Description of the Related Art It is commonly known to add a running board or similar fixed stepping assist to the side of a motor vehicle, especially to a vehicle with a relatively high ground clearance.

However, these fixed running boards and other stepping assists have had several drawbacks. First, a fixed running board is often too high to act as a practical stepping assist and is therefore not very effective in reducing the initial step height for the vehicle user. In addition, when using a relatively high running board, the user is likely to hit his or her head while climbing into the vehicle cab. Furthermore, a fixed running board often extends a significant distance from the side of the vehicle, and can be a source of dirt or grime that rubs onto the user's pants or other clothing as the user steps out of the vehicle onto the ground surface. Such a fixed running board is also frequently struck when the owner of an adjacent parked vehicle opens his door. Finally, a fixed running board or step reduces the ground clearance of a vehicle, and can often be damaged or torn off entirely when the vehicle is used for offroad driving.

Accordingly, a vehicle step which overcomes the above-stated problems is desired.

Summary of the Invention In accordance with one embodiment, a retractable step for use with a vehicle comprises a stepping member having a stepping deck, a first arm, a second arm, a motor and a stop. The first arm has a first end pivotally attached to the vehicle, and a second end pivotally attached to the stepping member. The second arm also has a first end pivotally attached to the vehicle, and a second end pivotally attached to the stepping member. The motor is drivingly connected to the first arm such that a rotation of the motor causes

rotation of the first arm about its first end and moves the stepping member from a retracted position to an extended position, or vice versa. The stop is located within the range of motion of the second arm such that the second arm bears against the stop when the stepping member is in the extended position. The first and second arms are situated such that the first arm is loaded in compression and the second arm is loaded in tension when the stepping member is in the extended position and a load is placed upon it.

In accordance with another embodiment, a retractable vehicle step assist comprises a rigid frame, a forward planar linkage pivotably connected to the frame along a forward upper connection width, and a rearward planar linkage pivotably connected to the frame along a rearward upper connection width. The retractable vehicle step further comprises a rigid step member having a stepping deck. The step member is pivotably connected to the forward planar linkage along a forward lower connection width, and is pivotably connected to the rearward planar linkage along a rearward lower connection width and on a side of the forward planar linkage opposite the stepping deck. The stepping deck is substantially wider than any of the forward upper connection width, the rearward upper connection width, the forward lower connection width, and the rearward lower connection width.

In accordance with yet another embodiment a retractable vehicle step assist for use with a vehicle having two adjacent doors through which persons may enter the vehicle, comprises a rigid frame, a step member having a stepping deck, and at least two rigid arms connecting the step member to the frame and allowing the step member to move between a retracted position near the frame to a deployed position downward and away from the frame. The stepping deck is of sufficient width to provide a step for persons desiring to enter either of the doors.

In accordance with still another embodiment, a retractable vehicle step assist for use with a vehicle having two adjacent doors through which persons may enter the vehicle, comprises a rigid frame and a step member having a stepping deck. The retractable step assist further comprises at least two rigid arms connecting the step member to the frame and allowing the step member to move between a retracted position near the frame to a deployed position downward and away from the frame. The stepping deck extends in front of each of the doors when in the deployed position.

In accordance with still another embodiment, a retractable vehicle step assist comprises a rigid frame, a step member having a stepping deck, and at least two rigid arms

connecting the step member to the frame and allowing the step member to move between a retracted position near the frame to a deployed position downward and away from the frame. The stepping deck is substantially wider than the frame.

In accordance with still another embodiment, a retractable vehicle step assist comprises a rigid frame, a step member having a stepping deck, and a forward rigid arm and a rearward rigid arm connecting the step member to the frame and allowing the step member to move between a retracted position near the frame to a deployed position downward and away from the frame. The step member is pivotably connected to the rearward rigid arm at a rearward pivotable connection and the step member rotates downward about the rearward pivotable connection as the step member moves to the deployed position.

In accordance with still another embodiment, a retractable vehicle step assist comprises a rigid frame, a step member having a stepping deck, and at least two rigid arms connecting the step member to the frame and allowing the step member to move between a retracted position near the frame to a deployed position downward and away from the frame. The stepping member further comprises a support bracket rigidly connected to the stepping deck and connected to the arms opposite the stepping deck. The support bracket is oriented at an angle to the stepping deck.

In accordance with still another embodiment, a method of improving access to a vehicle through a door of the vehicle, comprises attaching a rigid frame to the vehicle, and connecting a stepping member having a stepping deck to the frame via at least two rigid arms. This is done so that the stepping member is moveable between a retracted position near the frame to a deployed position wherein the stepping deck is situated along the side of the vehicle below the door. In the method the stepping deck is substantially wider than the frame.

In accordance with another embodiment, there is provided a retractable step for a vehicle having a body with a lower edge. The step comprises a rigid frame configured for attachment to the vehicle so that substantially all of the frame is behind the lower edge of the body, a rotatable linkage connected to the frame, and a step member connected to the rotatable linkage opposite the frame. The step member has a deployed position, and a retracted position in which the step member and the rotatable linkage are located behind the lower edge of the body.

In accordance with another embodiment, there is provided a vehicle which comprises a body having a lower edge and a retractable step assist attached to the vehicle.

The retractable step assist comprises a rigid frame attached to the vehicle so that substantially all of the frame is behind the lower edge of the body, a rotatable linkage connected to the frame, and a step member connected to the rotatable linkage opposite the frame. The step member has a deployed position, and a retracted position in which the step member and the rotatable linkage. are located behind the lower edge of the body.

In accordance with another embodiment, there is provided a retractable vehicle step assist configured for attachment to a vehicle. The step assist comprises a rigid frame, a step member having a stepping deck, and a rotatable linkage. The linkage connects the step member to the frame and allows the step member to move between a deployed position and a retracted position in which an upper surface of the stepping deck is substantially concealed from the view of an adult standing outside the vehicle.

In accordance with another embodiment, there is provided a retractable step for a vehicle having a body with an under panel. The step comprises a rigid frame configured for attachment to the vehicle, a rotatable linkage connected to the frame and a step member connected to the rotatable linkage opposite the frame. The step member has a stepping deck with an upper surface. The step member has a deployed position, and a retracted position in which the upper surface of the stepping deck is substantially flush with the under panel.

In accordance with another embodiment, there is provided a retractable vehicle step assist configured for attachment to a vehicle. The step assist comprises a rigid frame, a step member having a stepping deck, and a rotatable linkage. The linkage connects the step member to the frame and allows the step member to move between a deployed position and a retracted position in which only a forward edge of the stepping deck is visible to an adult standing outside the vehicle.

In accordance with another embodiment, there is provided a retractable step for a vehicle having an underbody with a substantially vertical outer surface. The step comprises a rigid frame configured for attachment to the vehicle, a linkage connected to the frame, and a step member connected to the linkage opposite the frame. The step member has a deployed position, and a retracted position in which a forward edge of the step member is spaced rearward from the outer surface of the underbody by at least 1.5 inches.

In accordance with another embodiment, there is provided a retractable step for a vehicle having a body with a lower edge. The step comprises a rotatable linkage connectable to the vehicle, and a step member connected to the rotatable linkage. The step member has a deployed position, and a retracted position in which the step member and the rotatable linkage are located behind the lower edge of the body.

In accordance with another embodiment, there is provided a vehicle, comprising a body having a lower edge, and a retractable step assist attached to the vehicle. The retractable step assist comprises a rotatable linkage connected to the vehicle, and a step member connected to the rotatable linkage. The step member has a deployed position, and a retracted position in which the step member and the rotatable linkage are located behind the lower edge of the body.

In accordance with another embodiment, there is provided a retractable step for a vehicle having an underbody with a substantially vertical outer surface. The step comprises a linkage connectable to the vehicle, and a step member connected to the linkage. The step member has a deployed position, and a retracted position in which a forward edge of the step member is spaced rearward from the outer surface of the underbody by at least 1.5 inches.

In accordance with another embodiment, a retractable step for a vehicle comprises a forward linkage having an upper portion connectable to the vehicle so as to be rotatable about a first axis, and a rearward linkage having an upper portion connectable to the vehicle so as to be rotatable about a second axis. The second axis is located rearward of the first axis, and the first and second axes are oriented generally parallel to a longitudinal axis of the vehicle. The step further comprises a step member connected to the forward and rearward linkage so as to be movable between a retracted position and an extended position.

At least a portion of the rearward linkage extends forward of the first axis when the step member is in the extended position.

In accordance with another embodiment, a retractable step for a vehicle comprises a first arm having an upper portion rotatably fixable with respect to an underside of the vehicle so as to be rotatable about a first axis of rotation oriented generally parallel to an adjacent lower edge of the vehicle. The step further comprises a second arm having an upper portion rotatably fixable with respect to an underside of the vehicle so as to be rotatable about a second axis of rotation oriented generally parallel to an

adjacent lower edge of the vehicle and located rearward of the first axis. The step further comprises a step member connected to the first and second arms so as to be movable between a retracted position near the underside of the vehicle and an extended position remote from the underside. At least a portion of the second arm extends forward of the first axis when the step member is in the extended position.

In accordance with another embodiment, a retractable step for a vehicle comprises a first arm having an upper portion rotatably fixable with respect to an underside of the vehicle so as to be rotatable about a first axis of rotation, and a second arm having an upper portion rotatably fixable with respect to an underside of the vehicle so as to be rotatable about a second axis of rotation. The step further comprises a step member connected to the first and second arms so as to be movable between a retracted position under the vehicle and an extended position extending outward from the vehicle.

At least one of the first arm and the second arm further comprises a stop member which extends toward the other of the first arm and the second arm and contacts the other arm when the step member is in the extended position.

In accordance with another embodiment, a retractable step for a vehicle comprises a first arm having an upper portion rotatably mountable to an underside of the vehicle so as to be rotatable about a first axis of rotation oriented generally parallel to an adjacent lower edge of the vehicle, and a second arm having an upper portion rotatably mountable to an underside of the vehicle so as to be rotatable about a second axis of rotation oriented generally parallel to an adjacent lower edge of the vehicle and located rearward of the first axis. The step further comprises a step member connected to the first and second arms so as to be movable between a retracted position at least substantially entirely under the vehicle and an extended position extending outward from the vehicle. The step member comprises a stepping deck defining an upper surface thereof and a connection region which is located rearward and upward from the stepping deck when the step member is in the extended position, and wherein at least one of the first and second arms is connected to the step member at the connection region. It is believed that this overall arrangement facilitates storing the step out of sight, while enabling the final deployment movement of the step to include a downward rotational component about a third axis at the lower end of the first arm. It is believed that this arrangement facilitates self-energizing of the step. That is,

when a load is placed on the step, the step continues its downward rotational movement somewhat, so that the load is not carried by any motor driving the step.

In accordance with another embodiment, a retractable step for a vehicle comprises a first arm having an upper portion rotatably mountable to an underside of the vehicle so as to be rotatable about a first axis of rotation, and a second arm having an upper portion rotatably mountable to an underside of the vehicle so as to be rotatable about a second axis of rotation oriented generally parallel to the first axis. The step further comprises a step member connected to the first and second arms so as to be movable between a retracted position at least substantially entirely under the vehicle and an extended position extending outward from the vehicle. The first arm is connected to the step member so as to be rotatable about a third axis and the second arm is connected to the step member so as to be rotatable about a fourth axis, the third and fourth axes being oriented generally parallel to the first and second axes. Desirably, the distance between the third and fourth axes is less than 6 inches, more desirably less than 4 inches and, most desirably, less than 2 inches.

The axes are arranged according to a first aspect ratio, which comprises a ratio of (1) the distance between the third axis and the fourth axis and (2) the distance between the first axis and the third axis, and the first aspect ratio is less than. 4 and, preferably, less than. 3.

It is believed that these distances and ratios facilitate the ability to permit the step to be stored in a small envelope out of sight and to yet be deployable to the desired deployment position.

In accordance with another embodiment, a retractable vehicle step assist comprises a rigid frame, a forward planar linkage pivotably connected to the frame along a forward upper connection width, and a rearward planar linkage pivotably connected to the frame along a rearward upper connection width. The step further comprises a rigid step member having a stepping deck. The step member is pivotably connected to the forward planar linkage along a forward lower connection width, and pivotably connected to the rearward planar linkage along a rearward lower connection width and on a side of the forward planar linkage opposite the stepping deck. The stepping deck is substantially wider than any of the forward upper connection width, the rearward upper connection width, the forward lower connection width, and the rearward lower connection width.

In accordance with another embodiment, a retractable vehicle step assist for use with a vehicle having two adjacent doors through which persons may enter the vehicle,

comprises a rigid frame, and a step member having a stepping deck. The step assist further comprises at least two rigid arms connecting the step member to the frame and allowing the step member to move between a retracted position near the frame to a deployed position downward and away from the frame. The stepping deck is of sufficient width to provide a step for persons desiring to enter either of the doors.

In accordance with another embodiment, a retractable vehicle step assist for use with a vehicle having two adjacent doors through which persons may enter the vehicle, comprises a rigid frame, and a step member having a stepping deck. The step further comprises at least two rigid arms connecting the step member to the frame and allowing the step member to move between a retracted position near the frame to a deployed position downward and away from the frame. The stepping deck extends in front of each of the doors when in the deployed position.

In accordance with another embodiment, a retractable vehicle step assist comprises a rigid frame, a step member having a stepping deck, and at least two rigid arms connecting the step member to the frame and allowing the step member to move between a retracted position near the frame to a deployed position downward and away from the frame. The stepping deck is substantially wider than the frame.

In accordance with another embodiment, a retractable vehicle step assist comprises a rigid frame, and a step member having a stepping deck. The step further comprises a forward rigid arm and a rearward rigid arm connecting the step member to the frame and allowing the step member to move between a retracted position near the frame to a deployed position downward and away from the frame. The step member is pivotably connected to the rearward rigid arm at a rearward pivotable connection and the step member rotates downward about the rearward pivotable connection as the step member moves to the deployed position.

In accordance with another embodiment, a retractable vehicle step assist comprises a rigid frame, a step member having a stepping deck, and at least two rigid arms connecting the step member to the frame and allowing the step member to move between a retracted position near the frame to a deployed position downward and away from the frame. The stepping member further comprises a support bracket rigidly connected to the stepping deck and connected to the arms opposite the stepping deck, the support bracket being oriented at an angle to the stepping deck.

In accordance with another embodiment, a method of improving access to a vehicle through a door of the vehicle, comprises attaching a rigid frame to the vehicle, connecting a stepping member having a stepping deck to the frame via at least two rigid arms so that the stepping member is moveable between a retracted position near the frame to a deployed position wherein the stepping deck is situated along the side of the vehicle below the door.

The stepping deck is substantially wider than the frame.

All of these and other embodiments are intended to be within the scope of the invention herein disclosed. This and other embodiments of the present invention will become readily apparent to those skilled in the art from the following detailed description of the preferred embodiments having reference to the attached figures, the invention not being limited to any particular preferred embodiment or embodiments disclosed.

Brief Description of the Drawings Having thus summarized the general nature of the invention and its essential features and advantages, certain preferred embodiments and modifications thereof will become apparent to those skilled in the art from the detailed description herein having reference to the figures that follow, of which: Figure 1 is a side elevation view of a retractable vehicle step in accordance with one preferred embodiment of the invention; Figure 2 is a front elevation view of the retractable vehicle step of Figure 1; Figure 3 is a side elevation view of a retractable vehicle step in accordance with another preferred embodiment of the invention, in the deployed position; Figure 4 is an exploded perspective view of the retractable vehicle step of Figure 3; Figure 5 is a side elevation view of the retractable vehicle step of Figure 3, in the retracted position; Figures 6A-6B are perspective views of the retractable vehicle step as used in connection with a vehicle; Figure 7 is a side view of a further embodiment of a retractable vehicle step, in the extended or deployed position; Figure 8 is a side view of the embodiment of Figure 7, in the retracted position; Figure 9 is a perspective view of the embodiment of Figure 7;

Figure 10 is a perspective view of a clutch assembly for use in connection with the retractable vehicle step; Figure 11 is an exploded perspective view of the clutch assembly of Figure 10; Figure 12 is a perspective view of a further embodiment of the retractable vehicle step, in the deployed position; and Figure 13 is a perspective view of the embodiment of Figure 12, in the retracted position.

Detailed Description of the Preferred Embodiment Figures 1 and 2 depict the lower portion of a vehicle 10 having an underbody 12, an exterior 14, a vertical underbody portion 16 and an under panel 18. A retractable vehicle step 20 is shown associated with the vehicle 10. Referring specifically to Figure 2, the retractable vehicle step 20 has a stepping member 22, which consists of a stepping deck 24 with integrally formed support brackets 26a, 26b, and drive brackets 28a, 28b located inboard of the support brackets 26a, 26b. The support brackets 26a, 26b are pivotally connected to support arms 30a, 30b via clevis pins 32a, 32b, at an end of the support brackets 26a, 26b opposite the stepping deck 24. Similarly, the support arms 30a, 30b are pivotally connected to anchor brackets 34a, 34b via clevis pins 36a, 36b, at an end of each support arm opposite the support brackets 26a, 26b. The anchor brackets 34a, 34b are rigidly connected to the underbody 12 by welding, bolting, riveting or other techniques known to those skilled in the art.

The drive brackets 28a, 28b of the stepping member 22 are pivotally connected to a drive arm 38 via clevis pins 40a, 40b, at an end of the drive brackets 28a, 28b opposite the stepping deck 24. As best seen in Figure 2, the drive arm 38 preferably has an H configuration and is pivotally connected to anchor brackets 42a, 42b via clevis pins 44a, 44b at an end of the drive arm 38 opposite the drive brackets 28a, 28b. The anchor brackets 42a, 42b are rigidly connected to the underbody 12 by welding, bolting, riveting or other techniques known to those skilled in the art.

Thus, in the configuration shown in Figure 2, the support arms 30a, 30b are rotatable about a first axis of rotation A-A which is oriented generally parallel to a lower edge 19 of the vertical underbody portion 16, and the drive arm 38 is rotatable about a second axis of rotation B-B which is also oriented generally parallel to the lower edge 19.

The support arms 30a, 30b and brackets 26a, 26b are rotatable with respect to each other about a third axis of rotation C-C, and the drive arm 38 and drive brackets 28a, 28b are rotatable with respect to each other about a fourth axis of rotation D-D. The third and fourth axes C-C, D-D are oriented generally parallel to the first and second axes A-A, B-B.

In one embodiment, as seen in Figure 1, a first aspect ratio may be defined as the ratio between (1) the distance between the first and second axes A-A, B-B and (2) the length of the arms 30a, 30b as defined by the distance between the first and third axes A-A, C-C. In the embodiment shown in Figure 1, the first aspect ratio is about 0.76. Likewise, a second aspect ratio may be defined as the ratio between (1) the distance between the first and second axes A-A, B-B and (2) the length of the drive arm 38 as defined by the distance between the second and fourth axes B-B, D-D. In the embodiment shown in Figure 1, the second aspect ratio is about 0.91. A third aspect ratio may be defined as the ratio between (1) the distance between the first and second axes A-A, B-B and (2) the distance between the third and fourth axes C-C, D-D. In the embodiment shown in Figure 1, the third aspect ratio is about 1.32.

With reference now to Figure 1, a motor 46 is rigidly mounted to the underbody 12 on a mounting bracket (not shown) adjacent the retractable vehicle step 20. The motor 46 turns a pinion gear 48 about an axis roughly parallel to the plane defined by the underbody 12. The pinion gear 48 meshes with drive teeth 50 formed at the end of the drive arm 38.

Actuation of the motor 46 causes the pinion gear 48 to rotate and the drive arm 38 to counter-rotate with respect to the motor 46 and pinion gear 48, about the clevis pin 44a. As the drive arm 38 rotates it pushes the stepping member 22 by virtue of its connection to the drive brackets 28a, 28b. Thus, when the motor 46 is caused to rotate, the motor 46 moves the retractable vehicle step 20 between a retracted position A wherein the stepping deck is desirably generally positioned inward from the exterior of the vehicle or fixed running board and an extended position B in which the stepping deck is extended sufficiently to provide a step for at least the forefoot portion of a user's foot. As the retractable vehicle step 20 moves between the retracted position A and the extended position B under the power of the motor 46, the support arms 30a, 30b rotate with respect to the clevis pins 36a, 36b and 32a, 32b and support and guide the motion of the retractable vehicle step 20. The extended position B is reached when the support arms 30a, 30b contact a stop 52 which is preferably mounted on the vertical underbody portion 16.

When the retractable vehicle step 20 is in the extended position B, a downward force exerted on the stepping deck 24 causes the support arms 30a, 30b to bear against the stop 52. This arrangement causes the load on the stepping deck 24 to be borne primarily by the support brackets 26a, 26b, support arms 30a, 30b and the stop 52. In the extended position B, the retractable vehicle step 20 takes on a geometry such that the support brackets 26a, 26b, and support arms 30a, 30b are loaded in tension. The clevis pins 32a, 32b define a pivot axis of the stepping member 22. The torque generated by a load on the stepping deck 24 is opposed by the drive arm 38, which is thus loaded in axial compression between the clevis pins 40a, 40b and 44a, 44b. Because the clevis pins 44a, 44b are fixed in the anchor brackets 42a, 42b, the motor 46 is isolated from the load on the stepping deck 24.

This aspect of the retractable vehicle step 20 prevents damage to the motor by eliminating"back-loading,"as there is no torque reaction about the end of the drive arm 38, even when very heavy loads are placed on the stepping deck 24. Thus the motor 46 is not needed to exert a counter-torque on the drive arm 38 to support the load on the stepping deck 24. This feature also eliminates the need for balky, unreliable clutches or any other means of disconnecting the motor 46 from the retractable vehicle step 20, or retractable stops or the like to engage and support the vehicle step 20 when in the extended position.

The retractable vehicle step 20 functions in this manner when in the extended position B so long as the drive arm 38 is rotated further away from the vertical in a counterclockwise direction (as shown in Figure 1) than are the support arms 30a, 30b. That is, when the drive arm 38 is parallel to, or displaced clockwise beyond parallel to, the support arms 30a, 30b, the drive arm 38 will not maintain the support arms 30a, 30b against the stop 52. Rather, the retractable vehicle step 20 will tend to move toward the retracted position A, and the drive arm 38 will tend to rotate counterclockwise (in Figure 1) about the clevis pins 44a, 44b. In this situation the motor 46 would be needed to exert a counter- torque on the drive arm 38, to maintain the retractable vehicle step 20 in the extended position B. As mentioned above, it is undesirable to require the motor 46 to function in this manner.

Advantageously, some or all of the arms 30a, 30b, 38 are connected to the step member 22 within a connection region 31 which is located rearward and upward from the stepping deck 24. This configuration minimizes the length and the downward and forward

travel of the arms 30a, 30b, 38 while facilitating a long overall"reach"for the step 20, with convenient placement of the stepping deck 24 when the step is in the extended position.

Furthermore, this arrangement permits the use, where desired, of an angled step member 22 (see Figure 1) which can be retracted against the underbody 12 with minimal loss of ground clearance.

In one embodiment, when the step 20 is viewed from the side (see Figure 1) the third and fourth axes comprise points in the connection region 31, and a line extending through the points forms an included angle a of about 10 degrees with respect to the upper surface of the stepping deck 24. In another embodiment, the angle a may be between about 5 and 20 degrees. In still other embodiments, the fourth axis may be located anywhere within the connection region 31 rearward and upward of the third axis and the angle a may thus be any angle greater than 0 degrees and less than 90 degrees.

A dust cover or cap 54 may be mounted to the lower body panel 18 to provide a storage location for the stepping member 22 and prevent dust or grime from collecting on the stepping deck 24.

With these features the retractable vehicle step 20 provides a practical stepping assist for a vehicle user, which can be quickly moved into an extended position for use and retracted out of the way when necessary. As detailed above, this functionality is provided with a minimum of mechanical complexity and a high level of reliability. Moreover, the retractable vehicle step 20 is easily connected to a vehicle's existing systems to allow even greater usability. For example, the motor 46 may be connected to the vehicle's electrical system to cause the vehicle step 20 to quickly move to the extended position upon shutting off the vehicle's engine, placing the vehicle in park, opening a door, or signaling the power door-lock system with a remote device or control such as a key fob control. Similarly, the motor 46 may be signaled to retract the vehicle step upon starting the engine, placing the vehicle in drive, closing or locking the door (s) with which the step is associated, etc.

Another embodiment of a retractable vehicle step 120 is shown in Figures 3-5. The retractable step 120 comprises a stepping member 122 that includes a support section or stepping deck 124 bolted or otherwise rigidly connected to an extension section or a support bracket 126. The stepping deck defines an upper stepping surface. Front and rear support arms 130a, 130b are rotatably connected to the support bracket 126 via pins 132a, 132b. A rigid frame 134, which may be configured as necessary for connection to the

vehicle underbody 12, provides a secure mounting for the support arms 130a, 130b which are rotatably mounted to the frame 134 via pins 136a, 136b. It will be appreciated, however, that any suitable structure or technique (other than the frame 134) may be employed to rotatably connect the arms 130a, 130b to the vehicle.

Thus, as best seen in Figure 4, the front support arm 130a is rotatable about a first axis of rotation A-A which is oriented generally parallel to the lower edge 19 (see Figure 5), and the rear support arm 130b is rotatable about a second axis of rotation B-B which is also oriented generally parallel to the lower edge 19. The front arm 130a and the support bracket 126 are rotatable with respect to each other about a third axis of rotation C-C, and the rear arm 130b and the bracket 126 are rotatable with respect to each other about a fourth axis of rotation D-D. The third and fourth axes C-C, D-D are oriented generally parallel to the first and second axes A-A, B-B.

In one embodiment, as seen in Figure 3, a first aspect ratio may be defined as the ratio between (1) the distance between the first and second axes A-A, B-B and (2) the length of the front arm 130a as defined by the distance between the first and third axes A-A, C-C. In the embodiment shown in Figure 3, the first aspect ratio is about 0.75. Likewise, a second aspect ratio may be defined as the ratio between (1) the distance between the first and second axes A-A, B-B and (2) the length of the rear arm 130b as defined by the distance between the second and fourth axes B-B, D-D. In the embodiment shown in Figure 3, the second aspect ratio is about 0.93. A third aspect ratio may be defined as the ratio between (1) the distance between the first and second axes A-A, B-B and (2) the distance between the third and fourth axes C-C, D-D. In the embodiment shown in Figure 3, the third aspect ratio is about 1.35.

With reference to Figure 4, each of the support arms 130 comprises a generally planar, unitary member which forms two coaxial bearing members 131 at either end thereof. The coaxial bearing members may comprise coaxial bores which engage pins in the frame and step member to rotatably connect the support arm to each. In other embodiments the coaxial bearing members may comprise coaxial axle portions which engage bores formed in the frame/step member to provide the rotatable connections.

Alternatively, one or both of the support arms may form a single bearing member at one or both ends, comprising a single full-width bore or a single, central partial-width bore.

The spacing of the coaxial bearing members 131 defines a connection width CW at each end of each support arm. The connection width represents the distance between the opposite ends of the engagement of the bearing members with the frame/stepping member.

For example, in Figure 4 the support arm 130a is rotatably connected to the frame along an upper connection width, which equals the distance between the outer edges of the coaxial bearing members 131. The support arm 130a is connected to the step member along a lower connection width. The support arm 130b likewise defines an upper connection width and a lower connection width. These four connection widths are shown in Figure 4 as being approximately equal, but they may be varied in relative size as desired.

The support arms 130a, 130b also include a rigid crosspiece 133 interconnecting the bearing members 131. The crosspiece is advantageously of sufficient strength to prevent the support arms 130a, 130b from substantially deflecting from their planar configuration when a user steps on the stepping deck 124. The crosspiece may take on any suitable configuration, such as the full-size member shown, or a series of individual cross members extending horizontally or diagonally in an"X"pattern, etc. The high rigidity of the crosspiece and the arms 130a, 130b as a whole advantageously permits the width of the arms to be minimized while nonetheless providing stable support for the stepping deck 124 when in the extended position.

The front and rear support arms may take on other forms and configurations, but desirably each comprises a generally planar linkage connecting the step member to the frame. A"generally planar linkage"may advantageously comprise a generally planar, unitary member such as support arm 130a or support arm 130b as shown in Figure 4. An alternative"generally planar linkage"comprises two or more separate arms (employed in place of a single unitary arm) interconnecting the frame and step member, the arms being coplanar by virtue of a common upper axis of rotation associated with rotatable connection of the arms to the frame, and a common lower axis of rotation associated with rotatable connection of the arms to the step member opposite the frame. As with a unitary arm, a multiple-arm planar linkage defines at either end thereof a connection width extending between the outer edges of the coaxial bearing members formed by the outermost arms making up the linkage.

With further reference to Figures 3 and 4, the support bracket 126 may comprise any suitable structural member having sufficient rigidity to resist bending about its horizontal

and longitudinal axes. Thus the box configuration shown in Figure 4 is particularly suitable, but those skilled in the art will appreciate that the bracket 126 can take on other shapes known to those skilled in the art. The relatively small connection width of the arms 130 permits the bracket 126 to be made of minimal width as well. By making the bracket 126 of sufficient length, the stepping deck 124 will be positioned properly for easy use when the step 120 is in the deployed position (see Figure 3) and the length of the arms 130 can be kept to a minimum.

As best seen in Figure 3, the support bracket 126 preferably forms an angle with the stepping deck 124, and thus extends upward and rearward from the substantially level (when in the extended position) upper surface of the deck 124. Consequently, the preferred angled configuration further enables the length of the support arms 130 to be minimized.

The step member 122 may thus be said to move between an upward-rotated orientation in the retracted position (Figure 5) to a downward-rotated orientation in the deployed position (Figure 3). In other words, the step member 122 rotates downward about its connection with the support arm 130b when moving to the deployed position, and rotates upward about the same connection when moving to the retracted position. When in the retracted position the stepping deck 124 tilts upward, minimizing the total downward protrusion of the retractable step from the vehicle underbody. Desirably, this upward tilt is at least 10° and, preferably at least 20°, to facilitate any water or debris draining off the step and thereby enhance its safety when in use.

With the stepping member 122 moveably connected to the frame 134 via the support arms 130a, 130b, it can be moved between the retracted position A and the extended position B, as shown in Figures 5 and 3, respectively. As with the embodiment described previously, the retractable step 120 provides a sturdy step for a vehicle user when in the extended position B. The geometry of the stepping member 122, support arms 130, and frame 134 causes the arm 130a to be loaded in tension and the arm 130b to be loaded in compression when a load is applied to the stepping deck 124 in a manner similar to that shown in Figure 1. Accordingly, the arm 130b urges the arm 130a against a stop 152 when a user steps on the stepping deck 124, by applying a horizontal reaction force to the step member 122. The stop 152 prevents motion of the drive arm 138 beyond a location chosen so that when the drive arm 138 strikes the stop 152, the step 120 is in a configuration where it tends to move further away from the retracted position upon application of a load to the

stepping deck 124, but is prevented from doing so by virtue of the stop. Due to this convergence of factors, the extended step 120 firmly maintains its deployed position without input from motor 146 (discussed in further detail below), when stepped upon by a user. This feature eliminates the need for a separate locking mechanism, often seen in the form of a hydraulic lock, to maintain the stepping deck in the deployed position when in use. Consequently, this feature enhances the ease of use of the retractable step, as the user is not required to operate or disengage the lock when retracting or deploying the step, thereby eliminating an undesirable aspect of prior-art retractable step systems.

A drive system 137 provides powered movement of the step 120 between the retracted and the extended position. The drive system 137 comprises a drive arm 138 coupled to a rotor 139, both of which are rotatably mounted on the pin 136a, and a motor 146 drivingly connected to the drive arm 138 via the rotor 139. The drive arm 138 is connected to the rotor 139 so as to rotate in concert therewith about the pin 136a. In another embodiment, the rotor and drive arm form an integral unit.

The motor 146 can be mounted to the frame 134, to the vehicle underbody, or in any other suitable location. The motor 146 drives the rotor, drive arm, stepping member, etc. via, for example, a worm gear 147 that meshes with teeth (not shown) formed on the circumference of the rotor 139. In another embodiment, the motor may comprise a linear actuator that pushes or pulls on the circumference of the rotor 139 in order to rotate it in either direction. Of course, any suitable means of coupling the motor to the rotor/drive arm may be used. Advantageously, a window motor may be used to drive the apparatus.

Preferably, the motor will adjust for changes in temperature.

The drive system 137, or any drive system employed with any of the embodiments of the retractable step disclosed herein, may advantageously include a system to stop the motion of the step member, arms, etc. when an obstruction is encountered within the range of motion of the step, or within the moving parts of the step. Such a system reduces the risk of a pinching injury when a person has inadvertently inserted his or her hand, arm, etc. within the mechanism, and also reduces the potential for damaging the step member or other parts of the retractable step when it approaches or strikes a hard object such as a curb.

It is contemplated that a standard anti-pinch/anti-strike system may be used, as is known in the art.

Advantageously, one or both of the arms 130a, 130b are connected to the step member 122 within a connection region 131 (see Figure 3) which is located rearward and upward from the stepping deck 124. This configuration minimizes the length and the downward and forward travel of the arms 130a, 130b while facilitating a long overall "reach"for. the step 120, with convenient placement of the stepping deck 124 when the step is in the extended position. Furthermore, this arrangement permits the use, where desired, of an angled step member 122 which can be retracted against the underbody 12 with minimal loss of ground clearance.

In one embodiment, when the step 120 is viewed from the side (see Figure 3) the third and fourth axes comprise points in the connection region 131, and a line extending through the points forms an included angle P of about 10 degrees with respect to the upper surface of the stepping deck 124. In another embodiment, the angle p may be between 5 and 20 degrees. In still other embodiments, the fourth axis may be located anywhere within the connection region 131 rearward and upward of the third axis and the angle (3 may thus be any angle greater than 0 degrees and less than 90 degrees.

A dust cover or cap 154 may be mounted to the lower body panel 18 to provide a storage location for the stepping member 122 and prevent dust or grime from collecting on the stepping deck 124. The dust cover 154 advantageously has a portion that protrudes downward from the lower surface of the vehicle and extends across the gap formed between the upper surface of the deck 124 and the adjacent vehicle structure, and may extend or curl around the outer edge of the deck 124. Thus the dust cover 154 forms a protective pocket around the outer edge and upper surface of the deck 124. It has been found that the dust cover 154 reduces the accumulation of water, dust, mud and/or debris on the deck, providing a substantial benefit in terms of safety and aesthetics while reducing the chance of soiling the user's clothes when he or she steps on or stands near the deck.

The retractable step thus utilizes a relatively compact linkage system to support the stepping deck 124 when in the deployed position. The relatively short, compact support arms 130 can be made of minimal width, as can the frame 134 and support bracket 126.

The stepping deck 124 can thus be made substantially wider than the frame/support arms/support bracket. In other words the stepping deck 124 is preferably substantially wider than any of the connection width (s) defined by the support arms. Advantageously, the stepping deck is about 2-8 times as wide as the frame, support arms, support bracket or

any of the connection width (s) defined by the support arms. Thus the retractable step provides a wide stepping deck for the vehicle user while minimizing the width and space requirements of the frame, linkage system, etc.

The wide stepping deck 124 and relatively narrow frame/support arms/support bracket permit a single retractable step to serve as a convenient step assist for two adjacent doors of a vehicle, without occupying a large amount of space under the vehicle with the frame, support arms and support bracket. Figure 6A shows a vehicle 200 having on one side thereof a front door 202 and an adjacent rear door 204. In Figure 6A no portion of the retractable vehicle step is visible because it is in the retracted position. Figure 6B shows the stepping deck 124 of the retractable step after it has moved to the extended position (upon opening the front door 202 or in response to other actions as detailed above). It is readily seen that the deck 124 provides a convenient step assist for a person desiring to enter the vehicle through either of the doors 202,204. Where the deck 124 extends in front of about 1/4 of the width of each door, the deck will be sufficiently wider than the user's foot to provide an easy-to-use step. Extending the deck to cover about 1/2 the width of each door provides an additional safety factor above a 1/4-width deck. A deck which extends across substantially the entire width of both doors is most advantageous in that it essentially eliminates the need for the user to look down to the step when placing a foot upon it, facilitating easy use by a person carrying a large number of items with them.

More broadly stated, the novel configuration of the retractable step permits the width of the stepping deck to be selected largely independently of the width of the frame, arms and/or support bracket. Consequently, a stepping deck that is intended to serve as a step for two adjacent doors need not extend the entire width of the doors. It may instead be only about 4-5 feet wide (in comparison to a standard fixed running board which is typically 6-8 feet in width), providing a convenient step while keeping the size and weight of the overall device to a minimum. It has been found that this particular width provides an optimal balance between providing ease of use (via a relatively wide deck) and avoiding an overly large, bulky device. Likewise, the stepping deck of a retractable step intended for use with a single vehicle door may be reduced to an optimal deck width which is less than the entire width of the door.

Figures 7-11 depict another embodiment 220 of the retractable vehicle step, attached to a vehicle underbody 12 having a doorjamb 50 adapted to receive a vehicle door

(not shown), an under panel 18, and a substantially vertical outer panel or surface 52. The retractable step 220 comprises a stepping member 222 that includes a stepping deck 224 bolted or otherwise rigidly connected to a support bracket 226. Front and rear support arms 230a, 230b are rotatably connected to the support bracket 226 via pins 232a, 232b. The rear support arm includes a retraction stop 23 la and a deployment stop 231b. A rigid frame 234, which may be configured as necessary for connection to the vehicle underbody 12, provides a secure mounting for the support arms 230a, 230b which are rotatably mounted to the frame 234 via pins 236a, 236b. The frame 234 may include a forward extension 235 which forms a rail 235a for attachment of the frame 234 to the vehicle underbody 12, via bolting, riveting, welding or other conventional methods. It will be appreciated, however, that a wide variety of structure may be used in place of or in addition to the extension 235 and rail 235a to facilitate attachment of the frame 234 to different vehicle makes and models. Likewise, it will be appreciated that any suitable structure or technique (other than the frame 234) may be employed to rotatably connect the arms 230a, 230b to the vehicle.

The front support arm 230a is rotatable about a first axis of rotation A-A which is oriented generally parallel to the lowest edge or extension 300 of the vehicle underbody 12, and the rear support arm 230b is rotatable about a second axis of rotation (not shown) which is also oriented generally parallel to the lowest edge 300. The front arm 230a and the support bracket 226 are rotatable with respect to each other about a third axis of rotation C- C, and the rear arm 230b and the bracket 226 are rotatable with respect to each other about a fourth axis of rotation D-D. The third and fourth axes C-C, D-D are oriented generally parallel to the first and second axes.

In one embodiment, as seen in Figure 7, a first aspect ratio may be defined as the ratio between (1) the distance between the first and second axes and (2) the length of the front arm 230a as defined by the distance between the first and third axes A-A, C-C. In the embodiment shown in Figure 7, the first aspect ratio is about 0.21. Likewise, a second aspect ratio may be defined as the ratio between (1) the distance between the first and second axes and (2) the length of the rear arm 230b as defined by the distance between the second and fourth axes. In the embodiment shown in Figure 7, the second aspect ratio is about 0.22. A third aspect ratio may be defined as the ratio between (1) the distance between the first and second axes and (2) the distance between the third and fourth axes C- C, D-D. In the embodiment shown in Figure 7, the third aspect ratio is about 1.00.

As depicted in Figures 7 and 8, the retractable step 220 is moveable between a retracted position A and an extended position B. When the step 220 is in the extended position B, a downward force exerted on the stepping deck 24 causes the deployment stop 231b to bear against the front support arm 230a. At this point the step 220 is in a configuration where it tends to move further away from the retracted position B upon application of a load to the stepping deck 224, but is prevented from doing so by virtue of the deployment stop 231b. Due to this convergence of factors, the extended step 220 firmly maintains its deployed position without input from the motor 246 (discussed in further detail below), when stepped upon by a user. This feature eliminates the need for a separate locking mechanism, often seen in the form of a hydraulic lock, to maintain the stepping deck in the deployed position when in use. Consequently, this feature enhances the ease of use of the retractable step, as the user is not required to operate or disengage the lock when retracting or deploying the step, thereby eliminating an undesirable aspect of prior-art retractable step systems.

Advantageously, one or both of the arms 230a, 230b are connected to the step member 222 within a connection region 231 (see Figure 7) which is located rearward and upward from the stepping deck 224. This configuration minimizes the length and the downward and forward travel of the arms 230a, 230b while facilitating a long overall "reach"for the step 220, with convenient placement of the stepping deck 224 when the step is in the extended position. Furthermore, this arrangement permits the use, where desired, of an angled step member 222 which can be retracted against the underbody 12 and/or folded against the arms 230a, 230b to compactly package the step 220 when retracted, which in turn facilitates installation of the step 220 within a small space of the underbody 12, and minimal loss of ground clearance.

In one embodiment, when the step 220 is viewed from the side (see Figure 7) the third and fourth axes comprise points in the connection region 231, and a line extending through the points forms an included angle y of about 50 degrees with respect to the upper surface of the stepping deck 224. In other embodiments, the angle y may be between 20 and 80 degrees, or between 40 and 60 degrees. In still other embodiments, the fourth axis may be located anywhere within the connection region 231 rearward and upward of the third axis and the angle y may thus be any angle greater than 0 degrees and less than 90 degrees.

In the embodiment shown in Figures 7 and 8, the upper surface of the stepping deck 224 may define a substantially horizontal plane in both the extended and retracted positions.

Figures 7,8 and 9 show that the front support arm 230a preferably has a bowed configuration, with a relatively straight midsection between two angled end portions. This preferred geometry ensures that the retraction and deployment stops 231a, 231b will contact the front support arm 230a at a location which is spaced from its rotatable connections to the pins 232a, 236a. It has been found that shear loading of the arm 230a near these connection points, such as that which may occur in the deployed position absent the stop 23 lob, can lead to failure in some circumstances.

In the embodiment presently under discussion, when the retractable step 220 is in the retracted position, it is concealed, preferably completely concealed, from the view of a typical standing adult curbside observer of the vehicle. In this position the stepping member 222, as well as the frame 234 and the remainder of the retractable step 220, is disposed behind the lowest extension or lower edge 300 of the vehicle underbody 12.

Preferably, the forward edge of the stepping deck 224 is spaced at least about 1.5-4.5 inches rearward of the lower portion of the outer panel 52; more preferably, the forward edge is spaced at least about 2.5-3.5 inches rearward of the lower portion of the panel 52; most preferably, the forward edge is spaced at least about 3.2 inches rearward of the lower portion of the panel 52. Furthermore, the lowest-extending point 222a of the stepping member 222 is situated above the lowest extension 300 of the underbody 12, or protrudes such an amount below the extension 300 (and/or is disposed sufficiently rearward of the extension 300) that it substantially remains, and preferably completely remains, out of the field of view of a typical standing adult observer positioned outside of the vehicle. In one embodiment, the retracted step 220 is not visible to an adult standing 5 feet from the vehicle; in another embodiment, the retracted step 220 is not visible to an adult standing 10 feet from the vehicle; in another embodiment, the retracted step 220 is not visible to an adult standing 20 feet from the vehicle.

This concealment is achieved primarily by providing a wide range of motion of the stepping member 222. The front and rear support arms 230a, 230b are made sufficiently long, and/or provided with a sufficiently wide range of angular motion, to move the stepping member 222 rearward and upward into the concealed, retracted position A. The

arms 230a, 230b are also made sufficiently long in comparison to the stepping member 222, and are mounted to the frame 234 on pivot points spaced sufficiently rearward of the extension 300, to move the front edge of the stepping deck 234 behind the extension 300 during retraction. The connection points of the arms 230a, 230b to the frame 234 and stepping member 222 are selected to prevent either arm from interfering with the other's motion over a wide range of travel. The frame 234 includes adequate clearance to accommodate the motion of the stepping member 222 and arms 230a, 230b to and from the retracted position A. Thus, when the member 222 is retracted, substantially no portion of the step 200 is visible to an ordinary"curbside"observer, and a vehicle with the step 220 installed and retracted will appear substantially identical to such an observer, to a"stock" version of the same vehicle.

Figure 9 depicts a preferred drive system 237 for providing powered movement of the step 220 between the retracted and the extended position. The drive system 237 preferably comprises a drive arm 238 which is drivingly coupled to the rear support arm 230b, and is further coupled to a clutch assembly or torque limiter 239. The clutch assembly 239 is in meshing engagement with a primary gear system 240 and a motor 246.

Alternatively, the motor 246 may drive the clutch assembly 239 directly, and the primary gear system 240 may be omitted. A subframe 248 may be provided for mounting the primary gear system 240 and/or motor 246 with respect to the frame 234. The clutch assembly 239 and drive arm 238 are preferably rotatably mounted to the frame 234 so that a driving force on the teeth of the clutch assembly 239 causes the assembly 239 and the drive arm 238 to rotate together and move the step 220 to or from the retracted position.

Figures 10 and 11 show a preferred configuration of the clutch assembly 239 and drive arm 238 in greater detail. The clutch assembly 239 includes a broached or splined hub 250 which is configured for rotatable attachment to the frame 234. The drive arm 238 includes a broached opening 252 to provide a positive connection to the hub 250 when mounted thereon. Adjacent the drive arm 238 is a first clutch member 254 formed from a high-friction clutch material as is known in the art, an input gear 256 having conventional gear teeth for receiving a driving force applied by the primary gear system 240 and/or motor 246, and a second clutch member 258, which is preferably similar to the first clutch member 254. A broached washer 260 covers the clutch member 258, and a bevel spring 262 and nut 264 (threadably engaged with the hub) secure the entire assembly to the hub

250. Thus, under pressure exerted by the spring and nut, the input gear 256 is frictionally coupled to the drive arm 238, hub 250 and washer 260 via the clutch members 254,258.

In normal operation, the input gear 256 and the drive arm 238 will rotate together about their common axis of rotation, acting as if a single component, to drive the step 220 between the retracted and extended positions under the power of the motor 246. However, under appropriate circumstances the clutch members 254,258 will permit slippage to occur between the input gear 256 and the drive arm 238, such that relative angular motion occurs between the gear 256 and the arm 238. One circumstance under which this may occur is when the motor 246 is cut off from its power supply while the step is at or near the extended position, and the vehicle user must manually push the step into the extended position. The clutch permits the step to be manually retracted in this manner without back- loading the motor 246, protecting the motor from damage.

The clutch assembly 239 is also useful in a situation in which the step 220 is being moved under power of the motor, but strikes an obstruction which prevents further motion of the step. In this situation, the clutch prevents damage to the motor (and possible injury where the step has struck a person's hand, leg, etc.) by allowing it to continue turning under the power supplied to it while the step is immobilized, avoiding burn-out of the motor 246.

This provides a further safety measure which can be used, if desired, in conjunction with a standard anti-pinch/anti-strike system as discussed above.

Figures 12 and 13 depict a further embodiment 420 of the retractable vehicle step, in which two or more retraction assemblies 450 are connected to, and provide retraction and deployment of, a single stepping deck 424. Each of the retraction assemblies 450 may comprise structure which generally similar to any of the embodiments disclosed above for the retractable vehicle step; however, the embodiment shown in Figures 12 and 13 utilizes the mechanism disclosed above in connection with Figures 3-5. One or both of the assemblies 450 may include a motor for moving the step between the deployed position (Figure 12) and the retracted position (Figure 13).

The assemblies 450 are preferably coupled to the stepping deck 424 at locations spaced inward from the outer edges of the deck 424. This configuration limits the maximum moment arm defined between a load placed on the deck 424 and either of the connection points to the assemblies 450, and reduces the lateral"footprint"occupied by the step 420 when connecting the step to a vehicle.

Although this invention has been disclosed in the context of certain preferred embodiments and examples, it will be understood by those skilled in the art that the present invention extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses of the invention and obvious modifications and equivalents thereof. Thus, it is intended that the scope of the present invention herein disclosed should not be limited by the particular disclosed embodiments described above, but should be determined only by a fair reading of the claims that follow.