US20140191537A1

US20140191537A1 - Platform grating

Info

Publication number: US20140191537A1
Application number: US13/736,144
Authority: US
Inventors: Matthew A. Bilbruck; Aaron L. Carbonneau; Kyle D. Knous
Original assignee: Caterpillar Inc
Current assignee: Caterpillar Inc
Priority date: 2013-01-08
Filing date: 2013-01-08
Publication date: 2014-07-10
Also published as: CN103912786A

Abstract

A platform grating is provided. The platform grating includes an array of plates placed in a spaced apart arrangement. Each of the array of plates includes a plurality of apertures which are provided in transverse alignment with the apertures in the adjacent plate. The platform grating also includes an array of hollow tubes positioned within the apertures provided in the array of plates. Each of the array of hollow tubes is mechanically connected to the array of plates.

Description

TECHNICAL FIELD

The present disclosure relates to a grating, more particularly to a platform grating for large machines.

BACKGROUND

Platform gratings are used as floor members for machine platforms provided on large machines. These platforms provide ingress and egress to various parts of the machine for operational and/or maintenance purposes. Besides large machines, such platforms are also widely used in industrial premises and on process equipment.
Currently known methods of manufacturing of the platform gratings includes arranging a plurality of plates or bearing bars parallel to each other in a spaced apart arrangement. The plates are securely held in position by a plurality of hollow tubes or rods which are placed perpendicular to the plates and parallel to one another. The hollow tubes are fastened or attached to the plates by welding, bolting, riveting, or any combination thereof. However, individually welding each of the joints of the hollow tube and the plate proves to be time consuming and expensive activity.
Hence, there is a need to provide an improved manufacturing method for the platform gratings which overcomes the above mentioned shortcomings.

SUMMARY OF THE DISCLOSURE

In one aspect of the present disclosure, a platform grating is provided. The platform grating includes an array of plates placed in a spaced apart arrangement. Each of the array of plates includes a plurality of apertures which are provided in transverse alignment with the apertures in the adjacent plate. The platform grating also includes an array of hollow tubes positioned within the apertures provided in the array of plates. Each of the array of hollow tubes is mechanically connected to the array of plates.
In another aspect of the present disclosure, a method of manufacturing a platform grating is provided. The method provides a plurality of apertures in each of an array of plates. The method arranges each of the array of plates in a spaced apart arrangement in such a manner that the apertures of one plate are provided in transverse alignment with the apertures in the adjacent plate. Further, the method positions an array of hollow tubes through the provided apertures. An outer diameter of the hollow tube is less than a diameter of the aperture. Thereafter, the method expands the diameter of the each of the array of hollow tubes to mechanically secure the hollow tube with the plate.
Other features and aspects of this disclosure will be apparent from the following description and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exemplary machine, according to one embodiment of the present disclosure;

FIG. 2 is a perspective view of an operator cabin of the machine shown in FIG. 1;

FIG. 3 is a front view of a plate;

FIG. 4 is a side view a hollow tube;

FIG. 5 is a perspective view of a mandrel;

FIG. 6 is a perspective view of an assembly of the plate and the hollow tube with the mandrel directed through the hollow tube;

FIGS. 7(A) and 7(B) are sectional views showing a profile of the hollow tube before and after directing the mandrel through the tube respectively;

FIG. 8 is a finished platform grating; and

FIG. 9 is a flowchart of a method for manufacturing of the platform grating.

DETAILED DESCRIPTION

Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. FIG. 1 shows an exemplary machine 100, according to one embodiment of the present disclosure. More specifically, the machine 100 is shown as a track type tractor. It should be understood that the machine 100 may alternatively include other machines such as, a track loader, a wheel loader, a compactor, an excavator, a large mining truck, or any other agricultural, mining or construction machinery employing a platform grating.
Referring to FIG. 1, the machine 100 includes a chassis or a frame 102. An engine enclosure 104 houses a power source (not shown) to provide power to the machine 100. The power source may include one or more engines, power plants or other power delivery systems like batteries, hybrid engines, and the like. A set of ground engaging members 106 such as wheels, tracks, rollers, and the like are also provided on the machine 100 for the purpose of mobility. Further, the machine 100 includes an operator cabin 108 which houses controls for operating the machine 100.
FIG. 2 is a perspective view of the operator cabin 108 of the machine 100. As shown in FIG. 2, the operator cabin 108 is provided with a platform 202. The platform 202 facilitates ingress and egress to the operator cabin 108 and other sections of the machine 100 for operational or maintenance purposes. The platform 202 includes at least one platform grating 204 which is used as a floor member of the platform 202. In the illustrated embodiment, the platform grating 204 is bounded by a railing 206 on all sides. The railing 206 may provide safety to an operator from falling off the machine 100.
More specifically, the platform grating 204 may include a mesh type configuration including an array of plates 208 and an array of hollow tubes 210 placed in a spaced apart arrangement. The present disclosure relates to the platform grating 204 in which each of the hollow tubes 210 is mechanically connected to the plates 208. FIGS. 3 and 4 are exploded views of a single plate 208 and a single hollow tube 210 respectively.
Referring to FIG. 3, the plate 208 may include a plurality of apertures 302 provided t through the plate 208 and positioned in an equally spaced manner. Each of the apertures 302 may have a pre-determined diameter which is fixed. The plate 208 is preferably made of metal, such as steel or aluminum, but other materials such as polymers and composites may be equally suitable. Further, the plate 208 has a defined width “W”, height “H” and thickness as indicated in the accompanying figures. It may be noted that these dimensions of the plate 208 may vary as per system design and requirement.
In one exemplary case, the plate 208 may have the width “W” of approximately 1500 mm, the height “H” of approximately 40 mm, and the thickness of approximately 4 mm. Also, the aperture 302 provided on the plate 208 may have the diameter of approximately 13 mm. The spacing provided between any two adjacent apertures 302 may be approximately 30 mm in one exemplary case.
Additionally, as shown in FIG. 3, a top surface 304 of the plate 208 may have a series of crenels 306 provided on it in order to make the floor of the platform 202 rough. The roughness of the platform 202 may reduce accidental slippage by increasing friction provided. As shown, a bottom surface 308 of the plate 208 may have a flat or relatively smooth configuration. It should be noted that an array of such plates 208 may be arranged in a parallel manner with respective to each other to form the platform grating 204. The arrangement of the plates 208 is such that the aperture 302 provided on one of the plates 208 is transversely aligned with the aperture 302 provided on the adjacent plate 208.
Moreover, the hollow tube 210 is configured to be positioned within the aperture 302 provided on the plate 208. An exploded view of the hollow tube 210 is shown in FIG. 4. The hollow tube 210 is generally made of a metal, such as steel. The hollow tube 210 has a length “L”, an initial outer diameter “OD1”, an initial inner diameter “ID1”, and an initial wall thickness “T1”. These dimensional parameters may vary based on the application. In one example, the hollow tube 210 may have an outer diameter “OD1” of approximately 12.7 mm and a wall thickness “T1” of approximately 1.25 mm. It should be noted that the outer diameter “OD1” of the hollow tube 210 is initially less than the diameter of the aperture 302.
In the present disclosure, the hollow tube 210 is mechanically connected to the plate 208 by expanding the inner diameter “ID1” of the hollow tube 210. It should be noted that expansion of the inner diameter “ID1” causes an outer surface of the hollow tube 210 to cooperate with an inner surface of the aperture 302. More specifically, the hollow tube 210 forms an interference fit within the one or more apertures 302. In order to expand the hollow tube 210, a mandrel 500 (shown in FIG. 5) is directed through the full length “L” of the hollow tube 210.
As shown in FIG. 5, the mandrel 500 is a solid cylindrical body having a first end 502 and a second end 504. The first end 502 of the mandrel 500 may have a diameter smaller than a diameter of the second end 504. It should be noted that the design of the mandrel 500 may be such that the first end 502 easily enters into the hollow tube 210, while the second end 504 may cause the expansion of the hollow tube 210.
In one embodiment, a taper 506 may be provided on a surface of the mandrel 500 such that there is a change in the diameter of the mandrel 500 on either side of the taper 506. Alternatively, the mandrel 500 may have a conical shaped configuration to provide a continuous graduation in the diameter between the first and second ends 502, 504 of the mandrel 500. In another embodiment, the first and second ends 502, 504 may have the same diameter. The mandrel 500 may be made of metal, such as, flame hardened mild steel.
It should be noted that dimensions and material used for the mandrel 500 may vary depending upon the manufacturing process needs and system requirements. In one example, the diameter of the second end 504 may be approximately 10.55 mm. Moreover, the mandrel 500 may have an axial hole 508 drilled through it. In one embodiment, a steel cable (not shown) may be passed through the hole 508 of the mandrel 500 to enable pulling of the mandrel 500 along an inner surface of the hollow tube 210.
FIG. 6 depicts a setup 600 of the mandrel 500 inserted within the hollow tube 210 to effectuate the expansion of the hollow tube 210 which is placed within the aperture 302 of the plate 208. In the accompanying figure, the first end 502 of the mandrel 500 is inserted into the hollow tube 210.
Once fitted within the hollow tube 210, the mandrel 500 may be pulled or pushed through the full length “L” of the hollow tube 302 in a variety of ways. In one embodiment, the cable is attached to the second end 504 of the mandrel via the hole 508 present in the mandrel 500. The cable may be attached to the mandrel 500 by a hook, clasp, knot, or any other known method. The cable is made to pass through the hollow tube 210. The mandrel 500 and the attached cable may then be pulled through the full length “L” of the hollow tube 210. Alternatively, in another embodiment, the mandrel 500 may be pushed through the full length “L” of the hollow tube 210 using a hydraulic press, a pneumatic press, or any other similar method known in the art.
FIGS. 7(A) and 7(B) are sectional views showing a profile of the hollow tube 210 before and after directing the mandrel 500 through the hollow tube 210 respectively. As shown, a mechanically secured joint 700 may be formed between the hollow tube 210 and the plate 208 after the mandrel 500 is directed through the hollow tube 210. The initial inner diameter “ID1” of the hollow tube 210 is expanded to a new inner diameter “ID2”. The expansion of the inner diameter “ID1” of the hollow tube 210 causes an outer surface 702 of the hollow tube 210 to form an interference fit with an inner surface 704 of the aperture 302. As shown in FIG. 7(B), after expansion the hollow tube 210 includes a pair of shoulders 706, 708 in cooperation with a first side surface 710 and a second side surface 712 of the plate 208 which is adjacent to the aperture 302.
Due to the expansion of the hollow tube 210, there may be an increase in the initial inner diameter “ID1” of the hollow tube 210 by approximately 3 to 7%. One of ordinary skill in the art will appreciate that the increase in the inner diameter “ID1” of the hollow tube 210 causes a corresponding increase in the outer diameter “OD1” of the hollow tube 210, shown as an outer diameter “OD2” in FIG. 7(B). However, since the hollow tube 210 is positioned within the aperture 302 the expansion of the outer diameter “OD1” may be restricted to that of the diameter of the aperture 302, thereby causing a reduction in the wall thickness “T1” of the hollow tube 210. This new and reduced wall thickness of the hollow tube 210 is shown as “T2” in FIG. 7(B).
In one embodiment, the outer diameter “OD1” of the hollow tube 210 may expand by approximately 2 to 5%. Correspondingly, the wall thickness “T1” of the hollow tube 210 may decrease by approximately 1 to 5%. Accordingly, a shoulder height “SH” (see FIG. 7(B)) may be approximately 0.5 to 1.5% of the wall thickness “T1”. One of ordinary skill in the art will appreciate that when the mandrel 500 is directed through the hollow tube 210, the diameter of the aperture 302 of the plate 208 may change in size and shape. The change in size and shape of the aperture 302 can be considered to be very minimal.
The interference fit shown in FIG. 7(B) may securely hold the hollow tube 210 in place within the aperture 302 of the plate 208. FIG. 8 illustrates top view of a finished platform grating 204, wherein the hollow tubes 210 are securely held within the apertures 302 of the plates 208 by the interference fit formed at the joints 700. It should be noted that the spacing between the plates 208, the spacing between the hollow tubes 210, and overall length of the platform grating 204 may vary as per the application.
An exemplary method 900 for the manufacture of the platform grating 204 will be described in connection with FIG. 9.

INDUSTRIAL APPLICABILITY

Platforms making use of a grating as a floor member are generally provided on large machines for ingress and access to the operator cabin and other sections of the machine. Known platform gratings make use of methods like welding, bolting, riveting, and the like at an intersection of the hollow tube and the plate, in order to hold the grating structure in place. Since the platform grating has a number of such intersections, individually joining each intersection is a laborious and expensive activity. The present disclosure provides a cost efficient and simpler approach for the manufacture of the platform grating 204, further reducing assembly time involved therein.
At step 902, the apertures 302 are provided in each of the plates 208 in an equally spaced arrangement. The spacing between each of the apertures 302 may be based on the application. Further, parameters like size of the apertures 302, number of the apertures 302, and the like may vary. At step 904, the plates 208 are arranged parallel to each other in a spaced apart arrangement within the apertures 302 of one plate 208 which are transversely arranged with respect to the apertures 302 of the adjacent plates 208.
Thereafter, at step 906, the array of hollow tubes 210 are positioned within the apertures 302 in such a manner that each of the hollow tubes 210 is spaced apart from each other in a parallel arrangement. The mandrel 500 is then directed through the full length “L” of the hollow tube 210. In one embodiment, the cable is attached to any one end of the mandrel 500. The mandrel 500 and the attached cable are then pulled through the full length “L” of the hollow tube 210. In another embodiment, the mandrel 500 may be pushed through the full length “L” of the hollow tube 210 using the hydraulic press, pneumatic press, or any other method known in the art.
At step 908, the inner diameter “ID1” of the hollow tube 210 is expanded in order to mechanically secure the hollow tube 210 with the plate 208. One of ordinary skill in the art will appreciate that the diameter of the mandrel 500 may be relatively larger than the inner diameter “ID1” of the hollow tube 210. This may result in the expansion of the inner diameter “ID1” the hollow tube 210 when the mandrel 500 is passed through it. To this end, the interference fit between the outer surface 702 of the hollow tube 210 and the inner surface 704 of the aperture 302 is created at the joint 700. It should be understood that the disclosure described herein can be used in a variety of applications making use of the platform grating 204.
While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by the modification of the disclosed machines, systems and methods without departing from the spirit and scope of what is disclosed. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof.

Claims

What is claimed is:

1. A platform grating comprising:

an array of plates placed in a spaced apart arrangement, wherein each of the array of plates includes a plurality of apertures, the apertures of one plate provided in transverse alignment with the apertures in the adjacent plate; and

an array of hollow tubes positioned within the apertures provided in the array of plates, wherein each of the array of hollow tubes is mechanically connected to the array of plates.

2. The platform grating of claim 1, wherein each of the array of hollow tubes is mechanically connected to the array of plates by interference fit within one or more of the plurality of apertures.

3. The platform grating of claim 2, wherein each of the array of hollow tubes includes an outer surface in cooperation with an inner surface of the one or more of the plurality of apertures.

4. The platform grating of claim 2, wherein each of the array of hollow tubes includes a pair of shoulders in cooperation with a first side surface and a second side surface of one or more of the array of plates adjacent one or more of the plurality of apertures.

5. The platform grating of claim 2, wherein the interference fit is created by expanding each of the array of hollow tubes, whereby a diameter of the hollow tube is 3 to 7 percent greater after the expansion.

6. The platform grating of claim 2, wherein the interference fit is created by expanding each of the array of hollow tubes, whereby a wall thickness of the hollow tube is 1 to 5 percent smaller after the expansion.

7. The platform grating of claim 4, wherein the interference fit is created by expanding each of the array of hollow tubes, whereby a shoulder height is 0.5 to 1.5 percent of a wall thickness of the expanded hollow tube.

8. The platform grating of claim 1, wherein the hollow tube is made of metal.

9. The platform grating of claim 1, wherein the plate is made of metal.

10. A method of manufacturing a platform grating, the method comprising:

providing a plurality of apertures in each of an array of plates;

arranging each of the array of plates in a spaced apart arrangement, the apertures of one plate provided in transverse alignment with the apertures in the adjacent plate;

positioning an array of hollow tubes through the provided apertures, wherein an outer diameter of the hollow tube is less than a diameter of the aperture; and

expanding the diameter of each of the array of hollow tubes to mechanically secure the hollow tube with the plate.

11. The method of claim 10 further comprising directing a mandrel through a full length of each of the array of hollow tubes.

12. The method of claim 11, wherein directing the mandrel through each of the array of hollow tubes further comprises:

attaching a cable to one end of the mandrel; and

pulling the mandrel and the attached cable through the full length of each of the array of hollow tubes.

13. The method of claim 11, wherein directing the mandrel through each of the array of hollow tubes further comprises pushing the mandrel through the full length of each of the array of hollow tubes using a hydraulic press.

14. The method of claim 10, wherein the inner diameter of the hollow tube is 3 to 7 percent greater after the expansion.

15. The method of claim 10, wherein a wall thickness of the hollow tube is 1 to 5 percent smaller after the expansion.

16. A machine comprising:

a power source; and

a platform grating provided on the machine, the platform grating comprising:

17. The machine of claim 16, wherein each of the array of hollow tubes is mechanically connected to the array of plates by interference fit within one or more of the plurality of apertures.

18. The machine of claim 17, wherein each of the array of hollow tubes includes an outer surface in cooperation with an inner surface of the one or more of the plurality of apertures.

19. The machine of claim 17, wherein each of the array of hollow tubes includes a pair of shoulders in cooperation with a first side surface and a second side surface of one or more of the array of plates adjacent to one or more of the plurality of apertures.

20. The machine of claim 16, wherein the hollow tube is made of a metal.