GB2283277A - Slam lock - Google Patents

Abstract

A locking mechanism comprises a pair of locking jaws (17) adapted to receive a locking bar (6) figs 1, 2 (not shown). The jaws are retained in a housing on a door frame whereas the locking bar is mounted on a door. In a locked configuration the locking bar is retained by the jaws and can only be released by manual operation to effect movement of the bar along its longitudinal axis. In a released configuration the jaws are separated by a cam (27) to permit the locking bar to move in a direction perpendicular to its longitudinal axis and out of the housing through an entry slot. The cam may be rotated by a pinion 24 rotated by a sliding rack 23 operated by a motor or solenoid. <IMAGE>

Description

A LOCK MECHANISM This invention relates to a lock mechanism particularly but not exclusively for application to retractable and canopy doors.

Retractable and canopy doors are used in industrial and domestic environments. The doors are operable between a vertical closed position and an open position in which the door is disposed above the door opening.

Presently such doors are generally locked in the closed position by one of two mechanisms; a slam latch or a solid locking bar assembly. A slam latch comprises a protruding locking tongue which is attached to the door and is engageable in a receptacle with a sloping leading edge disposed on the door frame cross member. The tongue is coupled to the door handle by means of a linkage. When the door is closed the tongue is depressed by the sloping edge until the door is completely shut whereupon the tongue latches into the receptacle behind the sloping edge. To release the latch the door handle is rotated to retract the tongue free of the receptacle, allowing the door to be opened.

A locking bar assembly comprises a solid bar which is fixed vertically to the inside face of the door. The assembly has a linkage mechanism by which a handle on the outside of the door can be turned to move the bar axially in the vertical direction. The door frame has an aperture designed to receive the end of the locking bar. In order to lock the door in the closed position the handle is turned in a first direction to move the locking bar vertically such that it is received in the aperture. The door is opened by turning the handle in the opposite direction to withdraw the end of the bar from the aperture.

It is an object of the present invention to provide a slam latch mechanism with improved security.

According to the present invention there is provided a locking mechanism comprising at least one retaining member adapted to receive a locking member, wherein in a released configuration the locking member is movable relative to said at least one retaining member in first and second directions to release the locking member from the at least one retaining member, and in a locked configuration the locking member is prevented from moving in said first direction by said at least retaining member.

Preferably a pair of retaining members are provided which are movable together into the locked configuration and apart into the released configuration. One or both of the retaining members may be resiliently biased towards said locked configuration.

Each retaining member defines a recess, the recesses combining in the locked configuration so as to form a substantially encircled area in which said locking member is retained against movement in said first direction but which area permits movement of the locking bar in said second direction.

The retaining members may be movable apart by a cam which is rotatable about an axis by an actuator which is preferably an automatically operable rack and pinion.

At least one retaining member conveniently has a cavity in which the cam is received and the or each cavity may have a sloping surface against which the cam bears during rotation to separate the retaining members. In order to effect separation of the retaining members the cam may have at least one radially outward protrusion which bears against at least the or each sloping surface during rotation.

In a preferred embodiment the locking member is a round bar and movement in said first direction corresponds to axial movement of the bar, which movement may be effected through a manually operable mechanical linkage.

The locking mechanism may be mounted on a barrier and frame assembly, the barrier being lockable to the frame by means of a locking mechanism.

A specific embodiment of the present invention will now be described with reference to the accompanying drawings in which: Fig. 1 is a perspective view of a canopy door with a locking mechanism according to the present invention; Fig. 2 shows a plan view of a locking mechanism according to the present invention in the locked configuration; Fig. 3 shows a plan view of the locking mechanism of Fig. 2 in the unlocked configuration; Fig. 4 shows a cross-sectioned view along line X-X of Fig. 2; Fig. 5 shows a cross-sectioned view along line Y-Y of Fig. 3; and Fig. 6 shows a plan view of a second embodiment of locking mechanism according to the present invention in the locked configuration.

Referring to the Fig. 1 there is shown a conventional canopy door arrangement with a locking arrangement (indicated generally by arrow 4) of the present invention fitted. A door 1 is pivotable relative to the frame 2 and also movable vertically along a track 3 to enable it to move from the vertically disposed closed position to an open position in which is disposed horizontally above the door opening. The locking arrangement 4 comprises a housing 5 arranged to receive a vertically disposed locking bar 6 fixed to the door 1. The housing 5 is fitted to an upper cross member of the door frame 2.

The mechanism, shown in detail in Figs. 2 and 3 is fitted inside the housing 5 which comprises side walls 7, a front wall 8 with a vertical slot 9, a base plate 10 with a horizontal slot 11 which is open to the slot 9 on the front wall 8, a rear wall 12 with outwardly extending attachment flanges 13 and an internal wall 14 which separates locking jaws 15 from an actuating device 16.

The locking jaws 15 are of hooked configuration and each has an arcuate recess 17 adjacent to which is an angled entry face 18. The arcuate recesses 17 face each other and are disposed substantially above the closed end of the horizontal slot 11. The angled entry faces 18 are inwardly directed from the front wall 8 towards the arcuate recesses 17. At the end of each jaw 15 opposite the angled entry face 18 there are cut-out recesses 19, 20. The recesses 19, 20 are vertically displaced; one being above the other.

The locking jaws 15 each have a boss 21 which faces the interior of the housing side walls 7. One end of a compression spring 22 is located on each boss 21, the other end being received in a circular indent (not shown) in the housing side wall 7.

The actuating device 16 which is located between the rear wall 12 and the internal wall 14 comprises a rack 23 and pinion 24. The rack extends through apertures (not shown) in the side walls 7 and has holes 25 at each end to which a drive (not shown) is connected, for example, a motor or a solenoid. The pinion wheel 24 is rotatably mounted on a shaft 26 which bridges the rear and internal walls 12, 14 and extends beyond the internal wall 14 where it is fixedly connected to a cam 27. Movement of the rack 23 from side to side within the housing by the drive causes the pinion wheel 24 and thus cam 27 to rotate.

The cam 27 is disc shaped with two diametrically opposed quartiles having axially raised surfaces in the form of turrets 28.

Figures 2 and 4 show the mechanism in the locked configuration. The locking jaws 15 are forced together by their respective compression springs 22 such that the hooked ends 1 spa of the jaws overlap. In this configuration the cam 27 is oriented with the turrets 28 disposed so that they re received wholly within the cut-out recesses 19, 20. When the door 1 is closed the locking bar 6 enters the front slot 9 of the housing and bears against the angled entry faces 18 of the locking jaws 15. Further movement of the locking bar 6 into the housing along the slot 11 in the bottom plate 11 causes the jaws 15 to be forced apart against the bias of the compression springs 22.When the locking bar 6 reaches the closed end of the bottom slot 11 it is at a position beyond the angled faces 18 of the locking jaws 15 and the jaws 15 close around the bar 6 such that it is held in the arcuate recesses 17 of the locking jaws 15. The door 1 is now locked to the door frame 2.

The door may be unlocked mechanically or electrically. In the mechanical operation the locking bar 6 is removed from the jaws 15 by moving it vertically relative to the housing such that the end of the bar 6 is free of the housing. This is achieved in a conventional manner by rotating a handle (not shown) on the outside of the door 1 which actuates a linkage (not shown) to cause the locking bar movement.

In order to unlock the door automatically the motor or solenoid which is connected to the rack 23 by way of a linkage (not shown) is operated to push or pull the rack 23 sideways (to the right in Fig. 2) relative to the housing. The lateral movement of the rack 23 causes the pinion wheel 24 and thus cam 27 to rotate. The cam 27 is rotated through one-quarter turn (anti-clockwise in Fig. 4) and the turrets 28 emerge from their respective recesses 19, 20 to bear against the opposite jaw 15. As the cam 27 rotates through 90" the turrets force the jaws 15 to move apart against the force of the compression springs 22. This configuration is shown in Figs. 3 and 5. With the jaws 15 apart the locking bar 6 is free to move along the bottom slot 11 and out of the locking mechanism housing 5 through the front slot 9 in order to open the door 1.When the locking bar 6 is free the electrical drive is turned off and the spring force is such that the cam 27 is forced to rotate one-quarter turn to the rest position shown in Fig. 4 and the jaws 15 close together.

A second embodiment of lock mechanism is shown in Fig. 6. This mechanism is generally the same as the mechanism of the first embodiment save that only one locking jaw 15 is utilised, and the locking bar 6 is retained in the arcuate recess of the single jaw by a side wall 31 of the lock housing.

Of course, the second embodiment may include any one or more of the features of the first embodiment.

The above described locking mechanism combines the simplicity of a slam latch with the security of a locking bar arrangement and has the advantage that it can be operated both manually by mechanical means and automatically by electrical means.

It is of course to be understood that the invention is not intended to be restricted to the details of the above embodiment which are described by way of example only.

Claims (15)

1. A locking mechanism comprising at least one retaining member adapted to receive a locking member, wherein in a released configuration the locking member is movable relative to said at least one retaining member in first and second directions to release the locking member from the at least one retaining member, and in a lock configuration the locking member is prevented from moving in said first direction by said at least one retaining member.

2. A locking mechanism according to claim 1, wherein the at least one retaining member is resiliently biased towards said locked configuration.

3. A locking mechanism according to claim 1 or 2 in which there is provided a pair of retaining members which are movable together into the locked configuration and apart into the released configuration.

4. A locking mechanism according to claim 3, wherein the retaining members each define a recess, the recesses combining in the locked configuration so as to form a substantially encircled area in which said locking member is retained against movement in said first direction but which area permits movement of the locking bar in said second direction.

5. A locking mechanism according to claim 3 or 4, wherein the retaining members are movable apart by a cam which is rotatable about an axis by an actuator.

6. A locking mechanism according to claim 5, wherein the actuator is a rack and pinion arrangement which is remotely operable.

7. A locking mechanism according to claim 5 or 6, wherein at least one retaining member has a cavity in which the cam is received.

8. A locking mechanism according to claim 7, in which the cam has at least one axial protrusion which, when in the locked configuration, resides in the at least one cavity.

9. A locking mechanism according to claim 8, wherein the cam has at least one axial protrusion which bears against at least the or each jaw during rotation in order to separate the retaining members.

10. A locking mechanism according to any preceding claim, wherein the locking member is a round bar and movement in said first direction corresponds to axial movement of the bar.

11. A locking mechanism according to claim 10, wherein axial movement of the bar is effected through a mechanical linkage which is manually operable.

12. A locking mechanism according to any one of claims 2 to 11, in which the retaining members are located in a housing having an entry slot which the locking member enters to engage the retaining members.

13. A locking mechanism according to claim 12, wherein the retaining members each have an angled surface adjacent the entry slot, the surfaces being designed to enable the locking member to move the retaining members apart after it enters the entry slot.

14. A barrier and frame assembly incorporating a locking mechanism according to any one of claims 1 to 13.

15. A locking- mechanism substantially as hereinbefore described with reference to the accompanying drawings.