| GB737764A | 1955-09-28 | |||
| FR2571752A3 | 1986-04-18 | |||
| GB893945A | 1962-04-18 | |||
| GB198116A | 1923-05-31 |
| 1. | A safety door lock for a domestic appliance or the like, comprising a suc tion clamp attachable to a surface of the appliance adjacent to the door thereof and an arm projecting from the clamp to overlie the door, thereby preventing the door from opening to a significant extent. |
| 2. | A safety door lock according to Claim 1, wherein the clamp is operable by a removable lever so that, after the door lock is secured in position adjacent to the door, the lever may be removed and placed out of reach of a child, thereby preventing the child from removing the lock and gaining access to the interior of the appliance. |
| 3. | A safety door lock according to Claim 1 or 2, comprising an extension member pivotally attached to the free end of the arm and rotatable from a first position alongside the arm to a second position substantially at rightangles to the arm, whereby the lock may be attached to a side or top surface of the appliance. |
| 4. | A safety door lock according to Claim 1,2 or 3, wherein the suction clamp is of the type having a flexible diaphragm with an embedded plate having a rod extending therefrom, such that, when the diaphragm is against a flat surface, an out ward pull on the rod creates a region of reduced pressure between the diaphragm and the surface, so that atmospheric pressure holds the clamp firmly against the surface. |
| 5. | A safety door lock according to Claim 4, wherein the rod is connected to a cam which can be rotated from a rest position to an operative position in which the rod has been lifted outwardly, the transition between one position and the other being such that the cam snaps between the two positions. |
| 6. | A safety door lock according to Claim 5, wherein the cam has a pair of faces substantially at right angles to each other and with a relatively short transition sur face between the faces. |
| 7. | A safety door lock according to any preceding claim, wherein the arm is formed as a channelshaped member. |
Background to the Invention Every year small children are killed and injured by domestic appliances, espe- cially tumble dryers and washing machines, as a result of climbing inside the machines and becoming trapped. In addition, it has been known for children to open a washing machine while the wash cycle is operating, because the safety lock is inoperative, thus causing the release of wash water. This is not only damaging to the room in which the machine is sited, it can also be dangerous to the child if the water is at a high tempera- ture.
Although the manufacturers of such appliances make considerable efforts to im- prove safety systems, there are two main problems with this. Firstly, although newer appliances might offer additional safety features, there are still many older appliances in use which do not have such features, and secondly, the safety features tend to make operation of the appliances more difficult and therefore makes them less attractive to those who do not have children.
Modification of existing appliances to render them safer to small children is diffi- cult, because it would have to be carried out by a capable technician; it is not generally something which can be done by the user of the appliance, both because of the skill re- quired to effect the modification and because the manufacturer's warranty might be invalidated by changes made by an unauthorised person. This makes modification a costly option not available to many users.
The present invention seeks to overcome these disadvantages.
Summary of the Invention According to the invention, there is provided a safety door lock for a domestic appliance or the like, comprising a suction clamp attachable to a surface of the appliance adjacent to the door thereof and an arm projecting from the clamp to overlie the door, thereby preventing the door from opening to a significant extent.
The suction clamp may be of the general type used for example in the handling of sheet materials such as glass, and is preferably operable by a removable lever so that, after the door lock is secured in position adjacent to the door, the lever may be re- moved and placed out of reach of a child, thereby preventing the child from removing the lock and gaining access to the interior of the appliance.
The lock may be provided with an extension member pivotally attached to the free end of the arm and rotatable from a first position alongside the arm to a second position substantially at right-angles to the arm, whereby the lock may be attached to a side or top surface of the appliance, for example when there is insufficient space on the front panel thereof to permit attachment of the device. The extension member then extends from the arm to overlie the door, again preventing it from opening.
The suction clamp is suitably of the type having a flexible diaphragm with an embedded plate having a rod extending therefrom, such that, when the diaphragm is against a flat surface, an outward pull on the rod creates a region of reduced pressure between the diaphragm and the surface, so that atmospheric pressure holds the clamp firmly against the surface. The rod is connected to a cam which can be rotated from a rest position to an operative position in which the rod has been fitted outwardly, the transition between one position and the other being such that the cam snaps between the two positions. This is typically effected by providing the cam with a pair of faces substantially at right angles to each other and with a relatively short transition surface between the faces, for example a rounded-off corner.
The body of the lock is suitable formed of a plastics material and the extension member, where provided, can also be of plastics material. The arm, and the extension member where provided, are suitably formed as channel-shaped members for strength.
The lock of the invention is simple to install but holds securely in use, without the need for any permanent modification of the appliance. It can be readily attached and removed to any suitable surface of the appliance adjacent to the door. While the invention has been described with reference to domestic appliances, it can be used to secure other doors, for example a hinged door of a medicine cabinet, or even to pre- vent opening of a window of an upper floor without the need for a permanently-fitted
lock. The lock offers in these circumstances the additional security of being openable without a special key in the event of an emergency, the action of the suction clamp be- ing difficult for a child, even with the key, but easy for an adult with any convenient tool.
Brief Description of the Drawings In the drawings, which illustrate an exemplary embodiment of the invention: Figure 1 is a perspective view of the lock ; Figure 2 is an enlarged partial sectional view of the lock ; Figure 3 is an elevational view of an appliance having the lock of Figures 1 and 2 fitted to the front thereof ; and Figure 4 is a top plan view of a portion of an appliance having the lock of Figures 1 and 2 fitted to the side thereof.
Detailed Description of the Illustrated Embodiment Referring first to Figures 1 and 2, the lock comprises a moulded plastics body 1 having integrally moulded therewith an arm 2 which extends to one side of the body and has an extension member 20 pivotally attached adjacent to the end thereof. The body 1 has an open face 3 on the underside thereof across which is seated a rubber diaphragm 4. As may be seen from Figure 2, the diaphragm has embedded centrally therein a steel plate 5 having a steel rod 6 extending upwardly therefrom. The rod 6 passes through the body 1 and is attached to a bifurcated cam 7 located on the upper surface of the body by means of a pivot pin 8 passing through a transverse hole in the pin and through holes in the body of the cam. The upper part of the cam 7 is provided with a bore 9 therein which can receive therein the end of a key 10 (Figure 1), permit- ting the cam to be rotated from the unlocked position shown in Figures 1 and 2 for- ward to a position in which the bore 9 is horizontal, relative to the views of Figures 1 and 2.
As the cam 7 rotates its dimensions and the position of the pivot pin 8 are such that the rod 6 is pulled upwardly and is held in this position by the cam snapping over from its first position about the rounded corner 7a of the cam. The lifting of the rod 6 in turn lifts the centre of the diaphragm 4, causing the pressure beneath the diaphragm to reduce, thereby clamping the lock to the surface as described hereinbefore. A ta-
pered coil spring 11 surrounds the rod 6 within the body 1 to assist in releasing the dia- phragm when the cam is rotated to the release position.
Figure 3 illustrates the use of the lock on an appliance, shown schematically.
The appliance 12 has a front face 13 in which is set a hinged door 14 opening outwards of the appliance. The lock is attached to the front face 13 immediately adjacent to the door, and with the arm 2 thereof extending over the door, thereby preventing the door from being opened.
In Figure 4, the appliance illustrated is of the type having a door 15 which is co- extensive with at least a part of the front face 16 of the appliance, such that the lock cannot be attached to the front face. In this case, the lock is attached to a side panel 17 of the appliance, with the extension member 20 first rotated to its open position in which it extends generally normally to the arm 2. The lock is then positioned so that the extension member 20 extends adjacent to the outer surface of the door 15, and is clamped so that the door cannot be opened.