Retractable tailgate step assembly system

Abstract

A stowable tailgate step assembly system includes a frame having two frame arms connected to each other, the frame arms adapted to be mounted in a vehicle tailgate in a longitudinal direction. A sliding module releasably latched to the frame includes a step assembly and two longitudinal carrier arms translating relative to the frame arms. The step assembly includes: two sliding arms translating relative to the carrier arm; and a first step portion and at least one additional step portion, the first step portion and the at least one additional step portion being pivotally connected by at least one link to facilitate synchronous rotation of the step portions. Control means are provided for controlling the rotation of the step during translation of the carrier arm from the stowed position to the extended position. Deployment means are also provided for controlling rotation of the step between the extended position and the deployed position. A locking latch rotationally connected with the at least one carrier arm engages the at least one associated frame arm to prevent translation of the carrier arm relative to the associated frame arm when the step assembly is in the extended position.

Description

Technical Field

[0001] The present invention relates to the field of motor vehicles and, in particular, to a step system for a pickup truck. Background Art

[0002] Pickup trucks may be provided with step features to allow easier entry and exit from the truck bed when the tailgate is open. For safety and to reduce wear, it is advantageous to stow any such steps when they are not in use. Various devices have been used to stow and deploy such steps. Summary of the invention

[0003] A retractable tailgate step assembly has been developed. In one aspect of the invention, a retractable tailgate step assembly system includes a frame having two interconnected frame arms adapted to be longitudinally mounted in a vehicle tailgate. The frame is adapted to receive a slide module releasably latched to the frame. The slide module includes: two longitudinal load-bearing arms that translate relative to the frame arms; and a step assembly. The step assembly includes: two slide arms that translate relative to the load-bearing arms; and a first step portion and at least one additional step portion, the first step portion and the at least one additional step portion being pivotally connected by at least one link to facilitate synchronous rotation of the step portions. A control device is provided for controlling rotation of the step portion during translation of the load-bearing arm from a stowed position to an extended position. A deployment device is also provided for controlling rotation of the step portion between the extended position and the deployed position. A lock-out latch is rotationally connected to at least one load-bearing arm, and when the step assembly is in the extended position, the lock-out latch engages at least one associated frame arm to prevent translation of the at least one load-bearing arm relative to the associated frame arm. The locking latch disengages from the associated frame arm when the slide arm associated with the associated frame arm translates into at least one of the carrier arms to initiate stowage of the step assembly into the frame.

[0004] In a further aspect of the invention, the control means comprises a guide pin mounted to one of the first step and the at least one additional step, the guide pin engaging a shaped guide slot adjacent an end of at least one of the carrier arms.

[0005] In another aspect of the present invention, the control device includes: a first guide pin, the first guide pin is mounted to the first step portion; a guide bracket, the guide bracket is mounted to one of the carrier arms, and the guide bracket includes a shaped guide groove for receiving the first guide pin. When the first guide pin is located outside the shaped guide groove, the first guide pin is restricted from vertical movement via the motion control surface portion of the carrier arm and the corresponding sliding arm.

[0006] In a further aspect of the invention, the control means comprises a roller mounted to one of the first step and the at least one additional step, the roller translating in a rotational manner on a ramp mounted to at least one of the carrier arms.

[0007] In another aspect of the present invention, the unfolding device includes: the step portion, which is pivotally connected to the sliding arm by a pivot pin, the step portion is coplanar with the sliding arm before unfolding, but the step portion is rotated relative to the sliding arm to be parallel to the vehicle body when unfolded, and the step portions are pivotally connected to each other by at least one connecting rod to ensure synchronous and parallel rotation of the step portions; at least one guide pin, which is installed at the lateral side of at least one of the step portions, and the guide pin contacts the motion control surface portion on the load-bearing arm to keep the step portion coplanar with the sliding arm during unfolding of the step assembly; a guide bracket, which includes a guide groove positioned adjacent to the rear end of the load-bearing arm so as to receive the guide pin in a reversible manner, and the guide groove is formed to apply rotation to the step portion on which the guide pin is installed.

[0008] In a further aspect of the invention, a locking latch releasably engages a locking pin mounted to the step assembly to prevent the step assembly from extending relative to the carrier arm until the slide module is clear of the frame.

[0009] In a further aspect of the invention, the slide module is releasably latched to the frame by at least one assembly latch, which is released by means of a latch release handle.

[0010] In another aspect of the present invention, when the tailgate step assembly is latched via at least one assembly latch, the tailgate step assembly is in the stowed position; when the assembly latch is released and the sliding module is translated to the limit relative to the frame, the tailgate step assembly is in the extended position; and when the step portion is rotated to the use position, the tailgate step assembly is in the deployed position.

[0011] In another alternative aspect of the present invention, the latch release handle is connected to at least one lateral arm, which rotates at least one locking rod located between at least one of the sliding arms and the load-bearing arm associated with the sliding arm, and the locking rod is provided with a spring-loaded pawl, which is suitable for locking into a locking groove in at least one of the load-bearing arms and the frame arm associated with the load-bearing arm.

[0012] In a further aspect of the invention, the load stop is rotatably mounted to the upward face portion of the step assembly.

[0013] In a further aspect of the present invention, the load stopper is embedded in the first step portion when not in use.

[0014] In another aspect of the invention, when a load stop rotatably mounted to an upward face of a step assembly is rotated perpendicular to the step assembly, the load stop is locked in place by a spring-loaded pawl engaging a locking slot in at least one of the load arms and a frame arm associated with the load arm.

[0015] In further aspects of the invention, a spring-loaded ratchet coupled to the load stop, one of the load arms, and a slide module associated with the load arm allows the load stop to be moved in small increments into close proximity with the cargo, and releasing the ratchet allows the load stop to be moved back far enough from the cargo to be stored in the step assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a perspective view of a retractable step assembly system installed in a schematically shown tailgate.

[0017] Figure 2 is a perspective view of a stowable step assembly system in a disassembled state.

[0018] Figure 3 is a perspective view of a frame of a stowable step assembly system.

[0019] Figure 4 is a perspective view of a slide module of a stowable step assembly system with the step assembly partially extended.

[0020] Figure 5 is a partial perspective view of a stowable step assembly system, wherein the step assembly is stowed.

[0021] Figure 6 is a perspective view of a stowable step assembly system with a carrier arm extending from a frame and a step assembly partially extending from the carrier arm.

[0022] Figure 7 It is an exploded perspective view of a sliding module of a retractable step assembly system.

[0023] Figure 8 is a partial perspective view of the locking latch.

[0024] Fig. 9 is another partial perspective view of the locking latch showing the locking slot and the guide slot.

[0025] Fig.10 is a partial perspective view of the frame, the sliding module and the locking latch, wherein the sliding module is translated rearward.

[0026] Fig.11is a partial perspective view of a separated stowable step assembly system with the locking latch in the Fig.10 orientation.

[0027] Fig.12 is a partial perspective view of the locking latch translated to the locked position, wherein the sliding module is moved rearward.

[0028] Fig.13 is a partial perspective view of at least one additional step portion mounted to the slide arm.

[0029] Fig.14 It is a partial perspective view of a separated step assembly, wherein the step portion is parallel to the sliding arm.

[0030] Fig.15 It is a partial stereoscopic view of the first step portion in the step assembly.

[0031] Fig.16 is a perspective view of a separated step assembly, wherein the step portion is parallel to the slide arm.

[0032] Fig.17 is a perspective view of the separated step assembly with the steps unfolded for use.

[0033] Fig.18 It is a three-dimensional, partially transparent image of the locking groove, guide groove, locking pin and guide pin.

[0034] Fig.19 is a perspective view of a slide module of a stowable step assembly system with the slide arm partially extended.

[0035] Fig. 20 It is a partial three-dimensional, partially transparent view of a sliding module, wherein the guide pin is about to enter the guide groove.

[0036] Fig.21 is a perspective view of a separated sliding module, wherein the step portion is partially unfolded.

[0037] Fig. 22 It is a partially transparent perspective view of a portion of the sliding module, wherein the guide pin is completely positioned in the guide groove.

[0038] Fig.23 is a perspective view of a stowable step assembly system installed in a schematically shown tailgate with the step portion partially deployed.

[0039] Fig.24 is a perspective view of a stowable step assembly system installed in a schematically shown tailgate with the step portion fully deployed.

[0040] Fig.25is a perspective view of the separated step assembly, wherein the step portion is partially unfolded when the step assembly is returned to be parallel with the carrier arm.

[0041] Fig.26 is a partial perspective view of an alternative latch system showing the guide arm, frame arm, spring loaded pawl, and locking slot.

[0042] Fig. 27 is a perspective view of a separated slide module with an alternative latching system, with the mid-step partially unfolded.

[0043] Fig.28 is a partially perspective, partially transparent view of a slide module with an alternative latching system, wherein the guide pins are fully positioned in the guide slots.

[0044] Fig.29 is a perspective view of a disassembled stowable step assembly system with the carrier arm extended and the step assembly partially extended.

[0045] Fig.30 is another perspective view of the separated stowable step assembly system with the carrier arm extended, the step assembly partially extended, and showing the locking latch.

[0046] Fig.31 is a fragmentary perspective view of a locking latch in contact with a locking pin and rotated out of a locked position.

[0047] Fig.32 yes Fig.31 , where the locking latch is rotated further below the longitudinal contact surface of the frame arm.

[0048] Fig.33 is a perspective view of a retractable step assembly system installed in a schematically illustrated tailgate, with the step assembly fully retracted.

[0049] Fig.34 is a perspective view of a disassembled slide module with an alternative latch system, wherein the step assembly is partially extended.

[0050] Fig.35 yes Fig.34 , where the lateral arm rotates as part of an alternative latch system.

[0051] Fig.36 is a cross-sectional perspective view showing a locking bar and pawl of an alternative latch system, wherein the latch pawl is locked.

[0052] Fig.37 yes Fig.36, which shows the rotation direction of the locking bar and pawl, wherein the latch pawl is unlocked.

[0053] Fig.38A is a perspective view of a stowable step assembly system installed in a tailgate shown realistically and including a stowed load stop.

[0054] Fig.38B yes Fig.38A with a partially deployed load stop.

[0055] Fig.39A yes Fig.38A View of the load stop with the load stop fully deployed.

[0056] Fig.39B yes Fig.39A FIG. 1 is a view of a load stop having a block for movement of cargo.

[0057] Fig.40 is a perspective, partially transparent, partial view of an alternative control device with rollers and ramps, with the step partially rotated open.

[0058] Fig.41 yes Fig.40 A view of a portion of the step portion being partially rotated back to a position for stowage.

[0059] Fig.42 is a different perspective partial view of an alternative control device, wherein the step portion is rotated to be parallel with the slide arm for stowage.

[0060] The embodiments, examples and alternatives in the preceding paragraphs, claims or the following description and drawings include any aspects or corresponding individual features of the embodiments, examples and alternatives, and the embodiments, examples and alternatives and any aspects or corresponding individual features thereof can be used independently or in any combination. Unless the features are incompatible, the features described in conjunction with one embodiment apply to all embodiments. DETAILED DESCRIPTION

[0061] The retractable tailgate step assembly 1 of the present invention is most suitable for a configuration having two step portions, but a single step portion or more than two step portions may also be used. Figures 1 to 7 , the frame 3 is mounted in a vehicle tailgate 5. As the tailgate may generally be mounted to a pickup truck or other suitable vehicle, a truck is not shown. Figure 1 and Figure 638 and 39. The frame 3 is shown schematically in FIG. 39 and is shown in a more realistic manner in FIG. 38. The frame 3 is seated between the front and rear surfaces of the tailgate 5, or between the inner face 7 and the outer face 9, defined when the tailgate 5 is in a closed upright position. The frame 3 is provided with two frame arms 11, 13, which are oriented from top to bottom within the tailgate 5 when the tailgate 5 is closed. When the tailgate 5 is opened 90 degrees and parallel to the floor of the truck bed, the frame arms 11, 13 are oriented in the fore and aft direction of the vehicle. As described herein, when the retractable tailgate step assembly 1 is in use, the tailgate 5 is parallel to the floor of the truck bed. The frame arms 11, 13 are preferably connected by transverse connectors 15, 17 to form a stable frame structure. In one embodiment, a bracket 19 with a striker 21 is attached to the rear of the frame arms 11, 13 for assembly latching 23. In alternative embodiments, latching may be performed in multiple positions without the use of a striker.

[0062] The sliding module 25, which may also be referred to as a sliding assembly, is releasably attached to the frame 3. The sliding module 25 includes a rear crossbar 27 that includes a latch release handle 29. In one embodiment, movement of the latch release handle 29 from a rest position releases an assembly latch 23 located at a distal end of the crossbar 27. The assembly latch 23 releasably engages with a fork 21 on the frame arms 11, 13. In further embodiments, a plurality of latch positions are provided, including a latch position in which the crossbar 27 is latched to the frame 3, as further described and illustrated herein.

[0063] The crossbeam 27 is connected to two sliding arms 31, which may be tubular, and the sliding arms 31 are adjacent to the distal end of the crossbeam 27. The sliding arms 31 translate relative to two carrying arms 33, which may also be referred to as guide arms, and which are also oriented in the front-to-back direction. Two steps are pivotally mounted between the sliding arms 31, the two steps being a first step 35 and at least one additional step 37, which is a second step in this configuration. However, any step may be designated as a first step. Although two steps are preferred, other numbers of steps may also be used, such as three or four steps. The crossbeam 27, the sliding arms 31 and the steps 35, 37 constitute a step assembly 39. The step assembly 39 and the carrying arms 33 constitute a sliding module 25. The sliding module 25 translates relative to the frame arms 11, 13. When the assembly latch 23 or the replacement latch is released using the latch release handle 29, the sliding module 25 can be pulled out horizontally from the frame 3. This action allows the steps 35, 37 to be deployed, with the step assembly 39 positioned at an angle between the load arm 33 parallel to the truck bed and the ground. Lifting and pushing the crossbar 27 using the latch release handle 29 or other means causes the step assembly 39 to return horizontally toward the interior of the truck bed until the slide module 25 is again latched to the frame 3. With the slide module 25 stowed, substantially only the crossbar 27 is exposed.

[0064] The step assembly 39 also translates relative to the carrier arm 33. Figures 8 to 12 , at least one locking latch 41 prevents the step assembly 39 from translating relative to the carrier arm 33 until the sliding module 25 is pulled rearward relative to the frame arms 11, 13 and freed from the restraint provided by the frame arms 11, 13. This includes moving the step assembly 39 from the stowed position to the extended position. Preferably, a locking latch 41 is provided on each lateral side of the sliding module 25, but a single locking latch 41 may also be used. The locking latch 41 ensures that the step portions 35, 37 are not deployed prematurely. The locking latch 41 is pivotally mounted to the carrier arm 33 and is spring-loaded. When the sliding module 25 is stowed and when the sliding module 25 is extended rearward to the limit, a locking pin 43 mounted adjacent to the front end of the carrier arm 33 engages with the rear portion of the locking latch 41. Preferably, the locking pin 43 is releasably restrained by a locking latch slot 45 located in the locking latch 41. When a single locking latch 41 is used, a single locking pin 43 is used. When the slide module 25 is retracted and when the slide module 25 is extended rearward to the extended position, the front end of the locking latch 41 contacts the frame arms 11, 13 in a sliding manner. This contact allows the locking latch elastic member 47 of the locking latch 41 to remain biased and the locking pin 43 to engage with the rear portion of the locking latch 41 during the backward extension of the slide module 25.

[0065] When the sliding module 25 is fully extended rearward to the limit, the front end of the locking latch 41 passes the rear end of the frame arms 11, 13 and no longer contacts the longitudinal contact surface 49 of the frame arms 11, 13, thereby allowing the locking latch 41 to rotate under the bias of the locking latch elastic member 47. The rotation of the locking latch 41 releases the locking pin 43 from the locking latch slot 45 in the locking latch 41. As shown, this rotation can be clockwise. With the locking pin 43 thus released, the step assembly 39 is free to translate rearward relative to the carrier arm 33. The front end of the rotated locking latch 41 is now located at the rear of the frame arms 11, 13. The forward movement of the sliding module 25 from this position causes the front end of the rotated locking latch 41 to contact the rear end of the frame arms 11, 13. This contact of the rotated locking latch 41 with the rear end of the frame arms 11, 13 prevents the carrier arm 33 from sliding relative to the frame arms 11, 13 until the locking pin 43 on the step assembly 39 enters the locking latch slot 45 in the rear portion of the locking latch 41 again. This biases the locking latch spring 47 again, which rotates the front end of the locking latch 41. This rotation causes the front end of the locking latch 41 to drop below the top of the frame arms 11, 13. As shown, this rotation can be counterclockwise. When the sliding module 25 moves toward the stowed position, the front end of the locking latch 41 contacts the frame arms 11, 13 in a sliding manner again.

[0066] The rear ends of the frame arms 11, 13 are provided with pivot brackets 51. The pivot brackets 51 include pivot bracket slots 53 that engage with bracket pins 55 mounted to the front ends of the carrier arms 33. These bracket pins 55 and pivot bracket slots 53 prevent the carrier arms 33 from further rearward translation when the step assembly 39 is deployed.

[0067] refer to Figures 13 to 33 , the steps 35, 37 are pivotally connected to the sliding arm 31 by a pivot pin 57. The steps 35, 37 are coplanar with the sliding arm 31 before deployment, but rotate relative to the sliding arm 31 to be generally parallel to the truck bed and the ground when deployed. The steps 35, 37 are pivotally connected to each other by connecting rods 59. Preferably, a connecting rod 59 is provided at each lateral side of each step 35, 37. These connecting rods 59 ensure that the steps 35, 37 always rotate synchronously and in parallel.

[0068] A control device is also provided. Guide pins 61 are mounted at the lateral sides of at least one of the steps 35, 37, typically the guide pins 61 are mounted at the lateral sides of the first step 35, as will be described below. These guide pins 61 contact the motion control surface portion 63 on the carrier arm 33, which keeps the steps 35, 37 in a coplanar relationship with the slide arm 31 when the step assembly 39 is extended for deployment. A guide bracket 65 is provided at the rear end of the carrier arm 33, the guide bracket 65 includes a guide slot 67, and the guide pin 61 enters the guide slot 67 to permit deployment. The guide slot 67 is shaped to impose rotation on the first step 35 on which the guide pin 61 is mounted. The shaping typically includes arcing to facilitate rotation. The additional step or second step 37 is forced to rotate in the same manner as the first step 35 due to the connecting rod 59 connecting the steps 35, 37. An array of two or more steps connected in this way operates in a similar manner.

[0069] When the step assembly 39 is fully deployed, the step assembly 39 can be pivoted downward to the deployed position, with the step portions 35, 37 oriented for use. When the step assembly 39 is rotated back to be parallel with the tailgate 5, the guide pin 61 moves correspondingly in the guide slot 67, which returns the step portions 35, 37 to be parallel with the truck bed and coplanar with the sliding arm 31.

[0070] You can use Figure 40 to Figure 42 An alternative control device is shown. The control device includes a roller mounted to one of the first step and at least one additional step, the roller translating in a rotational manner on a ramp-shaped member mounted to at least one of the carrier arms. The step control link 85 is rotationally connected to the second step 37 at one end and is rotationally connected to the sliding arm 31 at the other end. The sliding arm pivot pin 87 that connects the sliding arm 31 and the second step 37 in a rotational manner and the step pivot pin 89 that connects the step control link 85 and the second step 37 in a rotational manner provide a rotation axis for the second step 37. A guide roller 91 is rotationally mounted along the step control link 85. When the sliding arm 31 is pushed into the carrier arm 33 associated with the sliding arm 31, the guide roller 91 contacts the ramp-shaped member 93 or the guide cam. When the guide roller 91 rolls along the guide cam 93, the second step 37 rotates to a horizontal orientation relative to the sliding arm 31. In contrast, when the slide arm 31 extends away from the carrier arm 33, the guide roller 91 moves downward along the guide cam or ramp 93 to rotate the second step 37 away from the horizontal direction relative to the slide arm 31. The slide arm pivot pin 87 is guided in the slide arm pivot pin slot 95 to accommodate the geometric relationship between the slide arm pivot pin 87 and the step portion pivot pin 89 when the second step portion 37 rotates.

[0071] As mentioned above, alternative latching devices may be used. Figure 34 to Figure 37 In a further embodiment, the latch release handle 29 is connected to at least one transverse arm 69, which rotates at least one longitudinal locking lever 71, which is located between at least one of the sliding arms 31 and the carrier arm 33 associated with the sliding arm 31. The locking lever 71 is provided with a spring-loaded pawl 73, which is adapted to lock into a locking groove 75 located in at least one of the carrier arms 33 and its associated frame arm 11, 13. The spring-loaded pawl 73 can be mounted to the locking lever 71 in a fixed manner in the circumferential direction, or in other ways. When the spring loaded pawl 73 is appropriately shaped, such as the pawl 73 extending significantly outwardly from the locking rod 71 in one axis and very little in an orthogonal axis, when the spring loaded pawl 73 is spring biased, one or more outwardly protruding portions of the spring loaded pawl 73 may fall into one or more of a plurality of locking slots 75 provided, the locking slots 75 being located at intervals along the length of at least one of the sliding arms 31 and its associated carrier arm 33. Any number of locking slots 75 may be selected to achieve a desired number of locking positions.

[0072] refer to FIG. 38A to FIG. 39B Another beneficial feature that can be added to the stowable tailgate step assembly 1 is a load stop 79. The load stop helps to keep certain cargo 81 in the cargo box of the pickup truck. For example, when transporting plywood or drywall that may extend beyond the cargo box, the tailgate 5 must be lowered from its normal upright closed position. With the tailgate 5 lowered to be parallel with the cargo box, the cargo box is effectively extended by the tailgate 5. However, without the closed tailgate 5, the cargo 81 is now unrestricted from moving rearward. Therefore, the load stop 79 is preferably rotatably mounted on the upwardly directed face of the step assembly 39, such as on the step portion 37 closest to the rear cross member 27. One or more hinges that connect the step assembly 39 and the load stop 79 in a rotatable manner can be used to permit such rotation. The hinge can be located at the rear end of the step assembly 39, for example, the hinge can be located on the step portion 37. The load stopper 79 may be a solid plate, or may be formed as, for example, an arched rod or tube. Various shapes and forms of the load stopper 79 are possible.

[0073] Preferably, the load stop 79 can be mounted flush with the upward face of the step assembly 39, which faces upward when the tailgate 5 is opened to be parallel to the cargo box. The recess 83 located in the upward face of the step portion 37 facilitates this flush mounting. This allows the cargo 81 to be more easily loaded and unloaded on the open tailgate 5 without causing physical obstruction. Whether the tailgate 5 is open or not, this flush mounting of the load stop 79 is also more preferred for visual appearance and safety when the load stop 79 is not used. With the cargo 81 loaded, the load stop 79 can be rotated to be upright. A simple latch can be used to hold the load stop 79 in the upright position of the load stop 79 and release the load stop 79 to be stowed in a manner flush with the step assembly 39. Alternatively, the load stop 79 may be connected to a mechanism of locking rods 71 ​​and spring-loaded pawls 73, such that rotation of at least one spring-loaded pawl 73 into the locking slot 75 may lock the load stop 79 in place. Alternatively, a ratchet (not shown) may be associated with the slide module 25 to allow the load stop 79 to move in small increments to abut against the cargo 81, and to allow the load stop 79 to move back far enough from the cargo 81 to be stowed again in the step assembly 39 when released.

[0074] Other technical means for producing the same results in the context of the present invention will be apparent to those skilled in the art.

[0075] Although a particular component arrangement has been disclosed in the illustrated embodiments, other arrangements will also benefit from the present invention.

[0076] Although exemplary embodiments have been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of the claims. Therefore, the following claims should be studied to determine their true scope and content.

Claims

1. A retractable tailgate step assembly system, the retractable tailgate step assembly system comprising: a frame having two frame arms connected to each other, the frame arms being adapted to be mounted in a vehicle tailgate in a longitudinal direction; The frame is adapted to receive a sliding module, the sliding module being releasably latched to the frame; The sliding module includes two longitudinal bearing arms that translate relative to the frame arms; The sliding module also includes a step assembly; The step assembly includes two sliding arms that translate relative to the carrier arm; The step assembly further includes a first step portion and at least one additional step portion, wherein the first step portion and at least one additional step portion are pivotally connected by at least one connecting rod to facilitate synchronous rotation of the step portions; a control device for controlling the rotation of the step portion during translation of the carrying arm between the stowed position and the extended position; an unfolding device, the unfolding device being used to control the rotation of the step portion between the extended position and the unfolded position; a locking latch rotationally connected to at least one of the carrier arms, the locking latch engaging an associated frame arm when the step assembly is in the extended position to prevent translation of at least one of the carrier arms relative to the associated frame arm; wherein the locking latch disengages from the associated frame arm when the associated sliding arm translates into at least one of the carrier arms to initiate stowage of the step assembly into the frame.

2. The stowable tailgate step assembly system according to claim 1, wherein: The control means comprises a guide pin mounted to one of the first step and at least one of the additional steps, the guide pin engaging with a shaped guide slot adjacent an end of at least one of the carrier arms.

3. The stowable tailgate step assembly system according to claim 1, wherein: The control device comprises: a first guide pin mounted to the first step portion; a guide bracket mounted to one of the carrier arms, the guide bracket including a shaped guide slot for receiving the first guide pin; Wherein, when the first guide pin is located outside the shaped guide slot, the first guide pin is restrained from vertical movement via the motion control surface portion of the carrier arm and the corresponding slide arm.

4. The stowable tailgate step assembly system according to claim 1, wherein: The control means comprises a roller mounted to one of the first step and at least one of the additional steps, the roller translating in rotation on a ramp mounted to at least one of the carrier arms.

5. The stowable tailgate step assembly system according to claim 1, wherein: The deployment device includes: the step portion, which is pivotally connected to the sliding arm by a pivot pin, the step portion being coplanar with the sliding arm before deployment, but the step portion is rotated relative to the sliding arm to be parallel to the vehicle box when deployed, and the step portions are pivotally connected to each other by at least one connecting rod to ensure synchronous and parallel rotation of the step portions; at least one guide pin, which is installed at the lateral side of at least one of the step portions, the guide pin contacts the motion control surface portion on the carrying arm to keep the step portion coplanar with the sliding arm during deployment of the step assembly; a guide bracket, the guide bracket including a guide groove positioned adjacent to the rear end of the carrying arm so as to receive the guide pin in a reversible manner, the guide groove being shaped to apply rotation to the step portion on which the guide pin is installed.

6. The stowable tailgate step assembly system according to claim 1, wherein: The locking latch releasably engages a locking pin mounted to the step assembly to prevent the step assembly from extending relative to the carrier arm until the slide module is clear of the frame.

7. The stowable tailgate step assembly system according to claim 1, wherein: The slide module is releasably latched to the frame by at least one assembly latch which is released by means of a latch release handle.

8. The stowable tailgate step assembly system according to claim 1, wherein: When the tailgate step assembly is latched via at least one assembly latch, the tailgate step assembly is in a stowed position; when the assembly latch is released and the sliding module is translated to a limit relative to the frame, the tailgate step assembly is in an extended position; and when the step portion is rotated from the extended position to a use position, the tailgate step assembly is in a deployed position.

9. The stowable tailgate step assembly system according to claim 7, wherein: The latch release handle is connected to at least one lateral arm, which allows at least one locking rod located between at least one of the sliding arms and a load-bearing arm associated with the sliding arm to rotate, and the locking rod is provided with a spring-loaded pawl, which is suitable for locking into a locking groove located in at least one of the load-bearing arms and a frame arm associated with the load-bearing arm.

10. The stowable tailgate step assembly system of claim 1 further comprising a load stop rotatably mounted in an upward face portion of the step assembly.

11. The stowable tailgate step assembly system according to claim 10, wherein: The load stopper is embedded in the first step portion when not in use.

12. The stowable tailgate step assembly system according to claim 9, wherein: When a load stop rotatably mounted in an upward face portion of the step assembly is rotated perpendicular to the step assembly, the load stop is locked in place by the spring-loaded pawl engaging with a locking slot in at least one of the carrier arms and a frame arm associated with the carrier arm.

13. The stowable tailgate step assembly system according to any one of claims 10, 11 and 12, wherein: A spring-loaded ratchet connected to the load stop, one of the load arms, and a slide module associated with the load arm allows the load stop to be moved in small increments into close proximity with cargo, and releasing the ratchet allows the load stop to be moved back far enough from the cargo to be stored in the step assembly.

14. The stowable tailgate step assembly system according to claim 4, wherein: The ramp includes a guide cam.

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