Abstract:
A portable safety ladder assembly having safety extensions to permit safe and easy access to landing areas, working platforms, scaffolds, etc. The safety extension members have a plurality of horizontal handgrips ergonomically designed to prevent falls from the ladder assembly when a user is ascending upward or descending downward thereon.

Description:
CROSS REFERENCE TO PRIOR APPLICATIONS 
     The present application is a continuation of U.S. patent application Ser. No. 11/679,164 filed Feb. 26, 2007 (now U.S. Pat. No. 7,992,681), which is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     A portable safety ladder assembly having safety extensions members used in combination therewith to permit safe and easy access to a landing area, working platform or scaffold. Particularly, the portable safety ladder includes stowable safety extensions to thereby provide safe and convenient access to working platforms and includes a pair of safety extension members having horizontal handgrips or grab bars that enable a user to safely walk up or down the ladder. 
     2. Description of the Related Art 
     Occupational injuries resulting from ladder falls are a known hazard, especially for vehicles having flatbeds such as dock-height and drop-deck flatbed trailers and railcars, especially (but not limited to) those with head racks. Such falls result as the operator and/or driver is attempting to ascend or descend the flatbed, therein resulting in a disabling injury or even death. The Bureau of Labor Statistics (BLS) records for falls from non-moving vehicles show upwards of approximately 15,000 fall injuries per year. Moreover, access to the working surface of the flatbed poses significant risk of falling to the ground without a firmly installed flatbed ladder. Also, falls from ladders is one of the top three causes of occupational fatalities according to BLS statistics. Previously, access by ICC rail, a wheel rim or from cab to trailer transfer to access a flatbed having a height of approximately five feet or alternatively using a step ladder which can easily tip over and is unstable. 
     One prior art attempt for reducing ladder falls in a trucking application is providing a plurality of steps welded to the frame of a transport vehicle. This method, however, still places the driver and/or operator at risk when ascending up or descending down the ladder (again, especially when the trailer has a head rack that must be climbed around). 
     Furthermore, since tractors and trailers are sometimes interchangeable, operators will not always have the aforementioned steps available to them (even owner-operators who may be forced to use a rental tractor at times). Consequently, many drivers carry a portable step ladder strapped to the rear of the sleeper portion of the tractor. Often times, however, such portable step ladders are not utilized due to the inconvenience of deploying them when needed. Moreover, the base or feet of such prior art ladders are unstable, in particular, they are prone to inadvertent displacement or shifting from the support area on the ground surface when a user is ascending up or descending down the ladder. The base is also susceptible to slipping in hazardous surface conditions such as rain, snow, ice, etc., and thus, causes the ladder to move and/or topple over. 
     Another manner of ascending up or descending down the ladder to access a working platform of a flatbed trailer is by climbing up the rim and/or tire of the trailer (or the tractor, whose wheels are under the trailer). This manner, however, is extremely dangerous, especially when hazardous weather conditions such as rain, snow, ice, etc., are present. 
     Some prior art ladders include attachments permitting a user to access a landing area of a roof or other structure. Such attachments are secured at a distal end opposite the base of the ladder and include a pair of parallel vertical side rails or bars used as handrails for grasping by the user when access to the landing area is required. 
     The aforementioned design, however, has serious ergonomic drawbacks that lack adequate safety protocols to the user. For instance, such ladders lack any stability control that securely anchors the ladder against a vertically surface such as a wall to and prevent forward and/or lateral displacement of the ladder away from a support area on the ground. 
     Moreover, the use of vertical handgrips does not permit the user to adequately use a power gripping orientation of the hands required to maintain balance without slipping when falling backwards away from the front face of the ladder. Even still, if a power grip is used, it is nonetheless ineffective in the occurrence of a fall from the ladder since a slide of the user&#39;s hands will precede out of control, thus causing the user to fall to the ground as a result of the impact load from body&#39;s weight. 
     The configuration and size of the vertical grab bars also make it impossible for a user to encircle them by hand. As a result, the hand cannot form adequate gripping power necessary to withstand an impact load of the body if the user slips or loses balance. Accordingly, a “pinch grip” must be used which makes fall safety virtually impossible to achieve. Moreover, the spatial distance between the upper gripping area of the vertical handgrips and the walk through area is ergonomically problematic insofar as it requires the user to assume an unnatural, unsafe and uncomfortable bending position when ascending to the landing area from the ladder or transitioning from the landing area to the ladder. Such bending may actually result in the user falling from the ladder and/or the working platform. 
     Lastly, the prior art ladders lack the ability to have a user safely ascend/descend from the ladder using 3-point control, i.e., with two feet on the ladder or the ground and one hand one the ladder, or with two feet on the handgrips handles and one foot on the ladder. Any such attempt at three point control will result in the ladder tipping over and/or the user losing balance on the ladder and falling therefrom. 
     Accordingly, there is a very pressing need to mitigate or otherwise reduce the number of deaths and injuries resulting from falls from a ladder. 
     SUMMARY OF THE INVENTION 
     In view of the foregoing, it is an object of the present invention to provide a portable safety ladder assembly and a safety extension which permits a user to safely and quickly enter and leave a working platform/landing area of a structure or vehicle such as the flatbed of a transport vehicle or railcar. 
     It is another object of the invention to provide a portable safety ladder assembly ergonomically designed to mitigate or otherwise reduce various occupational injuries and/or deaths by acting as a fall arrest system capable of supporting an impact load from the body of the user in the occurrence of a user falling therefrom. 
     It is yet another object of the invention to provide a stowable portable safety ladder assembly sized for compact and convenient stowing. 
     It is a further object of the invention to provide a portable safety ladder assembly having removable safety extensions that are quickly and easily moveable between operative/inoperative positions on the side frames of the ladder and a storage position on the front and rear ends of the ladder. 
     It is still another object of the invention to provide a portable safety ladder assembly that may be securely anchored to a surface of a structure, vehicle and the like to prevent forward and/or lateral shifting or displacement (i.e., movement in directions parallel and/or perpendicular to the outer peripheral surface) of the ladder when placed in an operable position. 
     It is yet another object of the invention to provide a safety ladder extension having a plurality of horizontally oriented handgrips permitting a user to safely ascend/descend from a working platform or surface of a structure or vehicle, even under hazardous surface conditions such as rain, ice, snow, etc. 
     Another object of the invention is to provide a portable safety ladder assembly having safety extension members that are vertically and rotationally moveable relative to the ladder between operative and inoperative positions. 
     Still another object of the invention is to provide a portable safety ladder assembly having safety extension members that lie at the same angle and also in the same plane as the ladder when the assembly is leaned against an intended structure or vehicle. 
     Yet another object of the invention is to provide a safety ladder extension having horizontally extending handgrips and vertical poles forming a unique configurative array permitting a user to maintain a continuum of grips when ascending/descending from a ladder, even under hazardous surface conditions such as rain, ice, snow, etc. 
     Still an additional object of the invention is to provide a portable safety ladder assembly having safety extension members that when placed in an operative position is elevated above the working surface to a height permitting a user to stand at a substantially erect position (i.e., not a bending position) when transitioning from the ladder&#39;s walk-through section. 
     Yet and still another object of the invention is to provide a portable safety ladder assembly that permits three-point control by the user, i.e., the ability to safely ascend/descend from the ladder with two feet on the ladder/on the ground and one hand on the ladder, or two feet on the handles and one foot on the ladder. 
     Yet an additional object of the invention is to provide a safety extension a safety ladder extension having horizontally extending handgrips and vertical poles forming a unique configurative array permitting a user to use either a power- or hook-type handgrip that withstands impact loads from the user&#39;s body during the occurrence of a fall backwards by the user. 
     These, as well as other objects and characteristics of the present invention may be achieved in accordance with an aspect of the invention which includes a portable safety ladder assembly including a main ladder section or frame having a distal end including a walk-through area, a base end opposite the distal end which engages a base surface to provide an area of support for the assembly when the assembly is placed in an operable position against the outer peripheral frame, a pair of parallel side rails connected by a plurality of horizontal rungs, a front section from which a user engages the rungs when traversing up and down the assembly, and a rear section opposite the front section that is positioned proximate the outer peripheral frame, a first safety extension member provided on a respective one side rail and a second safety extension member provided on a respective other side rail, each of the safety extension members having first, second, third and fourth parallel horizontal handgrips, the handgrips being connected in an array such that the first and second horizontal handgrips are connected by a first outer vertical side pole, the second and third horizontal handgrips are connected by a second inner vertical side pole and the third and fourth horizontal handgrips are connected by a third outer vertical side pole, wherein the first horizontal handgrip is spaced above and proximate the walk-through section and the fourth horizontal handgrip is spaced above the walk-through a distance permitting the user to stand substantially erect when accessing the working platform. 
     Yet other objects and characteristics of the present invention may be achieved in accordance with another aspect of the invention which includes a portable safety ladder assembly having the main ladder section and safety extension set forth hereinabove, and also a stabilizing mechanism for securably anchoring the main ladder section to a surface and preventing at least one of forward and lateral displacement of the main ladder section away from a support area. 
     Still other objects and characteristics of the present invention may also be achieved in accordance with a further aspect of the invention which includes a portable safety ladder assembly having the main ladder section and safety extension set forth hereinabove, and also a coupling mechanism mounted on the side ends for removeably receiving a respective the leg portion in a manner such that the safety extension members and the main ladder lie in substantially the same plane when the assembly is placed in the operable position. 
     Yet and still other objects and characteristics of the present invention may also be achieved in accordance with an additional aspect of the invention which includes a portable safety ladder assembly having the main ladder section and safety extension set forth hereinabove and a storage mechanism mounted on the front and rear ends for removeably storing the safety extension members on the main ladder when the assembly is in an inoperable position. 
     Yet further objects and characteristics of the present invention may also be achieved in accordance with an aspect of the invention which includes a portable safety ladder assembly having the main ladder section, safety extension, stabilizing mechanism and coupling mechanism set forth hereinabove. 
     Still further objects and characteristics of the present invention may also be achieved in accordance with an aspect of the invention which includes a portable safety ladder assembly having the main ladder section, safety extension, coupling mechanism and storage mechanism set forth hereinabove. 
     Yet and still further objects and characteristics of the present invention may also be achieved in accordance with an aspect of the invention which includes a portable safety ladder assembly having the main ladder section, safety extension, coupling mechanism, storage mechanism and stabilizing mechanism set forth hereinabove. 
     Yet additional objects and characteristics of the present invention may be achieved in accordance with an additional aspect of the invention which includes a safety extension in combination with a ladder having a pair of side rails connected by a plurality of spaced rungs, the safety extension having a pair of safety extension members each provided on a respective side rail, each of the safety extension members having, a leg portion adapted for connection to a respective side rail in a manner such that the safety extension members and the ladder lie in substantially the same plane when the assembly is placed in a position accessible by a user, and first, second, third and fourth parallel horizontal handgrips, the handgrips being connected in an array such that the first and second horizontal handgrips are connected by a first outer vertical side pole, the second and third horizontal handgrips are connected by a second inner vertical side pole and the third and fourth horizontal handgrips are connected by a third outer vertical side pole, the first horizontal handgrip being spaced above and proximate the walk-through section while the fourth horizontal handgrip being spaced above the walk-through a distance permitting the user to stand substantially erect when traversing through the walk-through section. 
     Still additional objects and characteristics of the present invention may be achieved in accordance with an additional aspect of the invention which includes a method of accessing a landing area which includes the steps of providing a ladder having at a distal end thereof a walk-through area, providing a pair of safety extension members coupled to the ladder such that each safety extension member and the ladder lie in substantially the same plane, such safety extension members having a plurality of parallel horizontal handgrips connected by inner and outer vertical side poles, wherein the upper most horizontal handgrip is spaced above the walk-through section a distance permitting a user to stand substantially erect when accessing the landing area, positioning the ladder to an operable position against a surface area, traversing up the ladder and engaging the horizontal handgrips once the walk through area is reached to access the landing area. 
     Accordingly, the safety ladder assembly set forth herein extends numerous advantages in its portability and adaptability to facilitate quick and easy transfer of the user to a working surface (landing) while mitigating or otherwise greatly reducing the threat of occupational hazards that have heretofore have caused death or serious physical harm. Further advantages extending from practice of the invention may be achieved by a safety ladder that is easily stowable and quickly and efficiently assembled/disassembled on site. Also advantageous is a safety ladder extension having horizontally extending handgrips and vertical poles forming a unique configurative array permitting a user to maintain a continuum of grips when ascending up or descending down the ladder, even under hazardous surface conditions such as rain, ice, snow, etc. Such an array is also ergonomically efficient in permitting the user to employ either a power- or hook-type handgrip that withstands impact loads from the user&#39;s body during the occurrence of a fall backwards by the user. The array also permits the user to access the working platform from the walk-through area of the ladder in a natural exiting position, particularly, in a substantially erect position (i.e., not bend downwardly), when ascending/descending from the ladder. 
     Advantages of the invention may also be derived from a safety ladder assembly having a pair of safety extensions that are rotationally and releasably connectable to the main ladder section to provide ease in assembly, storage and transfer. Further advantageous of the invention may also be derived from a safety ladder assembly having a mechanism for securely stabilizing the assembly against the outer periphery of a surface, thereby preventing falls resulting from inadvertent forward and/or lateral shifting or displacement of the ladder from a support area. Such a stabilizing feature also maintains the assembly at the support area even in hazardous ground conditions such as rain, snow, ice and the like. 
     These and other objects, features and advantages of the invention will become more apparent from the following description when taken in conjunction with the detailed drawings that show, for purposes of illustration only, the preferred embodiments of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The advantages of the invention will become more apparent to those skilled in the art in conjunction with the detailed description of the preferred embodiments, in which: 
         FIG. 1  is a perspective view of a user utilizing the portable safety ladder assembly towards the landing area of a flatbed trailer vehicle; 
         FIG. 2  is a frontal view of a portable safety ladder assembly in an operable or user-ready position; 
         FIG. 3  is a frontal view of a safety extension member; 
         FIG. 4  is a side view of the coupling mechanism and the stabilizing mechanism; 
         FIG. 5  is a frontal view of a portable safety ladder; 
         FIG. 6A  is a frontal view of a portable safety ladder assembly with a safety extension member in a storage position on the front end of the ladder frame; and 
         FIG. 6B  is a frontal view of a portable safety ladder assembly with a safety extension member in a storage position on the rear end of the ladder frame. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     As illustrated in the drawing figures, provided herein is a portable safety ladder assembly  10  including a ladder  20  and a safety extension  30  for permitting a user to have safe access to a working platform of an intended structure such as a flatbed trailer, rail car and the like. The safety ladder assembly  10  or the safety extension  30  are not limited to use solely with flatbed trailers or railcars, and may be used for non-trailer purposes and various applications requiring access to any landing area, working platform, scaffold and the like. 
     As shown in  FIG. 1 , the ladder  20  includes a walk-through section  21  at a distal, uppermost end, a base end  22  which contacts and engages a base surface, e.g., the ground, to provide an area of support for the assembly  10  when placed in an operable position. The ladder  20  also includes a pair of parallel side rails  23  connected by a plurality, i.e., more than two, of horizontal rungs  24 , a front section  25  directly facing wherein which a user may access and engage the rungs  24 , and a rear section  26  lying proximate the outermost peripheral surface of the frame of the intended structure or vehicle when the assembly  10  is placed in a user ready position. Preferably, the width of each rung  24  is about sixteen inches, the space between each rung  24  is preferably about twelve inches and the width of the walk-through section  21  is preferably about eighteen inches. The width of each rung and the spacing between rungs, however, is not limited to any particular size and thus, may be of any size or range of sizes permitting access to a working platform or landing area. 
       FIGS. 2 and 3  illustrate a safety extension  30  which includes a pair of safety extension members  31  removeably attached to the ladder  20  by collars  27 ,  28 . Each safety extension member  31  includes a lower section which attaches to the side rails  23  of ladder  20  which permits a user to safely access a working platform. Each safety extension member  31  has a lower section including a support pole or leg  32  and an upper section including a plurality of spaced, parallel horizontal handgrips  33  connected by vertical poles  34  in a unique configurative array permitting the user to maintain a continuum of grips when moving up or down the ladder  20 . The space between each handgrip  33  preferably coincides with the spacing between rungs, i.e., about twelve inches. The uppermost handgrip  33  is preferably spaced a distance of about three and one-half feet above the walk-through section  21  to enable the user to stand substantially erect, i.e., not bend over, when either ascending up or descending down the ladder. The spacing of the handgrips is not limited to any particular size, and thus, may vary. Moreover, while a plurality of horizontal handgrips  33  are shown herein, the invention is not limited to a plurality, and thus, may include one or two handgrips, preferably spaced a distance from the walk-through area that permits safe use of the assembly  10  in a similar manner as having a plurality of handgrips. 
     As shown in  FIG. 4 , a stabilizing mechanism  40  is provided to anchor or otherwise stably secure the ladder  20  to a substantially vertically extending surface of a structure or vehicle at a specific contact or engagement area. In essence, the stabilizing mechanism  40  serves to stabilize the ladder  20  as it leans against a vertically extending surface of an intended structure or vehicle while preventing forward and/or lateral shifting or displacement of the ladder  20  away from a support area on the ground surface, even in hazardous surface conditions such as snow, rain, ice, etc. Such a mechanism includes a C-shaped clamp or bracket  41  attached by bolts or comparable means to the rear section  26  of the ladder  20  for engaging, abutting or otherwise contacting at least the upper surface and outer peripheral contact areas of the frame of the intended structure or vehicle. The bracket  41  includes a base  42  connecting a pair of parallel arms extending from the base  42  in a direction substantially parallel to the ground surface including an upper arm  43  and a lower arm  44  to form a modular unit sized to receive and engage both the front, upper and lower surfaces of the intended contact surface. It should be noted that the size of the brackets  41  is not limited to any particular size, and thus, may vary depending on the application. Moreover, while a single bracket  41  is shown, practice of the invention is not limited to use of a single bracket, and thus, may encompass a stabilizing mechanism  40  having two or a plurality of brackets  41 . It should be further noted that the stabilizing mechanism  40  may be retrofitted to existing ladders and/or provided on ladders without safety extensions. 
     For those applications requiring use of the assembly  10  to access the working platform  110  of the flatbed of a trailer, as illustrated in  FIG. 1 , the bracket  41  is also adapted to engage, abut or otherwise contact the tie down rail  120  on the frame of the flat bed. An alternative embodiment for flatbed trailer applications is a stabilizing mechanism  40  encompassing a pair of C-shaped clamps or brackets  41   a  positioned on the outer peripheral edge of the flatbed frame. Each bracket  41   a  includes a base  42   a  connecting a pair of parallel arms extending from the base  42   a  substantially parallel to the ground surface including a left arm  43   a  and a right arm  44   a  forming a modular unit sized to receive and engage both the front, inner and outer surface areas of the of a respective side rail  23 . The brackets  41   a  are preferably moveable between a first position within an annular space or compartment within the frame  120  and a second position in which the brackets  41   a  extend or otherwise protrude from the frame  120  when the assembly  10  is placed in an operable position. The brackets  41   a  may be retractable or spring-loaded to enable movement from an inoperable, storage position to an operable position. While a stabilizing mechanism  40   a  having two brackets  41   a  is illustrated herein, practice of the invention is not limited to any particular number of brackets  41   a , and thus, may include a single bracket sized to receive to both front and outermost surface areas of each side rail  23 . 
     As illustrated in  FIG. 5 , attached by bolt or comparable means to the outermost peripheral surface of each side rail  23  is a pair of cylindrical-shaped mounting collars  50  including an upper collar  51  and lower collar  52  which permit removable coupling of the safety extension  30  to the ladder  20 . The upper collar  51  is located proximate the walk-through area  21  while the lower collar  52  is spaced therebelow towards the base end  22  of the ladder  20 . The collars  51 ,  52  each have an annular channel  53  therein sized to receive the lower support leg  32  of the safety extension members  31  while the lower collar  52  further includes a stop member  54  at a lowermost portion thereof which abuts, contacts or otherwise engages the bottommost portion of the support leg  32  once inserted therein. 
     As shown in  FIG. 2 , each support leg  32  is insertable into the collars  51 ,  52  in such a manner that the safety extension members  31  lie at substantially the same inclined angle as the ladder  20  when the assembly  10  is laid against the intended structure or vehicle, i.e., is placed in the operable position. In essence, both the ladder  20  and the safety extension  30  lie in substantially the same plane when the assembly  10  is placed in the operable position against the intended structure or vehicle. 
     The support legs  32  may each be provided with one or a plurality of apertures, openings or holes  35  which correspond to a hole  55  in the upper collar  51 . These holes  35 ,  55  are sized to receive one or more locking pins  56  configured to selectively retain or otherwise restrict the support legs  32  within the channel  53 . The use of a plurality of holes  35  permits appropriate indexing of the safety extension member  31  to a selected height above the walk-through section  21 . The adjustable nature of the safety extension members  31  makes the assembly  10  accommodating to users of varying heights. Each locking pin  56  may be permanently or removeably affixed to each side rail  23  via a chain or comparable means. 
     Removal of the locking pin  56  from the corresponding holes  35 ,  55  permits selective rotational and/or longitudinal movement of the safety extension members  31  about a vertical axis at the channel  53 . Such movement permits the safety extension members  31  to be moved between operable and inoperable positions and permits selective height adjustments to the safety extension members  31 . For example, in the operable position, the safety extension members  31  are flared outwardly relative to the side rails  23 , thus making the handgrips  33  accessible for grasping by the user. In the inoperable position, the handgrips  33  are flared inwardly so that a first safety extension member  31  contacts, abuts or otherwise engages the other safety extension member  31 . The size of the collars  51 ,  52  are not limited to any one particular size, and thus, may vary depending on the application. 
     As shown in  FIGS. 6A and 6B , a mechanism  60  for stowing away the safety extension members  31  is attached by bolt or comparable means to the front section  25  and rear section  26  of the frame of the ladder  20 . A pair of cylindrical-shaped mounting collars including an upper collar  61  and a lower collar  62  which permit removable coupling of the safety extension members  31  to the ladder  20 . The upper collar  51  is located proximate the walk-through area  21  while the lower collar  52  is spaced therebelow towards the base end  22  of the ladder  20 . The collars  51 ,  52  have an annular channel  53  therein sized to receive the lower leg portion of each safety extension member  31  while the lower collar  52  further includes a stop member  54  at a lowermost portion thereof which abuts, contacts or otherwise engages the bottommost portion of the safety extension member  31  once received therein. The size of the collars  51 ,  52  are not limited to any one particular size, and thus, may vary depending on the application. 
     In order to safely stow the disassembled assembly  10  in a storage area or compartment of a vehicle or structure, a portable rectangular-shaped box, bin or container having an interior spaced sized to receive the assembly  10  may be used. The container may have a hinged or removable opening moveable between an open position allowing the assembly  10  to be fully inserted into the interior space and a closed position sealing the assembly  10  within the space. For those applications requiring use of a transport vehicle such as a truck, trailer and the like, the portable storage container may be fitted and secured underneath the trailer flatbed, permitting easy access thereto when needed. 
     The components for the ladder  20  and the safety extension  30  are preferably constructed of durable and robust materials such as fiberglass, aluminum, composites, or comparable materials known in the art. While components such as the safety extension  30 , stabilizing mechanism(s)  40  and storage assembly  50  are shown herein as a unitary assembly, they are adaptable for retrofitting to existing ladders structures and architectures. 
     It is apparent that innumerable variations of the preferred embodiments described hereinbefore may be utilized. However, all such variations within the spirit and scope of the invention are deemed to be covered by the following claims.