slot 17 in which the third hinge pin 11 is arranged. By means of a com- pression spring 18 the hinge pin 11 is biased to be in abutment with the end of the slot 17 as seen in Fig. 1. Further the operating member 12 is biased in counter clockwise direction by means of a coil spring 19.

When the lock is used as an ordinary snap lock, i. e. when the window sash 1 is shut, the window sash 1 will pass the striking plate 4. Hereby the latch 5 will be forced over the striking plate 4 against the pressure of the spring 18, as the hinge pin 11 is forced to away from the abutment at the end of the slot 17. When the roller 6 of the latch 5 has passed the front edge 21, the latch 5 will return to the locking position shown in Fig. 1, whereby the roller 6 engages with a locking surface 22 on the striking plate 4 and locks the sash 1.

Opening of the window is performed by forcing the operating member 12 in a clockwise direction in Fig. 1 about the fourth hinge pin 13 against the force of the coil spring 19, whereby the latch 5 with the roller 6 withdraws from engagement with the lock- ing surface 22. By engagement between a cam 25 on the link member and a resilient tongue 24 on the base member 10, the snap lock will stay in the open posi- tion as seen in Fig. 3, but it is easy to disengage the stay mechanism by light pressure on the operating member 12 in the closing direction.

The operating member 12 may be equipped with a cover, only indicated by the cross-section, having plane sides covering the operating member 12 and e. g. the connection to the latch 5.

The design of the handle bar 16 and the operat- ing member is such that the handle 16 conceals most of the operating member 12 when the lock is seen in direction A in Fig. 1, e. g. as the surface 30 of the operating member 12 is flush with the handle bar 16 and the base member 10, so the overall outline of the lock is very elegant and discreet, i. e. a nice de- sign.

A prior art snap lock assembly can be seen in Fig. 4. The prior art snap lock is of similar con- struction, but as can be seen a first side of the handle bar 116 has a projection 116', which is found to be a drawback with regards to ergonomics of the handle bar 16, as this projection 116'may chafe the fingers of a user operating the lock by gripping the handle bar. Further it can be seen that the clearance C'between the handle bar and the sash is smaller in this prior art lock compared to the clearance C of

the lock according to the invention as can be seen in Fig. 1. Alternatively the dimension of the clearance can be kept, meaning that it is possible to provide an operating member 12 with a handle bar 16 having a smaller overall height, making the lock assembly even more discreet and elegant. This is exemplified by an- other embodiment according to the invention shown in Fig. 7. In Fig. 7, the clearance C is equal to the clearance C'of the prior art lock assembly in Fig.

4, and consequently the overall height, Htotal, new/in Fig. 7 is smaller than the overall height, Htotal, prior, in Fig. 4.

A striking plate 4 is seen in perspective in Fig. 5. As can be seen the striking plate 4 is of practical and elegant design, as the front 31 and side walls 32 conceals the recess of the striking plate 4 and in the locked position of the window or door, the roller 6 of the latch 5 will also be at least partially concealed in the recess. Advanta- geously the striking plate 4 is provided with a slot for engagement with a screw for mounting on a frame part of the window or door, so that the position of the striking plate 4 is adjustable. Preferably the width of the recess of the striking plate 4 is some- what larger than the length of the roller 6 for en- gagement therewith to allow for inaccurate mounting of the lock assembly.

A separate barrel bolt bushing and frame stop element 33 may be provided, as can be seen in Fig. 6a and 6b, adapted for mounting on the frame. The ele- ment comprises a bushing 34 for a barrel bolt on the sash (not shown) for locking the sash relative to the frame, e. g. to enable polishing of the window pane.

The element further comprise a stop face 35 adapted to stop the pivoting movement of the sash, whereby a possible risk of damage to the locking mechanism is avoided.