U.S. patent application number 13/494645 was filed with the patent office on 2013-09-12 for treadmill.
The applicant listed for this patent is Ming-Nan CHEN, Hsuan-Fu Huang. Invention is credited to Ming-Nan CHEN, Hsuan-Fu Huang.
Application Number | 20130237383 13/494645 |
Document ID | / |
Family ID | 49114619 |
Filed Date | 2013-09-12 |
United States Patent
Application |
20130237383 |
Kind Code |
A1 |
CHEN; Ming-Nan ; et
al. |
September 12, 2013 |
TREADMILL
Abstract
A treadmill includes a tread platform and a tread platform
support with a foot rail pivotally connected to the tread platform
and selectively set between a first position and a second position
to support the tread platform in a standing posture. When the tread
platform support is set in the first position, a strut device of
the tread platform and swivel casters of the tread platform support
are stopped at the ground to hold the treadmill vertically and
positively on the ground. When the tread platform support is set in
the second position, two directional rollers of the tread platform
and the swivel casters are attached to the ground, enabling the
treadmill to be moved easily in any direction. Further, the user
can step one leg on the foot rail to shift the position of the
tread platform support steadily and safely.
Inventors: |
CHEN; Ming-Nan; (ChangHua
County, TW) ; Huang; Hsuan-Fu; (ChangHua County,
TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CHEN; Ming-Nan
Huang; Hsuan-Fu |
ChangHua County
ChangHua County |
|
TW
TW |
|
|
Family ID: |
49114619 |
Appl. No.: |
13/494645 |
Filed: |
June 12, 2012 |
Current U.S.
Class: |
482/54 |
Current CPC
Class: |
A63B 22/02 20130101;
A63B 2210/50 20130101 |
Class at
Publication: |
482/54 |
International
Class: |
A63B 22/02 20060101
A63B022/02 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 6, 2012 |
TW |
101107528 |
Claims
1. A treadmill, comprising: a tread platform comprising a base
frame, a strut device connected to a front end portion of said base
frame, and two directional rollers mounted at said front end
portion of said base frame; and a tread platform support comprising
a rack frame and at least one swivel caster mounted at said rack
frame, said rack frame being pivotally connected to said base frame
of said tread platform and selectively set between a first position
and a second position to support said tread platform in a standing
posture, said rack frame comprising a foot rail disposed near the
ground; wherein when said rack frame is in said first position,
said strut device of said tread platform and said at least one
swivel caster of said tread platform support are attached to the
ground and said direction rollers of said tread platform are kept
away from the ground; when said rack frame is in said second
position, said directional rollers of said tread platform and said
at least one swivel caster of said tread platform support are
attached to the ground and said strut device is kept away from the
ground.
2. The treadmill as claimed in claim 1, wherein said base frame of
said tread platform comprises at least one pivot holder defining a
first locating notch and a second locating notch; said rack frame
of said tread platform support comprises at least one coupling end
portion; said tread platform support further comprises at least one
pivot bolt inserted through said at least one pivot holder and said
at least one coupling end portion of said rack frame to pivotally
connect said rack frame to said tread platform, and at least one
lock pin affixed to said at least one coupling end portion of said
rack frame and selectively engaged into one of said first locating
notch and said second locating notch of said at least one pivot
holder to lock said rack frame to said tread platform in one of a
first position and a second position.
3. The treadmill as claimed in claim 2, wherein said at least one
coupling end portion of said rack frame each comprises an elongated
slot; said at least one pivot bolt is respectively inserted through
said at least one pivot holder and the elongated slot of said at
least one coupling end portion to pivotally connect said rack frame
to said tread platform for enabling said tread platform support be
moved axially along said elongated slot relative to said at least
one pivot holder of said base frame.
4. The treadmill as claimed in claim 3, wherein said treat platform
support further comprises at least one spring member connected to
said lock pin and adapted for imparting a pressure to said at least
one lock pin toward said at least one pivot holder to force said at
least one lock pin into one of said first locating notch and said
second locating notch.
5. The treadmill as claimed in claim 4, wherein said rack frame
comprises a transverse rod forming said foot rail.
6. The treadmill as claimed in claim 5, wherein said strut device
comprises two strut rods, each said strut rod comprising a fixed
end connected to said front end portion of said base frame of said
tread platform and a free end for stopping against the ground; the
treadmill further comprises a handrail frame, said handrail frame
comprising two pivot portions pivotally connected to said front end
portion of said base frame and affixed with the fixed ends of said
strut rods; said tread platform further comprises two front foot
members bilaterally mounted at said front end portion of said base
frame and two rear foot members bilaterally mounted at a rear end
portion of said base frame, said front foot members and said rear
foot members protruding over a bottom side of said base frame for
stopping at the ground to have the free ends of said strut rods and
said directional rollers be kept away from the ground when said
tread platform is set in a horizontal position to let the bottom
side of said base frame face toward the ground.
7. The treadmill as claimed in claim 1, wherein said strut device
comprises two strut rods, each said strut rod comprising a fixed
end connected to said front end portion of said base frame of said
tread platform and a free end for stopping against the ground.
8. The treadmill as claimed in claim 7, further comprising a
handrail frame, said handrail frame comprising two pivot portions
pivotally connected to said front end portion of said base frame;
the fixed ends of said two strut rods are respectively affixed to
said pivot portions of said handrail frame.
9. The treadmill as claimed in claim 8, wherein said tread platform
further comprises two front foot members bilaterally mounted at
said front end portion of said base frame and two rear foot members
bilaterally mounted at a rear end portion of said base frame, said
front foot members and said rear foot members protruding over a
bottom side of said base frame for stopping at the ground to have
the free ends of said strut rods and said directional rollers be
kept away from the ground when said tread platform is set in a
horizontal position to let the bottom side of said base frame face
toward the ground.
10. The treadmill as claimed in claim 1, wherein said tread
platform further comprises two front foot members bilaterally
mounted at said front end portion of said base frame and two rear
foot members bilaterally mounted at a rear end portion of said base
frame, said front foot members and said rear foot members
protruding over a bottom side of said base frame for stopping at
the ground to have the free ends of said strut rods and said
directional rollers be kept away from the ground when said tread
platform is set in a horizontal position to let the bottom side of
said base frame face toward the ground.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to treadmills and more
particularly, to such a treadmill, which is safe in use, and can be
erected and steadily positioned on the ground in a standing
position when not in use, or easily moved on the ground by means of
directional rollers and swivel casters.
[0003] 2. Description of the Related Art
[0004] Treadmill is an exercising apparatus popularly seen in
households and sport gyms. To facilitate delivery, a treadmill may
be equipped with two directional rollers at the front side of the
tread platform. When the rear side of the tread platform is lifted
and set in an inclined or erected standing position, the
directional rollers are attached to the ground, allowing the
treadmill to be moved on the ground to a particular place. However,
since the direction rollers can only be rotated forwards and
backwards in one direction, the user must employ much effort to
lift or rotate the treadmill when it is needed to change the moving
direction during movement of the treadmill. This manner is
inconvenient and takes tremendous strength.
[0005] To solve the aforesaid problem, some manufacturers have
directional rollers and swivel casters be installed in a treadmill.
By means of the all-direction steering characteristic of swivel
casters, the treadmill can easily be changed to a different
direction during movement. However, a conventional treadmill
equipped with directional rollers and swivel casters has the
drawbacks of complicated mechanical design and low level of safety.
For example, Taiwan Utility Application No. 093221199 discloses a
treadmill with universal casters. According to this design, two
directional pulleys are provided at a front floor tube at a tread
platform support, and a collapsible swivel caster set is provided
at a rear floor tube at the tread platform support. However, when
going to shift the swivel caster set from a collapsed condition
away from the ground to an operative condition in contact with the
ground, the user must lift the rear floor tube from the ground. At
this time, the whole treadmill is kept in an inclined condition
with the directional pulleys attached to the ground. Under this
condition, the treadmill may fall to the ground accidentally.
SUMMARY OF THE INVENTION
[0006] The present invention has been accomplished under the
circumstances in view. It is the main object of the present
invention to provide a treadmill, which is safe in use, and can be
erected and steadily positioned on the ground in a standing
position when not in use, or easily moved on the ground by means of
directional rollers and swivel casters.
[0007] To achieve this and other objects of the present invention,
a treadmill comprises a tread platform and a tread platform support
with a foot rail pivotally connected to the tread platform and
selectively set between a first position and a second position to
support the tread platform in a standing posture. When the tread
platform support is set in the first position, a strut device of
the tread platform and swivel casters of the tread platform support
are stopped at the ground to hold the treadmill vertically and
positively on the ground. When the tread platform support is set in
the second position, two directional rollers of the tread platform
and the swivel casters are attached to the ground, enabling the
treadmill to be moved easily in any direction.
[0008] Thus, when the rack frame of the tread platform support is
biased relative to the base frame and positioned in the first
position, the strut device is stopped against the ground, and
therefore the treadmill stands steadily on the ground. When the
rack frame of the tread platform support is set in the second
position, two directional rollers of the tread platform and the
swivel casters support the treadmill on the ground, enabling the
treadmill to be moved easily in any direction.
[0009] Further, when shifting the tread platform support between
the first position and the second position, the user can step one
leg on the foot rail of the tread platform support, enabling the
position of the tread platform support to be shifted steadily and
safely and preventing treadmill falling risk as see in the prior
art design during adjustment of the position of swivel casters.
[0010] In one embodiment of the present invention, the tread
platform support comprises two swivel casters. In another
embodiment of the present invention, the tread platform support
comprises one single swivel caster. In other words, either of the
aforesaid two arrangements can achieve the effects of the present
invention. Further, the number of the swivel caster is not limited
to 1 or 2.
[0011] Preferably, the base frame of the tread platform comprises
at least one pivot holder defining a first locating notch and a
second locating notch. The rack frame of the tread platform support
comprises at least one coupling end portion. The tread platform
support further comprises at least one pivot bolt inserted through
the at least one pivot holder and the at least one coupling end
portion of the rack frame to pivotally connect the rack frame to
the tread platform, and at least one lock pin affixed to the at
least one coupling end portion of the rack frame and selectively
engaged into one of the first locating notch and the second
locating notch of the at least one pivot holder to lock the rack
frame to the tread platform in one of a first position and a second
position.
[0012] In one embodiment of the present invention, the base frame
of the tread platform comprises two pivot holders each defining a
first locating notch and a second locating notch; the rack frame of
the tread platform support comprises two coupling end portions, two
pivot bolts and two lock pins. In another embodiment of the present
invention, the base frame of the tread platform comprises one pivot
holder defining a first locating notch and a second locating notch;
the rack frame of the tread platform support comprises one coupling
end portion, one pivot bolt and one lock pin. In other words,
either of the aforesaid two arrangements can achieve the effects of
the present invention, and the number of each related component is
not limited to 1 or 2.
[0013] Preferably, the coupling end portion of the rack frame
comprises an elongated slot; the pivot bolt is inserted through the
pivot holder and the elongated slot of the coupling end portion to
pivotally connect the rack frame to the tread platform for enabling
the tread platform support be moved axially along the elongated
slot relative to the pivot holder of the base frame.
[0014] Preferably, the treat platform support further comprises a
spring member connected to the lock pin and adapted for imparting a
pressure to the lock pin toward the pivot holder to force the lock
pin into one of the first locating notch and the second locating
notch.
[0015] Preferably, the rack frame comprises a transverse rod
forming the foot rail.
[0016] In one embodiment of the present invention, the strut device
comprises two strut rods. Each strut rod has a fixed end connected
to the front end portion of the base frame of the tread platform,
and a free end for stopping against the ground. The treadmill
further comprises a handrail frame. The strut device is not limited
to the design of the two strut rods. For example, the strut device
can be formed of a block member or rod member directly affixed to
the front end portion of the base frame of the tread platform, or a
protrusion formed integral with and protruded from the front end
portion of the base frame.
[0017] In one embodiment of the present invention, the handrail
frame comprises two pivot portions pivotally connected to the front
end portion of the base frame and affixed with the fixed ends of
the strut rods. Thus, the strut rods of the strut device are
indirectly connected to the front end portion of the base frame of
the tread platform by means of the pivot portions of the handrail
frame. Alternatively, the strut device can also be directly affixed
to the front end portion of the base frame of the tread platform,
achieving the same effects, i.e., the connection between the strut
device and the front end portion of the base frame of the tread
platform is not limited to the disclosed indirection connection
design.
[0018] In one embodiment of the present invention, the tread
platform further comprises two front foot members bilaterally
mounted at the front end portion of the base frame, and two rear
foot members bilaterally mounted at a rear end portion of the base
frame. The front foot members and the rear foot members protrude
over a bottom side of the base frame for stopping at the ground to
have the free ends of the strut rods and the directional rollers be
kept away from the ground when the tread platform is set in a
horizontal position to let the bottom side of the base frame face
toward the ground. Thus, when the treadmill is set in a horizontal
condition for use, the tread platform can be steadily supported on
the ground.
[0019] Other advantages and features of the present invention will
be fully understood by reference to the following specification in
conjunction with the accompanying drawings, in which like reference
signs denote like components of structure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a side view of a treadmill in accordance with a
first embodiment of the present invention.
[0021] FIG. 2 is similar to FIG. 1 but illustrating the handrail
frame collapsed.
[0022] FIG. 3 is an elevational view of the first embodiment of the
present invention, illustrating a standing status of the
treadmill.
[0023] FIG. 4 is an enlarged view of the lower part of the
treadmill shown in FIG. 3 when viewed from another angle.
[0024] FIG. 5 is an exploded view of the lower part of the
treadmill shown in FIG. 4.
[0025] FIG. 6 is a vertical side view of the first embodiment of
the present invention, illustrating the tread platform support set
in the first position.
[0026] FIG. 7 is similar to FIG. 6 but illustrating the tread
platform support set in the second position.
[0027] FIG. 8 is a vertical side view of a treadmill in accordance
with a second embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0028] At first, it must be noted that, in the whole detailed
description and claims of the invention, the description of "one
component connected to, pivoted to, or mounted at another
component" means that the component is connected to, pivoted to or
mounted at another component directly, or directly through other
means. Further, for a further understanding of the objects,
features and advantages of the present invention, like reference
numerals refer to like parts throughout the drawings and
specification.
[0029] Referring to FIGS. 1-5, a treadmill 10 in accordance with a
first embodiment of the present invention is shown comprising a
handrail frame 20, a tread platform 30, and a tread platform
support 40.
[0030] The handrail frame 20 comprises two upright bars 22, and a
treadmill console 24 pivotally mounted at the top side of the
upright bars 22. Each upright bar 22 comprises a pivot portion 22a
located on the bottom end thereof and pivotally connected to the
tread platform 30 in such a manner that the upright bar 22 can be
selectively set between an extended operative position shown in
FIG. 1 and a received non-operative position shown in FIG. 2.
Further, the treadmill console 24 provides two grips 24a. The user
can hold the grips 24a with the hands when running on the tread
platform 30, enhancing running stability. The console panel 24 can
also be selectively set relative to the upright bars 22 between the
extended operative position shown in FIG. 1 and the received
non-operative position shown in FIG. 2. As the structure of the
handrail frame 20 is not within the scope of the spirit of the
present invention, any conventional design of handrail frame can be
used with the tread platform 30, and therefore, no further detailed
description in this regard is necessary.
[0031] Further, the tread platform 30 comprises a base frame 32,
two front foot members 33, two rear foot members 34, a strut device
35, and two directional rollers 36.
[0032] The base frame 32 comprises opposing front end portion 32a
and rear end portion 32b. The front foot members 33 and the rear
foot members 34 are respectively mounted at the front end portion
32a and rear end portion 32b, and protruding over a bottom side 32c
of the base frame 32. When the tread platform 30 is set in
horizontal, as shown in FIG. 1, the front foot members 33 and the
rear foot members 34 are stopped at the ground G to support the
treadmill 10 steadily on the ground for enabling the user to use
it. Further, as shown in FIGS. 4 and 5, the base frame 32 comprises
two pivot holders 32d bilaterally located on the bottom side 32c.
Each pivot holder 32d defines a through hole 32e, and a first
locating notch 32f and a second locating notch 32g located on an
arched edge thereof, wherein the location of the first locating
notch 32f is relatively closer to a front end portion 32a of the
base frame 32 than the second locating notch 32g.
[0033] In this embodiment, the strut device 35 is formed of two
strut rods 35a. However, in actual application, the strut device 35
can be formed of other components, for example, one or two block
members. Each strut rod 35a has a fixed end 35b pivotally connected
to the pivot portion 22a of one upright bar 22 of the handrail
frame 20, and a free end 35c for stopping against the ground. Thus,
the two strut rods 35a are indirectly coupled to the front end
portion 32a of the base frame 32 of the tread platform 30 by means
of the pivot portions 22a of the upright bars 22 of the handrail
frame 20. Further, as shown in FIG. 1, when the handrail frame 20
is set in the extended operative position, the strut rods 35a are
kept in an obliquely downwardly extended condition with the free
ends 35c thereof suspending above the ground in a lower front side
relative to the front end portion 32a of the base frame 32 of the
tread platform 30. However, when biased the handrail frame 20 from
the extended operative position to the received non-operative
position shown in FIG. 2, the strut rods 35a are kept in an
obliquely upwardly extended condition with the free ends 35c
thereof suspending in an upper front side relative to the front end
portion 32a of the base frame 32 of the tread platform 30. Further,
it is to be noted that the strut device 35, i.e., the two strut
rods 35a can be directly affixed to the front end portion 32a of
the base frame 32 of the tread platform 30 instead of the indirect
connection design disclosed in this embodiment.
[0034] Further, the two directional rollers 36 are respectively
bilaterally mounted at the bottom side of the front end portion 32a
of the base frame 32 of the tread platform 30. The so-called
"directional rollers" means that the rollers can only be rotated
forwards and backwards in one particular direction, for example,
the two directional rollers 36 can simply be rotated in direction
toward the front side or back side of the treadmill 10.
[0035] Further, the tread platform support 40 comprises a rack
frame 42, two swivel casters 43, two pivot bolts 44, two lock pins
45, two spring members 46, and two screw nuts 47.
[0036] The rack frame 42 of the tread platform support 40 comprises
two support rods 42a, and two transverse rods 42b and 42c connected
between the two support rods 42a at different elevations. Each
support rod 42a comprises a coupling end portion 42d disposed at
the top side thereof, an elongated slot 42e longitudinally formed
in the coupling end portion 42d, and a through hole 42f
transversely formed in the coupling end portion 42d below the
elongated slot 42e. Further, the transverse rod 42c that is
disposed relatively closer to the ground has a certain length and
works as a foot rail.
[0037] Further, the swivel casters 43 are respectively mounted at
the bottom ends of the support rods 42a. The so-called "swivel
caster" means the caster is rotatable in any direction, i.e., the
swivel casters 43 can be turned about a first axis line S1 as well
as a second axis line S2, as shown in FIG. 4.
[0038] When assembling the tread platform support 40, tightly and
respectively press-fit the two lock pins 45 into the through holes
42f of the coupling end portions 42d of the respective two support
rods 42a, and then respectively insert the coupling end portions
42d of the two support rods 42a of the two pivot holders 32d of the
base frame 32, and then respectively insert the pivot bolts 44 into
the through holes 32e of the pivot holders 32d and the elongated
slots 42e of the coupling end portions 42d of the two support rods
42a, and then thread the two screw nuts 47 onto the pivot bolts 44.
Thus, the rack frame 42 is pivotally connected to the tread
platform 30, and the tread platform support 40 can be moved axially
along the elongated slots 42e of the coupling end portions 42d of
the two support rods 42a relative to the two pivot holders 32d of
the base frame 32.
[0039] Thus, when the rack frame 42 is biased relative to the pivot
holders 32d of the base frame 32, the lock pins 45 can be
selectively engaged into the first locating notches 32f or second
locating notches 32g of the pivot holders 32d of the base frame 32
to lock the rack frame 42 to the base frame 32 in a first position
P1 shown in FIG. 6, or a second position P2 shown in FIG. 7.
Further, in this embodiment, the spring members 46 are tensile
springs, having opposing ends thereof respectively fastened to the
pivot bolts 44 and the lock pins 45. Thus, the elastic return force
of the spring members 46 can force the lock pins 45 to position in
the first locating notches 32f or second locating notches 32g of
the pivot holders 32d of the base frame 32, enhancing positioning
stability of the tread platform support 40 in the first position P1
or second position P2. It is to be noted that the type and mounting
location of the spring members 46 are not limited to what is
disclosed. Any other type of spring members capable of providing an
elastic return force to for the lock pins 45 toward the pivot
holders 32d of the base frame 32 can be used.
[0040] After explanation of the structural features of the
component parts of the treadmill 10 and their connection
relationship, the operation of the treadmill 10 will be described
hereinafter.
[0041] As shown in FIG. 1, when the user is going to use the
treadmill, the tread platform 30 is set in a horizontal position to
let the bottom side 32c of the base frame 32 face toward the ground
G. At this time, the front foot members 33 and rear foot members 34
of the tread platform 30 are stopped at the ground G, the free ends
35c of the strut rods 35a and the directional rollers 36 are kept
above the ground G, and the tread platform support 40 is kept in
the position where the swivel casters 43 are disposed adjacent to
the rear end portion 32b of the base frame 32.
[0042] When the user is going to erect the treadmill 10 or to move
the treadmill 10 to another place, turn the handrail frame 20 from
the extended operative position shown in FIG. 1 to the received
non-operative position shown in FIG. 2. At this time, the user can
lift the rear end portion 32b of the base frame 32. When lifting
the base frame 32, the free ends 35c of the strut rods 35a are
stopped at the ground G and work as a fulcrum to support the
treadmill 10 on the ground G, enabling the treadmill 10 to be
stably lifted to an erected condition. During this operation, the
user can step one leg on the foot rail, i.e., the transverse rod
42c of the rack frame 42 of the tread platform support 40, or the
user can apply a pressure through the hand to the tread platform
support 40 to bias the rack frame 42 relative to the base frame 32,
enabling the lock pins 45 to be engaged into the respective first
locating notches 32f or second locating notches 32g to lock the
tread platform support 40 in the first position P1 shown in FIG. 6,
or the second position P2 shown in FIG. 7. Thus, the tread platform
30 is held in a vertical standing posture (see FIG. 6) or a
slightly inclined standing posture (see FIG. 7).
[0043] As shown in FIG. 6, when the tread platform support 40 is in
the first position P1, the strut device 35 of the tread platform 30
and the swivel casters 43 of the tread platform support 40 are kept
attached to the ground, and the directional rollers 36 are spaced
above the ground, and therefore, the treadmill 10 is positively
positioned on the ground.
[0044] Further, if the user wishes to move the treadmill 10 under
this condition, the user can step one leg on the transverse rod 42c
of the rack frame 42 of the tread platform support 40 and push the
base frame 32 with the hands to force the lock pins 45 away from
the respective first locating notches 32f against the spring force
of the spring members 46, and then slightly tilt the base frame 32
to let the tread platform support 40 bias relative to the base
frame 32, enabling the lock pins 45 to be respectively engaged into
the second locating notches 32g, and therefore the tread platform
support 40 is locked in the second position P2 (see FIG. 7). At
this time, the direction rollers 36 of the tread platform 30 and
the swivel casters 43 of the tread platform support 40 are attached
to the ground, and the strut device 35 is kept away from the
ground, and therefore, the treadmill 10 can be moved toward any
direction easily. Further, after the treadmill 10 is moved to the
desired location, the user can one leg on the transverse rod 42c of
the rack frame 42 of the tread platform support 40 to bias the
tread platform support 40 from the second position P2 to the first
position P1, enabling the tread platform 30 to be received in
vertical to save storage space.
[0045] As stated above, when the treadmill 10 is not in use, it can
be held in a vertical standing posture (see FIG. 6), or a slightly
inclined standing posture convenient for movement on the ground in
any direction subject to matching of the directional rollers 36 and
the swivel casters 43. Further, when adjusting the tread platform
support 40 between the first position P1 and the second position
P2, the user can step one leg on the transverse rod 42c of the rack
frame 42 of the tread platform support 40, stabilizing transition
of the posture of the treadmill 10 and avoiding falling of the
treadmill 10 during posture transition.
[0046] In the aforesaid first embodiment of the present invention,
the tread platform support 40 is equipped with two swivel casters
43, however, this arrangement is not a limitation. FIG. 8
illustrates a treadmill in accordance with a second embodiment of
the present invention. According to this second embodiment, the
tread platform support 40 simply provides one transverse rod 42c
workable as a foot rail, one swivel caster 43, one pivot bolt 44,
one lock pin 45, and one spring member 46; the base frame 32 simply
provides one pivot holder 32d. This arrangement achieves the safe
effects as the aforesaid first embodiment of the present invention.
Further, in the aforesaid first and second embodiments, the rack
frame 42 of the tread platform support 40 uses one transverse rod
42c as a foot rail. However, this design is not a limitation. The
rack frame 42 can be configured to provide any structure close to
the ground for stepping by the user.
[0047] Although particular embodiments of the invention have been
described in detail for purposes of illustration, various
modifications and enhancements may be made without departing from
the spirit and scope of the invention. Accordingly, the invention
is not to be limited except as by the appended claims.
* * * * *