Step assembly for vehicles

A step assembly (438) includes two step supporting members (444) which have proximal ends pivotally attached to the underside of a mounting bracket (440). The step supporting members (444) support a plurality of rungs (445). A step plate (446) is attached in cantilevered manner to each of the rungs (445) whereby a rear one of the step supporting members (444) is intermediate the step plate (446) and the front step supporting member. A transmission assembly is provided for causing distal ends of the step supporting members to contact the ground (G) and thereby acquire an extended, angularly inclined position. In one embodiment, the transmission assembly includes an actuator (470). In another embodiment, the transmission assembly includes a motor and cable assembly (472).

BACKGROUND 
1. Field of Invention 
This invention pertains to a step apparatus for vehicles, and particularly 
to a step apparatus which facilitates ingress and egress from vehicles 
with high ground or road clearance. 
2. Prior Art and Other Considerations 
Numerous types of vehicles have high ground clearance, for reasons ranging 
from the sheer size of the vehicle to desirability of roving over rugged 
terrain. For example, large trucks which haul freight have truck beds 
which are, by necessity, considerably elevated from the ground in view of 
the truck size. Other types of vehicles, such as recreational vehicles 
(RVs), although generally midsized, are deliberately elevated to enable 
the vehicles to travel off-road. 
In recent years recreational vehicles (RVs) and light trucks have been sold 
in increasing numbers. These vehicles are now being used not just for 
light hauling and off-road trips, but also for commuting and general 
transportation purposes. The drawback of having high road clearance for 
RVs is that embarking and disembarking the vehicle presents difficulty for 
certain passengers most notably the elderly, the infirm, children, and 
women wearing tight fitting skirts or gowns. 
Previous attempts to overcome the problem of ingress and egress into 
vehicles having high ground clearance fall into two basic categories: 
permanent steps and retractable steps. The first type of step has limited 
effectiveness since the closer the step gets to the ground the more the 
vehicle road clearance is compromised. 
The second type of step, the retractable step, also has certain drawbacks. 
An example of a retractable step is shown in U.S. Pat. No. 3,751,068 to 
Green, wherein the step extends down and out by a cable attached to the 
hinged end of a door. The Green patent does not disclose any way of 
adjusting the height or the number of steps. Furthermore, since the device 
patented by Green can only be used with vehicles which have hinged doors, 
it is not possible to use the device with sliding door vehicles. Finally, 
by attaching the cable to the hinged end of the door, the Green device has 
only limited energy available for extending the step since the distance of 
displacement of the cable is minimal. 
U.S. Pat. No. 3,608,957 (Maneck) shows a horizontal running board for 
vehicles with sliding doors. The Maneck running board extends outwardly 
horizontally by the movement of the door. The Maneck device cannot be 
readily adapted for use with hinged doors. Maneck also does not disclose 
any way of adjusting the number and height of the steps. 
U.S. Pat. No. 3,572,753 to Claassen shows a sole outwardly-angled arm which 
has an oblique orientation of approximately 45.degree. to a horizontal 
frame bar. 
U.S. Pat. No. 4,062,582 to Youmans discloses spaced support arms which are 
not spaced in relation to the longitudinal horizontal axis of the vehicle. 
SUMMARY OF THE INVENTION 
Accordingly, it is an object of the present invention to provide an 
improved step for boarding vehicles of the type having high ground 
clearance. 
An advantage of the present invention is to provide an improved step for 
boarding vehicles which can be used with both sliding and hinged doors. 
A further advantage of the present invention is the provision of an 
improved step apparatus where the number and height of the steps are 
adjustable. 
A further advantage of the present invention is the provision of 
embodiments of an improved retractable step assembly which translates 
energy used or produced in the act of opening and/or closing a vehicle 
door into energy for operating the retractable step assembly. 
A further advantage of the present invention is the provision of 
embodiments of an improved retractable step assembly which uses an 
electric motor for operation. 
Yet another advantage of the present invention is the provision of 
embodiments of an improved retractable step assembly suitable for ingress 
and egress at the rear of a vehicle. 
A step apparatus is provided for vehicles having a high ground/road 
clearance. In some embodiments, the step apparatus is door-position 
responsive, i.e., responsive to the opening and closing of a vehicle door. 
In other embodiments, the step apparatus provides an inclined ladder-like 
arrangement of step plates for facilitating ingress and egress. 
Door-position responsive embodiments of the step apparatus are utilizable 
with either a hinged door or a sliding door. Such apparatus includes two 
step supporting members pivotally attached to the underside of the vehicle 
for adjustably supporting a step or plurality of steps. The proximal ends 
of the step supporting members are spaced apart along a longitudinal 
vehicle axis. At least one of the step supporting members is pivotal about 
a horizontal axis which is perpendicular to vehicle axis. Opening the 
vehicle door causes the step assembly to pivot about an axis perpendicular 
to the longitudinal horizontal axis of the vehicle, thereby extending the 
step assembly for facilitating easy boarding of the vehicle. 
In some door-position responsive embodiments, transmission means include a 
cable which has a first end attached to the locking end of the door and a 
second end attached to a front one of the supporting members. The cable is 
at least partially disposed within a hollow cord which extends through 
portions of the vehicle frame. 
In another door-position responsive embodiment, a cable has a first end 
attached to an electric motor and a second end attached to one of the 
supporting members. A switch, responsive to the position of the door, 
actuates the motor for extension and retraction of the step assembly. 
In some door-position responsive embodiments, a biasing member is used to 
bias the supporting members and attached step to a retracted position 
beneath the vehicle. 
In the inclined ladder embodiments, two step supporting members have 
proximal ends pivotally attached to the underside of a mounting bracket. 
The step supporting members support a plurality of rungs. A step plate is 
attached in cantilevered manner to each of the rungs whereby a rear one of 
the step supporting members is between the step plate and the front step 
supporting member. 
The inclined ladder step embodiments also include transmission means for 
causing distal ends of the step supporting members to contact the ground 
and thereby acquire an extended, angularly inclined position. In one 
embodiment, the transmission means includes an actuator. In another 
embodiment, the transmission means includes a motor and cable assembly.

DETAILED DESCRIPTION OF THE DRAWINGS 
FIG. 1 shows a recreational vehicle 20 having a vehicle body 22 and a 
vehicle undercarriage 24. The vehicle body includes a door 26 hinged to 
the body 22 by hinges 28. Around the vehicle door 26, the vehicle body 22 
further includes a windshield post 30; a top 32; and a center post 34. The 
vehicle 20 has a longitudinal horizontal axis from its front to its rear, 
which axis is depicted by the arrow 36. 
A step assembly 38 of the embodiment of FIG. 1 includes a mounting bracket 
40; a step or platform 42; step supporting members 44 or rails pivotally 
attached to the mounting bracket 40; step assembly biasing means 46; and 
transmission means including cable assembly 48. 
The mounting bracket 40 is a rectangular plate which is secured to the 
vehicle undercarriage 24. The mounting bracket 40 can be secured to 
vehicle undercarriage 24 by any suitable means such as welding, fastening, 
or clamping. In the illustrated embodiment, apertures 41 are provided for 
fastening the bracket 40 to the vehicle undercarriage 24. 
The underside of mounting bracket 40 has two pairs of depending 
semi-circular rings 50 formed therebeneath. The pairs of rings 50 are 
displaced from one another along the direction of axis 36 by a distance 
which is on the order of the length of the step 42. Within each pair of 
rings 50, an outer ring 50a is positioned closer to the step 42 in the 
sense of the width of the bracket 40 (e.g., in the sense of a transverse 
or width axis 51 of the vehicle 20), as seen in FIG. 4. 
Two step supporting members 44 are provided. The step supporting members 44 
each have proximal ends which bear projections 52. In this regard, the 
proximal end of each step supporting member has a first projection 52a 
which extends transversely toward the step 42 and second projection 52b 
which extends toward a centerline of the vehicle 20. A bearing sleeve or 
other friction reducing means is provided in each ring 50 to provide 
smooth pivoting action about axis 51. Accordingly, the step supporting 
members 44 pivotally depend about the rings 50 on mounting bracket 40. 
The proximal ends of the step supporting members 44 are thus spaced apart 
(i.e., are in spaced relation) along the axis 36. Each step supporting 
member 44 is pivotal about a horizontal axis 51 which is perpendicular to 
axis 36. The axis 51 about which each step supporting member pivots 
extends through the projections 52 provided at the proximal ends of the 
members 44. 
The step supporting members 44 also have a plurality of evenly spaced 
apertures 54 for securing at least one step 42 to the step supporting 
members 44. The apertures 54 are provided so that the height of the step 
42 relative to the ground is adjustable. In addition, the apertures 54 
permit the inclusion of further steps should such be desirable. 
The step 42 lies in an essentially horizontal plane. The step 42 has a pair 
of cylindrical support arms 56 attached to the underside thereof. The 
support arms are spaced apart relative to the length of the step (e.g., in 
the sense of arrow 36) at a distance on the order of the separation 
between centerlines of the supporting members 44. Each support arm 56 has 
an end adapted for insertion into a selected one of the apertures 54 
provided in its corresponding step supporting member 44. In this respect, 
apertures 54 are provided with bearing sleeves or other friction reducing 
means so that the support arms 56 can rotate within the apertures 54. 
The support arms 56 also have a plurality of apertures 58 extending 
diametrically therethrough. A selected one of the apertures 58 receives a 
fastener 60 which extends through the step 42 for securing the step 42 to 
the support arm 56. The provision of a plurality of apertures 58 
facilitates positional adjustment of the step 42 relative to width of the 
vehicle body (e.g., transverse to the direction of arrow 36). Thus, the 
user can adjust the step 42 so as to provide a desired clearance from the 
vehicle. 
The step assembly biasing means 46 is securely fastened to the mounting 
bracket 40. The biasing means 46 includes a tightly coiled spring, a first 
end of which is anchored to the mounting bracket 40 and a second end of 
which is connected to a first length of cable 62. The coiled spring is 
located in a housing 63. 
The first length of cable 62 is connected to a distal portion of the rear 
step supporting member 44. As will be seen below, the biasing means 46 
urges the step supporting members 44 to a retracted position (shown in 
FIG. 3) beneath the vehicle body 22 by causing the step supporting members 
44 to pivot about an axis which is perpendicular to the longitudinal axis 
36 of the vehicle 20. 
Referring again to FIG. 1, the transmission cable assembly 48 includes a 
second length of cable 64 which has a first end attached to the front step 
supporting member 44. The cable 64 travels through an aperture in the 
vehicle body 22 to and around a first pulley 68. The first pulley 68 
changes the orientation of the cable 64 so that cable 64 acquires an 
essentially vertical orientation. After the cable 64 passes over the first 
pulley 68, it is threaded through a hollow cord 70. The hollow cord 70 is 
secured to or within the vehicle body 22 so as to remain stationary 
relative to the cable 64. 
The cable 64 travels substantially vertically past the vehicle door 26 
through the windshield post 30 to a second pulley 72. The second pulley 72 
changes the orientation of the cable 64 so that cable 64 now acquires an 
essentially horizontal orientation along the top 32 of the vehicle 20. The 
cable 64 is horizontally disposed along or within the vehicle top 32 until 
it passes through an aperture 74 in the vehicle top. The second end of the 
cable 64, which extends through the aperture 74, is attached to the 
non-hinged edge of the vehicle door 26, i.e., the end of the door which 
engages the vehicle centerpost 34. 
The step assembly 38, of the embodiment of FIG. 5 differs from the 
embodiment of FIG. 1 in the manner in which the transmission cable 
assembly is positioned relative to the vehicle. In this regard, FIG. 5 
shows a sliding door vehicle 20' having a sliding door 26'. A cable 64' is 
attached to the step supporting member 44' which is nearest the front of 
the vehicle 20'. The cable 64' passes over a first pulley 68'; travels 
through hollow cord 70'; and passes over a second pulley 72'. The cable 
passes through aperture 74' and is connected to the vehicle door 26'. 
The step assembly 38" of the embodiment of FIG. 6 also differs from the 
embodiment of FIG. 1 in the manner in which the transmission cable 
assembly is positioned relative to the vehicle. In this regard, FIG. 6 
also shows a hinged door 26" of a vehicle 20". The step assembly 38" of 
the embodiment of FIG. 6 has its biasing means 46" positioned beneath a 
front portion of the mounting bracket 40", rather than beneath a rear 
portion thereof as occurs in FIG. 1. The first length of cable 62" is 
connected from the biasing means 46" to the front supporting member 44". 
The rear supporting member 44" has a first end of the second length of 
cable 64" connected thereto. The second length of cable 64" extends about 
pulley 68" up through the center post 34" of the vehicle 20"; about pulley 
74"; and has its second end connected to the top corner of the locking end 
of the door 26". Portions of the cable 68" extend through a hollow cord 
70". 
The step assembly 38"' of the embodiment of FIG. 7 differs from the 
embodiment of FIG. 6 in the manner in which the force is produced to 
extend the step assembly 38"'. In this regard, FIG. 7 also shows a hinged 
door vehicle 20"'. The embodiment of FIG. 7 obviates the extension of a 
transmission cable through the body 22"' of the vehicle, and instead 
connects the cable 64"' to an electric motor 110 or other force generating 
device attached to the rear portion of the mounting bracket 40"'. The 
electric motor 110 can contain its own battery, be connected to the 
battery of the vehicle 20"', or be otherwise powered. 
The electric motor 110 or other force producing device is securely fastened 
to the mounting bracket 40"'. One end of the cable 64"' is coupled to the 
output shaft of the motor 110 and the other end of cable 64"' is coupled 
to the rear step supporting member 44"'. 
A switch 112 is attached to the center post 34"' of the vehicle 22"'. In 
the illustrated embodiment, the switch 112 is positioned so that closure 
of the door 26"' causes the switch to be held in an "off" position for 
deactivating or reversing the motor 110. Switch 112 is connected to motor 
110 by electrical wires 116. It should be understood that the motor-driven 
embodiment of the step assembly 38"' can be employed with a sliding door 
vehicle as well as with a swinging or hinged door vehicle. 
The step assembly 38"" of the embodiment of FIGS. 8 and 9 can be used with 
either a hinged or sliding door vehicle. Like the embodiment of FIG. 7, 
the step assembly 38"" of FIGS. 8 and 9 is electrically actuated. 
FIGS. 8 and 9 do not show vehicle structure except for a vehicle 
undercarriage 224 and a floorboard 225. In this regard, it is understood 
in FIGS. 8 and 9 that the vehicle has a longitudinal axis depicted by 
arrow 236 (perpendicular to the plane of the sheet of FIG. 9) and a width 
axis depicted by arrow 251 (perpendicular to the plane of the sheet of 
FIG. 8). 
The step assembly 38"" has a mounting bracket means which includes an 
undercarriage mounting bracket 240 and a floorboard mounting bracket 241. 
The undercarriage mounting bracket 240 has an essentially U-shaped channel 
cross section (see FIG. 9) facing upwardly to the underside of the 
floorboard 225. The undercarriage mounting bracket 240 and the floorboard 
mounting bracket 241 are welded or otherwise affixed to the undercarriage 
224 and underside of the floorboard 225, respectively. In addition, the 
floorboard mounting bracket 241 is mounted by an inverted brace 280 to the 
underside of the floorboard 225. The brace 280 is secured to the underside 
of the floorboard by fasteners 281. 
The undercarriage mounting bracket 240 carries transmission means and force 
producing means in its channel. In this respect, the undercarriage 
mounting bracket 240 carries an electrical actuator 284 (which includes an 
electric motor 210) and a first end of transmission shaft 286. The 
electric motor 210 is connected by electrical wiring 287 to a door switch, 
such as door switch 112 of a previously described embodiment. 
The electrical actuator 284 is mounted on the undercarriage mounting 
bracket 240 by an actuator support 290 (see FIG. 9). The electrical 
actuator 284 includes an extendable piston 292. FIG. 8 shows the piston 
292 both in its retracted and extended (phantom) positions. 
The undercarriage mounting bracket 240 also carries a pillow block bearing 
300 through which a first end of the transmission shaft 286 rotatably 
extends. The first end of the transmission shaft 286 extends just slightly 
beyond the pillow block 300, and is connected to the extendable piston 292 
of actuator 284 by a yoked crank 302. 
The floorboard mounting bracket 241 has a flanged bracket 310 depending 
therefrom. A bearing 312 is mounted to the rear of the bracket 310. The 
bracket 310 has an aperture provided therein so that the second end of the 
transmission shaft 286 rotatably extends through the bearing 312 and the 
bracket 310. 
A step supporting member 320 is attached to the second end of the 
transmission shaft 286 protruding from the floorboard mounting bracket. 
The step supporting member 320 is crooked to have a configuration of three 
angled segments, particularly proximate segment 322, intermediate segment 
324, and distal segment 326. At its distal extremity, the distal segment 
326 of the step supporting member 320 has two spaced-apart ears 328 which 
carry a pivot rod 330 therebetween. 
The floorboard mounting bracket 241 also carries another step supporting 
member, particularly step supporting member 350. The step supporting 
member 350 is in the form of a slide. A proximal end of the step 
supporting member 350 is pivotally attached to the floorboard mounting 
bracket 241 so that the member 350 pivots about axis 352 (which is 
perpendicular to the longitudinal axis 236). 
The step supporting member 350 is elongated and slightly arcuate in shape. 
The step supporting member 350 has an elongated arcuate aperture 354 
centrally provided therein. A shaft 360 extends with sliding clearance 
through the aperture 354 in an orientation whereby the axis of shaft 360 
is parallel to the axis 352. Two washers 362 provided on shaft 360 trap 
the step supporting member 350 therebetween. A hex nut 364 is also 
provided on the shaft 360. 
The step assembly 38"" has a step 242 which lies in an essentially 
horizontal plane. Near a front portion thereof, an underside of the step 
242 has the shaft 360 welded thereto. In describing the step 242, the 
"front" is toward the front of the vehicle (e.g., to the right of FIG. 8). 
A rear portion of the step 242 is supported by a crest 370 formed on the 
distal segment 326 of the step supporting member 320. 
Near an intermediate portion of its underside, the step 242 has two 
inverted, triangularly shaped brackets 372 depending therefrom. The 
brackets 372 are spaced apart and carry a pivot pin 374 therebetween. 
A step attachment bar 380 connects the step 242 to the step supporting 
member 320. The step-attachment bar 380 has pivot pin 374 extending 
through a front aperture and the pivot rod 330 carried by the step 
supporting member 320 extending through a rear aperture thereof. 
It should be understood that the mounting bracket means acquires different 
configurations depending on the particular vehicle with which the step 
assembly 38"" is employed. Thus, in another embodiment the mounting 
bracket means is of unitary construction, rather than two separate 
members. 
FIGS. 10 and 11 show an inclined ladder-type embodiment of a step assembly. 
FIG. 10 shows a vehicle 420 having a vehicle body 422 and a vehicle 
undercarriage 424. The vehicle body 422 includes a rear door 426. The 
vehicle 420 has a longitudinal horizontal axis from its front to its rear, 
which axis is depicted by the arrow 436. 
A step assembly 438 of the embodiment of FIG. 10 includes a mounting 
bracket 440; two step supporting members 444; a plurality of rungs 445; 
and a step plate 447 attached in cantilevered manner to each of the rungs 
445. 
The mounting bracket 440 is a rectangular plate which is secured to the 
vehicle undercarriage 424. As with the previously described embodiments, 
the mounting bracket 440 can be secured to vehicle undercarriage 424 by 
any suitable means such as welding, fastening, or clamping. 
The underside of mounting bracket 440 has two pairs of depending 
semi-circular rings 450 formed therebeneath. The pairs of rings 450 are 
displaced from one another along the direction of axis 436 by a distance 
which is on the order of the width of the step supporting members 444. 
As indicated above, two step supporting members 444 are provided. As used 
herein, the step supporting member which is closest to the front of the 
vehicle is referred to as the front step supporting member, while the step 
supporting member which is fartherest from the front of the vehicle is 
referred to as the rear step supporting member. 
The step supporting members 444 each have T-shaped proximal ends with 
projections 452 which fit into the rings 450 depending from the mounting 
bracket 440. A bearing sleeve or other friction reducing means is provided 
in each ring 450 to provide smooth pivoting action about axis 451. 
Accordingly, the step supporting members 444 pivotally depend about the 
rings 450 on mounting bracket 440. 
The proximal ends of the step supporting members 444 are thus spaced apart 
(i.e., are in spaced relation) along the axis 436. Each step supporting 
member 444 is pivotal about the horizontal axis 451 which is parallel to 
axis 436. The axis 451 about which each step supporting member 444 pivots 
extends through the projections 452 provided at the proximal ends of the 
members 444. 
Each of the rungs 445 is essentially cylindrical in shape and has a rung 
axis 460 (see FIGS. 13 and 15). Each rung 445 has a first (front) end 
rigidly anchored in the front step supporting member 444. Each rung 445 
has an intermediate portion which extends through an aligned aperture in 
the rear step supporting member 444 and has its second (rear) end 
protruding from the rear step supporting member 444. Thus, each rung 445 
is supported by the two step supporting members 444, with a first end of 
each rung extending beyond the rear step supporting members 444 and thus 
slightly beyond the rearmost extent of the vehicle 420. 
The rungs 445 are welded or otherwise fixedly fastened to the step 
supporting members 444. The rungs 445 are stationary with respect to the 
step supporting members 444. 
A step plate 446 is fixedly attached or welded in cantilevered manner to 
the rear end of each of the rungs 445. The step plate 446 includes a flat 
surface which, when the step assembly 438 is in its extended position, is 
oriented to be parallel with the horizontal. Accordingly, with respect to 
the axis 460 of each rung 445, the rear step supporting member 444 is 
intermediate the step plate 446 and the front step supporting member 444. 
The step assembly 438 also includes transmission means for causing distal 
ends of the step supporting members 444 to contact the ground and thereby 
acquire the fully extended position. In the embodiment of FIGS. 12 and 13, 
the transmission means includes an actuator 470. In the step assembly 438, 
of the embodiment of FIGS. 14 and 15, the transmission means includes a 
motor and cable assembly 472. 
The actuator 470 of the embodiment of FIGS. 12 and 13 is mounted to the 
underside of the mounting bracket 440. A distal end of an actuator piston 
474 is attached to an intermediate point on a crossbar member 476. The 
crossbar member 476 is rigidly mounted between the front and rear step 
supporting members 444. The actuator 470 is electrically controlled by a 
remote switch, such as a switch positioned in the vehicle cab and 
connected to the actuator by an unillustrated electrical cable. A further 
electrical cable is provided to enable the actuator 470 to operate on 
current supplied by the vehicle battery. 
The motor and cable assembly 472 of the embodiment of FIGS. 14 and 15 
includes an electric motor 480 which is mounted to the underside of the 
mounting bracket 440. The electric motor 480 is connected to a first end 
of a cable 482 and is operable to wind and unwind the cable 482. A second 
end of the cable 482 is connected to a crossbar member 484. The crossbar 
member 484 is rigidly mounted between the front and rear step supporting 
members 444 below the lowest (leftmost) step plate 446 (as shown in FIGS. 
14 and 15). The electric motor 480 is responsive to a switch 486, which 
may be located either on the motor 480 or located remotely (as in the 
vehicle cab and connected to the actuator by an electrical cable). An 
unillustrated electric cable is provided to enable the electric motor 480 
to operate on current supplied by the vehicle battery. 
OPERATION 
In operation, as the door 26 of vehicle 20 of FIG. 1 is pivoted to its 
opened position, the cable 64, having its second end connected to the door 
26, is pulled in the direction shown by across 90. As the cable 64 is 
pulled in the direction of arrows 90, the force on the cable 64 overcomes 
the tension of biasing means 46 and causes the step supporting members 44 
to pivot in the counterclockwise sense (shown by arrow 92 in FIG. 1) for 
extension to an essentially perpendicularly dependent position as shown in 
FIGS. 2 and 4. In overcoming the tension of biasing means 46, the cable 64 
passes over first pulley 68 through the vehicle body 22 via hollow cord 70 
along the windshield post 30 to the second pulley 72 through the 
horizontal section of hollow cord 70 along the top 32 of the vehicle body 
22 to aperture 74 and out to the point on the vehicle door 26 where the 
cable 64 is attached. 
The first pulley 68 thus acts to translate essentially horizontal motion of 
the transmission means into essentially vertical motion. The second pulley 
72 operates to translate essentially vertical motion into essentially 
horizontal motion. The distal ends of the step supporting members 44 
thereby descend in a vertical direction (e.g. below the vehicle 20) when 
in the extended vertical position. 
When the vehicle door 26 is pivoted to the closed position, the force 
formerly applied by cable 64 is relaxed, permitting biasing means 46 to 
exert its biasing force on step supporting members 44, thereby rotating 
the step supporting members 44 about axis 51 (which is perpendicular to 
the longitudinal axis of the vehicle 20) in the clockwise sense as shown 
by arrow 94 in FIG. 3. The plane of the step thus translates vertically 
between the retracted and extended positions. 
The step assembly 38" of the embodiment of FIG. 6 operates in a similar 
manner as the embodiment of FIG. 1. However, the biasing means 46" exerts 
a counterclockwise force on the step assembly 38". Upon opening of the 
door 26, the cable 64" has forces exerted thereon in the direction of 
arrows 90" to apply a clockwise rotational force (in the direction of 
arrow 92") on the step assembly 38". 
When the door 26' of the vehicle 20' of the embodiment of FIG. 5 is slid to 
its opened position, the cable 64' pulls the step supporting members 44' 
to the extended position against the tension of the biasing means 46'. The 
cable 64' passes over first pulley 68' through the vehicle body 22' via 
hollow cord 70' along the windshield post 30' to the second pulley 72' to 
aperture 74' and out to the point on the vehicle door 26' where the cable 
64' is attached. When the vehicle door 26' is slid, moved, pushed, or 
swung to the closed position, biasing means 46' causes step supporting 
members 44' to rotate about an axis which is perpendicular to the 
longitudinal horizontal axis 36' of the vehicle 20'. 
For doors which open as sliding doors along a track, it is easier to 
convert the sliding motion to energy for extending the step assembly. 
Factors enhancing ease of operation include the fact that people generally 
use two hands when opening a sliding door, and the fact that the entire 
force applied to displace the door can be utilized instead of a vectorial 
component thereof. Hence, a sliding door can be easily coupled to 
translate the door's movement along the horizontal axis to the step 
assembly's pivoting about an axis which is perpendicular to the horizontal 
longitudinal axis of the vehicle. 
Thus it is seen the present invention provides a retractable step assembly 
which is connected to the locking end of a door, as opposed to a hinged 
end of a door, to ensure that the maximum amount of energy available from 
opening the door will be used to operate the extension. In addition, the 
step assembly pivots about an axis which is perpendicular to the 
longitudinal horizontal axis of the vehicle. 
When the door 26"' of the embodiment of FIG. 7 is pivoted to the open 
position, switch 112 will be in an "on" position, thereby causing 
activation of the electric motor 110. Activation of the motor 110 causes 
the cable 64"' to be wound or otherwise pulled about the output shaft of 
the motor 110, overcoming the bias of biasing means 46"', and thereby 
pulling the cable 64"' (and thus the step supporting members 44"') in the 
direction of arrow 90"' until the step assembly 38"' is pivoted to the 
extended position. 
When the vehicle door 26"' is pivoted to the closed position, the output 
shaft of the electric motor 110 is relaxed or reversed, depending on the 
type of motor 110 employed, with the result that the biasing means 46"' 
successfully exerts its biasing force on the step supporting members 44"' 
to urge the step supporting members 44"' into the retracted position. 
Again, it should be understood that the embodiment of the step assembly 38" 
of the embodiment of FIG. 7 works in the same manner on a sliding door 
vehicle as on a hinged door vehicle. Moreover, it should also be 
understood that the relation of the switch 112 and motor 110 components of 
the step assembly 38"' can easily be reversed so that, if opening the door 
26"' turns off the switch 112, the motor can be made to be responsive to 
the "off" position of the switch 112 to extend the step assembly 38". For 
the embodiment of FIG. 7, the extension and retraction of the step 
assembly is related to the opening and closing of the vehicle door but 
does not directly depend upon energy exertion of the user. Hence, no 
additional energy is required to open a door with the step assembly 38"', 
the assembly 38"' being automatic. For the embodiment of FIGS. 8 and 9, 
when the vehicle door is opened, switch 112 is opened causing the piston 
292 of electric motor 210 to retract. Retraction of piston 292 pivots 
shaft 286 and the step supporting member 320 in the clockwise direction 
about the axis of shaft 286. Consequently, the step supporting member 320 
is vertically extended. As the step supporting member 320 is vertically 
extended (e.g., lowered), the step-attachment bar 380 pulls the step 242 
into a vertically lowered position shown by solid lines in FIG. 8. 
When the vehicle door is closed, the switch 112 is closed causing the 
piston 292 of the electric motor 210 to extend. Extension of piston 292 
pivots shaft 286 and the step supporting member 320 in the 
counterclockwise direction about the axis of shaft 286. Consequently, the 
step supporting member 320 is vertically retracted to assume the position 
shown by phantom lines in FIG. 8. As the step supporting member 320 is 
vertically retracted (e.g., raised), the step 242 is pushed upwardly. The 
upward force caused by the vertical elevation of the step supporting 
member 320 causes the shaft 360 to slide up the aperture 354 provided in 
the other step supporting member 350. 
It should be understood that the embodiment of FIGS. 8 and 9 can also be 
installed for a rear opening door of a vehicle. In such a configuration, 
the axes about which the step supporting members 320 and 350 pivot are 
parallel to the longitudinal axis of the vehicle. 
When the switch of the embodiment of FIGS. 10-13 is pressed to extend the 
step assembly 438 from its retracted position (seen in FIG. 10) to its 
extended position (seen in FIG. 12), the piston 474 of the actuator 470 is 
extended to permit the step supporting members 444 (connected to the 
piston 474 by the crossbar member 476) to pivot in the counterclockwise 
direction (shown by arrow 490) about the axis 451. When the piston 474 is 
fully extended, the distal ends of the step supporting members 444 contact 
the ground G or road upon which the vehicle 420 is parked. Upon full 
extension of the piston 474, the step supporting members 444 together lie 
in a plane (out of the sheet of FIG. 12) which is angularly inclined (at 
angle 492 as shown in FIG. 12) with the ground G. 
When the actuator 470 is to raise the step assembly 438 of the embodiment 
of FIGS. 10-13, the piston 474 is retracted, thereby pivoting the step 
supporting members 444 upwardly in a clockwise direction (as indicated by 
arrow 494 in FIG. 12). The step assembly is drawn up beneath the mounting 
bracket 440 as closely as the actuator 470 will permit, ultimately into 
the position shown in FIG. 10. The actuator 470 itself can be selectively 
pivotally mounted underneath the mounting bracket 440 to facilitate snug 
fitting under the mounting bracket 440. 
When the switch of the embodiment of FIGS. 14-15 is pressed to extend the 
step assembly 438 from its retracted position (seen in FIG. 10) to its 
extended position (seen in FIG. 11), the motor 480 permits the cable 482 
to be unwound by the gravitational weight of the step supporting members 
444 (connected to the cable 482 at the crossbar member 484). The step 
supporting members 444 thereby pivot in the counterclockwise direction 
(shown by arrow 490) about the axis 451. When the cable 482 is fully 
unwound, the distal ends of the step supporting members 444 contact the 
ground G or road upon which the vehicle 420 is parked. 
When the motor 480 winds the cable 482 of the embodiment of FIGS. 14-15, 
the distal ends of the step supporting members 444 are lifted upwardly, 
with the result that the step supporting members 444 pivot in a clockwise 
direction (as indicated by arrow 494 in FIG. 14). The step assembly is 
drawn up beneath the mounting bracket 440 as closely as the motor 480 will 
permit, ultimately into the position shown in FIG. 10. 
If necessary, the embodiment of FIGS. 14 and 15 can be provided with 
biasing means to bias the step supporting members 444 (at a crossbar 
thereof) to the mounting bracket 440. 
While the invention has been particularly shown and described with 
reference to the preferred embodiments thereof, it will be understood by 
those skilled in the art that various alterations in form and detail may 
be made therein without departing from the spirit and scope of the 
invention. For example, the step assembly 438 of the embodiments of FIGS. 
10-15 can be mounted to service a side door of a vehicle rather than a 
rear door.