The present invention relates to magnetic latches suitable for use on gates or doors where automatic latching is required when the gate or door is displaced to a position at which it is to be latched. An actuator is provided for unlatching so that the gate or door can be opened, usually pivotally, away from its latching position.
The present invention in various embodiments offers new and useful alternatives to previously available options and indeed lends itself to embodiments which may incorporate security locks such as quality cylinder locks.
A significant development in magnetic latching and devices is the subject of the PCT International Publication W092/03631 on the basis of which U.S. Pat. No. 5,362,116 was issued to David Doyle and Neil Dunne, the contents of which are fully incorporated herein by reference. This invention has been assigned to the assignees of the present invention. The Doyle and Dunne invention relates to a vertically operating magnetic latch particularly for a swimming pool gate with a lost motion arrangement so that a latching pin, after manual retraction and after opening the gate, is retained in an elevated retracted position by spring biasing and the actuating mechanism does not apply downward load-imposing forces against the biasing spring.
While this device has been successfully exploited, the present invention has been conceived to offer novel inventive and alternative embodiments for different applications in a different form. Indeed the present invention may be applied to provide magnetic latching as an alternative to conventional striker plates with spring door latches and the invention may lend itself to versions incorporating locks.
Embodiments of the present invention are envisaged as extending both to manually actuatable versions (such as embodiments having rotatable rotary knobs or rotatable handles) but also extends to actuation by other means such as solenoids or electric motors permits actuation from a remote location. Of particular significance in these embodiments is the inherent characteristics of magnetic latching as demonstrated by the Doyle and Dunne prior patent whereby when a gate or door is swung to its closed position, in contrast to conventional gate latches where force is required to displace a spring biased latch pin initially away from a latching position prior to it entering into latching engagement, with Doyle and Dunne there is no such resistance. This is especially valuable in installations having an automatic door closing device.
The present invention is embodied in a self-latching device for latching, in a predetermined position, two members which are otherwise moveable relative to one another, the device comprising a latch arm and a retaining element which in use provides a latching shoulder for the latch arm to prevent relative movement of the members, at least one of the latch arm and the retaining element providing a magnetic field and the other having magnetic properties, 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 retaining element undergoing relative movement into a latching position under the influence of the magnetic field when the members are in the predetermined position, and then relative movement of the two members is substantially prevented by an 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:
(a) a resilient biasing element associated with the latch arm to bias it towards the retracted position, but with a biasing force on the latch arm which is less than the force imparted on the latch arm by the magnetic field when the members are located in the predetermined position;
(b) an actuator movably mounted on the housing and extending from the housing transversely to the path of displacement of the latch portion for receiving a displacement force 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;
(c) a connector for connecting the actuator and the latch arm to displace the latch arm from its latching position to its retracted position and to leave the actuator free to move relative to the connector; and
(d) a second biasing element for returning the actuator to its initial position on removal of the displacement force leaving the biasing element to maintain the latch arm and connector substantially in its retracted position, whereby when in the predetermined position the latch arm is displaceable under the magnetic forces against the biasing means to re-establish its latching position.
Implementation of the invention may be by including a lost motion interconnection between the actuator and the latch arm whereby no significant load is applied to the latching arm and its biasing element when in the retracted position.
In the subject invention, the actuator may be designed so as to be movable in a rectilinear, arcuate or rotary manner either in or transverse to a plane in which the latch arm is to be displaced.
A particular embodiment is one wherein the latch arm is mounted for reciprocation in a housing and the housing also mounts the actuator in the form of a rotary actuator which may include a conventional rotatable handle, with the option of providing one handle on either side of the device, for example to be disposed on either sides of a gate. Each handle might incorporate a locking mechanism such as a wafer lock or cylinder lock for security reasons. The housing might incorporate an alternative locking mechanism.
One embodiment provides a carriage with spaced guides along which mounting elements of the latch arm can slide, the latch arm incorporating a pin around which a helical compression biasing spring is mounted as the biasing means. In such an embodiment a torsion spring can be provided as the restoring means for the rotary actuating means (such as the handles).
As described with reference to an illustrated embodiment, the latch arm can take the form of a generally C-shaped carriage which moves in guides in the housing and the C-shaped carriage has lobes at its open ends for engagement with corresponding projecting elements associated with a barrel connected to a rotatable handle.
An alternative approach, however, is to provide the latch arm with a drum-like structure around which a flexible connection element extends. The arrangement is such that the element is extended and perhaps tensioned when the latch arm is in the latching position and rotation of the drum by the actuator causes the latch arm to be retracted. The arrangement is such that after movement of a gate (or door) to an open position, the biasing means retains the latch arm in its retracted position and tension previously applied to the flexible element is relieved so that no or only negligible load is applied against the biasing means.
The device may include an actuator for displacing the latch arm by remote actuation for remote gate opening control. However, larger markets are thought to be for directly operated gate latches having handles.
Embodiments of the invention can be formed into a volume, shape and configuration consistent with conventional cylinder lock door locks, i.e. within an envelope of about 15 cm×10 cm×5 cm.
Embodiments may have the magnet material provided by a permanent magnet having a remanence (residual flux density) of about 12 kilogauss and the latch arm has a pin having magnetic properties and of transverse dimension of about 8 mm, preferably sealed within the body of the retaining element and the latch arm then has a steel pin providing the latching portion and of a suitable grade of steel having magnetic properties.
In place of a rotatable knob or rotatable handle for actuating means, the invention lends itself to embodiments which are remotely actuated, for example electrically by the use of a solenoid arrangement or motor to cause rotation of the actuator for retraction of the latching arm.
Generally arrangements incorporate a lost motion interconnection between the actuator and the latch arm such that little or preferably no load is applied to the latching arm and its biasing means when in the retracted position.
Although significant markets for embodiments of the invention are perceived to be for gate locks incorporating key actuated mechanisms such as wafer locks or cylinder locks, embodiments may be simply no-lock latch mechanisms, or embodiments having an egress button on one handle and a lock on the other.
Embodiments can provide a lost motion effect by having an eccentric drive pin to be displaced upon lock actuation to displace an internal element from a retracted position (where it rotates freely upon handle rotation) to an extended position in which it engages with a collar to rotate the collar and the collar in turn displaces a carriage to retract the latch arm.
The term “comprising” (and its grammatical variations) as used herein are used in the inclusive sense of “having” or “including” and not in the sense of “consisting only of.” Other features and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings which illustrate, by way of example, the features of the invention.
In one embodiment, the present invention provides a magnetic latch comprising a first unit and a second unit adapted to be mounted on respective structures (such as a gate post and gate) which are relatively moveable with respect to each other but intended to be latched in a closed position; the first unit has a displaceable latch element displaceable along a first path and has biasing means to bias the latch element to a latching position, the latch element being displaceable against the biasing to a retracted position in operation; the second unit has a retractable element and engagement means for engaging in latching engagement a portion of the displaceable latch element of the first unit when in the latching position, the retractable element being retractable along a second path transverse to the first path, the second unit further having biasing means to bias the retractable element to a retracted position; the magnetic latch has magnetic means associated with the displaceable latch element and with the retractable element so that in use when the structures are in the closed position, the juxtaposition of the latch element and the retractable element causes magnetic forces to displace the latch element against its biasing to establish the latching engagement, and the magnetic latch has retraction means selectively operable to retract one of the latch element and the retractable element whereby the requisite juxtaposition for magnetic attraction between the latch element and the retractable element ceases, thereby permitting the structures to be moved from the closed position.
In another embodiment, the invention may be defined as a magnetic latch having first and second units adapted to interengage in use in latching engagement to hold a moveable structure (such as a door) in a closed position relative to another structure (such as a door post), the latch having a magnetic arrangement in the first and second units to cause components thereof to be displaced to establish latching engagement under magnetic forces when the components are in juxtaposition for latching at the closed position, the first unit having
(a) a component of the magnetic arrangement biased towards a position in which magnetic attraction occurs for establishing latching engagement with the second unit,
(b) an actuator operable to displace the component against the biasing to cause removal of the magnetic attraction for unlatching, and
(c) a latching structure to co-operate in latching engagement with the second unit, and the second unit having a component of the magnetic arrangement provided in a retractable element which is biased towards a retracted position away from a latching position in which latching engagement with the latching structure of the first unit can occur.Xx
In one form the actuator is movable along a second path transverse to the first path of movement of the retractable element of the second unit and the component is a permanent magnet. Furthermore the second unit may have its retractable element movable in a direction at right angles to the first path, and of an material which is attracted to the magnet.
However both components of the magnetic arrangement could be permanent magnets with opposite poles adjacent to one another is the latching position.
In another embodiment, the first unit may have a rotatable mounted permanent magnet, and the second unit has a permanent magnet associated with the retractable element, the actuator being adapted to rotate the magnet of the first unit so that magnetic repulsion occurs with the magnet of the second unit to bias the retractable element towards its retracted position and unlatching occurs.
Biasing can generally include resilient biasing, for example using a compression spring either alone or as an aid to gravity or alone or in combination with magnetic biasing. Embodiments include using magnetic biasing.
In one important application, the magnetic latch has its first unit adapted to be mounted on a gate with a horizontally displaceable actuator (which may be moved by a rotatable handle or otherwise) and which mounts a magnet, which is normally in a projected position under biasing, and the second unit has a vertically retractable magnetically attractable latching element, biased vertically away from a complementary latching element of the first unit but arranged to be magnetically attracted by the magnet to establish latching but moveable under its biasing when the actuator is driven to retract the magnet.
It will be appreciated that the prevent invention lends itself to various embodiments.
In an illustrative embodiment described hereinafter with reference to the accompanying drawings, a particular form will be given where the first unit is adapted to be mounted on a gate and retraction for unlatching is provided for by the use of rotatable handles on both sides of the gate or if preferred just one side, the first unit carrying a high coercitivity permanent magnet which is biased to a projected positing for latching purposes.
The first unit also has a projection defining a rigid cavity for receiving in latching engagement under magnetic forces the retractable element of the second unit.
In one embodiment biasing is by a helical spring but other spring arrangements could be used within the scope of the invention and indeed the assistance of gravity could be adopted. For example, the embodiment described later with reference to the drawings could be installed in an inverted position where gravity aids the retractable element to then descend away from the latching cavity.
Although the magnetic arrangement can be achieved with one component having a high coercivity magnet and the other being of magnetic material such as steel, both components could contain magnet with appropriate polarity for attraction purposes.
In a simple application, the invention may be embodied in arrangements that purely provide for a manually operable system for achieving an unlatching whereby the gate or door can be opened. However embodiments of the invention lend themselves to remote actuation, for example by electro-magnetic actuation. This might be particularly valuable for security gates or the like. Although the illustrative embodiment does not include security locks, such features can be included if desired in a conventional manner for the handles.
It would be appreciated that embodiments of the invention can be particularly or advantageous with gates and doors of a general nature, although embodiments of the invention could be subject of adaptations, particularly to meet the safety requirements of swimming pool gates and the like. Regulations for swimming pool gates require that they are outwardly opening, and that the location of the displacement element for opening or unlatching the gate must be out of reach of a child of less than a certain height.
Thus, an adaptation of the embodiment shown in the drawings for swinging gates could be to omit the front handle and have a plain casing and to mount the latch well below the upper portion of the gate so it can only be actuated by leaning over the gate and reaching down to open the gate.
The magnetic latch shown in the drawings is particularly suitable for mounting on a conventional pivotal gate or door but the unit could also be installed on a sliding door.
The invention will be further exemplified with reference to the accompanying drawings of which:
The gate latch generally shown in
The latch module has a front casing 13 and a rear casing 14 adapted to be mounted on opposite sides of gate post. Front and rear handles 15 and 16 are provided and a security cylinder lock 17 is provided for each handle for independent locking purposes.
The components are shown in more detail in
An actuating barrel 33 (as shown in more detail in
As best seen in
The rear end of the barrel 33 has a groove 39 for accommodating the corresponding arcuate tab 40 from the rear handle so that rotary motion is transmitted to the barrel 33 when the latch is assembled and either handle is rotated. A similar groove 39A is provided on the front of the barrel for the arcuate tab 40 of the front handle. The barrel assembly includes upper and lower ears 41 at the ends of pivotal arms 34 which are mounted on pivot pin 35 with a C-shaped spring clip 36 fitted over the arms 34 to bias them radially inwardly so that recess 37 in the inner periphery of each arm rest on lobes 39A of a rotor 39. The recess provides a detent function to define positively the position shown.
A middle portion of the barrel has an L-shaped bracket 43 for retaining end pins 64 of a torsion spring 66 (not shown in
Referring now to
However, when the lock is locked, the rotor 39 is rotated and the lobes 39A disengage the arms 34 which displace inwardly under the pressure of the spring clip 36. If the handle 15 is displaced, the ears 41 do not engaged the lobes 63 of the carriage and the carriage does not move.
The components of the latching block 12 are more clearly shown in exploded view in
The components comprise an L-shaped mounting plate 50 adapted to be secured to a post by screws passing through apertures 51 on an end face. The mounting plate has dovetail section tracks 52 for engaging slidingly with complimentary shaped grooves on the rear of a latch body 53. The latch body has a central cavity for accommodating a high strength magnet 54 which is held in position and the cavity sealed with suitable sealant when a cover element 55 is secured in place. The element 55 has a suitable shaped aperture 56 having a latching function when engaged with the tip of latching pin 25.
Main fixing screws 67 (shown more clearly in
Although not shown in the drawing, the rear of the front housing 11 is provided with spaced mounting lugs having cylindrical bores through which the mounting screws 67 also extend to achieve assembly.
As and when the gate is returned to its closed position, the latch pin 25 again becomes aligned with the receiving cavity 56 and is then attracted under the strong magnetic field to move to the left thereby compressing the biasing spring 26 and sliding the carriage 32 to the left so that the configuration of
Reference will now be made to
This embodiment shows the detail for mounting a conventional six pin cylinder lock 17 in each handle. The lock is inserted into the handle barrel with a lateral projection from each cylinder engaging in a corresponding cavity. A retaining plate 19 is inserted to close the cavity and secured by fixing screws 19A. Each cylinder lock has a projecting tab 18 being of rectangular cross-sectional shape for conventional purposes and of a length to suit engagement in respective rotor elements 27 and 28 to be associated with the actuating barrel 33 as described in more detail below.
Each handle is secured to the respective casing by a spring clip 69.
In this embodiment, the form of the mounting plate 20 is slightly different form, as illustrated, and the end wall 23 incorporates an integral security housing projection 28.
In this embodiment, the barrel 33, in place of the pivotal spring arms 34 of the first embodiment, has a moulded collar 29. Within the collar is mounted a tongue 57 which is secured in cooperating relationship to the front and rear rotors 27 and 28 which are secured, as described below, by two plain roll pins 59.
Referring now to
The collar 29 is rotatably mounted around the barrel and in the position shown in
In place of the cylinder lock shown in
The barrel 33 is simplified as an integral moulding incorporating ears 41 and at a forward end region a pair of grooves 33A for engaging with the projecting tabs 40 from the rear of the front handle for rotating the barrel. The rear portion of the barrel has further grooves 33B for similar engagement with the projecting tabs 40 from the rear handle 16. Upon assembly the barrel is located with the ears 41 located behind the lobes 63 of the carriage 31 and the embodiment operates by direct actuation of the carriage.
Referring now to the fifth embodiment of
Referring now to
In a similar way to previous embodiments, when the door or gate is returned to its closed position, the configuration of
Referring now to the adaptation of
Referring now to the seventh embodiment of
Push button 118 has a gear rack 119 engaging a pinion 122 having a horizontal axis aligned with the axis of the latch pin 25. The button 118 is slidably mounted in the housing of the device and is biased by a spring (not shown) to its outward or projecting position. When the button is depressed, rack 119 rotates pinion 122 which carries a crown gear 120 in constant mesh with a gear 121 on the barrel 33 so that the barrel rotates. Upper ear 41 engages the upper lobe 63 of the carriage 31 to retract it and the latch pin 25 to the position shown in
After opening of the gate on which the device is mounted, and upon release of the button, the barrel and button return to an initial position, corresponding to that shown in
When the gate is re-positioned to its closing position, the magnet in the receiving unit (not shown) attracts the latch pin to the latching position shown in
The magnetic door latch illustrated in the
The handle unit 210 has a support body 214 consisting of a plate 216 and a cross wall 218 adapted to be mounted by screws onto a door 262 and supporting the mechanisms of the unit. A forked tongue 220 projects forwardly from the cross wall 218 and defines within it a square shape latching cavity 222 in the upper region and a central zone 224 for receiving a retractable high coercivity permanent magnet 226.
The permanent magnet 226 is sealed for protection in a magnet carrier 230 which is attached to a retractable carriage 232 having at the end remote from the magnet C-shaped end fitting 236. The carriage 32 is biased to the left hand position shown in
Rotabably mounted operating handles 242 are secured to the mounting plate 216 and a drive plate 244 is secured to the inner shaft portion associated with the handles whereby on rotation of either handle in either an anti-clockwise or clockwise direction one of the ears 246 of the drive plate engages one of the end tips 236 to retract the carriage 232 to the position shown in
The second unit 212 comprises a mounting plate 250 for fixing the unit to a door post 260 and providing a body of 252 for mounting a vertically movable latching pin 228 which is biased to its upward retracted position by helical biasing spring 254. The pin's movement is limited by its latching head 256 in the upper position abutting an end wall of the mount 252, the upper end of the spring having a collar 258 with the helical compression spring acting between the collar and the wall of the body 252.
Number | Date | Country | Kind |
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2004900908 | Feb 2004 | AU | national |
This application is a continuation-in-part of pending application Ser. No. 11/034,487 filed on Jan. 13, 2005.
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Number | Date | Country | |
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Parent | 11034487 | Jan 2005 | US |
Child | 12144164 | US |