Material handling system including dual track assembly and method of operating same

• US 20090277747A1
• Filed: 01/09/2009
• Published: 11/12/2009
• Est. Priority Date: 05/09/2008
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Spangler, John M., Bilson, David G.
• Granted Patent: US 8,127,687 B2
• Time in Patent Office: Days
• US Class Current: 198/345.300
• CPC Class Codes: B65G 35/066 the bar or the tube being provided with a helical or annular channel

Abstract

A lobed bushing is provided for a track assembly of a track-type machine. The track assembly includes a first chain and a second chain coupled together with a track pin. A bushing, defining a longitudinal axis, includes a central bore oriented along the longitudinal axis and extending from a first end of the bushing to a second end of the bushing for receiving the track pin. The bushing includes a first lobe positioned at a first location about the longitudinal axis and a second lobe positioned at a second location about the longitudinal axis that is less than about 180° from the first location. The first end of the bushing has a substantially cylindrical shape.

Claims

1. A material handling system, comprising:

a first track assembly configured to transport a forward trolley along a first path;

a second track assembly configured to transport a trailing trolley along a second path, the second path being parallel to the first path; and

a carrier configured to support an article and having a first end pivotably supported by the forward trolley and a second end pivotably supported by the trailing trolley.

2. The material handling system of claim 1, wherein the first track assembly and the second track assembly define a transportation path, the forward trolley and the trailing trolley being spaced apart along the transportation path.

3. The material handling system of claim 2, wherein each of the first track assembly and the second track assembly includes a friction drive system.

4. The material handling system of claim 3, wherein each of the first track assembly and the second track assembly includes a composite beam including an upper rail and a lower track connected through a plurality of spaced apart transverse members, the lower track defining two parallel channels.

5. The material handling system of claim 4, wherein each of the forward trolley and the trailing trolley includes an upper set of wheels and a lower set of wheels, the lower set of wheels being received within the two parallel channels.

6. The material handling system of claim 5, wherein the friction drive system includes a drive tube positioned between the upper rail and the lower track such that the upper set of wheels are in frictional engagement with the drive tube.

7. The material handling system of claim 4, wherein each of the plurality of transverse members includes an inverted U-shaped cross-section defining a pair of free ends, each of the pair of free ends supporting a C-shaped channel of the lower track.

8. The material handling system of claim 7, wherein the upper rail includes a T-shaped cross-section defining a central web and a transverse support flange, the central web being received within a vertically aligned slot of an upper portion of each of the plurality of transverse members.

9. The material handling system of claim 7, wherein the upper rail includes a pair of oppositely oriented structural members, each of the pair of oppositely oriented structural members having a vertically oriented web secured to each of the plurality of transverse members.

10. The material handling system of claim 9, further including a horizontally aligned support plate secured to each of the pair of free ends of the plurality of transverse support members.

11. A method of operating a material handling system, comprising:

transporting an article along the material handling system, at least in part, by;

supporting the article on a carrier, the carrier having a first end pivotably supported by a forward trolley and a second end pivotably supported by a trailing trolley;

moving the forward trolley along a first track assembly defining a first path; and

moving the trailing trolley along a second track assembly defining a second path, wherein the first path and the second path are parallel.

12. The method of claim 11, further including spacing the forward trolley and the trailing trolley along a transportation path defined by the first track assembly and the second track assembly.

13. The method of claim 12, wherein each of the first and second moving steps is performed using a friction drive system.

14. The method of claim 13, further including supporting the carrier with a first composite beam of the first track assembly and a second composite beam of the second track assembly, each of the first composite beam and the second composite beam including an upper rail and a lower track connected through a plurality of spaced apart transverse members.

15. The method of claim 11, further including traveling a greater distance with one of the forward trolley and the trailing trolley when transporting the carrier around a curve.

16. A manufacturing line, comprising:

a plurality of manufacturing modules positioned in series and defining at least one main path through the manufacturing line, each manufacturing module including a material handling system for transporting an article along the main path; and

the material handling system of at least one manufacturing module including;

a first track assembly configured to transport a forward trolley along a first path;

a second track assembly configured to transport a trailing trolley along a second path, the second path being parallel to the first path; and

a carrier configured to support the article and having a first end pivotably supported by the forward trolley and a second end pivotably supported by the trailing trolley.

17. The manufacturing line of claim 16, wherein the forward trolley and the trailing trolley are spaced apart along the main path.

18. The manufacturing line of claim 17, wherein each of the first track assembly and the second track assembly includes a friction drive system.

19. The manufacturing line of claim 18, wherein each of the first track assembly and the second track assembly includes a composite beam including an upper rail and a lower track connected through a plurality of spaced apart transverse members, the lower track defining two parallel channels.

20. The manufacturing line of claim 19, wherein each of the forward trolley and the trailing trolley includes an upper set of wheels and a lower set of wheels, the lower set of wheels being received within the two parallel channels and the upper set of wheels being in frictional engagement with a drive tube positioned between the upper rail and the lower track.