FIRE DOOR LOCK WITH LATCH BOLT IMMOBILISER

Abstract

 Fire door lock with a latch bolt immobilizer, of the type which is provided with a lock housing (9) having a central axis of symmetry (14) and equidistant insertion openings for lock cylinders (12) above and below the central axis (14) for use in doors that open on the right or on the left, and a latch bolt (5) which projects beyond the front of the lock (10) at the level of a central axis. The lock incorporates a lever (6) which is connected to the rocker (7) and the guard (8) and is able to move horizontally and in tandem into its immobilizing position when the cam (13) on the lock cylinder (12) is actuated, preventing contact between the actuating end (2a) of the follower (2) and the actuating lug (7a) of the rocker (7) during its rotational movement.

Description

Field of the invention

[0001] This invention relates to a fire door lock with latch bolt immobilizer, of the type which is provided with a lock housing having a central axis of symmetry and equidistant insertion openings for lock cylinders above and below the central axis for use in doors that open on the right or on the left, and a latch bolt which projects beyond the front of the lock at the level of a central axis.

Background art

[0002] Currently and referring to the state of the art, the use of a central latch bolt having two followers and cylinders symmetrically arranged in the central axis of the lock is usual and known in the fire door locks. In addition to the latch bolt, there are models that incorporate a lever pulled through a cam in the lock cylinder. Such models of fire door locks are commercially available and they offer two types of solutions having the following disadvantages. Firstly, the immobilization of the turn in the follower activating the withdrawal of the latch bolt is usual in the current fire door locks. Such immobilization of the follower may cause damages in the inner mechanisms of the lock if an excessive torque is applied to the lock. Secondly, nowadays it may be possible to withdraw the latch bolt acting in the handle or through handling for a fraudulent opening, even having the lever in a projected state. Such action consisting of the withdrawal of the latch bolt causes the removal of the door from the frame where said latch bolt was accommodated, in spite of having the lever in a projected state, since such levers have excessively big clearances regarding the frame and, therefore, the intumescent joints do not perform their function correctly any more in case of fire.

[0003] For example, the patent EP 2584124 shows a reversible lock having a lock housing and a latch projecting at the level of the central axis, having openings to accommodate the lock cylinder in both sides of the axis. Additionally, it comprises a bolt that may rotate two turns and it may be immobilized through a rib where a bit is engaged.

[0004] The patent EP 2484851 describes a mortise lock for use in doors that open on the right or on the left comprising at least a movable latch, at least a movable bolt, a first and a second movable rod in transversally opposing directions to the movement direction of the bolt and the latch, between an unblocking position of the door, wherein the first and the second rod are withdrawn towards the inner part of the carcass, and an immobilizing position of the door, wherein it extends towards the outer part of the carcass.

Explanation of the invention and advantages

[0005] In view of the above mentioned, this invention relates to a fire door lock with a latch bolt immobilizer which incorporates a lever which is connected to the rocker and the guard and is able to move horizontally and in tandem into its immobilizing position when the cam on the lock cylinder is actuated, preventing the contact between the actuating end of the follower and the actuating lug of the rocker during its rotational movement.

[0006] It is significant that the lever is able to deactivate the withdrawal mechanism of the latch bolt through the interaction between the follower and the rocker both having blocking projections and lacking them.

[0007] Thanks to this configuration, by moving the lever to the immobilizing position, the follower turns in the void and it is unable to withdraw the latch bolt since there is no contact between the actuating end of the follower and the actuating lug of the rocker. Thus, a possible damage in any part of the inner mechanism of the lock is avoided when an excessive torque is applied in the handle, or the withdrawal of the latch bolt and a subsequent removal thereof in the housing of the frame, causing the consequent loss of pressure of the intumescent joints that guarantee the isolation from fire.

[0008] Another feature of this invention is that the lever comprises an immobilizing face being able to connect to the immobilizing active area of the latch bolt preventing the withdrawal of said latch bolt when it is in the immobilizing position.

[0009] Thanks to the configuration of the lever, the latch bolt cannot be withdrawn from its position preventing thereby the violent forced movement by a card or like. By acting over the cylinder of the lock, the cam moves the guard and the lever as a whole horizontally from the resting position, where the latch bolt can be withdrawn when it acts over the follower, to the immobilizing position where the immobilizing face of the lever contacts the active area of the latch bolt exerting a limit and preventing the removal thereof.

[0010] It is relevant to point out that the lever admits different executions, and it may include immobilizing protrusions projecting from the door frame once the immobilizing position has been activated, or without them, both configurations being able to deactivate the interaction between the follower and rocker and to immobilize the latch bolt.

Drawings and references

[0011] For a better understanding of the nature of this invention a merely illustrative, non-limiting industrial embodiment is depicted in the appended drawings.

Figure 1 shows an isometric view of the fire door lock (1) having the latch bolt (5) and the lever (6) in the resting position.

Figure 2 shows an isometric view of the fire door lock (1) having the lever (6) in the resting position and the latch bolt (5) withdrawn after actuating over the follower (2) in the opening of the door.

Figure 3 shows an isometric view of the fire door lock (1) having a lever (6) projected towards the immobilizing position and the latch bolt (5) being immobilized.

Figure 4 shows an isometric view of the fire door lock (1) having a lever (6) projected in the immobilizing position and the latch bolt (5) being immobilized, wherein it is also seen that the opening through the follower (2) is disabled.

Figure 5a shows an isometric view of the lever (6) with the immobilizing face (6a), which has immobilizing protrusions (6b).

Figure 5b shows an isometric view of the lever (6) with the immobilizing face (6a) but without immobilizing protrusions (6b).

Figure 6 shows an isometric view of the latch bolt (5).

Figure 7 shows an isometric view of the guard (8).

Figure 8 shows an isometric view of the rocker (7)

Figure 9 shows an isometric view of the actuating arm of the latch bolt (5).

Figure 10 shows an isometric view of the follower (2).

1. - Fire door lock

2. - Follower

2a- Actuating end

3. - Recovering spring of the follower (2).

4. - Actuating arm of the latch bolt (5).

4a. - Actuating lug

4b. - Actuating end of the latch bolt (5).

5. - Latch bolt

5a. - Casting in "U"

5b. - Immobilizing active area

6. - Lever

6a. - Immobilizing face

6b. - Immobilizing protrusions

6c. - Lowering part

6d. - Central groove

7. - Rocker

7a. - Actuating lug

8. - Guard

8a. - Protrusion of guard (8)

9. - Lock housing

10. - Front of the lock

11. - Recovering spring of the latch bolt (5).

12. - Lock cylinder

13. - Cam

14. - Central axis

Statement of a preferred embodiment

[0012] Referring to the drawings and references listed hereinbefore, a preferred mode to carry out the object of the invention is illustrated in the appended planes, referred to a fire door lock having a lever (6) which is connected to the rocker (7) and the guard (8) and is able to move horizontally and in tandem into its immobilizing position when the cam (13) on the lock cylinder (12) is actuated, preventing contact between the actuating end (2a) of the follower (2) and the actuating lug (7a) of the rocker (7) during its rotational movement.

[0013] As it is seen in figures 1 and 2, when the lock is in the resting position, by acting over the follower (2) the actuating end (2a) contacts the actuating lug (7a) of the rocker (7) moving it vertically. During the movement, the actuating lug (7a) of the rocker (7) acts against the lug (4a) of the actuating arm of the latch bolt (5), which moves the latch bolt (5) horizontally by acting the actuating end (4b) in the casting in "U" of the latch bolt (5).

[0014] Figure 3 and 4 show, by acting over the lock cylinder (12), how the cam (13) moves the lever (6) horizontally to the immobilizing position. In said position, the rocker (7) and the guard (8), being connected to the lever (6), are moved horizontally and in tandem, preventing contact between the actuating end (2a) of the follower (2) and the actuating lug (7a) of the rocker (7) during its rotational movement.

[0015] In this position it is seen that the actuating arm (2a) cannot interact with the actuating lug (7a) of the rocker (7) preventing the withdrawal of the latch bolt (5). Thus, a possible damage in any part of the inner mechanism of the lock is avoided when an excessive torque is applied in the handle, or the withdrawal of the latch bolt (5) causing a removal of said latch bolt (5) in the housing of the frame and the consequent loss of pressure of the intumescent joint that guarantee the isolation from fire.

[0016] As it is seen in figures 3 and 4, another feature of this invention is that, by acting over the lock cylinder (12) the cam (13) moves the lever (6) horizontally and the immobilizing face (6a) contacts to the immobilizing active area (5b) of the latch bolt (5) and immobilizes it and prevents it from withdrawal.

[0017] This latch bolt (5) immobilization guarantees the absence of latch bolt (5) withdrawal in an attempt of fraudulent opening when the lever (6) is in the immobilizing position.

[0018] As it is seen in figures 5a and 5b, another features of the invention is that the lever (6) admits two different executions, with or without immobilizing protrusions (6b).

Claims

1. Fire door lock with a latch bolt immobilizer, of the type provided with a lock housing (9) having a central axis of symmetry (14) and equidistant insertion openings for lock cylinders (12) above and below the central axis (14) for use in doors that open on the right or on the left, and a latch bolt (5) which projects beyond the front of the lock (10) at the level of a central axis, characterized by the incorporation of a lever (6) which is connected to the rocker (7) and the guard (8) and is able to move horizontally and in tandem into its immobilizing position when the cam (13) on the lock cylinder (12) is actuated, preventing contact between the actuating end (2a) of the follower (2) and the actuating lug (7a) of the rocker (7) during its rotational movement.

2. Fire door lock with a latch bolt immobilizer, according to claim 1, characterized by the lever (6) comprising an immobilizing face (6a) able to connect to the immobilizing active area (5b) of the latch bolt (5) preventing the withdrawal of said latch bolt (5) when it is in the immobilizing position.

Drawing