Cast infeed conveyor chain

Abstract

A cast conveyor chain segment including a leading edge including a hinge pin aperture to receive a hinge pin for connecting the cast conveyor chain segment to another like cast conveyor chain segment in a forward longitudinal direction, a trailing edge including a hinge pin aperture to receive a hinge pin for connecting the segment to another like segment in a rearward longitudinal direction, and a main body portion extending between the leading and trailing edges. The main body portion has a bottom side including cavities and webbing extending from the leading edge to the trailing edge. The main body portion also has an upper surface extending from the leading edge to the trailing edge. The segment is a monolithic body, cast from a metallic material to include the main body portion, the hinge pin aperture of the leading edge, and the hinge pin aperture of the trailing edge.

Description

CAST INFEED CONVEYOR CHAINCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This patent application claims priority to co-pending U.S. Provisional Patent Application No. 63 / 637,278, filed April 22, 2024, the entire contents of which are incorporated by reference herein.BACKGROUND

[0002] Some material reduction machines such as horizontal grinders include an infeed conveyor to guide material into a processing portion of the machine where the material reduction occurs. The infeed conveyor can be constructed from numerous rows or slats pinned together. Each slat can be constructed as a weldment of many pieces to meet product objectives such as cost, weight, and durability.

[0003] FIG. 1 shows such a grinder 200 of known construction having a processing portion 212 for crushing aggregate material into smaller pieces through repeated blows (e.g., using grinder blocks or a combination of grinder blocks and cutter elements as the primary comminuting mechanism), and an infeed portion 230 upstream. The infeed portion 230 has a powered conveyor 235a at the infeed floor 235 such that the aggregate material passes between the feed roller 232 and the powered conveyor 235a before reaching the processing portion 212. FIGS. 2-4 illustrate the construction of the conveyor 235a in greater detail. As shown in FIG. 2, a plurality of slats 240 are hingedly coupled to each other to form a loop. One of the slats 240 is removed in FIG. 2, and the individual slat 240 is shown in isolation in FIGS. 3 and 4.

[0004] As shown in FIGS. 3 and 4, the conveyor slat 240 includes a top sheet 242, a pair of width-wise opposed end plates 244, a first group of cylindrical hinge members 246 along a leading end of the slat 240, a second group of cylindrical hinge members 248 along a trailing end of the slat 240, a plurality of truss members 250 connecting the hinge members 246, 248 of the first and second groups, a plurality of lateral reinforcements 252 extending between adjacent ones of the truss members 250, and a plurality of lugs or cleats 254 on a working outer surface of the top sheet 242. The various pieces of each slat 240 are individually manufactured and then joined together as a weldment via a plurality of welding processes. The conveyor of known construction illustratedin FIGS. 2 - 4 contains a high number of parts, can be challenging to manufacture, has a relatively short life, and high weight. There is a need for a more economical conveyor.SUMMARY

[0005] In one aspect, the present disclosure provides a cast conveyor chain segment comprising a leading edge including at least one hinge pin aperture configured to receive a hinge pin for connecting the cast conveyor chain segment to another like cast conveyor chain segment in a forward longitudinal direction, a trailing edge including at least one hinge pin aperture configured to receive a hinge pin for connecting the cast conveyor chain segment to another like cast conveyor chain segment in a rearward longitudinal direction, and a main body portion extending between the leading edge and the trailing edge. The main body portion has a bottom side including open cavities and webbing extending from the leading edge to the trailing edge. The main body portion also has an upper surface extending from the leading edge to the trailing edge. The cast conveyor chain segment is a monolithic body, cast from a metallic material to include the main body portion, the at least one hinge pin aperture of the leading edge, and the at least one hinge pin aperture of the trailing edge.

[0006] In another aspect, the present disclosure provides a conveyor chain comprising a plurality of slats indexed in the forward and rearward longitudinal directions. Each of the plurality of slats includes a plurality of the cast conveyor chain segments arranged in a row. Each one of the plurality of slats extends transverse to the forward and rearward longitudinal directions to define a chain width. Between each adjacent pair of slats of the plurality of slats, a joint including a corresponding hinge pin extends along a hinge pin axis and penetrating both the at least one hinge pin aperture of the leading edge of each cast conveyor chain segment in a first row of the adjacent pair and the at least one hinge pin aperture of the trailing edge of each cast conveyor chain segment in a second row of the adjacent pair. The respective joints connect the plurality of slats together to form a complete loop.

[0007] In another aspect, the present disclosure provides a horizontal grinder comprising an infeed system including the conveyor chain and an infeed table supporting an upper run of the conveyor chain, a comminution system positioned adjacent a downstream end of the infeed system,and a discharge conveyor positioned downstream of the comminution system to receive material therefrom.Other features and aspects of the invention will become apparent by consideration of the following detailed description and accompanying drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1 is a front perspective view of a horizontal grinder according to a known construction.

[0009] FIG. 2 is a perspective view of an infeed conveyor chain of the horizontal grinder of FIG. 1.

[0010] FIG. 3 is a first perspective view of a single slat of the infeed conveyor chain of FIG. 2.

[0011] FIG. 4 is a second perspective view of the slat of the infeed conveyor chain of FIG. 2.

[0012] FIG. 5 is a front perspective view of a horizontal grinder according to the present disclosure.

[0013] FIG. 6 is a perspective view of a frame and an infeed conveyor of the horizontal grinder of FIG. 5.

[0014] FIG. 7 is a perspective view of the frame and the infeed conveyor of FIG. 6 in which a side of the frame is removed to expose more of the infeed conveyor.

[0015] FIG. 8 is a perspective view of the infeed conveyor chain of FIGS. 6 and 7 in isolation.

[0016] FIG. 9 is a perspective view of the frame and the infeed conveyor of FIG. 6, taken from below the infeed conveyor.

[0017] FIG. 10 is a perspective view of a proximal (output) end of the infeed conveyor and a drive pulley coupled to the infeed conveyor chain.

[0018] FIG. 11 is a more detailed perspective view of the proximal (output) end of the infeed conveyor and the drive pulley, showing complementary drive structures of the drive pulley and the conveyor chain.

[0019] FIG. 12 is an exploded assembly view of a portion, in particular two rows, of the infeed conveyor chain of FIG. 8.

[0020] FIG. 13 is a perspective view of the exterior side of a long chain segment of the infeed conveyor chain shown in FIG. 12.

[0021] FIG. 14A is a cross-section of the long chain segment, taken along line 14A — 14A of FIG. 13.

[0022] FIG. 14B is a cross-section of the long chain segment, taken along line 14B — 14B of FIG. 13 and illustrating a molding assembly used to cast the segment.

[0023] FIG. 15 is a perspective view of the interior side of the long chain segment of FIG. 13.

[0024] FIG. 16 is a bottom view of the long chain segment of FIG. 13 showing the interior side.

[0025] FIG. 17 is a perspective view of the exterior side of a short chain segment of the infeed conveyor chain shown in FIG. 12.

[0026] FIG. 18 is a perspective view of the interior side of the short chain segment of FIG. 17.

[0027] FIG. 19 is a bottom view of the short chain segment of FIG. 17 showing the interior side.

[0028] FIG. 20 is a top plan view of two assembled rows of the infeed conveyor chain shown in FIG. 8.

[0029] FIG. 21 is a bottom view of the two assembled rows of the infeed conveyor chain of FIG. 20.

[0030] FIG. 22 is an end view of the two assembled rows of the infeed conveyor chain of FIGS. 20 and 21.

[0031] FIG. 23 is a perspective view of an end portion of one of the assembled rows of the infeed conveyor chain of FIGS. 20-22.

[0032] FIG. 24 is a detail perspective view from under the infeed conveyor, showing a return side roller guide assembly supported by the frame.

[0033] FIG. 25 is a detail perspective view of the proximal (output) end of the infeed conveyor chain where it meets an anvil supported on the frame.

[0034] FIG. 26 is a second detail perspective view of the proximal (output) end of the infeed conveyor chain where it meets the anvil.

[0035] FIG. 27 is a side elevation view of the proximal (output) end of the infeed conveyor where it meets the anvil with tight clearance.

[0036] FIG. 28 is a perspective view of the infeed table wear components supporting the infeed conveyor chain.DETAILED DESCRIPTION

[0037] Before any embodiments, examples, aspects, or features are explained in detail, it is to be understood that those embodiments, examples, aspects and features are not limited in their application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. Other embodiments, examples, aspects, and features are possible and are capable of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

[0038] FIG. 5 shows a horizontal grinder 1 having an infeed system 2, a comminution system 6, and discharge conveyor 5. The horizontal grinder 1 may be configured to be towed by a truck (as shown above), self-propelled by tracks, or stationary. The infeed system 2 includes a feed roller 16, an infeed floor or table 3, and an infeed conveyor 4. The infeed conveyor 4 operates todeliver material from a distal outer end toward the infeed system 2 for feeding to the comminution system 6 (e.g., the infeed conveyor 4 delivers material to the infeed drum). The comminution system 6 operates to crush aggregate material into smaller pieces through repeated blows or cuts. The comminution system 6 can include a grinder drum with hammers and cutting tips (not shown). The small pieces output from the comminution system 6 are carried away from the comminution system 6 and discharged by the discharge conveyor 5. The comminution system 6 represents a processing portion of the horizontal grinder 1, which is one type of material reduction machine to which aspects of the present disclosure may apply.

[0039] The horizontal grinder 1 has a prime mover 13 (FIG. 5) configured to drive the comminution system 6. In some constructions, the prime mover 13 is an internal combustion engine, although alternative and hybrid prime movers are also contemplated. The infeed conveyor 4 includes a conveyor motor 14 (FIG. 5) and a conveyor chain 44 driven to move in a longitudinal direction by the conveyor motor 14. The conveyor motor 14 can be an electric or hydraulic motor, for example. The conveyor motor 14 can be powered directly or indirectly from the prime mover 13 in some constructions (e.g., electric or hydraulic power generated by running the internal combustion engine).

[0040] A grinder frame 15 is shown in FIG. 6 removed from the grinder 1 of FIG. 5. Among other things, the grinder frame 15 supports the infeed table 3 and the infeed conveyor 4. With reference to FIGS. 6-9, the grinder frame 15 further supports an end or idler pulley 9 at a distal or input end 4-1 of the infeed conveyor 4 and a drive pulley 11 at a proximal or output end 4-2 of the infeed conveyor 4. The drive pulley 11 is coupled for rotation to the conveyor motor 14, which is not shown in FIGS. 6-9. The idler pulley 9 may be adjustable on the grinder frame 15 to adjust the distance between respective axes A, B of the idler and drive pulleys 9, 11, and thus the tension in the infeed conveyor chain 44. The axes A, B are generally horizontal during operation of the grinder. The axes A, B are parallel to each other and the spacing therebetween generally defines a length L of the infeed conveyor 4. The length L of the infeed conveyor 4 can also be the assembled span of the infeed conveyor chain 44 as shown in FIG. 8. The length L is roughly half the total unfurled length of the loop in which the infeed conveyor chain 44 is formed. Perpendicular to the length L, the infeed conveyor 4 defines a width W. The width W of the infeed conveyor 4 can also be the width of the infeed conveyor chain 44 as shown in FIG. 8. The drivepulley 11 can engage and drive the infeed conveyor chain 44 entirely within the width W, which is the working width for supporting material. In other words, the infeed conveyor chain 44 does not require or include additional chain drive features along the outboard edges. The nature of engagement between the infeed conveyor chain 44 and the drive pulley 11 is described further below.

[0041] The length L is parallel to a forward feed direction F of the working upper run R1 of the infeed conveyor chain 44, and the width W is perpendicular to the forward feed direction F. Below the working upper run Rl, the infeed conveyor chain 44 includes a return run R2. It should be understood that the two runs Rl, R2 of the infeed conveyor chain 44 are not physically separate portions of the chain 44, but rather separate, two offset paths along which each point along the infeed conveyor 4 will traverse - either from the idler pulley 9 toward the drive pulley 11 (for the working upper run Rl) or returning from the drive pulley 11 back to the idler pulley 9 (for the return run R2). The return run R2 is the slack side, as the drive pulley 11 exerts tension in the upper run Rl to perform the forward, infeed conveying work. Although generally described with reference to operation in the forward feed direction F, which is the normal direction of operation for the conveyor chain 44 to deliver material toward the comminution system 6, it is also noted that the infeed conveyor 4 and chain 44 thereof may be selectively controlled to run in a reverse direction, opposite the forward feed direction F.

[0042] As shown in FIGS. 10 and 11, the drive pulley 11 includes at least one sprocket 52 extending around the drive pulley axis B. The sprocket 52 is configured to engage an interior of the infeed conveyor chain 44 at the output end 4-2 of the infeed conveyor 4. The drive pulley 11 is provided with a plurality of sprockets 52 at spaced apart locations along the widthwise direction (axis B). In the illustrated construction, the sprockets 52 are arranged in pairs. Each pair of sprockets 52 is evenly spaced from an adjacent pair of sprockets 52 along the widthwise direction. In other constructions, each individual sprocket 52 can be evenly spaced from another individual sprocket 52 along the widthwise direction. A positive engagement is formed between each sprocket 52 and the infeed conveyor chain 44 such that slip is not allowed. To facilitate the engagement, each sprocket 52 includes a plurality of drive teeth 53 circumferentially spaced about the axis B. In the illustrated construction, the drive pulley 11 includes a plurality of sprockets 52. Each sprocket 52 is a two-row sprocket including parallel sets of drive teeth 53. The drive teeth53 can have a variety of shapes, including pointed or flat. In some constructions, the drive teeth 53 may be referred to as drive lugs. As described in further detail below, the infeed conveyor chain 44 includes a plurality of solid metal elements, or “chain segments,” linked by hinged connections to enable the infeed conveyor chain 44 to contort and wrap about the drive pulley 11. Such a construction may be known as a slat chain. The infeed conveyor chain 44 is thus flexible, without the materials or components thereof experiencing bending or flexure. The spacing of the sprockets 52 and the construction of the infeed conveyor chain 44 results in even chain loading across the drive pulley 11. Although not separately shown, a similar engagement may be provided between the infeed conveyor 4 and the idler pulley 9 at the input end 4-2 of the infeed conveyor 4.

[0043] The remainder of the disclosure is primarily directed to the make-up of the infeed conveyor chain 44 as discussed in further detail below, beginning with reference to FIG. 12 in which a small section of the infeed conveyor chain 44 is shown as an exploded assembly. Two consecutive rows or slats of the infeed conveyor chain 44 are shown in FIG. 12. These are shown from the side of the chain 44 that forms the outside working surface (sometimes also referred to as the top or outside). The two consecutive rows are also shown assembled in FIG. 20 (top / outside) and FIG. 21 (bottom or underside, which is inside the conveyor chain loop and opposite the outside working surface). Each row of the infeed conveyor chain 44 extends the full width W of the infeed conveyor chain 44, although multiple elements or segments 23, 24 may combine to make up the width W. As shown, the segments include two (e.g., exactly two) types of segments 23, 24. Each segment 23, 24 may be manufactured from ductile iron, cast steel, gray cast iron, nitriding ductile iron, or another suitable material. The two types of segments 23, 24 are distinguished at least in part by their outside dimension in the direction of the conveyor width W. As such, conveyor chain segments 23 of the first type may be referred to as short segments 23 (shown individually in FIGS. 17-19), and conveyor chain segments 24 of the second type may be referred to as long segments 24 (shown individually in FIGS. 13-16). In the illustrated construction, the widthwise span W23 (FIG. 19) of each short segment 23 is one-half the widthwise span W24 (FIG. 16) of each long segment 24. The short segments 23 can be manufactured by cutting one of the long segments 24 in half. In other constructions, the short segments 23 may have a different length relative to the long segments 24 and may be manufactured using an alternative method.

[0044] In constructing the infeed conveyor chain 44, a first one of the rows is constructed from one or more copies of the first type of conveyor segment 23 and one or more copies of the second segment 24 (e.g., two of each). The second one of the rows, which is indexed or offset from the first row along the longitudinal direction of the infeed conveyor 4 (parallel to the forward feed direction F), is constructed from one or more copies (e.g., three) of the second type of conveyor segment 24. The second row is constructed without any of the first (short) type of segments 23. The two rows form complementary leading and trailing edges as described in further detail below, and the trailing edge of the first row is pivotably connected with the leading edge of the second row via a hinge pin 31. The hinge pin 31 may be composed of a hard metal such as quenched and tempered 4140 steel. The hinge pin 31 extends along an axis C (FIGS. 12 and 13) perpendicular to the longitudinal direction of the infeed conveyor 4. The first and second row constructions are repeated such that they alternate throughout the longitudinal direction of the infeed conveyor chain 44 to form a full loop of approximately double the length L.

[0045] Various arrangements and quantities of the short and long segments 23, 24 may be used to form the infeed conveyor chain 44. For example, expressed generically, the first row may be constructed from two short segments 23 (at opposing widthwise ends) and a quantity N of the long segments 24 therebetween. The second row may be constructed from a quantity N+l of the long segments 24, which span between the opposing widthwise ends. In another example, expressed generically, a first and second row may each be constructed from an equal quantity N of the long segments 24 and one of the short segments 23. In other arrangements of the short and long segments 23, 24, the infeed conveyor chain 44 may be formed of only short segments 23 or only long segments 24. The two types of segments 23, 24 (and two complementary types of rows) enable modular construction of various conveyor chains not limited to the exact infeed conveyor chain 44 as shown. Not only can the infeed conveyor chain 44 be constructed of virtually any desired length by repeating the alternating rows with a hinge pin 31 between each row, but conveyors of various different widths can be constructed by varying the quantity N in the expressions above. For the illustrated construction having the width W, the variable N is set as N = 2. Where N varies, a different length of hinge pin 31 may be provided. With just the same two types of cast segments 23, 24 (and appropriate connecting hardware), conveyor widths including but not limited to 10 inches, 30 inches, 50 inches, and 70 inches can all be constructed.

[0046] Each conveyor chain segment 23, 24 includes one or more pin bosses 21, 22 at the leading and trailing edges thereof. In the illustrated construction, each segment 23, 24 includes a plurality of pin bosses 21, 22 at each of the leading and trailing edges thereof. The portion of each chain segment 23, 24 between the leading edge pin boss(es) and the trailing edge pin boss(es) forms a main body portion thereof. In the short chain segments 23, each of the leading and trailing edges includes a first “long” pin boss 21 and a second “short” pin boss 22 shorter than the first pin boss 21. As shown in FIG. 12, the short pin bosses 22 are arranged at the widthwise outer ends of the infeed conveyor 4. In the long chain segments 24, each of the leading and trailing edges includes two long pin bosses 21 and, therebetween, an additional short pin boss 22. In each case, the chain segments 23, 24 include pockets or recesses 54 between the adjacent long and short pin bosses 21, 22. Each recess 54 is sized to accommodate one of the long pin bosses 21 of a chain segment in the adjacent row. The short pin bosses 22 are configured to be accommodated in a gap between two side-by-side chain segments 23, 24 of the adjacent row. Aside from required clearance for assembly, the pin bosses 21, 22 of all the chain segments 23, 24 that combine with one hinge pin 31 to form a row-to-row joint (hinge) occupy the full width W of the infeed conveyor chain 44. The row-to-row j oints connect the plurality of rows together to form a complete loop. One of the chain segments 23, 24 (e.g., one of the short chain segments 23 positioned at the widthwise end) is provided with an aperture or hole 30 in which a retaining element (e.g., roll pin) 29 is received. Another one of the chain segments 23, 24 positioned at the other widthwise end has a second hole 30 in which another retaining element is received. The retaining elements 29 secure the hinge pin 31 such that the hinge pin 31 is entrapped between the retaining elements 29 against removal from the pin bosses 21, 22. The maximum length of the hinge pin 31 is defined by the widthwise distance between the pair of retaining elements 29. The hinge pin 31 can have a length that spans all the chain segments 23, 24. The hinge pin length can be an overwhelming majority of the total chain width (e.g., at least 90 percent or at least 95 percent). Openings (e.g., hinge pin apertures) 40 receive the hinge pin 31 allowing each cast segment 23, 24 to connect to another cast conveyor chain segment 23, 24 in both a forward longitudinal direction and a rearward longitudinal direction relative to axis C. The hinge pin 31 passes through or penetrates the hinge pin apertures 40 formed on the leading and trailing edges of each pin boss 21, 22.

[0047] Rather than having a circular cross-section, the hinge pin apertures 40 in the pin bosses 21, 22 are elongated in the longitudinal direction. In other words, the hinge pin apertures 40 areelongated along an axis D (FIG. 14A, perpendicular to the hinge pin axis C) extending between the leading and trailing edges. The elongated shape of the hinge pin apertures 40 are best observed as viewed along the hinge pin axis C as shown in FIG. 13. The elongated shape facilitates the casting process described below. The elongated hinge pin apertures 40 prevent binding of the hinge pin 31 during assembly and disassembly by providing more room for pin insertion and removal. The hinge pin 31 may freely rotate within the hinge pin apertures 40 relative to the cast segments 23, 24 about the hinge pin axis C. The portion of the outer surface of the hinge pin 31 in contact with pin bosses 21, 22 uniformly experience wear. In the illustrated construction the pin bosses 21, 22 cover the entire outer surface area of the hinge pin 31 excluding small gaps that lie between adjacent pin bosses 21, 22. In other constructions, the cast segments 23, 24 are coupled to one another such that there are no gaps between adjacent pin bosses 21, 22 and the pin bosses 21, 22 cover the entire area of the hinge pin 31. An additional benefit of the elongated hinge pin apertures 40 is evident when the conveyor 4 is operated in reverse (to move material away from the grinder infeed 2). In this scenario, a portion of the conveyor chain 44 may experience a reverse load, i.e., a pushing / compressive force. In previous designs, the compressive force was transferred between the conveyor chain segments by the hinge pins, however, with the infeed conveyor chain 44 having the segments 23, 24, the elongated shape of the hinge pin apertures 40 allows the pin bosses 21 and 22 to contact adjacent side surfaces 55 at the base of the recess 54 before the hinge pin 31 experiences a reverse (shear) load. It is also noted that the leading / trailing surfaces 51 of the pin bosses 21, 22 are rounded or radiused to avoid material pinching as the chain 44 travels around the idler and drive pulley 9, 11.

[0048] As illustrated in FIGS. 15, 16, 18, and 19, the bottoms of the segments 23, 24 include hollow cavities and one or more material webs for strength. Each pin boss 21, 22 includes a pair of webs 32. One of the webs 32 extends widthwise between the interior surfaces of the leading edge of one of the pin bosses 21, 22 and the other one of the webs 32 extends widthwise between the interior surfaces of the trailing edge of the one of the pin bosses 21, 22. An internal pin boss cavity 33 is defined between each pair of webs 32 and the inner surfaces of the one of the pin bosses 21, 22. Similarly, an intermediary cavity 34 is defined by adjacent pairs of webs 32 and adjacent side surfaces 55. The webs 32 provide structural support in the widthwise direction improving the rigidity of the chain segments 23, 24. In the illustrated construction, the pin bosses 21, 22 of the long conveyor chain segments 24 each includes a pair of webs 32. The long pin bosssegments 21 of the short conveyor chain segments 23 include a pair of webs 32 while the short pin boss segments 22 include only a singular web 32 positioned between the interior surfaces of the trailing edge. In other constructions, the pin bosses 21, 22 of either the short or long conveyor segments 23, 24 may include a greater or lesser number of webs 32 than the quantity illustrated. Collectively, the various webs can be referred to as webbing.

[0049] The top conveying surface 41 of the conveyor chain segments 23, 24 may be solid, perforated, pimpled, cleated, or any combination of these features. As shown in the illustrated construction, each conveyor chain segment 23, 24 includes one or more outwardly projecting cleats 28 along the top surface 41. The cleats 28, which may also be referred to as lugs, improve the overall traction to avoid material slippage along the upper run R1 of the infeed conveyor chain 44. As described in further detail below, the top surface 41 of each conveyor chain segment 23, 24 can be convexly curved or “crowned” along the longitudinal direction (i.e., between the leading / trailing edges where the hinge pin apertures 40 are formed).

[0050] The cross-section view of FIG. 14A shows the thickness T of the cast chain segment 24. The thickness T is measured in the main body portion between the leading and trailing edges, excluding the pin bosses 21, 22. The thickness T is measured perpendicular to the crowned upper surface 41. In some constructions, the thickness T is less than 0.25 inch. In some constructions, the thickness T is 0.2 inch. Although not shown separately, the cross-section of the short cast chain segment 23 can be the same as that of FIG. 14A for the long cast chain segment 24. The short cast chain segment 23 can have the same thickness T as the long cast chain segment 24.

[0051] One or more sprocket guide features 43 are formed in each cast chain segment 23, 24. The sprocket guide features 43 guide the lugs 53 of the drive pulley 11 to the desired portion of the cavities 33, 34 on the interior side of each cast segment 23, 24 during operation. The guide features 43 are contoured to guide the lug 53 to the proper location on the chain segment 23, 24. Each sprocket tooth or lug 53 is contacted both in the longitudinal direction and transverse to the guide features 43. For example, the guide features 43 can be formed with a raised profile that interacts with the lugs 53. The raised profile of each of the guide features 43 can form a ramp that increases in height and thus its guiding effect with increased engagement or seating of the drive sprocket lugs 53. In other words, the guide features 43 define a plurality of predetermined contactsurfaces for engagement with the drive sprocket 52, within the overall hollow or concave underside of the chain segments 23, 24. The guide features 43 may be the only drive sprocket contact surfaces within the hollowed area in the underside of the chain segments 23, 24.

[0052] Each of the conveyor chain segments 23, 24 has a monolithic body cast from a metallic material. In some constructions, each of the chain segments 23, 24 is cast (i.e., formed in a casting process to produce a product also known as a “casting”). The cast segments 23, 24 may be made from austempered metal (e.g., ductile iron). More specifically, the cast segments 23, 24 may be made from austempered ductile iron grade 2. This grade of austempered ductile iron is hard enough to have good wear characteristics (wear is relative to hardness, high abrasion resistance) while still having good elongation and toughness and allowing for machinability, such as the machining / drilling of the holes 30 for the retaining elements 29. The austempered ductile iron grade 2 is 110 ksi yield and will resist stretching, denting, wear, and bending better than the metal used for welded conveyor chain segment 240. In other embodiments, the austempered ductile iron may be any of iron grades 1-5 defined by the American Society for Testing and Materials A987 standard. Additionally, the cast chain segments 23, 24 may be hardened after the casting process. Austempered cast iron has a structure of acicular ferrite and high carbon, stabilized austenite known as ausferrite. After austenitization of the metal microstructure, the material is quenched and then held at the quenching temperature for an extended period of time. In other embodiments, other grades and types of ductile iron or cast steel may be used in the casting process to produce the cast segments 23, 24.

[0053] The cast conveyor segments 23, 24 are manufactured using a sand-casting method that includes a mold assembly where half the mold assembly is referred to as the cope 142, the other half of the mold assembly is referred to as the drag 144, and a core 146 (FIG. 14B). The purpose of the core 146 is to create under-cut profiles and cavities that cannot be molded by the cope 142 and drag 144 alone, such as the pin slots 40. The cope mold, drag mold, and core mold may be made of sand. The core 146 is appropriately positioned relative to the cope 142 and drag 144 (i.e., the core 146 is positioned within the cavities of the cope 142 and / or drag 144), then cope 142 and drag 144 are assembled such that a vertical part exists between mold halves. For the design disclosed herein, the cope 142 happens to be the top or outside surface 41 (i.e., the working or conveying surface) and the bottom or inside surface opposite the surface 41 is formed by the drag144, with the core 146 creating the hinge pin apertures40. The mold assembly is then filled with molten metal through an inlet in the mold. After the metal has cooled appropriately, the cope mold 142 and drag mold 144 are disassembled from the casting and the core 146 may be removed from the casting by a variety of methods including tumbling, rods, shot peening, or a combination of these methods. As a result of the repeatability of the casting and machining methods used, the cast conveyor segments 23, 24 have a consistent fit such that a user may reliably assemble the conveyor chain 44. In comparison to the welded cast segments 240, the cast conveyor segments 23, 24 have 33% reduced weight, reduced manufacturing cost, and a 50-100% longer wear life. The wear life improvement is due to the larger bed contact surface of the chain segment and the harder material of the cast segments. Additionally, the cast segments may be heat treated.

[0054] Casting with the use of a core eliminates the need for machining cavities of the cast conveyor segments 23, 24 (such as the hinge pin apertures 40). In some constructions, the only machining of the cast conveyor segments 23, 24 is drilling holes 30 for the retaining elements29 on the end segments 23.

[0055] In contrast to other grinder conveyors, the infeed conveyor 4 also has at least one roller assembly 77 including a plurality of rollers 7 configured to engage the outside of the chain 44 along the return run R2 as shown in FIG. 24. The plurality of rollers 7 are dispersed along the widthwise direction and are mounted on a bracket 8 of the roller assembly 77. As shown in FIGS. 7 and 9, the infeed conveyor 4 can include a plurality of (e.g., three) longitudinally spaced roller assemblies 77. On each roller assembly 77, the individual rollers 7 are offset or staggered longitudinally (see axes C, D in FIG. 24). In particular, the roller assembly 77 can include rollers 7 centered on two parallel, longitudinally offset axes C, D that are spaced by a distance approximately one-half of the longitudinal length of each row of the chain 44 (as measured by the cast chain segments 23, 24 or more accurately the distance between two adjacent hinge pins 31). By staggering the rollers 7, the roller assembly 77 provides consistent support to the return run R2 of the chain 44 and avoids dropping into the dip or seam where the hinge joints are formed between the rows of the chain 44. In other words, when the chain 44 is positioned such that one of the rollers 7 of the roller assembly 77 is at a hinge joint, another one of the rollers 7 is approximately at the longitudinal midpoint of one of the adjacent rows formed by the cast chain segments 23, 24.Additionally, the rollers 7 are positioned to avoid certain features of the conveying surface 41 such as the cleats 28.

[0056] The cast chain segments 23, 24 contain flats 27 for the return rollers 7. These flats 27 on the conveyor chain 44 provide a flat surface as the conveyor chain 44 travels over the return rollers 7 on the return run R2 of the grinder infeed table 3. As shown in FIGS. 23 and 24, the flat surface for a given return roller 7 can be formed by a single flat 27 (e.g., in the middle portion of a large cast chain segment 24) or a combination of two abutting flats 27 at the outer edges of two adjacent cast chain segments 23, 24. The roller assembly 77 can be configured with rollers 7 to engage all or only a selected group of the flats 27 that are provided by the assembled conveyor chain 44.

[0057] With reference to FIGS. 25-27, the second end 4-2 of the infeed conveyor 4 forms a close interface with the frame 15 where the path of the upper run R1 begins to descend and wrap around the outside of the drive pulley 11. At this location, the frame 15 supports an anvil 60. The anvil 60 can be removably secured (e.g., by threaded fasteners) to the frame 15 and replaceable. The anvil 60 includes a conveyor-facing edge, and the conveyor-facing edge can be shaped to conform to features of the chain 44. As such, the conveyor-facing edge can be castellated (i.e., including repeated notches) rather than a straight edge. For example, the anvil 60 can have individual notches that accommodate the cleats 28 such that the remaining portion of the conveyorfacing edge can be positioned closer to the top surface 41. In other words, the clearance gap between the anvil 60 and the working surface of the conveyor chain 44 is less than the height of the cleats 28. The clearance gap can also be kept small by the crowned shape of the top surface 41 of each one of the cast conveyor segments 23, 24. The anvil 60 can be adjustable among multiple positions on the frame 15 to adjust the clearance gap. The crown of the top surface 41 and the cleats 28 function as a cleaning surface removing undesirable material from the working surface of the conveyor chain 44.

[0058] When traversing the drive pulley 11, the sprocket teeth 53 are nested into the engaged cast segments 23, 24, and the top surface 41 of each segment 23, 24 can have a center of curvature located at or near the axis B, which is the center of the drive pulley 11. Thus, the top or outside of multiple slats of the conveyor chain 44, as provided by the top surfaces 41, form a semi-circleprofile around the drive pulley 1 1. The radius of the crown of the top surface 41 can be approximately equal (e.g., within 5%) to the radius defined by the outermost points of the drive pulley 11. The conveyor-facing edge of the anvil 60, or at least a portion thereof, can be similarly angled or curved so that the clearance gap is relatively consistent through the thickness of the anvil 60. In some constructions, the length of the clearance gap is 0.5 inch. In other constructions, the length of the clearance gap may be 0.1 inch to 0.75 inch. The crowning is present across the entire top surface 41, between the leading and trailing edges, not merely at or near the leading and trailing edges. Although the radius of curvature forming the crown can vary between the leading and trailing edges in some constructions, the radius of curvature may be maintained constant across the top surface 41.

[0059] FIG. 28 illustrates the infeed conveyor 4 with the conveyor chain 44 removed. The cast conveyor chain 44, and particularly the underside of the upper run R1 thereof, rides on supports such as plates 64 and / or steel rails on the floor of the infeed area. The plates 64 or other supports may be a replaceable wear part. Alternative materials may be used in some configuration, such as plastics.

[0060] An important feature related to infeed table wear and conveyor chain wear is the amount of area on the conveyor chain 44 that contacts the infeed floor wear parts. When viewed from the underside (FIGS. 16 and 19), each segment 23, 24 has an outer periphery defining an overall area. The overall area or “total coverage area” is a simple two-dimensional figure calculated from the bottom view outline. Within the total coverage area, each segment 23, 24 defines one or more contact areas 42 that define a total contact area less than the total coverage area. As shown in FIG. 22, the contact areas lie on an engagement plane E. The engagement plane E represents the region of the infeed table that the cast conveyor segments 23, 24 contact and slide along during operation of the infeed conveyor 4. In comparison to one of the welded conveyor chain segments 240 having tangent edges 246, 248, the larger and substantially flat contact area 42 allows for the cast conveyor segments 23, 24 to smoothly slide along the sliding floor reducing wear of the sliding floor. The remaining area or “non-contact area” has a concave shape that curves away from the engagement surface E. The contact areas 42, designated by shading in FIGS. 16 and 19, define a percentage of contact area with respect to the total coverage area. This percentage of contact area is relatively constant throughout the life of the chain 44. The percentage of contactarea in each segment 23, 24, and likewise the percentage of contact area of the chain 44, is relatively large compared to the prior art welded chain described above in the background section. The large contact area percentage contributes to the longevity of the cast chain 44. In some constructions, the total contact area is from 10% to 20% of the total coverage area. In some constructions, the total contact area is from 13% to 18% of the total coverage area. In the example below, the total contact area is 15.5% of the total coverage area.Calculation: percentage of contact area = total contact area of segment / total coverage area of segment

[0061] The percentage of contact area could also be calculated for a gang of chain segments 23, 24. The above percentage ranges may also apply for a gang of chain segments 23, 24. Below is an example of a 10-row gang for calculating percentage of contact area.Calculation: percentage of contact area = (total contact area of gang / total coverage area of the gang) x 100 total contact area of gang = 14.565 in2total contact area per segment * 30 segments per gang = 436.956 in2total coverage area of a gang = 48” length of 10 rows x 58.75 width = 2,820 in2436.956 / 2820 x 100 = 15.5%

[0062] Unless the context of their usage unambiguously indicates otherwise, the articles “a” and “an” should not be interpreted as meaning “one” or “only one.” Rather these articles should be interpreted as meaning “at least one” or “one or more.” Although certain embodiments, examples, features, and aspects have been described and illustrated, variations and modifications exist within the scope and spirit of the subject matter explained and shown.

Claims

CLAIMSWhat is claimed is:

1. A cast conveyor chain segment comprising: a leading edge including at least one hinge pin aperture configured to receive a hinge pin for connecting the cast conveyor chain segment to another like cast conveyor chain segment in a forward longitudinal direction; a trailing edge including at least one hinge pin aperture configured to receive a hinge pin for connecting the cast conveyor chain segment to another like cast conveyor chain segment in a rearward longitudinal direction; and a main body portion extending between the leading edge and the trailing edge, the main body portion having a bottom side including open cavities and webbing extending from the leading edge to the trailing edge, and an upper surface extending from the leading edge to the trailing edge, wherein the cast conveyor chain segment is a monolithic body, cast from a metallic material to include the main body portion, the at least one hinge pin aperture of the leading edge, and the at least one hinge pin aperture of the trailing edge.

2. The cast conveyor chain segment of claim 1, wherein in a bottom view, the cast conveyor chain segment defines a total area, and wherein 10 to 20 percent of the total area occupies a plane at a bottom end of the cast conveyor chain segment to define a total wear surface contact area.

3. The cast conveyor chain segment of claim 1, wherein the cast conveyor chain segment is cast austempered ductile iron.

4. The cast conveyor chain segment of claim 1 , wherein the upper surface of the cast conveyor chain segment is crowned.

5. The cast conveyor chain segment of claim 4, wherein the upper surface is crowned throughout, from the leading edge to the trailing edge, except for one or more outwardly projecting cleats and one or more flat roller guide surfaces, and wherein the one or more flat roller guide surfaces includes a first flat roller guide surface at a first side edge of the cast conveyor chainsegment and a second flat roller guide surface at a second side edge of the cast conveyor chain segment.

6. The cast conveyor chain segment of claim 5, wherein the one or more flat roller guide surfaces includes a third flat roller guide surface at a widthwise center between the first side edge and the second edge.

7. The cast conveyor chain segment of claim 1, wherein the at least one hinge pin aperture of the leading edge includes two hinge pin apertures, and the at least one hinge pin aperture of the trailing edge includes two hinge pin apertures longitudinally aligned with the two hinge pin apertures of the leading edge, the cast conveyor chain segment including a first side edge that connects the leading and trailing edges, a first roll pin aperture adjacent a second side edge that connects the leading and trailing edges, and a second roll pin aperture adjacent the second side edge, wherein the first and second roll pin apertures intersect, respectively, one of the two hinge pin apertures of the leading edge and one of the two hinge pin apertures of the trailing edge.

8. The cast conveyor chain segment of claim 1, wherein the at least one hinge pin aperture of the leading edge includes three hinge pin apertures, and the at least one hinge pin aperture of the trailing edge includes three hinge pin apertures longitudinally aligned with the three hinge pin apertures of the leading edge.

9. The cast conveyor chain segment of claim 1, wherein between the leading and trailing edges, the main body portion of the cast conveyor chain segment has a thickness of less than 0.25 inch measured perpendicular to the upper surface.

10. The cast conveyor chain segment of claim 1, wherein the bottom side includes a plurality of raised sprocket guides.

11. The cast conveyor chain segment of claim 1, wherein each of the at least one hinge pin aperture of the leading edge and each of the at least one hinge pin aperture of the trailing edge has a shape that is elongated longitudinally.

12. A conveyor chain comprising: a plurality of slats indexed in the forward and rearward longitudinal directions, each of the plurality of slats including a plurality of the cast conveyor chain segments of claim 1 arranged in a row, each one of the plurality of slats extending transverse to the forward and rearward longitudinal directions to define a chain width; and between each adjacent pair of slats of the plurality of slats, ajoint including a corresponding hinge pin extending along a hinge pin axis and penetrating both the at least one hinge pin aperture of the leading edge of each cast conveyor chain segment in a first row of the adjacent pair and the at least one hinge pin aperture of the trailing edge of each cast conveyor chain segment in a second row of the adjacent pair, wherein the respective joints connect the plurality of slats together to form a complete loop.

13. The conveyor chain of claim 12, wherein the plurality of cast conveyor chain segments of half of the plurality of slats include two cast end segments having a width equal to one-half a width defined by other ones of the plurality of cast conveyor chain segments.

14. The conveyor chain of claim 12, wherein the plurality of cast conveyor chain segments of each of the plurality of slats include one cast end segment having a width equal to one-half a width defined by other ones of the plurality of cast conveyor chain segments.

15. The conveyor chain of claim 12, wherein the plurality of cast segments includes exactly two types of cast segments: a first segment having a first width, and a second segment having a width one-half of the first width, wherein each of the plurality of slats is constructed using a quantity N of the first segments and exactly one of the second segments, and wherein in sequential ones of the plurality of slats, the one second segment is positioned at opposite widthwise ends.

16. The conveyor chain of claim 12, wherein at each joint, the hinge pin is retained in position along the hinge pin axis while remaining free to rotate relative to the adjacent pair of slats about the hinge pin axis.

17. A horizontal grinder comprising: an infeed system including the conveyor chain of claim 12 and an infeed table supporting an upper run of the conveyor chain; a comminution system positioned adjacent a downstream end of the infeed system; and a discharge conveyor positioned downstream of the comminution system to receive material therefrom.

18. The horizontal grinder of claim 17, wherein the infeed table includes one or more wear plates directly supporting the upper run of the conveyor chain, and 10 to 20 percent of the area of the conveyor chain facing the infeed table is configured to establish contact with the one or more wear plates of the infeed table.

19. The horizontal grinder of claim 17, further including a drive pulley with a plurality of sprockets engaged with a plurality of raised sprocket guides on the bottom sides of the plurality of cast segments on an interior of the conveyor chain loop, wherein the drive pulley extends the full chain width.

20. The horizontal grinder of claim 19, wherein each sprocket tooth is contacted both in the longitudinal direction and transverse thereto by the plurality of raised sprocket guides.

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