DIPPER HANDLE FOR ELECTRIC ROPE SHOVEL

Abstract

In an electric rope shovel, the dipper handle must support significant weight, which presents the potential of fatigue cracking at interfaces between sections of the dipper handle. Accordingly, embodiments of a dipper handle are disclosed that reduce stress at the interface between the tube section and the intermediate section, to which the crowd control is coupled. In particular, spacing is provided between the interface and the crowd bores, to separate the interface from the stiffness of the coupling. In addition, the walls of the dipper handle may be thickened, proximate the interface, with beveled edges at the interface, to provide a stronger, more durable, weld.

Claims

1. An intermediate section for a dipper handle, the intermediate section comprising: an open first end; an interior cavity extending, along a longitudinal axis, into the intermediate section from the first end; and a pair of crowd bores extending, along a lateral axis that is orthogonal to the longitudinal axis, through respective ones of opposing sides of the intermediate section, into the interior cavity, wherein the pair of crowd bores are aligned with each other along the lateral axis; wherein a first longitudinal distance from the first end to a center of each of the pair of crowd bores is at least 50% of an outer diameter of the intermediate section at the first end.

2. The intermediate section of claim 1, wherein the first longitudinal distance is within 50-80% of the outer diameter.

3. The intermediate section of claim 1, wherein the first longitudinal distance is within 60-70% of the outer diameter.

4. The intermediate section of claim 1, wherein the first longitudinal distance is within 62-64% of the outer diameter.

5. The intermediate section of claim 1, wherein the intermediate section further comprises a pair of bosses on respective ones of the opposing sides of the intermediate section, wherein each of the pair of bosses encircles a respective one of the pair of crowd bores.

6. The intermediate section of claim 5, wherein the intermediate section further comprises a fillet around each of the pair of bosses.

7. The intermediate section of claim 6, wherein a second longitudinal distance from the first end to a closest point of each fillet is at least 10% of the outer diameter.

8. The intermediate section of claim 6, wherein a second longitudinal distance from the first end to a closest point of each fillet is within 15-35% of the outer diameter.

9. The intermediate section of claim 6, wherein a second longitudinal distance from the first end to a closest point of each fillet is within 20-30% of the outer diameter.

10. The intermediate section of claim 6, wherein a second longitudinal distance from the first end to a closest point of each fillet is within 25-27% of the outer diameter.

11. The intermediate section of claim 6, wherein a second longitudinal distance from the first end to a closest point of each fillet is at least 10% of the first longitudinal distance.

12. The intermediate section of claim 6, wherein a second longitudinal distance from the first end to a closest point of each fillet is within 30-60% of the first longitudinal distance.

13. The intermediate section of claim 6, wherein a second longitudinal distance from the first end to a closest point of each fillet is within 25-27% of the first longitudinal distance.

14. The intermediate section of claim 1, further comprising a second end, opposite the first end along the longitudinal axis, wherein a thickness of a wall of the intermediate section, defining the interior cavity, decreases from the first end towards the second end.

15. The intermediate section of claim 1, further comprising a second end, opposite the first end along the longitudinal axis, wherein the first end has a circular cross-sectional profile, wherein the second end has a rectangular cross-sectional profile, and wherein the intermediate section transitions from the circular cross-sectional profile to the rectangular cross-sectional profile along the longitudinal axis.

16. The intermediate section of claim 14, wherein the second end comprises an opening that extends into the interior cavity along the longitudinal axis.

17. A dipper handle comprising: a tube section that is joined to the first end of the intermediate section; the intermediate section of claim 1, wherein the intermediate section further comprises a second end, opposite the first end along the longitudinal axis; and an engagement section that is joined to the second end of the intermediate section, wherein the engagement section is configured to be joined to a dipper.

18. An electric rope shovel comprising: one or more ground-engaging members; a turntable connected to the one or more ground-engaging members; a main body comprising a chassis that is mounted on the turntable; a boom extending from the main body; the dipper handle of claim 17; a crowd control, secured to the boom via a saddle block and secured to the dipper handle via the intermediate section, wherein the crowd control is configured to extend and retract the dipper handle, relative to the boom; and a dipper secured to the engagement section of the dipper handle.

19. A dipper handle comprising: a hollow tube section having a first end and a second end along a longitudinal axis, wherein a wall of the tube section has a uniform first thickness from the first end to a first point that is a first distance from the second end, transitions to a second thickness from the first point to a second point that is a second distance from the second end, and has the second thickness from the second point to an edge of the second end, wherein the edge of the second end is beveled; an intermediate section that includes an open third end that is joined to the second end of the tube section, wherein the third end has a first cross-sectional profile, a fourth end that is opposite the third end along the longitudinal axis, wherein the fourth end has a second cross-sectional profile that is different from the first cross-sectional profile, wherein the intermediate section transitions from the first cross-sectional profile to the second cross-sectional profile along the longitudinal axis, a wall that extends from an edge of the third end to the fourth end, wherein the edge of the third end is beveled, wherein the wall of the intermediate section has the second thickness at the third end, and wherein a thickness of the wall of the intermediate section gradually decreases from the third end towards the fourth end, an interior cavity defined by the wall of the intermediate section, a pair of crowd bores extending, along a lateral axis that is orthogonal to the longitudinal axis, through respective ones of opposing sides of the intermediate section, into the interior cavity, wherein the pair of crowd bores are aligned with each other along the lateral axis, wherein a longitudinal distance from the third end to a center of each of the pair of crowd bores is at least 50% of an outer diameter of the intermediate section at the third end, wherein the beveled edge of the second end of the tube section and the beveled edge of the third end of the intermediate section form a groove, and wherein the tube section and the intermediate section are welded together via the groove; and an engagement section that is joined to the fourth end of the intermediate section, wherein the engagement section is configured to be secured to a dipper.

20. A machine comprising: a dipper handle comprising a tube section having an open first end and an open second end along a longitudinal axis, wherein the tube section has a hollow interior from the first end to the second end, an intermediate section that includes an open third end that is joined to the second end of the tube section, an interior cavity extending, along the longitudinal axis, from the third end to an opposing fourth end of the intermediate section, and a pair of crowd bores extending, along a lateral axis that is orthogonal to the longitudinal axis, through respective ones of opposing sides of the intermediate section, into the interior cavity, wherein the pair of crowd bores are aligned with each other along the lateral axis, wherein a longitudinal distance from the third end to a center of each of the pair of crowd bores is at least 50% of an outer diameter of the intermediate section at the third end, and an engagement section that is joined to the fourth end of the intermediate section, wherein the engagement section is configured to be secured to a dipper; and a crowd control comprising a cylindrical housing and a piston configured to retract into and extend out from the cylindrical housing, wherein the cylindrical housing is at least partially housed within the hollow interior of the tube section, such that, when the piston is fully retracted into the cylindrical housing, a terminal portion of the piston extends through an interface between the second end of the tube section and the third end of the intermediate section, and wherein a terminal end of the piston is secured to the intermediate section via the pair of crowd bores.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The details of embodiments of the present disclosure, both as to their structure and operation, may be gleaned in part by study of the accompanying drawings, in which like reference numerals refer to like parts, and in which:

[0009] FIG. 1 is a side view of a machine that comprises a dipper handle, according to an embodiment;

[0010] FIG. 2 is a perspective view of the dipper handle, according to an embodiment;

[0011] FIG. 3 is a cross-sectional view of the interface between the tube section and intermediate section of the dipper handle, according to an embodiment;

[0012] FIG. 4 is a perspective view of the intermediate section of the dipper handle in isolation, according to an embodiment; and

[0013] FIG. 5 is a cross-sectional view of the intermediate section in isolation, according to an embodiment.

DETAILED DESCRIPTION

[0014] The detailed description set forth below, in connection with the accompanying drawings, is intended as a description of various embodiments, and is not intended to represent the only embodiments in which the disclosure may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of the embodiments. However, it will be apparent to those skilled in the art that embodiments of the invention can be practiced without these specific details.

[0015] In some instances, well-known structures and components are shown in simplified form for brevity of description. For clarity and ease of explanation, some surfaces and details may be omitted in the present description and figures. It should also be understood that the various components illustrated herein are not necessarily drawn to scale. In other words, the features disclosed in various embodiments may be implemented using different relative dimensions within and between components than those illustrated in the drawings.

[0016] As used herein, the terms side, top, bottom, front, rear, above, below, topside,, underside, and the like are used for convenience of understanding to convey the relative positions of various components with respect to each other, and do not imply any specific orientation of those components in absolute terms (e.g., with respect to the external environment or the ground). In addition, the terms respective and respectively signify an association between members of a group of first components and members of a group of second components. For example, the phrase each component A connected to a respective component B would signify A1 connected to B1, A2 connected to B2, . . . and AN connected to BN. Furthermore, a reference numeral with an appended letter will be used to refer to a specific component, whereas the same reference numeral without any appended letter will be used to refer collectively to a plurality of the component or to refer to a generic or arbitrary instance of the component.

[0017] FIG. 1 is a side view of a machine 100 that comprises a dipper handle 200, according to an embodiment. Machine 100 is illustrated as an electric rope shovel (ERS). Examples of electric rope shovels include Models 7295, 7395, and 7495 of electric rope shovels, offered by Caterpillar Inc. of Peoria, Illinois, as well as models of electric rope shovels offered by other manufacturers. However, it should be understood that machine 100 may be any type of machine that utilizes a dipper handle 200, including other types of shovels, and machines that utilize a dipper handle 200 for other types of work implements.

[0018] Machine 100 may comprise a main body 110. Main body 110 may comprise a cabin 112 that houses one or more controls for machine 100 and is configured to accommodate one or more local operators. Operators within cabin 112 may utilize the control(s) to operate machine 100, including propelling machine 100, relative to the ground, and moving or otherwise operating one or more work implements or other components of machine 100 (e.g., hoisting, crowding, swinging, etc.). Additionally or alternatively, machine 100 may be remotely operated and/or capable of autonomous or semi-autonomous operation. In these cases, cabin 112 could potentially be omitted.

[0019] Main body 110 may comprise a chassis that is mounted on a turntable 120 that is connected to and/or supported by one or more ground-engaging members 130. Turntable 120 is configured to rotate main body 110 relative to ground-engaging members 130. For example, turntable 120 may enable main body 110 to rotate 360 degrees, relative to ground engaging members 130. Alternatively, turntable 120 may constrain the rotation of main body 110, relative to ground-engaging members, to a range of less than 360 degrees (e.g., 270 degrees, 180 degrees, etc.).

[0020] Ground-engaging members 130 are illustrated as tracks, but may comprise any movement system that is capable of moving relative to the ground, such as two or more axles of wheels with tires. It should be understood that, in the case that ground-engaging members 130 comprise tracks, there may be a pair of tracks on either side of machine 100. Similarly, in the case that ground-engaging members 130 are wheels, there may be at least two wheels on either side of machine 100.

[0021] In the case that machine 100 is an electric rope shovel, the work implement of machine 100 may comprise a boom 140, a frame 150, a crowd control 160, a dipper 170, and a dipper handle 200. Boom 140 is secured on a first end to the front end of main body 110, and extends upwards and away from main body 110, such that a second end of boom 140 is positioned forward of cabin 112 and higher than cabin 112.

[0022] Frame 150, which is illustrated as an A-frame, may be secured to main body 110, so as to extend vertically above main body 110. A cable 152 may be secured on a first end to frame 150, looped through one or more apertures on the second end of boom 140, and then secured on a second end to frame 150, such that cable 152 at least partially supports the second end of boom 140 against the weight of boom 140. In an alternative embodiment, a different mechanism may be used to support boom 140.

[0023] A saddle block 142 may be secured to boom 140, at a position (e.g., approximately midway) between the first and second ends of boom 140. Saddle block 142 may be configured to pivot, relative to boom 140, around a normal axis that is normal to the plane of perspective in FIG. 1. Saddle block 142 may pivot by virtue of a yoke or other mechanism. Saddle block 142 is configured to slidably receive dipper handle 200, and may comprise additional support structures and/or features for supporting dipper handle 200.

[0024] A crowd control 160 may be secured through saddle block 142. Crowd control 160 may be hydraulically driven. In this case, crowd control 160 may comprise a double-acting hydraulic actuator that includes a cylindrical housing, which is fixed through saddle block 142, and a piston that is moveable relative to the cylindrical housing. The piston may retract into the cylindrical housing and extend out of the cylindrical housing, according to the hydraulic pressure that is applied to the piston within the cylindrical housing.

[0025] The piston of crowd control 160 may be fixed to dipper handle 200, as will be discussed elsewhere herein. Thus, dipper handle 200 will move with piston, relative to the cylindrical housing of crowd control 160 and saddle block 142 to which the cylindrical housing is secured. In particular, when the piston retracts into the cylindrical housing, dipper handle 200 will retract towards saddle block 142, and when the piston extends out from the cylindrical housing, dipper handle 200 will extend away from saddle block 142.

[0026] In an alternative embodiment, crowd control 160 may comprise a different mechanism for moving dipper handle 200, such as a rack-and-pinion mechanism or rope crowd mechanism. A rope crowd mechanism may comprise a crowd drum, crowd rope, and retract rope. The crowd rope may be secured to a first end of dipper handle 200, farthest from dipper 170, extend over one or more sheaves near the middle of dipper handle 200, and terminate at the crowd drum. The retract rope may be secured to a second end of dipper handle 200, closest to dipper 170, extend over one or more sheaves, and terminate at the crowd drum. Rotation of the crowd drum in a first direction will cause dipper handle 200 to extend, and rotation of the crowd drum in a second direction, opposite the first direction, will cause dipper handle 200 to retract.

[0027] Dipper handle 200 is secured, on the end that is opposite crowd control 160, to dipper 170. For ease of understanding, opening 171 of dipper 170 will be referred to as being positioned on the top of dipper 170, despite being illustrated as being substantially orthogonal to the ground. The top rear end of dipper 170, near the rear end of opening 171, may comprise a first mounting structure 172 that is directly secured to dipper handle 200. First mounting structure 172 may comprise a pair of apertures that are aligned with each other along the normal axis and which align with corresponding apertures in dipper handle 200 along the normal axis. Thus, first mounting structure 172 may be directly secured to dipper handle 200 by fixing a pin or other fastening mechanism through the aligned apertures of first mounting structure 172 and dipper handle 200. The pin enables dipper 170 to pivot, within a range of angles, relative to dipper handle 200. In an alternative embodiment, another mechanism may be used to secure dipper 170 to dipper handle 200.

[0028] The bottom rear end of dipper 170, near the rear end of bottom 178, may comprise a second mounting structure 174 that is indirectly secured to dipper handle 200. Second mounting structure 174 may comprise a pair of apertures that are aligned with each other along the normal axis and which align with corresponding apertures in a linkage 180 along the normal axis. Thus, second mounting structure 174 may be secured to linkage 180 by fixing a pin or other fastening mechanism through the aligned apertures of second mounting structure 174 and linkage 180. Similarly, linkage 180 may comprise a pair of apertures that are aligned with each other along the normal axis and which align with corresponding apertures in dipper handle 200 along the normal axis. Thus, linkage 180 may be directly secured to dipper handle 200 by fixing a pin through the aligned apertures of linkage 180 and dipper handle 200. The pin enables linkage 180 to pivot, within a range of angles, relative to dipper handle 200. Linkage 180 controls the rotation of dipper 170, relative to dipper handle 200. In an alternative embodiment, another mechanism may be used to indirectly or directly secure dipper 170 to dipper handle 200.

[0029] Dipper 170, which may also be referred to as a bucket, is configured to shovel materials through opening 171, for example, during a mining operation. A top front edge of dipper 170 may comprise teeth 176 and/or other features that facilitate digging and scooping of the materials into opening 171. Dipper 170 may also comprise a hinged bottom 178 that is pivotable with respect to the body of dipper 170. Bottom 178 may be pivoted to an open position to dump material from dipper 170 and pivoted to a closed position when loading dipper 170 with material.

[0030] Machine 100 may comprise a first sheave 192 that is secured to the second end of boom 140, and a second sheave 194 that is secured to the top rear edge of dipper 170, in front of and spaced apart from first mounting structure 172. One end of a hoist cable 196 may be fixed to a hoist drum or winch on main body 110. The other end of hoist cable 196 may be wound around first sheave 192, around second sheave 194, and fixed to boom 140 near first sheave 192. Thus, hoist cable 196 may be retracted to raise the front of dipper 170, and extended to lower the front of dipper 170. This movement of dipper 170 is in addition to the extension and retraction of dipper 170 via the operation of crowd control 160, by virtue of the connection between crowd control 160 and dipper handle 200.

[0031] Although not illustrated, machine 100 may comprise a number of additional components to facilitate operations of machine 100, including the operation of dipper 170. For example, machine 100 may comprise an internal combustion engine (e.g., powered by diesel gasoline or other fuel) or an electric motor (e.g., powered by a battery pack) that is configured to drive ground-engaging members 130. Machine 100 may also comprise one or more electronic control modules (ECMs) that collect data (e.g., from one or more sensors), process the data, and output control commands to one or more controllable components (e.g., turntable 120 for swinging, crowd control 160 for crowding, the hoist drum for hoist cable 196 for hoisting, bottom 178 of dipper 170 for dumping, etc.) of machine 100, based on the processing of the data.

[0032] FIG. 2 is a perspective view of dipper handle 200, with an inset close-up view of a portion of dipper handle 200, according to an embodiment. Dipper handle 200 may comprise a tube section 210, an intermediate section 220, and an engagement section 230. Each of tube section 210, intermediate section 220, and/or engagement section 230 may be cast from steel, alloys, and/or the like. It should be understood that, in alternative embodiments, there may be fewer or more sections in dipper handle 200. The interface between tube section 210 and intermediate section 220 is of particular relevance to disclosed embodiments.

[0033] Tube section 210 comprises an elongate structure that extends, along a longitudinal axis L, from a first end E1, which is configured to interface with crowd control 160, to a second end E2, which interfaces with intermediate section 220. First end E1 of tube section 210 may be open and configured to receive an end of crowd control 160. For example, in an embodiment in which crowd control 160 comprises a hydraulic actuator, at least a portion of the cylindrical housing, including the internal piston of the hydraulic actuator, may extend through first end E1 into the interior of tube section 210, along longitudinal axis L. In this case, the terminal end of the piston, which is capable of retracting into and extending out of the cylindrical housing, may be secured to intermediate section 220, via crowd bores 223, as will be described elsewhere herein. Thus, crowd control 160 may be secured to dipper handle 200 via intermediate section 220, through tube section 210.

[0034] Tube section 210 is illustrated as a cylinder, with a uniform, circular cross-sectional profile. However, it should be understood that tube section 210 may have any different cross-sectional profile (e.g., rectangular, triangular, etc.), as long as the cross-sectional profile is capable of accommodating the cross-sectional profile of the portion of crowd control 160 that is housed within tube section 210. Thus, the term tube or tubular should be understood to refer to the fact that tube section 210 may be hollow from first end E1 to second end E2, rather than to any particular cross-sectional profile. In any case, the outer profile of tube section 210 may be configured to slide relative to saddle block 142, during extension and retraction of dipper handle 200 via crowd control 160.

[0035] Intermediate section 220 extends, along longitudinal axis L, from an open first end E3 (which may also be referred to herein as the third end), which interfaces with second end E2 of tube section 210, to a second end E4 (which may also be referred to herein as the fourth end), which interfaces with engagement section 230. In other words, second end E2 of tube section 210 is joined to first end E3 of intermediate section 220. Intermediate section 220 may comprise a pair of bosses 222 that each encircles a respective crowd bore 223, to provide increased strength around crowd bores 223 and facilitate coupling of intermediate section 220 to crowd control 160. Bosses 222 and respective crowd bores 223 are positioned on opposing side of intermediate section 220, which is hollow, so as to face each other, such that crowd bores 223 are aligned along a lateral axis R that is orthogonal to longitudinal axis L and corresponds to the normal axis in FIG. 1. Accordingly, a pin or other fastening mechanism may be inserted, along lateral axis L, through both crowd bores 223, as well as a corresponding aperture through the end of the piston of crowd control 160, to thereby secure the piston to intermediate section 220.

[0036] Engagement section 230 extends, along longitudinal axis L, from a first end E5 (which may also be referred to herein as the fifth end), which interfaces with second end E4 of intermediate section 220, to a second end E6 (which may also be referred to herein as the sixth end), which engages with dipper 170. In other words, first end E5 of engagement section 230 is joined to second end E4 of intermediate section 230, and second end E6 of engagement section 230 is joined to dipper 170. In the illustrated embodiment, engagement section 230 comprises a pair of engagement fingers 232 that are spaced apart from each other along lateral axis R. Each engagement finger 232 may comprise a respective aperture 233. For example, engagement finger 232A comprises aperture 233A, and engagement finger 232B comprises aperture 233B. Apertures 233 are positioned so as to face each other, such that apertures 233 are aligned along lateral axis R. Fingers 232 are configured to engage with first mounting structure 172. In particular, a pair of apertures within first mounting structure 172 may align with apertures 233 along lateral axis R. Thus, first mounting structure 172 may be directly secured to engagement section 230 by fixing a pin or other fastening mechanism through the apertures of first mounting structure 172, with apertures 233 aligned therebetween, to thereby directly secure dipper handle 200 to dipper 170.

[0037] The underside of engagement section 230 may comprise a pair of engagement structures 234 that are spaced apart from each other along lateral axis R. Each engagement structure 234 may comprise a respective aperture 235. For example, engagement structure 234A comprises aperture 235A, and engagement structure 234B comprises aperture 235B. Apertures 235 are positioned so as to face each other, such that apertures 235 are aligned along lateral axis R. Engagement structures 234 are configured to engage with linkage 180. In particular, a pair of apertures within linkage 180 may align with apertures 235 along lateral axis R. Thus, linkage 180 may be directly secured to engagement section 230 by fixing a pin or other fastening mechanism through the apertures of linkage 180, with apertures 235 aligned therebetween. As discussed elsewhere herein, an opposing end of linkage 180 may be secured to second mounting structure 174 of dipper 170, to thereby indirectly secure dipper handle 200 to dipper 170.

[0038] Intermediate section 220 may have a first cross-sectional profile at first end E3 and a second cross-sectional profile at second end E4 that differs from the first cross-sectional profile. For instance, the first cross-sectional profile may be circular, and the second cross-sectional profile may be rectangular. The first cross-sectional profile and outer dimensions of intermediate section 220 at first end E3 match the cross-sectional profile and outer dimensions of tube section 210 at second end E2, such that the outer surfaces are generally continuous after being joined (e.g., welded) together. Similarly, the second cross-sectional profile and outer dimensions of intermediate section 220 at second end E3 match the cross-sectional profile and outer dimensions of engagement section 230 at first end E5 of engagement section 230, such that the outer surfaces are generally continuous after being joined (e.g., welded) together. Thus, the outer profile of intermediate section 220 is contoured (e.g., via casting) to transition from the cross-sectional profile of second end E2 of tube section 210 to the cross-sectional profile of first end E5 of engagement section 230. As a result, the entire dipper handle 200 has a generally continuous outer surface, despite being fabricated as different sections.

[0039] FIG. 3 is a cross-sectional view of the interface between tube section 210 and intermediate section 220 of dipper handle 200, cut along line A-A in FIG. 2, with an inset close-up view of the interface, according to an embodiment. A portion of crowd control 160 is visible in a retracted or nearly retracted position within the main view, but is omitted from the inset close-up view.

[0040] The illustrated portion of crowd control 160 comprises a cylindrical housing 162 that houses a piston 164. Cylindrical housing 162 has an outer diameter that matches (e.g., equal to or slightly less than) the inner diameter of tube section 210, such that cylindrical housing 162 and tube section 210 can slide relative to each other. Crowd control 160 may also comprise a bushing 166 at the open, terminal end of cylindrical housing 162 to facilitate sliding of tube section 210, relative to cylindrical housing 162.

[0041] The terminal end of piston 164 is secured to intermediate section 220. In particular, the terminal end of piston 164 comprises an engagement structure 165 that comprises an aperture oriented along lateral axis R (i.e., the normal axis in FIG. 3). This aperture is configured to align, along lateral axis R, within the hollow interior cavity of intermediate section 220, with the pair of crowd bores 223, through the sides of intermediate section 220. A pin 310 or other fastening mechanism may be inserted and secured through the pair of crowd bores 223 with the aperture of engagement structure 165 aligned therebetween, to thereby secure piston 164 to intermediate section 220.

[0042] During operation of crowd control 160, cylindrical housing 162 remains substantially stationary. Thus, piston 164 may extend, along longitudinal axis L, to thereby cause dipper handle 200, including tube section 210, intermediate section 220, and engagement section 230, by virtue of the connection between piston 164 and intermediate section 220, to slide in a direction away from cylindrical housing 162. It should be understood that this extension of piston 164, and thereby the extension of dipper handle 200, causes dipper 170 to move away from crowd control 160. Conversely, piston 164 may retract, along longitudinal axis L, to thereby cause dipper handle 200, including tube section, 210, intermediate section 220, and engagement section 230, by virtue of the connection between piston 164 and intermediate section 220, to slide in a direction towards cylindrical housing 162. It should be understood that this retraction of piston 164, and thereby the retraction of dipper handle 200, causes dipper 170 to move towards crowd control 160.

[0043] In an embodiment, the edge of second end E2 of tube section 210 and the edge of first end E3 of intermediate section 220 are both beveled, to form a V-shaped groove 320 around the outer circumference of dipper handle 200. Groove 320 may form a sector S of an imaginary circle. Sector S may be in the range of 30 to 90 degrees, preferably in the range of 50 to 70 degrees, and more preferably approximately 60 degrees. As used herein, the term approximately should be understood to mean plus or minus (+/) five (5) of the relevant units (e.g., degrees in this case), unless otherwise stated. Groove 320 facilitates welding of tube section 210 to intermediate section 220. In particular, a welding material 325 may be welded within groove 320, from the exterior of dipper handle 200, to thereby secure intermediate section 220 to tube section 210.

[0044] As illustrated, the outer diameter D1 at second end E2 of tube section 210 and first end E3 of intermediate section 220 may be identical, such that the interface between tube section 210 and intermediate section 220 has a uniform outer diameter D1 when welded together. In addition, the inner diameters D2 at second end E2 of tube section 210 and first end E3 of intermediate section 220 may be identical, such that the interface between tube section 210 and intermediate section 220 has a uniform inner diameter D2 as well. In other words, the walls of dipper handle 200 may have a uniform thickness across the interface.

[0045] The inner diameter of each of tube section 210 and/or intermediate section 220 may be contoured so as to decrease approaching the interface. In other words, the thickness of the wall of each of tube section 210 and/or intermediate section 220 may increase approaching the interface. It should be understood that the thickness of the wall of tube section 210 is defined by the distance between an outer surface 214 of tube section 210, which defines the outer diameter D1 of tube section 210, and an inner surface 215 of tube section 210, which defines the inner diameter D2 of tube section 210. Similarly, the thickness of the wall of intermediate section 220 is defined by the distance between an outer surface 224 of intermediate section 220, which defines the outer diameter D1 of intermediate section 220, and an inner surface 225 of intermediate section 220, which defines the inner diameter D2 of intermediate section 220.

[0046] The thickness of the wall of tube section 210 may have a uniform first thickness T1 from first end E1 up to a first point that is a first distance from the interface with intermediate section 220 on second end E2, gradually increase, in a linear or curved transition, to a second thickness T2 from the first point to a second point that is a second distance from the interface, which is less than the first distance, and have uniform second thickness T2 uniformly from the second point up to the beveled edge of tube section 210 on second end E2. It should be understood that first thickness T1 is less than second thickness T2. In an embodiment, the vast majority of the length of tube section 210, along longitudinal axis L, has the uniform first thickness T1. For instance, the first 90-95% of the entire longitudinal length of tube section 210, from first end E1 to second end E2, may have the uniform first thickness T1, while the transition and the portion of tube section 210 having second thickness T2 represent only 5-10% of the longitudinal length of tube section 210. As one specific example, the entire longitudinal length of tube section 210 may be 9 meters, and a continuous 8.5 meters of tube section 210, starting from first end E1 and ending at the start of the transition to second thickness T2, may have first thickness T1. Continuing this specific example, the transition may be 0.2 meters in length, and thickness T2 may span the remaining 0.3 meters. It should be understood that the length of tube section 210 having the first thickness T1 should be sufficient to accommodate the desired stroke of crowd control 160.

[0047] Additionally or alternatively, the thickness of the wall of intermediate section 220 may start with second thickness T2 from the beveled edge on first end E3 of intermediate section 220. Immediately or starting from a first distance from the interface with tube section 210, the thickness of the wall may gradually decrease, in a linear or curved transition, to a third thickness T3 at a second distance from the interface, which is greater than the first distance. It should be understood that third thickness T3 is less than second thickness T2. Third thickness T3 may be identical, similar, or different from first thickness T1.

[0048] Width W1, which may also be referred to herein as a longitudinal distance, represents a distance between the edge of first end E3 of intermediate section 220 and the center of crowd bore 223, whereas width W2, which may also be referred to herein as a longitudinal distance, represents a distance between the edge of first end E3 of intermediate section 220 and the closest point of a radius or fillet 221 around boss 222 that encircles crowd bore 223. In the embodiments of the intermediate member that are disclosed in the '563 patent, width W2 is substantially zero or near zero. In other words, the fillet starts right at or near the edge of the intermediate member. In contrast, present embodiments space fillet 221 away from the edge of first end E3 of intermediate section 220, along longitudinal axis L, by width W2. It should be understood that the addition of width W2 increases width W1, relative to embodiments of the intermediate member in the '563 patent, by the value of width W2.

[0049] Exemplary values for various dimensions and ratios of the interface between tube section 210 and intermediate section 220 will now be provided. It should be understood that these values and ratios are merely examples, and that the precise dimensions and ratios will depend on the dimensions of crowd control 160, dipper 170, dipper handle 200, and/or other components of machine 100, the design goals and requirements of machine 100, and/or other factors.

[0050] In an embodiment, second thickness T2 is greater than first thickness T1 and/or third thickness T3 by 10-40%, more preferably by 20-30%, and, in a particular embodiment, by 24-26% (e.g., 25%). As an example, second thickness T2 may be in the range of 85-95 millimeters, while first thickness T1 and third thickness T3 may be in the range of 70-80 millimeters. In a particular implementation, second thickness T2 was approximately 91-92 millimeters, while first thickness T1 and third thickness T3 were approximately 73-74 millimeters.

[0051] In an embodiment, width W1 has a value that is at least 50% of outer diameter D1, is preferably within 50-80% of outer diameter D1, is more preferably within 60-70% of outer diameter D1, and, in a particular embodiment, is within 62-64% (e.g., approximately 63%) of outer diameter D1. As an example, width W1 may be in the range of 500-600 millimeters, while outer diameter D1 may be in the range of 825-925 millimeters. In a particular implementation, width W1 was approximately 550 millimeters, while outer diameter D1 was approximately 875 millimeters.

[0052] In an embodiment, width W2 has a value that is at least 10% of outer diameter D1, is preferably within 15-35% of outer diameter D1, is more preferably within 20-30% of outer diameter D1, and, in a particular embodiment, is within 25-27% (e.g., approximately 26%) of outer diameter D1. As an example, width W2 may be in the range of 200-250 millimeters, while outer diameter D1 may be in the range of 825-925 millimeters. In a particular implementation, width W2 was approximately 225 millimeters, while outer diameter D1 was approximately 875 millimeters.

[0053] In an embodiment, width W2 has a value that is at least 10% of width W1, is preferably within 30-60% of width W1, is more preferably within 40-50% of width W1, and, in a particular embodiment, is within 40-42% (e.g., 41%) of width W1. As an example, width W2 may be in the range of 200-250 millimeters, while width W1 may be in the range of 500-600 millimeters. In a particular implementation, width W2 was approximately 225 millimeters, while width W2 was approximately 550 millimeters.

[0054] FIG. 4 is a perspective view of intermediate section 220 of dipper handle 200 in isolation, according to an embodiment. In this view, both bosses 222A and 222B, and one crowd bore 223A through boss 222A, are visible. In addition, fillet 221A, around boss 222, is visible. Each fillet 221 may provide a smooth transition between the side surface of intermediate section 220 and a respective boss 222.

[0055] As illustrated, intermediate section 220 may have a generally circular cross-sectional profile on first end E3 to facilitate the connection to tube section 210, and a generally rectangular cross-sectional profile on second end E4 to facilitate the connection to engagement section 230. On the surface of second end E4 that is orthogonal to longitudinal axis L, intermediate section 220 may comprise an opening 226, which connects the interior cavity of intermediate section 220 with an interior cavity of engagement section 230. Thus, the entire dipper handle 200 may comprise a contiguous interior cavity from first end E1 of tube section 210, through intermediate section 220, to second end E6 of engagement section 230. This enables crowd control 160 to be inserted through the interior of dipper handle 200, as well as reduces the overall weight of dipper handle 200.

[0056] FIG. 5 is a cross-sectional view of intermediate section 220 in isolation, cut along axis B-B in FIG. 4, according to an embodiment. In this view, it can be seen that intermediate section 220 comprises an interior cavity 228 that extends, along longitudinal axis L, into intermediate section 220 from first end E3 to second end E4 and through opening 226. A pair of crowd bores 223 extend, along lateral axis R, through respective ones of opposing sides of intermediate section 220, into interior cavity 228, so as to be aligned with each other along lateral axis R. In addition, intermediate section 220 comprises a pair of bosses 222 on respective ones of the opposing sides of intermediate section 220, such that each boss 222 encircles a respective crowd bore 223. Intermediate section 220 may also comprise a fillet 221 around each of the pair of bosses 222.

[0057] In addition, the thickness of the wall of intermediate section 220, defining interior cavity 228, may decrease from first end E3 to second end E4. The thickness of the wall may decrease along the entire longitudinal length of intermediate section 220. In other words, the inner diameter, defined by inner surface 225 of intermediate section 220, may gradually increase, in a linear or curved transition, from first end E3 to second end E4, while the outer diameter, defined by outer surface 224 of intermediate section 220, may be uniform and constant. In an alternative embodiment, the thickness of the wall may decrease, from first end E3 to second end E4, along only a portion of the longitudinal length of intermediate section 220.

INDUSTRIAL APPLICABILITY

[0058] In an electric rope shovel, the dipper handle must support its own weight and the weight of a loaded dipper at positions off the ground. This presents the potential of fatigue cracking at interfaces between sections of the dipper handle. In particular, such cracking may occur at the interface between the tube section and intermediate section of the dipper handle.

[0059] Accordingly, embodiments of dipper handle 200 reduce stress at the interface between tube section 210 and intermediate section 220, by separating the interface from the stiffness of the crowd hub formed by crowd bores 223. In particular, a width W1 (i.e., first longitudinal distance) from first end E3 of intermediate section 220 to a center of each crowd bore 223 may be at least 50% (e.g., 50-80%, 60-70%, 62-64%, etc.) of outer diameter D1 of intermediate section 220 at first end E3 of intermediate section 220. Additionally or alternatively, a width W2 (i.e., second longitudinal distance) from first end E3 of intermediate section 220 to the closest point of fillet 221 may be at least 10% (e.g., 15-35%, 20-30%, 25-27%, etc.) of outer diameter D1 of intermediate section 220 at first end E3 of intermediate section 220. Additionally or alternatively, width W2 may be at least 10% (e.g., 30-60%, 20-30%, 25-27%, etc.) of width W1. In testing, disclosed embodiments have demonstrated a greater than 6% increase in weld life at the toe of the weld and a greater than 5% increase in weld life at the root of the weld, relative to the same interface in the '563 patent, thereby reducing downtime and increasing productivity of the overall machine 100.

[0060] In addition, as a result of the contoured inner surfaces 215 and 225 of tube section 210 and intermediate section 220, respectively, the walls of tube section 210 and intermediate section 220 are thicker at the interface between tube section 210 and intermediate section 220. This provides enhanced strength and rigidity at the interface. It also increases the depth of groove 320 to T2, as opposed to T1, which provides a greater weld depth for welding material 325 and thereby increases the strength of the weld. In testing, disclosed embodiments have demonstrated a greater than 55% increase in weld life at the toe of the weld and a greater than 90% increase in weld life at the root of the weld, relative to a baseline without contoured inner surfaces, thereby reducing downtime and increasing productivity of the overall machine 100.

[0061] Furthermore, the use of beveled edges to form groove 320 may obviate the need to create a weld on inner surfaces 215 and 225 of tube section 210 and intermediate section 220, respectively. This facilitates joinder of tube section 210 and intermediate section 220, and reduces the cost and complexity of manufacturing dipper handle 200, without impacting the performance of dipper handle 200.

[0062] It will be understood that the benefits and advantages described above may relate to one embodiment or may relate to several embodiments. Aspects described in connection with one embodiment are intended to be able to be used with the other embodiments. Any explanation in connection with one embodiment applies to similar features of the other embodiments, and elements of multiple embodiments can be combined to form other embodiments. The embodiments are not limited to those that solve any or all of the stated problems or those that have any or all of the stated benefits and advantages.

[0063] The preceding detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. The described embodiments are not limited to usage in conjunction with a particular type of machine. Hence, although the present embodiments are, for convenience of explanation, depicted and described as being implemented in a electric rope shovel, it will be appreciated that it can be implemented in various other types of shovels and machines with dipper handles, and in various other systems and environments. Furthermore, there is no intention to be bound by any theory presented in any preceding section. It is also understood that the illustrations may include exaggerated dimensions and graphical representation to better illustrate the referenced items shown, and are not considered limiting unless expressly stated as such.