Abstract:
A truck catwalk system for allowing an individual to easily access the interior of a truck box. The inventive device includes a pair of support brackets, at least one pivot bracket, a pair of chains attached to the support brackets, a catch mechanism pivotally attached to one of the support brackets, a platform pivotally attached to the support brackets and catchably engaged by the catch mechanism, a foldable rail structure attached to the platform, a handle attached to the platform, and a ladder attached to the platform and the truck box.

Description:
CROSS-REFERENCE TO RELATED U.S. PATENT APPLICATION 
     I hereby claim benefit under Title 35, United States Code, Section 120 of U.S. patent application Ser. No. 09/631,215 filed Aug. 3, 2000, now U.S. Pat. No. 6,431,093. This application is a continuation-in-part application. The Ser. No. 09/631,215 application is currently pending and will officially issue into a patent on Aug. 13, 2002. The Ser. No. 09/631,215 application is hereby incorporated by reference into this application. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to a catwalk system and more specifically it relates to a truck catwalk system for allowing an individual to easily access the interior of a truck box. 
     2. Description of the Prior Art 
     Devices for accessing the interior portions of a truck box have been in use for years. Typically, individuals operating a truck to access the interior portions of the truck box utilize a conventional ladder permanently attached to the truck box. These conventional ladders are generally comprised of a pair of vertical support members with a plurality of step members secured between the pair of vertical support members. The conventional ladder is further attached to the truck box by a number of support brackets that maintain the conventional ladder in the desired position. Alternatively, an operator of a truck may bring a conventional unattached ladder, which may be loosely retained, upon the truck box or within the truck. 
     The main problem with conventional ladder devices is that they cannot be repositioned about the truck box to allow the individual to access various portions of the truck box. Another problem with conventional ladders is the fact that they are not able to be folded and still maintain the required height and width requirements to travel down the road safely. Conventional ladders that are not secured to the truck box are extremely dangerous to utilize by an individual because of the significant risk of falling. 
     Examples of patented access devices include U.S. Pat. No. 3,601,220 to Saucier; U.S. Pat. No. 2,767,032 to Mitchell; U.S. Pat. No. 5,634,681 to Gionta; U.S. Pat. No. 5,799,962 to Barnhart; U.S. Pat. No. 4,371,056 to Anglade; U.S. Pat. No. 3,989,122 to Jenkins; U.S. Pat. No. 3,493,079 to Dudschus; U.S. Pat. No. 3,110,359 to Solomon, which are all illustrative of such prior art. 
     While these devices may be suitable for the particular purpose to which they address, they are not as suitable for checking the cargo of the box of the truck because the prior catwalks are to low to the ground, and without a safe way of getting from the ground to the catwalk. The previous inventions cannot be folded while maintaining the height and width restrictions for traveling down the road safely. 
     In these respects, the truck catwalk system according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in so doing provides an apparatus primarily developed for the purpose of checking the cargo in the box of a truck system. 
     SUMMARY OF THE INVENTION 
     In view of the foregoing disadvantages inherent in the known types of catwalks now present in the prior art, the present invention provides a new truck catwalk system construction wherein the same can be utilized for checking the cargo in the box of a truck system. 
     The general purpose of the present invention, which will be described subsequently in greater detail, is to provide a new truck catwalk system that has many of the advantages of the ladder devices mentioned heretofore and many novel features that result in a new truck catwalk system which is not anticipated, rendered obvious, suggested, or even implied by any of the prior art ladder devices, either alone or in any combination thereof. 
     To attain this, the present invention generally comprises a pair of support brackets, at least one pivot bracket, a pair of chains attached to the support brackets, a catch mechanism pivotally attached to one of the support brackets, a platform pivotally attached to the support brackets and catchably engaged by the catch mechanism, a handle attached to the platform, a guard rail structure attached to the platform and a ladder attached to the platform and the truck box. The platform is comprised of a flat rectangular surface attached to the truck box by pivotal brackets. The support brackets are attached to the truck box to support the weight of the platform. The chains help to support the outer edge of the platform furthest from the box. The handle is utilized to lower and raise the platform. In an alternative embodiment, a pair of gears are attached to the handle and the platform wherein the gears are mechanically engaged with one another. The user manipulates the handle that rotates a first gear which rotates a second gear and the platform with respect to the truck box. The ladder is pivotally attached to the platform and the truck box. 
     There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the invention that will be described hereinafter and that will form the subject matter of the claims appended hereto. 
     In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of the description and should not be regarded as limiting. 
     A primary object of the present invention is to provide a truck catwalk system that will overcome the shortcomings of the prior art devices. 
     A second object is to provide a truck catwalk system that allows the user to access the top of the box effectively and efficiently. 
     Another object is to provide a truck catwalk system that is comprised of a compact structure. 
     An additional object is to provide a truck catwalk system that allows the user to walk and check an entire side of the truck box at one time. 
     Other objects and advantages of the present invention will become obvious to the reader and it is intended that these objects and advantages are within the scope of the present invention. 
     To the accomplishment of the above and related objects, this invention may be embodied in the form illustrated in the accompanying drawings, attention being called to the fact, however, that the drawings are illustrative only, and that changes may be made in the specific construction illustrated and described within the scope of the appended claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Various other objects, features and attendant advantages of the present invention will become fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein: 
     FIG. 1 is an upper perspective view of the present invention. 
     FIG. 2 is a side view of the present invention showing the catwalk in the storage position. 
     FIG. 3 is a side view of the present invention showing the catwalk in the extended position. 
     FIG. 4 is a rear view of the present invention showing the catwalk in the extended position. 
     FIG. 5 is a rear view of the present invention showing the catwalk being manipulated into the storage position. 
     FIG. 6 is a rear view of the present invention showing the catwalk in the storage position. 
     FIG. 7 is a top view of the present invention showing the catwalk in the storage position. 
     FIG. 8 is a top view of the present invention showing the catwalk in the extended position. 
     FIG. 9 is a side view of an alternative embodiment of the present invention disclosing a first gear and a second gear. 
     FIG. 10 is a side view of the alternative embodiment showing the catwalk in the extended position. 
     FIG. 11 is a rear view of the alternative embodiment showing the catwalk in the extended position. 
     FIG. 12 is a rear view of the alternative embodiment showing the catwalk in the half way folded position. 
     FIG. 13 is a rear view of the alternative embodiment showing the catwalk in the closed or folded position. 
     FIG. 14 is a magnified view of the gear movement system used to lower or raise the platform within the alternative embodiment. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Turning now descriptively to the drawings, in which similar reference characters denote similar elements throughout the several views, FIGS. 1 through 8 illustrate a truck catwalk system  10 , which comprises a pair of support brackets  20 , at least one pivot bracket  22 , a pair of chains  24  attached to the support brackets  20 , a catch mechanism  30  pivotally attached to one of the support brackets  20 , a platform  40  pivotally attached to the support brackets  20  and catchably engaged by the catch mechanism  30 , a guard rail structure extending upwardly from the platform, a handle  50  attached to the platform  40 , and a ladder  60  attached to the platform  40  and the truck box  12 . 
     The platform  40  is comprised of a flat rectangular surface attached to the truck box  12  by pivot brackets as best shown in FIG. 1 of the drawings. A support shaft  44  is attached to the inner portion of the platform  40  for pivotally attaching the platform  40  to the truck box  12 . A mesh  42  preferably extends between the perimeters of the platform  40  to support an individual walking upon the platform  40  though a solid structure may also be utilized. It can be appreciated that the platform  40  may be comprised of various shapes and structures. 
     As best shown in FIGS. 1 and 2 of the drawings, one or more support brackets  20  are attached to the truck box  12  to support the weight of the platform  40 . The support brackets  20  are preferably attached vertically upon the outer side wall of the truck box  12  by a conventional securing means such as but not limited to fasteners or welding. The support brackets  20  may be constructed of any rigid structure such as angle iron. 
     One or more pivot brackets  22  are attached to the support brackets  20  and/or to the truck box  12  for pivotally receiving the support shaft  44  of the platform  40 . The pivot brackets  22  may be constructed of any well-known structure for rotatably retaining a structure. 
     As best shown in FIGS. 1 through 4 of the drawings, one or more chains  24  are attached to the support brackets  20  and to the outer portions of the platform  40  opposite of the support shaft  44  to support the platform  40  in a horizontal position when fully extended. As best shown in FIG. 4 of the drawings, the chains  24  support the outer portion of the platform  40  when fully extended in a horizontal position including the weight of an individual positioned upon the platform  40 . It can be appreciated that rope, cable, cord or other structures may be utilized in place of the chain to support the platform  40  when in the extended position. 
     As shown in FIG. 5 of the drawings, the handle  50  is utilized to lower and raise the platform  40  by an individual physically manipulating the distal portion of the handle  50 . As best shown in FIG. 4 of the drawings, the handle  50  is nonmovably attached to the platform  40  such as to the support shaft  44  or to the end portion of the platform  40 . The handle  50  is an elongated rigid structure that is easy to grasp by an individual. The handle  50  is preferably parallel to the plane of the platform  40  as further shown in FIG. 4 of the drawings. 
     As shown in FIGS. 4 through 6 of the drawings, the catch mechanism  30  is pivotally attached to one of the support brackets  20  for selectively engaging the platform  40  when in the storage position. The catch mechanism  30  is preferably constructed of a hook structure that is pivoted downwardly upon the platform  40  when in a vertical position adjacent the side of the truck box  12 . The catch mechanism  30  may be constructed of various structures designed for engaging the platform  40  when in the storage position. A spring or similar device is utilized between the catch mechanism  30  and the support bracket  20  to apply a downward force upon the catch mechanism  30  to prevent accidental removal of the catch mechanism  30  while retaining the platform  40  in a storage position. 
     As best shown in FIG. 5 of the drawings, the ladder  60  is pivotally attached to the outer portion of the platform  40  and the truck box  12 . The ladder  60  is generally comprised of two vertical orientated braces and a plurality of horizontal braces. One or more support arms  62  are pivotally attached between the ladder  60  and the truck box  12  as shown in FIGS. 4 through 6 of the drawings. The support arms  62  fold with the platform  40  to stay with in a safe width during driving conditions as shown in FIG. 5 of the drawings. 
     As shown in FIG. 1 of the drawings, a first lower member  37  and a second lower member  77  are pivotally attached to outer corners of the platform  40 . The first lower member  37  and the second lower member  77  extend upwardly and substantially transversely from the platform when in the platform  40  is positioned down as shown in FIG. 1 of the drawings. The first lower member  37  and the second lower member  77  extend upwardly and parallel to the platform when in the platform  40  is positioned in a storage position as shown in FIG. 6 of the drawings. 
     As shown in FIG. 1 of the drawings, a first upper member  35  is pivotally attached to the first lower member  37  by a first hinge  36 . As shown in FIG. 1 of the drawings, a second upper member  75  is pivotally attached to the second lower member  77  by a first hinge  76 . A front rail  33  is pivotally attached between the upper ends of the first upper member  35  and the second upper member  75  as further shown in FIG. 1 of the drawings. 
     As shown in FIGS. 1 and 2 of the drawings, a first bracket  38  and a second bracket  78  is attachable to the side of the truck box  12 . A first rail  32  and a second rail  34  are pivotally attached to the first bracket  38  and the second bracket  78  extending outwardly from the truck box  12 . The distal ends of first rail  32  and the second rail  34  are attached to the front rail  33  forming a solid U-shaped structure which the first upper member  35  and the second upper member  75  are pivotally connected to. 
     In an alternative embodiment shown in FIGS. 9 through 14 of the drawings, a first gear  70  is attached to the handle  50 , and a second gear  72  is attached to the platform  40  or support shaft  44  wherein the gears  70 ,  72  are mechanically engaged with one another. The user manipulates the handle  50  which rotates a first gear  70  which rotates a second gear  72  and the platform  40  with respect to the truck box  12 . 
     In use, the platform  40  is lowered by releasing the catch mechanism  30  from the platform  40 . Once the catch mechanism  30  is released from the platform  40 , the user then rotates the handle  50  upwardly causing the platform  40  to extend outwardly from the truck box  12 . As the individual manipulates the handle  50 , the platform  40 , the ladder  60  and guide rail structure start to unfold. As the platform  40  is unfolding, the support arms  62  on the ladder  60  are unfolded to the horizontal position as best shown in FIG. 4 of the drawings. When the platform  40  is in a horizontal position the ladder  60  is in a substantially vertical position and the guide rail structure is fully extended forming a cage structure for when an individual stands upon the platform  40 . The chains  24  are taut carrying a portion of the weight of the platform  40  while the support arms  62  are in the horizontal position as shown in FIG. 4 of the drawings. To close the platform  40  into a storage position, the user rotates the handle  50  downwardly until the platform  40  is in the vertical position as shown in FIG. 6 of the drawings. When the platform  40  is substantially vertically orientated, the user manipulates the catch mechanism  30  upon the platform  40  to prevent the platform  40  from accidentally extending horizontally. With this the chains  24  are loose, the ladder  60  and the support arms  62  are in the vertical position substantially parallel to the ladder  60 . 
     With the alternative embodiment shown in FIGS. 9 through 14, the movements of the components are substantially the same. To extend the platform  40  into a horizontal position, the handle  50  is rotated upwardly causing the first gear  70  to rotate the second gear  72  in an opposite rotational direction. As shown in FIG. 12 of the drawings, when the individual desires to fold the platform  40  upon the truck box  12  into the storage position the handle  50  is manipulated in a direction opposite of that utilized to extend the platform. Once the platform  40  is in the vertical storage position, the catch mechanism  30  is positioned about the platform  40  to retain the platform  40  in the desired position. 
     As to a further discussion of the manner of usage and operation of the present invention, the same should be apparent from the above description. Accordingly, no further discussion relating to the manner of usage and operation will be provided. 
     With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed to be within the expertise of those skilled in the art, and all equivalent structural variations and relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention. 
     Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.