MODULAR SYSTEM OF PLATFORMS FOR USE ON A GROUND SURFACE

Inventor: Wallace N. Hammons

TECHNICAL FIELD

This disclosure relates generally to platforms for holding a user at an elevation above a surface. Uses for this apparatus may include, but are not limited to: providing a platform for standing above a ground surface; altering the height above a ground surface of a platform by providing a modular or stackable system of platforms; moving a platform from one place to another along a ground surface; supporting a toolbox above a ground surface; and providing a railing to help prevent a user from falling off of a platform.

BACKGROUND ART

In many fields, including in the field of automotive maintenance, a need exists to elevate a user some distance above a ground surface. In some cases, the elevation allows a user to reach something that would otherwise be out of reach. In some cases, the elevation allows a user to see something that would otherwise be out of sight. Different heights will be useful to a user in different situations, and different positions of the elevating device will be useful to a user in different situations. In some cases, a user will want to stow an elevating device or system when not in use. In some cases, a user will want to carry only enough of an elevating device or system to reach the desired height. A need exists, then, to provide a modular system of platforms for use on a ground surface.

The present disclosure describes systems and methods for increasing the modularity, customizability, portability, and safety of: providing a platform for standing above a ground surface; altering the height above ground of a platform by providing a modular or stackable system of platforms; moving a platform from one place to another along a ground surface;

4858-9786-3745.1 supporting a toolbox above a ground surface; and providing a railing to help prevent a user from falling off of a platform. Such systems and methods are generally desirable.

SUMMARY OF INVENTION

The present disclosure describes a modular system of platforms for use on a ground surface. In a first exemplary embodiment, a modular system of platforms for use on a ground surface is disclosed, comprising: (1) a bottom platform comprising: a rectangular standing surface having a front side, a rear side, a left side, and a right side, wherein the front side and the rear side are each of a bottom-platform length, wherein the left side and the right side are each of a bottom-platform width, and wherein the front side and the left side connect at a frontleft comer, the front side and the right side connect at a front-right comer, the rear side and the left side connect at a rear-left comer, and the rear side and the right side connect at a rear-right comer; a front-left leg, a front-right leg, a rear-left leg, and a rear-right leg, wherein the frontleft leg connects to and extends downward from the front-left comer, the front-right leg connects to and extends downward from the front-right comer, the rear-left leg connects to and extends downward from the rear-left comer, and the rear-right leg connects to and extends downward from the rear-right comer, wherein the front side of the standing surface, the frontleft leg, and the front-right leg are all oriented in a front vertical plane, wherein the rear side of the standing surface, the rear-left leg, and the rear-right leg are all oriented in a rear vertical plane, and wherein a vertical distance from the standing surface to the ground surface is a bottom-platform height; a front-left wheel-housing connected to the front-left leg, a front-right wheel-housing connected to the front-right leg, a rear-left wheel-housing connected to the rearleft leg, and a rear-right wheel-housing connected to the rear-right leg, each wheel-housing having an opening configured to receive a wheel; a front-left wheel connected to and positioned partially within the front-left wheel-housing, a front-right wheel connected to and positioned partially within the front-right wheel-housing, a rear-left wheel connected to and positioned partially within the rear-left wheel-housing, and a rear-right wheel connected to and positioned partially within the rear-right wheel-housing; and a left step and a right step, wherein the left step is connected to the front-left leg and the rear-left leg, is positioned below and leftward of the standing surface and above the front-left wheel-housing and the rear-left wheel-housing, and is substantially rectangular, and wherein the right step is connected to the front-right leg and the rear-right leg, is positioned below and rightward of the standing surface and above the front-right wheel-housing and the rear-right wheel -housing, and is substantially rectangular; and (2) a booster platform comprising: a rectangular booster-surface having a front boosterside, a rear booster-side, a left booster-side, and a right booster-side; wherein the front boosterside and the rear booster-side are each of a booster-platform length, wherein the left boosterside and the right booster-side are each of a booster-platform width, and wherein the front booster-side and the left booster-side connect at a front-left booster-comer, the front boosterside and the right booster-side connect at a front-right booster-comer, the rear booster-side and the left booster-side connect at a rear-left booster-comer, and the rear booster-side and the right booster-side connect at a rear-right booster-comer; and a front-left booster-leg, a front-right booster-leg, a rear-left booster-leg, and a rear-right booster-leg, wherein the front-left boosterleg connects to and extends downward from the front-left booster-comer, the front-right booster-leg connects to and extends downward from the front-right booster-comer, the rearleft booster-leg connects to and extends downward from the rear-left booster-comer, and the rear-right booster-leg connects to and extends downward from the rear-right booster-comer, and wherein each booster-leg is of a booster-platform height.

In a second exemplary embodiment, a modular system of platforms for use on a ground surface is disclosed, comprising: (1) a bottom platform comprising: a rectangular standing surface having a front side, a rear side, a left side, and a right side, wherein the front side and the rear side are each of a bottom-platform length, wherein the left side and the right side are each of a bottom-platform width, and wherein the front side and the left side connect at a frontleft comer, the front side and the right side connect at a front-right comer, the rear side and the left side connect at a rear-left comer, and the rear side and the right side connect at a rear-right comer; a front-left leg, a front-right leg, a rear-left leg, and a rear-right leg, wherein the frontleft leg connects to and extends downward from the front-left comer, the front-right leg connects to and extends downward from the front-right comer, the rear-left leg connects to and extends downward from the rear-left comer, and the rear-right leg connects to and extends downward from the rear-right comer, wherein the front side of the standing surface, the frontleft leg, and the front-right leg are all oriented in a front vertical plane, wherein the rear side of the standing surface, the rear-left leg, and the rear-right leg are all oriented in a rear vertical plane, and wherein a vertical distance from the standing surface to the ground surface is a bottom-platform height; a front-left wheel-housing connected to the front-left leg, a front-right wheel-housing connected to the front-right leg, a rear-left wheel-housing connected to the rearleft leg, and a rear-right wheel-housing connected to the rear-right leg, each wheel-housing having an opening configured to receive a wheel; a front-left wheel connected to and positioned partially within the front-left wheel-housing, a front-right wheel connected to and positioned partially within the front-right wheel-housing, a rear-left wheel connected to and positioned partially within the rear-left wheel-housing, and a rear-right wheel connected to and positioned partially within the rear-right wheel-housing; and a left step and a right step, wherein the left step is connected to the front-left leg and the rear-left leg, is positioned below and leftward of the standing surface and above the front-left wheel-housing and the rear-left wheel-housing, and is substantially rectangular, and wherein the right step is connected to the front-right leg and the rear-right leg, is positioned below and rightward of the standing surface and above the front-right wheel-housing and the rear-right wheel -housing, and is substantially rectangular; and (2) a railing, having a bottom rail, a top rail, a left rail, and a right rail, wherein the bottom rail and top rail are each of a rail length, wherein the left rail and the right rail are each of a rail height, and wherein the bottom rail is configured to be attached to the rear side of the standing surface.

In a third exemplary embodiment, a modular system of platforms for use on a ground surface is disclosed, comprising: A modular system of platforms for use on a ground surface, comprising: (1) a bottom platform comprising: a rectangular standing surface having a front side, a rear side, a left side, and a right side, wherein the front side and the rear side are each of a bottom-platform length, wherein the left side and the right side are each of a bottom-platform width, and wherein the front side and the left side connect at a front-left comer, the front side and the right side connect at a front-right comer, the rear side and the left side connect at a rearleft comer, and the rear side and the right side connect at a rear-right comer; a front-left leg, a front-right leg, a rear-left leg, and a rear-right leg, wherein the front-left leg connects to and extends downward from the front-left comer, the front-right leg connects to and extends downward from the front-right comer, the rear-left leg connects to and extends downward from the rear-left comer, and the rear-right leg connects to and extends downward from the rearright comer, wherein the front side of the standing surface, the front-left leg, and the front-right leg are all oriented in a front vertical plane, wherein the rear side of the standing surface, the rear-left leg, and the rear-right leg are all oriented in a rear vertical plane, and wherein a vertical distance from the standing surface to the ground surface is a bottom-platform height; a frontleft wheel-housing connected to the front-left leg, a front-right wheel-housing connected to the front-right leg, a rear-left wheel-housing connected to the rear-left leg, and a rear-right wheelhousing connected to the rear-right leg, each wheel-housing having an opening configured to receive a wheel, wherein the front-left wheel-housing and the front-right wheel-housing are oriented in the front vertical plane, and wherein the rear-left wheel-housing and the rear-right wheel-housing is are oriented in the rear vertical plane; a front-left wheel connected to and positioned partially within the front-left wheel-housing, a front-right wheel connected to and positioned partially within the front-right wheel -housing, a rear-left wheel connected to and positioned partially within the rear-left wheel-housing, and a rear-right wheel connected to and positioned partially within the rear-right wheel -housing; and a left step and aright step, wherein the left step is connected to the front-left leg and the rear-left leg, is positioned below and leftward of the standing surface and above the front-left wheel-housing and the rear-left wheelhousing, and is substantially rectangular, and wherein the right step is connected to the frontright leg and the rear-right leg, is positioned below and rightward of the standing surface and above the front-right wheel-housing and the rear-right wheel-housing, and is substantially rectangular; and (2) a lifter comprising: a handle; a lever, having a handle-end, an anchor-end, being of a lever-length, connected to the handle at the handle-end, and making a lever-angle with the handle; an upper anchor comprising an upper angle-stock connected to the anchor-end of the lever and having an upper-anchor horizontal section and an upper-anchor vertical section; a descender connected to the lever between the handle-end and the anchor-end, having a descender-length and making a descender-angle with the lever; and a lower anchor comprising a lower angle-stock connected to the descender and having a lower-anchor horizontal section and a lower-anchor vertical section.

In a fourth exemplary embodiment, a modular system of platforms for use on a ground surface is disclosed, comprising: A platform for use on a ground surface comprising: a rectangular standing surface having a front side, a rear side, a left side, and a right side, wherein the front side and the rear side are each of a platform length, wherein the left side and the right side are each of a platform width, and wherein the front side and the left side connect at a frontleft comer, the front side and the right side connect at a front-right comer, the rear side and the left side connect at a rear-left comer, and the rear side and the right side connect at a rear-right comer; a front-left leg, a front-right leg, a rear-left leg, and a rear-right leg, wherein the front- left leg connects to and extends downward from the front-left comer, the front-right leg connects to and extends downward from the front-right comer, the rear-left leg connects to and extends downward from the rear-left comer, and the rear-right leg connects to and extends downward from the rear-right comer, wherein the front side of the standing surface, the frontleft leg, and the front-right leg are all oriented in a front vertical plane, wherein the rear side of the standing surface, the rear-left leg, and the rear-right leg of are all oriented in a rear vertical plane, and wherein a vertical distance from the standing surface to the ground surface is a platform height; a front-left wheel-housing connected to the front-left leg, a front-right wheelhousing connected to the front-right leg, a rear-left wheel-housing connected to the rear-left leg, and a rear-right wheel-housing connected to the rear-right leg, each wheel-housing having an opening configured to receive a wheel-ski assembly, wherein the front-left wheel-housing and the front-right wheel-housing are oriented in the front vertical plane, and wherein the rearleft wheel-housing and the rear-right wheel-housing are oriented in the rear vertical plane; a front-left wheel connected to and positioned partially within the front-left wheel-housing, a front-right wheel-ski assembly connected to and positioned partially within the front-right wheel-housing, a rear-left wheel connected to and positioned partially within the rear-left wheel-housing, and a rear-right wheel-ski assembly connected to and positioned partially within the rear-right wheel-housing; and a left step and a right step, wherein the left step is connected to the front-left leg and the rear-left leg, is positioned below and leftward of the standing surface and above the front-left wheel-housing and the rear-left wheel-housing, and is substantially rectangular, and wherein the right step is connected to the front-right leg and the rear-right leg, is positioned below and rightward of the standing surface and above the frontright wheel-housing and the rear-right wheel-housing, and is substantially rectangular.

In a fifth exemplary embodiment, a modular system of platforms for use on a ground surface is disclosed, comprising: A platform for use on a ground surface comprising: a rectangular standing surface having a front side, a rear side, a left side, and a right side, wherein the front side and the rear side are each of a platform length, wherein the left side and the right side are each of a platform width, and wherein the front side and the left side connect at a frontleft comer, the front side and the right side connect at a front-right comer, the rear side and the left side connect at a rear-left comer, and the rear side and the right side connect at a rear-right comer; a front-left leg, a front-right leg, a rear-left leg, and a rear-right leg, wherein the frontleft leg connects to and extends downward from the front-left comer, the front-right leg connects to and extends downward from the front-right comer, the rear-left leg connects to and extends downward from the rear-left comer, and the rear-right leg connects to and extends downward from the rear-right comer, wherein the front side of the standing surface, the frontleft leg, and the front-right leg are all oriented in a front vertical plane, wherein the rear side of the standing surface, the rear-left leg, and the rear-right leg of are all oriented in a rear vertical plane, and wherein a vertical distance from the standing surface to the ground surface is a platform height; a front-left wheel-housing connected to the front-left leg, a front-right wheelhousing connected to the front-right leg, a rear-left wheel-housing connected to the rear-left leg, and a rear-right wheel-housing connected to the rear-right leg, each wheel-housing having an opening configured to receive a wheel-ski assembly, wherein the front-left wheel-housing and the front-right wheel-housing are oriented in the front vertical plane, and wherein the rearleft wheel-housing and the rear-right wheel-housing are oriented in the rear vertical plane; a front-left wheel connected to and positioned partially within the front-left wheel-housing, a front-right wheel-ski assembly connected to and positioned partially within the front-right wheel-housing, a rear-left wheel connected to and positioned partially within the rear-left wheel-housing, and a rear-right wheel-ski assembly connected to and positioned partially within the rear-right wheel-housing; and a left step and a right step, wherein the left step is connected to the front-left leg and the rear-left leg, is positioned below and leftward of the standing surface and above the front-left wheel-housing and the rear-left wheel-housing, and is substantially rectangular, and wherein the right step is connected to the front-right leg and the rear-right leg, is positioned below and rightward of the standing surface and above the frontright wheel -housing and the rear-right wheel -housing, and is substantially rectangular; wherein each wheel-ski assembly comprises: an L-shaped bar having a ground-end and a wheel-end; and a ski connected to the ground end and configured to slide on the ground surface; wherein the L-shaped bar is configured to receive a wheel proximate the wheel-end.

BRIEF DESCRIPTION OF DRAWINGS

The following drawings are attached to — and form a portion of — this disclosure:

FIG. 1 is a partial view of a modular system of platforms for use on a ground surface and having a bottom platform.

FIG. 2 is a view of a modular system of platforms for use on a ground surface and having a bottom platform and a railing.

FIG. 3 is a view of a modular system of platforms for use on a ground surface and having a bottom platform and a railing.

FIG. 4 is a partial view of a modular system of platforms for use on a ground surface and having a booster platform.

FIG. 5 is a view of a modular system of platforms for use on a ground surface and having a bottom platform, a booster platform, and a railing.

FIG. 6 is a view of a modular system of platforms for use on a ground surface and having a bottom platform and a railing.

FIG. 7 is a view of a modular system of platforms for use on a ground surface and having a bottom platform, a railing, and a lifter.

FIG. 8 is a side view of a wheel-ski assembly.

FIG. 9 is a view of an embodiment of a bottom platform. DEFINITIONS

Unless otherwise defined, all terms (including technical and scientific terms) in this disclosure have the same meaning as commonly understood by one of ordinary skill in the art of this disclosure. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the specification and should not be interpreted in an idealized or overly formal sense unless expressly defined otherwise in this disclosure. For brevity or clarity, well known functions or constructions may not be described in detail.

The terms “about” and “approximately” shall generally mean an acceptable degree of error or variation for the quantity measured in light of the nature or precision of the measurements. Typical, exemplary degrees of error or variation are within 20 percent (%), preferably within 10 %, more preferably within 5 %, of a given value or range of values. Numerical quantities given in this description are approximate unless stated otherwise, meaning that the term “about” or “approximately” can be inferred when not expressly stated.

The terminology used throughout the disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting. The singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.

The terms “first,” “second,” and the like are used to describe various features or elements, but these features or elements should not be limited by these terms. These terms are only used to distinguish one feature or element from another feature or element. Thus, a first feature or element discussed below could be termed a second feature or element, and similarly, a second feature or element discussed below could be termed a first feature or element without departing from the teachings of the disclosure. Likewise, terms like “top” and “bottom”; “front” and “back”; and “left” and “right” are used to distinguish certain features or elements from each other, but it is expressly contemplated that a top could be a bottom, and vice versa.

The term “consisting essentially of’ means that, in addition to the recited elements, what is claimed may also contain other elements (steps, structures, ingredients, components, etc.) that do not adversely affect the operability of what is claimed for its intended purpose as stated in this disclosure. This term excludes such other elements that adversely affect the operability of what is claimed for its intended purpose as stated in this disclosure, even if such other elements might enhance the operability of what is claimed for some other purpose.

The terms “connected to,” “in connection with,” “in communication with,” or “connecting” include any suitable connection or communication, including any mechanical connection, welded joint, hinge, or fastener.

It is to be understood that any given elements of the disclosed embodiments of the invention may be embodied in a single structure, a single step, a single substance, or the like. Similarly, a given element of the disclosed embodiment may be embodied in multiple structures, steps, substances, or the like.

The following description illustrates and describes the processes, machines, manufactures, compositions of matter, and other teachings of the present disclosure. The disclosure shows and describes only certain embodiments of the processes, machines, manufactures, compositions of matter, and other teachings disclosed; but as mentioned above, it is to be understood that the teachings of the present disclosure are capable of use in various other combinations, modifications, and environments and are capable of changes or modifications within the scope of the teachings of this disclosure, commensurate with the skill and knowledge of a person having ordinary skill in the relevant art. The embodiments described are further intended to explain certain best modes known of practicing the processes, machines, manufactures, compositions of matter, and other teachings of the disclosure and to enable others skilled in the art to utilize the teachings of the disclosure in such, or other, embodiments and with the various modifications required by the particular applications or uses. Accordingly, the processes, machines, manufactures, compositions of matter, and other teachings of the present disclosure are not intended to limit the exact embodiments and examples disclosed herein. Any section headings herein are provided only for consistency with the suggestions of 37 C.F.R. § 1.77 or otherwise to provide organizational cues. These headings shall not limit or characterize the invention(s) set forth herein.

DESCRIPTION OF EMBODIMENTS

Modular systems of platforms for use on a ground surface (and methods for using such systems) have been developed and are described.

Figure 1 is a partial view of a modular system 1 of platforms for use on a ground surface 2 and having a bottom platform 3. The ground surface 2 may be any suitable surface, e.g. a concrete floor, the earth’s surface, the bed of a pickup truck, or the top surface of another platform.

The bottom platform 3 comprises a standing surface 4. The standing surface 4 is shown as rectangular (but may be any suitable shape) and has a front side 5, a rear side 6, a left side 7, and a right side 8. The front side 5 and the rear side 6 are of approximately the same length, viz. the bottom-platform length 9; the left side 7 and the right side 8 are of approximately the same length, viz. the bottom-platform width 10. The bottom-platform length 9 and the bottomplatform width 10 may be any dimension suitable to accommodate at least one user. For example, the bottom-platform length 9 may be approximately 4 feet and the bottom-platform width 10 may be approximately 2 feet. The front side 5 and the left side 7 connect at a frontleft comer 11; the front side 5 and the right side 8 connect at a front-right comer 12; the rear side 6 and the left side 7 connect at a rear-left comer 13; and the rear side 6 and the right side 8 connect at a rear-right comer 14. Sides 5, 6, 7, 8 may connect at comers 11, 12, 13, 14 by any suitable connection — e.g. by a welded joint, by a fastener, or by integral connection. In some embodiments, the standing surface 4 has anon-rectangular shape. In some embodiments, the standing surface 4 may have any suitable number and configuration of sides, comers, and legs.

The bottom platform 3 further comprises a front-left leg 15, a front-right leg 16, a rearleft leg 17, and a rear-right leg 18. The front-left leg 15 connects to and extends substantially downward from the front-left comer 11; the front-right leg 16 connects to and extends substantially downward from the front-right comer 12; the rear-left leg 17 connects to and extends substantially downward from the rear-left comer 13; and the rear-right leg 18 connects to and extends substantially downward from the rear-right comer 14. The legs 15, 16, 17, 18 are configured such that at least three of the legs 15, 16, 17, 18 contact the ground surface 2 when the bottom platform 3 is in a stage orientation 42 (to be contrasted with a rolling orientation 43, described in detail below with reference to Figure 6 and to Figure 7). In some embodiments of the bottom platform 3 — and depending on exact contour of the ground surface 2 — all four of the legs 15, 16, 17, 18 contact the ground surface 2 when the bottom platform 3 is in a stage orientation 42.

A front vertical plane 19 is defined relative to the bottom platform 3. The front side 5 of the standing surface 4, the front-left leg 15, and the front-right leg 16 are all oriented substantially in the front vertical plane 19. A rear vertical plane 20 is defined relative to the bottom platform 3. The rear side 6 of the standing surface 4, the rear left leg 17, and the rearright leg 18 are all oriented substantially in the rear vertical plane 20. A dimension, viz. the bottom-platform height 21, is defined that is the vertical distance from the standing surface 4 to the ground surface 2 when the at least three of the legs 15, 16, 17, 18 contact the ground surface 2. The bottom-platform height 21 may be any suitable height that elevates a user a desired distance above the ground surface 2. For example, the bottom-platform height 21 may be approximately 2 feet. In some embodiments (e.g., to improve safety and stability), the bottom-platform height 21 is not greater than the lesser of the bottom-platform length 9 and the bottom-platform width 10.

In some embodiments, as shown in Figure 1, the front-left leg 15 and the rear-left leg 17 slope outward from the left side 7, and the front-right leg 16 and the rear-right leg 18 slope outward from the right side 8.

The bottom platform 3 further comprises a front-left wheel-housing 22 (connected to the front-left leg 15), a front-right wheel -housing 23 (connected to the front-right leg 16), a rear-left wheel -housing 24 (connected to the rear-left leg 17), and a rear-right wheel -housing 25 (connected to the rear-right leg 18). Wheel -housings 22, 23, 24, 25 are configured to receive and hold (either permanently or removably) a wheel on which the bottom platform 3 may roll (as described in detail below). Figure 1 shows each wheel-housing 22, 23, 24, 25 as taco-shaped and having an opening 26, 27, 28, 29 configured to receive a wheel by being: wide enough to accommodate a wheel; deep enough to cover (and provide an attachment mechanism for) a wheel’s center axle (not specifically shown); and shallow enough to allow a portion of a wheel’s rolling surface (not specifically shown) to protrude from the wheel-housing 22, 23, 24, 25. In some embodiments, other shapes or styles of wheel-housing may be used.

The bottom platform 3 further comprises a front-left wheel 30 (connected to and positioned partially within the front-left wheel -housing 22), a front-right wheel 31 (connected to and positioned partially within the front-right wheel-housing 23), a rear-left wheel 32 (connected to and positioned partially within the rear-left wheel-housing 24), and a rear-right wheel 33 (connected to and positioned partially within the rear-right wheel-housing 25). Wheels 30, 31, 32, 33 may be any wheel or tire suitable for rolling on the ground surface 2. Wheels 30, 31, 32, 33 may connect to wheel-housings 22, 23, 24, 25 by any suitable connection that allows the wheels 30, 31, 32, 33 to roll on the ground surface 2. The bottom platform 3 may comprise only a front-left wheel 30 and a rear-left wheel 32 (i.e., may lack a front-right wheel 31 and a rear-right wheel 33).

The legs 15, 16, 17, 18 and the wheel-housings 22, 23, 24, 25 and the wheels 30, 31, 32, 33 are configured such that, when the bottom platform 3 is in a stage orientation 42, only three or more legs 15, 16, 17, 18 (i.e., neither the wheel-housings 22, 23, 24, 25 nor the wheels 30, 31, 32, 33) contact the ground surface 2.

In some embodiments, as shown in Figure 1, the front-left wheel -housing 22, the frontright wheel-housing 23, the front-left wheel 30, and the front-right wheel 31 are oriented in the front vertical plane 19. In some embodiments, as shown in Figure 1, the rear-left wheel -housing 24, the rear-right wheel-housing 25, the rear-left wheel 32, and the rear-right wheel 33 are oriented in the rear vertical plane 20.

The bottom platform 3 further comprises a left step 34 and a right step 35. The left step 34 has an outer side 36, a top 37, and a bottom 38; the right step 35 has an outer side 39, a top 40, and a bottom 41. The left step 34 is connected to the front-left leg 15 and the rear-left leg 17; the left step 34 is positioned below the standing surface 4; the left step 34 is positioned at least partially leftward of the standing surface 4, extending leftward to an extent less than or approximately equal to the extent of the front-left wheel-housing 22 and the rear-left wheel housing 24; and the left step 34 is positioned above the front-left wheel-housing 22 and the rear-left wheel housing 24. The right step 35 is connected to the front-right leg 16 and the rearright leg 18; the right step 35 is positioned below the standing surface; the right step 35 is positioned at least partially rightward of the standing surface 4, extending rightward to an extent less than or approximately equal to the extent of the front-right wheel-housing 23 and the rear-right wheel-housing 25; and the right step 35 is positioned above the front-right wheelhousing 23 and the rear-right wheel-housing 25. Figure 1 shows steps 34, 35 that are substantially rectangular and that have a width approximately the same as the bottom-platform width 10. In some embodiments, other shapes or styles of step may be used.

Figure 2 is a view of a modular system 1 of platforms for use on a ground surface 2 and having a bottom platform 3 and a railing 44. The railing 44 is shown as rectangular (but may be any suitable shape) and has a bottom rail 45, a top rail 46, a left rail 47, and a right rail 48. The bottom rail 45 and the top rail 46 are of approximately the same length, viz. the rail length 49; the left rail 47 and the right rail 48 are of approximately the same length, viz. the rail height 50. The rail length 49 and the rail height 50 may be any dimension suitable to help prevent a user from falling off of a platform. For example, the rail length 49 may be approximately 3 feet and the rail height 50 may be approximately 4 feet. In some embodiments, the rail length 49 may be approximately equal to the bottom-platform length 9.

The bottom rail 45 is configured to be attached (either permanently or removably) to the rear side 6 of the standing surface 4 by any suitable attachment mechanism. The railing 44 may be configured to be attached to the bottom platform 3 in any other suitable fashion.

In some embodiments the top rail 46 is adapted to receive an object. For example, Figure 2 shows a top rail 46 adapted to receive a toolbox 51 (not shown in Figure 2 but shown in Figure 3) by means of a rail protrusion 52 extending vertically upward from the top rail 46.

Figure 3 is a view of a modular system 1 of platforms for use on a ground surface 2 and having a bottom platform 3 and a railing 44. To illustrate the function of the rail protrusion 52, Figure 3 shows the railing 44 having received a toolbox 51 by means of the rail protrusion 52.

Figure 4 is a partial view of a modular system 1 of platforms for use on a ground surface 2 and having a booster platform 53. The booster platform 53 comprises a booster surface 54. The booster surface 54 is shown as rectangular (but may be any suitable shape) and has a front booster-side 55, a rear booster-side 56, a left booster-side 57, and a right booster-side 58. The front booster-side 55 and the rear booster-side 56 are of approximately the same length, viz. the booster-platform length 59; the left booster-side 57 and the right booster-side 58 are of approximately the same length, viz. the booster-platform width 60. the booster-platform length 59 and the booster-platform width 60 may be any dimension suitable to accommodate at least one user. The booster-platform length 59 is not greater than (in some embodiments, is less than) the bottom-platform length 9 (not shown in Figure 4); the booster platform width 60 is not greater than the bottom-platform width 10 (not shown in Figure 4). For example, the boosterplatform length 59 may be approximately 2 feet and the booster-platform width 60 may be approximately 2 feet. The front booster-side 55 and the left booster-side 57 connect at a frontleft booster-comer 61; the front booster-side 55 and the right booster-side 58 connect at a frontright booster-comer 62; the rear booster-side 56 and the left booster-side 57 connect at a rearleft booster-comer 63; and the rear booster-side 56 and the right booster-side 58 connect at a rear-right booster-comer 64. Booster-sides 55, 56, 57, 58 may connect at booster-comers 61, 62, 63, 64 by any suitable connection — e.g. by a welded joint, by a fastener, or by integral connection. In some embodiments, the booster surface 54 has anon-rectangular shape. In some embodiments, the booster surface may have any suitable number and configuration of sides, comers, and legs.

The booster platform 53 further comprises a front-left booster-leg 65, a front-right booster-leg 66, a rear-left booster-leg 67, and a rear-right booster-leg 68. The front-left boosterleg 65 connects to and extends substantially downward from the front-left booster-comer 61; the front-right booster-leg 66 connects to and extends substantially downward from the frontright booster-comer 62; the rear-left booster-leg 67 connects to and extends substantially downward from the rear-left booster-comer 63; and the rear-right booster-leg 65 connects to and extends substantially downward from the rear-right booster-comer 64. The booster-legs 65, 66, 67, 68 are configured such that at least three of the legs 65, 66, 67, 68 contact either: (1) the ground surface 2 (when the booster platform 53 is placed on the ground surface 2); or (2) the standing surface 4 of the bottom platform 3 (when the booster platform 53 is placed on the bottom platform 3). In some embodiments of the booster platform 53, all four of the legs 65, 66, 67, 68 contact either the ground surface 2 or the standing surface 4 of the bottom platform 3.

A dimension, viz. the booster-platform height 69, is defined that is the vertical distance from the booster surface 54 to the ground surface 2 when the at least three of the legs 65, 66, 67, 68 contact the ground surface 2. The booster-platform height 69 may be any suitable height that either elevates a user a desired distance above the ground surface 2 or elevates a user a desired distance above the ground surface 2 when the booster platform 53 is placed on the bottom platform 3. For example, the booster-platform height 69 may be approximately 1 foot. In some embodiments (e.g, to improve safety and stability), the booster-platform height 69 is not greater than the lesser of the booster-platform length 59 and the booster-platform width 60.

The booster platform 53 is configured to be attached (either permanently or removably) to the rear side 6 of the standing surface 4 by any suitable attachment mechanism — e.g. at the rear-left booster leg 67 and/or the rear-right booster leg 68. The booster platform 53 may be configured to be attached to the bottom platform 3 in any other suitable fashion. The booster platform 53 may be configured to be attached to the bottom platform 3 even when the railing 44 is also attached to the bottom platform 3 (as shown, for example, in Figure 5).

Figure 5 is a view of a modular system 1 of platforms for use on a ground surface 2 and having a bottom platform 3, a booster platform 53, and a railing 44. The bottom platform 3 contacts the ground surface 2. The booster platform 53 is placed on the bottom platform 3 such that such that at least three of the legs 65, 66, 67, 68 contact the standing surface 4 of the bottom platform 3. To illustrate the function of the rail protrusion 52, Figure 5 shows the railing 44 having received a toolbox 51 by means of the rail protrusion 52. Figure 6 is a view of a modular system 1 of platforms for use on a ground surface 2 and having a bottom platform 3 and a railing 44. In Figure 6, the bottom platform 3 is in a rolling orientation 43. When the bottom platform 3 is in a rolling orientation 43, the ground surface 2 is contacted either by both the front-left wheel 30 and the rear-left wheel 32 or by both the front-right wheel 31 and the rear-right wheel 33. The bottom platform 3 is tilted from a stage orientation 42 (shown, for example, in Figure 1) to a rolling orientation 43 by tilting the bottom platform 3 through an angle greater than a contact angle 70. The contact angle 70 is the minimum angle through which the bottom platform 3 must be tilted either: (1) to cause the front-left wheel 30 and the rear-left wheel 32 to make contact the ground surface 2 and to cause all legs 15, 16, 17, 18 to break contact with the ground surface 2; or (2) to cause the front-right wheel 31 and the rear-right wheel 33 to make contact the ground surface 2 and to cause all legs 15, 16, 17, 18 to break contact with the ground surface 2. The contact angle 70 is determined by the configurations of the legs 15, 16, 17, 18 and of the wheel-housings 22, 23, 24, 25 and of the wheels 30, 31, 32, 33.

Figure 7 is a view of a modular system 1 of platforms for use on a ground surface 2 and having a bottom platform 3, a railing 44, and a lifter 71. A user uses the lifter 71 to tilt the bottom platform 3 to a rolling orientation 43. The lifter 71 comprises a handle 72.

The lifter 71 further comprises a lever 73. The lever 73 is a rigid bar. The lever 73 has a handle-end 74 and an anchor-end 75. The lever 73 has a length, viz. the lever-length 76. The lever 73 is connected at the handle-end 74 to the handle 72. The handle 72 and the lever 73 make an angle between them, viz. the lever-angle 77.

The lifter 71 further comprises an upper anchor 78. The upper anchor 78 comprises an upper angle-stock 79 connected to the anchor-end 75 of the lever 73. The upper angle-stock 79 has an upper-anchor horizontal section 80 and an upper-anchor vertical section 81. The lifter 71 further comprises a descender 82 connected to the lever 73. The descender

82 is a rigid bar connected to the lever 73 at a location between the handle end 74 and the anchor-end 75. The descender 82 has a length, viz. the descender-length 83. The descender 82 and the lever 73 make an angle between them, viz. the descender-angle 84.

The lifter 71 further comprises a lower anchor 85. The lower anchor 85 comprises a lower angle-stock 86 connected to the descender 82 opposite the lever 73. The lower anglestock 86 has a lower-anchor horizontal section 87 and a lower-anchor vertical section 88.

The lifter 71 is configured such that, when the lower anchor 85 cradles an outer side 36, 39 of a step 34, 35: (1) the lever 73 can be first rotated such that (a) the lower-anchor horizontal section 87 meets the bottom 37, 40 of the step 34, 35, (b) the lower-anchor vertical section 88 meets the outer side 36, 39 of the step 34, 35, and (c) the upper-anchor horizontal section 80 meets the top 38, 41 of the step 34, 35; and (2) the lever 73 can then be further rotated such that the bottom platform 3 is tilted to a rolling orientation 43.

Figure 8 is a view of a wheel-ski assembly 89. The wheel-ski assembly 89 comprises an L-shaped bar 90 having a ground-end 91 and a wheel-end 92. The wheel-ski assembly 89 further comprises a ski 93 connected to the ground-end 91 and configured to slide on the ground surface 2 (not specifically shown in Figure 8). The L-shaped bar 90 is configured to receive a wheel (e.g, a wheel 30, 31, 32, 33 (not shown in Figure 8)) proximate the wheel-end 92.

Figure 9 is a view of an embodiment of the bottom platform 3. The bottom platform 3 has, in addition to the left step 34 and the right step 35, a second left step 94 and a second right step 95. The wheel-housings 22, 23, 24, 25 are configured to receive and hold (either permanently or removably) a wheel-ski assembly 89. The wheel-housings 22, 23, 24, 25 have been outfitted with wheel-ski assemblies 89. The front-left wheel-housing 22 and the rear-left wheel-housing 24 are each shown with a wheel-ski assembly 89 having received a wheel 30, 32. The front-right wheel-housing 23 and the rear-right wheel-housing 25 are each shown with a wheel-ski assembly 89 not having received any wheel. While the foregoing specification has described specific embodiments of this invention and many details have been put forth for the purpose of illustration or example, it will be apparent to one skilled in the art that the invention is susceptible to additional embodiments and that certain of the details described herein can be varied considerably without departing from the basic principles of the invention.