Developments for magnetic latches

• US 20050210938A1
• Filed: 05/17/2004
• Published: 09/29/2005
• Est. Priority Date: 03/24/2004
• Status: Abandoned Application

• Current Assignee: DD Group Pty., Limited
• Original Assignee: DD Group Pty., Limited
• Inventors: Doyle, David, Dunne, Neil, Calabria, David, Clark, Anthony John
• Application Number:
  US10/848,040
• Publication Number:
  US 20050210938A1
• Time in Patent Office: Days
• US Class Current: 70/276
• CPC Class Codes: E05B 15/0093 Weight arrangements in locks; gravity activated lock parts E05B65/5292, E05B77/06 take precedence
• CPC Class Codes: E05B 17/2034 moving pivotally or rotatively
• CPC Class Codes: E05B 53/003 flexible
• CPC Class Codes: E05B 65/0014 to prevent opening by children E05B13/00 takes precedence; child-proof container closures B65D50/00
• CPC Class Codes: E05C 19/163 a movable bolt being held in the striker by a permanent magnet
• CPC Class Codes: Y10T 70/7057 Permanent magnet

Abstract

A self-latching device is disclosed which is arranged to latch, in a predetermined position, two members which are otherwise movable relative to each other such as a hinged gate. The device comprises a latch arm having a latch element and a manual actuator mounted on one of the members and which is movable between a latched and a retracted position, by upward manual displacement of the actuator, and a retaining element incorporating a permanent magnet mounted on the other member. The latch arm is spring biased into the retracted position but, when in the predetermined position, is caused to move by the magnetic field generated by the magnetic into the latched position wherein any substantial relative movement of the two members is prevented by the latch arm engaging the retaining element. A lost motion connection is provided between the actuator and the latch element either by being in the form of a flexible line or through a multiple element linkage such that upon latching, the actuator falls to a rest position without applying any substantial load on the latch element.

Claims

1. A self-latching device for latching, in a predetermined position, two members which are otherwise moveable relative to one another, the device comprising:

(i) a latch arm; and

(ii) a retaining element which in use provides a latching shoulder for the latch arm to prevent relative movement of the members;

(iii) at least one of the latch arm and the retaining element providing a strong magnetic field and the other having magnetic properties;

(iv) the latch arm being arranged to be displaceably mounted on a first of said members and the retaining element being arranged to be associated with the second of said members, the latch arm and the retaining element undergo relative movement into a latching position, when the members are in the predetermined position, under the influence of the magnetic field substantially to prevent relative movement of the two members by engagement portion of the latch arm and latching shoulder interengaging, and the latch arm being displaceable under applied force away from the retaining element to a retracted position so that the members may be moved apart;

the device further comprises;

(v) a biasing means arranged to bias the latch arm towards the retracted position, the biasing means being arranged to impart a force on the latch arm which is less than the biasing force imparted on the latch arm by the magnetic field when the members are located in the predetermined position;

(vi) actuating means arranged to be mounted on the first of the members in association with the latch arm to respond to an actuating input to displace the latch arm from its latching position to its retracted position, whereby the two members may be moved apart away from the predetermined position and, on removal of the actuation input, the actuating means is free to return to its initial position and the biasing means maintains the latch arm substantially in its retracted position, and when the members return to the predetermined position, the latch arm then being displaceable under the magnetic forces against the biasing means to re-establish its latching position; and

(vii) the actuating means substantially avoiding load being applied to the latch arm in all its positions by either;

(a) a multi-link structure having a degree of lost motion at each link, or

(b) a flexible element which is tensioned to absorb slack when the latch arm is displaced to its retracted position and when displacement actuator input is removed the flexible element buckles.

2. A device as claimed in claim 1, wherein the latch arm is mounted for vertical reciprocation in a housing and the housing also mounts the actuator which as in the form of a manually gripped element.

3. A device as claimed in claim 2, and further comprising a cylinder lock for locking the actuating means.

4. A device as claimed in claim 1, wherein high strength magnet material is sealed in a body of the retaining element and the latch arm has a steel pin of magnetic characteristics.

5. A device as claimed in claim 1, wherein the actuating means is adapted to be remotely power operated.

6. A self-latching device for latching, in a predetermined position, two members which are otherwise moveable relative to one another, the device comprising:

(i) a latch arm mounted in a housing for vertical reciprocating motion; and

(ii) a retaining element which in use provides a latching shoulder for the latch arm to prevent relative movement of the members;

(iii) at least one of the latch arm and the retaining element providing a strong magnetic field and the other having magnetic properties;

(iv) the latch arm being arranged to be displaceably mounted on a first of said members and the retaining element being arranged to be associated with the second of said members, the latch arm and the retaining element undergo relative movement into a latching position, when the members are in the predetermined position, under the influence of the magnetic field substantially to prevent relative movement of the two members by engagement portion of the latch arm and latching shoulder interengaging, and the latch arm being displaceable under applied force away from the retaining element to a retracted position so that the members may be moved apart;

the device further comprises;

(v) a biasing means arranged to bias the latch arm towards the retracted position, the biasing means being arranged to impart a force on the latch arm which is less than the biasing force imparted on the latch arm by the magnetic field when the members are located in the predetermined position;

(vi) actuating means in the form of a manually gripped actuator element mounted on the housing of the latch arm to respond to an actuating input to displace the latch arm from its latching position to its retracted position, whereby the two members may then be moved apart away from the predetermined position and, on removal of the actuation input, the actuating means is free to return to its initial position and the biasing means maintains the latch arm substantially in its retracted position, and when the members return to the predetermined position the latch arm is then displaceable under the magnetic forces against the biasing means to re-establish its latching position;

(vii) the actuating means substantially avoiding load being applied to the latch arm in all its positions by a flexible element which provides a lost motion effect and is tensioned to absorb slack when the actuator element commences upward motion from the latching position in which it normally is buckled.

7. A device as claimed in claim 6, further comprising a cylinder lock for locking the actuating means, and associated with an upper support in the housing for supporting the actuator element when released.

8. A device as claimed in claim 6, wherein high strength magnet material is sealed in a body of the retaining element and the latch arm has a steel pin of magnetic characteristics.

9. A device as claimed in claim 6, wherein the actuating means is adapted to be remotely power operated.

10. A self-latching device for latching, in a predetermined position, two members which are otherwise moveable relative to one another, the device comprising:

(i) a latch arm mounted in a housing for vertical reciprocity motion; and

(ii) a retaining element which in use provides a latching shoulder for the latch arm to prevent relative movement of the members;

(iii) at least one of the latch arm and the retaining element providing a strong magnetic field and the other having magnetic properties;

(iv) the latch arm being arranged to be displaceably mounted on a first of said members and the retaining element being arranged to be associated with the second of said members, the latch arm and the retaining element undergo relative movement into a latching position, when the members are in the predetermined position, under the influence of the magnetic field substantially to prevent relative movement of the two members by engagement portion of the latch arm and latching shoulder interengaging, and the latch arm being displaceable under applied force away from the retaining element to a retracted position so that the members may be moved apart;

the device further comprises;

(v) a biasing means arranged to bias the latch arm towards the retracted position, the biasing means being arranged to impart a force on the latch arm which is less than the biasing force imparted on the latch arm by the magnetic field when the members are located in the predetermined position;

(vi) actuating means in the form of a manually gripped actuator element mounted on the housing of the latch arm to respond to an actuating input to displace the latch arm from its latching position to its retracted position, whereby the two members may then be moved apart away from the predetermined position and, on removal of the actuation input, the actuating means is free to return to its initial position and the biasing means maintains the latch arm substantially in its retracted position, and when the members return to the predetermined position the latch arm is then displaceable under the magnetic forces against the biasing means to re-establish its latching position;

(vii) and a multi-link structure in the actuating means providing a lost motion effect whereby on the latch arm is substantially avoided and the actuator means, when released, is supported by the housing.

11. A device as claimed in claim 10, further comprising a cylinder lock for locking the actuating means, and associated with an upper support in the housing for supporting the actuator element when released.

12. A device as claimed in claim 10, wherein high strength magnet material is sealed in a body of the retaining element and the latch arm has a steel pin of magnetic characteristics.

13. A device as claimed in claim 10, wherein the actuating means is adapted to be remotely power operated.