AU662027B2

AU662027B2 - Surface mining shovel

Info

Publication number: AU662027B2
Application number: AU29899/92A
Authority: AU
Inventors: Charles L. Wadsworth
Original assignee: Harnischfeger Corp
Current assignee: Harnischfeger Corp
Priority date: 1991-12-09
Filing date: 1992-12-04
Publication date: 1995-08-17
Anticipated expiration: 2012-12-04
Also published as: BR9204838A; CH687999A5; CA2060473C; AU2989992A; ZA929547B; DE4238418A1; CN1074263A; JPH05255946A; CA2060473A1

Description

'.3 662027

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

S F Ref: 226761 tC S C C C C Cr g cr Name and Address of Applicant: Actual Inventor(s): Address for Service: Invention Title: Harnischfeger Corporation 13400 Bishops Lane Brookfield Wisconsin 53005 UNITED STATES OF AMERICA Charles L. Wadsworth Spruson Ferguson, Patent Attorneys Level 33 St Martins Tower, 31 Market Street Sydney, New South Wales, 2000, Australia Surface Mining Shovel The following statement is a full description of this invention, including the best method of performing it known to me/us:-

L~

I SURFACE MINING SHOVEL Field of the Invention This invention relates to a surface mining shovel having a highly effective crowd mechanism, a high digging force and a long digging reach. More particularly, the invention relates to a mining shovel having a handle mounted on a boom and pivotally moved by a rope hoist and a hydraulic crowd mechanism which moves the boom to provide crowd movement for the handle.

Background of the Invention Surface mining shovels, particularly larger shovels, 10 utilize wirr rope hoists for pivoting the handle on which the dipper iz supported and lifting the dipper. Such hoists are reliable and have low maintenance. They can ,,ct be supported on sheaves at the upper end point of a long boom to provide a long digging reach for the shovel.

Because of the long boom in combination with the rope hoist, a high cutting force is produced when digging into high earth banks. Also, the wire rope hoist provides a high degree of shock absorption during digging compared to other attachment methods. It further minimizes the amount of structural weight which must be lifted with each digging stroke compared to other melihods. The crowd mechanism is typically of a rack and pini6n type in which a bifurcated handle straddling the booz- is moved by the crowd mechanism in the direction of the length of the i -2handle outward from the boom. Because of this type of crowd movement, it has proven to be difficult to provide a practical method to enable tilting of the dipper assembly. Consequently, the dipper is fixed in its position on the end of the handle so that it cannot be provided with varying pitch positions to optimize the pitch for different positions in the bank. As a result, when the handle and dipper are pivoted to a downward position on the floor of the digging area, the pitch of the dipper cannot be adjusted to keep the tooth direction in line with the direction of dipper movement or enable t greater dipper movement ability in a linear direction.

Thus, the ability to make an extended cut at floor level is limited. The lack of dipper pitch adjustment also limits the shovel in its flexibility to carry out a number of other digging movements, such as prying material loose.

During application of crowd force, as the dipper is moved into the earth material being dug, the opposing force of the earth material is transmitted back to the boom. In response, the boom, which is pivotally mounted on the frame of the shovel, pivots back or "jacks". This movement of the boom, depending on operator skill, can limit the amount of crowd force that can be applied and also causes stressing of the boom support ropes. The rack and pinion crowd, besides permitting boom jacking, is a very expensive structure to build and requires some degree of maintenance skill.

-3nf tIhP Tnvpnfinn It is the object of the present invention to overcome or substantially ameliorate the above disadvantages.

There is disclosed herein a surface mining shovel for digging into and moving earth material, the shovel having a frame including a working end, comprising: a gantry support extending upward from the frame; a boom extending upward from and pivotally mounted on the frame at a location adjacent the working end of the frame; a handle mounted on the boom for pivotal movement relative thereto about an axis; a dipper mounted on the handle and engageable with the earth material as the handle pivots; hoist means for pivoting the handle to engage the dipper with the earth material and lift the dipper; and crowd means connected to the boom and to the gantry support, the connection of the 'rowd means to the boom being at a location spaced from said axis, the connection of the crowd means to the gantry support being at a position above the location at which the boom is mounted on the frame, for pivoting the boom and moving the dipper on the handle into the earth material whereby the earth material enters the dipper and can be lifted with the dipper as the handle is pivoted by the hoist means.

There is further disclosed herein a surface mining shovel for digging and moving earth material, the shovel having a frame including a working end, comprising; a boom extending upward from the frame and having upper and lower ends, 25 the lower end of the boom being mounted at a location on the frame adjacent the working end of the frame; dipper means for digging into and carrying the earth material; S an elongated handle having first and second opposite ends, the handle being mounted for pivotal movement on the upper end of the boom at a pivot point intermediate the opposite ends of the handle, the dipper means being mounted on the 30 second end of the handle and pivotally movable with the handle along a path into the earth material; hoist means connected to the handle adjacent the first end of the handle for s.e: pivoting the handle and the dipper about the pivot point on the boom along said path of Sthe dipper into the earth material; and t t I 35 crowd means connected to the boom and to the frame, the crowd means being t I connected to the boom at a point spaced from said-pivot podintthe crowd means being connected to the frame at a position above the boom for mot andle and hd an Sdipper on the handle along said path into the earth material e ent by 15 e -4crowd means of the handle and the dipper being simultaneous with the pivotal movement of the handle to move the dipper along the path into the earth material, whereby the movement of the handle due to both the crowd means and hoist means provides a high dipper digging force into the earth material.

There is still further disclosed herein a method of digging into earth material with a surface mining shovel having a frame, a boom pivotally mounted on and extending upwardly from the frame, an elongated handle pivotally mounted on the boom, a dipper affixed to an end of the handle, and crowd means connected to the boom and the frame, comprising the steps of: pivoting the handle on the boom to move the dipper into engagement with the earth material; and applying force from a position above the pivotal mounting of the boom on the frame directly to the boom, at a point spaced from the pivotal connection of the handle and the boom, with the crowd means in a digging direction to move the handle and thereby the dipper to dig into the earth material.

There is still further disclosed herein a surface mining shovel for digging into and moving earth material, the shovel comprising: a frame including a working end; a boom extending upward from and pivotally mounted on the frame at a location adjacent the working end of the frame; a handle mounted on the boom for pivotal movement relative thereto about an axis; a dipper mounted on the handle and engageable with the earth material as the handle pivots; 25 a hoist mechanism for pivoting the handle to engage the dipper with the earth material and lift the dipper; and .a crowd mechanism connected to the boom Prnd to the frame, the crowd i :mechanism being connected to the boom at a first point spaced from said axis, the crowd mechanism being connected to the frame at a second point, and the crowd mechanism being operable to force the first point away from the second point so as to force the dipper into the earth material.

There is still further disclosed herein a surface mining shovel for digging into and moving earth material, the shovel comprising: a frame including a working end; 35 a gantry support extending upwardly from the frame; a boom extending upward from the frame and having upper and lower ends, the lower end of the boom being pivotally mounted on the frame at a location adjacent t .'-the working end of the frame; N -(N:llbtt)00O529HRW -4aa handle mounted on the upper end of the boom for pivotal movement relative thereto about an axis, the handle having upper and lower ends, the handle being pivotally connected to the boom at a point intermediate the upper and lower erds of the handle; a dipper mounted on the handle adjacent the lower end thereof and engageable with the earth material as the handle pivots; a hoist mechanism for pivoting the handle to engage the dipper with the earth material and lift the dipper, the hoist mechanism including a rotatable drum mounted on the frame and a rope connected to the handle adjacent the upper end thereof and windable on to and off of the drum; and a crowd mechanism connected to the boom and to the gantry support, the crowd mechanism being connected to the boom at a first point spaced from the axis, the crowd mechanism being connected to the gantry support at a second point, the second point being abc', the first point and above the pivotal connection of the boom to the frame, the crowd mechanism including an extendible and contractible hydraulic device, and the crowd mechanism being operable to force the first point away from the second point by extending the hydraulic device so as to force the dipper into the earth material.

Brief Description of the Drawings Further objects and advantages of the invention will appear when taken into conjunction with the accompanying drawings in which: Fig. 1 is a perspective view of a surface mining shovel incorporating the present invention; 4 i

I

s~a f *t l *r C C it I (C t C"

C

I

IN:\Ilbl00629SHRW FIG. 2 is a side elevation view of the surface mining shovel shown in FIG. 1 and illustrating various positions of the shovel as it moves through digging and lifting operations; FIG. 3 is a side elevation view of a surface mining shovel incorporating an alternate embodiment of the invention; FIG. 4 is a plan view of the shovel shown in FIG. 2 I..f with portions of the shovel broken away; 10 FIG. 5 is a cross-sectional view, with portions broken away, taken along lines 5-5 of FIG. 2; :FIG. 6 is a cross-sectional view taken along lines 6-6 of FIG. 2; and FIG. 7 is a cross-sectional view, with portions 15 broken away, taken along lines 7-7 of FIG. 3.

t Detailed Description of the Invention Referring generally to Figures 1 and 2, a surface mining shovel is illustrated as having a revolving frame

I

2 including a base 4, a gantry 6 extending upward from the base 4, a machinery house 8 mounted on the frame 2, an operator's cab 10 mounted on the machinery house 8, a hydraulic supply system 11, and a crawler frame 12 on which the frame 2 is revolvingly supported. The crawler frame 12 includes a car body 14, side frames (only one of which is shown), and an upwardly projecting slewing ring 18. The ring 18 is surrounded by and engages a downwardly projecting slewing ring 20 which is part of -6the frame 2 to thereby support the frame 2. The frame 2 is revolving driven on the crawler frame 12 by a pair of electric swing motors and gear drives 22 which engage teeth along the periphery of the ring 20. The side frames extend laterally from opposite sides of the car body 14. A crawler track 24a is supported for continuous movement on the tumbler of a propel drive 28 and on rollers 26 mounted on the side frame 16 shown in Figs. 1 and 2. A crawler track 24b is supported on rollers (not shown) similar to rollers 26 mounted on a side frame 9'9 similar to the shown side frame 16 and on a propel drive .9,9 (not shown) similar to propel drive 28. Each of the propel drives comprises an electric motor driven transmission gear for driving the crawler tracks and moving the shovel along the ground.

With reference to FIG. 1, 2 and 4, the gantry 6 has an aft leg 82 affixed to the base 4 and a pair of front legs 84 and 86 affixed to the base 4 adjacent to a working or front end 34 of the base. The aft leg 82 has 20 an upper head 88 to which the front legs are also affixed.

With reference to FIGS. 1i, 2 and 4-6, the surface mining shovel further includes a boom 30 pivotally mounted on the base 4 by pins 32 adjacent to the front end 34 of the base of frame 2, an elongated handle 36 having upper and lower oppositely extending sections 37 and 39 respectively including opposite upper and lower ends 38 and 40, the handle being pivotally mounted by i; -7pins 42 on the boom 30 intermediate the ends, and a dipper 44 pivotally affixed to the lower end 40 of the handle for digging into and lifting earth material 90. A hoist 46 is mounted on the frame 2 within the machinery house 8 and includes an electric motor 48, a rotatable drum 50 driven by the motor, a pair of hoist ropes 52 connected to the drum 50 and to the end 38 of the handle by an equalizer 54. The drum 50 is rotated by the motor to pay the ropes out so that the handle pivots downward ."eP0 about the boom due to the weight of the handle and dipper "t to thereby lower the dipper, to swing the dipper 4*4i a t counterclockwise relative to the view of FIG. 2. The drum is also rotatable by the motor to wind the ropes in or on to the drum to rotate the handle to swing the 4.4.15 dipper clockwise and upward relative to the view of FIG.

4 4.

2. The dipper 44 comprises a front 56 and a back 58 S pivotally connected to the handle 36 at pins 60. The dipper front 56 is pivotally connected to the back 58 at pins 62 to allow the back and front to pivotally move 20 apart about pins 62 and dump any load in the dipper. A pair of hydraulic cylinders 64, only one of which is shown, are connected between the back and the front of the dipper for opening and closing the front and back. A pair of hydraulic cylinders 66a and 66b are pivotally connected by pins 68 to handle 36 and by pins 70 to the back 58 of the dipper. The cylinders 66a and 66b control the pitch of the dipper to provide it with the desired "angular attitude when the dipper is at a low or 8 8 intermediate height position for digging into earth material 90, at an intermediate or high height position for lifting earth material, or at a dumping position. A pair of hydraulic cylinders 72a and 72b are pivotally connected to the gantry by pins 78 at the head 88 and include pistons 74a and 74b pivotally connected by pins 76 to the boom 30. The cylinders 72a and 72b provide crowd movement for the dipper 44 by pivoting the boom about pins 32 away from the frame 2 so that the handle 10 and the dipper on the end 40 of the handle move downward t and away from the frame. The dipper 44 thereby moves Ott$

A

S along a path into the earth material 90 to dig into it so that the earth material enters the dipper. The cylinders 72a and 72b are positioned between the gantry 6 and boom 15 30 to brace the boom from movement toward the frame and apply force opposing the force on the dipper from the earth material in the direction of the boom as the dipper moves into the earth material. The boom is thus held firmly by the cylinders 72a and 72b so that it will not 20 pivot or "jack" backward due to force on the dipper opposing the crowd movement.

The hydraulic supply system 11 includes at least one pump such as pump 80 for supplying hydraulic fluid to the hydraulic cylinders 64, 66a, 66b, 72a and 72b for their operation. The hydraulic supply system 11 includes hoses d and piping 92 and 94, shown schetatically in FIG. 2, from the pump to the cylinders 64, 64b, 66a, 66b, 72a and 72b.

The system 11 also includes valves, filters, additional I -3 I' 9 Pg. 1 -9piping, at least one fluid reservoir, and other devices required to supply pressurized hydraulic fluid, which are well-known in the art and are not shown in the drawings.

In the operation of the shovel, with reference to FIG. 2, the drum 50 is rotated to pay out the hoist ropes 52 so that the dipper 44 rotates and drops with the handle 36 about the boom. In conjunction with the paying out of the ropes 52 to permit the dipper to drop, the pistons 74a and 74b are retracted into the crowd 01 .1O cylinders 72a and 72b so that the'handle 36 and dipper 44 are in the position a shown in phantom lines in FIG. 2.

S The drum 50 may then be rotated to take in the ropes 52 so that the dipper 44 moves along a path from position a into engagement with the earth material 90 at position b t15 of the dipper. At the same time, the hydraulic pitch cylinders 66a and 66b may be operated to adjust the Sattitude of the dipper so that the dipper teeth 126 engage the earth material at the desired angular position, in a horizontal position. The crowd t 20 cylinders 72a and 72b are then operated to move pistons 74a and 74b outward so that the boom 30 pivots away from the frame 2. Thereby the handle 36 and dipper 44 also move away from the frame 2 and the dipper co cinues movement along the path from position b into the earth material to position c shown in phantom lines in FIG. 2 so that the earth material 90 enters into the dipper.

Si| During the crowd movement of the dipper by the boom, the handle may be held stationary relative to the boomri 10 However, if desired, the drum 50 may be further rotated to take in the-ropes 52 and pivot the handle and thereby the dipper 44 about te boom simultaneously with the operation of the crowd cylinders to increase the force of the dipper digging into the earth material.

The upper section 37 and lower section 39 of the handle together have a length greater than 'that of the boom 30. Thus, substantial leverage is possible through the length of the handle from the hoist attachment 10 location at handle end 38 to the dipper at handle end Also, the handle can be designed with a length that i."i provides, with the hoist, a selected dipper digging force. During the crowd movement of the dipper and also during the handle pivoting movement of the dipper into 15 the earth material 90, the resisting force of the earth material against the dipper will push against the dipper and handle and thereby the boom to attempt to pivot the boom or "jack" it toward the frame 2. However, the force n j' of the crowd cylinders 72a and 72b in a direction 20 opposing jacking movement of the boom toward the frame and the bracing of the crowd cylinder against the frame will prevent the boom from such movement.

After sufficient earth material enters the dipper 44, the drum 50 is further rotated to pivot the handle about the boom an the hydraulic pitch cylinders 64a and 64b are further operated to tilt the dipper upward to retain the earth material in the dipper as it is lifted by the rotation of the drum and pivoting of the handle to

L

V

/2 i ij i ii .ii g

B

11 tt Vf C t f C 1' IS -e C 4.

position d shown in phantom lines in FIG. 2. The dipper is then lifted further to position e where the revolving frame 2 then may be swung on the crawler frame 12 by operation of the swing motors and drive gears 22 to move the boom, handle and shovel to a dumping location where the hydraulic cylinders 64a and 64b are operated to open the dipper and cause the earth material to be dropped from the dipper.

An alternate embodiment of the invention incorporated in a surface mining shovel shown in FIG. 3.

In the embodiment of FIG. 3, the components of the shovel which operate in the same way as the components shown in FIG. 2 carry the same identifying numerals. Components of the shovel in FIG. 3 which differ in operation from those in FIG. 2 are identified with different numerals.

In FIG. 3, a gantry 100 has an aft leg 102 affixed to the base 4 of the frame 2, and front legs 104 and 106 affixed to a support 108 adjacent to the front end 34 of the base 4. A boom 110 is pivotally mounted by pins 112 on the base 4 adjacent to the end 34 and is also pivotally connected by pins 114 to the handle 36 intermediate the opposite ends 38 and 40 of the handle. A pair of crowd cylinders 116a and 116b are pivotally mounted on the head 118 of the gantry 100 and include pistons 120a and 120b 25 pivotally mounted by pins 122 to the boom 110 adjacent and end 124 of the boom. The hydraulic crowd cylinders 116a and 116b and their pistons 120a and 120b operate in substantially the same manner as the hydraulic crowd i f -12 12 cylinders 72a and 72b and their pistons 74a and 74b shown in FIG. 2. Thus, the hoist 46 and crowd cylinders 116a and 116b cooperate to move the dipper 44 to positions a and b, as shown in FIG. 3. The crowd cylinders 116a and 116b extend the pistons 120a and 120b to pivot the boom 110 away from the frame 2 to thereby move the dipper 44 into the earth material 90 and the hoist 46 pivots the handle and dipper to positions d and e prior to dumping the earth material from the dipper.

19 The reacting force of naterial 90 against the dipper 44 attempts to jack the boom 110 about the pins 112 L toward the frame 2 during digging of the dipper into the earth material. However, the force of the cylinders 116a and 116b in the direction of the reactive force caused by the material 90 resists and prevents the jacking movement of the boom 110. The connection of the pistons 120a and t C'i 120b adjacent the end 124 of the boom, at a location relatively close to the pivot pins 42 at which the handle is mounted on the boom, decreases the amount of bending stress on the boom 110 as compared to the amount of the stress on the boom 30 in the embodiment of the invention illustrated in FIG. 2. Also, the attachment of the gantry 100 adjacent the end 34 of the base 4 simplifies the machinery house structure because the gantry does not project through the machinery house. Further, positioning the gantry at the working end 34 of the base permits shorter length crowd cylinders 116a and 116b.

This results in relatively greater rigidity of the crowd i 13 13 and boom structure, particularly when the crowd pistons are extended, and permits a lower volume and lower pressure hydraulic fluid system.

The invention described herein provides a highly effective apparatus and method for preventing boom jacking of a surface mining shovel. The crowd mechanism is further arranged to provide a particularly high level of crowd force. The crowd mechanism according to the S invention eliminates the common prior art rack and pinion Sre 10 crowd mechanism and, as a consequence, permits hydraulic fluid connections between the machinery house of the tB shovel and the handle so that hydraulic pitch adjustment is available for the dipper of the shovel. The invention also includes a wire rope hoist arrangement in which the t 15 rope is attached directly to an end of the handle to provide a lcng lever arm and high digging and lifting force for the dipper. The durability of the hoist ropes I is enhanced by the elimination of boom jacking by the crowd mechanism to thereby correspondingly eliminate hoist rope shock due to the jacking movement.

It will be understood that the foregoing description of the present invention is for purposes of illustration only and that the invention is susceptible to a number of modifications or changes, none of which entail any departure from the spirit and scope of the present invention as defined in the hereto appended claims.

f

__J

Claims

1. A surface mining shovel for digging into and moving earth material, the shovel having a frame including a working end, comprising: a gantry support extending upward from the frame; a boom extending upward from and pivotally mounted on the frame at a location adjacent the working end of the frame; a handle mounted on the boom for pivotal movement relative thereto about an axis; a dipper mounted on the handle and engageable with the earth material as the handle pivots; hoist means for pivoting the handle to engage the dipper with the earth material and lift the dipper; and crowd means connected to the boom and to the gantry support, the connection of the crowd means to the boom being at a location spaced from said axis, the connection of the crowd means to the gantry- support being at a position above the location at which the boom is mounted on the frame, for pivoting the boom and moving the .1 dipper on the handle into the earth material whereby the earth material enters the dipper and can be lifted with the dipper as the handle is pivoted by the hoist means.

2. The shovel according to claim 1 wherein the crowd means comprises a hydraulic cylinder containing hydraulic fluid and connected to the gantry support at said position and a piston connected to the boom, the 30 piston being movable outward from the cylinder toward the boom in response to movement of hydraulic fluid in the 0. cylinder whereby crowd force is applied to the boom.

3. The shovel according to claim 1 wherein the crowd means comprises a hydraulic crowd means including a 35 cylinder and a piston movable outward from the cylinder for providing force to move the handle and dipper away from the frame, the movement of the dipper by the crowd 3c I 0 means during said force and movement provided by the piston being only along a path away from the frame.

4. A surface mining shovel for digging and moving earth material, the shovel having a frame including a working end, comprising; a boom extending upward from the frame and having upper and lower ends, the lower end of the boom being mounted at a location on the frame adjacent the working end of the frame, dipper means for digging into and carrying the earth material; an elongated handle having first and second opposite ends, the handle being mounted for pivotal movement on the upper end of the boom at a pivot point Intermediate the opposite ends of the handle, the dipper means being mounted on the second end of the handle and pivotally movable with the handle along a path into the earth material; hoist means connected to the handle adjacent the first end of the handle for pivoting the handle and the dipper about the pivot point on the boom along said I path of the dipper into the earth material; and crowd means connected to the boom and to the It frame, the crowd means being connected to the boom at a t l point spaced from said pivot point, the crowd means being i t C connected to the frame at a position above the boom for i moving the handle and the dipper on the handle along said path into the earth material, the movement by the crowd means of the handle and the dipper being simultaneous with 30 the pivotal movement of the handle to move the dipper along the path into the earth material, whereby the movement of the handle due to both the crowd means and hoist means provides a high dipper digging force into the earth material. S.a 35 5. The shovel according to claim 4 wherein: i the hoist means includes a rotatable .drum mounted ofl the frame and a rope connected to the handle L i 16 and windable on to and off the drum for providing force to pivot the handle and move the dipper along said path into the earth material; and the crowd means comprises hydraulic cylinder and piston means connected to the boom for providing hydraulic digging force to move the handle and the dipper along said path into the earth material simultaneously with the providing of digging force by the rope whereby high digging force is provided by the hydraulic means and rope of the hoist means together.

6. A method of digging into earth material with a surface mining shovel having a frame, a boom pivotally mounted on and extending upwardly from the frame, an elongated handle pivotally mounted on the boom, a dipper affixed to an end of the handle, and crowd means connected to the boom and the frame, comprising the steps of: pivoting the handle on, the boom to move the dipper into engagement with the earth material; and applying force from a position above the pivotal mounting of the boom on the frame directly to the boom, at a point spaced from the pivotal connection of the handle and the boom, with the crowd means in a digging direction to move the handle and thereby the dipper to dig into the earth material.

7. The method according to claim 6 further comprising the step of pivoting the handle to move the dipper to dig into the earth material simultaneously with the applying of force to the boom with the crowd means to 30 move the dipper to dig into the earth material. :e 8. The method according to claim 6 or 7 e wherein: the step of applying force with the crowd means comprises applying hydraulic force to a hydraulic piston within a cylinder and connected to the boom to move v i the piston irn a direction outward from the cylinder; and 1/ 17 the step of pivoting the handle includes providing a rotatable drum and a rope connected to the handle and the drum, and rotating the drum to wind the rope onto or pay rope off of the drum to pivot the handle upward when the drum winds rope onto the drum and pivot the handle downward when the drum pays rope off of the drum and the weight of the handle moves the handle downward.

9. The method according to claim 6 or 7, wherein: the frame includes an upwardly extending gantry support; and further comprising the step of bracing the crowd means against the gantry support while simultaneously applying force to the boom with the crowd means. A surface mining shovel for digging into and moving earth material, the shovel comprising: a frame including a working end; a boom extending upward from and pivotally mounted on the frame at a location adjacent the working end of the frame; a handle mounted on the boom for pivotal 'L.t ,movement relative thereto about an axis; a dipper mounted on the handle and engageable 25 with the earth material as the handle pivots; a hoist mechanism for pivoting the handle to engage the dipper with the earth material and lift the *dipper; and a crowd mechanism connected to the boom and to 30 the frame, the crowd mechanism being connected to the boom at a first point spaced from said axis, the crowd mechanism being connected to the frame at a second point, and the crowd mechanism being operable to force the first point away from the second point so as to force the dipper 35 into the earth material. l11. A shovel as set forth in claim 10 wherein .r the second point is above the first point. 18

12. A shovel as set forth in claim 10 wherein the second point is above the pivotal connection of the boom to the frame.

13. A shovel as set forth in claim 10 and further, comprising a gantry support extending upwardly from the frame, and wherein the crowd mechanism is connected to the frame via the gantry support.

14. A shovel as set forth in claim 10 wherein the crowd mechanism includes an extendible and contractible hydraulic device, and wherein the first point is forced away from the second point by extending the hydraulic device. A shovel as set forth in claim 10 wherein tne handle has upper and lower ends, wherein the dipper is mounted on the handle adjacent the lower end thereof, wherein the hoist mechanism is connected 'to the handle adjacent the upper end thereof, and wherein the boom is pivotally connected ,to the handle intermediate the upper and lower ends thereof.

16. A shovel as set forth in claim 10 wherein the hoist mechanism includes a rotatable drum mounted on the frame and a rope connected to the handle and windable on to and off of the drum. $fi 17. A shovel as set forth in claim 10 wherein 25 the boom has a lower end mounted on the frame and has an upper end on which the handle is mounted. S 18. A shovel as set forth in claim 10 wherein 0 the crowd mechanism is connected to the boom between the frame and said axis. 30 19. A shovel as set forth in claim 1 wherein the boom has a lower end mounted on the frame and has an upper end on which the handle is mounted. A shovel as set forth in claim 1 wherein the crowd means is connected to the boom between the frame 35 and said axis.

21. A surface mining shovel for digging into and moving earth material, the shovel comprising: pFLI.s~ O~jI C.^ 19 a frame including a working end; a gantry support extending upwardly from the frame; a boom extending upward from the frame and having upper and lower ends, the lower end of the boom being pivotally mounted on the frame at a location adjacent the working end of the frame; a handle mounted on the upper end of the boom for pivotal movement relative thereto about an axis, the handle having upper and lower ends, the handle being pivotally connected to the boom at a point intermediate the upper and lower ends of the handle; a dipper mounted on the handle adjacent the lower end thereof and engagable with the earth material as the handle pivots; a hoist mechanism for pivoting the handle to engage the dipper with the earth material and lift the dipper, the hoist mechanism including a rotatable drum mounted on the frame and a rope connected to the handle adjacent the upper end thereof and windable on to and off of the drum; and a crowd mechanism connected to the boom and to the gantry support, the crowd mechanism being connected to let:, the boom at a first point spaced from the axis, the crowd mechanism being connected to the gantry support at a ,4 second point, the second point being above the first point S :4 and above the pivotal connection of the boom to the frame, the crowd mechanism including an extendible and cntractible hydraulic device, and the crowd mechanism i 30 being operable to force the first point away from the 'second 'point by extending the hydraulic device so as to force the dipper into the earth material. 00

22. A surface mining shovel for digging into and moving earth material, the shovel being substantially as hereinbefore described with reference to the accompanying drawings.

23. A method for digging into earth material with a surface mining shovel, said method being substantially as hereinbefore described with reference to the accompanying drawings. DATED this Twenty-eighth Day of April 1995 Harnischfeger Corporation Patent Attorneys for the Applicant SPRUSON FERGUSON (I( (ta 1 1 I I I I I II ii. 6 St I I II I f I 'ftl 11 *i II I 41 4I IN\ibt)0529:HIW