SE505779C2 - Locking mechanism - Google Patents

Abstract

A lock mechanism includes a lock bolt mechanism (6), for instance a key actuated mechanism, having a lock bolt (20a) and a latch bolt mechanism (4) including a latch bolt (9) and actuated by a follower lever (17). Movement of the lock bolt (20a) between its terminal positions is generated and stepped-up, or geared, through the medium of a connecting rod (24) and a transmission lever (22). The mechanism also includes a locking lever (32) and a coupling lever (27) and a dogging lever (31) by means of which the follower lever (17) of the latch mechanism (4) can be actuated to retract the latch bolt (9), for instance by turning a key. The lock mechanism is constructed in accordance with a module system for adaptation to different backsets and centre distances, cylinder/knob. The lock mechanism is adapted to suit differing backsets by using one or more connecting rods (24) having one or more alternative points (24a) of pivotal attachment to the transmission arm. The remainder of the lock bolt mechanism remains essentially unchanged when making such adjustments, possibly with the exception of the coupling lever (27). With regard to the latch bolt mechanism, a press rod (10) having a length commensurate with a relevant backset is exchangeably mounted in position while the remainder of the latch mechanism (4) remains essentially unchanged. Quick-release levers (39) of different lengths commensurate with different cylinder-knob centre-to-centre distances can be exchangeably mounted on a pivot shaft (38) in the region of the edge of the lock housing distal from the latch and lock bolts.

Description

505 779 2 According to the standard in force in other countries, a two-turn key rotation is required for a full piston stroke. It is then possible to achieve "half locking", ie to remove the key after only one turn, while "locking for the night" by turning the key two turns.

Other problems are related to the fact that locks that are used for different purposes and in different contexts must necessarily have different mandrel depths and center distances between the pressure and the core of the cylinder lock. Different countries also have different standards for such mandrel depths and c-c distances and it is realized that adaptation to current standard dimensions often requires redesign of vital parts to the lock, especially if at the same time e.g. wants to set up the rule mechanism for full rule deflection in the case of one-turn rotation.

The adaptation work to various applicable standards is also complicated by the fact that in lock constructions of the type in question, there are often other special requirements and wishes, e.g. that after locking the locking mechanism with the cylinder lock key, it must be possible to lock the down piston by continuing to turn the key.

It also occurs, e.g. in the case of locks for public premises such as cinemas and the like, that there are requirements for evacuation security, which means that a locking mechanism, the rule mechanism of which is locked from the outside, e.g. in a panic situation, it must be possible to open it with a simple pressure movement from the inside.

This requires a different type of connecting element between the fall mechanism and the rule mechanism. Adaptation to varying standards of mandrel depths and c-c distances in accordance with the above entails difficulties with regard to the design of the locking mechanisms so that the specified special functions can be performed.

State of the art In an article in "The National Locksmith", May 1993, p. 23-27 describes "Schlage Mortise Locks" which indicate a number of characteristics and a number of tests performed on a lock of the type in question. Among other things, the possibility of changing the locking side of the locking unit without disassembly is mentioned. The change can thus take place by moving a screw from one side of the lock housing to the other.

The lock construction is comparatively complicated with a number of components. The article does not make a proposal to easily adapt this locking construction to changed or standardized mandrel depths resp. c-c-distance pressure-cylinder lock and it will be appreciated that the compact design of the locking mechanism would require a thorough redesign of the mechanism as a whole in, for example, a reduction of the mandrel depth.

The locking constructions described in e.g. DE, Al, 34 00 618 (Karrenberg), DE, C2,30 37 018 (Fliether) and EP, Al, 0 535 497 (CISA), the latter of which specifically describes a locking mechanism of the type in question with evacuation function, also does not propose any constructive measure to facilitate adaptation to changing mandrel depths and / or cc-distance pressure cylinder.

Further examples of the state of the art can be found in US, A, 4,516,798 (Bergen), US, A, 4,671,089 (Fleming et al) and DE, A1, 3,540,848 (Schindler).

OBJECTS OF THE INVENTION More particularly, the present invention relates to a lock with a locking mechanism of the type stated in the preamble of claim 1.

A basic idea behind the invention is to design a locking mechanism of this kind according to a modular thinking and more specifically in such a way that at different mandrel depths the main part of the components of the locking mechanism should be unchanged while a few components in the lock are easily interchangeable resp. adaptable to such occurring varying mandrel depths.

Within the basic idea of this invention, it must also be possible to meet one or more of the above-mentioned special requirements for a locking mechanism of the type specified, such as, for example, one-turn rotation of the key resp. functional adjustments for adaptation to various special present requirements resp. requirements, such as the impact piston impact by means of the key resp. evacuation safety through pressure piston impact via pressure, etc.

Correspondingly, an object of the invention is to provide a locking mechanism designed according to a modular system which enables easy adaptation to mandrel depth variation.

Another purpose is to offer, with one-turn operation of the cylinder lock, the possibility of maneuvering the fall function via the cylinder lock and - when desired or required - evacuation function through the possibility of retraction of the bolt by means of pressure.

A further object is to provide a locking mechanism of the type indicated, in which in a preferred embodiment it is ensured that the locking bolt is in its release position when the cylinder lock carrier means approaches the recess on the coupling rod with which it is to cooperate to carry the bolt to locked mode.

Brief description of the invention These and other objects are fulfilled by a locking mechanism according to the invention, the essential features of which are stated in the characterizing part of claim 1.

Because the coupling rod transmits movement from the cylinder lock drive means to the transfer arm which directly affects the bolt and causes gearing of the carrier means movement is required at different mandrel depths, as far as the control mechanism is concerned, only that the coupling rod is replaced or its active length changes which - in small mandrel depth changes only number, e.g. four possible articulation points for the transfer arm on the coupling rod.

An important feature of a locking mechanism according to the invention is thus the presence of a coupling rod actuated by the carrier means of the cylinder lock, which can be easily exchanged and / or offers alternative connection possibilities with cooperating elements so that exchange of the movement of the carrier means is allowed.

In the event of major changes in mandrel depth, replacement of the entire coupling rod is normally required, which is designed in a manner similar in principle and suitably also has several alternatively useful articulation points.

Claim 2 states an advantageous embodiment of a locking mechanism according to the invention in which a favorable gear ratio in the mechanism is obtained. The torque required for retracting the drop and control piston by means of key rotation is very small in the case of a parallelogram mechanism of the type indicated compared with known locking mechanisms.

The device defined in claim 3 ensures interlocking even if the coupling rod should end up in an intermediate position when moving in either direction.

In a locking mechanism according to the invention, it is preferred that the control mechanism is otherwise, possibly with the exception of the coupling arm, substantially unchanged. At greater mandrel depths, a coupling arm of greater length may thus be required.

For adapting the drop mechanism to different mandrel depths, it is preferred that a push rod with a length adapted to the current mandrel depth is interchangeably applicable between the pressure paddle and the pressure paddle arm, while the drop mechanism is otherwise substantially unchanged.

In the case of particularly large mandrel depths, a special guide can be introduced in the lock housing, since otherwise the distance between the piston rod of the falls and the rudder's storage element - where the piston's guide is normally located - would be too large.

In order to effect adaptation also to different center distances between the pressure of the falling mechanism and the cylindrical locking core of the locking mechanism, the locking mechanism is preferably designed as stated in claims 6 and 6, respectively. 7.

Further preferred embodiments of the invention are set out in the appended claims.

Some embodiments of the invention will be described below in more detail with reference to the accompanying drawings.

Brief description of the drawing figures Fig. 1 is a perspective view of a lock housing with pressure and cylinder lock, which lock housing occupies a locking mechanism according to the invention.

Fig. 2 is a plan view of the lock housing according to Fig. 1 with the lid removed. The lock housing with the associated locking mechanism is intended for an application case with a relatively small mandrel depth and often occurring center distance between the pressure and the shaft of the cylinder core.

The pistons for both cases and the locking mechanisms are in their locking or interlocking positions.

Fig. 3 is a view corresponding to Fig. 2 with the control piston in the retracted position by means of the cylinder lock key.

Fig. 4 is a view corresponding to Figs. 2 and 3 after continued key rotation, whereby the plunger is also moved to the release position.

Fig. 5 is a view corresponding to Figs. 2-4, in which after an initial position according to Fig. 2 the pressure of the drop mechanism is actuated so that the drop piston is moved to the release position and at the same time the evacuation arm actuates the control mechanism coupling rod so that the control piston is also moved to the release position.

Fig. 6 shows a view corresponding to Fig. 5 after the pressure of the falling mechanism has been released, whereby the falling piston has assumed the locking position. The position which then arises for the locking mechanisms corresponds to that shown in Fig. 2, where, however, a corresponding position is achieved by being moved from the initial position according to Fig. 1 to the control piston to the release position by means of the key. Fig. 7, finally, illustrates the locking mechanism according to the invention used in a locking housing for a substantially greater mandrel depth, both locking mechanisms being in the initial position corresponding to Fig. 1, i.e. with both pistons in the locking position.

Description of preferred embodiments Figs. 1-6 show a lock 1 according to the invention accommodated in a lock housing 2 with a locking post 3, in which lock housing 2 is accommodated a drop mechanism 4 for pressure action and a locking mechanism 6 actuated by a cylinder lock 5. The two locking mechanisms 4 and 6 are arranged for mutual interaction and designed according to a modular system to enable easy adaptation to varying mandrel depths and center distances between the pressure mechanism 8 of the drop mechanism and the shaft of the core 7 of the cylinder lock 5. The embodiment shown in Figs. 1-6 is intended for relatively small mandrel depth and "normal", ie frequent, cc-distance. The specified modular structure of the lock means that most of the components accommodated in the lock housing must have the same design and dimensions at varying mandrel depths and c-c distances. Only a few of the components need to be changed. For the coupling rod, which will be described in detail below, the same coupling rod can be used at four different mandrel depths, while in the event of further expansion of the mandrel depth, e.g. according to the embodiment shown in Fig. 7, needs to be replaced by another of basically similar design but with a greater length.

The drop mechanism 4 accommodated in the lock housing 2 comprises a bearing element 12 for a pressure rudder 13 with a square shaft 13e for a pressure 8. The pressure rudder 13 has a stop lug 13a for engaging against one end of a push rod 10 whose other end engages against a circumferential rod. a shaft 18 pivotable pressure rowing arm 17.

The upper end 17a of the pressure rowing arm engages between abutment lugs 11a, 11b on a piston rod 11, which at its one end receives a drop piston 9. The opposite end of the piston rod 11 is received in a guide 12a in the bearing element 12 of the rudder 13.

The rudder 13 performs pressure-swinging movement against the action of a spring 14 which is accommodated in a spring holder 15. 505 779 s The pressure rudder arm 17 is further actuated by a spring 19 which abuts partly against the pivot axis 18 of the pressure rudder arm 17 and partly against a portion 17b of the pressure rudder arm. Other placement of the spring or abutment directly against the stop lug 11a may also occur.

The pressure rudder 13 has a further stop lug 13b for actuating an evacuation arm 39 located in the rear edge of the lock housing 2 which is pivotable about a shaft 38 and arranged to allow retraction of the control mechanism by means of the pressure in a manner to be described in more detail below.

The locking mechanism 6 also accommodated in the lock housing 2 is arranged for actuating a cylinder lock 5. Other types of actuation from in- resp. the outside is possible.

In the embodiment shown, the latch mechanism consists of a latch 20 which is arranged for rectilinear movement by means of a guide groove 20c. The rule further has a rule piston 20a and two stop lugs 20b.

A coupling rod 24 is provided with a recess 24b for engaging a carrier member 7a associated with a core 7 of the cylinder lock 5 for moving the coupling rod 24 between two end positions.

A coupling rod 24 cooperates with the connecting rod 24, which is hingedly connected thereto, which is pivotable about a shaft 21 located at one end thereof. The transfer arm 22 has a portion 22a which engages between the stop lugs 20b of the bolt 20. In this way, transmission of the movements of the coupling rod 24 to the bolt 20 is permitted in a manner which allows exchange of the movements of the carrier means 7a. In this case, a full piston stroke can be achieved with only one revolution of turning the key of the cylinder lock 5 (not shown).

The connecting rod 24 shown has at its one end four holes 24a which are alternatively usable at different mandrel depths for connection to a central hinge pin 22c on the transfer arm 22. At greater mandrel depths than the one shown, the left of these holes 24a is used, while at smaller mandrel depth the right hole 24a 9 505 779 was used. At even greater mandrel depths, e.g. As shown in the embodiment of Fig. 7, the entire coupling rod 24 must be replaced with a designated 24 'of greater length and provided with an additional number of holes 24'a.

In addition, a locking arm 32 for the bolt 20 cooperates with the coupling rod 24, which locking arm 32 is pivotable about a pin 43 received in the groove 20c in the locking piston 20. The locking arm 32 is arranged to prevent it from being depressed in the locking position of the bolt 20. During the pivoting movement of the transfer arm 22 for locking the bolt 20, the interlocking arm 32 is actuated by a lug 22b on the inside of the transfer arm 22, the interlocking arm 32 being pivoted upwards around the pin 43 so that the locking movement of the bolt is allowed.

The coupling rod 24 also cooperates with a coupling arm 27 provided with a stop lug 27a, which at its one end is supported pivotably about a shaft 26. The coupling arm 27 is movable together with the coupling rod 24, so that during a locking movement of the bolt 20 moves to a position in which the stop lug 27a can be passed by the carrier means 7a of the cylinder lock.

When locking the bolt 20, the coupling arm 27 assumes the position shown in Fig. 3, in which the stop lug 27a, in the case of continued rotational movement of the carrier member 7a past the position in which complete locking has been achieved, is struck by the carrier member.

After abutment between the carrier means 7a and the abutment lug 27a of the coupling arm, according to Fig. 4, in the case of continued rotational movement, pivoting of the coupling arm 27 about its axis of rotation 26 is effected.

The locking mechanism also includes a carrier arm 31 which forms a transmission link with which the falling mechanism can be actuated by the locking mechanism for locking the piston. The carrier arm 31 is pivotable about a shaft 30 and has at one end a projection 3la arranged to be actuated by the coupling arm 27 during its pivoting movement under the action of the carrier member 7a. Upon such actuation, the carrier arm 31 is pivoted about its axis 30, a stop means 31l at the upper end of the carrier arm engages against the lower portion 17c of the pressure rudder arm 17, so that the pivot of the carrier arm 31 causes insertion of the drop piston 9 via the pressure rower arm 17.

The control mechanism also includes a control arm 34 which is pivotable about a shaft 33 at one end and which control arm 34 has at its other end a pivot pin 23 which is connected to the rear end of the coupling rod 24, the opposite arm 22 opposite. In this way, the coupling rod 24 forms part of a parallelogram link mechanism with the four articulation points 21, 22c, 33, 23. The coupling rod 24 will thereby perform a substantially rectilinear displacing movement when it acts on the carrier means 7a as in key rotation of the core 7 of the cylinder lock 5 engages in the recess 24b.

The control arm 34 also has the important task of ensuring that the coupling rod assumes its end position when the carrier means 7a is to engage the recess 24b in the coupling rod 24, namely in order thereby to prevent the coupling rod from assuming an intermediate position which makes such engagement impossible.

For this purpose, the control arm 34 has a projection 34a against which the carrier means 7a will engage in the event that the coupling rod should be in an intermediate position during the rotational movement of the carrier means. When the carrier member strikes the projection 34a on the control arm 34, it will pivot about its axis 33 so that the hinge shaft 23 connecting the control arm 34 and the coupling rod 24 moves to the right in the drawing figures and the coupling rod 24 assumes its end position, in which the control mechanism is completely locked and the carrier means 7a can engage in the recess 24b in the coupling rod 24 for possible lockout.

When locking the bolt from the position shown in Fig. 2, whereby the carrier means 7a is rotated clockwise, the carrier means will engage against the coupling rod in its recess 24b.

As explained above, in connection with a locking movement, the coupling arm 27 with its stop lug 27a will move to the left in the figures, ie so that the carrier means 7a passes and possibly engages against the stop lug 27a. During this passage, the latch is pushed to its end position for locking, ie so that interlocking is ensured. In the case of locking movement, whereby the control piston 20a and the clutch arm 27 have assumed the position shown in Fig. 3, in the case of continued rotational movement of the carrier member 7a this will strike the stop lug 27a, whereby, in the manner shown in Fig. 4, the drop piston is moved to its locking position 31 and the rudder arm 17.

Fig. 5 illustrates how, under the influence of the pressure of the falling mechanism, both the falling piston 9 and the control piston 20a are moved to the locking position. The locking mechanism here is actuated via the evacuation arm 39 located in the rear edge of the lock housing which is actuated by the rudder stop lug 13b for pivoting about the axis 38. The lower end 39b of the evacuation arm 39 will thereby engage a stop member 24e on the coupling rod 24. .

If this evacuation function is not desired in the lock, the evacuation arm 39 can simply be removed.

In order to effect adaptation to different center distances, the pressure / cylinder lock is understood that both the fall mechanism and the control mechanism can be substantially unchanged and that the only elements that need to be adapted are the carrier arm 31 and the evacuation arm 39.

Other embodiments where certain additional parts such as e.g. the pressure rudder arm 17 alternatively or additionally replaced falls within the scope of the basic idea of the invention according to the appended claims.

In the embodiment shown in Fig. 7, the mandrel depth is substantially greater than in the embodiment according to the other figures. However, both the fall mechanism 4 and the rule mechanism 6 are essentially unchanged.

Thus, with regard to the drop mechanism 4, essentially only the push rod 10 has been replaced by a push rod 10 'which has a substantially greater length. In addition, a special guide 41 has been introduced for the piston rod 11 of the drop piston 9, since the piston rod 11 does not reach its "ordinary" guide which consists of the recess 12a in the storage element 12.

As for the locking mechanism, as stated above, the coupling rod 24 has been replaced by another coupling rod 24 'of greater length and a larger number of holes 24'a for co-operation with the pivot shaft 22c of the transfer arm 22. In addition, the coupling arm 27 has been replaced by a coupling arm 27 'of greater length which is substantially provided by an extension part being arranged in the front end of a coupling arm of the same design as that used in the embodiment according to Figs. 1-6. Also in the embodiment according to Fig. 7 it applies that if the latch 20 were to be in an intermediate position, the carrier means 7a will, when turned, actuate the projections 34a of the control arm 34 so that complete locking of the latch 20 is performed. Thereafter, locking can take place in the usual way.

Thus, it is understood that the adaptation to the significantly greater mandrel depth has been achieved with both the fall mechanism and the rule mechanism substantially unchanged. This has been made possible by the construction of the lock according to an adapted modular system.

At the same time, the advantages stated in the introduction above have been achieved, ie full piston stroke with one-turn rotation of the key and a control function that ensures that the carrier means can always be operated from a possible intermediate position to the locking position. The gear ratio in the mechanism is advantageous, which gives low torques at key impact, especially when the drop piston 9 is moved to its locking position via the carrier arm 31 according to Fig. 4.

A locking mechanism according to the invention can therefore be adapted to motor operation by simple means, while at the same time the risk of downtime is substantially eliminated.

In such motor operation (not shown in the accompanying drawings), an electric motor is accommodated in the lock housing 2 e.g. at its upper end where space is available. A shaft extending from the motor may have a joint 505 779 13 or equivalent, so that a part belonging to the shaft follows the rear edge of the lock housing where its lower end is connected to the control arm 34 for pivoting it and thus the control mechanism 6 and - if applicable - the fall mechanism 4 between their respective end positions. The shaft emanating from the motor further has a disengagement device which ensures disengagement of the motor operation in the event of manual actuation of the control mechanism via a key.

If the engine lock has an evacuation function, disengagement must be possible at lightning speed at any time during engine operation. An evacuation arm 39 designed for a motor lock will therefore be provided with clearance between its lower part 39b and the stop lug 24e of the coupling rod 24. When free, a joint on a pushing and pulling device is snapped apart. The device feedbacks resp. make feedback attempts until limit positions plus time match the open or close command.

The control arm 34 at an engine lock can not affect the drop mechanism 4 for locking the drop piston 9. In the engine lock, therefore, the control mechanism 6 will actuate the carrier arm so that the drop piston 9 has assumed a locked position at the same time as the control piston 20a.

In the case of an engine lock, it also applies that when the carrier means 7a has left its parking position - e.g. shown in Figs. 2, 5 and 6 - the engine must not be able to start.

In the embodiments of the invention shown and described above, the control mechanism has been actuated via a cylinder lock and / or motor. Other effects, e.g. by means of a knob from one side is also possible. In the case of locks provided with an evacuation function, ie when using an evacuation arm 39, however, rotational action of the lock is not permitted according to current rules.

An important feature of the described embodiments is that the coupling arm 27 provided with the abutment member 27a is driven by the control arm 34 or vice versa and that it can be used for several mandrel depths. The stop member 27a has been imparted to the shape shown in the drawing in order not to give rise to a gap and to allow a large gear ratio in the case of one-turn rotation. It is also important that the interlock arm 32 must be able to fall down despite the lock 20 being braked when locked. In this way, good forced control is obtained when the lock is locked. The arrangement further ensures that the carrier means 7a does not end up in the recess 24c in the coupling rod 24 if evacuation were to be made at the same time as opening with a key from the outside, i.e. influencing the mechanism by one person on each side of the door.

Those skilled in the art will appreciate that other embodiments of the invention are possible within the scope of its basic idea as set forth in the appended claims.

Claims (10)

505 779 Patent claims Locking mechanism comprising: a) a drop piston (9) actuated by a spring via a spring-actuated pressure row (13), a pressure rod (10) and a pressure row arm (17), b) a carrier means (7a) via a cylinder lock (5) actuated control mechanism (6), which control mechanism comprises: c) a control (20) controlled for rectilinear movement, provided with a control piston (20a) and abutment means (20b), d) a coupling rod (24) with a recess (24b) for engaging the carrier means (7a) for displacing the coupling rod (24) between two end positions, e) a transfer arm (pivotally connected to the coupling rod (24) hinged about a shaft (21) located at one end 22) with a portion (22a) engaging between the stop means (20b) of the bolt (20) for transmitting and exchanging the movements of the coupling rod (24) to the bolt (20), f) cooperating with the transfer arm (22), around a pin (43) pivotable interlocking arm (32) for the latch (20), which interlocking arm (32) in the locking position of the latch prevents depression of this and which during the pivoting movement of the transfer arm for locking the bolt (20) pivots to a release position which allows the locking movement of the bolt, g) a coupling arm (27) provided with a stop member (27a) which at its one end is supported pivotable about a shaft (26) and also movable together with the coupling rod (24), so that during a locking movement of the bolt (20) it moves to a position in which the abutment means (27a) can be passed by the drive means (7a) of the cylinder lock (5) ) and ensures that the latch (20) is in its unlocked position and, in the case of a locking movement of the latch (20), assumes a position in which the stop means (27a) in the case of continued rotational movement of the carrier means in the locking direction (27) about its pivot axis (26) located at one end, characterized by 5Û5 779 16 h) that the locking mechanism is constructed according to a modular system adapted to different mandrel depths, wherein at different mandrel depths a coupling rod (24) with one or more alternative joint attachment points (24a) to the transfer arm or several coupling rods (24, 24 ') of different lengths, each with one or more such alternative joint attachment points (24a, 24'a), is interchangeably connectable resp. connectable to the transfer arm (22). Locking mechanism according to claim 1, characterized by a control arm (34) pivotable about a shaft (33) at one end, which at its other end receives a guide pin (23) which is connected to the rear of the coupling rod (24), the transfer arm ( 22) opposite end, so that the coupling rod (24) forms part of a parallelogram link mechanism with four pivot points (21, 22c, 33, 23). Locking mechanism according to claim 2, characterized in that the control arm (34) has a projection (34a) with such a position that it is actuated by the driver means (7a) when the key is turned and not completely locked, so that the control arm (34) drives the locking mechanism to the fully locked position, in which engagement between the carrier means (7a) and the recess (24b) of the coupling arm is ensured. Locking mechanism according to one of Claims 1 to 3, characterized in that the locking mechanism (6) is otherwise substantially unchanged at different mandrel depths, with the possible exception of the coupling arm (27). Locking mechanism according to one of Claims 1 to 4, characterized in that a push rod (10) with a length adapted to the current mandrel depth is interchangeably applicable between the pressure rudder (13 and the pressure rudder arm (17) during the fall mechanism. (4) otherwise at different mandrel depths is essentially unchanged. Locking mechanism according to one of Claims 1 to 5, characterized in that at different center distances between the pressure of the falling mechanism (4) and the cylinder locking core of the locking mechanism (6) there is a carrier arm which can be pivoted about an axis (30). (31) with a length adapted to the current cc distance interchangeably arranged. Locking mechanism according to claim 6, provided with an evacuation arm (39) between the pressure rudder (13) of the falling mechanism (4) and the coupling rod (24) of the locking mechanism (6), characterized in that evacuation arms (39) of different lengths are in the area of the rear edge of the lock housing is interchangeably applicable to a pivot shaft (38). Locking mechanism according to claim 6 or 7, characterized in that the pivotable carrier arm (31) has a member at one end, e.g. a projection (3la), arranged to be actuated by the coupling arm (27) during its pivoting movement under the action of the carrier means (7a) for pivoting the carrier arm (31), which carrier arm (31) has at its other end a stop means (3lb) for engagement with the pressure rudder arm (17) acting on the piston (9), so that the pivoting of the carrier arm (31) causes retraction of the piston (9). Locking mechanism according to one of Claims 1 to 8, provided with motor drive, an electric motor being accommodated in the lock housing (2), characterized in that a shaft extending from the motor is connected to the control arm (34) for pivoting via a release device. of this and thus the rule and possibly the fall mechanism (4; 6) between its / their end positions. Locking mechanism according to claim 9, characterized in that the disengagement device ensures disengagement of the motor operation in the event of manual actuation of the control mechanism (6) via a key.