Dipper Assembly And Parts Thereof

Abstract

The present invention concerns a dipper assembly and parts thereof for use with a mining shovel. The dipper assembly includes: a dipper body having a back wall and an open dipper bottom; a dipper door pivotally coupled to the back wall of the dipper body and moveable between open and closed positions relative to the open dipper bottom; and a latch assembly for releasably securing the door in the closed position. The latch assembly includes a latch keeper and a latch member for engaging the latch keeper. The latch keeper is associated with the dipper body proximate the open dipper bottom and the latch member is coupled to the dipper door. The latch member includes at least one roller to assist the latch member in engaging and disengaging with the latch keeper and to reduce wear on the latch member.

Claims

1-23. (canceled)

24. A latch assembly for use with a dipper assembly of a mining shovel, the latch assembly comprising: (a) a latch keeper configured to be associated with a dipper body proximate an open dipper bottom of the dipper body; (b) a latch member configured to be coupled to a dipper door for engaging with the latch keeper and releasably securing the dipper door in a closed position closing the open dipper bottom, the latch member comprising: (i) an outer surface; (ii) an opposed inner surface configured to face the dipper door: (iii) a pair of opposed side edges; (iv) an upper end edge; (v) an opposed lower end edge; and (vi) a recessed portion defined in the lower end edge, the recessed portion being defined between two opposed side edge portions and a portion of the inner surface protruding downwardly from the lower end edge; and (c) a roller assembly mountable within the recessed portion of the latch member, the roller assembly comprising at least one roller configured to assist the latch member in disengaging with the latch keeper and to at least partially reduce wear on the latch member.

25. The latch assembly of claim 24, wherein the at least one roller is a cylindrical metal pin rotatably mounted between the two side edge portions.

26. The latch assembly of claim 24, wherein the at least one roller rotates on roller journals fitted to or housed within the two side edge portions.

27. The latch assembly of claim 24, wherein the roller assembly is detachably mounted to the latch member.

28. The latch assembly of claim 24, wherein the roller assembly further comprises a pair of roller mounts coupled to each end of the at least one roller and configured to be mounted to the two side edge portions of the latch member so that the at least one roller can freely rotate relative to the lower end of the latch member.

29. The latch assembly of claim 24, wherein the recessed portion is configured to at least partially accommodate the roller assembly.

30. The latch assembly of claim 24, wherein the recessed portion is configured to at least partially shield the roller assembly from fines and other debris contained within the dipper body from clogging the at least one roller and preventing rotation of the at least one roller.

31. The latch assembly of claim 24, wherein the roller assembly further comprises a shield portion configured to partially couple around the at least one roller and at least partially shield the roller assembly from fines and other debris from the dipper body from clogging the at least one roller and preventing rotation of the at least one roller.

32. The latch assembly of claim 28, wherein the side edge portions each comprise an opening extending therethrough for at least partially receiving and holding one of the roller mounts of the roller assembly.

33. The latch assembly of claim 28, wherein each roller mount further comprises a connecting pin protruding from a circular sidewall of the mount and configured to be received in a corresponding hole defined in the opening to further secure the roller assembly to the recessed portion of the latch member.

34. The latch assembly of claim 24, further comprising a latch lever member coupled to the latch member and configured to pivot between raised and lowered positions to slide the latch member between a retracted position in which the latch member disengages from the latch keeper and an extended position in which the latch member is able to engage with the latch keeper.

35. The latch assembly of claim 34, wherein the latch lever member comprises a pair of opposed surfaces comprising an outer surface and an opposed inner or dipper facing surface, the opposed surfaces interconnected by opposing edges, the latch lever member extending longitudinally between opposed ends comprising a first end pivotally mounted to the dipper door and an opposed second end pivotable between the raised and lowered positions.

36. The latch assembly of claim 35, wherein the latch lever member extends through an opening defined in an upper end portion of the latch member and is coupled to the latch member at a location proximate the first end of the latch lever member.

37. The latch assembly of claim 36, wherein the location of the latch lever member coupled to the latch member comprises a curved, contoured upper surface.

38. The latch assembly of claim 37, wherein the opening defined in the upper end portion of the latch member further comprises a wear insert configured to be disposed within an upper portion of the opening to at least partially reduce wear of the latch member and latch lever member as they move relative to one another, and wherein the wear insert comprises a curved, contoured lower surface configured to substantially complement the curved contoured upper surface of the latch lever member.

39. The latch assembly of claim 38, wherein the latch lever member comprises one or more plain bearings disposed on the opposed surfaces to provide a bearing surface between the latch lever member and the latch member as they move relative to one another.

40. The latch assembly of claim 39, wherein the one or more plain bearings act as bearing surfaces against an inner side wall of the opening in the latch member through which the latch lever member extends.

41. The latch assembly of claim 35, further comprising a housing and pin assembly configured to receive and pivotally mount the first end of the latch lever member to the dipper door.

42. A dipper door for use with a dipper assembly of a mining shovel comprising the latch assembly of claim 24 for releasably securing the door in the closed position, wherein the door is configured to be pivotally coupled to a dipper body comprising an open dipper bottom for movement between a closed position in which the door closes the open dipper bottom and an open position in which the dipper door is positioned away from the open dipper bottom.

43. A dipper assembly for a mining shovel, the dipper assembly comprising: (a) a dipper body comprising a back wall and an open dipper bottom; and (b) a dipper door pivotally coupled to the back wall for movement relative to the dipper body between a closed position in which the door closes the dipper bottom and an open position in which the door is positioned away from the dipper bottom, wherein the latch assembly is configured for releasably securing the door in the closed position.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0156] Preferred features, embodiments and variations of the invention may be discerned from the following Detailed Description which provides sufficient information for those skilled in the art to perform the invention. The Detailed Description is not to be regarded as limiting the scope of the preceding Summary of Invention in any way. The Detailed Description will make reference to a number of drawings as follows:

[0157] FIG. 1 is a perspective view of a prior art mining shovel;

[0158] FIG. 2 is a lower perspective view of a prior art dipper assembly having a dipper body and a dipper door pivotally coupled to the dipper body;

[0159] FIG. 3 is a perspective view of a dipper door and latch assembly according to an embodiment of the present invention;

[0160] FIG. 4 is an expanded view of part of the latch assembly shown in FIG. 3;

[0161] FIG. 5 is an exploded view of the part of the latch assembly shown in FIG. 4;

[0162] FIG. 6 is another semi-exploded view of the part of the latch assembly shown in FIG. 4;

[0163] FIG. 7 is a perspective view of a latch member of the latch assembly as shown in FIGS. 3 to 6;

[0164] FIGS. 8A and 8B are perspective views of a roller located at an end of the latch member shown in FIG. 7;

[0165] FIG. 9 is a perspective view of a latch lever member of the latch assembly as shown in FIGS. 3 to 6; and

[0166] FIGS. 10A and 10B respectively show sectional views of the latch member of the latch assembly as shown in FIGS. 4 to 6 in an extended position and in a retracted position.

DETAILED DESCRIPTION

[0167] FIG. 1 shows a prior art mining shovel (900). The shovel (900) includes a mobile base (910) having drive tracks (920) for movement along a ground surface, a turntable (930) mounted atop the mobile base (910), and a revolving frame (940) mounted atop the turntable (930).

[0168] The revolving frame (940) includes a boom (950). The boom (950) is coupled to a dipper assembly (800; best shown in FIG. 2) by way of a hoist cable (960) extending over a boom sheave (952) associated with an upper end of the boom (950) and a pair of dipper handles (970) that are slidably mounted to saddle blocks (980) pivotally mounted to each side of the boom (950).

[0169] The turntable (930) defines a rotational axis of the shovel (900) and enables the revolving frame (940), including the boom (950), dipper handles (970) and dipper assembly (800), to rotate relative to the mobile base (910) and drive tracks (920).

[0170] The boom (950) is pivotally coupled at a lower end to the revolving frame (940) and extends upwardly and outwardly from the revolving frame (940).

[0171] The dipper assembly (800) is suspended from the upper end of the boom (950) by the hoist cable (960). The hoist cable (960) extends up the boom (950) and over the boom sheave (952) to connect at a first end to the dipper assembly (800) via a bail (890). The hoist cable (960) is anchored at an opposite second end to a hoist drum (not visible) associated with the revolving frame (940). The hoist drum (not visible) is driven by an electric motor. The hoist cable (960), in use, is paid out or reeled in by the hoist drum (not visible) to respectively lower or raise the dipper assembly (800).

[0172] During a hoist phase, the hoist cable (960) is reeled in by the hoist drum (not visible) to lift the dipper assembly (800) upward through a bank of earthen material and liberating the material to be dug.

[0173] Each dipper handle (970) includes a rack and tooth formation thereon to engage a drive pinion mounted in each saddle block (980). The drive pinion is driven by an electric motor to extend or retract each dipper handle (970) relative to the saddle block (980). In use, each handle (970) is moveable along a respective saddle block (980) to manoeuvre and position the dipper assembly (800).

[0174] Referring to FIG. 2, the dipper assembly (800) includes a dipper body (810) and a dipper door (100) pivotally coupled to the dipper body (810). The dipper door (100) is releasably secured to the dipper body (810) by a latch assembly (200) enabling the door (100) to be selectively opened to unload earthen material contents atop a desired deposit location, such as, e.g., the bucket of a dump truck.

[0175] The dipper body (810) has a substantially rectangular cross-sectional shape defined by four walls, including the back wall (812), an opposed front wall (814), and a pair of opposed sidewalls (815) extending between the back wall (812) and the front wall (814).

[0176] Each wall (812, 814, 815) includes an inner surface and an opposed outer surface.

[0177] Each wall (812, 814, 815) extends longitudinally between a lower edge and an opposed upper edge.

[0178] The dipper body (810) includes rounded corners extending between adjacent walls (812, 814, 815).

[0179] The dipper body (810) includes open ends for receiving and depositing the earthen materials liberated from a bank of a mine. The open ends include an open dipper mouth (811) for receiving the earthen materials and an open dipper bottom (813) located opposite the open dipper mouth (811) and from where the earthen materials are unloaded.

[0180] The mouth (811) and bottom (813) are defined by an upper rim and a lower rim extending at least partially along the upper and lower edges of the walls (812, 814, 815) of the dipper body (810), respectively.

[0181] The upper rim defines the open dipper mouth (811). Likewise, the lower rim defines the open dipper bottom (813).

[0182] The dipper body (810) includes a plurality of teeth (819; best shown in FIG. 1) extending along the upper rim of the front wall (814) of the dipper assembly (800) to contact and engage earthen materials as the dipper assembly (800) is moved through a hoist cycle by the action of the shovel (900; shown in FIG. 1 only).

[0183] As mentioned, the dipper door (100) is pivotally coupled to the back wall (812) of the dipper body (810) for movement relative to the dipper body (810) between a closed position in which the door (100) closes the dipper bottom (813) and an open position in which the door (100) is positioned away from the dipper bottom (813).

[0184] The dipper door (100) includes a pair of L-shaped dipper door lugs (120). The lugs (120) extend from the dipper door (100) past the back wall (812) of the dipper body (810) and are pivotally coupled with a pivot pin to dipper door mounting lugs (825) located on an outer surface of the back wall (812) of the dipper body (810).

[0185] As shown, the back wall (812) of the dipper body (810) includes further protruding lugs (827) for mounting the dipper assembly (800) to the dipper handles (970; shown only in FIG. 1).

[0186] The dipper assembly (800) includes a latch assembly (200) for releasably securing the dipper door (100) in the closed position. The latch assembly (200) includes a latch keeper (832) associated with the dipper body (810) and a latch member (210) coupled to the dipper door (100) and configured to engage with the latch keeper (832) to releasably secure the dipper door (100) in the closed position as shown.

[0187] The latch member (210) of the assembly (200) is moveable between an extended position in which the dipper door (100) is secured in the closed position and a retracted position in which the dipper door (100) is able to move to the open position.

[0188] The latch member (210) is biased into the extended position by a biasing member or mechanism associated with a trip wire or cable assembly (not shown). Tripping of the trip wire or cable assembly by a shovel operator causes the latch member (210) to temporarily move to the retracted position against the force of the biasing member or mechanism before the latch member (210) is biased back into the extended position under the force of the biasing member or mechanism in preparation for re-latching of the dipper door (100).

[0189] The latch keeper (832) is in the form of an opening defined in the front wall (812) of the dipper body (810) proximate the open dipper bottom (813). The latch keeper (832) is defined mid-way along the lower rim of the front wall (812) of the dipper body (810).

[0190] Referring to FIG. 3, the dipper door (100) is of a size, shape and construction to cover the open dipper bottom when in the closed position.

[0191] The dipper door (100) is formed from metal.

[0192] The dipper door (100) has a substantially rectangular shape and includes an inner surface (101) and an opposed outer surface (102). The inner and outer surfaces (101, 102) are interconnected by opposing edges, including an outer edge (104) configured to abut the lower rim of the front wall of the dipper body, an opposed inner edge (103) configured to abut the lower rim of the back wall of the dipper body and opposed side edges (105).

[0193] The dipper door (100) includes structural support ribs (110) for imparting greater structural rigidity to the dipper door (100). As shown, the structural support ribs (110) are spaced apart across the outer surface (102) of the door (100) and the latch assembly (200) is partially mounted between two of the support ribs (110).

[0194] The latch assembly (200) includes the latch member (210) and a latch lever member (220).

[0195] The latch member (210) is slidably mounted to the outer surface (102) of the dipper door (100) to engage with a latch keeper associated with the dipper body to releasably secure the dipper door (100) in the closed position. The latch member (210) longitudinally extends at least partially across the dipper door (100) from the outer edge (104) at least partially towards the inner edge (103) in a direction substantially perpendicular to the inner and outer edges (103, 104).

[0196] Referring briefly now to FIG. 7, the latch member (210) is formed from metal and has an elongate shape having a lower end (212) and an opposed upper end (214). The latch member (210) is bar-shaped and of solid construction having a substantially rectangular profile shape.

[0197] The latch member (210) includes two opposed surfaces, including an outer surface (211) and an opposed inner surface (213) configured to face the dipper door (100; not shown). The opposed surfaces (211, 213) extend substantially parallel to one another and are interconnected by opposing edges, including a pair of opposed side edges and a pair of opposed end edges.

[0198] The latch member (210) includes an opening (219) in an upper end portion (214A) for receiving the latch lever member (220) therethrough. The opening (210) extends entirely through the latch member (210) forming a channel extending between the opposed side edges.

[0199] The latch member (210) includes a flared lower end portion (212A). The flared lower end portion (212A) has a greater width and/or thickness than the upper end portion (214A).

[0200] The lower end (212) of the latch member (210) includes recessed portion defined by two protruding side edge portions (215A) for at least partially accommodating a roller assembly (230), including a shield portion (213A).

[0201] The roller assembly (230) is for assisting the latch member (210) in disengaging with a latch keeper and to at least partially reduce wear on the latch member (210).

[0202] Advantageously, the shield portion (213A), in use, at least partially shields the roller assembly (230) from fines and other debris contained within the dipper that could otherwise clod and impede a roller (232) of the roller assembly (230) from free rotation.

[0203] Each protruding side edge portion (215A) includes an opening extending therethrough for receiving and holding the roller assembly (230).

[0204] Referring to FIGS. 8A and 8B, the roller assembly (230) includes the roller (232) in the form of a cylindrical metal pin or sleeve, and a pair of roller mounts (234) rotatably coupled to each end of the roller (232) and configured to be received within the channels of the protruding side edge portions so that the roller (232) can freely rotate.

[0205] The roller assembly (230) further includes the shield portion (213A), which is formed from plastic and is adapted to partially couple around the roller (232) so as to at least partially shield the roller (232) from fines and other debris contained within the dipper but not, in use, prevent rotation of the roller (232) when, e.g., the latch member is disengaging from the latch keeper. The shield portion (213A) is a separate, removable and replaceable element.

[0206] The pair of roller mounts (234) each have a circular profile shape, including a circular sidewall extending outwardly from an end of the roller (232) to an outer mount end (236). Each mount (234) further includes a connecting pin (238) protruding outwardly from the circular sidewall and configured to be received within a corresponding hole defined in a wall of each opening of the protruding side edge portions.

[0207] Referring back to FIG. 3, the latch member (210) is partially disposed within the dipper door (100). The dipper door (100) includes a latch member housing (120) forming a channel that extends between an interior of the dipper door (100) to an external surface.

[0208] The cavity of the latch member housing (120) is sized and shaped to receive the flared lower end portion (212A; not visible) of the latch member (210) therethrough and enable the lower end (212) to protrude past an external exit of the channel for engagement with a latch keeper.

[0209] The latch lever member (220) is coupled to the latch member (210) and is pivotable between lowered and raised positions to respectively slide the latch member (210) between an extended position in which the lower end (212) of the latch member (210) extends past the outer edge (104) of the dipper door (100) for engagement with a latch keeper associated with the dipper body and a retracted position in which the lower end (212) of the latch member (210) at least partially retracts for disengagement from the latch keeper.

[0210] The latch lever member (220) has an elongate shape extending between a first end (222; not visible) pivotally mounted to the dipper door (100) and an opposed second end (224; not visible) pivotable between the lowered and raised positions.

[0211] As shown, the latch lever member (220) extends laterally across the dipper door (100) with the second end (224; not visible) being located at or near a side edge (105) of the dipper door (100) for connection with a trip wire or cable assembly (700) or component thereof.

[0212] Referring briefly to FIG. 9, the latch lever member (220) is formed from metal and is bar-shaped. The latch lever member (220) is of solid construction.

[0213] The latch lever member (220) include two opposed surfaces, including an outer surface and an opposed inner surface or dipper door facing surface. The opposed surfaces extend substantially parallel to one another and are interconnected by opposing edges. The opposing edges include a pair of opposed side edges and/or a pair of opposed end edges.

[0214] The opposed side edges include one or more contours and the opposed end edges are rounded.

[0215] Referring to FIGS. 10A and 10B, the latch lever member (220) and the latch member (210) are coupled together such that the first end (222) of the latch lever member (220) is received through the opening (219) defined in the upper end portion (214A) of the latch member (210) and is pivotally mounted to the dipper door (100) via a housing and pin assembly (400).

[0216] The latch lever member (220) includes a curved portion (225; also shown in FIG. 9) proximate to the first end (222) that is received and located within the opening (219) of the latch member (210) when the members (210, 220) are coupled together.

[0217] In this regard, the opening (219) of the latch member (210) further includes a wear insert (240) configured to be disposed within an upper portion of the opening (219) to at least partially reduce wear of the latch member (210) and the latch lever member (220) as they move relative to one another.

[0218] The wear insert (240) is formed from nylon and includes a curved, contoured lower surface (242) configured to complement the curved portion (225) of the latch lever member (220). The surfaces act together as bearing surfaces to permit some rotation and relative movement in at least one degree of freedom between the insert (240) and the latch lever member (220) thereby inhibiting wear and unwanted stress from damaging the coupling of the latch assembly (200).

[0219] The opposed surfaces of the latch lever member (220) each also include a pair of plain bearings (250) disposed thereon. The plain bearings (250) providing bearing surfaces between the latch lever member (220) and the lever member (210) as they move relative to one another. The bearings (250) act as bearing surfaces against an inner side wall of the opening (219) in the lever member (210) through which the latch lever member (220) extends.

[0220] Each plain bearing (250) is a separate, removable and replaceable element to the latch lever member (220).

[0221] The plain bearings (250) are formed from a durable, low friction, low wear, heat resistant and corrosion resistant material or materials, such as, e.g., plastic, including nylon, polyacetal, polytetrafluoroethylene (PTFE), ultra-high-molecular-weight polyethylene (UHMWPE), rulon, PEEK, urethane or vespel (a high-performance polyimide).

[0222] Each plain bearing (250) includes a wide head having a substantially flat shape configured to rest against the surface of the latch lever member (220) and act as a bearing surface. Each plain bearing (250) further includes a shank (not shown) extending from the head and configured to be received in a corresponding opening in the lever member (220).

[0223] The plain bearing (250) are fitted in pairs on opposite sides of the latch lever member (220). Each bearing (250) of a pair is inserted into opposite sides of the same corresponding opening and the shanks are connectable to secure the bearings in place, e.g., threadingly connectable.

[0224] The wide head of each bearing (250) includes a socket or other tool engaging formation (252) for receipt of a tool to turn the bearing (250) and threadingly connect the bearing (250) with a paired bearing (250) received in an opposite side of the opening.

[0225] Referring to FIG. 4, the housing and pin assembly (400) is configured to receive and pivotally mount the first end (222) of the latch lever member (220).

[0226] The housing and pin assembly (400) includes an outer housing (410) configured to be fastened to the dipper door (100), a pin (420) coupled to the outer housing (410), and a carrier (430) for receiving the first end (222) of the latch lever member (220). The carrier (430) is configured to be slidably mounted to the pin (420) and be received within the outer housing (410).

[0227] Referring to FIG. 5, the outer housing (410) include an upper wall (412), an opposed lower wall (414) and a pair of opposed side walls (416) extending between side edges of the upper and lower walls (412, 414). Each of the walls (412, 414, 416) includes an inner surface and an opposed outer surface.

[0228] The pair of opposed sidewalls (416) define a passage therebetween for accommodating the carrier (430) and the first end (222) of the latch lever member (220).

[0229] The upper wall (412) and the lower wall (414) of the outer housing (410) each include a pin receiving lug (422) extending outwardly from a common end edge away from the latch lever member (220). Each pin receiving lug (422) includes a central bore therethrough for receiving the pin (420; not shown).

[0230] The carrier (430) also includes an upper wall (432), an opposed lower wall (434) and a pair of opposed sidewalls (436) extending between side edges of the upper and lower walls (432, 434). Again, each of the walls (432, 434, 436) includes an inner surface and an opposed outer surface.

[0231] The pair of opposed sidewalls (436) defines a passage therebetween for receiving the first end (222) of the latch lever member (220).

[0232] The upper and lower walls (432, 434) of the carrier (430) each includes a pin receiving lug (422) for slidably mounting the carrier (430) to the pin (420; not shown) connected to the outer housing (410). The carrier (430) is slidable along the pin (420; not shown) within the outer housing (410).

[0233] Referring to FIG. 6, the housing and pin assembly (400) further includes a plurality of shims (i.e., spacers; 440), for fitting between the inner surfaces of the upper and lower walls (412, 414) of the outer housing (410) and the outer surfaces of the upper and lower walls (432, 434) of the carrier (430).

[0234] Each shim has a substantially elongate and flat shape and at least partially complements or accommodates the pin (420) of the housing and pin assembly (400) to, in use, assist in retaining the shim (440) within the assembly (400).

[0235] The plurality of shims (440) are of differing thicknesses.

[0236] In use, the shims (440) can be added and/or replaced to at least partially reduce and/or offset any wear between the outer housing (410) and the carrier (430) of the housing and pin assembly (400). Moreover, the shims (440) can be added, replaced and/or removed to readily adjust an alignment of the latch lever member (220) and latch member (210) relative to one another, particularly as components of the latch assembly (200) wear with use, thereby advantageously enabling prolonged acceptable operation of the latch assembly (200).

[0237] Referring again to FIG. 5, the first end (222) of the latch lever member (220) and the carrier (430) are pivotally coupled together by a pair of pivot pins (510) received within co-aligned corresponding bores (226, 438) defined in the first end (222) and the sidewalls (436) of the carrier (430).

[0238] The central bore (226) of the latch lever member (220) includes a self-lubricating spherical bushing (228) disposed within the bore (226).

[0239] Each of the pair of pivot pins (510) includes a head (512), an opposed end (514) and a shank extending therebetween.

[0240] The shank of each pin (510) is sized and shaped to be received through the central bores (226, 438) and an inner aperture of the bushing (228).

[0241] The head (512) of each pin (510) is sized and shaped to not pass through the bores (226, 438) and the inner aperture but abut against an outer surface of a sidewall (436) of the carrier (430) and thereby prevent the bushing (228) from moving axially within the central bore (226).

[0242] The head (512) of each pin (510) also has a non-circular shape to align and/or fix rotation of the pin (510) relative to the bores (226, 438) and the bushing (228).

[0243] In particular, the central bores (438) of the carrier (430) each include a countersunk outer opening having a non-circular shape configured to complement and at least partially receive the non-circular profile shape of the head (512) of a pivot pin (510)

[0244] Each of the pair of pivot pins (510) includes a central aperture axially extending entirely therethrough configured to receive a mechanical fastener (518) to fasten the pins (510) together in an end (514) to end (514) arrangement.

[0245] Referring to FIG. 4, the upper end (214) of the latch member (210) include an engagement portion (260) to facilitate easy gripping and/or removal of the latch member (210) from the latch assembly (200) to repair or replace the latch member (210).

[0246] The engagement portion (260) includes a protruding flange with an aperture therethrough.

[0247] Also shown in FIG. 4, the dipper door (100) includes a retention plate (170) configured to be fitted over an entrance to the latch member housing (120) for retaining or at least partially preventing the latch member (210) from overly retracting into the dipper door (100).

[0248] The retention plate (170) includes an aperture (172) therethrough sized and shaped to enable an upper end portion (214A) of the latch member (210) to pass through but not the flared lower end portion (212A; not visible) of the latch member (210). The retention plate (170) is fastened over the entrance, by, e.g., one or more mechanical fasteners.

[0249] Movement of the latch member (210) between the extended and retracted positions will now be described in detail with reference to FIGS. 10A and 10B.

[0250] FIG. 10A shows the latch member (210) of the latch assembly (200) in the extended position. In this position, the dipper door (100) is latched in the closed position across the open dipper bottom of the dipper body, which likely contains a load of earthen materials.

[0251] When a mining shovel operator has positioned the dipper assembly over a desired deposit location, the operator trips the trip wire or cable assembly, which is coupled to the second end (224) of the latch lever member (220), and temporarily forces the second end (224) of the latch lever member (220) to the raised position.

[0252] Movement of the second end (224) of the latch lever member (220) to the raised position causes the latch lever member (220) to pivot about the first end (222) and the curved portion (225) to move upwards in the opening (219) of the latch member (210) against the wear insert (240) and thereby slide the latch member (210) into the retracted position as shown in FIG. 10B.

[0253] Movement of the latch member (210) into the retracted position disengages the lower end (212; not shown) from a latch keeper associated with the dipper body allowing the dipper door (100) to pivot into the open position and deposit the earthen materials atop the desired deposit location.

[0254] A biasing member or mechanism associated with the trip wire or cable assembly biases the latch member (210) back into the extended position for relatching of the dipper door (100) with the dipper body by moving the second end (224) of the latch lever member (220) into the lowered position.

[0255] Movement of the second end (224) of the latch lever member (220) to the lowered position causes the latch lever member (220) to pivot about the first end (222) and the curved portion (225) to move downwards in the opening (119) of the latch member (210) and slide the latch member (210) back into the extended position for relatching with a latch keeper associated with the dipper body as shown in FIG. 10A.

[0256] In the present specification and claims (if any), the word ‘comprising’ and its derivatives including ‘comprises’ and ‘comprise’ include each of the stated integers but does not exclude the inclusion of one or more further integers.

[0257] Reference throughout this specification to ‘one embodiment’ or ‘an embodiment’ means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrases ‘in one embodiment’ or ‘in an embodiment’ in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more combinations.

[0258] In compliance with the statute, the invention has been described in language more or less specific to structural or methodical features. It is to be understood that the invention is not limited to specific features shown or described since the means herein described comprises preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims (if any) appropriately interpreted by those skilled in the art.