Technical Field

A child safety lock for reversible hinges in windows, doors or traps is disclosed. The invention restricts the movement of the hinge in both the opening and the closing direction, and allows two half-open positions, corresponding to different opening angles of the hinge.

Child safety locks for use in reversible window hinges are primarily known from the Norwegian publications NO B 161748 and NO B 177239. A reversible window hinge with a safety lock is also described in the patent specification NO B 157112. Reversible hinges are commonly used in windows, and are located between the window frame and the window sash. Ordinarily, the hinge consists of an upper steering arm and a lower steering arm pivoted between a hinge part on the frame and a carrying arm attached to the sash. In most cases, the movement of the hinge is guided by a U-shaped profile fitted to the frame jamb. The reversible hinge window can be opened completely, and is then accessible for cleaning and maintenance on the outside pane of the window. When windows, doors or traps are fastened in this way, a device for holding the sash in a stable open position, e.g. for ventilation purposes, is needed. At the same time, the device should restrict the opening of the window, thereby preventing children from falling out. Thus, it is common to provide most reversible hinges with restrictors in order to prevent any unwanted movement of the hinge.

Background Art

The inventions described in the two publications NO B 161748 and NO B 177239 are both in compliance with the primary purpose of child safety restrictors, in so far as any reversible hinge window equipped with these devices automatically opens to a position at which the restricted opening device is engaged, and the distance between the window sash and the window frame is kept small enough to prevent child accidents. In the publication NO B 177239 it is maintained that the fitting described in NO B 161748 may sometimes fail to engage due to squeezing or friction in the safety lock. However, on closer scrutiny it would appear that the claim cannot be sustained. Both inventions are therefore to be considered as

efficient and reliable restricted opening devices. Nevertheless, the formerly known solutions have at least three other conspicuous weaknesses.

Firstly, the former solutions restrict the movement of the reversible hinge in one direction only, by limiting the initial opening of the hinge, whereas unintentional slamming of the hinged window, e.g. caused by a gust of wind, is still possible. Since the anti-slam function is strongly desirable, in practice this problem is normally solved by providing the reversible hinge with a separate fitting to be used independently of the child safety lock. This solution makes production of the reversible hinge more expensive, and it also complicates the operation of the hinge to such an extent that some end users, not formerly acquainted with the anti-slam device, may not be able to close the window when the fitting is in the locking position. A device that ensures child safety locking and anti-slamming in a single operation is disclosed in our Norwegian patent specification NO Bl 320116.

Secondly, only a single half-open ventilation position is available with the known solutions. As this position at the same time should prevent children from falling out of the window, the window opening will have insufficient ventilation in some situations, in particular during hot summer nights. The end user will then have to choose between a narrow, half-open ventilation position and a fully opened, unrestricted window. If the second alternative is chosen, the window might easily slam. Due to their design or location on the hinge, none of the formerly known solutions can allow more than one ventilation position. A new safety lock should accommodate the need for a second, larger ventilation position.

Thirdly, because of their design or dimension, several of the known devices are not suitable for the smallest hinge types. This is the case with the solution described in NO B 161748. Some other safety device must then be chosen when small window frames are mounted with the reversible hinge.

Disclosure of Invention

The present device provides simultaneous operation of the child safety lock and the anti- slamming feature in a single component. It also allows a second ventilation position, as described in the characterizing portion of the independent claim. When the device is used

together with a reversible window hinge, the locking device will be difficult to access for children, and if a child should try to open the window, the window is automatically blocked in a restricted hold-open position, thereby protecting the child from fully opening the window and eventually falling out, and also preventing the squeezing of fingers if the window slams. The device may, without changing its design or dimension, easily be used together with reversible hinges of various sizes. It is also possible to adapt the invention for use with several gadgets for manual operation, such as a push button mounted in the window frame, or a small component attached to the device itself, and acted on by pushing with a finger or by pulling a short cord.

Brief Description of Drawings

A detailed description of the best mode for carrying out the invention is given in the next part.

Reference is made to the following drawings, whereof

Figure 1 is a front view of a reversible hinge mounted in window frame, with the revolving part of the child safety lock attached to the frame hinge arm and the fixed part of the safety lock attached to, and partly hidden under, the lower steering arm of the hinge,

Figure 2 is a front view of the revolving part of the child safety lock,

Figure 3 is a front view of the fixed part of the child safety lock,

Figure 4 is a front view of the two parts of the child safety lock together with a closed reversible window hinge,

Figures 5-9 are front views of the same hinge components, where the opening degree of the hinge is varied.

Best Mode for Carrying Out the Invention

In figure 1, the upper part of a window sash 1 and part of a window frame 2 are shown. The window sash 1 is attached to a reversible hinge 3 on the right and left side of the window frame 2. The outer carrying arm 4 of the reversible hinge 3 has been provided with a pivot 5 for turning the window sash 1, and it is also pivotally connected to the upper steering arm 6 and the lower steering arm 7, whereof both arms 6, 7 are pivotally attached to the frame hinge arm 8 mounted in the window frame 2. The revolving part 9 of the device is shown pivotally connected to the frame hinge arm 8, on which a small protruding, cylindrical peg 10 limits the movement of the revolving part 9. The fixed part 11 of the device is mounted on the lower

steering arm 7, e.g. by welding, and stamped warts 12 or other protuberances on the side of the lower steering arm 7 facing the frame hinge arm 8 may be added to fit into corresponding holes on the fixed part 11, thereby ensuring the necessary precision during assembly of the hinge.

The revolving part 9 of the device, as shown in figure 2, is preferably made in one piece, can typically be made of metal by stamping, and should have a stamped hole 13 for pivotal attachment on the frame hinge arm 8. The thickness of the revolving part 9 must not exceed the distance between the visible side of the frame hinge arm 8 and the underside of the lower steering arm 7 when the arms are coupled together. The revolving part 9 can be attached to the frame hinge harm 8 with a rivet. In order to ensure that the revolving part 9 is turnable, the diameter of the rivet should be smaller than the diameter of the stamped hole 13. The revolving part 9 has a blade-shaped locking head 14 bounded by an underside 15, a front side 16, and an inner curve 17. The dimensions of the locking head 14 should allow for some wobbling when the locking head is placed in the first 18 or second recess 19 of the fixed part 11 of the device, shown in figure 3. When the reversible hinge 3 is closed, the underside 15 of the revolving part 9 should rest against the plateau 20 on the fixed part 11. Figure 4 shows the reciprocal arrangement of the fixed 11 and revolving 9 parts in this case. The inner curve 17 can have the shape of a simple circle segment. The movement of the reversible hinge will, however, be smoother when the inner curve 17 is composed of a lower 21 and an upper circle arc 22, having different radii of curvature and centres, and joining in a limit point 23 in the middle part of the inner curve 17. The revolving part 9 is also provided with a steering peg 24 which operates together with a sliding plane 41 on the fixed part 11 when the reversible hinge 3 is closed. In order to exclude positions that are unfavourable to the purpose of the device, the side 25 and the tooth 26 should function together with the cylindrical peg 10 on the frame hinge arm 8. Manual operation of the invention is facilitated by providing the revolving part 9 with an upturned lip 27 onto which an operational device, made from plastic or some other material, may be fastened. Preferably, the revolving part 9 may be provided with a protruding lever 28 to be acted on with a push button or some similar device from the window frame 2. The fixed part 11 must also have a curved sliding face 29 which receives collisions with the top point 30 on the revolving part 9 when the reversible hinge 3 is closed from a fully open position.

Below, a further description of the mode of operation of the device is given. In the revolving part 9, the distance from the rotational point in the centre of the hole 13 to the inner curve 17 increases continuously as we move from the lower top point 33 to the upper top point 35 via the limit point 35. This makes the following movement of the fitting possible. When the reversible hinge 3 is opened quickly from a fully closed position, the top point 31 on the fixed part 11 will collide with the inner curve 17 at a point on the lower circle arc 21, as shown in figure 5. As the reversible hinge 3 is opened further, the top point 31 pushes on the revolving part 9 with a force F which is tangential to a circle through the top point 31 and has its centre in the pivot 32 of the lower steering arm 7. The force F will then have a force component tangential to a second circle through the top point 31 with its centre in the hole 13. Because the force component points in the direction of movement for the top point 31 that is desirable if the device is to engage in the locking position, the top point 31 will climb along the lower circle arc 21 until the limit point 22 is reached. The top point 33 on the locking head 14 will then be very close to me curve 34 on the fixed part 11, and in order to prevent the top point 33 and the curve 34 from touching each other, thus interfering with the revolving movement of the device, the upper circle arc 22 may be given a radius of curvature and a centre independent of the lower circle arc 21, thereby ensuring that the rotation of the revolving part 9 continues to be determined by the contact with the top point 31 on the fixed part 11. The locking head 14 is guided into position in the first recess 18 of the fixed part 11, as seen in figure 6. Further opening of the reversible hinge 3 is then precluded. Slow opening of the reversible hinge will lead through the same cycle of events, apart from the fact that, due to gravity, the top point 31 may collide with a point on the upper circle arc 22 in the first place, and, therefrom, guide the locking head 14 into the first recess 18.

The position depicted in figure 6 also prevents the closing of the reversible hinge 3 from a half-open position, thereby providing an anti-slam feature for windows, doors or traps with this fitting. In this case, the force F works in the opposite direction, and may be unfavourable because the tangential force component of F will try to push the locking head 14 out of the first recess 18. Therefore, the inclination of the side 36 should be such that the distance from the pivotal point in the hole 13 of the revolving part 9 decreases during upward movement along the side 36, thus making any rotation of the locking head 14 physically impossible. The

same considerations as above apply when the locking head 14 is placed in the second recess 19, so that, in this case too, the reversible hinge 3 will engage in a locking position in which further opening or closing of the fitting is prevented, as shown in figure 7. Because the nether gap between the window sash 1 and the window frame 2 then usually is quite wide, the invention in this case functions solely as an anti-slam device. Also, the ridge 38 should be higher than the ridge 37 to ensure that the reversible hinge 3 enters a folly open position when the fitting is opened quickly. However, when the fitting is opened slowly, the locking head 14 should fall into the second recess 19, and the reversible hinge 3 will then enter a half-open, wide ventilation position. The reversible hinge 3 could also be placed in the half-open ventilation position through manual operation of the upturned lip 27.

When the reversible hinge 3 is closed from a fully opened position, it is desirable that the top point 30 of the revolving part is in a position where sliding along the curved face 29 is possible, as shown in figure 8. A cylindrical peg 10, colliding with the tooth 26 or the side 25 and thereby hindering further rotation of the revolving part 9, is placed on the frame hinge arm 8 in order to exclude unfavourable positions of the revolving part 9 during the closing of the fitting. When the reversible hinge is closed at normal speed, the top point 30 of the locking head 14 will hit the sliding plane 41 and slide upwards, as shown in figure 9. Also, inclined stamps 39, 40 may be introduced on the upper side of the frame hinge arm 8 and the underside of the lower steering arm 7 respectively, in order to prevent collision with the revolving 9 or the fixed part 11 of the device if any wobbling perpendicular to the frame hinge arm 8 is present in the fitting. In order to avoid operational disturbances that may arise from small particles or specks of dust in fittings that depend on gravity for their functioning, the revolving part 9 is provided with a small steering peg 24 which during closing hits the sliding plane 41 and turns the revolving part 9 into the folly closed position shown in figure 4. An appropriate initial configuration of the components of the reversible hinge 3 is thereby ensured by means of the mechanical forces in the device itself, and, when opened, the fitting will engage directly in the child-safe, half-open ventilation position in figure 6.