GB2145461A

GB2145461A - Magnetically operated latch

Info

Publication number: GB2145461A
Application number: GB08322559A
Authority: GB
Inventors: Roger Conington Richards
Original assignee: Individual
Current assignee: Individual
Priority date: 1983-08-22
Filing date: 1983-08-22
Publication date: 1985-03-27
Also published as: GB8322559D0; GB2145461B

Abstract

Application of an external magnet to the correct part of door 1 will draw slider 5 into recess 8, thereby withdrawing latch bolt 4 from the recess in the door frame. On removal of the external magnet the bolt 4 is shot again by reason of the attraction between steel collar 10 and magnet 5A in the slider. <IMAGE>

Description

SPECIFICATION Magnetically operated latch This invention relates to a magnetically oper ated latch.

According to the present invention, there is provided a magnetically operated latch for securing to a door leaf, the latch including a body housing an extendable latch bolt coup led to a slidable member of such a material that is attractable to a magnet, the arrange ment being such that when a magnet is placed in the vicinity of said slidable member, it wll be drawn towards the magnet, thereby withdrawing the latch bolt into said body, and there being means to cause the latch bolt to extend again out of said body when said magnet is removed from the vicinity of said slidable member.

The slidable member can be another mag net. In this case, the means to cause the latch bolt to extend again out of the body can be a member either of magnetically soft material or having a magnetism that is attractive to the magnetic slidable member in order to draw the slidable member in a direction opposite to that in which it is drawn by the first mentioned magnet, once this latter magnet has been removed from the vicinity of the slidable member.

The latch bolt can be coupled to the slidable member by means of lever that is pivoted at one end to the latch bolt and at the other end to the slidable member. The latch bolt can be arranged to slide in a direction that is at right angles to the direction of sliding of the slidable member.

For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawing, in which: Figure 1 is a diagrammatic cross-sectional view of a magnetically operated latch mounted on a door leaf, Figure 2 is a cross-sectional view at right angles to the view shown in Fig. 1, and Figure 3 is a rear view of the door latch.

The drawing shows a magnetically operated latch that is designed to be fixed to a door leaf of, for example, an article of furniture.

The latch is shown in Figs. 1 and 2 attached to a door leaf 1, the latch including a body 2 secured by screws 3 to the door leaf 1, the body 2 housing an extendable latch bolt 4 that is slidable within the body 2 in a direction so as to be able to extend from or be withdrawn into the body 2.

The latch bolt 4 is coupled to an elongate slidable member 5 by means of a curved lever 6 which is pivoted at one end 6A to one end of the slidable member 5 and at its other end 6B to a part of the latch bolt 4 remote from the part that can extend out of the body 2. As shown, the latch bolt 4 is arranged to slide in a direction that is at right angles to the direction of sliding of the member 5.

A small magnet 5A is incorporated in the slidable member 5 so that when a magnetic key 7 is applied in the vicinity of the slidable member 5 as shown, on the outside of the door leaf 1, the slidable member 5 is magnetically attracted towards the magnetic key 7 and this draws the end 6A of the lever 6 downwardly as viewed in Fig. 2, which causes the end 6B of the lever 6 to move towards the right as viewed in Fig. 2, thereby dragging with it the latch bolt 4, which is then withdrawn into the body 2. A recess 8 is provided in the door leaf 1 into which the slidable member 5 can penetrate.Thus, when the door leaf 1 is closed and the magnet 7 is applied as shown, the latch bolt 4 will be withdrawn from the door jamb 9 and the magnetic attraction between the magnets 7 and 5A is sufficient to enable the door leaf 1 to be drawn open by pulling on the magnetic key 7.

A means is provided to cause the latch bolt 4 to extend again out of the body 2 when the magnetic key 7 is removed from the vicinity of the slidable member 5, this means preferably being a steel collar 10 or a collar of similarly magnetically soft material set into the rear face of the latch. It will be seen that, upon removal of the magnetic key 7, the smaller magnet 5A of the slidable member 5 will be attracted back towards the collar 10, thereby returning the latch to the condition shown in Figs. 1 and 2 where the latch bolt 4 extends from the body 2. It will be appreciated that the collar 10 could be formed as a magnet set to attract the magnet 5A but, in all cases the magnetic key 7 is the strongest magnet.

Apart from the two magnets illustrated and the collar 10, all other parts of the latch are made of non-magnetic material (aluminium, brass, plastics material etc.,). The magnetic key 7 could be mounted in, for example, a wooden holder.

It will be appreciated that the present latch provides a child proof safety lock in the kitchen and throughout the house and on such furniture as would be defaced if a conventional lock with key hole etc., were fitted.

In addition, the lach is useful wherever it is necessary to conceal the whereabouts of a locked door, the magnetic key only remaining adhering to the outside the door leaf 1 for as long as it is required to keep the door unlatched.

It will further be appreciated that the latch body 2 can be constructed in such a way that it could be recessed completely into the rear of a door leaf or even completely enclosed within a door leaf, with a lateral slot being provided for the latch bolt 4 in the door leaf.

Claims

1. A magnetically operated latch for securing to a door leaf, the lach including a body housing an extendable latch bolt coupled to a slidable member of such a material that is attractable to a magnet, the arrangement being such that when a magnet is placed in the vicinity of said slidable member, it will be drawn towards the magnet, thereby withdrawing the latch bolt into said body, and there being means to cause the latch bolt to extend again out of said body when said magnet is removed from the vicinity of said slidable member.

2. A magnetically operated latch as claimed in claim 1, wherein said slidable member is made of magnetic material.

3. A magnetically operated latch as claimed in claim 2, wherein said means to cause said latch bolt to extend again out of said body is a member either of magnetically soft material or has a magnetism that is attractive to said slidable member in order to draw the slidable member in a direction opposite to that in which it is drawn by the first mentioned magnet, once this latter magnet has been removed from the vicinity of the slidable member.

4. A magnetically operated latch as claimed in claim 1, 2 or 3, wherein said latch bolt is coupled to said slidable member by means of a lever that is pivoted at one end to the latch bolt and at the other end to said slidable member.

5. A magnetically operated latch as claimed in any one of the preceding claims, wherein said latch bolt is arranged to slide in a direction that is at right angles to the direction of sliding of said slidable member.

6. A magnetically operated latch as claimed in any one of the preceding claims, wherein the first mentioned magnet is present and is in the form of 9 magnetic key which ia to be applied to the outside of a door leaf in the vicinity of the magnetically operated latch in order to open the door.

7. A magnetically operated latch, substantially as hereinbefore described with reference to the accompanying drawing.

8. A door leaf incorporating a magnetically operated latch as claimed in any one of the preceding claims.