CATWALK ASSEMBLY

Abstract

A walkway is provided for use with an accessed container. The walkway comprises a fixed platform and a support structure connected to the fixed platform so as to allow the support structure to pivot relative to the fixed platform between a raised, stowed position and a lowered, deployed position. An end platform is pivotally connected to the distal end of the support structure. The end platform defines an upper walking surface and a lower surface that engages with the top of the container. The height between the lower surface and the walking surface is no greater than 2.54 cm (1 inch).

Description

CATWALK ASSEMBLY Field of Invention The present invention relates to fall restraint equipment, and more particularly, to a walkway that is operative to move between a raised (stowed) position and a lowered (deployed) position. Background of the Invention Gangways can be used to provide access from a platform to an area such as the top of a storage container, a vehicle, or a ship. For example, a semi-trailer truck or a railroad car carrying dry goods may need to be inspected, loaded, or unloaded from the top of the container. A gangway is used to span the distance between a stationary platform and the top of the container. In this regard, the proximal end of the gangway is pivotally connected to the stationary platform for storage in an elevated position. A foot lock is usually provided to hold the gangway in the elevated position. Once the container is in position, the operator releases the foot lock, allowing the gangway to move to its lowest position. Once fully lowered, a platform at the distal end pr / οηη / ζζηζ / Ε / γίΛA Ref. 336066 of the walkway will be next to the top of the container. When access to the top of the container is no longer required (for example, due to the completion of the unloading process), the gangway is manually raised to the stowed position until the foot lock is engaged. In a common arrangement, heavy-duty chains are attached to each side of the gangway near its distal end. The chains can be locked to the platform uprights to prevent the gangway from lowering further when the desired location is reached. The chains are then pulled to raise the gangway to its raised position. Brief Description of the Invention The present invention recognizes and addresses the above and other considerations of prior art construction and methods. An aspect of the present invention provides a walkway for use with a container to be accessed. The walkway comprises a fixed platform and a support structure connected to the fixed platform such that the support structure is able to rotate relative to the fixed platform between a raised, stowed position and a lowered, deployed position. An end platform is pivotally connected at the distal end of the support structure, the end platform defining an upper walking surface and a lower surface that engages the top of the container, the height between the lower surface and the walking surface being no greater than 2.54 cm (1 inch). In some exemplary embodiments, the end platform comprises a main platform structure formed by a lower member and a separate upper member assembled together. For example, each of the lower member and the upper member may be formed from a single piece of sheet metal. The upper member may define a pair of opposing side flanges on respective lateral sides of the walking surface. In addition, the first and second side structures may be attached to respective outer surfaces of the side flanges. Each of the side structures may comprise first and second uprights. The upper member may further comprise an end channel in which a front edge of the lower member sits. In some exemplary embodiments, the lower member may include a pair of opposing side plates defining side plate holes aligned for the passage of a shaft. The side structures in such embodiments may define respective dependent flanges defining flange holes aligned with the side plate holes. A portion of the support structure may interpose each of the side plates and a respective one of the dependent flanges of the respective side structures. Embodiments are contemplated in which the end platform comprises a main platform structure formed from a unitary piece of sheet metal configured to provide the walking surface, the bottom surface, opposing side flanges, and opposing side members. According to some embodiments, a distal end of the end platform defines a channel in which a resilient bumper is seated. The walkway may also include a self-rising assembly operative to rotate the support structure from the deployed position to the stowed position. Other aspects of the present invention provide a walkway for use with a container to be accessed. The walkway comprises a fixed platform and a support structure connected to the fixed platform such that the support structure can rotate relative to the fixed platform between a raised, stowed position and a lowered, deployed position. An end platform is pivotally connected at the distal end of the support structure. The end platform defines an upper walking surface and a lower surface that engages the top of the container. The end platform has a main platform structure formed by a lower member and a separate upper member assembled together. Yet another aspect of the present invention provides a walkway for use with a container to be accessed. The walkway comprises a fixed platform and a support structure connected to the fixed platform such that the support structure can rotate relative to the fixed platform between a raised, stowed position and a lowered, deployed position. First and second proximal uprights are located on lateral sides of the support structure. First and second distal uprights are also located on lateral sides of the support structure. A first handrail is pivotally connected to the first proximal upright and the first distal upright. A second handrail is pivotally connected to the second proximal upright and the second distal upright.Each of the first and second handrails has a portion of main tube from which unitary tabs extend, where the uprights are connected at the tabs. In some exemplary embodiments, the main tube portion and the fins comprise a section of a continuous aluminum extrusion. Furthermore, each of the first and second handrails may comprise an independent handhold attached to the main tube portion. Furthermore, each of the first and second handrails may comprise a pair of end caps connected to respective ends of the main tube portion. In some exemplary embodiments, the walkway may further comprise a first center rail pivotally connected to the first proximal upright and the first distal upright, and a second center rail pivotally connected to the second proximal upright and the second distal upright. At least one of the center rails in those embodiments may comprise an end cap having a manufacturer's indicia thereon. The attached figures, which are incorporated into and constitute part of this description, illustrate one or more embodiments of the present invention. Brief Description of the Figures In the description, which refers to the attached figures, in which: Figure 1 illustrates a prior art walkway assembly lowered so that its distal end is adjacent to a container, with a portion enlarged so that additional details can be more easily seen. Figure 2 is a view similar to Figure 1 of a walkway assembly constructed in accordance with an embodiment of the present invention. Figure 3 is a perspective view of a walkway assembly constructed in accordance with an embodiment of the present invention. Figure 4 is a perspective view of the end platform of the walkway assembly of Figure 3. Figure 5 is a side elevation of the end platform of the walkway assembly of Figure 3. Figure 6 is a cross-sectional view of the end platform taken along line 6-6 of Figure 4. Figures 7 and 8 are perspective views of separate unitary pieces of the end platform in accordance with an embodiment of the present invention. Figure 9 is a perspective view of the separate unit pieces of Figures 7 and 8 assembled together. Figures 10-12 are enlarged perspective views showing certain details of the attachment of the end platform to the support structure of the walkway assembly of Figure 3. Figures 13-17 are perspective views showing the folding sequence of a unitary panel to / οηη / ζζηζ / Ε / γίΛA form a portion of an end platform according to an embodiment of the present invention. Figure 18 is a cross-sectional view showing the portion of the end platform formed in Figures 13-17 assembled with other components. Figure 19 is a cross-sectional view showing the configuration of another embodiment of an end platform according to the present invention. Figure 20 is a perspective view of a handrail that can be used with a walkway assembly in accordance with an embodiment of the present invention. Figure 21 is a perspective view of the main body of the handrail of Figure 20. Figure 22 is a perspective view of an end cap of the handrail of Figure 20. Figure 23 is a perspective view of the grip body of the handrail of Figure 20. Figure 24 is a perspective view of an intermediate rail that can be used with a walkway assembly in accordance with an embodiment of the present invention. Figure 25 is a perspective view of an end cap of the intermediate rail of Figure 24. The repeated use of reference characters in the present description and figures is intended to represent the same or analogous features or elements of the invention. Detailed Description of the Invention Reference will now be made in detail to the presently preferred embodiments of the invention, one or more examples of which are illustrated in the accompanying figures. Each example is provided by way of explanation of the invention, not as a limitation of the invention. Indeed, it will be apparent to those skilled in the art that modifications and variations may be made in the present invention without departing from the scope or spirit thereof. For example, features illustrated or described as part of one embodiment may be used in another embodiment to produce yet another embodiment. Therefore, it is intended that the present invention cover modifications and variations that fall within the scope of the appended claims and their equivalents. Examples of gangways, their components, and associated fall restraint equipment are set forth in U.S. Patent No. 7,950,095 (entitled Gangway and Method for Manufacturing Same), 8,387,191 (entitled Gangway Bearing Retainer Plate), U.S. Patent No. 10,145,070 (entitled Gangway Having Hydraulic Position Locking Assembly), and U.S. Patent No. 10,253,464 (entitled Gangway Having Position Locking Assembly), all of which are incorporated in their entirety herein by reference for all purposes. Furthermore, it is anticipated that aspects of a gangway as described herein may be used in connection with a self-raising gangway as described in U.S. Publication No. 2020 / 0317456, published on October 8, 2020, and entitled Gangway Having Self-Raising Assembly, which is also incorporated in its entirety herein by reference for all purposes. Figure 1 illustrates a prior art walkway 10. The proximal end of the walkway 10 is pivotally connected to a fixed platform 12 positioned at the appropriate height above the ground surface. In this case, for example, the walkway 10 is positioned so that it can be moved from a raised (stowed) position to a lowered (deployed) position relative to a container (such as a trailer 14) to be loaded or unloaded. As one skilled in the art will understand, such containers often have one or more hatches in the top that need to be accessed by a worker. For example, the platform 12 may be held at this height by a support column (not shown). The walkway 10 has a support structure 16 that pivots relative to the platform 12. (As used herein, the term platform as it relates to platforms 12 and 112 may refer to the entire platform 12 / οηη / ζζηζ / Ε / γίΛA or to a portion of the walkway 10 that is attached.) Furthermore, the terms proximal end and distal end of the support structure and / or walkway refer to the area near the actual nearer and farther ends of the platform 12 or 112.) A ramp (or pivoting stair assembly) is carried by the support structure. The walkway 10 further includes a pair of parallel handrails (e.g., handrail 18) between which the operator walks to access the top of the container. Intermediate handrails, such as intermediate handrail 20, may also be provided. The respective ends of the handrails and intermediate rails are pivotally connected to the proximal and distal uprights 22 and 24. An end platform 26 (sometimes called a seat post) is located at the distal end of the support structure 16. As shown, the end platform 26 may carry end uprights, such as upright 28, located on the left and right sides of the platform 26. The end uprights may be attached to the distal uprights 24 via cross members, such as cross member 30. As can be seen more easily in the enlarged part of Figure 1, the end platform 2 6 has a height (i.e. a vertical thickness) typically in the range of several centimeters (ten centimeters or more). / oza / zza / E / gala As a result, the walking surface of the end platform will be raised above the top of the container by an equivalent amount when the end platform 26 rests on top of the container. This may require the worker to step down from the end platform to the top of the container. Depending on the shape or configuration of the top of the container, such a step may be considered undesirable. Additional aspects of a prior art walkway are shown in U.S. Patent No. 7,950,095. 2 and 3 , a walkway 100 constructed in accordance with one embodiment of the present invention is illustrated. The walkway 100 has a support structure 116 pivoted relative to the platform 112. The walkway 100 further includes a pair of parallel handrails 118 between which the operator walks to access the top of the container. Midrails 120 may also be provided. Respective ends of the handrails and midrails are pivotally connected to proximal and distal uprights 122 and 124. An end platform 126 is located at the distal end of the support structure 116. As shown, the end platform 126 may have end uprights, such as upright 128, located on the left and right sides of the platform 126. The / οηη / ζζηζ / Ε / γίΛΐ end uprights may be attached to the distal uprights 124 via crosspieces 130. Referring now specifically to Figure 3, the support structure 116 in this case supports a pivoting stair assembly 132. (In other embodiments, the support structure 116 may include a ramp instead of pivoting stairs.) In this view, the walkway 100 is oriented in the down (deployed) position. As will be appreciated by one of skill in the art, the walkway 100 may be stored when not in use by rotating the support structure 116 so that it is oriented in an up (i.e., generally vertical) position. As is known in the prior art, manual raising and lowering of the walkway 100 may be facilitated by counterbalance springs located on the lateral sides of the support structure 116. In this embodiment, however, a pair of hydraulic cylinders 134 are provided at the locations where the counterbalance springs would otherwise be. (It should be noted that the actual cylinders may be contained within a sleeve, as shown.) The hydraulic cylinders are part of an automatic lifting assembly (or more simply, lift assembly) that moves the support structure 116 to the stowed position when actuated by a user. Such a self-elevating assembly is described in more detail in the aforementioned U.S. publication No. 2020 / 0317456. As indicated at 136 and 138, each cylinder may be connected in this embodiment between a fixed structure on the platform 112 and the distal end area of ​​the support structure 116. For example, the proximal end of the cylinder 134 is in this case attached to a bracket 140 which in turn is attached to the outer side of the upright 122. A pair of side chains 142 are provided to lock the walkway in the lowered position (i.e., to prevent it from lowering further). A pull rope 144 is provided for actuating an automatic lifting assembly. Referring again to Figure 2, it can be seen that the end platform 126 has a novel configuration. In particular, the height of the end platform 126 between the bottom surface that engages the top of the container 14 and the walking surface 142 is minimized (e.g., preferably no more than about 2.54 cm (1 inch)). As a result, a worker accessing the top of the container 20 is not required to step from the end platform 126 to the top of the container as was the case with the prior art walkway shown in Figure 1. / oza / zza / E / gala Referring now to Figures 4-6, certain additional details of the end platform 126 can be seen. As shown, the uprights 124 and 128 and the cross member 130 are integral parts of the first and second side structures 144 and 146 that are attached to the lateral sides of a main platform structure 148, for example by welding. The main platform structure 148 defines the walking surface 142 as well as the bottom surface 150 that rests on the container 14. As shown in Figures 7-9, the main deck structure 148 is formed in this embodiment by two pieces that are assembled together. In this regard, the lower piece 152 (Figure 7) is placed beneath the upper piece 154 (Figure 8) until its leading edge 156 seats properly in a channel 158 defined by the upper piece 154. The pieces 152 and 154 are then secured relative to each other, such as by welding. As can be seen, the lower piece 152 defines integral side plates 160, a back plate 162 (Figure 9), and transverse ribs 164, all formed in this embodiment by bending a flat piece of sheet metal. As shown, the side plates 160 define aligned holes 161. Similarly, the top piece 154 has side flanges 166, also formed in this embodiment by bending a flat piece of sheet metal.In addition, the walking surface 142 is textured by drilling a series of perforations through the top piece 154. Certain additional details are shown in Figures 10-12. In this regard, it can be seen in Figure 10 that the cylinder 134 is attached to the support structure 116 near the end platform 126 through a respective flange 168 (thus forming the distal attachment location 138). A distal end of the chain 142 can also be attached to the flange 168, as well as a guide for the pull rope 144. Each of the side structures 144 and 146 carries a pair of hanger flanges 170 between which is received an end portion of the support structure 116. In this regard, the flanges 170 define holes (e.g., hole 172) that align with a hole in the end portion of the support structure 116 and holes 161. A rod (shaft) 174 extends through all of these aligned holes to allow relative rotation between the support structure 116 and the end platform 126 as the walkway 100 is raised and lowered. Bushings, such as bushing 176, may be located in the aligned holes to facilitate the rotation. Retaining collars, such as collar 178, may be provided around the rod 174 near its two ends to hold the rod in position. A tube 180 may be fixed between the side plates 160 to enclose the rod 174 in this region and strengthen the overall assembly. Figures 13-17 illustrate the formation of an end platform in which a large portion of the end platform is formed using a single piece of sheet metal. Like the previous embodiment, this embodiment provides a minimum height between the bottom surface that engages the container and the walking surface. In this regard, Figure 13 shows a cut blank 182 of sheet metal that will be used to form the end platform. Next, as shown in Figure 14, a first end portion 184 is folded to be perpendicular to the remainder of the blank 182. A plurality of transverse ribs 186 are also formed. As shown in Figure 15, the side plates 188 are folded to be perpendicular to the remainder of the end portion 184. A second end portion 190 is folded to be oriented partly perpendicular and partly oblique to the remainder of the blank 182. Next, as shown in Figure 16, portion 192, carrying the end portion 184 and the side plates 188, is folded downward. This forms the bottom surface of the end platform. Referring now to Figure 17, the side flanges 194 are folded to be perpendicular to the portion 196 of the blank 182 that forms the walking surface. The joining locations where the material is joined can be suitably secured, for example, by welding. As shown in Figure 18, a tube 198 can be added to contain the axle rod. Additional supports, such as the cross beam 200, can also be provided. One skilled in the art will appreciate that the tube 188 and beam 200 will be suitably secured to the blank 182, for example, by welding. Figure 19 illustrates yet another embodiment of an end platform 210 that also has a minimum height between the container-engaging bottom surface 212 and the walking surface 214. In this embodiment, the distal end defines a channel wherein a resilient bumper 216 is received. Referring now to Figures 20-23, certain additional details about a preferred embodiment of a handrail 118 can be more easily explained. As shown, the handrail 118 has a main tube portion 300 to which a handhold 302 is attached (e.g., using screws or rivets). End caps 304 are located at each end of the main tube portion 300. In addition, integral tabs 306 depend from the main tube portion 300 to facilitate attaching the handrail 118 to the walkway uprights. Preferably, the main tube portion 300 may be formed from a pr / οηη / ζζηζ / Ε / γίΛA extrusion (e.g., an aluminum extrusion) having a cylindrical portion and a longitudinal fin. After cutting the extrusion to length, the fin can be machined to form the 306 tabs.In other words, the tabs are formed as a unit with the main tube portion, rather than as separate pieces that are joined later. In particular, the handle 302 may bear a logo 308 identifying the manufacturer of the walkway. Certain additional details of the intermediate rail 120 can be more easily explained with reference to Figures 24-25. As can be seen, the intermediate handrail 120 has a main tube portion 310 defining holes 312 to facilitate attachment to the walkway uprights. End caps 314 are located at each end of the main tube portion 310. Preferably, the main tube portion 310 may be formed from an extrusion (e.g., an aluminum extrusion) that is cut to size. For example, in this embodiment, the main tube portion 310 is formed as a hexagonal tube. The end caps 314 may carry a logo 316 identifying the manufacturer of the walkway. Those skilled in the art will appreciate that the foregoing description provides a novel walkway arrangement. While one or more preferred embodiments of the invention have been described above, it is to be understood that any and all equivalent embodiments of the present invention are included within the scope and spirit thereof. The depicted embodiments are presented by way of example only and are not intended to limit the present invention. Furthermore, it should be understood by those skilled in the art that the present invention is not limited to these embodiments, as modifications may be made. Therefore, it is contemplated that any and all embodiments are included in the present invention that may fall within the scope and spirit thereof. It is noted that in relation to this date, the best method known to the applicant to put the aforementioned invention into practice is the one that is clear from the present description of the invention.

Claims

1. A walkway for use with a container being accessed, comprising: a fixed platform; a support structure connected to the fixed platform such that the support structure is able to rotate relative to the fixed platform between a raised, stowed position and a lowered, deployed position; and an end platform pivotally connected at the distal end of the support structure, the end platform defining an upper walking surface and a lower surface engaging the top of the container, the height between the lower surface and the walking surface being no greater than 2.54 cm (1 inch).

2. The walkway according to claim 1, characterized in that the end platform comprises a main platform structure formed by a lower part and a separate upper part assembled together.

3. The walkway according to claim 2, characterized in that each of the lower and upper parts is formed by a single piece of rolled metal.

4. The walkway according to claim 3, characterized in that the upper piece defines a pair of opposite side flanges on respective lateral sides of the walking surface.

5. The walkway according to claim 4, characterized in that the end platform further comprises first and second side structures attached to respective outer surfaces of the side flanges.

6. The walkway according to claim 5, characterized in that each of the side structures comprises first and second uprights.

7. The walkway according to claim 4, characterized in that the upper piece further comprises an end channel in which a front edge of the lower piece sits.

8. The walkway according to claim 5, characterized in that the lower part includes a pair of opposite side plates defining side plate holes aligned for the passage of an axis.

9. The walkway according to claim 8, characterized in that the side structures define respective dependent flanges defining flange holes aligned with the side plate holes.

10. The walkway according to claim 9, characterized in that a portion of the support structure interposes each of the side plates and a respective one of the flanges dependent on the respective side structures.

11. The walkway according to claim 1, characterized in that the end platform comprises a main platform structure formed by a unitary piece of rolled metal configured to provide the walking surface, the bottom surface, opposite side flanges and opposite side pieces.

12. The walkway according to claim 1, characterized in that a distal end of the end platform defines a channel in which a resilient bumper is seated.

13. The walkway according to claim 1, characterized in that it further comprises a self-elevating assembly operative to rotate the support structure from the deployed position to the stowed position.

14. A walkway for use with an accessed container, comprising: a fixed platform; a support structure connected to the fixed platform such that the support structure is able to rotate relative to the fixed platform between a raised, stowed position and a lowered, deployed position; and an end platform pivotally connected at the distal end of the support structure, the end platform defining an upper walking surface and a lower surface engaging the top of the container, the end platform having a main platform structure formed by a lower member and a separate upper member assembled together.

15. The walkway according to claim 14, characterized in that each of the lower and upper pieces are formed by a single piece of rolled metal.

16. The walkway according to claim 15, characterized in that the upper piece defines a pair of opposite side flanges on respective lateral sides of the walking surface.

17. The walkway according to claim 16, characterized in that the end platform further comprises first and second side structures attached to respective outer surfaces of the side flanges, wherein each of the side structures has first and second uprights.

18. The walkway according to claim 15, characterized in that the upper piece pr / οηη / ζζηζ / Ε / γίΛA 25 further comprises an end channel in which a front edge of the lower piece sits.

19. The walkway according to claim 16, characterized in that the lower part includes a pair of opposite side plates defining side plate holes aligned for the passage of an axis.

20. The walkway according to claim 14, characterized in that it further comprises a self-elevating assembly operative to rotate the support structure from the deployed position to the stowed position.

21. A walkway for use with an accessed container, comprising: a fixed platform; a support structure connected to the fixed platform such that the support structure is able to rotate relative to the fixed platform between a raised, stowed position and a lowered, deployed position; and first and second proximal uprights located on lateral sides of the support structure; first and second distal uprights located on lateral sides of the support structure; a first handrail pivotally connected to the first proximal upright and the first distal upright; a second handrail pivotally connected to the second proximal upright and the second distal upright; and each of the first and second handrails has a main tube portion from which unitary tabs extend, the uprights being connected at the tabs.

22. The walkway according to claim 21, characterized in that the main tube portion and fins comprise a section of a continuous aluminum extrusion.

23. The walkway according to claim 21, characterized in that each of the first and second handrails comprises a separate handle attached to the main tube portion.

24. The walkway according to claim 23, characterized in that each of the first and second handrails comprises a pair of end caps connected to the respective ends of the main tube portion.

25. The walkway of claim 21, further comprising: a first intermediate rail pivotally connected to the first proximal upright and the first distal upright; and a second center rail pivotally connected to the second proximal upright and the second distal upright.

26. The walkway according to claim 25, characterized in that at least one of the intermediate rails comprises an end cap having markings of a manufacturer thereon.

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