In the current state of the art a hydraulic cab tilting mechanism is known for tilting a cabin of a truck in a tilted position and for tilting back into a un-tilted position, wherein the truck is ready to drive. This mechanism can be seen in DE 197 30 499 Al.

The mechanism uses a cabin tilting cylinder which has, inter alia, a hydraulic pump, a pressure medium container for the hydraulic fluid and a double-acting lifting cylinder, in which a central lifting rod is movably provided. The lifting rod can be coupled to the cab and is connected to a piston of the lifting cylinder. The piston is housed in a cylinder housing of the lift cylinder, in which the piston can move back and forth and which is connected to a chassis of the truck. A control valve device controls the hydraulic inlet or the hydraulic outlet in cylinder chambers in front of and behind of the piston head in order to move the lifting rod either into the tilted position of the driver's cab or into the un-tilted, ready-to-travel position.

A problem of present trucks comprising such a mechanism is that the lifting cylinder can oscillate with the vibrations of the cabin on the chassis when the truck is moving, a complex hydraulic control of the inlets and outlets of the cylinder chambers is required to counteract such resonance.

Accordingly, there is a need for trucks with a cabin lifting mechanism that does not require active hydraulic control, when the truck is driving, in order to counteract cabin oscillations.

More particularly a cab, short for cabin, tilt cylinder connection is a potential noise path from chassis to cab. Even the lowest force could mean noise increase in the cab interior. One would prefer no connection at all in driving condition or at least one that has the lowest possible force level to the cab, eg a sliding connection. For cab tilting however one wants a sturdy fixed connection, which ensures a predictable and controlled cab movement during the whole tilting operation.

To this end the present invention provides a truck which is characterized in that the mechanism is arranged for reversibly bringing the piston rod into a locking engagement with the receiver, by rotating the piston rod around it’s longitudinal axis, such that a connection is established for the transfer of mechanical energy between the rod and the receiver. This mechanism prevents oscillations from reaching the chassis as the system can be prevented from forming a connection by which oscilation can be transferred from the chassis to the cabin when the truck is driven. It will be understood that the untilted position is one of ± 5 degrees tilt between the first and second structures.

With this invention a combination a purely unassisted mechanism is provided which is purely mechanical without electric or active additional hydraulic help during diving. Which is independent of cab weight and independent of cab spring stiffnesses.

Further to the above the receiver may comprise at least one first set of ridges which are arranged along the inner surface of the receiver, wherein the piston rod comprises at least one second set of ridges which are arranged along an outer surface of the piston rod at the first distal end of the piston rod, wherein the at least one first set of ridges and the at least one second set of ridges are mutually interlocking, for reversibly establishing a locking engagement. Optionally, the receiver comprises at least two first sets of ridges which are spaced apart along the inner surface of the receiver, wherein the piston rod comprises at least two second sets of ridges which are spaced apart along an outer surface of the piston rod at the first distal end of the piston rod, wherein the at least two first sets of ridges and the at least two second sets of ridges are mutually interlocking such as for reversibly establishing a locking engagement. This allows the connection for the transfer of mechanical energy to be made more rapidly than a screwing connection, similar to a bayonet mount. Commensurate with the same aspect of the invention the ridges of the at least two first sets of ridges and the at least two second sets of ridges are spaced apart from other ridge of the same set in an axial direction as defined by the piston rod, such that optionally the ridges of first sets and ridges second sets of ridges have enough space between ridges of the same set such that a ridge of another set is able to pass between them by the rotational movement of the piston rod. This allows the piston rod full rotational mobility unless axial lifting forces are exerted through the piston rod on the receiver via the first and second sets of ridges. A benefit to this is that the piston rod may be detached from the receiver when all axial forces are removed from the rod. This allows direct access to the connection components for inspection without removal of the mechanism fully or in part from the truck. The at least two first sets of ridges may be integral with the receiver, and the at least two second sets of ridges may be integral with the piston rod.

In one embodiment according to the same aspect of the invention each ridge of the at least two first sets of ridges defines a first nesting curve for a ridge of the at least two second sets of ridges. Each ridge more particularly curves along its length towards its distal ends, in an axial direction as defined by the longitudinal axis of the piston rod. The curve defines a minimum in the center of the ridge, between its two distal ends.

An other way of saying this is that the first nesting curve extends in a first plane that is non-perpendicular to the axial direction as defined by the piston rod. Concurrently in this same embodiment it is possible that each ridge of the at least two second sets of ridges defines a second nesting curve for a ridge of the at least two first sets of ridges. Each ridge more particularly curves along its length towards its distal ends, in an axial direction as defined by the longitudinal axis of the piston rod. The curve defines a minimum in the center of the ridge, between its two distal ends. Here too another way of saying this is that the second nesting curve extends in a second plane that is non-perpendicular to the axial direction as defined by the piston rod. A benefit of to the presence of these nesting curves is that connection is formed through nesting of first and second sets of ridges under the influence of a lifting force exerted by the piston rod on the receiver through the connection formed by both sets of ridges. This means that there is an optimum rotational position which is most stable during lifting operations in which the piston rod will be inclined to settle. This allows for a solid connection for a cabin lifting operation without a sort of screw tightening of the ridges. Where other connections may destabilize over time, this connection is inclined to become more stable. The same benefit may occur in a lesser manner when only one of the ridges forms a nesting curve for an opposing ridge of another set. More in general one could say that the ridges of the first sets of ridges and second sets of ridges are mutually nestable in the axial direction as defined by the piston rod in such a manner that the first and second sets of ridges center themselves relative to each other when interlocking. Here, nestable in axial direction means, that a relative movement of the ridges in axial direction results in a centering force effect, wherein the ridges align in a central position relative to each other. The first sets of ridges and second sets of ridges thus align in a preferable position as defined by a preferred angle of rotation to establish a safe locking engagement. The angle of rotation here refers to the angle of rotation of the piston rod around its longitudinal axis.

Optionally, this nestability can be a result of the first and second ridges defining a nesting curve in a first plane that is non-perpendicular to the axial direction as defined by a piston rod, and further optionally by defining a minimum in the middle of such a ridge.

However, alternatively or additionally to the above, each ridge of the sets of ridges defines on one face of the ridge a protrusion and on the opposite face a recess, such as on the middle of the respective face of such a ridge, such that the sets of ridges are only nestable in a predetermined centered position relative to each other.

Further to the same embodiment it may also be possible that the at least two first sets of ridges and the at least two first sets of ridges are arranged such as to interlock only when, in use, the piston rod assumes an angle of rotation within a first angular range of rotation of the piston rod around its longitudinal axis, such as 45 — 135 degrees with respect to an initial position defined by the rod in a position of maximal retraction into the housing. It will be understood that the initial position is characterized in that the ridges are not aligned such that the piston the ridges of different sets run free in axial movement and do not interfer with each other. A benefit is that this allows locking only within a predefined angular range. This prevents ridges of a first and second sets to coming in contact when in the fully retracted position, such as when the truck is driving. This prevents unnecessary friction between parts, which increases longevity.

Further to the above optionally the at least two first sets of ridges are spaced apart such that the at least two second sets of ridges are able to pass freely between the at least two first sets of ridges in an axial direction defined by the longitudinal axis of the piston rod when, in use, the piston rod assumes an angle of rotation around its longitudinal axis within a second range of rotation, such as 0 - 45 degrees, with respect to an initial position defined by the rod in a position of maximal retraction into the housing, wherein the first and second ranges of rotation are mutually exclusive. This also prevents unnecessary friction between parts, which increases longevity.

In one embodiment, commensurate with all previously mentioned embodiments the mechanism comprises a guide pin which extends from the receiver into the first end of the piston rod, such as to guide the axial movement of the piston rod within the receiver. This guides the piston rod in its axial and tangential movements while preventing the radial movement of the piston rod. This also prevents unnecessary friction between parts, which increases longevity, and additionally keeps the piston rod and receiver aligned.

In yet another embodiment, commensurate with all previously mentioned embodiments the mechanism comprises a rotational guide, for guiding the rotation of the piston rod, over only a first part of the sliding range of the piston rod, for reversibly bringing the piston rod into the locking engagement with the receiver from its position of maximal retraction. It will thus be understood that the piston rod is guided in its tangential movement, as a result of hydraulic forces moving the piston rod axially, from its position of maximal retraction to the position of locking engagement in which the first and second ridges interlock. In a lifting operation of the cabin the locking position can be considered to be maintained as this merely reflects the relative position of the piston rod to the receiver. As such, these positions are consecutively assumed by the piston rod during a cabin lifting operation. After locking engagement is achieved the cabin is lifted to a tilted position. Optionally, the rotational guide comprises a guide track and a guide track follower, wherein the guide track is defined as a screw-type recess at the inner bottom of the housing and wherein the track follower is defined as a screw body by the second end of the piston rod, wherein the guide track is arranged for receiving therein the guide track follower such as to establish a screw connection between the piston rod and the housing. Beneficially this allows for precise guiding of the movement towards interlocking of ridges, thus preventing ridges from becoming jammed against each other in rotational movement or from experiencing unnecessary friction. Additionally, furnishing the guide at the inner bottom of the housing and distal end of the piston rod allows the guide to remain protected and permanently lubricated by the hydraulic fluid, allowing the guide to remain precise over time. The screw body may also be called a worm, and the screw-type recess can be called a worm hole. Optionally, the guide track is integral with the housing, and wherein the screw body is integral with the piston rod. This allows for fewer moving parts.

As discussed, the rotational guide may be arranged such that, over the first part of its sliding range, the sliding movement of the piston rod requires the rotational movement of the piston rod, In such a situation optionally there may be a rotational locking means, wherein the rotational locking means is arranged for reversibly locking the rotation of the piston rod around its longitudinal axis, when in use, the piston rod is in a position of maximal retraction in the housing. This prevents the rotation of the piston rod when the piston rod is maximally retracted. The allows the ridges to be prevented from accidentally rotating into engagement. Although the locking means could in theory also be provided in the receiver, having this locking means in the housing prevents oscillations from being propagated there through to the housing. Optionally, the rotational locking means is a spring plunger provided to the housing, wherein the piston rod comprises a recess along a part of its length for being engaged by the plunger.

In yet another embodiment, commensurate with all other previous embodiments, the receiver can comprise a cover which is arranged for receiving a part of the housing, when in use, the piston rod is slid into a position of maximal retraction. This prevents contaminations from entering the mechanism.

Further advantageous aspects of the invention will become clear from the appended description and in reference to the accompanying drawings, in which:

Figure 1 shows the side view of a part of a truck according to the invention in an un-tilted position;

Figure 2 the side view of a part of a truck according to the invention in a tilted position;

Figure 3 shows a schematic drawing of the mechanism of the truck according to the invention;

Figure 4 shows part of the mechanism wherein the first and second sets of ridges are freely moveable;

Figure 5 shows part of the mechanism wherein the first and second sets of ridges are in locking engagement;

Figure 6 shows a cross sectional view of the mechanism according to Figure 4;

Figures 7A-D show various rotational positions of the piston rod in a mechanism of the truck according to the invention;

Figure 8 shows an alternative embodiment of the mechanism;

Figure 9 shows another alternative embodiment of the mechanism;

Figure 10 shows a first nesting curves of a first set of ridges;

Figure 11 shows a second nesting curves of a second set of ridges;

Figure 12 shows a second distal end of the piston rod

Figure 13 shows a rotational guide for rotational piston rod movement;

Figure 14 shows a dirt cover;

Figure 15 shows a close up view of a set of ridges in a position of misalignment;

Figure 16 shows a side view the receiver and silentblocks; Figure 17 shows an alternative embodiment for the rotational guide;

Figure 18 also shows the alternative embodiment for the rotational guide; and Figure 19 shows the alternative embodiment for the rotational guide along a different part of the piston rod and housing;

Figure 20 shows a graph representing the force with which the dampeners resist compression.

WORKING PRINCIPLE

In basic the mechanism involves a hydraulic cylinder but with a special upper and lower area. At the start of a tilting operation oil pressure is applied underneath the cylinder piston. At the bottom of the piston rod a helix shaped extension (worm) sits in a helix shaped hole (worm hole) of the cylinder tube. The oil pressure forces the piston rod to rotate while moving up. After 90° the worm has left the hole and the piston continues its way the go up without rotating. Due to the rod rotation the teeth (serration) at the top of the rod will be forced into the internal teeth of a special housing mounted to the cab floor making a sturdy connection between cylinder rod and cab. At this moment the actual cab tilting begins. The end of the tilting movement is when the end stop meets the top of the cylinder tube. Tilting back is in opposite order but now with oil pressure above the piston; both serrations stay is full contact during the whole operation until the worm meets the worm hole again. The tilting operation will be ended when the worm is completely in the worm hole due to the forced rotation. The serration at top has no contact at all anymore with the housing serration. The rod is free to move up and down with the cab movement while driving and is guided by a pin for an unambiguously movement. A sliding bushing ensures a low friction and so low forces what was the intention. Important to mention: If the rod is rotated (at the end as well as at the start of tilting) the cab rests on its springs which is a stable position (so no axial force on the rod which makes it easy to get in or out of the serration).

CABIN TILTING

Figure 1 shows the side view of a part of a truck 1. Here the truck is shown to have a first structure 3, namely a chassis, and a second structure, namely a cabin 5. The two structures are shown to articulated with respect to each other via a tilting joint 7. The truck can be seen to have a mechanism 100 which allows the first and second structure 3, 5 to be moved with respect to each other from an un-tilted position, as shown in Figure 1 to a tilted position, as shown in Figure 2 and vice verse. The mechanism 100 is shown in more detail in Figure 3 where it can be seen to have a piston rod housing 101 and an actuatable piston rod 103 which is slidably arranged in the housing. More in detail it is shown that the piston rod and piston rod housing form a hydraulic actuator. In this example the piston rod comprises a piston head 104 on which hydraulic fluid can act. In this example hydraulic fluid can be introduced in a first compartment 104.1, delimited by the housing and a first side of the piston head, to move the piston rod into a collapsed position. Hydraulic fluid may alternatively be introduced into a second compartment, delimited by the housing and a second side of the piston head, to move the piston rod into an extended position. Figure 3 shows the piston rod in its fully extended position. The mechanism also has a receiver 105 for receiving therein a first distal end 107 of the piston rod 101. It can be seen from Figures 1 and 2 that the housing is mounted to the first structure and the receiver is mounted to the second structure such that a tilting movement of first and second structures with respect to each other can be accomplished by a sliding movement of the piston rod. More specifically, extending the piston rod from the housing will cause first and second structures to assume the tilted position, and retracting the piston rod into the housing will cause the first and second structures to assume the un-tilted position. The receiver 105 is in this example substantially unmovably fixed with respect to the second structure 5, whereas the housing 101 is articulated with respect to the first structure 3. In other words, the housing 101 can pivot around a pivot point P. However, the receiver may be connected to the housing via dampening means, which allow for slight movement. Dampening means 700 are shown in Figure 14 and are discussed further below.

In Figures 4 and 5 that the piston rod 103 and receiver 105 are arranged for forming a bayonet-type connection. The mechanism 100 is arranged for reversibly bringing the piston rod 103 into a locking engagement with the receiver 105, by rotating the piston rod 103 around it’s longitudinal axis X, such that a connection is established for the transfer of mechanical energy between the rod and the receiver. Axial movement, as defined by axis X, of the piston rod and receiver with respect to each other is guided by means of a guiding rod, also known as a guide pin 109, which is extends from the receiver 105 into the first distal end 107 of the piston rod. In this example, the guide pin extends into the piston rod over such a length that, over its entire sliding range, the longitudinal axis X of the piston rod is kept to coincide with the longitudinal axis of the receiver. Since these both axis always coincide, only the longitudinal axis X of the piston rod is shown in Figures 4 and 5.

ROD AND RECEIVER LOCKING

In Figure 4 the piston rod 103 can be seen in the fully retracted position, also known as a maximally retracted position of the piston rod into the housing. The receiver 105 comprises two first sets of ridges 111 which are spaced apart along the inner surface 113 of the receiver. In this partially cross-sectional view only one of the first sets of ridges is shown. However, the two first sets of ridges would be equally spaced apart and could otherwise have been seen facing opposite each other on the inner surface 113 of the receiver. The piston rod also has two second sets of ridges 115 which are spaced apart along an outer surface 117 of the piston rod at, meaning towards, the first distal end 107 of the piston rod. The ridges of the two first sets of ridges 111 and the two second sets of ridges 115 are spaced apart from other ridge of the same set in the axial direction as defined by the longitudinal axis X, such that between two subsequent ridges of a certain set there is space there between for receiving a ridge of another set. The two first sets of ridges 111 and the two second sets of ridges 115 are to this end designed to be mutually interlocking.

Figure 5 shows the piston rod in a partially extended position, wherein the piston rod has made a 90 degree rotation around its axis X with respect to its fully retracted position as shown in Figure 4. It can be seen that at a 90 degree rotation the two first sets of ridges 111 and the two second sets of ridges 115 do indeed interlock such as to establish a connection for the transfer of mechanical energy between the rod and the receiver. The two first sets of ridges 111 are in this example integral with the receiver, and the two second sets of ridges are integral with the piston rod. However, these sets of ridges may alternatively also be separate elements furnished onto the receiver or piston rod.

In Figure 6 a cross-sectional view is shown of the receiver and piston rod in the position of Figure 4. In Figure 6 it can be seen that the two first sets of ridges form there between a clearance with a width Dl. The two second sets of ridges 115 are aligned along the piston rod opposite each other, and the ridges of each of the second set of ridges are aligned in the axial direction as defined longitudinal axis X of the piston rod, and each ridge has a width D2 measured from the most distal points of the ridge, wherein the width D1 and width D2 are chosen such that D1 is greater than D2. It can thus be seen that the two first sets of ridges 111 are spaced apart such that the two second sets of ridges 115 are able to pass freely between the two first sets of ridges 111 in an axial direction defined by the longitudinal axis X of the piston rod when, in use, the piston rod assumes at least fully retracted position as shown in Figure 4.

The two first sets of ridges 111 and the two first sets of ridges 115 are arranged such as to interlock only when, in use, the piston rod assumes an angle of rotation within a first angular range of rotation of the piston rod around its longitudinal axis with respect to an initial position defined by the rod in a position of maximal retraction into the housing. Figure 7A shows a schematic cross-sectional view of the piston rod within the receiver having assumed the initial position which is the same as the position shown in Figure 6. The piston rod thus assumes in Figure 7A an angle of rotation a which is equal to zero, with respect to an initial position defined by the rod in a position of maximal retraction. In this example the first angular range of rotation is shown to extend between 45 and 135 degrees. However, this may depend on the amount of sets of ridges. The first moment of interlocking between the first and second sets of ridges occurs as the piston rod rotates around its axis with an angle beyond 45 degrees, as shown in Figure 7B, from its initial position as shown in Figure 7A. Throughout the first range the first and second ridges interlock as can be seen from Figures 7C and 7D.

It can also be seen that the two first sets of ridges 111 are spaced apart such that the two second sets of ridges 115 are able to pass freely between the two first sets of ridges 111 in an axial direction defined by the longitudinal axis X of the piston rod when, in use, the piston rod assumes at an angle of rotation around its longitudinal axis within a second range of rotation with respect to an initial position defined by the rod in a position of maximal retraction into the housing. In this example the second range is between 0 and 45 degrees as can be seen from figures 7 A and 7B. The first and second ranges of rotation are mutually exclusive in that there is no overlap between the ranges.

Figure 8 shows an alternative embodiment of the mechanism 100’ of the truck according to the invention. In Figure 8 only differences will be discussed with respect to the mechanism 100 as shown in Figure 6. The mechanism 100’ can work as shown with only one first set of ridges 111’ and/or one second set of ridges 115’. Two first sets of ridges and two second sets of ridges are merely a reflection of an amount of first and second sets of ridges which may obtain a mechanism which prevents an axially oriented force on the piston rod to translate into a radially oriented force when, in use, the piston rod becomes connected to the receiver. In Figure 8 one can thus see only one first set of ridges 111’ and only one second set of ridges 115’.

Figure 9 shows yet another alternative embodiment of the mechanism 100” of the truck according to the invention. In Figure 9 only differences will be discussed with respect to the mechanism 100 as shown in Figure 6. In Figure 9 the two first sets of ridges as per Figure 6 are in actuality a reflection of a minimum amount of sets of ridges to prevent an axially oriented force on the piston rod to translate into a radially oriented force when, in use, the piston rod becomes connected to the receiver. Accordingly, Figure 9 shows three first sets of ridges 111” and three second sets of ridges 115”. By extension of the above, a higher number of first and second ridges is also possible. It can be seen that the sets of ridges are equally distributed around the respective inner or outer circumferential surface of the respective rod or receiver. The angle of axial rotation by the piston rod required, from an initial position of free axial movement or maximal retraction can be considered a function of the amount of sets of ridges. In this example the amount of first and second sets of ridges are equal. AXIAL NESTING OF RIDGES

Figure 10 shows a partial cross-sectional view A-A of the mechanism 100, as per Figure 7C, along the longitudinal axis X of the piston rod 103. In this Figure the piston rod 103 is omitted from view. In Figure 10 each ridge of the two first sets 111 of ridges defines a first nesting curve for a ridge of the two second sets of ridges. In this example one ridge 211 of a first set of ridges is shown as exemplary to all ridges of the first sets of ridges. The ridge 211 defines a first nesting curve 200. The ridge 211 curves, towards its distal ends 213, 215, in an axial direction Y as defined by the longitudinal axis X of the piston rod 103. The curve defines a minimum in the center of the ridge 211, between the two distal ends.

It can thus be understood from Figure 10 that a first nesting curve 200 individually defined by each ridge 211, does not curve in a plane that is perpendicular to the to the axial direction Y. Rather, the curve 200 can be considered to curve in a plane that is non-perpendicular to the axial direction Y. This non-perpendicular plane to the axial direction Y is not shown in Figure 10, but can be inferred. For the purpose of comparison the intersection between the cross-section and perpendicular plane Z is shown.

Figure 11 also shows the transparent partial cross-sectional view A-A of the mechanism 100, as per Figure 7C, along the longitudinal axis X of the piston rod 103. In this Figure the receiver 105 is omitted from view. Here it can be seen that each ridge of the at least two second sets of ridges 115 individually defines a second nesting curve for a ridge of the at least two first sets of ridges. In this example one ridge 311 of a second set of ridges is shown as exemplary to all ridges of the second sets of ridges. The ridge 311 can be seen to define a second nesting curve 300. The ridge 311 curves, towards its distal ends 313, 315, in an axial direction Y as defined by the longitudinal axis X of the piston rod 103. The curve 300 follows the ridge and defines a minimum in the center of the ridge 311, between its two distal ends. It can thus be understood from Figure 11 that a second nesting curve 300 individually defined by each ridge 311, also does not curve in a plane that is perpendicular to the to the axial direction Y. Rather, the curve 300 can be considered to curve in a plane that is non-perpendicular to the axial direction Y. This non-perpendicular plane to the axial direction Y is again not shown, but can be inferred. For the purpose of comparison the intersection between the cross-section and perpendicular plane Z is here too shown.

It can be seen from Figures 10 and 11 that the first and second curves curve in the same direction such as to allow for one curve to be nestable in the other. Since each of the first and second curves is traced out by the sharp edge of its corresponding ridge in space the edges can be found to nestable in the axial direction Y.

The nesting curve allows axial forces between sets of ridges, also separate from this particular example, to have a self-centering effect such that the minimum of each nesting curve seeks the minimum of another nesting curve.

In one example each set of ridges of the piston rod comprise four ridges. The number of ridges depends on the material quality of the ridges and the amount of force that is exerted on such ridges during tilting operations. The number of ridged of a set of ridges of the receiver depends on the spring travel of the cab, or cabin.

GUIDED ROTATION

Figure 12 shows the second distal end 127 of the piston rod 103. The manner in which the second distal end of the piston rod is designed to cooperate with the housing 101 allows the piston rod to translate axial movement as a result of hydraulic operations to automatically be translated in rotational movement of the piston without the need to manually rotate the piston rod into a locking position. The rotational guide 400 are thus arranged such that, over a first part of the sliding range of the piston rod, the sliding movement of the piston rod requires the rotational movement of the piston rod.

Figure 13 shows that the mechanism 100 has a rotational guide 400, for guiding the rotation of the piston rod 103, over only a first part of the sliding range of the piston rod, for reversibly bringing the piston rod into the locking engagement with the receiver from its position of maximal retraction. The first part of the sliding range of the piston rod is shown as the range Q wherein a bottom edge B of the second distal end 127 of the piston rod 103 can move in or opposite the axial direction Y as defined by the longitudinal axis X of the piston rod. It can be seen that as long as the piston rod is in the first sliding range, its rotational movement of the piston rod is guided by the rotational guide 400. When, in use, the piston rod 103 moves into the axial direction Y such that edge B moves outside of range Q the rotational guide becomes disassembled such that rotational movement is further entirely unguided by the rotational guide. These rotational guide can be seen to comprise a guide track 401 and a guide track follower 402. Disassembly can thus be simply understood as the situation wherein the guide track follower 402 has left the guide track 401. The guide track is in this example defined as a screw-type recess at the inner bottom of the housing 101. The track follower 402 is defined as a screw body, or screw thread, by the second distal end 127 of the piston rod 103. The guide track 401 is arranged for receiving therein the guide track follower 402 such as to establish a screw connection between the piston rod and the housing. The guide track 401 is integral with the housing 101, and the screw body 402 is integral with the piston rod 103. The piston rod and the housing are both made of stainless steel in this example, as is the receiver. The mechanism 100 can in Figure 13, as in Figure 12, be seen to have a rotational locking means 500. The rotational locking means 500 is arranged for reversibly locking the rotation R of the piston rod 103 around its longitudinal axis X, when in use, the piston rod is in a position of maximal retraction in the housing 101. The rotational locking means 500 is a spring plunger provided to the housing, wherein the piston rod comprises a recess 501 along a part of its length for being engaged by the plunger. The plunger is freed from the recess when the piston rod rotates with sufficient hydraulic force to lift the plunger, against its spring bias. This allows the piston rod to keep rotating under hydraulic forces in the axial direction Y until the piston rod has moved outside the first part Q of the sliding range.

Alternatively, the guide track follower 402’ is defined as at least one protrusion arranged on, or as part of the side, of the piston rod, and the track 401’ is defined as a recess which curves along the inner surface of the housing in the axial direction Y. This can be seen in Figures 17 and 18. Figure 17 showing a position of maximal retraction of the piston rod and Figure 18 showing the position wherein the piston rod has rotated for engaging the receiver. It can be seen that the rotational guide 400’ of this alternative may arranged anywhere along the length of the piston 103 rod and its housing 101. This can be seen in Figure 19. In Figures 17, 18 and 19 there are only differences discussed with respect to the embodiment of the rotational guide 400 as shown in Figures 12 and 13.

DIRT COVER & SUSPENSION

Figure 14 shows a cut-away view of the mechanism 100, wherein the receiver 105 has a cover 600 which is arranged for receiving a part of the housing 101 when the piston rod is slid into a position of maximal retraction. The receiver is also fitted with dampeners 700 which are made of sturdy oscillation and force dampening materials such a rubber. These dampeners are bridged between the connection of the receiver to the second structure.

The angle between cylinder and cab floor varies during spring travel and tilting by +/- 5°. The dampeners, also known as silent blocs, will take up this movement thus avoiding ridges from becoming jammed. Due to the silent blocs the ridges will relent and thus allowing different sets of ridges to match. Rotation in combination with axial travel of the piston rod will also help preventing ridges from meeting each other such that serrations confront each other.

The function of silent blocs will be further described herein below. The angle between piston rod and the second structure, usually the cabin floor, varies during spring travel (~±2°) and tilting (~±5°). The silent blocs will take up this movement thus avoiding the internal housing parts to jam. The ridges of piston rod and receiver will not always match perfectly for interlocking. Cab weight, spring stiffness and tolerances are the main cause of such imperfect matching. An example of imperfect matching can be seen in Figure 15. In this situation the receiver is enabled to move, due to interaction of the ridges, such that the ridges become aligned for interlocking. The silent blocks are to this end somewhat compressibly arranged to allow the receiver slight movement such as to allow the locking engagement to occur even in moments when serrations do not align as a result of environmental factors. In other words, due to the silent blocs the housing serration, or ridges, will relent, thus allowing both serrations, or ridges, to match for allowing locking engagement between the two. Rotation of the piston rod in combination with axial travel also is of added benefit to resolving any misalignment of sets of ridges.

Also separate from the above, and generally implementable to any embodiment of the invention is the fact that the receiver is fixed to the second structure via two noise/oscillation dampeners 700 such as to allow pivoting dampening movement Ml, as shown in Figure 16, as well as axial dampening movement M2. The dampeners may be seen as providing a form of suspension. These movements allow the receiver some co-movement with the piston rod to allow the elements for align themselves when in use the piston rod is rotated for establishing a locking engagement.

Each dampener 700 may comprise internal recesses 701 to enable the dampener to first compress, at least in the axial direction Y and/or opposite the axial direction Y, with a first spring rate up over a predefined distance determined by a dimension, such as the width of the internal recess, and wherein compression of the dampener beyond this predefined distance occurs at a second spring rate, wherein the second spring rate is higher than the first spring rate. This allows smaller movements to occur with relatively little resistance, whereas large movements are prevented.

The dampeners 700 can be seen as relevant for dampening forces exerted on the receiver during both driving and during tilting operations of the cabin of the vehicle. Figure 20 shows a graph in which the x-axis represents the amount compression in mm’s, and the y-axis represent the force with which the dampeners resist compression. It can be seen that from a certain point of compression the spring rate changes from the first spring rate R1 to the second spring rate R2. The dampener is designed such that a tilting of approximately 2 degrees with respect to a position of rest corresponds to the dampener being in the domain of the first spring rate. This means that when driving the stiffness of connection between the receiver and the cabin is determined by the first spring rate. Both movements Ml and M2 result can result in forces over the internal recesses 701. Due to the steep increase in spring rate between the first and second spring rate most of the movement associated with cabin tiling will be buffered un the first spring rate domain. However, cabin tilting may result in tilting of the receiver with approximately 5 degrees respect to a position of rest thereof which means that tilting forces may also be buffered in the domain of the second spring rate. The position of rest is herein defined as a position wherein the dampeners are fully uncompressed. Tilting of the receiver to and beyond said 5 degrees from a position of rest can in the setup of Figure 16 result in the stiffening of the connection between the receiver and the second structure 5. The internal recesses 701 of each dampener are shown in Figure 16 to be two opposing recesses which are provided specifically to buffer movements of the receiver in the directions indicated by M2. Part of movements Ml and M2 which are perpendicular to the M2 direction, such as shown by movement M3 are directly buffered with a second spring rate without first having to pass a domain of a first spring rate. The presence of the dampeners provides a maintenance free element which allows the desired stiffness of connection under forces exerted on the receiver by cabin tilting and driving. It is thus believed that the operation and construction of the present invention will be apparent from the foregoing description and drawings appended thereto. For the purpose of clarity and a concise description features are described herein as part of the same or separate embodiments, however, it will be appreciated that the scope of the invention may include embodiments having combinations of all or some of the features described. References to published material or sources of information contained in the text should not be construed as concession that this material or information was part of the common general knowledge in this country or abroad. Each document, reference or patent publication cited in this text should be read and considered by the reader as part of this text, and for reasons of conciseness the contents thereof is not repeated, duplicated or copied in this text. It will be clear to the skilled person that the invention is not limited to any embodiment herein described and that modifications are possible which may be considered within the scope of the appended claims. Also kinematic inversions are considered inherently disclosed and can be within the scope of the invention. In the claims, any reference signs shall not be construed as limiting the claim. The terms 'comprise', 'comprising' and ‘including’ when used in this description or the appended claims should not be construed in an exclusive or exhaustive sense but rather in an inclusive sense. Thus expression as 'including' or ‘comprising’ as used herein does not exclude the presence of other elements, integers, additional structure or additional acts or steps in addition to those listed. Furthermore, the words ‘a’ and ‘an’ shall not be construed as limited to ‘only one’, but instead are used to mean ‘at least one’, and do not exclude a plurality. Features that are not specifically or explicitly described or claimed may additionally be included in the structure of the invention without departing from its scope. Expressions such as: "means for ...” should be read as: "component configured for ..." or "member constructed to ..." and should be construed to include equivalents for the structures disclosed. The use of expressions like: "critical", "preferred", "especially preferred" etc. is not intended to limit the invention. To the extend that structure, material, or acts are considered to be essential they are inexpressively indicated as such. Additions, deletions, and modifications within the purview of the skilled person may generally be made without departing from the scope of the invention, as determined by the claims.