WO2014005638A1

WO2014005638A1 - Latch mechanism and method to open a latch mechanism

Info

Publication number: WO2014005638A1
Application number: PCT/EP2012/063130
Authority: WO
Inventors: Adam LINNÅSEN
Original assignee: Industrilås I Nässjö Aktiebolag
Priority date: 2012-07-05
Filing date: 2012-07-05
Publication date: 2014-01-09

Abstract

The invention is based on the inventor's realization that by providing a latch mechanism 1 comprising two latch bolts and two pawls arranged on two parallel axes, and by designing the latch mechanism 1 so that it can be opened from a closed position into an open position by applying a torque directly onto one of the axes around which the latch bolts and pawls are mounted, a compact latch mechanism 1 which does not suffer from shearing forces can be provided.

Description

LATCH MECHANISM AND METHOD TO OPEN A LATCH MECHANISM

Technical Field

The present invention relates to a door latch, and particularly to a rotary door latch suitable for use in a vehicle door.

Background

The doors in vehicles are required to be securely shut during driving. In order to enable a securely shut door, state of the art presents a door latch provided with two rotary latch bolts swivably mounted on a respective shaft enabled to engage with a pawl mounted on the opposite latch shaft to obtain a strong lock. By doing this, the lock obtains a locking effect by both symmetric latches, each secured by the other's rotation since the pawl prevents opening of the latch when an opening rotation is attempted, but only opens completely when the pawl has been allowed to unlock from the tooth by releasing the engagement. In state of the art, the disengagement of the pawl is achieved via a release lever, connected to an arm, pivoting around a third axis, and that releases a spring that retains the engagement of the latch and the associated pawl when the release lever is pushed or pulled.

However, the design used in state of the art with a release lever of this type requires a rather large amount of space. Since required space in a vehicle is a desired parameter to minimize, small latch mechanisms are desirable in a vehicle door.

Thereby, there is a need for a more compact type of a rotary latch mechanism for use in a vehicle door.

Summary

It is an object of the present invention to provide an improved solution that alleviates the mentioned drawbacks with present devices. Furthermore, it is an object to provide a rotary latch with a more compact release

arrangement. It is also an object of the present invention to provide an improved release system to said device. Moreover there is an object to provide a method of opening a door latch mechanism.

The invention is defined by the appended independent claims.

Embodiments are set forth in the dependent claims, in the following

description and in the drawings.

The invention is based on the inventor's realization that by providing a latch mechanism comprising two latch bolts and two pawls arranged on two parallel axes, and by designing the latch mechanism so that it can be opened from a closed position into an open position by applying a torque directly onto one of the axes around which the latch bolts and pawls are mounted, a compact latch mechanism which does not suffer from shearing forces can be provided.

According to a first aspect of the invention, there is provided a latch mechanism, comprising a first latch bolt, which is rotatable about a geometric axis between an open position and a locking position, and which comprises at least one first latch tooth. The latch mechanism further comprises a second latch bolt, which is rotatable about a second geometric axis between an open position and a locking position, and which comprises at least one second latch tooth. Moreover, the latch mechanism comprises a first pawl which is rotatable about the first axis between a locking position, wherein the first pawl engages the second latch tooth, and an opening position, wherein the first pawl is disengaged from the second latch tooth. The latch mechanism further comprises a second pawl, which is rotatable about the second axis, between a locking position, wherein the second pawl engages the first latch tooth, and an opening position, wherein the second pawl is disengaged from the first latch tooth. Further, the latch comprises biasing means for biasing the first and second pawls towards their respective locking position, wherein the first pawl comprises a first shaft portion, whose centre line is aligned with the first geometric axis. The first latch bolt is rotatable about the first shaft portion. The second pawl comprises a second shaft portion, whose centre line is aligned with the second geometric axis. The second latch bolt is rotatable about the second shaft portion. At least one of the shaft portions comprises torque transfer means adapted for receiving a torque for causing the pawls to move away from their respective locking position.

By providing the pawl with torque transfer means, through the shaft portion, it enables rotation of the pawl by applying a torque directly onto the pawl. For instance, by integrating the torque transfer means of the pawl with the first or second shaft portions, the shaft may be turned by having a torque applied to it, and directly transferring the rotation to the pawl.

By such integration, precious space may be saved due to the absence of additional shafts and levers that may be used to provide a rotation to the pawl. Instead, the shaft portion that is already available may be used, and consequently saving the amount of parts to be assembled.

Furthermore, additional shafts and levers may require additional connecting links, and thereby cause increasing leverage that act upon such connecting links and the pawl. This may in turn cause shear forces to arise that affect the links and the shafts, and subsequently may damage and cause unwanted fracture of the shafts.

Therefore, by avoiding such additional shafts, damaging shear forces may be avoided. This may in turn lead to longer technical life of the latch and may extend service and maintenance intervals. The torque transfer means may be connected to any, or both, of the pawls, which means that the torque may be applied to any of the shafts, and provide the same disengaging effect to any of the pawls.

In one embodiment of the invention, the first and second latch bolts each has a jaw, for retaining a striker, and a striker engaging portion located towards the centre of the latch relative to the jaw. The striker engaging portion is adapted to cause the latch bolt to rotate in a closing direction, when an inwardly directed force is applied to the striker engaging portion.

By having a latch bolt with a jaw, for example placed at a distance from the shaft, the striker, that may hit the latch bolt to be latched, may be enclosed by the jaws.

The striker engaging portion of the jaw, when stricken by a striker, may be adapted to cause the latch bolt to rotate and cause the jaws to close around the striker so that the jaw surrounds the striker. By having the striker engaging portion be a part of the latch bolt, an immediate response by the striker to the latch bolt may be enabled. And thus, the direct force of the striker may determine the rotation of the latch bolt, and thereby to what extent the jaws may close around the striker. As a consequence, the latch bolt may pivot into a position that may enable the pawl to engage with a tooth on the latch bolt in a locking position and thereby preventing the striker from escaping the latch.

The pawl may be restrained towards the tooth by the biasing means until the biasing means may be released from the pawl and the pawl may be disengaged from the tooth.

In another embodiment, the first and second jaws are arranged so that when the first and second latch bolt are rotating in a respective closing direction, the jaws are brought towards each other to bring the latch mechanism towards a locked position.

Since the pawls may act upon direct response from the striker, the jaws may also rotate in a closing direction. Due to their construction, the jaws may simultaneously rotate towards each other so that they may form an enclosure around the striker, when fully closed.

In another embodiment, the first and second jaws are adapted to, in their closed position, at least in part overlap each other, as seen in a plane perpendicular to the axes.

By letting the first and second jaws overlap when in their closed position, the jaws may be further secured from accidental release of the striker or breakage of the jaws. This may be particularly useful if a large force from the striker acts upon said jaws and hence may cause the jaws to break at their tip. For instance, such force may arise when attempting to open the latch mechanism in a wrong manner. The jaws may then be slightly elongated, designed to be brought side by side so that damaging the tips may be avoided.

In another embodiment, first and second shaft portions are integrated with said first and second pawls, respectively. By having a shaft that is integrated with the pawl, any movement of the shaft may directly affect the pawl. For instance, when wanting to disengage the pawl from the tooth of the latch bolt, any movement of the shaft in an opening direction may apply to the pawl. Thereby the amount of parts available may be reduced. Also it may reduce the number of intermediate parts that may cause additional force and leverage onto the pawl or any other part in the latch.

However, it may be possible that the pawl and the shaft are two separate parts, closely mounted together for any shaft movement to cause direct response with the pawl, as well as the shaft and pawl may be formed from a single piece of material. This chosen solution may be selected due to structural advantages with the selected solution.

In yet another embodiment, the first latch bolt is mutually identical with the second latch bolt.

By letting the two latch bolts be identical, the number of different parts in the latch mechanism may be reduced. Also, if the latch bolts at the same time are symmetrical, the rotation may be completely simultaneous if the force from the striker is evenly distributed onto the latch mechanism. The latch mechanism may further be symmetric by having all included parts be mutually identical. That is, the first and second pawls, the first and second shafts respectively and the first and second latch bolts may be mutually identical. Further, they may be assembled in a way that enables symmetric and simultaneous movement.

Thereby, the force of the striker and the force of the pawls acting upon the teeth may be more evenly distributed on the two arrangements with a latch bolt, a shaft and a pawl, which in turn may lead to less wear of the shafts. Also, by adapting the two latch bolts, pawls and shafts to be identical, it may lead to a simplified assembly process with fewer parts to consider.

Furthermore, by providing a latch that is entirely symmetrical with two identical latch bolt-pawl-arrangements, the latch mechanism may, due to its symmetry in four directions, be mounted in a vehicle door having any side facing up or down. In a further embodiment, the first pawl is mutually identical with the second pawl.

In a further embodiment, the biasing means comprises at least one biasing element arranged to mutually provide a torque on said first and second pawl in a locking direction about the respective axis.

For instance, the biasing element may be located on the respective ends of the latch mechanism, each pushing a respective pawl in a locking direction.

In one embodiment, the biasing element is a resilient member such as a coil spring, gas spring, or a rubber element.

The biasing element may be a resilient element, made from a resilient material. This is to enable a firm engagement between the pawl and the tooth, and yet a possibility to easily relieve the engagement in a controlled manner. By having a resilient biasing element, it also may entail that the pawl may immediately spring back in a locking direction when the shaft is released after having been turned. The resilient element may however, due to its resilience, yield to the force when the tooth is about to engage. Such resilient material may be for instance a rubber element, coil spring, or another type of spring that may be suitable, for instance a gas spring.

In one embodiment, the first and second shaft portions are provided with a coaxial cavity, in which the torque transfer means is provided to enable applying a torque onto said pawl in line with said shaft portion.

By having the shafts, on which the pawls are mounted, provided with a coaxial cavity, such as a spline, a keyed point or other connector means, this cavity may facilitate rotation of the shaft. For instance, rotation may be performed by inserting or in some other way connect an opening means to aid turning of the shaft, such as a keying device or an elongated pin in order to allow for direct releasing of the pawl. The cavity may run through the entire length of the shaft, or at least in part in order to allow insertion of a device to aid turning of the shaft. By having a coaxial cavity that may be accessible from both ends, manoeuvring of the shaft and pawl may be done from either side of the latch. In one embodiment the first and second pawl further comprises a guiding arrangement and a stopper, wherein the guiding arrangement is adapted to transfer any movement between the first and second pawls for enabling simultaneous and synchronized rotation of the first and second pawls independently of the origin of the torque. The stopper is adapted to allow rotation of the pawl in a locking direction up to a predetermined angle.

By having the pawls provided with a guiding arrangement, the pawls may, regardless of which of the pawls that is rotated, co-dependently rotate in a simultaneous and symmetric movement. The movement may further be controlled by a stopper that may restrict any extreme movement that may cause damage to the pawl. The guiding arrangement may be designed in a number of ways, for instance by having a raised portion each pawl and a corresponding slot on to receive the raised portion. Any movement of the pawl may thus be restricted to the length of the slot.

In one embodiment, the guiding arrangement comprises a guiding slot and a raised portion, wherein the guiding slot of said first pawl is adapted to receive the raised portion of said second pawl, and the guiding slot of said second pawl is adapted to receive the raised portion of said first pawl.

In one embodiment, the latch mechanism is enclosed in a housing, which is adapted for mounting in a door or a door frame.

The housing may be designed to allow for simplified assembly and for simplified use of the latch. For instance, the housing may be provided with a number of apertures in order to allow access to the shaft portions. Possibly the housing may allow for access to the shaft portions from both sides of the latch.

In one embodiment, the latch bolt comprising at least one intermediate tooth, for enabling at least one intermediate position between the open position and the closed position.

By having at least one intermediate tooth, the latch may be brought in an intermediate position. The intermediate position may be a security feature of the door latch. For instance that the latch may be brought into the intermediate position when the striker may strike the latch bolts with a relatively small force, and cause them to rotate towards a locking position, but the force may be too small to cause the biasing element to yield fully. The pawl may the engage with a tooth located before the locking tooth, closing the jaws halfway, but yet enough to restrain the striker from escaping.

In one embodiment, the latch further comprises a spring connector, adapted to connect the latch bolts with each other. The spring connector may be adapted to synchronize rotation between the first and second latch bolts and to aid rotation into an open position.

By connecting the latch bolts, the rotation of the latch bolts may be synchronised. This is to ensure that they open and close simultaneously, so that the operation of the latch mechanism may be smooth. Also the spring connector may be slightly tensioned so that the spring connector attempts to bring the latch bolts towards the sides when open. Thereby, the spring connector prevents the latch from accidentally closing.

According to a second aspect of the invention, there is provided a door or a door frame comprising a latch mechanism according to the invention.

In one embodiment, the door further comprises a latch opening system comprising a torque source means, such as a handle, wheel, wrench, knob or a motor, wherein the pawl and the torque source means are adapted to be connected via an engaging axle, enabling torque to be transferred from said torque source means to said pawl.

According to a third aspect of the invention, there is provided a vehicle having a door comprising a latch mechanism according to the invention.

A further aspect of the invention is to provide a method for unlocking a door latch from a closed position, wherein the door latch has a first pawl which, in a locking position, is engaging a first tooth on a corresponding second latch bolt, a second pawl which, in a locking position, is engaging a second tooth on a corresponding latch bolt. The method comprises applying a torque to at least one of said first and second pawl, which torque is applied to a shaft portion of the pawl. The centre line of the shaft portion is aligned with a geometric axis, around which the shaft portion is pivotable. The torque is directed so that the pawl is brought in an opening direction so that the bias of the pawl towards the tooth is counteracted, and thereby the pawl and the tooth are disengaged. Rotation of the latch bolt into an open position is thereby enabled.

By opening the latch mechanism through applying a torque aligned with the centre line of the shaft portion, the torque is directed directly onto the pawl, which prevents any forces that otherwise may arise from additional shafts and levers to damage the mechanism.

According to an aspect of the method according to the invention the torque on a first or second pawl is transferred to opposite second or first pawl through a guiding arrangement adapted to transfer movement between the first and second pawl independently of its origin, thereby causing a

corresponding rotation at the opposite pawl, enabling disengagement of opposite pawl and tooth. Brief description of the drawings

The invention will in the following be described in more detail with reference to the enclosed drawings, wherein:

fig. 1 is a perspective view of a latch mechanism in an open position, fig. 2 is a top view of a latch mechanism in a closed position, fig. 3 is a perspective view of a latch mechanism in an open position, with a lid on,

fig. 4 is an exploded view of a latch mechanism,

fig. 5 is a top view of a latch mechanism in an open position, and fig. 6 is a perspective view of a system of a latching mechanism, mounted on a door.

Detailed description of embodiments

The present invention will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, like numbers refer to like elements.

The latch mechanism 1 according to the invention is described in fig. 1 In fig. 1 , the latch is shown in an open state. The latch 1 comprises a first and a second latch bolt 2a, 2b, each pivotally arranged on a respective shaft portion 4a, 4b. On the respective shaft portions, first and second pawls 3a, 3b are arranged opposite to one of the latch bolts 2a, 2b.

The pawl 3 and the latch bolt 2 are swivable in relation to each other. Each latch bolt 2a, 2b is provided with a number of teeth 6, which are engagable with the tip of the associated pawl 3 on the opposite shaft. When mounted in the latch, the teeth and the engageable pawl 3 are situated towards the back of the latch. Together the latch bolt 2 and the engagable associated pawl 3 constructs a latch bolt/pawl arrangement 30a, 30b.

Further, the latch comprises two biasing elements 5. The biasing element 5, which in fig. 1 is a helical coil spring, is in a compressed biased state, and acts upon a shoulder 18 of the pawl 3 to push the tip 17 towards the centre of the latch 1 into engagement with one of the teeth 6.

The shaft portions 4 in fig. 1are hollow, forming a coaxial cavity 10, which is adapted to receive an opening means 40, on which a torque is applied, to aid turning of the shaft 4. The coaxial cavity 10 may be provided with a torque transfer means 11 in the shape of a boss that allows for the opening means 40 that may have a corresponding channel, to transfer a torque to the shaft 4, to aid turning of the shaft 4.

The coaxial cavity 10 may run through the entire length of the shaft or, if required, the cavity may only run through part of the shaft. By having a cavity that is accessible from both ends of the shaft, turning of the shaft is enabled from any end. However, if required, the cavity may only be adapted to run through part of the cavity. Alternatively, the cavity may be exchanged for some other spline or a keyed point, such as a vertical slot or pin

arrangement suitable to receive an opening means 40. Alternatively, if suitable, the shaft 4 may be elongated to allow for turning of the shaft 4. In fig. 2, the latch is shown in a closed state. The latch is brought into a closed position by having a foreign element, such as a striker (not shown), to strike a striker engaging portion 8 of the latch bolt 2. The striking force may cause the latch bolt 2 to rotate in a closing direction, and cause a tooth 6 to push the biased pawl 3, so that the pawl 3 engages with a tooth 3. The striking force is thus bigger than the biasing force of the biasing element.

The first pawl 3a may be integrated with the first shaft portion 4a, and the second pawl 3b is integrated with the second shaft portion 4b. However, the construction of the integrated pawl 3 and shaft portion 4 may, if needed, be adapted to a corresponding construction with a shaft 4 and a pawl 3 as two separate parts, which may be tightly mounted together in order to ensure any movement of the shaft to be transferred to the pawl 3. This solution may be considered if any manufacturing method or material is more

advantageously used in that manner. However, any solution may be chosen, where the pawl 3 is directly affected by any torque applied to the shaft 4. Also, the latch mechanism may be made from any material that may be suitable for the design and the dimensioning based on the use of the latch mechanism. The latch mechanism, an its parts may be formed from a plastic material, but any type of material suitable for use in a door may be used. Further, as seen in fig. 2 each latch bolt 2 is provided with a jaw 7, adapted to, in a closed state, enclose a striker which generally may be mounted on a corresponding door frame. The jaw 7 comprises a striker engaging portion 8. The striker engaging portion 8 may be adapted so that, when the latch is in an open state, the striker engaging portion 8 may receive a striker and, by the force applied from the striker, cause the latch bolt 2 to rotate in a closing direction. The jaw 7 of the first and second latch bolts 2 may, when the latch is closing, be brought towards each other and enclose the striker, preventing it from escaping the latch. The jaw in fig. 1 , has a curved shape in order to obtain a firm close of a rounded striker. However, it is possible that the jaw 7 may be of a different shape, such as triangular or a straight jaw, whichever may be suitable. The jaws on the first and the second latch bolt 2 as seen in fig. 1 and 2 may be adapted to overlap each other, when the latch is in a closed state. As seen in the latch in fig. 2 this may be done by having a portion of the jaw cut out, in order to receive a corresponding elongated portion on the opposite jaw, so that an overlap is formed.

By letting the jaws overlap, the latch may be stronger towards a force, outwardly applied by the striker that may arise when for instance a door is pulled when the latch is closed. However, in an arrangement that require less strength, an alternative is that the jaws leave a slight gap or possibly may be face to face. The overlap may also be formed in any other way that may be suitable, for instance by having the tip of the jaw to be cone shaped, in order to fit an identical cone shaped tip on the opposite jaw.

In fig. 3 a latch mechanism fully enclosed in a housing 20 and a lid 21 can be seen. Further, an opening means 40 onto which a torque may be applied, adapted to transfer the torque to the torque transfer means 1 1 on the pawl 3, is shown. The opening means 40 may be formed in any way that may be suitable to enable the shaft portion 4 of the pawl 3 to be rotated. Also, the opening means 40 may be adapted to receive a torque source, either directly or possibly via an axle 41. Alternatively, the torque source is directly arranged onto the shaft portion 4. The torque source may be any kind of device that applies a torque onto the shaft portion 4 such as a manpowered handle, a screw, knob, a motor or the like.

Fig. 4 shows one embodiment on how the latch 1 may be assembled. There may be a housing 20, suitable to enclose the latch mechanism 1. The housing may be provided with access holes 22, adapted to provide access to the shaft portions 4. On the housing there may be a lid 21 placed, also provided with access holes 22 in order to provide access to the shaft portions from the opposite side. The access holes 22, 23 are placed in line with the shafts 4 and the axes Y1 , Y2.

As further seen in fig.4, the first latch bolt/pawl-arrangement 30a is mounted in a first location, and the second latch bolt/pawl-arrangement 30b is mounted on top of the first latch bolt/pawl-arrangement 30a upside-down so that the first latch bolt 2a is located opposite to the second latch bolt 2b. The two arrangements 30a, 30b are thus mounted mirrored to each other.

Near the lateral ends, two biasing elements 5 are arranged to push against a shoulder 18 of the pawl 3, so that the pawls may be biased towards a tooth 6. The biasing element may be constructed differently. For instance there may be only one spring, arranged to bias both pawls. Also, the biasing element may be some other type of resilient element such as a rubber element, or another type or shape of spring, such as a helical spring, conical spring, gas spring, torsion spring, compression spring, a flat spring or the like.

Further, fig. 4 shows a spring connector 12 arranged to hold the two latch bolts 2a, 2b. The spring connector 12 enables a synchronised

movement between the latch bolts 2. Also, the spring connector 12 may be slightly tensioned to attempt to bring the latch bolts 2 towards the sides of the latch 1. This may be to ensure that the latch bolts 2 stay in an open position, ready to receive a striker, and don't accidentally close.

Furthermore, the first and second latch bolt/pawl arrangements 30a, 30b are both identical in construction. By having two identical latch bolt/pawl arrangements, any forces that may arise from the striker, or the biasing elements may be distributed equally on the two identical arrangements, that may lead to less wear and tear of the latch mechanism. Also, by having identical arrangements 30a, 30b, there may be a simplified assembly operation since a less number of different parts may be needed.

However, if circumstances would require, the two arrangements may vary. For instance, the first and second latch bolts 2 or first and second pawls 3 may be designed differently, hence not identical, depending on the dimensioning of forces and such, as well as the number of teeth 6 on the first and second latch bolts 2 may vary.

Fig. 6 shows an example on a door latching system, where the latch mechanism 1 is arranged on the inside of a vehicle door 50, with the jaws 3, currently in a locked position and facing outwards. In one of the shaft portions, an opening means 40 for receiving a torque is arranged. The opening means 40 is adapted to transfer a torque from a torque source to the shaft portion 4 of the pawl 3. The torque may be applied by manpower through a handle that may transfer the rotating movement via an axle to the opening means, or directly to the pawl 3 if that may be suitable. The torque may also be applied by an arrangement with a motor, a knob, a wrench, a screw type connection or the like. The torque may be applied to any of the shaft portions, leading to the same opening operation by having the pawls guide each other through a guiding arrangement adapted to dependency transfer movement between the pawls and thereby cause a corresponding rotation at the opposite pawl 3, and thus enabling disengagement of opposite pawl 3 and tooth. In fig. 6 is also shown an example of the jaws overlapping each other, when in a closed position.

Typically, a door latch mechanism 1 is mounted in a vehicle door 50, and a striker (not shown), is mounted in an associated door frame. Upon closing the door 50, the striker strikes towards the striker engaging portion 8, whereby the latch mechanism 1 closes around the striker. Upon closing the vehicle door 50, the striker strikes towards the striker engaging portions 8 and the latch bolts 2 pivots around their respective axes and closes the jaws around the striker.

In the closed position, the pawls 3 engage a tooth on the respective latch bolt 2. The latch mechanism 1 is thereby in a locked position, and do not open until the pawls are disengaged from the teeth.

Disengagement of the pawls may occur when a shaft portion 4 of a pawl 3 is rotated in an opening position, allowing the striker to escape from the jaws, and the door may be pushed open. Alternatively, the latch

mechanism 1 may instead be arranged on a door frame and the

corresponding striker may be arranged on the door.

The latch mechanism 1 may be used in any type of door that may need latching, such as a cabinet door, vehicle door, compartment door or the like.

In the drawings and specification, there have been disclosed

embodiments and examples of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for the purpose of limitation, the scope of the invention being set forth in the following claims.

Claims

1. A latch mechanism, comprising:

a first latch bolt (2a), which is rotatable about a first geometric axis (Y1) between an open position and a locking position, and which comprises at least one first latch tooth (6a),

a second latch bolt (2b), which is rotatable about a second geometric axis (Y2) between an open position and a locking position, and which comprises at least one second latch tooth (6b),

a first pawl (3a), which is rotatable about the first axis (Y1) between a locking position, wherein the first pawl (3a) engages the second latch tooth (2b), and an opening position, wherein the first pawl (3a) is disengaged from the second latch tooth (2b),

a second pawl (3b), which is rotatable about the second axis (Y2) between a locking position, wherein the second pawl (3b) engages the first latch tooth (6a), and an opening position, wherein the second pawl (3b) is disengaged from the first latch tooth (6a),

biasing means for biasing the first and second pawls (3a, 3b) towards their respective locking position,

characterised in that

the first pawl (3a) comprises a first shaft portion (4a), whose centre line is aligned with the first geometric axis (Y1),

wherein the first latch bolt (2a) is rotatable about the first shaft portion

(4a),

the second pawl (3b) comprises a second shaft portion (4b), whose centre line is aligned with the second geometric axis (Y2),

wherein the second latch bolt (2b) is rotatable about the second shaft portion (4b), and

at least one of the shaft portions (4) comprises torque transfer means (11) adapted for receiving a torque for causing the pawls (3a, 3b) to move away from their respective locking position.

2. Latch mechanism (1) according to claim 1 , wherein said first and second latch bolts (2a, 2b) each further comprises a jaw (7), for retaining a striker, and a striker engaging portion (8) located towards the centre of the latch relative to the jaw (7), wherein the striker engaging portion (8) is adapted to cause said latch bolt (2a, 2b) to rotate in a closing direction, when an inwardly directed force is applied to said striker engaging portion (8).

3. Latch mechanism (1) according to claim 2, wherein the first and second jaws (7) are arranged so that upon rotation of said first and second latch bolt (2a, 2b) in a respective closing direction, said jaws (7) are brought towards each other to bring said latch mechanism (1) towards a locked state.

4. Latch mechanism (1) according to any of the claims 2 or 3, wherein the first and second jaws (7) are adapted to, in their closed position, at least in part overlap each other, as seen in a plane perpendicular to the axes (Y1 , Y2).

5. Latch mechanism (1) according to any of the preceding claims, wherein said first and second shaft portions (4) are integrated with said first and second pawls (3a, 3b), respectively.

6. Latch mechanism (1) according to any of the preceding claims, wherein said first latch bolt (2a) is mutually identical with said second latch bolt (2b).

7. Latch mechanism (1) according to any of the preceding claims, wherein said first pawl (3a) is mutually identical with said second pawl (3b).

8. Latch mechanism (1) according to any of the preceding claims, wherein said biasing means comprises at least one biasing element (5) arranged to mutually provide a torque on said first and second pawl (3a, 3b) in a locking direction about the respective axis (Y1 , Y2).

9. Latch mechanism (1) according to any of the preceding claims, wherein said biasing element (5) is a resilient member such as a coil spring, gas spring, or a rubber element.

10. Latch mechanism (1) according to any of the preceding claims, wherein said first and second shaft portions (4) are provided with a coaxial cavity (10), in which said torque transfer means (10) is provided to enable applying a torque onto said pawl (3a, 3b) in line with said shaft portion (4).

11. Latch mechanism (1) according to any of the preceding claims, wherein said first and second pawl (3a, 3b) further comprises a guiding arrangement (15) and a stopper (16), wherein said guiding arrangement (15) is adapted to transfer any movement between said first and second pawls (3a, 3b) for enabling rotation of said first and second pawls independently of the origin of the torque, and wherein the stopper (16) is adapted to allow rotation of the pawl (3a, 3b) in a locking direction up to a predetermined angle.

12. Latch mechanism (1) according to claim 10, wherein said guiding arrangement (15) comprises a guiding slot (13) and a raised portion (14), wherein the guiding slot (13) of said first pawl (3a) is adapted to receive the raised portion (14) of said second pawl, and the guiding slot (13) of said second pawl (3b) is adapted to receive the raised portion (14) of said first pawl (3a).

13. Latch mechanism (1) according to any of the preceding claims, wherein said latch mechanism (1) further comprises a housing (20), in which said rotary latch (1) is enclosed, which is adapted for mounting in a door (50) or a door frame.

14. Latch mechanism (1) according to any of the preceding claims, wherein said latch bolt (2a, 2b) comprising at least one intermediate tooth (9), for enabling at least one intermediate position between said open position and said closed position.

15. Latch mechanism according to any of the preceding claims, further comprising a spring connector (12), adapted to connect the first and the second latch bolts with each other, said spring connector (12) being adapted to synchronize rotation between said first and second latch bolts and/or to maintain an open position.

16. A door or a door frame comprising a latch mechanism (1) according to claims 1-15.

17. A door according to claim 16 further comprising a latch opening system comprising a torque source means, such as a handle, wheel, wrench, knob or a motor, wherein said pawl (3a, 3b) and said torque source means are adapted to be connected via an engaging axle (41), enabling torque to be transferred from said torque source means to said pawl (3a, 3b).

18. A vehicle having a door comprising a latch mechanism (1) according to any of the claims 1-15.

19. Method for opening a door latch (1), from a closed position, wherein said door latch (1) having a first pawl (3a), engaging a first tooth (6) on a corresponding second latch bolt (2b), and a second pawl (3b), engaging a second tooth (6) on a corresponding first latch bolt (2a), comprising

applying a torque to at least one of said first and second pawl (3a, 3b), which torque is applied to a shaft portion (4) of said pawl (3a, 3b), which centre line of said shaft portion (4) is aligned with a geometric axis (Y , Y2), around which said shaft portion (4) is pivotable, wherein said torque is directed in an unlocking direction so that said bias of said pawl (3a, 3b) towards said tooth (6) is counteracted, and thereby said pawl (3a, 3b) and said tooth (6) are disengaged, whereby rotation of said latch bolt (2a, 2b) into an open position is enabled.

20. Method for opening a door latch (1) according to claim 16, wherein said torque on a first or second pawl (3a, 3b) is transferred to opposite second or first pawl (3b, 3a) through a guiding arrangement adapted to dependently transfer movement between said first and second pawl (3a, 3b), thereby causing a corresponding rotation at the opposite pawl (3a, 3b), enabling disengagement of opposite pawl (3a, 3b) and tooth (6).