IMPROVED DIGGING CHAIN CONTINUOUS BULK UNLOADER/RECLAIMER

Abstract: A continuous bulk unloader/reclaimer that utilizes a bucket conveyor digging chain (18) to remove material (16) from the holds (14) of vessels such as ships, barges, railroad cars, pits, stockpiles etc. The conveyor chain (18) is comprised of an elastomer bushing (32) that allows for the bucket conveyor chain (18) to circulate at high speeds with increased durability.

Description: Improved Digging Chain Continuous Bulk Unloader/Reclaimer Related Applications This is a continuation in Part of my prior co-pending Appli¬ cation Serial # 07/668,883 filed 03/13/91 for "Continuous Unloader" now pending, and Application Serial # 07/668,957 filed 03/13/91 for "Chain and Sprocket Combination" now allowed, both of which are incorporated by reference herein in full. Background—Field Of Invention This invention relates to continuous bulk unloaders/reclaim- ers (herein afterward referred to as continuous unloaders) that use a digging chain to both reclaim and convey granular or powder bulk materials such as grains, coal, ores, ferti¬ lizers, rocks, soil, etc. from pits, stockpiles, and the cargo holds of vessels such as ships, barges, railcars, and the like. Background—Description Of Prior Art U.S. Patent #3,144,142 (1964) introduced an unloader for ships that utilized a digging chain that reclaimed cargo as it drug through the cargo in a loop. This patent utilized a mechani¬ cal chain similar to bicycle type chains comprised of metal links, pins, bushings, rollers, sprockets, etc. with buckets attached. U.S. Patent #3,378,/l30 (1968) by the same inventor improved upon this unloader by using wire rope segments to replace the bicycle type chain. This was done because the wear of the chain's pins and bushings made the original invention impractical for most materials. It was also done in an effort to increase the speed of circulation of the chain of buckets because bicycle type chains of the size required for unloaders have a speed limit of about 200 feet per minute. These speeds cause the size and weight of these unloaders to be impractical for most applications. Low chain speeds are required because of the detrimental dynamic effects resulting from a phenomenon known as chordal action. To date this second invention has had little commercial success because the wire ropes experience high wear and the speed of circulation is not much higher than that of ordinary bicycle type chains. Today there are a few unloaders in operation that utilize the method of dragging the buckets through the material because it has many advantages, however in general these unloaders have reverted back to utilizing bicycle type chains with buckets attached similar to the method taught in the first invention U.S. #3,144,142. In general, these unloaders are restricted to working in non-abrasive materials because of the chain's pin and bushing wear. Also, they are large and heavy due to the slow circulation speeds of the chain. I introduced in my U.S. Patent Application # 7/668,957 a far superior unloader that utilizes an elastomer bushed chain that allows for high speed circulation of the chain which allows for a smaller unloader to do the same amount of work as a much larger unloader utilizing a bicycle type chain. SUBSTITUTE SHEET In my U.S. Patent Application # 7/668,883 I introduced a chain and sprocket arrangement that utilizes an elastomer bushed chain and special sprocket that allows for conveyors to operate at increased speeds. The present invention will introduce additional means and methods for improving upon my two previous inventions. Objects and Advantages Accordingly I claim the following as my objects and advantages of the invention: To introduce a much improved digging chain type continuous bulk unloader/reclaimer that combines the digging chain principal with an elastomer bushed chain that will operate faster and with much reduced wear in a variety of materials. To introduce an elastomer tire that is especially suitable for supporting, circulating, and tracking the elastomer bushed chain. To introduce a method for the easy adjustment of the chains torsional resistance. To introduce a method for decreasing the size of elastomer bushed chains. To introduce a method for increasing the life of elastomer bushings used for chains. To introduce a method for assisting a wheel in changing the direction of a chain. Readers will find further objects and advantages of the invention from a consideration of the ensuing description and the accompanying drawings. SUBSTITUTE SHEET Drawing Figures: Figure 1 shows a schematic drawing of a continuous bulk unloader/reclaimer utilized to unload cargo from the hold of a ship. Figure 2 shows a schematic view of the bucket chain portion of the unloader adjacent to the cargo. Figure 3 shows a cross sectional view through the chain along line 3-3 of figure 2. Figure 4 shows a cross sectional view along lines 4-4 of Figure 2. It is a cross sectional view through the chain and support wheel. Figure 5 shows an especially useful wheel arrangement to assist in removing the cargo from the buckets and allows for a much more compact unloader. Figure 6 shows an elastomer bushing's twist angle vs. torque curve. Figure 7 shows an elastomer bushing's twist angle vs. torque curve. Figure 8 shows a schematic sectional view of the chain more or less along line 8-8 of figure 3. Figure 9 shows a schematic sectional view of the chain more or less along line 8-8 of figure 3. Figure 10 shows an elastomer bushing's twist angle vs. torque curve. Figure 11 shows a schematic sectional view of the chain more or less along line 8-8 of figure 3. Figure 12 shows an elastomer bushing's twist angle vs. torque curve. Figure 13 shows a schematic view representing the interface of the chain and wheel. Figure 14 shows a schematic sectional view of the chain more or less along line 8-8 of figure 3. Drawing Reference Numerals: 1 secondary loop 10 support structure 12 bucket conveyor frame 14 discharge conveyor 15 upper wheel 16 vessel's hold 17 cargo 18 bucket conveyor chain 19 primary loop of bucket conveyor - used for reclaiming 20 exit wheel 1 guide wheel 22 gather wheel 23 bucket 24 outer link 5 axis of outer link 6 pin 8 tube 0 inner link 1 axis of inner link 2 elastomer bushing 3 motor 4 rim 5 axle SUBSTITUTE SHEET 36 elastomer tire 37 additional wheel 38 preset angle 39 preset angle 40 operational range of twist 41 dashed line 42 non-elastic zone 43 heat zone 44 direction of assembled curvature 45 wheel's direction of curvature 46 wheel 48 locking screw Description Of The Invention Fig. 1 shows a continuous unloader according to the preferred embodiment of the invention. The continuous unloader com¬ prises a support structure 10 which supports a bucket conveyor 12. The bucket conveyor 12 is lowered into a vessel's hold 16 where it reclaims, elevates, and transfers the cargo 17 to a discharge conveyor 14 which removes the cargo 17 from the unloader for storage, etc. Fig. 2 shows a schematic detail of the bucket conveyor 12. The exit wheel 20 directs the bucket conveyor chain 18 outward to bucket guide wheel 21. Bucket guide wheel 21 directs the chain downward into a primary loop 19 which is used to fill the buckets 23 by dragging them through the cargo 17. After traveling through this loop 19 the bucket conveyor chain 18 is gathered by gather wheel 22 and directed to an upper wheel 15. The cargo is then discharged onto the discharge conveyor 14. The upper wheel 15 directs the chain 18 downward to the exit wheel 20 completing one complete circuit. The chain's 18 flight from exit wheel 20 to guide wheel 21 also sags downward to form a secondary loop 1. This loop is kept small by the weight of the primary loop 19 or by providing a means for driving wheel 21 which would cause it to function as a UTE SHEET tensioning wheel. It has been found through testing that it is impossible to remove the secondary loop by utilizing the chain's 18 torsional spring force described below. Referring to Fig. 3, the bucket conveyor chain 18 is comprised of a pair of outer links 24 which are connected to a pin 26 at each end. Pin 26 passes through a tube 28. Tube 28 is connected to a pair of inner links 30. An elastomer bushing 32 is interposed between the pin 26 and the inner periphery of the tube 28. The elastomer bushing 32 is an elastomer ring where the inner periphery of the ring is attached to the pin 26 and its outer periphery is attached to the inner periphery of the tube 28. The elastomer bushing 32 is interposed between the pin 26 and the tube 28 in such a manner so that it is compressed radially. The said compression causes a frictional force to exist thus providing the said attachment of the outer periphery of the elastomer bushing 32 to the inner periphery of the tube 28. The said attachment of the inner periphery of the elastomer bushing 32 to the pin is provided by vulcanization, bonding, or friction due to compression. When an elastomer bushing is constructed as specified above it also functions as a torsional spring that resist hinging of adjacent links 24 and 30. Buckets 23 are attached to the bucket conveyor chain 18. Referring to Fig. 4, the bucket conveyor chain 18 is circu¬ lated by a wheel comprised of a rim 34, an elastomer tire 36 which can be solid or pneumatic. The inner link 30 and the outer link 24 ride on the elastomer tire 36. The shell of the bucket 23 can be used with the side of the elastomer tire 36 as a guide for preventing the bucket conveyor chain from derailing from the tire 36. Referring to Fig. 5, an alternative arrangement for the circulation of the bucket conveyor chain 18 is shown. In this arrangement an additional wheel 37 has been added adjacent to and just below upper wheel 15, this wheel 37 forces the bucket SUBSTITUTE SHEET conveyor chain 18 to move slightly under upper wheel 15 on its way down to exit wheel 20. This aids in discharging the buckets. It also allows for the construction of a more compact unloader because it allows for the flight of buckets going up and the flight of buckets going down to be located closer together. Operation Of The Invention As shown in Fig. 1, the support structure 10 holds the bucket conveyor 12 adjacent to the cargo 17 in the vessel's hold 16. The support structure 10 can be mobile or fixed. It functions to allow the bucket conveyor to be movable inside the vessel's hold 16, and from hold to hold, and from one vessel to another. The bucket conveyor chain 18 is supported and circulated by the wheels 15, 20, 21, 22 as shown in Fig. 2 or wheels 15, 37, 20, 21, 22 as shown in Fig. 5. The said wheels can be powered or idlers as required. The buckets 23 of the bucket conveyor chain 18 drag through the cargo 17 as they traverse the loop 19. The bucket conveyor chain 18 then elevates the cargo up and over wheel 15 where a combination of gravity and centrifugal force are used to dump the cargo out of the buckets 23 onto the discharge conveyor 14 where it is removed from the unloader. The bucket conveyor chain 18 as detailed in Fig. 3 hinges about its hinge pin 26 as it circulates about the wheels 15, 20, 21, 22 or 15, 37, 21, 22, 23. More specifically as the chain 18 approaches and enters a wheel it is forced to hinge about its hinge pin 26. Hinging causes the elastomer bushing 32 to be stressed so that it elastically deforms allowing the hinging to take place by deformation of the elastomer materi¬ al. Because hinging occurs by deformation of the elastomer material there is no sliding friction. This eliminates the need for lubrication. This also eliminates wear due to the ingress of dirt and other abrasive materials into the pins and HEET bushings of bicycle type chains. Deformation of the elastomer during hinging makes the elastomer bushing also function as a torsional spring. The torsional spring is designed to resist hinging with enough force to prevent the chain from freely slamming onto the sprocket as it enters and seats on the sprocket. This is because the spring characteristics of the elastomer bushing acts to reduce the impact velocity of the chain's links with the wheel. Detrimental pounding can for all practical purposes be eliminated if the torsional spring force is strong enough to reduce substantially the impact velocity as described in my patent applications 7/668,957 and 7/668,883. It has been found that for conveyor chains which have a pitch of 3 inches or greater (pitch is the distance from one pin to an adjacent pin) and travel at speeds of 300 feet per minute or higher require a spring that exerts a torsional force greater than or equal to 10 foot pounds. Hinging occurs anytime a wheel causes the chain to bend. The reduction or elimination of pounding which is due to chordal action allows for higher operating speeds of the chain. Higher chain speeds allow for smaller chains and a practical unloader size. Referring to Fig. 6, a graph is given that illustrates the typical shape of a twist angle vs. torque curve for a hinge joint comprised of an elastomer bushing. The slope of the curve represents the spring constant for the elastomer bushing and corresponding hinge joint. In general the slope is relatively flat for small twist angles. It becomes steeper as the amount of twist is increased. If the angle from Ao through A« represents the operational range of twist 40 (the back and forth range of twist the bushing and corresponding hinge undergoes during operation) the maximum torque will be Ta at A». Referring to Fig. 7, since it is desirable to strongly resist hinging of the chain in order to allow for the reduction or elimination of pounding and higher chain speeds it is of great advantage to shift the operational range of twist 40 to the right as shown from Ac to A« ' where the SUBSTITUTE SHEET corresponding torques range from To* to «' which are greater than the torques To to T«» of Fig. 6. Referring to Fig. 8, this is accomplished by assembling the chain as shown where the axis 25 of outer link 24 is posi¬ tioned at position An which is at a preset angle 38 from the axis 31 of adjoining inner link 30. Therefore, when the link 24 has rotated relative to link 30 to Ac and into the operational range of twist 40 the bushing and corresponding hinge will resist twist with a torque which is higher than if it had not been preset. The preset angle 38 should be set so that a given bushing and its corresponding hinge can resist twist (hinging of the chain) with enough force to reduce or eliminate detrimental pounding due to chordal action to an acceptable level. Presetting the bushing as such allows for an elastomer bushing to deliver more resistance to twist than it would if it was much larger and had not been preset. This invention allows for a reduction in chain size and weight. Referring to Figures 8 and 13, another reason for presetting the relative position of adjoining links with an angle is so that when the chain 18 travels about a wheel 46 and the direction of its assembled curvature 44 matches the direction of curvature 45 of the wheel 46 the preassembled curvature of the chain 18 will assist the wheel in changing the direction of the chain 18. This is so because the chain 18 tries to wrap itself around the wheel 46. Referring to Fig. 9, a cross sectional view of an elastomer bushed chain is shown. In general, if link 24 is twisted from position Ax relative to link 30 to position As and then released, link 24 will immediately spring back to position A 2 which is to the right of Ax. (In other words, the elastomer bushing and corresponding hinge do not behave as a pure spring, but as a combination spring and dampener. ) If the SUBSTITUTE SHEET operational range of twist 40 is from Ax to A3 heat will be generated in the elastomer bushing as the link 24 is forced to move back to Ax from As. In this non-elastic angular zone 42 between A2 and Ax the elastomer bushing and corresponding hinge is generally nonelastic and the energy required to twist it is lost to heat which is generated in the elastomer material of the bushing. This heat can cause degradation of the elastomer and premature failure of the elastomer bushing 32. Referring to Fig. 10, the dashed line 41 represents the curve that the bushing and corresponding hinge's twist vs. torque curve takes when released from a torqued state. The shaded heat zone 43 represents the zone where heat is generated. To overcome generation of heat the bushing should be assembled as shown in Fig. 11, with the axis 25 of the link 24 set at a relative position which is located at a preset angle 39 with respect to the axis 31 of link 30. The preset angle 39 should be set so that the operating range of twist 40 from Ai ' to A 3' of the bushing as it twist back and forth stays outside of the non-elastic zone 42 from Ax to As. This is graphically shown in Fig. 12. In other words, to extend bushing life the chain should be preset so that the bushing does not twist in the nonelastic zone 42 of the bushing's twist angle vs. torque curve. Referring to Fig. 14, the adjustment of preset angles is made simple by constructing the tube 28 to attach to the inner link plate 30 by a slip fit into a bore drilled through the end of the inner link 30. Thereby any preset angle can be made by simply twisting the adjoining outer link 24 relative to link 30 to any angle desired by letting the outer periphery of the tube 28 spin in the bore. Once the desired preset angle has been achieved the locking screw 48 is tightened, thereafter any additional twisting of adjoining links will be resisted by the elastomer bushing. This arrangement also allows for the easy assembly and disassembly of the elastomer bushing 32, pin 26, and tube 28 which .can be assembled as a single unit prior to attaching to the links 30. SUBSTITUTE SHEET Referring to Figures 2 and 4, the elastomer tires 36 which comprise the wheels 15, 20, 21, 22 are rugged and long lasting and together with the high speed action of the bucket conveyor chain 18 eliminate the need for metal sprockets and provide long trouble free operation. Sprockets are not required because with the higher conveyor chain speeds 18 the same amount of work can be done with lower line loads. This allows for the friction between the tire 36 and chain 18 to be of adequate magnitude to provide traction for propelling the chain when a motor 33 is attached to the tire 36 via the axle 35 and rim 34. The elastomer tire 36 also serves as a clutch mechanism that prevents excessive line loads should the bucket conveyor chain 18 snag. While the above description contains many specificities, the reader should not construe these as limitations on the scope of the invention, but merely as exemplifications of preferred embodiments thereof. Those artisans skilled in the art will envision many other possible variations that are within its scope. For example skilled artisans will readily be able to change the dimensions and shapes of the various embodiments. The elastomer bushing can be made of different flexible materials. The buckets can be of many different shapes and attached anywhere to the chain. Wheels can be arranged in a variety of ways. Alternate means can be used to reclaim and feed cargo to the bucket conveyor. The elastomer bushing can be comprised of a plurality of axially spaced elastomer donuts as is described in prior art relating to tracked vehicles. The tube 28 can be substituted by boring a hole in a link for inserting the elastomer bushing directly into the link, artisans will be able to envision combining the elastomer bushing with metal bearings to increase the load carrying capacity of the chain. The elastomer bushing can also be used as a seal to protect metal bushings from contaminants and to hold lubricants. The shape of links can also be varied. Also, SUBSTITUTE SHEET the support structure can be of any type or variety suitable for holding and placing the bucket conveyor in the material to be handled. The discharge conveyor can be of any type required to remove the cargo from the bucket conveyor. The improvements herein can also be used for the tracks of tracked vehicles. Also, the means and techniques described for increasing chain performance for a chain entering a wheel can also be used to increase chain performance as it exits a wheel. Accordingly the reader is requested to determine the scope of the invention by the appended claims and their legal equivalents, and not by the examples which have been given. 1TUTE SHEET Improved Digging Chain Continuous Bulk Unloader/Reclaimer Abstract: A continuous bulk unloader/reclaimer that utilizes a bucket conveyor digging chain 18 to remove material 16 from the holds 14 of vessels such as ships, barges, railroad cars, pits, stockpiles etc. The conveyor chain 18 is comprised of an elastomer bushing 32 that allows for the bucket conveyor chain 18 to circulate at high speeds with increased durability.

Claims: Claims; I Claim: 1. A continuous bulk unloader/reclaimer comprised of: a support structure, said support structure having a means for supporting a bucket conveyor, a discharge conveyor, said discharge conveyor having a means for being connected to said bucket conveyor, said bucket conveyor being comprised of a plurality of wheels, said wheels having a means for supporting and circulating a bucket conveyor chain about said wheels to form an endless train, a means connected to the bucket conveyor near its lower end for deflecting the said bucket conveyor chain outward and down to form a loop, said bucket conveyor chain contacting the material to be reclaimed while traversing the said loop, wherein said bucket conveyor chain is comprised of a series of links, adjoining said links having a means for being connected together to form a hinge, a means for connecting a spring to said adjoining links to resist hinging of said adjoining links as they pivot about said hinges. 2. The apparatus of claim 1 above wherein said means for connecting a spring to adjoining said links is comprised of: a means for providing a bore through the end of a said link, a pin affixed to a said adjoining link passing through said bore, said bore having an elastomer ring interposed, said elastomer ring being affixed at its outer surface to the interior surface of said bore, said elastomer ring being affixed at its inner surface to the exterior of said pin. 3. The apparatus of claim 1 above wherein said wheels are SUBSTITUTE SHEET comprised of: a rim with means for being supported by an axle, said axle having means for being supported by said bucket conveyor, an elastomer tire having means for being supported upon said rim, wherein said tire supports and directs portions of said bucket conveyor chain. 4. The apparatus of claim 2 above wherein said wheels are comprised of: a rim with means for being supported by an axle, said axle having means for being supported by said bucket conveyor, an elastomer tire having means for being supported upon said rim, wherein said tire supports and directs portions of said bucket conveyor chain. 5. A bucket conveyor comprised of: a frame, said frame having a means for supporting a plurality of wheels, said wheels having a means for supporting and circulating a conveyor chain, wherein said bucket conveyor chain is comprised of a series of links, adjoining said links having a means for being connected together to form a hinge, a means for connecting a spring to adjoining said links to resist hinging of said adjoining links as they pivot about said hinge, wherein said wheels or comprised of a rim with means for being supported by an axle, said axle having means for being supported by said bucket conveyor, an elastomer tire having means for being supported upon said rim, wherein said tire supports and directs portions of said bucket conveyor chain. 6. The apparatus of claim 5 wherein said elastomer tire contacts the said chain with enough frictional force to provide the tractive effort required to propel the chain. 7. A method for decreasing chordal action and increasing the speed of a conveyor chain when engaging and circulating about a wheel comprised of: wherein said chain is comprised of a series of links, adjoining said links having a means for being connected together to form a hinge, a means for connecting a spring to said adjoining links such that said spring resist hinging about said hinge, said adjoining links being set at an angle relative to each other at assembly in order to preload said spring. 8. A method for decreasing chordal action dynamics of a conveyor chain when engaging a wheel comprising: said chain being comprised of a series of links, adjoining links being connected by a hinge, said hinge being comprised of, a means for providing a bore through the end of a said link, a pin affixed to a said adjoining link passing through said bore, said bore having an elastomer ring interposed, said elastomer ring being affixed at its outer surface to the interior surface of said bore, said elastomer ring being affixed at its inner surface to the exterior of said pin, said adjoining links being set at an angle relative to each other at assembly in order to preload said bushing thereby increasing resistance to hinging of the said chain about said wheel. 9. A method for decreasing the size of a conveyor chain com¬ prised of: SUBSTITUTE SHEET said chain being comprised of a series of links, adjoining links being connected by a hinge, said hinge being comprised of, a means for providing a bore through the end of a said link, a pin affixed to a said adjoining link passing through said bore, said bore having an elastomer ring interposed, said elastomer ring being affixed at its outer surface to the interior surface of said bore, said elastomer ring being affixed at its inner surface to the exterior of said pin, said adjoining links being set at an angle relative to each other at assembly. 10. A method for increasing the life of a conveyor chain comprised of: said chain being comprised of a series of links, adjoining links being connected by a hinge, said hinge being comprised of, a means for providing a bore through the end of a said link, a pin affixed to a said adjoining link passing through said bore, said bore having an elastomer ring interposed, said elastomer ring being affixed at its outer surface to the interior surface of said bore, said elastomer ring being affixed at its inner surface to the exterior of said pin, said adjoining links being set at an angle relative to each other at assembly in order to avoid detrimental heat genera¬ tion in the elastomer ring during operation. 11. A method for assisting a conveyor chain change direction as it travels about a wheel comprised of: wherein said chain is comprised of a series of links, adjoining said links having a means for being connected together to form a hinge, a means for connecting a spring to the ends of said adjoining SUBSTITUTE SHEET links such that said spring resist hinging about said hinge, said adjoining links being set at an angle relative to each other at assembly so that the curvature of the chain and the curvature of the wheel travel in the same direction. 12. A conveyor chain traveling over a wheel: said chain being comprised of a series of links, adjoining links being connected by a hinge, said hinge comprising a pin affixed to one said chain link passing through a tube, said tube having an elastomer ring interposed, said elastomer ring being affixed at its outer surface to the interior of said tube, said elastomer ring being affixed at its inner surface to the exterior of said pin, said tube being supported by a bore drilled within a said adjoining link, said tube being movable within said bore for adjustment, a means for locking the said tube in position in the said bore once the position of the said elastomer ring has been set. 13. A method for increasing the operating speed of a bucket conveyor chain which has a pitch equal to or greater than 3 inches at speeds of over 300 feet per minute, wherein said chain is comprised of a series of links, adjoining said links having a means for being connected together to form a hinge, a means for connecting a spring to said adjoining links «uch that said spring resist hinging about said hinge, wherein said spring is sized such that it resist said hinging with a minimum torque of 10 foot pounds when said adjoining links are fully hinged in their normal mode of operation. 14. A continuous bulk unloader/reclaimer comprised of: a support structure, said support structure having a means for supporting a bucket SUBSTITUTESHEET

Inventors: SEYMOUR TIMOTHY HARRISON, SEYMOUR, TIMOTHY, HARRISON
Applicants: HARRISON SEYMOUR T, SEYMOUR, TIMOTHY, HARRISON
Application year: 1992
Main classification: B63B27
IPC codes: B63B25, B65G17, B65G65, F16G13