Claims:We Claim:

1. A mechanism (100) for tilting a cabin (150) of a vehicle, the mechanism (100) comprising:
a first bracket (1) movably connected to the cabin (150);
a second bracket (2) movably connected to a frame (3) of the vehicle;
a resilient member (4), wherein one end of the resilient member (4) is connected to each of the first bracket (1) and the second bracket (2), wherein the resilient member (4) is configured to displace the second bracket (2) corresponding to displacement of the first bracket (1); and
a transmission screw (5) coupled to the first bracket (1), the transmission screw (5) is configured to operationally displace the first bracket (1) between a first position (9a) and a second position (9b), wherein displacement of the first bracket (1) between the first position (9a) and the second position (9b) varies tension of the resilient member (4) to tilt the cabin (150) of the vehicle.

2. The mechanism (100) as claimed in claim 1, wherein the first bracket (1) is disposed on a first guideways (6), rigidly attached to the cabin (150) of the vehicle.

3. The mechanism (100) as claimed in claim 1, wherein the second bracket (2) is movably disposed on a second guideways (7), rigidly attached to the frame (3) of the vehicle.

4. The mechanism (100) as claimed in claim 1, comprises a torsional bar, mounted on the frame (3) of the vehicle, wherein torsional bar is configured to pivotally operate the cabin (150) between an elevated condition and a rest condition.

5. The mechanism (100) as claimed in claim 1, wherein the first bracket (1) and the second bracket (2) are defined with roller supports, to covert rotary motion imparted by the transmission screw (5) into a linear motion along the first guideways (6) and the second guideways (7).

6. The mechanism (100) as claimed in claim 1, wherein the first position (9a) and the second position (9b) of the first bracket (1) are defined on either side of a pivotal axis about the torsion bar (8).

7. The mechanism (100) as claimed in claim 1, wherein operation of the transmission screw (5) in a first direction displaces the first bracket (1) from the first position (9a) to the second position (9b).

8. The mechanism (100) as claimed in claim 7, wherein the resilient member (4), on displacement from the first position (9a) to the second position (9b) along with the first bracket (1), is configured to expand and move the cabin (150)to the elevated condition.

9. The mechanism (100) as claimed in claim 1, wherein operation of the transmission screw (5) in a second direction displaces the first bracket (1) from the second position (9b) to the first position (9a).

10. The mechanism (100) as claimed in claim 9, wherein the resilient member (4), on displacement from the second position (9b) to the first position (9a) along with the first bracket (1), is configured to contract and move the cabin (150) to the rest condition.

11. A vehicle comprising a mechanism (100) to tilt a cabin (150) as claimed in claim 1.
, Description:TECHNICAL FIELD
Present disclosure relates in general to the field of automobiles. Particularly, but not exclusively, the present disclosure relates to vehicles employed with engine cabins. Further, embodiments of the present disclosure discloses a mechanism for tilting the cabin of the vehicle.

BACKGROUND OF THE DISCLOSURE
Vehicles are evolving continuously and new technologies are being implemented in order to meet consumer expectations. Compactness of the vehicle is one of the most desired and expected feature of the consumers. Conventionally, several commercial vehicles ranging from light commercial vehicle to heavy commercial vehicles have cabins or body built over ladder frame chassis. Such vehicles do not contain elongated hoods or engine bays in order to create more space for carrying loads and other goods. Hence, basic design of such commercial vehicles are configured with engines underneath the passenger cabin and in-between long members of the chassis. Additionally, in order to comply with the expectations of the consumers for compact packing, manufacturers assemble peripheral components such as, cooling systems, transmission systems, and the like underneath the cabin.

In order to access the engine and its peripheral components, the cabin needs to be tilted. Conventional vehicles having such tiltable cabins are provisioned with hydraulic mechanism or pneumatic mechanism, where operations of such mechanism would enable an operator to tilt the cabin and access the components covered therein.

However, the hydraulic mechanism and the pneumatic mechanism involve limitations such as, fluid leakage, insufficient capacity to tilt the cabin during moderate load, and the like. In addition, the hydraulic and the pneumatic mechanism may also pose some challenges during dynamic condition of the vehicle. The hydraulic and the pneumatic mechanism may not be able to damp vibrations transmitted from wheels of the vehicle to the cabins. Due to this scarcity in dynamic attenuation of the hydraulic and pneumatic mechanisms, the cabin may be subjected to wobbling during vehicle travel on uneven terrain.

The present disclosure is directed to overcome one or more limitations stated above or any other limitation associated with the prior arts.

SUMMARY OF THE DISCLOSURE:

One or more shortcomings of conventional devices or methods or systems are overcome and additional advantages are provided through the device as claimed in the present disclosure. Additional features and advantages are realized through the techniques of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered a part of the claimed disclosure.

In one non-limiting embodiment of the present disclosure, a mechanism for tilting a cabin of a vehicle is disclosed. The mechanism comprises a first bracket movably connected to the cabin, and a second bracket movably connected to a frame of the vehicle. A resilient member is included in the mechanism, where one end of the resilient member is connected to each of the first bracket and the second bracket. The resilient member is configured to displace the second bracket corresponding to displacement of the first bracket. Further, a transmission screw is coupled to the first bracket. The transmission screw is configured to operationally displace the first bracket between a first position and a second position. Additionally, displacement of the first bracket between the first position and the second position varies tension of the resilient member to tilt the cabin of the vehicle.

In an embodiment of the present disclosure, the first bracket is disposed on a first guideways, rigidly attached to the cabin of the vehicle.

In an embodiment of the present disclosure, the second bracket is movably disposed on a second guideways, rigidly attached to the frame of the vehicle.

In an embodiment of the present disclosure, the mechanism comprises a torsion bar, mounted on the frame of the vehicle. The torsion bar is configured to pivotally operate the cabin an elevated condition and a rest condition.

In an embodiment of the present disclosure, the first bracket and the second bracket are defined with roller supports, to covert rotary motion imparted by the transmission screw into a linear motion along the first guideways and the second guideways.

In an embodiment of the present disclosure, the first position and the second position of the first bracket are defined on either side of a pivotal axis about the torsion bar.

In an embodiment of the present disclosure, operation of the transmission screw in a first direction displaces the first bracket from the first position to the second position.

In an embodiment of the present disclosure, the resilient member, on displacement from the first position to the second position along with the first bracket, is configured to expand and move the cabin, to the elevated condition.

In an embodiment of the present disclosure, operation of the transmission screw in a second direction displaces the first bracket from the second position to the first position.

In an embodiment of the present disclosure, the resilient member, on displacement from the second position to the first position along with the first bracket, is configured to contract and move the cabin to the rest condition.

It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined together to form a further embodiment of the disclosure.

The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The novel features and characteristic of the disclosure are set forth in the appended claims. The disclosure itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings. One or more embodiments are now described, by way of example only, with reference to the accompanying drawings wherein like reference numerals represent like elements and in which:

Figure 1 illustrates a schematic diagram of a mechanism to tilt a cabin of a vehicle, in accordance with one embodiment of the present disclosure.

Figure 2 illustrates a magnified view of the mechanism shown in Figure 1.

Figure 3a illustrates a schematic diagram of the cabin in an elevated condition, in accordance with one embodiment of the present disclosure.

Figure 3b illustrates a magnified diagram of the mechanism in operating the cabin to the elevated condition, in accordance with one embodiment of the present disclosure.

Figure 4a illustrates a schematic diagram of the cabin in a rest condition, in accordance with one embodiment of the present disclosure.

Figure 4b illustrates a magnified diagram of the mechanism in operating the cabin to the rest condition, in accordance with one embodiment of the present disclosure.

It should be appreciated by those skilled in the art that diagrams herein represent conceptual views of illustrative mechanism embodying the principles of the present disclosure.

The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the mechanisms and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION

While the embodiments in the disclosure are subject to various modifications and alternative forms, specific embodiment thereof has been shown by way of example in the figures and will be described below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the scope of the disclosure.

It is to be noted that a person skilled in the art would be motivated from the present disclosure and modify various features of the mechanism, without departing from the scope of the disclosure. Therefore, such modifications are considered to be part of the disclosure. Accordingly, the drawings show only those specific details that are pertinent to understand the embodiments of the present disclosure, so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having benefit of the description herein. Also, the mechanism of the present disclosure may be employed in any kind of vehicle ranging from passenger vehicles to commercial vehicles, where a cabin of the vehicle may be pivotable.

The terms “comprises”, “comprising”, or any other variations thereof used in the disclosure, are intended to cover a non-exclusive inclusion, such that a device that comprises a list of components does not include only those components but may include other components not expressly listed or inherent to such device. In other words, one or more elements in the mechanism proceeded by “comprises… a” does not, without more constraints, preclude the existence of other elements or additional elements in the device.

Embodiments of the present disclosure discloses a mechanism to tilt a cabin of a vehicle. The mechanism comprises a first bracket movably connected to the cabin, and a second bracket movably connected to a frame of the vehicle. A resilient member is included in the mechanism, where one end of the resilient member is connected to each of the first bracket and the second bracket. The resilient member is configured to displace the second bracket corresponding to displacement of the first bracket. Further, the mechanism includes a transmission screw which is coupled to the first bracket. The transmission screw is operated to displace the first bracket between a first position and a second position. Additionally, displacement of the first bracket between the first position and the second position varies tension of the resilient member to tilt the cabin of the vehicle.

Henceforth, the present disclosure is explained with the help of figures illustrating a mechanism to tilt a cabin of a vehicle. However, such exemplary embodiments should not be construed as limitations of the present disclosure, since the mechanism may also be used for tilting of other components such as, but not limited to, passenger compartment doors, engine compartment door, rear door, and the like of vehicles where such need arises. A person skilled in the art can envisage various such embodiments without deviating from scope of the present disclosure.

Figure 1 is an exemplary embodiment of the present disclosure, illustrating a schematic diagram of a mechanism (100) to tilt a cabin (150) of a vehicle. The cabin (150) may be pivotally positioned on a frame (3) of the vehicle. The cabin (150), when resting on the frame (3) of the vehicle, may cover components such as, but not limited to, an engine, a radiator, fluid reservoirs, and the like, where the components may be accessible on tilting the cabin (150) about the frame (3). This configuration enables easy access and compact packaging of the components in the vehicle. Further, the cabin (150) may be mounted on a torsion bar (8), where the torsion bar (8) may be rigidly connected to the frame (3) of the vehicle. The torsion bar (8) may be provisioned at a front end of the cabin (150) [that is, front section of the vehicle] and may be configured to assist the cabin (150) to operate between an elevated condition and a rest condition, in order to access the components of the vehicle. One skilled in the art would note that, the elevated condition of the cabin (150) with respect to the frame (3) of the vehicle relates to the cabin (150) inclination of the cabin (150) at an angle with respect to the frame (3). Also, the rest condition may be defined as proximal positioning of the cabin (150) with respect to the frame (3) of the vehicle, that is, the cabin (150) of the vehicle may be substantially parallel to the frame (3) of the vehicle. In an embodiment, the torsion bar (8) may be disposed across a lateral direction of the cabin (150), where the cabin (150) may be reside on the frame (3) that may be parallelly positioned in the vehicle. The torsion bar (8) may be disposed on a base element (10), where the base element (10) may be configured to rigidly connect the torsion bar (8) to the frame (3) of the vehicle. The base element (10) may be adapted to adjust positioning of the cabin (150), in order to be substantially be oriented parallel to the frame (3) of the vehicle. Also, the torsion bar (8) may be configured to operate in conjunction with the mechanism (100) to tilt the cabin (150). The mechanism (100) may be configured to tilt the cabin (150), while the torsion bar (8) may be configured to pivot the cabin (150) between the elevated condition and the rest condition.

Referring now to Figure 2, which illustrates a detailed view of the mechanism (100) to tilt the cabin (150) of the vehicle. The mechanism (100) includes a first bracket (1) and a second bracket (2). The first bracket (1) is movably connected to the cabin (150), while the second bracket (2) is movably connected to the frame (3). In an embodiment, the first bracket (1) may be disposed on a first guideways (6), where the first guideways (6) may be rigidly connected to the cabin (150) of the vehicle. The first bracket (1) may be disposed on roller supports, to traverse on the first guideways (6). In an embodiment, the roller supports may include a plurality freely rotatable rollers which converts rotary motion into a linear motion. In similar sense, the second bracket (2) may be disposed on a second guideways (7), where the second guideways (7) may be rigidly connected to the frame (3) of the vehicle. The second bracket (2) may also be disposed on the roller supports for traversing on the second guideways (7). The roller supports may assist in linear displacement of the first bracket (1) and the second bracket (2) correspondingly on the first guideways (6) and the second guideways (7). Further, the first bracket (1) and the second bracket (2) may be connectable with one another by a resilient member (4). The resilient member (4) may be configured to selectively displace the second bracket (2) with respect to the first bracket (1), and vice versa. The resilient member (4) may be provisioned with a coupling element (11) on either side, where each of the coupling element (11) may be configured to synchronously connect the resilient member (4) with the first bracket (1) and the second bracket (2). This way, the resilient member (4) may be configured to linearly and tandemly [that is, corresponding movement with one another] displace the first bracket (1) and the second bracket (2), upon displacement of either of the first bracket (1) and the second bracket (2). In an embodiment, the coupling element (11) may be at least one of H-joint, C-joint, and the like. Additionally, the resilient member (4) may be connected with the first bracket (1) and the second bracket (2) in a non-stressed condition [that is, the resilient member (4) may not be under compressed state or tensioned state].

In an exemplary embodiment of the present disclosure, the mechanism (100) includes a transmission screw (5). The transmission screw (5) may be operationally coupled to the first bracket (1). The transmission screw (5) may be adapted to traverse through the first guideways (6) in order to selectively operate the first bracket (1) about the first guideways (6), that is, the first bracket (1) may be configured to displace on the first guideways (6), and in-turn along the transmission bar. The first bracket (1) may be displaced between a first position (9a) and a second position (9b), based on operation of the transmission screw (5). In an embodiment, the transmission screw (5), on operation in a first direction may displace the first bracket (1) from the first position (9a) to the second position (9b) [as best seen in Figure 3b]. The transmission screw (5), on operation in a second direction may displace the first bracket (1) from the second position (9b) to the first position (9a) [as best seen in Figure 4b]. Further, as the first bracket (1) may be displaced by the transmission screw (5), the resilient member (4), and in-turn the second bracket (2), may be correspondingly be displaced along the second guideways (7) to the corresponding position. Additionally, the transmission screw (5) may act as a stopper for regulating displacement of the first bracket (1) on the first guideways (6). That is, operation of the transmission screw (5) eventually regulates and varies tensioning of the resilient member (4) as the first bracket (1) and the second bracket (2) are being displaced.

The displacement of the first bracket (1) between the first position (9a) and the second position (9b) may be defined about either side of the torsion bar (8). In the illustrative embodiment, the torsion bar (8) may be defined with a pivotal axis (X-X), where the torsion bar (8) may be configured to operate the cabin (150) in response to direction of force exerted on the cabin (150) about the pivotal axis (X-X). Further, the first position (9a) of the first bracket (1) may be defined adjacent to the pivotal axis towards a rear portion of the cabin (150) [as best seen in Figure 3b], while the second position (9b) of the first bracket (1) may be adjacent to the pivotal axis towards front end of the cabin (150) [as best seen in Figure 4b] of the torsion bar (8). It may be noted that the direction and/or arrangement of the first position (9a) and the second position (9b) of the first bracket (1) may be interchanged by mere change in orientation of the transmission screw (5) or that of the resilient member (4).

Referring now to Figure 3a, which illustrates the cabin (150) in the elevated condition. The transmission screw (5) may be operated by an operator manually or may be automated through an automatic motor. The transmission screw (5) may be operated based on necessity for accessing the components of the vehicle which may be covered by the cabin (150), when the cabin (150) may be in the rest condition. On operation of the transmission screw (5) in the first direction [that is, in at least one of a clock-wise rotation or anti-clock-wise rotation], the first bracket (1) may be displaced from the first position (9a) to the second position (9b). At this juncture, the resilient member (4) may be configured to traverse along with the first bracket (1), and also correspondingly displace the second bracket (2) to the second position (9b). As the first bracket (1) may be displaced from the first position (9a) due to operation of the transmission screw (5), the first bracket (1) may traverse pass the pivotal axis of the torsion bar (8). The first bracket (1) may engage with an end of the first guideways (6), which may be proximal to the second position (9b) of the first bracket (1).

Upon continued operation of the transmission screw (5), the first bracket (1) at the second condition may be restricted from further movement. The operation of transmission screw (5) may be employed by the resilient member (4) connected to the first bracket (1), whereby the resilient member (4) may be subjected to stress due to operation of the transmission screw (5) [that is, the resilient member (4) may be configured to tension state about the second position (9b) of the first bracket (1) as best seen in Figure 3b]. Due to this stressed condition, the resilient member (4) may be configured to expand at the second position (9b) of the first bracket (1), whereby the cabin (150) may be subjected to an upward push force, which may tilt the cabin (150) about the pivotal axis of the torsion bar (8). The cabin (150), on tilting due to the state of resilient member (4), may be lifted from the frame (3) of the vehicle. As the lift of the cabin (150) reaches a critical point of the torsion bar (8), the torsion may be configured to operate the cabin (150) to the elevated condition, as best seen in Figure 3a.

Turning now to sequence of Figures 4a and 4b, which illustrates operation of the cabin (150) from the elevated condition to the rest condition. Figure 4a illustrates the cabin (150) to be in the elevated condition. That is, the first bracket (1), the second bracket (2), and the resilient member (4) may be accommodated in the second position (9b) on the first guideways (6) and the second guideways (7), respectively. The transmission screw (5) may be operated in a second direction [that is, rotated in a direction opposite to the first direction], whereby the first bracket (1) may be displaced from the second position (9b) to the first position (9a). As the first bracket (1) traverses past the pivotal axis of the torsion bar (8), the first bracket (1) may be configured to reach the other end of the first guideways (6), which may be defined proximal to the first position (9a).

As the transmission screw (5) is continued to be operated even after engagement of the first bracket (1) with the other end of the first guideways (6), the resilient member (4) [which may be in the state of tension as the cabin (150) may be at the elevated condition], may be subjected to a compressive state, as best seen in Figure 4b. The compressive state of the resilient member (4) may subject the cabin (150) to a downward pull force. Due to this downward pull force of the resilient member (4), the cabin (150) may be pivotable about the pivotal axis of the torsion bar (8). As the downward pull of the cabin (150) reaches a critical point of the torsion bar (8), the torsion may be configured to operate the cabin (150) to the rest condition, as best seen in Figure 4a.

In an embodiment, the resilient member (4) may be a coil spring, which may be connected between the first bracket (1) and the second bracket (2). It may be noted that the resilient factor of the resilient member (4) may be considered as a parameter in determining the first position (9a) and the second position (9b) of the first bracket (1) about the first guideways (6), however, the same should not be considered as a limitation.

In an embodiment, the torsion bar (8) may be pre-stressed and arranged downstream of the cabin (150), to receive the cabin (150) in the rest condition. Due to this, the torsion bar (8) may facilitate in upward lifting of the cabin (150) in addition to upward pull force exerted by the resilient member (4), for operating the cabin (150) from the rest condition to the elevated condition.

In an embodiment, the transmission screw (5) may be at least one of lead screw, ball screw, and the like.

In an embodiment, the first guideways (6) and the second guideways (7) may be fitted by means including, but not limited to, welding, brazing, fastening, riveting, and the like. Distance between the first guideways (6) and the second guideways (7) may also be considered as a parameter in determining the first position (9a) and the second position (9b) of the first bracket (1), as the resilient factor of the resilient member (4) may vary with distance to couple the first bracket (1) and the second bracket (2).

In an embodiment, due to provision of resilient member (4), in conjunction with the torsion bar (8), effort required to operate the cabin (150) between the elevated condition and the rest condition may be reduced.

In an embodiment, as the mechanism (100) involves mechanical components, problems associated with fluid leakage, such as in hydraulic mechanism (100) and pneumatic mechanism (100), may be eliminated.

In an embodiment, as the mechanism (100) includes tandem working of the resilient member (4) and the torsion bar (8), abrupt landing of the cabin (150) with respect to the frame (3) may be prevented. That is, during operation of the cabin (150) from the rest condition to the elevated condition, the resilient member (4) may be configured to delineate movement of the cabin (150). Also, during operation of the cabin (150) from the elevated condition to the rest condition, the torsion bar (8) may be configured to delineate the movement of the cabin (150).

In an embodiment, as the resilient member (4) of the mechanism (100) rigidly connects the cabin (150) with the frame (3) of the vehicle, when the cabin (150) is in the rest condition, the resilient member (4) may be configured to attenuate vibrations caused during movement of the vehicle. Therefore, negligible vibrations may be transmitted to the cabin (150), thereby wobbling of the cabin (150) may be prevented during movement of the vehicle.

Equivalents:

With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.

It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances, where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.” While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

REFERRAL NUMERALS
Particulars Numeral
First bracket 1
Second bracket 2
Frame 3
Resilient member 4
Transmission screw 5
First guideways 6
Second guideways 7
Torsion bar 8
First position 9a
Second position 9b
Mechanism 100
Cabin 150
Pivotal axis X-X