Mobile fall protection unit for flatbed platforms

A mobile fall protection unit can be maneuvered by hand and brought to a flatbed with readily deployable, temporary fences for worker fall protection. The mobile fall protection unit can include a chassis, which carries a frame, which in turn carries a ladder as well as selectively deployable fall protection devices for worker fall protection. The frame carries a pair of retractable fall barriers separated from each other by about the width of the back of the flatbed.

Not applicable.

FIELD OF THE INVENTION

The subject matter disclosed herein generally involves a fall protection system for workers loading and unloading flatbeds.

BACKGROUND OF THE INVENTION

Flatbeds are used for transporting cargo and can take several forms such as flatbed trucks, detachable flatbed trailers and flatbed rail cars. When these flatbeds can be maneuvered into a loading bay where the cargo can be loaded onto the flatbed or unloaded from the flatbed, infrastructure typically is available to provide fall protection for the workers who perform the loading and unloading functions. However, worker fall protection typically is not available when the flatbed is isolated from such infrastructure. Similarly, when the number of flatbeds needing to be loaded or unloaded exceeds the number of available loading bays at the facility, worker fall protection typically is not available for the excess flatbeds, leading to costly delays in the loading/unloading process. Additionally, maneuvering a flatbed into a particular bay where worker fall protection is available requires an available tractor to connect to the flatbed and a competent driver of the tractor in order to complete this maneuver. This process too results in costly delays in the loading/unloading process.

BRIEF DESCRIPTION OF THE INVENTION

Some of the aspects and advantages of the invention are set forth below in the following description, or may be obvious from the description, or may be learned through practice of embodiments of the invention.

One embodiment of the invention includes a mobile fall protection unit that can be maneuvered by hand and brought to the flatbed with readily deployable, temporary fences for worker fall protection. The mobile fall protection unit can include a chassis that desirably is carried above the underlying ground by a plurality of rotatable wheels. Desirably, two wheels are mounted at the rear of the chassis and two wheels are mounted at the front of the chassis, one front wheel carrying each of the front two legs. The front of the chassis has a width between the two front wheels that is approximately equal to, but slightly larger than, the width of the rear end of a flatbed. The rear wheels can be mounted close together on a rear wheel carriage that is pivotally mounted with respect to the rear of the chassis. The rear wheel carriage can be steered by a handle that itself is pivotally connected to the rear wheel carriage between a storage position and a towing position. The chassis can be steered by hand or moved by a vehicle into an operating position that places the front end of the chassis against the rear end of a flatbed. To keep the front of the chassis snug against the back end of the flatbed, a respective tie strap desirably extends from each respective front leg of the chassis to a respective one of the respective rub rails that extends along each of the two longitudinally extending sides of the flatbed. The chassis carries a pair of retractable fall barriers separated from each other by about the width of the back of the flatbed. The bottom border of each retractable fall barrier desirably is disposed at an elevation just beneath the height of the flatbed and anchored by a lower cable that can have its tension adjusted by a manually operable lower winch carried on the front leg.

Each retractable fall barrier can include a fencing panel that is hung from rings threaded on an upper cable that is strung between vertical stanchions and that is tensioned by a manually operated upper winch that is carried by the chassis. The fencing panel desirably is formed as drapeable web or mesh that is rectangular in shape with a width that is the desired height of a fall protection fence for a flatbed. The length of the fencing panel is intended to be long enough to stretch at least from the rear end of the flatbed along the longest side of the flatbed to the front end of the flatbed. The fencing panel desirably is stored in an accordion-like folded condition on a storage rod that has one end connected to the upper portion of a front leg and elongates to a free end in a horizontal direction parallel to the ground. When the operator decides to deploy the fencing panel, the operator pulls the fencing panel away from the storage rod on the front leg. Each fencing panel can be pulled manually along the upper cable and deployed along one side of the flatbed and attached temporarily to a selectively positionable post that can be anchored at the front end of the flatbed where typically a bulkhead is located. Once the winch is set to the proper condition of tension in the cable, then this chassis-based, fall protection device is ready to be used while workmen are working on top of the walking surface of the flatbed.

The mobile fall protection unit can include a ladder carried by the frame at the front of the chassis and selectively positionable between the two front legs of the chassis. The ladder can be pivotally mounted so that it can be deployed selectively as a step ladder from the ground to the height of the flatbed or folded up for storage between the two front legs of the chassis. The ladder also is easily detachable from the frame at the front of the chassis so that the ladder can be positioned selectively by the user to either side of the frame at the front of the chassis. The frame at the front of the chassis also desirably is provided with stationary fence posts from which can be hung chains or other constraints that provide selectively removable fall protection to the rear of the flatbed.

The shadow that the chassis casts on the underlying ground desirably is an outline that has a T-shape with the frame at the front end of the chassis forming the top of the “T”. The handle has a lower end pivotally connected to the rear wheel carriage. The handle is shaped so that when pivoted with the free end of the handle pointing to the front of the chassis, the free end of the handle is angled upwardly relative to the horizontal plane that is parallel to the ground. The handle so shaped and the T-shaped chassis enable a plurality of the mobile fall protection units to be stored together in a compact arrangement by having the front end of a first chassis slide over against the rear end of a second chassis and permit the front end of the second chassis to slide over against the rear end of a third chassis and so on in the same manner with additional chasses of mobile fall protection units. In this way the chasses of several mobile fall protection units can be successively nested with respect to one another in a line for storage when not in use without taking up an inordinate amount of space in the loading area.

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate at least one presently preferred embodiment of the invention as well as some alternative embodiments. These drawings, together with the written description, serve to explain the principles of the invention but by no means are intended to be exhaustive of all of the possible manifestations of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to exemplary embodiments of the invention, one or more examples of which are illustrated in the accompanying drawings. The detailed description uses numerical and letter designations to refer to features in the drawings. Like or similar designations in the drawings and description have been used to refer to like or similar parts.

It is to be understood that the ranges and limits mentioned herein include all sub-ranges that exist within the prescribed limits, inclusive of the limits themselves unless otherwise stated. For instance, a range from 100 to 200 also includes all possible sub-ranges, examples of which are from 100 to 150, 170 to 190, 153 to 162, 145.3 to 149.6, and 187 to 200. Further, a limit of up to 7 also includes a limit of up to 5, up to 3, and up to 4.5, as well as all sub-ranges within the limit, such as from about 0 to 5, which includes 0 and includes 5 and from 5.2 to 7, which includes 5.2 and includes 7.

As used herein, the horizontal generally defines a direction that is normal to the direction in which the force of gravity acts and thus is generally parallel to the underlying ground surface. The vertical generally defines a direction that is parallel to the direction in which the force of gravity acts and thus is generally normal to the horizontal and normal to the underlying ground surface.

One embodiment of components of the mobile fall protection unit of the present invention in a partially deployed mode of operation is shown in a perspective view inFIG. 1and generally designated by the numeral20. As explained more fully below, a presently desirable embodiment of the mobile fall protection unit20desirably includes a chassis30, which is connected to a frame50, which in turn carries a ladder70as well as selectively deployable fall protection devices60,67for worker fall protection. As shown inFIG. 1for example, an embodiment of the mobile fall protection unit20has been brought to the rear end of a flatbed trailer, which is generally designated by the numeral15.

Referring toFIGS. 2, 2A and 3for example, an embodiment of a mobile fall protection unit20can include a chassis, which is generally designated by the numeral30. The chassis30desirably includes a pair of horizontally spaced apart front legs31. Each front leg31desirably is formed by a straight length of tubular steel having a square transverse cross-sectional shape as shown inFIGS. 2, 2A and 3for example. As shown inFIG. 1for example, the spacing between the front legs31is designed to be approximately slightly greater than the anticipated width of the walking surface15aof the flatbed15.

As shown inFIGS. 2, 2A and 3for example, each front leg31has a bottom end connected, as by welding, to a front wheel carriage35. Each front leg31elongates to extend vertically from its respective front wheel carriage35. Each of the front wheel carriages35includes a pair of downwardly pending members35athat are spaced apart from each other to form a front wheel fork. The depending members35aof each front wheel fork are spaced apart just enough so that a front wheel36ais rotatably mounted between them. Each of the two front wheels36aat the front end of the chassis30rotates about a commonly disposed axis of rotation35b.

As shown inFIGS. 2, 2A and 3for example, a rear wheel carriage38desirably is spaced horizontally apart from and to the rear of the two front legs31. Each rear wheel36brotates about its own rear wheel axle37a, the opposite ends of which being held between a pair of spaced apart depending members38aof the rear wheel carriage38. Each of the two front legs31and the rear wheel carriage38is disposed at one of the three vertices of a triangular footprint. The chassis30desirably is carried by the wheels36a,36bthat render the mobile fall protection unit20mobile. While the wheels36a,36bare not self-propelled, the mobile fall protection unit20desirably can be maneuvered by hand and/or by connection to a self-propelled vehicle that can push or pull the mobile fall protection unit20on its wheels36a,36b. As shown inFIGS. 1-3, 5 and 5Afor example, each of the four independently rotatable wheels36a,36bdesirably is a solid, hard rubber wheel.

As noted above, the mobile fall protection unit20includes a frame50. As shown inFIGS. 2, 2A and 3for example, the frame50desirably elongates in straight line and has one end connected, as by welding, to the inward side of one of the front legs31and an opposite end similarly connected to the other one of the front legs31. Alternatively, each of the opposite ends of the frame50desirably can be connected to a respective leg31by threaded bolts and nuts for example. Desirably, the frame50is connected to the front legs31so that the horizontally disposed uppermost free edges of the frame50are disposed at a sufficient height above the ground so that the uppermost free edges of the frame50are disposed at a height that is approximately equal to or slightly less than the anticipated height of the walking surface15aof the flatbed15shown inFIG. 1for example.

As shown inFIGS. 2, 2A and 3for example, in addition to the two front legs31and the rear wheel carriage38, the chassis30also includes a spinal member32that desirably elongates in a straight line and has one end connected to the frame50at a location that desirably is disposed midway between the two opposite ends of the frame50. As shown inFIGS. 2 and 2Afor example, the opposite end of the spinal member32desirably is connected to one opposite end of a branch member33that elongates in a straight line, which as shown inFIG. 2Ais disposed at an angle α with respect to the straight line direction of elongation of the spinal member32. The angle α desirably is an obtuse angle in a range of about 120 degrees to about 165 degrees. Thus, the end of the spinal member32connected to the frame50is disposed at a higher elevation above the rear wheel carriage38than the elevation of the end of the spinal member32that is pivotally connected to the rear wheel carriage38. The branch member33desirably is pivotally connected to the rear wheel carriage38and disposed so that its direction of elongation is parallel with the horizontal plane that is itself parallel to the underlying ground surface.

As shown inFIGS. 2 and 2Afor example, the spinal member32of the chassis30elongates substantially in a straight line in a direction. As shown inFIG. 2A, the spinal member32of the chassis30elongates in a direction that is disposed at an angle β above the plane that is parallel to the ground and parallel with the direction of elongation of the branch member33. Thus, the two angles α, β are complementary. As shown inFIG. 8for example, this tripod footprint and upwardly angled orientation of the spinal member32of the chassis30lends itself to the ability to nest multiple mobile fall protection units20into one another in a nested storage arrangement that minimizes the floor space taken up by the stored units20.

Each of the front legs31of the chassis30, the spinal member32and the branch member33desirably is formed of a strong rigid material such as a tubular steel member with a hollow interior. Similarly, the frame50also desirably is formed of a strong rigid material such as a tubular steel member with a hollow interior. For example each of the front legs31of the chassis30desirably is formed of tubular steel, which desirably is powder-coated but can be galvanized, that has hollow square transverse outer dimensions measuring four inches by four inches with the walls measuring three sixteenths of an inch thick. Similarly, each of the frame50and the spinal member32and the branch member33of the chassis30desirably is formed of hollow tubular steel, which desirably is powder-coated but can be galvanized, that has square transverse outer dimensions measuring four inches by four inches and walls measuring three sixteenths of an inch thick.

As shown inFIGS. 2, 2A and 3for example, the rear wheels36bcan be mounted close together on the rear wheel carriage38, which is pivotally mounted with respect to the spinal member32and the branch member33of the chassis30. The rear wheel carriage38is pivotally connected via a pivot post38bto the branch member33of the chassis30.

The chassis30is configured so that it can be steered by hand or moved (pulled or pushed) by a vehicle into an operating position that places the frame50and front end of the chassis30against the back end of a flatbed15as shown inFIGS. 1, 2A5and5A for example. As shown inFIGS. 1-3for example, the pivotally connected rear wheel carriage38desirably can be steered by an angled handle40. As shown inFIGS. 2 and 2Afor example, the handle40desirably is pivotally connected to the rear wheel carriage38via the two more widely spaced apart ends41aof the legs of a steering fork41. The more narrowly spaced apart ends41bof the legs of the steering fork41are disposed opposite the more widely spaced apart ends41aof the legs of the steering fork41and are connected to a shorter leg40aof the angled handle40.

The handle40desirably is formed as a unitary structure of tubular steel having a square transverse cross-sectional shape. However, the shorter leg40aand a longer leg40bof the handle40meet to form a bend at an obtuse angle θ, which desirably measures about 165 degrees as schematically shown inFIG. 2Afor example. As schematically shown inFIG. 5Afor example, the angle ψ between the steering fork41and the longer leg40bof the handle40is about 196 degrees. The mud flaps14behind the rear wheels of the flatbed15also are schematically depicted inFIG. 5A.

As shown inFIGS. 2 and 2Afor example, a pull-bar42is disposed near the free end of the longer leg40bof the handle40and extends transversely with respect to the longer leg40bof the handle40. Though the handle40is shown in the storage position inFIGS. 2 and 8for example, each ofFIGS. 1 and 2Adepicts the handle40in a different towing position. The handle40has this range of pivotal movement between the storage position depicted inFIGS. 2 and 8and the towing position shown inFIG. 1.

Three mobile fall protection units20are shown inFIG. 8resting against each other in a nested arrangement, which is a relative orientation suited for storage of the mobile fall protection units20in a minimum amount of space. The handle40of each fall protection unit20shown inFIG. 8has a lower end pivotally connected to the rear wheel carriage38in which the two rear wheels36bare rotatably supported. The handle40is shaped so that when pivoted with the free end of the handle40pointing to the front of the chassis30as inFIGS. 2 and 8for example, the free end of the handle40is angled upwardly relative to the horizontal plane in which the ground resides. As shown inFIG. 8for example, the handle40so shaped and the chassis30so shaped enable a plurality of the mobile fall protection units20to be stored together in a compact nested arrangement by having the rear of a chassis30nest within the wedge-shaped space in the rear of a neighboring chassis30and successively permitting the rear of another neighboring chassis30to nest within the wedge-shaped space within the rear of its wedge-shaped chassis30. Thus, both the chasses30and the handles40are shaped to allow the nesting storage arrangement shown inFIG. 8. In this way the mobile fall protection units20can be stacked for storage when not in use without taking up an inordinate amount of space in the loading area.

As shown inFIGS. 5 and 5Afor example, each embodiment of the mobile fall protection unit20desirably includes a pair of tie straps45. One respective tie strap45desirably is provided on a respective one of each of the two legs31of the chassis30. As shown inFIGS. 5 and 5Afor example, one end of each tie strap45desirably can be anchored to a respective one of the front legs31. As shown inFIG. 5for example, one end of each tie strap45desirably can be anchored to the outwardly facing depending member35aof the respective front wheel carriage35. As shown inFIG. 5Afor example, one end of each tie strap45desirably can be anchored to the outwardly facing portion of the top of the respective front wheel carriage35from which the depending member35ahangs. Each tie strap45is long enough to extend from one side of the front leg31to one of the respective sides of the flatbed15. The opposite end of each tie strap45desirably terminates in a hook (not visible in the view ofFIG. 5) that can be secured to the side of the flatbed15. As shown inFIGS. 2, 2A, 5 and 5Afor example, each tie strap45is selectively deployable from and storable on a length-adjustable tensioning device47that desirably is provided so that the operator readily can select the length of the tie strap45necessary to the securing task. The length-adjustable tensioning device47can be set by the operator to maintain tension at the desired length of the tie strap45to ensure that the front of the frame50remains snugly against the rear end of the flatbed15.

As shown inFIGS. 2, 2A and 3for example, connected to each opposite side of the spinal member32of the chassis30, there is at least one stanchion pocket21that desirably is formed by a strip of metal bent to the configuration of a sleeve with a rectangular transverse cross-sectional shape and open at the top and bottom. As shown inFIGS. 2, 2A and 3for example, the stanchion pocket21desirably is welded to the side of the spinal member32. Desirably, two stanchion pockets21are disposed on each side of the spinal member32. As shown inFIG. 3for example, each stanchion pocket21is configured to receive therein a respective lower section22a,23aof a respective vertically elongating rigid stanchion22or23. Additionally, the respective lower section22aor23aof each such stanchion22or23desirably is configured to be received easily and snugly into the type of stanchion pocket17that conventionally is found disposed along the sides of a flatbed15as shown inFIGS. 5, 5A, 6 and 7for example.

As shown inFIGS. 1, 3, 7 and 7Afor example, one of the vertically elongating rigid posts that can be stored on each side of the spinal member32is a front anchor stanchion22or122. As shown inFIGS. 2A and 7Afor example, a presently preferred embodiment of a vertically elongating rigid post that can be stored on each side of the spinal member32is a front anchor stanchion122. As shown inFIGS. 7 and 7Afor example, the lower end of each respective embodiment of a front anchor stanchion22,122terminates in a sturdy ring24, which desirably is formed of powder-coated steel but also can be formed of galvanized steel. A sturdy loop25, which desirably is formed of powder-coated steel but also can be formed of galvanized steel, is connected to elongate away from the rear edge of the upper end of the front anchor stanchion22,122. As shown inFIG. 7for example, a plurality of eyelets26is disposed along the rear edge of the front anchor post22, and these eyelets26desirably are spaced equidistantly apart. As shown inFIG. 7Afor example, a single eyelet26is disposed along the rear edge of the front anchor post122, and this single eyelet26desirably is disposed at about half the height of the portion of the front anchor post122that rises above the walking surface15aof the flatbed15when the lower section122aof the front anchor stanchion122is received through a forward-positioned, conventional stanchion pocket17that is formed along the side of a flatbed15and positioned near the bulkhead16of a flatbed15.

As shown inFIG. 7for example, a sturdy loop27, which desirably is formed of powder-coated steel but also can be formed of galvanized steel, is connected to elongate away from the front edge of the front anchor stanchion22and desirably is positioned near the upper end of the front anchor stanchion22. As shown inFIG. 7Afor example, a sturdy loop127, which desirably is formed of powder-coated steel but also can be formed of galvanized steel, is attached as by welding on the front edge of the front anchor stanchion122and desirably is positioned near the upper end of the front anchor stanchion122and disposed at a fixed angle of descent of about 45 degrees from the direction of elongation of the front anchor stanchion122. As shown inFIGS. 7 and 7Afor example, a stop collar28is disposed between the respective lower section22a,122aof the respective front anchor stanchion22,122and the lowest eyelet26and is configured and disposed so as to prevent the further descent of the respective front anchor stanchion22,122into one of the stanchion pockets17typically found in the side of the flatbed15. The respective lower section22a,122aof the respective front anchor stanchion22,122is the portion of the respective front anchor stanchion22,122that extends between the stop collar28and the lower end that terminates in the steel ring24.

As shown inFIGS. 2A and 7Afor example, the presently preferred embodiment of the front anchor stanchion122includes a guard rail122b. The guard rail122bdesirably is formed from a length of ⅛ inch gauge aluminum tubing that has been bent into a C-shape. The outer transverse perimeter of the aluminum tubing forming the guard rail122bdesirably is a square that measures one inch on each side. The two free ends of the guard rail122bdesirably are fixed, as by being bolted, to the upper portion of the front anchor stanchion122. As shown inFIG. 7A, the guardrail122bfunctions to reduce the space between the front anchor stanchion122and the bulkhead16. However, a gap of less than 19 inches desirably can be left between the bulkhead16and the guardrail122b.

As shown inFIGS. 2, 2A, 3 and 5Afor example, each of the front legs31desirably is provided with a pair of winch platforms34a,34b. Each winch platform34a,34belongates in a rearward direction away from the front leg31and generally parallel to the direction of elongation of the spinal member32of the chassis30. As shown inFIGS. 2, 2A and 5Afor example, each front leg31carries a lower winch platform34adisposed beneath and spaced apart from an upper winch platform34b, the former being disposed between the upper winch platform34band the front wheel carriage35of the front leg31.

As shown inFIG. 5Afor example, each winch platform34a,34bcarried on each front leg31desirably can be formed of a length of C-channel having the end farther from the respective winch51or53bias cut from front to back where the respective winch51or53is attached. The respective winch51or53is attached to the middle portion of the C-channel, which desirably is disposed in a plane that is parallel to the plane of the ground. The opposing depending flanges of the length of C-shaped channel forming each winch platform34a,34bare pointing downward in the same general direction as the bracing panel39bshown inFIG. 4.

As shown inFIG. 4for example, each winch platform34a,34bcarried on each front leg31desirably can include a base39aand a bracing panel39b, which desirably is disposed beneath the base39aso as to support and reinforce the base39a. The base39adesirably can take the form of a flat metal plate shaped like a rectangle having one of the narrower edges welded to the rearward facing side of the front leg31. The flat upper surface of the base39aof each winch platform34a,34bdesirably is disposed in a plane that is parallel to the plane of the ground. The bracing panel39bdesirably can take the form of a flat metal plate shaped like a trapezoid having the longer one of the two parallel edges of the bracing panel39bwelded to the outwardly facing longer edge of the base39awith the angled edge of the bracing panel39bfacing outwardly away from the front leg31. The remaining edge of the bracing panel39bconnects the two parallel edges and desirably elongates in a straight line that is disposed in a direction that is normal to direction in which the lines of the two parallel edges of the bracing panel39belongate and desirably is welded to the rearward facing side of the front leg31.

In accordance with the present invention, the mobile fall protection unit20desirably includes at least one selectively deployable fall protection device that is at least in part carried by the frame50. As explained more fully below, the mobile fall protection unit20desirably includes several selectively deployable fall protection devices as well as more than one type of selectively deployable fall protection device.

As shown inFIG. 1for example, one type of selectively deployable fall protection device is a fall barrier60that desirably includes a fencing panel61. As shown inFIGS. 1, 2 and 2Afor example, the fall barrier60includes the front leg31, a lower winch51, and a lower cable52selectively deployable from and storable on the lower winch51, an upper winch53, and an upper cable54selectively deployable from and storable on the upper winch53. As shown inFIGS. 1, 7 and 7Afor example, each fall barrier60also includes a front anchor stanchion22or122. The fencing panel61desirably is selectively extendable between the front leg31, which is positioned at one end of the frame50of the mobile fall protection unit20and positioned at the rear end of the flatbed15as shown inFIGS. 5 and 5A, and the front anchor stanchion22or122, which is positioned at the front end of the flatbed15near where the bulkhead16of the flatbed15typically is disposed as shown inFIG. 7 or 7A. When fully deployed as shown inFIG. 1for example, the fencing panel61of the fall barrier60will extend along the entire length of one side of the flatbed15to the front of the flatbed15so as to provide fall protection on one of the opposite elongated sides of the flatbed15for workers on the walking surface15aof the flatbed15. Thus, as shown inFIGS. 1, 5, 5A, 7 and 7A, each respective fencing panel61can be deployed lengthwise between the chassis30and one of the rigid front anchor stanchions22or122and height-wise between the upper cable54and the lower cable52that are attached to the respective front anchor stanchion22or122.

The mobile fall protection unit20desirably includes at least a second one of this first type of selectively deployable fall protection device60carried by the chassis30and positioned on the front leg31at the opposite end of the frame50to extend along the opposite side of the flatbed15when the mobile fall protection unit20is positioned at the rear end of the flatbed15as shown inFIGS. 5 and 5Afor example. Thus, the chassis30desirably carries a pair of this type of retractable fall barrier60, and they desirably are separated from each other by about slightly more than the width of the rear of the flatbed15. As shown inFIGS. 5, 5A, 6, 7 and 7Afor example, the bottom edge of each fencing panel61desirably is disposed at an elevation just below the height of the walking surface15aof the flatbed15. Each such first type of fall barrier60provides a readily deployable, temporary fence for protecting workers from falling from one of the longer sides of the flatbed15.

As shown inFIGS. 1, 5, 5A, 6, 7 and 7Afor example, the fencing panel61of the fall barrier60desirably is formed as a long length of drapeable net or sheet that is rectangular in shape with a width that substantially equals the height of a desired fall protection fence for a flatbed15. Thus, a typical width of the fencing panel61desirably falls in a range of from about 36 inches to about 48 inches. The length of the fencing panel61is intended to be long enough to stretch at least from the rear end of the flatbed15along the longest side of the flatbed15to the front of the flatbed15and typically is in a range of 45 feet to 55 feet in length. The fencing panel61desirably is formed of material that is strong enough to the task of protecting workers from falling off the side of the flatbed15and typically is formed of synthetic fibers woven into a strong synthetic cord that in turn is used to form a net with square openings measuring about three inches on a side and having an area of about nine square inches.

As shown inFIGS. 5-7Afor example, the elongated top edge of the fencing panel61desirably is defined by a top border strip62. A plurality of slide rings62adesirably is attached permanently to the top border strip62. Each slide ring62adesirably is formed from a length of three-eighths inch in diameter cylindrical steel rod that is bent into a circle having an inside diameter of about four inches. Each slide ring62adesirably is formed of powder-coated steel but also can be formed of galvanized steel. Apart from the two individual slide rings62aat each opposite end of the top border strip62of the fencing panel61, each individual slide ring62adesirably is spaced apart from its two nearest neighboring slide rings62aby a linear distance of about two feet when the fencing panel61is stretched in a taut condition.

As shown inFIGS. 5-7Afor example, the elongated bottom edge of the fencing panel61desirably is defined by a bottom border strip63. A plurality of loops63adesirably is attached permanently to the bottom border strip63. Each loop63adesirably is formed from a length of one quarter inch in diameter cylindrical steel rod that is bent into a circle having an inside diameter of about two and one half inches. Each loop63adesirably is formed of powder-coated steel but also can be formed of galvanized steel. Apart from the two individual loops63aat each opposite end of the bottom border strip63of the fencing panel61, each individual loop63adesirably is spaced apart from its two nearest neighboring loops63aby a linear distance of about eighteen inches when the net is stretched in a taut condition.

As shown inFIGS. 5 and 5Afor example, the narrower end edge at the rear of the fencing panel61is defined by a rear border strip64. As shown inFIGS. 7 and 7Afor example, the narrower end edge at the front of the fencing panel61is defined by a front border strip64. Desirably, each of the front border strip64and the rear border strip64is identically configured. As shown inFIG. 5for example, one end of each of a plurality of anchoring straps64adesirably is attached permanently to the rear border strip64. Similarly, as shown inFIG. 7for example, one end of each of a plurality of anchoring straps64adesirably is attached permanently to the front border strip64.

As shown inFIGS. 5 and 7for example, the opposite end of each of the front and rear anchoring straps64adesirably is connected to an attachment clip64bthat selectively can be attached and detached by hand to a respective eyelet26. As shown inFIG. 7for example, the attachment clip64bon an anchoring strap64aconnected to the front border strip64desirably can be selectively attached and detached to one of the eyelets26that is connected to the rear side of the front anchoring post22. Similarly, as shown inFIG. 5for example, the attachment clip64bon an anchoring strap64aconnected to the rear border strip64desirably can be selectively attached and detached to one of the eyelets26that is connected to the front side of a respective front leg31of the chassis30.

As shown inFIG. 5Afor example, one end of a center anchoring strap164adesirably is attached permanently at the middle of the rear border strip64. Similarly, as shown inFIG. 7Afor example, one end of a center anchoring strap164adesirably is attached permanently at the middle of the front border strip64. As shown inFIG. 5Afor example, one end of a lower bracing anchor strap164cis attached to the rear border strip64and spaced at a distance halfway between where the center anchoring strap164ais attached and the bottom border strip63of the fencing panel61. The opposite end of this lower bracing anchor strap164cis attached to the free end of the center anchoring strap164a. As shown inFIG. 5Afor example, one end of an upper bracing anchor strap164dis attached to the rear border strip64and spaced at a distance halfway between where the center anchoring strap164ais attached and the top border strip62of the fencing panel61. The opposite end of this upper bracing anchor strap164dis attached to the free end of the center anchoring strap164a.

As shown inFIG. 7Afor example, one end of a lower bracing anchor strap164cis attached to the front border strip64and spaced a distance halfway between where the center anchoring strap164ais attached and the bottom border strip63of the fencing panel61. The opposite end of this lower bracing anchor strap164cis attached to the free end of the center anchoring strap164a. As shown inFIG. 7Afor example, one end of an upper bracing anchor strap164dis attached to the front border strip64and spaced a distance halfway between where the center anchoring strap164ais attached and the top border strip62of the fencing panel61. The opposite end of this upper bracing anchor strap164dis attached to the free end of the center anchoring strap164a.

As shown inFIGS. 5A and 7Afor example, the end of each of the center anchoring straps164aconnected to the respective lower and upper bracing straps164c,164ddesirably is connected to an attachment clip164bthat selectively can be attached and detached by hand to a respective eyelet26. As shown inFIG. 7Afor example, the attachment clip164bon the center anchoring strap164aconnected to the front border strip64desirably can be selectively attached and detached to the eyelet26that is connected to the rear side of the front anchoring post122. Similarly, as shown inFIG. 5Afor example, the attachment clip164bon the center anchoring strap164aconnected to the rear border strip64desirably can be selectively attached and detached to the eyelet26that is connected to the front side of a respective front leg31of the chassis30.

Each of the top border strips62, the bottom border strips63, the front and rear border strips64and the anchoring straps64a,164a.164c,164ddesirably is formed of a densely woven textile binding that desirably is made of synthetic thread such as polyester for example.

As shown inFIGS. 3, 9A and 9Bfor example, elongating from the front side of the upper end of each front leg31, there is a cylindrical guide rod59, which desirably is formed of a one inch inner diameter schedule40steel pipe with a domed cap welded to the free end to form the conical free end of the guide rod59. The opposite end of the guide rod59is connected to the upper portion of a front leg31and desirably elongates in a straight line in a horizontal direction that is parallel to the ground. As shown inFIGS. 5 and 5Afor example, this guide rod59elongates in a direction that is roughly coincident with the direction along which the upper cable54is to be extended when the upper cable54is deployed in the operational mode of the mobile fall protection unit20. The opposite end of the guide rod59is a free end that terminates conically to a point.

When not being deployed in an operative condition that is stretched along the length of a flatbed15, each respective fencing panel61desirably is stored in an accordion-like folded condition with the slide rings62acarried on a respective one of these guide rods59. As shown inFIGS. 5 and 5Afor example, a tie-back48desirably can be provided and anchored to the front leg31. When the fencing panel61assumes its accordion-like folded condition, this tie-back48can be used by the operator to restrain the bunched together fencing panel61against the respective front leg31. The weight of the fencing panel61with the attached rings62a, loops63aand other hardware is about fifty pounds.

FIG. 4depicts an enlarged perspective view of a lower winch51, which is attached, as by being mechanically bolted for example, to the base39aof a lower winch platform34a. One opposite end of a lower cable52is anchored to the spindle (not visible in the view ofFIG. 4) of the reel51aof the lower winch51. As shown inFIGS. 7 and 7Afor example, the opposite end of each lower cable52is the free end that is connected to an attachment clip52asuch as a carabiner clip that desirably is spring loaded in a closed mode but that selectively can be manipulated by the operator to the open mode for attachment to a suitable receptacle such as one of the rings24at lower end of each front anchor stanchion22or122.

In a presently preferred embodiment depicted inFIG. 2Afor example, each of the lower winches51is disposed so that the reel51ais offset to the outside edge (the edge facing away from the spinal member32) of the respective leg31so that there should be no more than one inch of the actual reel51asituated behind the respective leg31. In the embodiment shown inFIG. 2A, the lower winch51is positioned so that it fits flush with the side of the wider flatbeds15and is positioned so that the rub rail of the narrower flatbeds15will be spaced apart from the position of the lower winch51. In this way, the lower cable52spools off the reel51ato the outside edge of the respective leg31. As shown inFIG. 7Afor example, for the wider flatbeds15, this disposition of the reel51aof the lower winch51ensures deployment of the lower cable52alongside the rub rail of the flatbed15but not touching the rub rail. For the narrower flatbeds15, this disposition of the reel51aof the lower winch51ensures deployment of the lower cable52spaced a small distance away from the outside surface of the rub rail of the flatbed15. Thus, in both cases (whether narrower or wider flatbeds15), this position of the lower winch51ensures that the fencing panel61will be deployed leaving a gap between itself and the outer side edge of the flatbed15. That gap will be less than 19 inches for narrower flatbeds15and desirably less than six inches for wider flatbeds15but not so close as to allow the fencing panel61or the lower cable52to be touching either the outer side edge of the flatbed15or the tires that carry the flatbed15. Thus, in both cases (whether narrower or wider flatbeds15) in the presently preferred embodiment ofFIGS. 2A and 5A, this position of the lower winch51ensures that the lower cable52does not rub against either the tires that carry the flatbed15or the outer surface of the rub rail of the flatbed15. Similarly, as shown inFIGS. 2A, 4 and 5Afor example, each of the upper winches53also is disposed so that the reel53ais offset to the outside edge (the edge facing away from the spinal member32) of the respective leg31so that there should be no more than one inch of the actual reel51asituated behind the respective leg31and the upper cable54spools off the reel53ato the outside edge of the respective leg31.

As shown in an alternative embodiment ofFIG. 2for example, each of the lower winches51is disposed so that the reel51ais offset to the inside edge (the edge facing toward the spinal member32) of the respective leg31so that there should be no more than one inch of the actual reel51asituated behind the respective leg31. In the embodiment shown inFIG. 2, the lower winch51is positioned so that it fits flush with the side of the narrower flatbeds15and is positioned so that it fits inside of the rub rail on the wider flatbeds15. In this way, the lower cable52spools off the reel51ato the inner side edge of the respective leg31. As shown inFIG. 7for example, for the wider flatbeds15, this disposition of the reel51aof the lower winch51ensures deployment of the lower cable52beneath the underside of the outer side edge of the walking surface15aof the flatbed15. For the narrower flatbeds15, this disposition of the reel51aof the lower winch51ensures deployment of the lower cable52at least even with the outer side edge of the walking surface15aof the flatbed15. Thus, in both cases (whether narrower or wider flatbeds15) in this alternative embodiment depicted inFIGS. 2 and 5, this position of the lower winch51ensures that the fencing panel61will be deployed without leaving a gap between the fencing panel61and the outer side edge of the flatbed15. Similarly, as shown inFIGS. 2, 4 and 5for example, each of the upper winches53also is disposed so that the reel53ais offset to the inside edge (the edge facing toward the spinal member32) of the respective leg31so that there should be no more than one inch of the actual reel51asituated behind the respective leg31and the upper cable54spools off the reel53ato the inside edge of the respective leg31.

As shown inFIG. 4for example, each of the lower winch51and the upper winch53includes its own hand crank51b, which is moveable at the option of the operator to each of the three rotatable shafts56a,56band56cof the respective lower winch51and upper winch53. Each rotatable shaft56a,56band56ccan be rotated forward and backward and is geared to provide a different mechanical advantage with each rotation of the hand crank51b. For example, when the hand crank51bof the lower winch51is attached to the top shaft56a, which is connected directly to the spindle of the reel51a, each single complete rotation of the hand crank51bproduces a single complete rotation of the spindle and the reel51a, resulting in a1:1crank-to-reel rotation. Typically, this top shaft56ahaving the1:1crank-to-reel rotation would be chosen when the operator is rotating the reel51ain the backward direction (counterclockwise inFIG. 4) to wind up the lower cable52back onto the spindle of the reel51a.

In the view shown inFIG. 4, the hand crank51bis attached to the center shaft56b, which has one opposite end connected to a ratchet wheel51cand the other opposite end connected to a small diameter gear51d. Rotation of the center shaft56bvia the hand crank51brotates the small diameter gear51d, which in turn rotates the gear on the reel53aand thereby effects a 10:1 crank-to-reel rotation ratio. Thus, the operator must completely rotate the hand crank51bten times in order to effect a single complete rotation of the spindle and reel51a.

The bottom shaft56cis connected to yet another gear (not visible in the view ofFIG. 4) that is meshed with the ratchet wheel51cthat is mounted on the end of the center shaft56bin the foreground of the view ofFIG. 4and in so doing effects a 15:1 crank-to-reel rotation ratio. Rotation of the bottom shaft56cvia the hand crank51brotates the gear hidden from view, which in turn rotates the ratchet wheel51c, which in turn rotates the center shaft56band the small diameter gear51dat the opposite end of the center shaft56b, and this small diameter gear51din turn rotates the gear on the reel53aand thereby effects a 15:1 crank-to-reel rotational ratio. Thus, the operator must completely rotate the hand crank51bfifteen times in order to effect a single complete rotation of the spindle and reel51a. A fifteen-to-one mechanical advantage is not required to tighten the cable, and typically the operator would select the ten-to-one center shaft56b. Accordingly, though specifically illustrated inFIG. 4, there desirably will be a plastic cover secured over the fifteen-to-one bottom shaft56cthat prevents the operator from using the fifteen-to-one bottom shaft56cwhen adjusting the tautness of the cable52or54.

A conventional retention mechanism is provided to maintain the tension in the lower cable52and keep the reel51afrom free spooling when the operator's hand releases the hand crank51b. As shown inFIG. 4for example, this conventional retention mechanism can be provided in the form of a linkage57that includes a rod57ahaving each opposite end fixed against rotation to a respective one of the side plates of the lower winch51. A torsion spring57bis wound around the rod57awith one end fixed to the rod57aand an opposite end (not visible inFIG. 4) attached so as to bias a pawl (not visible in the view ofFIG. 4) into the hidden gear. When this pawl is engaged, it is inset into the hidden gear and only allows the hidden gear to rotate in one direction, which is the direction that allows the reel51ato rotate in the direction (counterclockwise inFIG. 4) that winds the lower cable52onto the spindle.

With the pawl engaged and the free end of the lower cable52attached to the front anchor post22near the bulkhead16of the flatbed15, every rotation of the hand crank51bin the clockwise direction inFIG. 4increases the tension on the lower cable52as the lower cable52winds onto the spindle of the reel51a, and the pawl prevents rotation of the spindle and the reel51ain the direction for unwinding of the lower cable52. Manual release of the pawl eliminates the tension on the lower cable52and allows the lower cable52to be unwound from the spindle of the reel51aof the lower winch51.

FIG. 4similarly depicts an upper winch53, which also is desirably is attached, as by being mechanically bolted for example, to the base of an upper winch platform34band operates with respect to the upper cable54in the same way as the lower winch51operates with respect to the lower cable52. Thus, the upper winch53similarly has its own conventional retention mechanism. Moreover, as shown inFIGS. 7 and 7Afor example, the free end of the upper cable54desirably terminates in an attachment clip54athat desirably is spring loaded in a closed mode but that selectively can be manipulated by the operator to the open mode for attachment to a suitable receptacle such as one of the loops25at upper end of each front anchor stanchion22or122.

As shown inFIGS. 9A and 9Bfor example, there desirably is a respective pulley58that is rotatably mounted at the upper end of each leg31. Each respective pulley58desirably is disposed within the hollow interior of a housing31athat is mounted atop the respective front leg31. The housing31adefines a front window31bthat is an opening into the hollow interior of the housing31a. Each pulley58is configured and disposed to carry the upper cable54so that when the mobile flatbed fall protection unit20is deployed in its operational mode against the rear end of the flatbed15, the upper cable54is tangentially taken off the pulley58in a direction that is toward the front end of the flatbed15where the bulkhead16(FIGS. 1 and 7) typically is to be found. The upper cable54is taken off the reel53aof the upper winch53(FIG. 4) and threaded around the pulley58and then through the front window31bof the pulley housing31a(FIGS. 9aand9B) and pulled toward the front of the flatbed15.

One exemplary manner of deploying a mobile flatbed fall protection unit20in its operational mode now will be described. Though none of the figures depicts this pre-operational mode of the mobile fall protection unit20as such, when in this pre-operational mode the mobile flatbed fall protection unit20has each respective fencing panel61hanging by its respective upper slide rings62afrom a respective one of the guide rods59and secured by a respective tie-back48to the respective front leg31. As shown inFIG. 3for example, the two front anchor stanchions22are held in their respective stanchion pockets21carried on the spinal member32. To avoid unduly cluttering the view,FIG. 2Aonly shows one of the two front anchor stanchions122is held in its stanchion pocket21carried on the spinal member32.

As shown inFIG. 4for example, the lower cables52and the upper cables54are wound around their respective reels51a,53aof their respective lower and upper winches51,53carried by each respective front leg31. What is not shown explicitly inFIG. 4is the fact that the lower cable52will always remain threaded through the loops63athat are attached permanently to the bottom border strip62of the fencing panel61. Similarly, the upper cable54desirably will always remain threaded through the rings that are attached permanently to the top border strip62of the fencing panel61. In this storage mode of the fencing panel61before being deployed in operation along one of the sides of a flatbed15, the attachment clip52aat free end of lower cable52can be hooked onto the lower winch51to restrain the lower portion of the fencing panel61out of harm's way. Similarly, in this storage mode of the fencing panel61, the attachment clip54aat the end of the upper cable54can be hooked onto one of the eyelets26that is connected to the front side of a respective front leg31of the chassis30.

The mobile chassis30of the mobile flatbed fall protection unit20is disposed a at one end of the support member (walking surface15a) of the flatbed15with the pair of legs31spaced apart widely enough to dispose one leg31by one of the sides of the support member15and the other leg31by the other one of the sides of the support member15. The operator desirably uses the handle40to maneuver the mobile flatbed fall protection unit20on its wheels36a,36bto a location with its frame50against the rear end of the flatbed15and its legs31disposed to either side of the flatbed15as shown inFIGS. 1, 5 and 5Afor example. Then the operator sets each respective tie strap45on each respective side of the flatbed15by extending the tie strap45from the respective length-adjustable tensioning device47carried on the respective front wheel carriage35and using the hook on the free end of the tie strap45to anchor the tie strap45to the side of the flatbed15as shown inFIGS. 5 and 5Afor example.

When the operator decides to deploy one of the fencing panels61along one side of the flatbed15, the operator normally will begin the process by removing one of the front anchor stanchions22or122from the stanchion pocket21on the spinal member32of the chassis30and attach the attachment clip54aat free end of upper cable54to the loop25at rear edge of the upper end of front anchor stanchion22or122. In this way, the operator can attach the upper cable54to the upper end of front anchor stanchion22or122without stretching or standing on a ladder or step stool. The operator then ensures that the pawls of the linkages57on both the lower winch51and the upper winch53as shown inFIG. 4for example are disengaged to allow the respective lower cable52and upper cable54to be spooled off the respective reel51a,53a. With the upper cable54attached to the upper end of front anchor stanchion22or122, the operator will walk to the front of the flatbed15and insert the ringed end of the front anchor stanchion22or122through the forward most stanchion pocket17at or near the bulkhead16at the front end of the flatbed15as shown inFIGS. 1, 7 and 7A. By inserting the bottom end of this front anchor stanchion22into a stanchion pocket17at that location on the flatbed15, the operator anchors this front anchor stanchion22to the flatbed15. Thus, as shown inFIGS. 7 and 7Afor example, an upper section of this front anchor stanchion22or122extends vertically above the elongated support member15aof the flatbed15and a respective lower section22aor122aextends vertically beneath the elongated support member15aof the flatbed15.

Desirably, as shown inFIGS. 7 and 7Afor example, the operator would attach one end of a tie strap45fitted with a length-adjustable tensioning device47to the respective front anchoring loop27or127of the respective front anchor stanchion22or122and the hook46at the opposite end of the tie strap45to the side of the flatbed15. As shown inFIG. 7A, the front anchoring loop127of the front anchor stanchion122is desirably attached to the one end of the tie strap45by a loosely hanging closed belt127a. In this way, the operator can reach the free end of the belt127awhile standing on the ground and so can attach the tie strap45without standing on a ladder or step stool or climbing onto the support surface15aof the flatbed15. While the belt127ais shown inFIG. 7Aas hanging loosely downward under the weight of the tensioning device47and the tie strap45, when the tensioning device shortens the deployed length of the tie strap45, then the belt127awill be rendered under tension and its tensioned length disposed at an acute angle from the front anchor stanchion122.

Then, the operator unhooks the attachment clip52afrom the lower winch51, grabs the free end of the lower cable52and pulls the lower cable52to the front anchor stanchion22or122where the clip52ais secured into the bottom anchoring ring24at the lower end of the front anchor stanchion22or122as shown inFIG. 7 or 7Afor example. Now both the upper cable54with the attachment clip54aand the lower cable52with the attachment clip52aare attached to the front anchor stanchion22or122as shown inFIG. 7 or 7Afor example. As shown inFIG. 4for example, the operator then ensures that the pawls of the linkages57are engaged on both of the lower winch51and the upper winch53.

The operator selectively secures one end of the fencing panel61to the chassis30. As shown inFIG. 5A, the operator can manually connect the attachment clip164bof the rear border strip64to the eyelet26that is attached to the front leg31. Alternatively, as shown inFIG. 5, the operator can manually connect each attachment clip64bof the rear border strip64to a respective one of the eyelets26that is attached to the front leg31. In this way, one end of the fencing panel61is selectively secured to the chassis30by being selectively secured to one of the legs31of the chassis30. When the operator decides to deploy the fencing panel61, the operator can release the tie-back48restraining the fencing panel61to the front leg31. The operator then pulls the front border strip64of the fencing panel61away from the storage rod59on the front leg31and to the front anchor stanchion22. In this way, the operator then deploys a fencing panel61lengthwise between the chassis30and one of the rigid front anchor stanchions22or122and height-wise between the upper cable54and the lower cable52.

Though only one fencing panel61is depicted in the view shown inFIG. 1, each respective fencing panel61on each respective side of the fall protection unit20can be stretched out to its full length and deployed along one of the two respective sides of the flatbed15. Each fencing panel61can be pulled manually along the respective lower cable52and the respective upper cable54and deployed along one respective side of the flatbed15. The operator then selectively secures one end of the fencing panel61to one of the rigid front anchor stanchions22or122. As shown inFIG. 7Afor example, the operator can manually connect the attachment clip164bof each respective front border strip64to the eyelet26that is attached to the rear side of the front anchor stanchion122. Similarly, as shown inFIG. 7for example, the operator can manually connect each respective attachment clip64bof each respective front border strip64to a respective one of the eyelets26that is attached to the rear side of the front anchor stanchion22.

As shown inFIGS. 1, 3 and 6for example, one of the vertically elongating rigid posts held in one of the two stanchion pockets21disposed on each side of the spinal member32desirably is a center guide stanchion23. As shown inFIG. 3for example, the lower section23aof each center guide stanchion23is configured to be received easily and snugly into one of the two stanchion pockets21. As shown inFIG. 6for example, the lower section23aof each center guide stanchion23is configured to be received easily and snugly into a stanchion pocket17that conventionally is formed in the side of the flatbed15in the vicinity of the midpoint along the length of the flatbed15. A stop collar28desirably is attached at one end of the lower section23aof the center guide stanchion23and is configured and disposed so as to prevent the further descent of the center guide stanchion23into one of the stanchion pockets17typically found in the side of the flatbed15or one of the stanchion pockets21carried on the side of the spinal member32of the chassis30.

As shown inFIG. 6for example, at the upper end of each center guide stanchion23, a cable guide29is configured to selectively receive therein an upper cable54. This cable guide29desirably defines a tubular configuration that is open at both axially opposite ends and that includes a slot29athat elongates for the entire axial length of the cable guide29. The slot29apermits the upper cable54to be inserted manually into the cable guide29or manually removed from the cable guide29without having to thread the free end of the upper cable54in one end of the cable guide29and out the opposite axial end of the cable guide29.

The operator then would remove a center guide stanchion23from its respective stanchion pocket21on the spinal member32of the chassis30and walk to about the middle of the flatbed15as shown inFIGS. 1 and 6for example. There the upper cable54would exhibit its maximum sag under the weight of the upper cable54and the fencing panel61. The operator then would insert the upper cable54into the cable guide29at the upper end of the center guide stanchion23. Accordingly, the operator would manipulate the upper cable54through the slot29aand into the cable guide29that is formed in the upper end of the center guide stanchion23. The operator then would anchor this center guide stanchion23at or near the midpoint between the rear of the flatbed15and the bulkhead16by inserting the lower section23aof this center guide stanchion23into a central stanchion pocket17at that location on the flatbed15as shown inFIG. 6for example. Thus, the middle of the upper cable54will be supported in the cable guide29and thus compensate for the tendency of the upper cable54to sag towards the middle of the fully extended length of the upper cable54. The rigid center guide stanchion23that is anchored at or near the midpoint between the rear of the flatbed15and the bulkhead16at the front end of the flatbed15as shown inFIG. 6also aids in reducing deflection of the upper cable54and fencing panel61if someone were to fall against the fencing panel61when fully deployed along the respective side of the flatbed15.

Once the fencing panel61is fully deployed as shown inFIG. 1and secured between the front leg31and the front anchor stanchion22or122with the center guide stanchion in place, the operator then can use the length-adjustable tensioning device47to pull the front anchor stanchion22or122toward the bulkhead16of the flatbed15and thus support the front anchor stanchion22or122in a way that tends to reduce the strain on the front anchor stanchion22or122that otherwise would be imposed by the upper cable54, the upper winch53and the weight of the fencing panel61.

Then by operating the hand crank51bon the lower winch51and the upper winch53, the operator can set the desired tension in both the lower cable52and the upper cable54. Thus, the operator uses the lower winch51to render the lower cable52taut between the lower winch51and the lower section22aof the at least one rigid stanchion22and similarly uses the upper winch53to render the upper cable54taut between the upper winch53and the upper section of the at least one rigid stanchion22.

When the work on the flatbed15has been completed, the fencing panels61, the lower cables52and upper cables54, the center guide stanchions23and the front anchor stanchions22can be restored to their respective storage positions by reversing the deployment steps outlined above.

As shown inFIGS. 2, 2A and 3for example, the mobile fall protection unit20desirably provides a second type of selectively deployable fall protection device, which includes fence posts67that are permanently affixed to the frame50. Desirably, the position of each fence post67between the front legs31is maintained in a fixed location. As shown in the presently preferred embodiment depicted inFIG. 2Afor example, the bottom end of each fence post67desirably is welded to the rear side of the frame50. As shown in an alternative embodiment depicted inFIG. 2for example, the bottom end of each fence post67is bolted to the rear side of the frame50.

As shown inFIGS. 2 and 2Afor example, a plurality of eyelets67ais carried by and connected to each opposite side of each respective fence post67. As shown inFIGS. 2 and 2Afor example, an eyelet67atypically will be positioned on at least one of the opposite sides near the top of each fence post67and on at least one of the opposite sides near the midpoint of each fence post67. Each of the fence posts67desirably will have a pair of the eyelets67apositioned on each of the opposite sides near the top of each fence post67and on opposite sides near the midpoint of each fence post67. As shown inFIG. 3for example, each front leg31desirably will have side eyelets31cspaced along the length thereof and disposed generally at the same heights to coincide with the eyelets67apositioned on each of the opposite sides of each immediately adjacent fence post67.

As shown inFIGS. 2 and 2Afor example, the second type of selectively deployable fall protection device desirably includes a plurality of chains68that desirably are made of links, which desirably can be formed of zinc-plated steel but also can be formed of galvanized steel. Each chain68can be provided for extending between and connected to the pair of fence posts67. Each opposite free end of each chain68desirably is provided with a manually operative latching link68athat can be selectively connected to as well as disconnected from an eyelet67aon one of the fence posts67. A carabiner clip serves as a suitable latching link68a. In this way, the fence posts67and chains68provide fall protection from the rear of the flatbed15.

As shown inFIGS. 1-3for example, embodiments of the mobile fall protection unit20desirably can include a ladder70carried by the frame50at the front of the chassis30and disposed between the two front legs31. As shown inFIGS. 2 and 2Afor example, the ladder70includes a pair of side rails72and a plurality of rungs71that desirably are configured as cylindrical rods. One end of each rung71is connected to a respective one of the pair of side rails72, which are disposed parallel to each other and spaced apart from each other and extend vertically at a slight acute angle from the vertical direction of the force of gravity. As shown inFIGS. 1, 2 and 2Afor example, the top rung is provided in the form of a flat step71athat extends horizontally between the side rails72.

Additionally, as shown inFIGS. 2, 2A and 3for example, the ladder70desirably is provided with a pair of spaced apart handrails75that extend and elongate above the flat step71a. Each handrail75extends vertically from the flat step71ain a direction that is parallel to the direction in which the other handrail75extends so that the worker can grab the handrails75when ascending or descending the ladder70. As shown inFIGS. 2 and 2A, the section of each respective handrail75that is located just above the bottom free end75ais configured to be received through the flat step71a. As shown inFIG. 2for example, a collar desirably75bcan be securely connected to both that section of the handrail75and the flat step71a, as by being welded to both. Thus, as shown inFIG. 3for example, the bottom free end75aof each respective handrail75extends beneath the flat step71a.

As shown inFIGS. 2-4for example, the frame50desirably includes a first pair of spaced apart holding sleeves55attached to the frame50at a first side of the frame. Similarly, the frame50desirably includes a second pair of spaced apart holding sleeves55attached to the frame50at a second side of the frame50that is opposite the first side of the frame50. Desirably, each pair of holding sleeves55is located between one of the legs31and the nearest fence post67to that leg31. Each holding sleeve55desirably defines a tubular cavity that is open at both opposite ends. In the embodiment shown inFIGS. 2 and 2Afor example, the openings and tubular cavity of each holding sleeve55desirably has a rectangular transverse cross-sectional shape that is complementary with the exterior transverse cross-sectional shape of the bottom free end75aof a handrail75of a ladder70and thus is configured to receive snugly therein the bottom free end75aof a handrail75of the ladder70.

Thus, the handrails75and the flat step71aconnected to the handrails75of the ladder70are configured so as to permit the ladder70to be carried by and hung from the frame50at the front of the chassis30so that the workers can ascend the ladder70from the ground to the walking surface15aof the flatbed15and descend the ladder70from the walking surface15aof the flatbed15to the ground. As shown inFIGS. 2 and 2A, each respective handrail75is configured with a respective the bottom free end75athat slides into a holding sleeve55from above the rear of the frame50. The bottom free ends75aof the handrails75depending below the flat step71aalso permit the ladder70to be easily detachable from the frame50by lifting the handrails75and sliding the bottom free ends75aout of the holding sleeves55from above the frame50. As there is one pair of holding sleeves55disposed near each opposite end of the frame50, the ladder70can be selectively positioned by the operator near either opposite end of the rear of the frame50. Thus, the ladder70and the frame50are configured so that the ladder70can be carried by the frame50and selectively moveable transversely along the frame50.

As shown inFIGS. 2 and 2Afor example, there is a respective pivotal connection70abetween the top end of each respective side rail72and a lower end of a respective handrail75. As shown inFIGS. 2, 2A and 4for example, located just above the collar75bthat connects each handrail75of the ladder70to the flat step71a, there is a section of each handrail75to which a hinge plate75cis attached, as by welding. Each of these hinge plates75cis pivotally attached via the respective pivotal connection70ato the upper end of a respective one of the side rails72of the ladder70. As shown inFIGS. 2 and 2Afor example, each of the hinge plates75cdesirably is formed by a triangular-shaped plate that has one of its sides attached, as by welding, to the handrail75.

Thus, the side rails72of the ladder70desirably are pivotally mounted to the handrails75so that the ladder70can be deployed selectively as a step ladder from the ground to the height of the walking surface15aof the flatbed15as shown inFIG. 2for example. As shown inFIG. 3for example, when the mobile flatbed fall protection unit20is not being used, the pivotally mounted side rails72of the ladder70desirably can be selectively folded up off the ground for storage parallel to the handrails75between one of the front legs31and one of the fixed fence posts67. A latch such as a gate style latch (not shown) desirably is provided so that when the latch is engaged, then one of the side rails72can be held fixed with respect to one of the handrails75of the ladder70to retain the ladder70in the stored position as shown inFIG. 3for example.

While at least one presently preferred embodiment of the invention has been described using specific terms, such description is for illustrative purposes only, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the following claims. This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.