CN111236743B

CN111236743B - Locking mechanism for handle

Info

Publication number: CN111236743B
Application number: CN202010107025.7A
Authority: CN
Inventors: 于江成; 柯金霖; 杨小军; 唐行微; 张仲桢; 卢燚钧
Original assignee: Commercial Aircraft Corp of China Ltd; Shanghai Aircraft Design and Research Institute Commercial Aircraft Corporation of China Ltd
Current assignee: Commercial Aircraft Corp of China Ltd; Shanghai Aircraft Design and Research Institute Commercial Aircraft Corporation of China Ltd
Priority date: 2020-02-21
Filing date: 2020-02-21
Publication date: 2021-04-20
Anticipated expiration: 2040-02-21
Also published as: CN111236743A

Abstract

The present invention provides a locking mechanism for a handle, comprising: a frame; a rotation rod assembly including a rotation rod and a latch; a button assembly disposed between the rotating rod and the mechanical frame in a radial direction inside the mechanical frame, and including a button disposed around the rotating rod; wherein, locking mechanical system is including locking the state and the unblock state under the locking the state, the dwang is because it is located the inside of button and can't make its rotate, and under the unblock state, the button can be pressed to expose the dwang, thereby can the via the rotation of dwang drives the hasp is right the handle unblock. By means of the locking mechanism, the two-step locking and unlocking function can be realized, the operation reliability is high, and the external interference resistance is high. In addition, the locking mechanism is compact in structure and can be locked at a low cost.

Description

Locking mechanism for handle

Technical Field

The invention relates to a locking mechanism for locking and unlocking a handle, which is used in particular in highly reliable positions, such as doors or flaps of aircraft.

Background

In areas where safety requirements are high, such as aircraft, there are often hatches or flaps that need to be opened and closed. To accomplish the opening and closing, this is typically accomplished by means of a handle.

For example, a handle used at an aircraft door may be tilted at one end by directly depressing the other end of the handle, thereby enabling an operator to grasp the one end of the handle and rotate it to open the door. When it is desired to close, the other end is then pressed directly to return it to its original position (usually without significant protrusion from the aircraft surface). Therefore, no special locking mechanism is provided for the handle.

However, it is understood that sometimes the entire circumference of an aircraft or a local location such as a door may be flushed for cleaning purposes. However, when the water pressure is excessive, it may cause an unexpected depression of one end of the handle due to the impact of the water. In addition, water may enter the inside of the handle due to excessive water pressure, thereby damaging the structure of the handle.

For this reason, it is necessary in the field of aircraft, for example, to provide such handles with a special locking mechanism.

For example, locking mechanisms for locking a flap or handle on an aircraft are known. However, the locking mechanism often takes the form of a single operation, the operation and structure of which mainly involves:

the locking element is actuated by a pressing or pulling operation, so as to unlock or lock.

The locking element is driven to act through rotating operation, so that unlocking or locking is realized.

Locking the handle or flap by means of an integrated keyed locking mechanism.

By setting the resistance means in the locked position, the handle or flap can be operated as long as the external operating force is greater than the resistance force.

However, in any of the above-described locking mechanisms, locking and unlocking can be performed by a single-step operation, which is not reliable enough for situations where the operation is complicated, the external load varies, or the reliability is high.

There is therefore a continuing need in the field of aircraft and the like where safety requirements are high to provide a reliable locking mechanism which is easy to operate but which at the same time prevents incorrect unlocking due to external factors or operator error.

Disclosure of Invention

The present invention provides a locking mechanism for a handle, comprising: a frame; a rotating lever assembly disposed within the mechanism frame, the rotating lever assembly including a rotating lever and a latch, the rotating lever being rotatable about a fixed axis of rotation, the latch being fixedly connected to the rotating lever such that rotation of the rotating lever causes the latch to also rotate about the axis of rotation, and rotation of the latch causes the handle to be locked or unlocked; a button assembly disposed between the rotating rod and the mechanical frame in a radial direction inside the mechanical frame, and including a button disposed around the rotating rod; wherein, locking mechanical system is including locking the state and the unblock state under the locking the state, the dwang is because it is located the inside of button and can't make its rotate, and under the unblock state, the button can be pressed to expose the dwang, thereby can the via the rotation of dwang drives the hasp is right the handle unblock.

By means of the locking mechanism, the two-step locking and unlocking function can be realized, the operation reliability is high, and the external interference resistance is high. In addition, the locking mechanism is compact in structure and can be locked at a low cost.

Preferably, the button and the swivelling lever are configured so as not to be able to rotate relative to each other, the button assembly further comprising a self-locking element, the self-locking element being fixedly connected with the button, the self-locking element comprising a self-locking state in which the self-locking element prevents rotation of the button and thus rotation of the swivelling lever.

By means of the self-locking element, an additional self-locking function can be provided to further prevent or allow rotation of the swivelling levers, if desired.

In some advantageous embodiments, the self-locking element is configured to protrude from the button in a radial direction, and a locking groove for receiving the self-locking element is provided on the chassis in a circumferential direction, in which state the self-locking element cannot move in the circumferential direction relative to the locking groove.

The self-locking element can thus be arranged in a very compact manner inside the machine frame and can provide a deliberate blocking of the rotation of the rotary lever in a simple manner by means of the locking groove of the machine frame itself.

In particular, the locking groove may extend along only a portion of the height of the gantry (locking groove depth D is shown in fig. 5-6 by way of example), while the self-locking element can be moved downwards relative to the locking groove to leave the self-locking position in the locking groove, so that the button and the swivelling lever can be rotated, and can also be moved upwards relative to the locking groove to enter the self-locking position in the locking groove, so that the rotation of the button and the swivelling lever is prevented.

Thereby, when the push button is not pushed down to a predetermined extent, the rotating lever still cannot be rotated, thereby further improving the reliability and the anti-interference of the locking.

Advantageously, the gear rack may comprise a first locking groove and a second locking groove, said second locking groove being spaced apart from said first locking groove in a circumferential direction by an angle, whereby, upon downward movement of said self-locking element out of said self-locking state in said first locking groove, said button and said swivelling lever can be swiveled through said angle, so that said self-locking element can again be brought into said self-locking state by means of said second locking groove.

By means of the two spaced first locking grooves and the two spaced second locking grooves, two actions of unlocking and locking can be completed within a small angle range, and therefore the whole locking process of an operator on the handle is simplified.

It is particularly preferred that the circumferential angle of the spacing between the first and second locking grooves is between 10 and 30 degrees. This small angle is very convenient for the operator to complete unlocking and re-locking in a short time.

In some embodiments, the button assembly may further comprise a resilient mechanism having one end fixed to the button and an opposite end disposed at a fixed location relative to the button, the resilient mechanism for providing a restoring force for upward movement of the button when depressed.

Therefore, the spring mechanism can keep the button in a self-locking state all the time, thereby improving the reliability of the locking mechanism.

In particular, the self-locking element may be biased towards said carriage by said resilient means when leaving said self-locking condition, so as to be stopped by said carriage, thereby holding said push-button in a depressed position. In this way, the stop for the self-locking element can be provided by means of the structure of the machine frame itself, so that a compact and low-cost design is obtained.

It is also advantageous that in the locked state, the top surface of the swivelling lever can be flush with the top surface of the push button.

Thereby, a flat profile of the locking mechanism is provided, which on the one hand meets aesthetic requirements and on the other hand also provides good aerodynamic properties.

In particular, the locking slot may be formed downwardly from the top surface of the frame, so that the operator can see the unlocking or locking of the self-locking element from the outside, thereby facilitating the smooth operation of the whole operation.

Furthermore, the self-locking element may be configured as a self-locking tab integrally formed with the button, thereby providing a low cost and robust construction.

In addition, locking mechanical system can also be used for providing the pivot of axis of rotation, the dwang cover is established in the pivot. In this way, a stable rotation of the swivelling lever about the fixed swivel axis can be achieved with a simple construction.

Drawings

FIG. 1 illustrates a schematic top view of a locking mechanism for locking and unlocking a handle according to the present invention;

FIG. 2 illustrates a perspective view of a locking mechanism associated with a handle according to one embodiment of the present invention;

FIG. 3 illustrates a perspective view of a locking mechanism associated with a handle with a mechanical frame of the locking mechanism removed for clarity, according to one embodiment of the present invention;

FIG. 4 illustrates a schematic top view of a self-locking element of a button assembly and a locking slot on a mechanism frame according to one embodiment of the present invention;

FIG. 5 shows an internal cross-sectional view of a locking mechanism according to one embodiment of the present invention, wherein the button is not depressed; and

fig. 6 shows an internal cross-sectional view of a locking mechanism according to an embodiment of the invention, wherein the push button has been pressed and the rotating lever is exposed.

It should be noted that the drawings referred to are not all drawn to scale but may be exaggerated to illustrate aspects of the present invention, and in this regard, the drawings should not be construed as limiting.

List of reference numerals:

100 a locking mechanism;

200 a handle;

10 a framework;

12 a first locking groove;

14 a second locking groove;

20 rotating the rod;

30 a latch;

40 a rotating shaft;

50 buttons;

60 a self-locking element;

70 an elastic mechanism;

d lock groove depth.

Detailed Description

Although the invention has been described in the context of locking or unlocking the handle of an aircraft door or flap, it will be appreciated that the locking mechanism of the invention may be used in any application where the handle is rotated to lock or unlock, particularly where security is a requirement.

As best shown in fig. 3, the locking mechanism 100 includes a latch 30, the latch 30 being of a construction well known in the art. That is, the latch 30 may be rotated by itself to disengage the latch 30 from its engaged position with the handle 200, thereby allowing the handle 200 to freely pivot about its own pivot axis.

The locking mechanism 100 according to the present invention includes a frame 10. Herein, the term "mechanism housing 10" refers to a structure in any form for housing the various elements of the locking mechanism 100, such as, but not limited to, a frame structure or a housing form structure.

In the embodiment shown in fig. 2, the mechanism frame 10 is configured as a substantially solid of revolution (except for a partial area), for example, substantially cylindrical. However, the shape of the frame 10 is not limited thereto, and for example, the cross-section thereof may be rectangular, oval or other irregular shape. Further, when the mechanism frame 10 according to one embodiment of the present invention is configured in the form of a frame, the inside thereof is hollow, but the frame body thereof can accommodate other members. Generally, however, the frame 10 is not openworked or meshed to protect the components contained therein and to prevent dust and water from entering the interior.

Hereinafter, the term "circumferential" refers to a direction along the periphery of the mechanism frame 10, and the term "radial" refers to a direction generally toward the center of the mechanism frame 10 or a direction opposite thereto, i.e., radial, rather than axial (i.e., height) of the mechanism frame 10.

The locking mechanism 100 according to the present invention further includes a rotating lever assembly disposed inside the machine frame 10 (i.e., in the hollow space of the machine frame 10). The swivelling lever assembly comprises a latch 30 of the type described above and a swivelling lever 20. In the present invention, the term "rotating lever" refers to any member that an operator can hold to rotate, particularly a member that is elongated in the height direction of the mechanism frame 10, such as a rod-like member.

It is understood that the cross section of the rotating lever 20 of the rotating lever assembly is not necessarily circular, but may be various shapes such as a rectangle, an ellipse, a polygon, and the like. When the cross-section of the swivelling lever 20 is designed to be non-circular, it is on the one hand convenient for the operator to hold it for rotation, and on the other hand it is also possible to provide a rotationally fixed (i.e. non-rotatable relative to each other) connection between the swivelling lever 20 and a push button described in detail later on.

In addition, the rotary rod 20 of the rotary rod assembly can be rotated about a fixed axis of rotation. The dwang assembly latch 30 can be fixedly attached (or integrally formed) with the dwang 20. Due to the fixed connection, when the rotating rod 20 rotates, the rotating rod 20 also rotates the latch 30 around the same fixed rotation axis, and the rotation of the latch 30 can finally lock or unlock the handle 200 of the aforementioned type. For example, in the embodiment shown in FIG. 3, clockwise rotation of the latch 30 is used for unlocking, while counterclockwise rotation of the latch 30 is used for locking.

In a preferred embodiment, the axis of rotation may be provided by a shaft 40 also located inside the frame 10. The shaft 40 is fixed relative to the frame 10 to provide a fixed axis of rotation at all times. In this embodiment, the rotating rod 20 is preferably sleeved on the rotating shaft 40 and can rotate around the rotating shaft 40.

For a reliable locking action, the locking mechanism 100 of the present invention further includes a button assembly. The button assembly is also arranged inside the mechanism frame 10 and, seen in space, between the swivelling levers 20 and the mechanism frame 10 in a radial direction, as is best shown in fig. 5-6. Particularly advantageously, the swivelling levers 20 and the push buttons 50 (and the swivel shafts 40, if present) are arranged centrally in the space inside the machine frame 10.

The button assembly comprises a button 50, which button 50 may be arranged around the swivelling lever 20. In a preferred embodiment, the swivelling levers 20 are received in a form-fitting manner within the push buttons 50. For example, the button 50 includes a circular hole at a central position thereof, and the circular rotating lever 20 may be received in the circular hole.

Furthermore, as schematically shown in fig. 2, 5 and 6, at least one of the push button 50 and the turning lever 20 may extend from above or below beyond the height range of the gantry 10, but may also be located completely inside the gantry 10.

As best shown in fig. 5-6, the button 50 may extend a distance along the height of the mechanism frame 10 to define its thickness. The actual thickness of the button 50 may be set as needed, and may be, for example, a thin button.

It will be understood, however, that the cross-sectional shape of the button 50 of the present invention need not be circular as shown in fig. 1, but may be any suitable shape. The button 50 is movable up and down in the height direction of the mechanism frame 10. For example, when the operator presses the button 50, the button 50 moves downward from the initial position of fig. 5 to the operating position exemplarily shown in fig. 6.

The lock mechanism 100 according to the present invention includes two states, namely, a locked state and an unlocked state, and can be switched between the two states:

in the locked state of the lock mechanism 100, as shown in fig. 2 and 5, the operator cannot hold or grasp the rotating lever 20 from the outside of the lock mechanism 100 (but may touch the top surface thereof) because the rotating lever 20 is located inside the push button 50, being surrounded by it.

In other words, the swivelling levers 20 cannot be turned because they are located inside the push button 50 (in the self-locking state by means of self-locking elements, for example in the form of locking tabs and locking slots, the exposed swivelling levers still cannot be turned because the push button cannot be turned, as will be explained in more detail below, but it should be noted that the invention is not limited to the way by means of self-locking elements).

In the preferred embodiment, in this locked condition, the top surface of the swivelling lever 20 is flush with the top surface of the button 50, thereby providing an aerodynamically clean, proj ectionless locking mechanism 100, as best shown in fig. 5. It is understood that the top surface of the rotatable lever 20 may be lower than the top surface of the button 50. In any case, however, the rotating lever 20 does not protrude beyond the push button 50 in the locked state, so that the operator can grasp it for rotation.

In the unlocked state of the lock mechanism 100, the operator presses (i.e., moves down) the aforementioned button 50. The button 50 can translate relative to the rotating lever 20, so that the rotating lever 20 is exposed relative to the button 50, so that the operator can grasp the rotating lever 20 to rotate it, thereby rotating the latch 30 that is driven to be secured thereto, and thus opening the handle 200.

By means of the push-button construction around the swivelling levers 20, it is achieved that the swivelling levers 20 are not rotated undesirably in the locked state (for example due to any external forces or environmental factors) in order to largely avoid incorrect operation, which is essential for aircraft applications with high safety requirements. In particular, a two-step operation of pressing and rotating is required regardless of whether locking or unlocking is performed, which greatly improves the safety and reliability of locking.

Further, the present invention provides a more optimized two-step locking and unlocking operation. For this reason, the button 50 and the rotating lever 20 should be configured so as not to be rotatable relative to each other (but to be translatable or slidable relative to each other). In addition, the button assembly further comprises a self-locking element 60, which self-locking element 60 is fixedly connected (but preferably integrally formed) with the button 50.

The self-locking element 60 of the button assembly comprises a self-locking state in which the self-locking element 60 effectively prevents the button 50 from rotating, and thus the rotatable lever 20 is also prevented from rotating because the button 50 and the rotatable lever 20 cannot rotate relatively. In other words, due to the self-locking element 60, even if the button 50 is pressed for unlocking, the exposed rotating lever 20 cannot rotate due to the inability of the button 50 to rotate in the self-locking state, thereby further avoiding malfunction and ensuring safety.

In the embodiment as shown in fig. 4-6, the self-locking element 60 is configured to protrude in a radial direction from the button 50. In particular, the self-locking element 60 may be configured in the form of a self-locking tab integral with the button 50. Correspondingly, the mechanism frame 10 is provided with a locking groove along the circumferential direction for accommodating the self-locking element 60. In the aforementioned self-locking state, the self-locking element 60 cannot move in the circumferential direction relative to the locking groove, i.e. the button 50 fixedly connected to or integrated with the self-locking element 60 cannot rotate because the self-locking element 60 is located in the locking groove.

As best shown in fig. 5-6, the locking slot of the mechanism frame 10 extends along only a portion of the height of the mechanism frame 10. Preferably, the locking slot is open downwardly from the top surface of the frame 10 (i.e., extends a distance downwardly from the top) so that the locking slot is visible from the exterior (see, e.g., fig. 4).

As previously described, the self-locking element 60 is fixedly coupled to the button 50 such that the self-locking element 60 moves downward when the button 50 is depressed and the self-locking element 60 moves upward when the button 50 is restored. Thus, although the self-locking element 60 cannot move in the circumferential direction relative to the locking groove, the self-locking element 60 can move downward relative to (or along) the locking groove to leave a self-locking condition in the locking groove. When the self-locking state is released, the button 50 and the rotating lever 20 can rotate because the self-locking element 60 is no longer blocked by the locking groove. It will be appreciated that the self-locking element 60 can also be moved upwards relative to the locking groove to (re) enter a self-locking state in the locking groove, thereby preventing rotation of the push button 50 and the swivelling lever 20.

In the embodiment shown in fig. 4, the mechanism frame 10 may include more than one locking slot, but may include a plurality of locking slots, including, for example, the first locking slot 12 and the second locking slot 14 shown in the figures. The second lock groove 14 is angularly spaced from the first lock groove 12 in the circumferential direction. The angle of the interval is preferably in the range of 10 to 30 degrees.

In the embodiment comprising two locking grooves, after the self-locking element 60 is moved downwards to leave the self-locking state in the first locking groove 12, the button 50 (together with the self-locking element 60) and the swivelling lever 20 can be rotated through an angle (clockwise rotation as shown in fig. 4) such that the self-locking element 60 again enters the area of the second locking groove 14, and thus the self-locking element 60 can be brought into the self-locking state again (or the locked state of the locking mechanism 100) by/via this second locking groove 14.

Therefore, to perform the two-step unlocking, the operator first presses the button 50 to expose the rotating lever 20. At this point, the button 50 must be depressed to displace the self-locking element 60, which is fixedly attached to the button 50, downward to a position out of the keyway (e.g., slide down the keyway and out of the keyway). Then, the operator grasps the rotating lever 20 and rotates it. At the same time as the swivelling levers 20 rotate, the push buttons 50 with their self-locking elements 60 also rotate freely. Advantageously, this rotation is clockwise. More advantageously, this rotation only has to be performed through a small angle of rotation, for example 10 to 30 degrees. Thereby, the latch 30 fixedly coupled to the rotating lever 20 is also rotated by a corresponding angle, thereby opening the handle 200 and completing the entire unlocking process.

When locking is required, corresponding to the above steps, first, through the above rotation angle, the self-locking element 60 can reach the position of the lock slot (preferably another lock slot different from the previous lock slot), and both the self-locking element 60 and the button 50 are moved upward, so that the self-locking element 60 enters the lock slot again. Since the button 50 has been returned upward, the rotating lever 20 is no longer exposed with respect to the button 50, thereby completing the entire process of locking.

Thus, it can be understood that the operation direction and the operation manner of the two operations of locking and unlocking are different, and therefore the entire lock mechanism 100 is strong against external disturbance. In addition, the locking mechanism 100 of the present invention is also compact in design, occupies a small space, is highly portable and adaptable in an aircraft, and is particularly suitable for locations requiring a flat contoured surface, achieving both functionality and aesthetics.

In order to achieve the return of the button 50 and its self-locking element 60 upwards, the button assembly further preferably comprises a resilient means, the resilient means 70 preferably being a spring (e.g. a helical spring). One end (the upper end shown in fig. 5-6) of the spring mechanism 70 is secured to the button 50 (shown in fig. 5-6 as being secured to the lower surface of the button 50, although other suitable locations are contemplated), while the opposite end (the lower end shown in fig. 5-6) of the spring mechanism 70 is disposed at a fixed location relative to the button 50 (e.g., may also be a location on the mechanism housing 10 or other fixed location). Thus, the resilient mechanism 70 may be used to provide a restoring force to the upward movement of the button 50 when depressed.

When the self-locking element 60 is disengaged from the locking groove, i.e. when the self-locking element 60 is in the self-locking state, the self-locking element 60 can be biased toward the mechanism frame 10 by the aforementioned elastic mechanism 70 so as to be stopped by the mechanism frame 10, thereby keeping the button 50 at the pressed position.

For example, the self-locking element 60 can be pushed by the elastic means 70 against the bottom of the transition between two locking grooves of the machine frame 10 and stopped by it. For example, the transition portion projects radially inward from the periphery of the airframe 10 to provide such a stop.

It is understood that the self-locking element 60 may also have a different structure than the above, as long as it prevents the rotation of the button 50 and the rotation of the rotation lever 20 in the self-locking state.

Although the invention has been described with reference to the embodiments of the locking mechanism for a handle on an aircraft shown in the various figures, it should be understood that embodiments within the scope of the invention are also applicable to locking mechanisms having similar structure and/or function.

The foregoing description has set forth numerous features and advantages, including various alternative embodiments, as well as details of the structure and function of the devices and methods. The intent herein is to be exemplary and not exhaustive or limiting.

It will be obvious to those skilled in the art that various modifications may be made, especially in matters of structure, materials, elements, components, shape, size and arrangement of parts including combinations of these aspects within the principles described herein, as indicated by the broad, general meaning of the terms in which the appended claims are expressed. To the extent that such various modifications do not depart from the spirit and scope of the appended claims, they are intended to be included therein as well.

Claims

1. A locking mechanism (100) for a handle (200), comprising:

a machine frame (10);

a rotating lever assembly arranged in the machine frame (10), wherein the rotating lever assembly comprises a rotating lever (20) and a latch (30), the rotating lever (20) can rotate around a fixed rotating axis, the latch (30) is fixedly connected with the rotating lever (20), so that the rotating lever (20) can drive the latch (30) to rotate around the rotating axis, and the latch (30) can lock or unlock the handle (200);

characterized in that the locking mechanism (100) further comprises:

a button assembly arranged between the swivelling lever (20) and the machine frame (10) in a radial direction inside the machine frame (10) and comprising a button (50), the button (50) being arranged around the swivelling lever (20);

wherein the locking mechanism (100) comprises a locked state in which the swivelling lever (20) cannot be rotated due to its position inside the button (50), and an unlocked state in which the button (50) can be pressed down to expose the swivelling lever (20) so that the latch (30) can be driven via the rotation of the swivelling lever (20) to unlock the handle (200).

2. The locking mechanism (100) according to claim 1, wherein the button (50) and the swivelling lever (20) are configured non-rotatable relative to each other, the button assembly further comprising a self-locking element (60), the self-locking element (60) being fixedly connected with the button (50), the self-locking element (60) comprising a self-locking state in which the self-locking element (60) prevents a rotation of the button (50) and thus of the swivelling lever (20).

3. The locking mechanism (100) according to claim 2, wherein the self-locking element (60) is configured to protrude from the button (50) in a radial direction, a locking groove for receiving the self-locking element (60) being provided in the machine frame (10) in a circumferential direction, in the self-locking state the self-locking element (60) being immovable in the circumferential direction relative to the locking groove.

4. A locking mechanism (100) according to claim 3, wherein the locking groove extends only along a part of the height of the machine frame (10), and the self-locking element (60) is movable downwards relative to the locking groove to leave the self-locking condition in the locking groove, thereby enabling the button (50) and the swivelling lever (20) to be rotated, and the self-locking element (60) is also movable upwards relative to the locking groove to enter the self-locking condition in the locking groove, thereby preventing the rotation of the button (50) and the swivelling lever (20).

5. The locking mechanism (100) according to claim 4, wherein the chassis (10) comprises a first locking groove (12) and a second locking groove (14), the second locking groove (14) being spaced apart from the first locking groove (12) in a circumferential direction by an angle, whereby the button (50) and the swivelling lever (20) can be swiveled through said angle after the self-locking element (60) has been moved downwards to leave the self-locking state in the first locking groove (12), so that the self-locking element (60) can again be brought into the self-locking state by means of the second locking groove (14).

6. The locking mechanism (100) of claim 5 wherein the angle is between 10 degrees and 30 degrees.

7. The locking mechanism (100) of any one of claims 1 to 6 wherein the button assembly further comprises a resilient mechanism (70), one end of the resilient mechanism (70) being fixed to the button (50) and the opposite end of the resilient mechanism (70) being disposed in a stationary location relative to the button (50), the resilient mechanism (70) being adapted to provide a restoring force for upward movement of the button (50) when depressed.

8. The locking mechanism (100) according to any one of claims 1 to 6, wherein in the locked state, a top surface of the swivelling lever (20) is flush with a top surface of the push button (50).

9. The locking mechanism (100) of any of claims 3 to 6 wherein the locking slot opens downwardly from a top surface of the chassis (10).

10. The locking mechanism (100) according to any one of claims 2 to 6, wherein the self-locking element (60) is configured as a self-locking tab integrally formed with the button (50).

11. The locking mechanism (100) according to any of claims 1 to 6, wherein the locking mechanism (100) further comprises a rotating shaft for providing the axis of rotation, the rotating rod (20) being sleeved on the rotating shaft.