GB1593399A - Latches - Google Patents

Description

(54) IMPROVEMENTS RELATING TO LATCHES (71) We, DOVER ROLLER SHUTTERS LIMITED, a British Company of Wheaton Road, Witham, Essex, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to a latch which engages automatically when a closure member, such as a shutter or door, is closed so as to hold the member in closed position and which can be released by a manual operation to enable the member to be opened.

An object of the invention is to provide an improved latch mechanism for a shutter and which is of small dimensions so that it can readily be mounted in the bottom rail of the shutter.

According to the present invention the improved latch mechanism comprises a housing adapted for mounting in the bottom rail of the shutter, two slide bars mounted side by side in the housing for endwise movement therein and each having a free end which projects from a respective end of the housing, each slide bar having in that side which faces the other slide bar a recess one side of which provides a surface arranged at an angle to the direction of movement of the bar, spring means biassing the free end of each slide bar outwardly of the housing, and a manually operable plunger mounted for movement at right angles to the direction of movement of the slide bars, the plunger having two oppositely angled surfaces positioned for engaging each with a respective angled surface of the recesses in the slide bars, the arrangement being such that movement of the plunger towards the housing causes the free ends of the slide bars to be retracted towards the housing.

The two angled surfaces may be angled at 45" to the direction of movement of the slide bar and to the direction of movement of the plunger.

The present invention also comprises a shutter having mounted in the bottom rail thereof a latch mechanism as above described and wherein the free end of each slide bar is connected with one end of a bolt, the other end of which extends beyond a respective end of the bottom rail for engagement with a fixed latch plate.

A latch mechanism according to the invention will now be described with reference to the accompanying drawing which illustrates the use of the mechanism as a latch for a shutter. In the drawing: Figure 1 is a sectional plan view taken on the line I-I of Figure 2, and Figure 2 is a sectional side view taken on the line II-II in Figure 1.

Referring now to the drawing the latch shown has a bolt 1, which as shown is straight but may be cranked, and a second bolt, not shown, which is similar to the bolt 1 but oppositely directed, both of which are retracted by means of a plunger 2.

The plunger is mounted in a handle 3 which is attached to the bottom rail 4 of a shutter.

The inner end of the plunger has an angled surface 5a for retracting the bolt 1 and a second angled surface 5b, for retracting the second bolt. The angled surfaces 5a and 5b cooperate respectively with angled surfaces 6a and 6b provided at one side of recesses 7a and 7b formed in slide bars 8a and 8b. These slide bars are accommodated, one on top of the other, in a housing 9 attached inside the botttom rail 4.

The ends of the slide bars are connected with respective bolts in the manner illustrated as regards the slide bar 8a. As shown the outer end of the slide bar 8a is housed in a sleeve 10 wherein it is pinned. The inner end of the bolt 1 is also pinned into the sleeve 10 which thereby connects the slide bar 8a to the bolt 1. A spring 11 acting between the housing 9 and the sleeve 10 biasses the bolt and the slide bar outwardly of the shutter. The outer end of bolt 1 is guided by an aperture 12 in the bottom rail 4.

In operation, the shutter to which the latch is fitted can be opened by depressing the plunger 2. The surfaces 5a and 5b then slide along the corresponding surfaces on the slide bars 8a 8b. This causes the slide bars and thus the bolts to be drawn in against the action of the springs and the bolts to withdraw from latch plates 13. The shutter can now be opened.

In closing the shutter it need merely be pushed towards its closed position whereupon the bolts engage with inclined surfaces 14 on the latch plates and are thereby pushed in. When the shutter reaches the closed position the bolts will shoot out under the latch plates.

The arrangement of this invention may incorporate a lock. In one form the lock would operate to prevent the plunger being depressed and would conveniently be of the kind which retains its key except when this key has been turned to the locked position. The lock cylinder may be accommodated in the plunger 2.

WHAT WE CLAIM IS: 1. A latch mechansim for a shutter comprising a housing adapted for mounting in the bottom rail of the shutter, two slide bars mounted side by side in the housing for endwise movement therein and each having a free end which projects from a respective end of the housing, each slide bar having in that side which faces the other slide bar a recess one side of which provides a surface arranged at an angle to the direction of movement of the bar, spring means biassing the free end of each slide bar outwardly of the housing, and a manually operable plunger mounted for movement at right angles to the direction of movement of the slide bars, the plunger having two oppositely angled surfaces positioned for engaging each with a respective angled surface of the recesses in the slide bars, the arrangement being such that movement of the plunger towards the housing causes the free ends of the slide bars to be retracted towards the housing.

2. A latch mechanism as claimed in claim 1 wherein the angled surfaces on the slide bars are angled at 450 to the direction of movement of the slide bars and the direction of movement of the plunger.

3. A latch mechanism as claimed in either preceding claim including a lock for locking the plunger.

4. A latch mechanism as claimed in claim 3 wherein the lock is of the kind which retains its key except when the key has been turned to the locked position.

5. A latch mechanism as claimed in claim 1 and substantially as hereinbefore described with reference to the accompanying drawing.

6. A shutter having mounted in the bottom rail thereof a latch mechanism as claimed in any preceding claim and wherein the free end of each slide bar is connected with one end of a bolt, the other end of which extends beyond a respective end of the bottom rail for engagement with a fixed latch plate.

7. A shutter as claimed in claim 6 and substantially as herein described with reference to the accompanying drawing.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (7)

**WARNING** start of CLMS field may overlap end of DESC **. the sleeve 10 biasses the bolt and the slide bar outwardly of the shutter. The outer end of bolt 1 is guided by an aperture 12 in the bottom rail 4. In operation, the shutter to which the latch is fitted can be opened by depressing the plunger 2. The surfaces 5a and 5b then slide along the corresponding surfaces on the slide bars 8a 8b. This causes the slide bars and thus the bolts to be drawn in against the action of the springs and the bolts to withdraw from latch plates 13. The shutter can now be opened. In closing the shutter it need merely be pushed towards its closed position whereupon the bolts engage with inclined surfaces 14 on the latch plates and are thereby pushed in. When the shutter reaches the closed position the bolts will shoot out under the latch plates. The arrangement of this invention may incorporate a lock. In one form the lock would operate to prevent the plunger being depressed and would conveniently be of the kind which retains its key except when this key has been turned to the locked position. The lock cylinder may be accommodated in the plunger 2. WHAT WE CLAIM IS:

1. A latch mechansim for a shutter comprising a housing adapted for mounting in the bottom rail of the shutter, two slide bars mounted side by side in the housing for endwise movement therein and each having a free end which projects from a respective end of the housing, each slide bar having in that side which faces the other slide bar a recess one side of which provides a surface arranged at an angle to the direction of movement of the bar, spring means biassing the free end of each slide bar outwardly of the housing, and a manually operable plunger mounted for movement at right angles to the direction of movement of the slide bars, the plunger having two oppositely angled surfaces positioned for engaging each with a respective angled surface of the recesses in the slide bars, the arrangement being such that movement of the plunger towards the housing causes the free ends of the slide bars to be retracted towards the housing.

2. A latch mechanism as claimed in claim 1 wherein the angled surfaces on the slide bars are angled at 450 to the direction of movement of the slide bars and the direction of movement of the plunger.

3. A latch mechanism as claimed in either preceding claim including a lock for locking the plunger.

4. A latch mechanism as claimed in claim 3 wherein the lock is of the kind which retains its key except when the key has been turned to the locked position.

5. A latch mechanism as claimed in claim 1 and substantially as hereinbefore described with reference to the accompanying drawing.

6. A shutter having mounted in the bottom rail thereof a latch mechanism as claimed in any preceding claim and wherein the free end of each slide bar is connected with one end of a bolt, the other end of which extends beyond a respective end of the bottom rail for engagement with a fixed latch plate.

7. A shutter as claimed in claim 6 and substantially as herein described with reference to the accompanying drawing.