Patent Grant
8127578
The present invention relates to latches for gates and doors and more particularly is concerned with a latch of the type wherein a displaceable element (usually called a tongue) has a latching shoulder to engage with a striker arm with respect to which it is relatively moveable, the tongue having a striker surface adapted to engage with the striker arm to displace the tongue to permit engagement of the striker arm behind the latching shoulder. Typically, the biasing of the tongue will be under gravity, for example through a pivotal mounting and there is an arrangement to permit the tongue to be displaced to release the striker arm whereby a gate or door is then released to be moved relative to a gate post or door post.
The field of the invention extends to devices having spring biased tongues as well as gravity biased tongues and, in addition, extends to tongues which are both gravity and spring biased.
Various forms of latches and, in particular, gravity latches, have been previously proposed such as U.S. Pat. No. 6,058,747 (Doyle) and U.S. Pat. No. 6,513,351 (Clark), both of which are assigned to the assignees of the present invention. These two US patents disclose specific developments in the field of latches for gates and doors. Other known prior latches in the field of those referred to as references in the printed specifications of the two US patents mentioned above. The prior art listed comprises:
U.S. Pat. No. 6,058,747 (Doyle et al) has a disclosure of a gravity latch having an enshrouded tongue and the lock mounted to be accessible from the front face. The disclosure includes a rear actuator unit adapted to be mounted on the opposite or rear face of a gate post so that, subject to any unlocking required of the rear unit, the tongue can be raised by the rear actuator to release the striker arm so that the gate may be opened from the rear side.
U.S. Pat. No. 6,513,351 (Clark) is a development with cylinder locks provided in front and rear units and respectively key operated to rotate a locking element into and out of a locking position. In the locking position the gravity biased tongue is locked in a retaining position in which the associated striker arm is held in position.
The prior published specifications referred to above are mentioned as an illustration of the background but in doing so, no admission is made that any of the specifications form part of the common general knowledge in Australia or any other geographical region.
In this specification, unless the context requires otherwise, the word “comprising” is used in the non exhaustive sense and further features may be present in the arrangement described.
The present invention is directed to new and useful alternatives to known arrangements.
According to a first aspect of the invention there is broadly provided a latch comprising:
(a) a housing in which
(b) a displaceable latching element is mounted to be rotatable around a first axis of rotation from a latching position towards an open position in which a striker arm independent of the latch is released, and
(c) the latching element having a latching shoulder adapted to retain the striker arm when engaged behind the latching shoulder and having an engagement surface adapted to be engaged by the striker arm when the striker arm and latching element are brought together to rotate the latching element and for permitting relative movement of the striker arm to adopt a position behind the latching shoulder,
(d) a locking element for locking the latching element and mounted to be rotatable around a second axis of rotation between a locked position, in which the latching element is restrained from moving, and an unlocked position in which the latching element is free to be moved, one of the axis of rotation being displaced from the other axis of rotation in a direction radial to the other axis,
(e) the locking element being biased towards the locking position,
(f) the latching element being biased towards an open position,
(g) the latching element having an interference portion which operates when the latching element has been displaced away from the latching position to prevent the locking element returning to its locking position,
(h) whereby when the arm engages the latching element, the latching element is rotated thereby releasing the interference portion from the locking element whereby the locked element is released to move into the locking position so that a self locking arrangement is provided.
According to a second aspect of the invention there is broadly provided a latch comprising:
According to a third aspect of the present invention, there is broadly provided a latch for holding closed a gate (or door) wherein the latch is adapted to co-operate with a striker arm, the latch comprising:
The housing may mount a lock having key actuation to displace the locking element in a rotary sense. The lock may be a cylinder lock with the locking element being in the form of a rotor, which may be rotatable through about 20° between its locking position and its displaced position.
The rotor may have first and second radially extending projections, the rearward of the projections having a side free for engaging the interference portion of the latching element, the side face being in a radial plane displaced around the axis of the rotor compared with a central radial plane around which the forward of the projections extends, an aperture being defined between the projections for accommodating a projecting tab of the latching element, whereby in the closed position of the latching element is retained by the projecting tab in the aperture.
The latch may be used with a remote actuator unit adapted to be mounted on the opposite side of the door or gate to the latch. The latch may incorporate the lock which can directly drive the locking element and the remote actuator may also have a key-operated lock so that either lock may unlock the latch.
Alternatively either the latch or remote actuator may have a key-operated lock and the other may have a manually actuated device for releasing the latch so that the door or gate can be opened. The manual actuator may be a button or emergency exit type crash bar.
The latching element can be biased suitably. One embodiment is upward biasing by a spring but magnetic, gravity or other biasing may be used. The locking element could be an arranged above or below the location at which in use the striker bar will present itself to the latching element.
Embodiments of the invention lend themselves to being used with a cylinder lock and the locking element being in the form of a rotor which is rotatable and mounted coaxially with the axis of the cylinder lock.
The latching element can be plate-like and can be substantially wholly enclosed for pivotal movement about a horizontal axis within the housing, a spring being provided for biasing the latching element towards the open position. However the latching element need not be pivotal or arranged as in this embodiment. For example the latching element may be of the nature of a sliding plate in a guide with a profiled exposed portion to function as a cam surface when engaged by the striker arm for displacement of the latching element during latching and self locking engagement.
Embodiments of the invention lend themselves to co operation with an optional rear actuator unit adapted to be mounted on the opposite side of a gate post to that of the latch. For this purpose the locking element is structured so that it can move relative to a base portion of the housing and the base portion of the housing is adapted to receive therethrough an actuating element associated with the rear actuator unit for operating the mechanism and in particular moving the locking element from the locking position and a displaced position. This may be achieved by providing a rotatable lock, such as a cylinder lock, in the rear unit and which drives a coupling bar which is in engagement with the locking element to rotate it from the locking position to the displaced position.
Where an egress mechanism is required in the rear operating unit, it may be in the form of a depressible actuator, for example in the form of a button or the like which moves in a guide towards the associated gate post, its motion being translated through a mechanical arrangement to provide rotary drive to move the latching element so that unlocking is achieved and the gate may be opened. For example a rack and pinion or worm and nut or similar mechanism may be used.
The embodiments illustrated are for normal operation of a key-operated lock. However, other embodiments may be configured by having remote electrical operation of either lock.
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
An embodiment of the invention will now be described with reference to the accompanying drawings, of which:
Referring first to the exploded view of
The base 22 is generally L shaped in plan view and has a side leg 36 adapted to be engaged over the face of a structure such as a gate post and secured to the gate post by screws 38. A main leg 39 of the base is symmetrical with two vertically spaced apertures 40A and 40B and this leg is also adapted to be secured to the gate post by upper and lower screws 42. The shell 24, when the components are assembled inside, is fitted to the base by a series of four screws 44 from the rear of the base into the shell 24 with a manually operated actuator, in this embodiment in the form of a cylinder lock 46 of the cartridge engaged in a corresponding aperture 48 in the shell and a rear barrel portion 50 of the cartridge engaged in the lower aperture 40A.
So that the gate latch can be fitted to either left hand or right hand opening gates, the unit can be reassembled with the base 22 rotated through 180° so that the opening 40B is lower and adapted to be engaged by the barrel 50.
The striker pin unit of
For this purpose, the tongue 28 has a projecting tab in the form of a protruding leg 84 (see
An aperture 85 is defined between the projections 82 and 83 for accommodating the projecting tab of the latching element, whereby in the latching position of the latching element the projecting tab is retained in the aperture.
More detail of assembly is shown in
Referring now to
In this embodiment the cap 100 is either not axially displaceable or, if axially displaceable, it is so by virtue of the bar 104 not fully penetrating the cavity in the rotor. In either event, any movement of the button if possible does not cause any function whatsoever but the structure described above has useful design criteria so that the unit may be useable in a second embodiment or, at least, many components of
In summary, the embodiment described above lends itself to efficient robust construction with relative simplicity in terms of the number of components and assembly. Furthermore, an important aspect is ease of fitting with hand tools and handheld drills to gates and gate posts. A single aperture is all that is needed to extend between the rear wall and front wall of a gate post in order to mount the optional rear access unit to engage with and align with the front latch assembly. By contrast, if drillings are required at spaced parallel locations there is a great difficulty in achieving on site precision with hand tools.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2006900451 | Jan 2006 | AU | national |
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| Number | Date | Country |
|---|---|---|
| 2405347 | Jun 1979 | FR |
| Number | Date | Country | |
|---|---|---|---|
| 20070175250 A1 | Aug 2007 | US |
