Patent Description:
It is known in the art to provide a "step assembly" or a "step assist" to commercial vehicles (e.g. a van) in order to ease access to the vehicle roof, and/or to allow a person to more easily enter or leave the vehicle, especially if the vehicle has a high ground clearance. Some of these step assemblies are fixedly mounted to a rear end of the vehicle (e.g. by means of bolts) and their position is not adjustable. Other assemblies have the problem that the step assembly, or at least a portion thereof (e.g. a central portion), needs to be removed before a trailer can be connected to the vehicle, which is inconvenient.

<CIT> discloses a stowable step for use with a vehicle, having a trailer hitch receptacle, comprising: a horizontally adjustable securement means selectively received in the trailer hitch receptacle; a vertical sleeve means secured to and extending upwardly from the securement means, said sleeve means being vertically adjustable; control means co-axial with the sleeve means, telescopically and rotatably received within said sleeve means, said control means terminating at its lower end in a step means movable, while in a substantially constant horizontal plane, in conjunction with said control means, from a stowed position beneath the vehicle to a utility position extending outwardly from the vehicle, and at its upper end a control handle which allows single handed operation, including unlatching the control means allowing rotation thereof and rotating the control means and its attached step from the stowed to the utility position; and means to latch the step in its stowed and in its latched position.

<CIT> discloses a stable, selectively extending platform for use with a motor vehicle, comprising: a first section to be removably attached to a vehicle; an elongated second section including a first end pivotably secured to the first section, said second section selectively locked in two positions, one extending outwardly from the vehicle and one beneath the vehicle; and a third section including the platform pivotably secured to a second end of the second section and selectively locked in two positions, one extending beyond the second end of the second section, whereby the platform is movable to and lockable in two positions, extending outwardly from the vehicle or stored beneath the vehicle.

<CIT> discloses a rotatable step to assist a person entering into a vehicle or climbing onto a machine comprising: a step with a nonskid tread large enough to hold both feet at once; a step support having two legs attached to one another forming an included angle of less than <NUM> degrees, with the ability to accept the step for either left or right hand use at one end of the step support, and rotatably secured to the opposite end of the step support; a locking plate having a center hole in which a pivot device may rotate, and with the ability to positively lock the step in it's several positions, and is fastened to the step support at the rotatable position; a pivot device; a pivot bar with the pivot device secured at one end, and fastened to the vehicle or machine at the opposite end.

<CIT> describes a vehicle step system with a mounting bracket and a support platform, and a method of securing the same.

<CIT> describes a step assembly including a base frame mountable to the rear of a vehicle such as a van.

<CIT> describes a foldable step assembly that is adjustably engageable with a trailer hitch.

<CIT> provides a retractable vehicle step for use in allowing a user to access a vehicle.

<CIT> describes a retractable vehicle step attachable to a rear portion of a vehicle or truck.

<CIT> describes a step arrangement for a lorry comprising an adjustable axis.

<CIT> describes a dual receiver hitch with top winch plate.

<CIT> describes a step platform assembly for attachment to a vehicle hitch assembly. The platform assembly includes a planar step platform member rigidly fastened to a coplanar linear step support member.

<CIT> describes a combined vehicle tow and step assembly in which a trailer hitch and step platform are interconnected with each other and function as a unit so as to provide both towing and step functions without the need of removal from the vehicle high mount to achieve such functions.

<CIT> describes a step or platform adapted to be mounted to the receiver of a trailer hitch selectively movable from a stowed to a deployed position without vertical movement, said platform is automatically locked in its selected position and includes a safety mechanism preventing inadvertent movement.

<CIT> describes a universal retractable step for use with the trailer hitch receptacle on automotive vehicles, wherein the step is movable from a stowed position to a utility position while remaining in the same horizontal plane.

<CIT> describes a step for a large pickup truck attachable to the side of a receiver type hitch.

<CIT> describes a vehicle side stepping bar.

<CIT> describes a trailer hitch step for vehicles having a tailgate.

<CIT> describes an auxiliary step for facilitating entering and exiting the bed of a pickup truck.

<CIT> describes a removable bumper step for vehicles comprising a rigid plate having an upper, generally planar foot supporting surface terminating in a front end.

<CIT> describes a retractable vehicle step assembly including a mounting bracket attached to a motor vehicle.

<CIT> describes a retractable step including a first and second tube member, a step platform and a retraction device.

<CIT> describes a vehicle step which is provided to lower an entrance and exit of a vehicle and which functions as a stepping-stone when getting on and off the vehicle.

The present invention has the object to provide a step assembly with a support platform mountable to a vehicle, which does not have to be removed when a trailer is connected to the vehicle, and which allows the position of the support platform to be adjusted in three directions.

It is also an object of the present invention to provide a kit of parts for building such a step assembly.

These objects are achieved by a step assembly having the features of claim <NUM>, and by a kit of parts having the features of claim <NUM>. Further, particularly advantageous embodiments of the invention are disclosed in the dependent claims.

It should be noted that the individual features listed in the description below could be combined in any technically meaningful way with each other and show further embodiments of the invention. The description of the invention is additionally characterized and specified particularly in connection with the figures.

The present invention discloses a step assembly for removably securing a support platform to a vehicle, comprising: a support system mountable to a trailer hitch or tow bar or tow hitch; a support platform connected with said support system via a plurality of positioning mechanisms comprising: a first positioning mechanism configured for selectively securing and adjusting a height position of the support platform relative to the vehicle; and a second positioning mechanism configured for selectively securing and adjusting a transverse position of the support platform relative to the vehicle; and a third positioning mechanism configured for selectively securing and adjusting a longitudinal position of the support platform relative to the vehicle. The first positioning mechanism itself comprises two subsystems, an up-down displacement mechanism with head and an up-down displacement mechanism with buttons. According to the invention, the up-down displacement mechanism with buttons comprises a hight adjuster pipe support, springs, half bushes, setscrews, a timing shaft and a pipe adapter. The support system may be located at one end (e.g. proximal end) of the step assembly, and the support platform may be located at the other end (e.g. distal end) of the step assembly, and the first, second and third positioning mechanism may be operatively connected between said ends.

It is an advantage of this step assembly that it does not need to be removed when connecting a trailer, thus saving time (of dismounting and remounting), and avoiding that parts of the step assembly need to be temporarily stowed, or may even get lost.

It is a further advantage of this step assembly that the support platform does not need to be rotated to a vertical position, but remains in a horizontal position at all times.

It is a further advantage of this step assembly that the first, second and third position can be chosen independently.

According to a further advantageous embodiment of the present invention, the mounting system comprises a mounting bracket with at least two holes for allowing passage of bolts.

It is an advantage that the mounting bracket can be removed from the vehicle without damaging the vehicle, should that be necessary.

According to a further advantageous embodiment of the present invention, the first positioning mechanism is configured to secure the support platform at a height position selected from a limited group of discrete height positions, e.g. corresponding to a first height position at the same height as the tow bar, a second height position at a floor level of the vehicle, and a third height position below the tow bar.

According to a further advantageous embodiment of the present invention, the second positioning mechanism is configured to secure the support platform at a lateral or transverse position selected from a limited group of discrete transverse positions, e.g. corresponding to a left lateral position substantially aligned with a left side of the vehicle, and a central lateral position substantially aligned with a central position of a rear door, and optionally one or more intermediate lateral positions.

According to a further advantageous embodiment of the present invention, the third positioning mechanism is configured to secure the support platform at a longitudinal position selected from a limited group of discrete longitudinal positions, e.g. corresponding to a frontward position, and a backward position in regard to the vehicle.

According to a further advantageous embodiment of the present invention, the second positioning mechanism comprises a first tubular pipe and a first elongated element arranged inside the first tubular pipe, and a second tubular pipe and a second elongated element movably arranged inside the second tubular pipe, and a third tubular pipe and a third elongated element with a travel shaft portion arranged inside the third tubular pipe, and a fourth tubular pipe and a fourth elongated element with a travel shaft portion arranged inside the fourth tubular pipe.

According to a further advantageous embodiment of the present invention, the third positioning mechanism comprises a pair of two spaced-apart guiding mechanisms, each guiding mechanism comprising a lower guide rail and an upper guide rail slidably arranged thereto. The guiding mechanisms may be oriented substantially horizontally, when the assembly is mounted to the vehicle.

According to another advantageous embodiment of the present invention, the present invention discloses a kit of parts, comprising: the support system, the support platform, the first positioning mechanism, the second positioning mechanism, and the third positioning mechanism.

The mounting bracket is used between the pipe support and the tow bar which are to be connected to the side surface of the tow bar. The pipe support, is placed onto the mounting bracket, has a slot in right in order to allow the inner sliding pin and the moving pipe support to direct sliding on its inner surface easily. While the special rotary shaft head rotating in the pipe support, the special rotary shaft head and the special rotary shaft are pressed on the ball-bearing in the pipe support. The ball-bearings used help reduction the friction. As a result of the special rotary shaft rotating, the moving pipe support enables the linear movement along the slot in the pipe support. The pipe holder, is placed into the moving pipe support, has the hole in order to allow the carrier bolt sliding on its inner surface easily. While the moving pipe support sliding on the pipe holder, the tension spring that used between the inner sliding pin and the pipe holder is pressed sliding the carrier bolt down. When the carrier bolt is moved up by the spring force, the inner sliding pin is placed into the slot on the moving pipe support. Thus, system gets locked, therefore the linear movement of the step platform is not allowed. If desired, up-down displacement system with head can be adjusted the up and down movement of the step platform by turning the special rotary shaft head to the right and left. Firstly, adjustment of the height adjuster pipe support is done with the timing shaft button. The half bush that has the threaded hole is used between the height adjuster pipe support and the moving pipe support which are to be connected. The setscrews are prevented from leaving the place where the height adjuster pipe support and the moving pipe support are inserted. In this case the system is locked with inner and outer slots by contacting between the timing shaft and the height adjuster pipe support, the timing shaft and the moving pipe support. The timing shaft, is placed into the height adjuster pipe support and the moving pipe support, has the slots in order to allow the height adjuster pipe support and the moving pipe support sliding on its outer surface easily. While the timing shaft sliding in the moving pipe support, the height adjuster pipe support and the half bush, the timing shaft button is pressed pushing the spring left. When the timing shaft reaches the height adjuster pipe support until the centring groove where it is located on the height adjuster pipe support, it is moved up by the spring force and placed into the inner groove. Thus, the system gets unlocked, therefore radial rotation movement of the height adjuster pipe support that turns <NUM> degrees is allowed. If desired, the system can be easily locked by stop pushing the locking button of the timing shaft. Finally, adjustment of the pipe adapter is done with the timing shaft button. The half bush that has the threaded hole is used between the height adjuster pipe support and the pipe adapter which are to be connected. The setscrews are prevented from leaving the place where the height adjuster pipe support and the pipe adapter are inserted. In this case the system is locked with inner and outer slots by contacting between the timing shaft and the height adjuster pipe support, the timing shaft and the pipe adapter. The timing shaft, is placed into the height adjuster pipe support and the pipe adapter, has the slots in order to allow the height adjuster pipe support and the pipe adapter sliding on its outer surface easily. The timing shaft button is pressed pushing the spring right while the timing shaft sliding in the pipe adapter and the height adjuster pipe support. When the timing shaft reaches the inner grove where it is located on the pipe adapter, it is moved up by the spring force and placed into the inner hole. Thus, the system gets unlocked, therefore radial rotation movement of the pipe adapter that turns <NUM> degrees is allowed. If desired, the system can be easily locked by stop pushing the timing shaft button. The locking button is used between the pipe adapter and the linear guided pipe receiver which are to be connected. The locking button, is placed onto the button positioner spring, has protrusions in upper and inner in order to allow the linear guided pipe receiver sliding on its surface easily. While the linear guided pipe receiver sliding on the locking button, the locking button is pressed pushing the button positioner springs down. When the locking button reaches the linear guided pipe receiver slots where they are located on the linear guided pipe receiver, it is moved up by the button positioner spring force and placed onto the protrusions. Thus, the system gets unlocked, therefore the linear movement of the linear guided pipe receiver is allowed. If desired, the system can be locked by stop pushing the locking button. The pull handle that fitted with the spring and the special nut inside of adjustable handle has protrusions in upper in order to allow the lower linear guide rail sliding on its surface easily. While the special nut sliding in the adjustable handle, the special nut is pressed pushing the spring down. When the special nut reaches the adjustable handle hole where it is located on the upper linear guide rail, it is moved up by the spring force and placed into the hole. Thus, the system gets unlocked, therefore the linear movement of the upper and the lower linear guide rail is allowed. If desired, the system can be locked by stop pushing the pull handle. The ball-bearings are specially used as to prevent the friction created by the linear movement that occurs between the linear guided pipe receiver and the lower linear guide rail. The lower linear guide rail has chamfered holes to centre the ball-bearings on it. It prevents the ball-bearing from coming out of its place and guides the linear movement of the linear guided pipe receiver. The adjustable handle that attached to the linear guided pipe receiver compress the upper linear guide rail to not move. If desired, the system can be loosened to facilitate the linear movement. As a result, the adjustable step can be easily adjusted to move step by step up and down, right and left and forward and backward by means of the systems.

Further features and advantages of the present invention will become apparent from the following description of a non-limiting embodiment of the invention which will be explained below with reference to the drawing, wherein:.

In the various figures, equivalent elements with respect to their function are always provided with the same reference numerals so that these elements are usually described only once.

In this document, the terms "lateral position" or "transverse position" mean the same.

The present invention relates to a step assembly mountable or mounted to a vehicle, e.g. to a rear end of a commercial vehicle such as e.g. a van. The step assembly can be used to help a person entering or exiting the vehicle via a back door, or can be used to provide easy access to the roof of the vehicle, etc. The step assembly can be attached to the vehicle chassis, e.g. to a tow bar of the vehicle by means of bolts.

The present invention will be explained in more detail referring to a preferred embodiment, but of course the present invention is not limited to this particular example, but only by the claims.

Referring to <FIG> and <FIG>, the present invention provides a step assembly for removably securing a support platform to a vehicle. The step assembly proposed by the present invention comprises: a support system SS1 (e.g. comprising a support bracket <NUM> mountable to a trailer hitch or tow bar or tow hitch, and structurally connected thereto via a plurality of positioning mechanisms), a support platform <NUM> upon which a person can stand. The plurality of positioning mechanisms comprises: a first positioning mechanism SP1A, SP1B configured for selectively securing and adjusting a height position H of the support platform relative to the vehicle; and a second positioning mechanism SP2 configured for selectively securing and adjusting a transverse position T of the support platform relative to the vehicle; and a third positioning mechanism SP3 configured for selectively securing and adjusting a longitudinal position L of the support platform relative to the vehicle.

The first positioning mechanism itself comprise two subsystems, referred to herein as "first up-down displacement mechanism" or "up-down displacement mechanism with head" SP1A, and "second up-down displacement mechanism" or "up-down displacement mechanism with buttons" SP1B.

The step assembly may further comprise a "locking system" and a "clamping system", or the locking system and clamping system may be regarded as being comprised in the second and/or third displacement mechanism.

<FIG> is a copy of <FIG>, without the indication of the plurality of displacement mechanisms or subsystems.

<FIG> shows a schematic high-level view of the various subsystems of the step assembly of <FIG>.

<FIG> show the step assembly of <FIG> mounted to the rear of a vehicle, in a first exemplary 3D position relative to the vehicle ("backwards" in longitudinal direction L of the vehicle, "up" in height direction H, and "right" in transverse direction T).

<FIG> shows a perspective view (seen from above) of the step assembly, showing the support platform <NUM> at substantially the same height as a floor of the vehicle.

<FIG> shows a perspective view (seen from below) of the step assembly showing its backward position.

<FIG> shows a perspective view (seen from behind) of the step assembly showing its upward position.

<FIG> show perspective views (seen from below) of the step assembly to better illustrate its lateral positon (shifted to its rightmost position, corresponding to a central position with respect to the vehicle).

<FIG> show the step assembly of <FIG> mounted to the rear of a vehicle, in a second exemplary 3D position relative to the vehicle ("medium" in longitudinal direction L, "medium" in height direction H, and "left" in transverse direction T). In the example shown, the step assembly is substantially "at tow bar level".

The "up-down displacement system with head" SP1A comprises a special rotary shaft <NUM>, a special rotary shaft head <NUM>, ball-bearings <NUM>, an inner sliding pin <NUM>, an inner fixing pin <NUM>, a setscrew <NUM>, a carrier bolt <NUM>, a tension spring <NUM> and a moving pipe support <NUM>. While the special rotary shaft head <NUM> rotating in the pipe support <NUM>, the special rotary shaft head <NUM> and the special rotary shaft <NUM> are pressed on ball-bearing <NUM> in the pipe support <NUM>. The ball-bearings <NUM> used help reducing the friction. As a result of the special rotary shaft <NUM> rotating, the moving pipe support <NUM> enables the linear movement along the slot in the pipe support <NUM>. The pipe holder <NUM> is placed into the moving pipe support <NUM>, has the hole in order to allow the carrier bolt <NUM> sliding on its inner surface easily. While the moving pipe support <NUM> is sliding on the pipe holder <NUM>, the tension spring <NUM> that is used between inner fixing pin <NUM> and the pipe holder <NUM> is pressed sliding the carrier bolt <NUM> down. When the carrier bolt <NUM> is moved up by the spring <NUM> force, the inner sliding pin <NUM> that the inner fixing pin <NUM> is fitted with the setscrew <NUM> is placed into the slot on the moving pipe support <NUM>. Thus, the system gets locked, therefore the linear movement of the step platform <NUM> is not allowed. If desired, the "up-down displacement system with head" SP1A can be adjusted in the up and down movement of the step platform <NUM> by turning the special rotary shaft head <NUM> to the right and left. As a result, <FIG> show an upper and lower perspective view of the adjustable step at a position below tow bar level. The "up-down displacement system with buttons" SP1B comprises a height adjuster pipe support <NUM>, springs <NUM>, <NUM>, half bushes <NUM>, <NUM>, setscrews <NUM>, <NUM>, a timing shaft <NUM>, <NUM> and a pipe adapter <NUM>. Firstly, adjustment of the height adjuster pipe support <NUM> is done with the locking button <NUM>.

<FIG> shows a cross-sectional side view of the "up-down displacement with buttons" system SP1B in a locked configuration. The half bush <NUM> that has the threaded hole <NUM> is used between the height adjuster pipe support <NUM> and the moving pipe support <NUM> which are to be connected. The setscrews <NUM> are prevented from leaving the place where the height adjuster pipe support <NUM> and the moving pipe support <NUM> are inserted. In this case the system is locked with inner and outer slots by contacting between the timing shaft <NUM> and the height adjuster pipe support <NUM>, the timing shaft <NUM> and the moving pipe support <NUM>. The timing shaft <NUM> is placed into the height adjuster pipe support <NUM> and the moving pipe support <NUM>, has the travel slot <NUM> in order to allow the height adjuster pipe support <NUM> and the moving pipe support <NUM> sliding on its outer surface easily. While the timing shaft <NUM> sliding in the moving pipe support <NUM>, the height adjuster pipe support <NUM> and the half bush <NUM>, the timing shaft <NUM> button is pressed pushing the spring <NUM> left. When the timing shaft <NUM> reaches the height adjuster pipe support <NUM> until the centering groove <NUM> where it is located on the height adjuster pipe support <NUM>, it is moved up by the spring <NUM> force and placed into the hole. Thus, the system gets unlocked, therefore radial rotation movement of the height adjuster pipe support <NUM> that turns <NUM> degrees is allowed.

<FIG> shows a cross-sectional side view of the "up-down displacement with buttons" system SP1B in an unlocked configuration. If desired, the system can be easily locked by stop pushing the locking button <NUM> of the timing shaft <NUM>. Finally, adjustment of the pipe adapter <NUM> is done with the timing shaft <NUM> button.

As mentioned above <FIG> shows a cross-sectional side view of the "up-down displacement with buttons" SP1B system in a locked configuration. The half bush <NUM> that has the threaded hole <NUM> is used between the height adjuster pipe support <NUM> and the pipe adapter <NUM> which are to be connected. The setscrews <NUM> are prevented from leaving the place where the height adjuster pipe support <NUM> and the pipe adapter <NUM> are inserted. In this case the system is locked by contacting between the timing shaft <NUM> and the height adjuster pipe support <NUM>, the timing shaft <NUM> and the pipe adapter <NUM>. The timing shaft <NUM> is placed into the height adjuster pipe support <NUM> and the pipe adapter <NUM>, has the slots in order to allow the height adjuster pipe support <NUM> and the pipe adapter <NUM> sliding on its outer surface easily. While the timing shaft <NUM> sliding in the pipe adapter <NUM>, the height adjuster pipe support <NUM> and the half bush <NUM>, the timing shaft <NUM> button is pressed pushing the spring <NUM> right. When the timing shaft <NUM> reaches the inner groove <NUM> where it is located on the pipe adapter <NUM>, it is moved up by the spring <NUM> force and placed into the inner groove <NUM>. Thus, the system gets unlocked, therefore radial rotation movement of the pipe adapter <NUM> that turns <NUM> degrees is allowed.

<FIG> shows a cross-sectional side view of the up-down displacement system with buttons in an unlocked configuration. If desired, the system can be easily locked by stop pushing the timing shaft <NUM> button. As a result, <FIG> show an upper and lower perspective view of the adjustable step substantially at platform floor level.

<FIG> shows a perspective view (seen from above) of the step assembly showing the support platform <NUM> at a height position slightly lower than a floor of the vehicle.

<FIG> shows a perspective view (seen from below) of the step assembly showing its medium position in longitudinal direction.

<FIG> shows a perspective view (seen from behind) of the step assembly showing its medium height position.

<FIG> show perspective views (seen from below) of the step assembly to better illustrate its lateral positon (shifted to its leftmost position, corresponding to a laterally outward position with respect to the vehicle).

<FIG> show the step assembly of <FIG> mounted to the rear of a vehicle, in a third exemplary 3D position relative to the vehicle ("forward" in longitudinal direction L, "down in height direction H, and "right" in transverse direction T).

<FIG> shows a perspective view (seen from above) of the step assembly showing the support platform <NUM> at a height position considerably lower than a floor of the vehicle.

<FIG> shows a perspective view (seen from below) of the step assembly showing its forward position in longitudinal direction.

<FIG> shows a perspective view (seen from behind) of the step assembly showing its downward height position.

<FIG> show perspective views (seen from below) of the step assembly to better illustrate its lateral positon (shifted to its rightmost position, corresponding to a laterally central position with respect to the vehicle).

<FIG> show an exploded view of a subsystem of the step assembly of <FIG>, referred to herein as the "support system" SS1.

The support system SS1 comprises a mounting bracket <NUM>, a bolt <NUM>, a pipe support <NUM>, the setscrew <NUM>, a pipe holder <NUM> and a fixing bolt <NUM>. The support system SS1 carries the entire load of the adjustable step. The mounting bracket <NUM> is used between the pipe support <NUM> and the tow bar which may be connected to a side surface of the tow bar. The pipe support <NUM> is placed onto the mounting bracket <NUM>, has a slot in order to allow the inner sliding pin <NUM> and the moving pipe support <NUM> to direct sliding on its inner surface easily.

<FIG> illustrates parts of the "first positioning mechanism" also referred to herein as "up-down displacement system with head" SP1A.

<FIG> show parts of the mechanism shown in <FIG> in more detail.

<FIG> illustrates another part of the "first positioning mechanism".

<FIG> shows a cross-sectional side view of the "up-down displacement system with buttons" SP1B in a locked configuration.

<FIG> and <FIG> show a cross-sectional side view of the "up-down displacement system with buttons" SP1B in an unlocked configuration.

<FIG> illustrate the "second positioning mechanism", also referred to herein as "left-right displacement system" SP2, as can be used in the step assembly of <FIG>.

The left-right displacement system SP2 comprises a locking button <NUM>, a button positioner spring <NUM>, a button positioner <NUM>, a fixing setscrew <NUM> and a linear guided pipe receiver <NUM> (see also <FIG>). The locking button <NUM> is used between the pipe adapter <NUM> and the linear guided pipe receiver <NUM> which are to be connected. The locking button <NUM>, which is placed onto the button positioner spring <NUM>, has protrusions in order to allow the linear guided pipe receiver <NUM> sliding on its surface easily. While the linear guided pipe receiver <NUM> sliding on the locking button <NUM>, the locking button <NUM> is pressed pushing the button positioner springs <NUM> down. When the locking button <NUM> reaches the linear guided pipe receiver <NUM> slots, which are located on the linear guided pipe receiver <NUM>, it is moved up by the button positioner spring <NUM> force and placed onto the protrusions. Thus, the system gets unlocked, therefore linear movement of the linear guided pipe receiver <NUM> is allowed. If desired, the system can be locked by stop pushing the locking button <NUM>.

<FIG> illustrate the "third positioning mechanism", also referred to as "front-back displacement system" SP3 as can be used in the step assembly of <FIG>.

The front-back displacement system SP3 comprises an upper linear guide rail <NUM>, a lower linear guide rail <NUM>, ball-bearing <NUM>, a bolt <NUM>, the step platform <NUM>, and optionally also a reflective tape <NUM>, a parking sensor <NUM>, a wiring harness <NUM> and fixings with cable tie <NUM> (see also <FIG>). The ball-bearings <NUM> are specially used as to prevent the friction created by the linear movement that occurs between the linear guided pipe receiver <NUM> and the lower linear guide rail <NUM>. The lower linear guide rail <NUM> has the chamfered holes <NUM> to center the ball-bearings <NUM> on it. It prevents the ball-bearing <NUM> from coming out of its place and guides the linear movement of the linear guided pipe receiver <NUM>.

<FIG> illustrate a subsystem referred to herein as "locking system and clamping system", as can be used in the step assembly of <FIG>.

<FIG> show a cross-sectional side view of the "locking system" and the "clamping system" in a locked and an unlocked configuration, respectively.

The locking system comprises a special nut <NUM>, a spring <NUM>, an adjustable handle <NUM> and a pull handle <NUM>. The pull handle <NUM> fits with the spring <NUM> and the special nut <NUM> inside of adjustable handle <NUM> has protrusions in order to allow the lower linear guide rail <NUM> sliding on its surface easily. While the special nut <NUM> sliding in the adjustable handle <NUM>, the special nut <NUM> is pressed pushing the spring <NUM> down. When the special nut <NUM> reaches the stopping hole <NUM> which it is located on the upper linear guide rail <NUM>, it moves up by the spring <NUM> force and is placed into the the inner groove <NUM>. Thus, the system gets unlocked, therefore the linear movement of the upper <NUM> and the lower linear guide rail <NUM> is allowed. If desired, the system can be locked by stop pushing the pull handle <NUM>.

The clamping system comprises adjustable handles <NUM> and a linear guided pipe receiver <NUM>. The adjustable handle <NUM> that attached to the linear guided pipe receiver <NUM> compress the upper linear guide rail <NUM> to not move. If desired, the system can be loosened to facilitate the linear movement.

The adjustable step may be mounted to the vehicle in the following manner:
The mounting bracket <NUM> has a prismatic <NUM> and a cylindrical protrusion <NUM> where pipe support <NUM> is mounted, two fixing holes <NUM><NUM> where the bolt <NUM> and the setscrew <NUM> is mounted.

The pipe support <NUM> has a fixing hole <NUM> where the mounting bracket <NUM>, a back threaded hole <NUM> where the pipe holder <NUM> and a front cylindrical hole <NUM> where the special rotary shaft <NUM> is mounted. It has a holding sphere <NUM> and a lower stiffener <NUM> carrying and supporting the entire system's load. It has a prismatic protrusion <NUM> where the pipe holder <NUM> is mounted. It has an inner groove <NUM> where the special rotary shaft head <NUM> and the ball-bearing <NUM> are placed and a side groove <NUM> providing the special rotary shaft head <NUM> ease of use. It has an upper groove <NUM>, a lower groove <NUM> and a back groove <NUM> where the pipe holder <NUM> is mounted. It has an upper side groove <NUM> and a lower side groove <NUM> where the moving pipe support <NUM> is to be placed, providing easy mounting of the inner sliding pin <NUM>. It has a lower slot <NUM> where prismatic protrusion <NUM> of the mounting bracket <NUM> are to be placed and the pipe support <NUM> not to rotate on the mounting bracket <NUM>. It also has a side slot <NUM> that the inner sliding pin <NUM> and the moving pipe support <NUM> are to be placed providing the inner sliding pin <NUM> and the moving pipe support <NUM> travelling along itself while being rotated.

The special rotary shaft head <NUM> has an inner slot <NUM> where the special rotary shaft <NUM> is mounted. It has double knurls <NUM> that provide easy rotation of the special rotary shaft head <NUM>. It has ball-bearing grooves <NUM> where the ball-bearings <NUM> to be placed in order to prevent the friction created by rotation of the movement that occurs between the pipe support <NUM> and the special rotary shaft head <NUM>, the pipe support <NUM> and the special rotary shaft <NUM>, the pipe holder <NUM> and the special rotary shaft <NUM>. It has a rotating groove <NUM> where an L-shaped tool is placed for easy rotating. It also has a side groove <NUM> where the knurls not to be created on its cylindrical surface.

The special rotary shaft <NUM> has a trimmed protrusion <NUM> which is placed into the inner slot <NUM> of the special rotary shaft head <NUM>. It has a front slot <NUM> and a back slot <NUM> where the ball-bearings <NUM> are to be placed in order to prevent the friction created by rotation of the movement. It is also a special thread <NUM> which carries the entire system's load and controls the movement of the up-down displacement system.

The inner sliding pin <NUM> that has a sliding hole <NUM> through which the special rotary shaft <NUM> in the pipe support <NUM> passes is mounted into the pipe support <NUM>. It has a supporting protrusion <NUM> where the moving pipe support <NUM> and the inner fixing pin <NUM> to be placed. The supporting protrusion <NUM> helps to limit the movement of the inner fixing pin <NUM>. It has an upper groove <NUM> and a lower groove <NUM> where the side slot to be placed. The upper groove <NUM> and the lower groove <NUM> direct the linear movement of the inner sliding pin <NUM> in the side slot <NUM>. It has a fixing protrusion <NUM> where the moving pipe support <NUM> to be placed for limiting the movement of the inner sliding pin <NUM> in the lower slot <NUM> and being fixed to the inner fixing pin <NUM>. It has a fixing hole <NUM> where the setscrew <NUM> is mounted for fixing the position of the inner fixing pin <NUM>.

The inner fixing pin <NUM> has a threaded hole <NUM> where the setscrew <NUM>, and has a fixing threaded hole <NUM> where the carrier bolt <NUM> and has a fixing hole <NUM> where the setscrew <NUM> is mounted. It has a pressing groove <NUM> where the tension spring <NUM> to be placed. It provides necessary tension force to the inner fixing pin <NUM>. It has a fixing groove <NUM> where the inner sliding pin <NUM> to be placed.

The setscrew <NUM> is mounted into the threaded hole <NUM> in order to fix the inner sliding pin <NUM> on the inner fixing pin <NUM>.

The tension spring <NUM> is placed into the inner fixing pin <NUM> and the pipe holder <NUM>.

The moving pipe support <NUM> is placed onto the half bush <NUM> and has a threaded hole <NUM> where the special rotary shaft <NUM> is mounted. It turns the rotational movement into the linear movement while making contact with each other. It has a lower groove <NUM> and an upper groove <NUM> where the side slot <NUM> of the pipe support <NUM> is mounted. It has a fitting hole <NUM> where the setscrew <NUM> is mounted in order to connect the inner sliding pin and the inner fixing pin to be easily inserted into the moving pipe support. It has a pushing hole <NUM> where the timing shaft <NUM> to be placed for easy pushing of the locking button. It has a fixing hole <NUM> where setscrew <NUM> is mounted in order to fix the position of the moving pipe support <NUM>. It has a sliding cutter shaft <NUM> where the timing shaft <NUM> is mounted. It directs the right-left movement of the timing shaft. It also has an upper slot <NUM> and a lower slot <NUM> where the pipe holder <NUM> and the inner sliding pin <NUM> to be placed in order to limit the linear movement of the inner sliding pin <NUM>.

The ball-bearings <NUM> are placed into the back slot <NUM>. Then the pipe holder <NUM> has a back protrusion <NUM> mounted into the back groove <NUM>. It keeps the special rotary shaft <NUM> and the ball-bearing <NUM> in their place. It has a front groove <NUM> where the tension spring <NUM> to be placed. It has a back groove <NUM> where the carrier bolt <NUM> is placed. It allows connecting the inner fixing pin and prevents the carrier bolt <NUM> from coming out of its place. It has a sliding hole <NUM> where the carrier bolt <NUM> is mounted. It has an upper protrusion <NUM> and a lower protrusion <NUM> where the pipe support <NUM> is mounted. It also has an upper chamfered hole <NUM> and a lower chamfered hole <NUM> where the fixing bolt <NUM> is mounted.

The fixing bolt <NUM> is mounted into the back threaded hole <NUM>.

The carrier bolt <NUM> is placed into the sliding hole <NUM>.

The timing shaft <NUM> has a locking button <NUM> where is placed into the pushing hole <NUM>. It is a specially designed locking button <NUM> as to go left and right easily through the pushing hole <NUM> in the moving pipe support <NUM>. It has a long timing shaft <NUM> where to be placed into the moving pipe support and a short timing shaft <NUM> where to be placed into the height adjuster pipe support <NUM>. It has a travel slot <NUM> where the setscrew <NUM> to be placed. It provides necessary travel to the timing shaft <NUM> to go right and left while pressing and depressing it. It moves from right to left and from left to right with the effect of the locking button <NUM>. It allows the height adjuster pipe support <NUM> to rotate when moving from right to left. It allows the height adjuster pipe support <NUM> to fix when moving from left to right. It has a centering groove <NUM> where the spring <NUM> to be placed. It is used to center and direct the spring <NUM> while pressing and depressing the locking button <NUM>.

The half bush <NUM> is placed onto the timing shaft <NUM>, into the moving pipe support <NUM> and the height adjuster pipe support <NUM>. It has a holding feature <NUM> that the height adjuster pipe support <NUM> and the moving pipe support <NUM> to be placed and prevented from sliding out of the place. It has a positioning chamfer <NUM> that allows sliding of the height adjuster pipe support <NUM> and the moving pipe support <NUM> easily. It has a threaded hole <NUM> where the setscrew <NUM> is mounted. It has a half hole <NUM> where the timing shaft <NUM> to be placed.

The spring <NUM> is placed into the centering groove <NUM>.

The height adjuster pipe support <NUM> is placed onto the half bush <NUM>. It has a pushing hole <NUM> that made for easy pushing of the locking button <NUM> of the timing shaft <NUM>. It has a fixing hole <NUM> where the setscrew <NUM> is mounted. It has a sliding cutter shaft <NUM> where is placed onto the timing shaft <NUM> and directs the right-left movement of the timing shaft <NUM>. It has an inner groove <NUM> where the locking button <NUM> is placed. It has a supporting fillet <NUM> that used to increase the resistance against incoming loads during rotation. It has a thin protrusion <NUM> that used to increase the resistance against incoming loads during rotation. It has an adjusting slot <NUM> where the setscrew <NUM> is mounted, restricts the rotational movement of the height adjuster pipe support <NUM> and prevents it from moving out. It has a rotating cutter shaft <NUM> allowing the rotation of the height adjuster pipe support <NUM> when the timing shaft <NUM> in the height adjuster pipe support <NUM> moves from right to left and prevents the rotation of the height adjuster pipe support <NUM> when it moves from left to right. It also has a centering groove <NUM> that used to center and direct the spring <NUM> while pressing and depressing the locking button <NUM> of the timing shaft <NUM>.

The setscrew <NUM> is mounted into the threaded hole <NUM> of the half bush <NUM>.

The timing shaft <NUM> is placed into the height adjuster pipe support <NUM> and the pipe adapter <NUM>. It has a side button <NUM> where to be placed as to go left and right easily through the pushing hole <NUM> in the height adjuster pipe support <NUM>. It has a long timing shaft <NUM> where to be placed into the height adjuster pipe support <NUM>. It has a travel slot <NUM> where the setscrew <NUM> to be placed in order to provide necessary travel to the timing shaft <NUM> to go right and left while pressing and depressing it. It has a short timing shaft <NUM> where to be placed into the pipe adapter <NUM> and moves from left to right and from right to left with the effect of the side button <NUM>. It also allows the pipe adapter <NUM> to rotate and fix when moving from left to right.

The half bush <NUM> is placed onto the timing shaft <NUM> into the height adjuster pipe support <NUM> and the pipe adapter <NUM>. It has a holding feature <NUM> preventing the height adjuster pipe support <NUM> and the pipe adapter <NUM> from sliding out of the place. It has a positioning chamfer <NUM> that allows sliding of the height adjuster pipe support <NUM> and the pipe adapter <NUM> easily. It also has a threaded hole <NUM> where the setscrew <NUM> and a half hole <NUM> where the timing shaft <NUM> to be placed.

The spring <NUM> is placed into the inner groove <NUM>.

The pipe adapter <NUM> is placed onto the timing shaft <NUM> and into the linear guided pipe receiver <NUM>. It has a sliding slot <NUM> where the setscrew <NUM> to be placed. It is used to control and provide necessary travel to locking button to go up and down while pressing and depressing it. It has an adjusting slot <NUM> where the setscrew <NUM> to be placed in order to restricts the rotational movement of the pipe adapter and prevents it from moving out. It has a directing protrusion <NUM> used for the linear guided pipe receiver <NUM> not to turn on the pipe adapter <NUM>. It has a fixing hole <NUM> where the button positioner <NUM> is mounted. It has an inner groove <NUM> where the button positioner <NUM>, the locking button <NUM> and the button positioner spring <NUM> to be positioned. It has a rotating cutter shaft <NUM> that allows the rotation of the pipe adapter <NUM> when the timing shaft <NUM> in the pipe adapter <NUM> moves from left to right and prevents the rotation of the timing shaft <NUM> when it moves from right to left. It also has an inner groove <NUM> where the spring is mounted.

The button positioner <NUM> is placed into the inner groove <NUM>. It has a controlling protrusion <NUM> where the fixing setscrew <NUM> to be positioned. It has an inner threaded hole <NUM> where the fixing setscrew <NUM> is mounted. It has a combining chamfer <NUM> that enables the joining of separate elements made by welding. It has a supporting chamfer <NUM> that enables the joining of separate button positioner elements made by welding. It has an inner protrusion <NUM> that the linear guided pipe receiver <NUM> is mounted and designed for the locking button <NUM> going through the locking slot <NUM>. It has a left thin cover <NUM> and a right thin cover <NUM> that allows the button positioner <NUM> to fit into the pipe adapter <NUM>. It also has outer chamfer <NUM> that made so that sharp corners do not harm the user during installation.

The button positioner spring <NUM> is placed into the inner protrusion <NUM>.

The locking button <NUM> is placed into the inner groove <NUM>. It has a locking protrusion <NUM> where is mounted as to go through the locking slot <NUM> in the linear guided pipe receiver <NUM>. It has a sliding hole <NUM> that allows centering the locking button <NUM> moving up and down. It has a centering protrusion <NUM> that allows centering the locking button <NUM> moving up and down. It also has a combining chamfer <NUM> that enables the joining of separate elements made by welding.

The fixing setscrew <NUM> is mounted into the inner threaded hole <NUM>.

The linear guided pipe receiver <NUM> is mounted onto the pipe adapter <NUM>. It has a locking slot <NUM> that controls the locking button <NUM> pass through inside. It has a sliding slot <NUM> that located outside the directing protrusion <NUM> of the pipe adapter <NUM> and controls the linear movement of the linear guided pipe receiver <NUM>. It has a side protrusion <NUM> that used to guide and stabilize the movements of the lower <NUM> and the upper linear guide rails <NUM>. It has a supporting protrusion <NUM> that helps to fix by tightening the lower <NUM> and the upper linear guide rail <NUM> with the adjustable handle <NUM>. It has a threaded hole <NUM> where the adjustable handle is mounted and it prevents the vibrations that occur on the lower <NUM> and the upper linear guide rails <NUM> compressing it. It has a front groove <NUM> and a back groove <NUM> where the bolts <NUM> of the step platform <NUM> to be placed during the forward and the backward movement of the linear guided pipe receiver <NUM>. It has an outer fillet <NUM> that made to prevent the user during the rotation of the adjustable handle <NUM>. It has an outer chamfer <NUM> and an outer fillet <NUM> that made to prevent the user from harms of sharp edges.

The pull handle <NUM> is mounted into the controller hole <NUM>. It has a threaded protrusion <NUM> that prevents the special nut <NUM> from coming out of its place.

The adjustable handle <NUM> is mounted into the threaded hole <NUM>. It has a threaded protrusion <NUM> where the adjustable handle <NUM> is mounted and allows the locking system to be fixed to the linear guided pipe receiver <NUM>. It has an adjusting groove <NUM> that is used to easily tighten the lower linear guide rail <NUM> by hand. It has a controller hole <NUM> that allows movement of the pull handle <NUM>. It has an inner fillet <NUM> that is made to prevent the interference with the adjustable handle <NUM> during the up and down movement of the pull handle <NUM>. It also has an inner groove <NUM> where the spring <NUM> to be placed and the movement of the pull handle <NUM> is kept under control.

The spring <NUM> is placed onto the pull handle <NUM>.

The special nut <NUM> is mounted onto the pull handle <NUM>. It has threaded holes <NUM> where the pull handle <NUM> is mounted, then rotating holes <NUM> that can be easily rotated and tightened.

The lower linear guide rail <NUM> are mounted onto the bolts <NUM>. It has a stopping hole <NUM> that the special nut <NUM> is mounted provides locking by allowing the special nut <NUM> pass through inside. It has a fixing protrusion <NUM> that designed to support between the lower linear guide rail <NUM> and the upper linear guide rail <NUM> when it is connected with bolt <NUM> on the step platform <NUM>. It has a chamfered hole <NUM> where the ball-bearings <NUM> to be located. It has a chamfered hole <NUM> and an inner chamfered hole <NUM> where the bolt <NUM> is mounted. It has a fixing groove <NUM> that positioned on the lower linear guide rail <NUM> provides locking by allowing the special nut <NUM> pass through inside. It also has an outer chamfer <NUM> and an outer fillet <NUM> that made to prevent the user from harms of sharp edges.

The ball-bearings <NUM> are placed into the chamfered hole <NUM>.

The upper linear guide rail <NUM> has an inner hole <NUM> where the bolt <NUM> is mounted. It has an outer chamfer <NUM> and an outer fillet <NUM> that made to prevent the user from harms of sharp edges.

Step platform <NUM> is mounted onto the lower linear guide rail <NUM> and the upper linear guide rail <NUM>.

Bolt <NUM> is mounted into the step platform <NUM>.

Firstly, the mounting bracket <NUM> is connected to the side surface of the tow bar with the bolt <NUM>. The pipe support <NUM> is inserted into the mounting bracket <NUM>. It goes into the mounting bracket <NUM> until the end of the cylindrical protrusion <NUM>. The prismatic protrusion <NUM> prevents longitudinal and radial movement. When it reaches, the setscrew <NUM> is mounted into the fixing hole <NUM>.

Then, the ball-bearings <NUM> are inserted into the ball-bearing grooves <NUM>. It goes into the ball-bearing grooves <NUM> until an inner groove <NUM> reaches the special rotary shaft head <NUM>. When it reaches, the ball-bearings <NUM> are inserted into the front slot <NUM>. It goes into the front slot <NUM> until the inner groove <NUM> reaches the special rotary shaft <NUM>.

Then, the inner sliding pin <NUM> is inserted into the side slot <NUM>. It goes into the side slot <NUM> until the end of the inner groove <NUM> and the moving pipe support <NUM> is inserted into the side slot <NUM> by moving it on rotating the special rotary shaft <NUM>. It goes into the side slot <NUM> until the inner groove <NUM> reaches the inner sliding pin <NUM>.

Then, the ball-bearings <NUM> are inserted into the back slot <NUM>. It goes into the back slot <NUM> until the back groove <NUM> reaches the pipe holder <NUM>. When it reaches, the fixing bolts <NUM> are mounted in the bottom and top of the back threaded hole <NUM>. The fixing bolts <NUM> go in the bottom and top of the back threaded hole <NUM> until the upper groove <NUM> and the lower groove <NUM> reaches the pipe holder <NUM>.

Then, the moving pipe support <NUM> is inserted onto the supporting protrusion <NUM>. It goes onto the supporting protrusion <NUM> until the fixing protrusion <NUM> reaches the inner fixing pin <NUM>. When it reaches, the setscrew <NUM> is inserted into the threaded hole <NUM>. It goes onto the threaded hole <NUM> until the outer surface of inner fixing pin <NUM>.

Then, the tension spring <NUM> is inserted between the front groove <NUM> and the fixing threaded hole <NUM>. It goes between the front groove <NUM> and the fixing threaded hole <NUM> until the sliding hole <NUM> reaches the carrier bolt <NUM>. When it reaches, the carrier bolt <NUM> is inserted into fixing threaded hole <NUM>. It goes into the fixing threaded hole <NUM> until the end of the fixing threaded hole <NUM>.

Then, the two half bushes <NUM> as a whole are inserted onto the travel shaft <NUM>. The two half bushes <NUM> and the timing shaft <NUM> are inserted into the inner groove <NUM> and the pushing hole <NUM>. The two half bushes <NUM> and the timing shaft <NUM> go into the inner groove <NUM> and the pushing hole <NUM> until the beginning of the sliding cutter shaft <NUM> and the end of the pushing hole <NUM> reach the places. When the two half bushes <NUM> and the timing shaft <NUM> reach, the setscrew <NUM> is mounted into the threaded hole <NUM>. The spring <NUM> is inserted into the centering groove <NUM>. The height adjuster pipe support <NUM> is inserted onto other side of the two half bushes <NUM> as a whole. The other sides of the two half bushes <NUM> go into the inner groove <NUM> until the beginning of the rotating cutter shaft <NUM> reaches the place. When the other sides of the two half bushes <NUM> reach, the setscrew <NUM> is mounted into the threaded hole <NUM>. As a result, the spring <NUM> is placed between the centering groove <NUM> and the centering groove <NUM>.

Then, the two half bushes <NUM> as a whole are inserted onto the travel shaft <NUM>. The two half bushes <NUM> and the timing shaft <NUM> are inserted into the inner groove <NUM> and the pushing hole <NUM>. The two half bushes <NUM> and the timing shaft <NUM> go into the inner groove <NUM> and the pushing hole <NUM> until the beginning of the sliding cutter shaft <NUM> and the end of the pushing hole <NUM> reach the places. When the two half bushes <NUM> and the timing shaft <NUM> reach, the setscrew <NUM> is mounted into the threaded hole <NUM>. The spring <NUM> is inserted into the inner groove <NUM>. The pipe adapter <NUM> is inserted onto other side of the two half bushes <NUM> as a whole. The other sides of the two half bushes <NUM> go into the inner groove <NUM> until the beginning of the rotating cutter shaft <NUM> reaches the place. When the other sides of the two half bushes <NUM> reach, the setscrew <NUM> is mounted into the threaded hole <NUM>. As a result, the spring <NUM> is placed between the inner groove <NUM> and the side surface of the timing shaft <NUM>.

Then, the button positioner spring <NUM> is inserted onto the button positioner <NUM>. When the button positioner spring <NUM> goes onto the inner protrusion <NUM> until the supporting chamfer <NUM> reaches, the locking button <NUM> is inserted into the button positioner spring <NUM>. The sliding hole <NUM> of the locking button <NUM> goes onto the inner protrusion <NUM> until the cylindrical outer surface of the button positioner <NUM> and the cylindrical outer surface of the locking button <NUM> reach to be concentric. When it reaches, they are inserted into the inner groove <NUM> of the pipe adapter <NUM>. They go into the inner groove <NUM> until the inner threaded hole <NUM> reaches the fixing hole <NUM>. When it reaches, the fixing setscrew <NUM> is mounted into the inner threaded hole <NUM>. It must be inserted all the way length into the fixing hole <NUM> because the linear guided pipe receiver <NUM> slides on the directing protrusion <NUM> is that prevents radial movement.

Then, the linear guided pipe receiver <NUM> is inserted onto the pipe adapter <NUM>. It goes onto the pipe adapter <NUM> until the sliding slot <NUM> reaches the locking protrusion <NUM>. The locking protrusion <NUM> is that prevents linear movement. When the locking button <NUM> is manually pressed into the sliding slot <NUM> by the spring <NUM> force, it reaches. When it reaches, the locking button <NUM> is depressed into the sliding slot <NUM> by the spring <NUM> force. As a result, the locking protrusion <NUM> of the locking button <NUM> is placed into the locking slot <NUM> of the linear guided pipe receiver <NUM>.

Then, the adjustable handle <NUM> is inserted into the pull handle <NUM>. The spring <NUM> is inserted onto the pull handle <NUM> and inserted into the adjustable handle <NUM>. The special nut <NUM> is mounted onto the pull handle <NUM>. It goes into the pull handle <NUM> until the threaded protrusion <NUM>. Those that are mounted onto the pull handle <NUM> are mounted into the threaded hole <NUM> by means of the adjustable handle <NUM> until the inner surface of the side protrusion <NUM> reaches the lower linear guide rail <NUM>.

Then, the ball-bearings <NUM> are inserted onto the lower linear guide rail <NUM>. They go into the chamfered hole <NUM>. The upper linear guide rail <NUM> is inserted onto the ball-bearings <NUM>. The upper linear guide rail <NUM> goes onto the ball-bearings <NUM> until the chamfered hole <NUM> and the inner hole <NUM> reach to be concentric. When they reach, they are inserted into the linear guided pipe receiver <NUM>. Before they go into the inner surface of the side protrusion <NUM>, the pull handle <NUM> is pulled down. As a result, the special nut <NUM> that mounted onto the pull handle <NUM> goes into the inner groove <NUM> until the side surface of the special nut <NUM> reaches the inner surface of the side protrusion <NUM>. When it reaches, they the upper linear guide rail <NUM>, the ball-bearings <NUM> and the lower linear guide rail <NUM> go into the inner surface of the side protrusion <NUM> until the cylindrical outer surface of the special nut <NUM> and the desired stopping hole <NUM> reach to be concentric. When it reaches, the pull handle <NUM> pulling down is stopped. The special nut <NUM> that mounted onto the pull handle <NUM> goes into the stopping hole <NUM> with the effect of the spring <NUM>.

Then, the step platform <NUM> is inserted onto the linear guided pipe receiver <NUM>.

Optionally, after the bolt <NUM> is mounted into the step platform, the fixings with cable tie <NUM> are mounted into the step platform <NUM>. Then, the parking sensors <NUM> are mounted into the step platform <NUM> and the wiring harness <NUM> is mounted into the fixing with cable tie <NUM>. Finally, the reflective tape <NUM> is placed onto the side surfaces of the step platform <NUM>. Thus, connection is completed. Of course, the order of some of the steps may be changed.

Claim 1:
A step assembly for removably securing a support platform to a vehicle, comprising:
- a support system (SS1) mountable to a trailer hitch or tow bar or tow hitch;
- a support platform (<NUM>) connected with said support system via a plurality of positioning mechanisms (SP1A, SP1B; SP2; SP3),
wherein the plurality of positioning mechanisms comprises:
- a first positioning mechanism (SP1A, SP1B) configured for selectively securing and adjusting a height position (H) of the support platform (<NUM>) relative to the vehicle; and
- a second positioning mechanism (SP2) configured for selectively securing and adjusting a transverse position (T) of the support platform (<NUM>) relative to the vehicle, and
- a third positioning mechanism (SP3) configured for selectively securing and adjusting a longitudinal position (L) of the support platform (<NUM>) relative to the vehicle, wherein the first positioning mechanism itself comprises two subsystems, an up-down displacement mechanism with head (SP1A) and an up-down displacement mechanism with buttons (SP1B)
characterised in, that
the up-down displacement mechanism with buttons (SP1B) comprises a height adjuster pipe support (<NUM>), springs (<NUM>,<NUM>), half bushes (<NUM>,<NUM>), setscrews (<NUM>,<NUM>), a timing shaft (<NUM>,<NUM>) and a pipe adapter (<NUM>).