US3375892A - Stepping-type propulsion means for excavators - Google Patents

Stepping-type propulsion means for excavators Download PDF

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Publication number
US3375892A
US3375892A US506207A US50620765A US3375892A US 3375892 A US3375892 A US 3375892A US 506207 A US506207 A US 506207A US 50620765 A US50620765 A US 50620765A US 3375892 A US3375892 A US 3375892A
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United States
Prior art keywords
shoe
cylinder
pumps
frame
machine
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Expired - Lifetime
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US506207A
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English (en)
Inventor
Melvin W Kraschnewski
Learmont Tom
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Caterpillar Global Mining LLC
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Bucyrus Erie Co
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Application filed by Bucyrus Erie Co filed Critical Bucyrus Erie Co
Priority to US506207A priority Critical patent/US3375892A/en
Priority to DE1966R0044495 priority patent/DE1634958B2/de
Priority to GB48886/66A priority patent/GB1154523A/en
Application granted granted Critical
Publication of US3375892A publication Critical patent/US3375892A/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D57/00—Vehicles characterised by having other propulsion or other ground- engaging means than wheels or endless track, alone or in addition to wheels or endless track
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
    • E02F9/02—Travelling-gear, e.g. associated with slewing gears
    • E02F9/04—Walking gears moving the dredger forward step-by-step

Definitions

  • a walking dragline has a central tub, a revolving frame, and a pair'of shoeson opposite sides which are movable vertically and horizontally to provide a stepping-type propulsion.
  • a pair of hydrauliclift cylinders on the frame have ball and socket connections with slides which are received in slideways on theshoes, the lift cylinders thus being adaptedto effect verticalmovement of the shoes.
  • hydraulic push cylinder is connected between each shoe and slide toeflect horizontal movement.
  • the ball and socket connections aresubstantially the only connections between the shoes and the frame so that the shoes are capable ofthree degrees of movement during walking.
  • shoes are urged toward a parallel relationship with the frame by meansof ropes leading from the ends of'the shoes to a sheave on the frame which is held against rotationby means of a hydraulic cylinder.
  • the shoes are also aligned with respect to the frame by means of rollers on the frame that engage the upper surface of the shoes 9 at laterally and longitudinally spaced points.
  • a plurality of pumps operate the cylinders, and these are divided into two sets. All ofthe pumps drive the lift cylinder when the machineis being lifted and all of the pumps drive thepush cylinderwhenthe machine is being moved, but one set of pumps drives thelift cylinder andthe other set of pumps simultaneously drivesthe push cylinder during a portion of the return movement of the shoe.
  • Thisinvention relatesto stepping-type propulsion means for excavators, and resides more specifically in a hydraulic propulsion system particularly suitable for extremely large excavating machines.
  • the particular propulsion system shown herein has been designed for a dragline having a bucketcapacity of 150 cubic yards, a working weight of some 14 million pounds, overall width and body length of 116 and 115 feet, respectively, and two walking shoes each of which is 78 feet long and 15 feet wide and 'weighs about 400,000 pounds
  • known prior art propulsion systems simply do not allow for sufiicient mechanical strength to withstand the stresses and forces encountered in moving a machine of these gigantic proportions.
  • his a furtherobject of the invention to provide a propulsion system utilizing a particularly advantageous cycle of operation for extremelylarge and heavy machines.
  • FIG. 1 is a side view in elevation showing a walking dragline incorporating apropulsion system formed according to this invention.
  • FIG. 2 is an enlarged fragmentary view with parts 3 shown broken away and in cross section, taken through the plane 22 shown in F IG. 4,
  • FIG. 3 is an enlarged fragmentary view, with parts shown broken away and in cross section, taken through the plane 33 shown in F IG. 2,
  • FIG. 4 is an enlarged fragmentary view, with parts shown broken away and in cross section, taken through the plane 4-4 shown in FIG. 3,
  • FIGS. through comprise a series of fragmentary schematic views illustrating the walking operation of the dragline of FIG. 1, and
  • FIG. 11 is a schematic diagram of a hydraulic circuit for the propulsion system of FIG. 1.
  • the dragline shown therein includes a main frame or body 1 that includes a circular tub 2 on which the major portion of the frame 1 is rotatably supported.
  • a boom 3 has its inner end pivotally supported on the frame 1 and its outer end supported from an A-frame 4 and an auxiliary mast 5 by means of pendants 6 and an auxiliary cable arrangement 7.
  • a hoist rope 8 leading from a winch mechanism (not shown) on the frame 1 passes about the end of the boom 3 and is connected to a drag bucket 9.
  • a drag rope 10 is connected between the bucket 9 and a second winch mechanism (not shown) on the frame 1.
  • a pair of shoes 12 are disposed on opposite sides of the frame 1 and are actuated in stepping fashion as will be described to move the machine forwardly, to the left as seen in FIG. 1.
  • the shoes 12 and the other noted elements are all connected to the frame 1 above the tub 2, so that they can turn with respect to the tub 2 so that the direction of movement of the machine can be changed. Only one shoe 12, together with a set of associated elements that will be described, has been shown in the drawings and will be described below. It will be understood, however, that the same arrangement is used on both sides of the machine is accordance with usual practice.
  • a lateral extension 13 of the frame 1 overhangs the shoe 12.
  • a conventional double acting hydraulic lift cylinder 14, which may be of any suitable design, is rigidly mounted on the frame extension 13 with its extensible rod 15 directed downwardly toward the shoe 12.
  • the bottom surface of the rod 15 is hollowed out to define a hemispherical re- 7 cess 16, and a split retaining collar 17 of any suitable configuration is removably attached to the lower end of the rod 15 in alignment with the recess 16.
  • the collar 17 and recess 16 together form a spherical socket which receives and holds captive the ball head 18 of a slide 19.
  • the bottom surface of the slide 19 is flat and is provided with opposite, parallel laterally extending flanges 20.
  • a pair of generally parallel, L-shaped guides 22 are fixed to the upper surface of the shoe 12 in overhanging relationship to the flanges 20.
  • the guides 22 thus establish a slideway providing for relative horizontal movement between the shoe 12 on the one hand and the cylinder 14, and frame, 1 on the other.
  • the guides 22 are made to converge slightly from left to right as seen in FIG. 3 to provide a centering action as the shoe 12 moves to the left as seen in FIG. 3. Since the shoe 12 is, in effect, connected to the frame 1 only through the ball and socket or universal connection, it has limited freedom of movement in three planes.
  • a conventional double acting hydraulic push cylinder 23 is mounted atop the shoe 12 and connected between the shoe 12 and the slide 19. The outer end of the rod 24 of the cylinder 23,
  • a vertical pin 26 extends through these elements and establishes a pivotal connection between the rod end of the cylinder 23 and the shoe 12.
  • the blank or piston end of the cylinder 23 is provided with an apertured mounting ear 27 which is received in an apertured, bifurcated bracket 28 formed integrally with the slide 19.
  • a vertical pin 29 passes through these elements and, there fore, establishes a pivotal connection between the piston end of the cylinder 23 and the slide 19.
  • a front roller support 30, which is a rigid lateral extension of the frame 1, overhangs the shoe 12 forwardly, to the left as seen in FIG. 3, of the guides 22 and serves to rotatably support a front roller 32 that is engageable with the upper surface of the shoe 12.
  • a rear roller support 33 extends laterally from the frame 1 and rotatably supports a rear roller 34 engageable with the upper surface of the shoe 12 rearwardly, to the right as seen in FIG. 3, of the guides 22.
  • the rear roller 34 is spaced inwardly with respect to the forward roller 32.
  • the rollers 32 and 34 serve to level and align the shoe 12 during walking as will be described.
  • Bracket .35 Extending laterally from the frame 1, approximately midway between the roller supports 30, 33, is a bracket .35 which rotatably supports a honizontally disposed sheave 36.
  • a constant pressure hydraulic cylinder 37 is mounted and operable between the frame 1 and the sheave 36 to hold the latter against rotation in either direction.
  • a pair of bifurcated brackets 38 are mounted on and extend outwardly from the frame 1 on opposite sides of the bracket 35 and the roller supports 30, 33.
  • a pair of horizontally disposed, double sheave blocks 39 are pivotally mounted on the brackets 38 and are pivotal in vertical planes generally transverse to the length of the frame 1.
  • a pair of ropes have their inner ends anchored to the sheave 36 at approximately diametrically opposite points and thence extend through respective sheave blocks 39 and are anchored, respectively, near the front and rear ends of the shoe 12.
  • the ropes 40 and their associated elements tend to keep the shoe 12 substantially parallel to the frame 1 since any tendency of the shoe 12 to rotate in a horizontal plane either clockwise or counterclockwise as seen in FIG. 3 will be resisted by the constant force exerted by the cylinder 37 on the sheave 36.
  • the use of the double sheave blocks 39 which are pivotally mounted compensates for vertical and horizontal movement of the shoe 12 with respect to the frame 1, thus insuring aligning action regardless of the position of the shoe 12 with respect to the frame 1.
  • FIG. 11 shows, schematically, a hydraulic circuit for the lift cylinder 14 and push cylinder 23. Again, the circuit shown is only for the cylinders 14, 23 on one side-v of the machine, and there will be an identical arrangement for the other side of the machine.
  • the circuit includes five conventional electric induction motors, M M Each of the motors M M drives two hydraulic pumps, there being ten pumps, numbered P P in all.
  • the pumps P 4 are all of the reversible, variable delivery type. As a result, they have three positions: a right position in which flow is directed upwardly as seen in FIG. 11, a left position in which flow the valve 42 to the blank or piston end of'the lift cylinder '14,and iscontrolled by a conventionalvalve 44.
  • a secondmain line leads from the other outlet of the valve 42 to the rod end of the cylinder 14 and is controlled by a valve.
  • the valve 42 has a centered, closed position, a left position in whichtheline 45 isconnected to the reservoir and a right position in which the line 43-is connected to the reservoir.
  • a prefillline 47 leadsfrom the piston end of the cylinder 14'to the reservoir and is controlled by a prefill valve 48 whichis inturn controlled'by a minimum pressure switch 49 that is adapted to sense thepressure in the rod end of the cylinder 14.Two additional pressure switches 50 and 52 are adaptedto sense thepressure in the piston end of the cylinder 14 for purposes that willbe described.
  • the first four pumps, P -P form a set and are arranged in two groupsof two, each groupbeing connected acrossthc lines 43 and 45.
  • the remaining six pumps, P P are connected in parallel to form a set of pumps designated generally bythe reference numeral "53.
  • the set 53 is connected to the line 43'by aline 54 and is connected to the line 45 by a line 55 which is controlled by avalve 56.
  • a set of three crisscrossvalves57 is provided,eachof which has two inlet openings and two outlet openings.
  • Thevalves'57 have center, closed positions, right positions providing straight through connections and left positions providing crisscross connections.
  • a set of three lines-58 connect the pump set 53 to one of the inlets of each valve 57.
  • Abranchedline 59 connects the opposite outlet of each valve 57 to the blank or piston end of the push cylinder 23.
  • a secondbranched line 60 leads from the rod end of the cylinder 23 to the other outlets of the valves'57.
  • the other inlets of the valves 57 are'connected to the reservoir by lines62.
  • a pair of lines'63 are connected across the lines 45 and 59 and are controlled by a pair of valves 64.
  • a line branches from the line 59 near the piston end of the cylinder'23 tothe reservoir and is controlled by a valve 66.
  • a line leads from the rod end of the cylinder 23 to the reservoir and is controlled by a check valve71 which allows flow from but not to the reservoir.
  • the dragline is shown in its normal working position. That is, the tub 2 is resting on the ground and the shoes 12 are raised off the ground and are in a forward position, to the left as seen in FIG. 1, with respect'to the frame 1.
  • Fluid from therod end of the cylinder14 will flow through the valve 46 and lines 45 and 55 to the left,lower, sides of the pumps P P Assuming all the lines to befull of fluid, there is a brief period during the lowering of the shoe 12 inwhich .the pumps P P areactually pumpingfluidto the piston end of the cylinder 14. Almost immediately, however, thetremendous weight of the shoe 12, approximately 600,-
  • the primaryforce acting to lower the shoe l2 is a gravity force.
  • the motors M -M are induction motors and at the outset of a loweringaction are operatingto drive the pumps P P
  • the fluid forced intothepumps bythe weight ofthe shoe12 begins to take over as the drivingforceforthe pumpsP P so that they are in effect being driven by the released mechanic-al energy of the shoe 12.
  • the'motors M M M reach synchronous speed, beyond which they cannot be speeded up and still act as motors, they begin to act as generators so thatfurther mechanical energy supplied'by the dropping shoe 12 is converted to electrical energy. This energy is absorbedin the electrical system ofthe machine which, of course, encompasses many elements other than the propulsion system.
  • Raising of the machine involves afurther extension of the cylinder14. Since the shoe 12 is on the ground,such furtherextension will cause the frame 1 to be raised.'Raising is accomplished by moving the valve 42 to its left position wherein the line '45 is connected to the reservoir. The pumps P -P whichremainedin'full right position at the conclusion of the shoelowering phase, continue to pump upwardly, and the valves 44, 46, and 56 remain open. Thus, fluid. under pressure isforced by allten pumps P -P through the line 43 into the piston end of the cylinder 14 resulting infurther extensionof'the rod 15 until the machine reaches the position ofl- IG. 6.
  • the cylinders 14 are located forwardly, to the left as seenin FIG.6, ofthe center of gravity of'the machine so that this lifting will cause the machine to be tilted to raise its forward or left hand edge off the ground while its rear or righthand edge remainsvon the ground.
  • the balland 12 and frame 1 alof movement afforded by the universal ball andsocket connection becomes important, "Any ground irregularities or differences in elevation will tend to causethe shoe 12 to twist as the frame 1 is raised.
  • the ball and socket connection gives the shoe 12 freedom of movement in three degrees, however, so that such twisting is not transmitted to the frame 1.
  • the ball and socket arrangement is advantageous in that it provides the required freedom while still allowing for suflicient mechanical strength and bearing area.
  • the push cylinder 23 is connected below the ball and socket connection. It is thus free to move in all planes with the shoe 12 without necessitating the provision of universal connections for its ends.
  • Raising of the machine continues until the machine has been raised to a desired height and until it is fully supported by the shoe 12 and cylinder 14.
  • the fact that the machine is being supported is reflected in terms of pressure in the piston end of the cylinder 14, and the required pressure is sensed by the pressure switch 50, which is set to operate at a preselected pressure of about 1700 p.s.i. Requiring a certain pressure to be developed before the next step of walking is accomplished ensures against the possibility of the machine being moved when, for example, one shoe 12 is in soft ground and is not supporting the machine.
  • a limit switch (not shown) is provided, which is closed only when the rod 15 has been extended a preselected distance.
  • the push cylinder 23 is extended and serves in effect to propel the frame 1 to the left or forwardly with respect to the shoe 12 to the position of FIG. 7. Since the valves 44 and 46 are closed, the cylinder 14 remains in its extended position.
  • the valve 42 is shifted to its right position connecting the line 43 with the reservoir.
  • the valves 64 are opened, and the valves 57 are shifted to their right positions connecting the line 60 to the lines 62 and the lines 58 to the line 59.
  • the pumps P P are moved to full left position wherein they are pumping downwardly as seen in FIG. 3. All ten pumps, P P are then delivering fluid under pressure to the line 59 and into the piston end of the cylinder 23.
  • Fluid for the pumps P P is supplied from the reservoir through the valve 42 and line 43. Fluid forced out of the rod end of the cylinder 23 passes through the line 60, the valves 57 and the lines 62 into the reservoir.
  • a limit switch (not shown) senses full extension of the cylinder 23 and returns the pumps P P to center and closes the valves 42, 57 and 64.
  • the pressure switch 52 which is a minimum pressure switch set to close at an appropriate low pressure. When the switch 52 closes, the pumps P P are returned to center, and the valves 42, 44 and 56 are closed.
  • Fluid under pressure is then directed downwardly through the four left hand pumps, P P through the line 45 and valve 46 to the rod end of the cylinder 14 causing it to be retracted to lift the shoe 12 upwardly.
  • Fluid forced out of the piston end of the cylinders 14 passes through the valve 48 and into the reservoir.
  • Fluid for the pumps P P is supplied from the reservoir through the valve 42 and line 43.
  • the fact that the shoe 12 has been raised to its intermediate position is sensed by an intermediate limit switch (not shown).
  • the set 53 of six pumps P -P causes fluid to be pumped downwardly through the lines 58 through the valves 57 to the line 60 and into the rod end of the cylinder 23 causing it to be retracted to slide the shoes 12 to the left from the position of FIG. 9 through the position of FIG. 10 back to the position of FIG. 1.
  • the fluid for the pumps P P is also supplied from the reservoir through the valve 42 and line 43.
  • the check valve 71 allows fluid to flow directly from the reservoir to the rod end of the cylinder 23 to avoid drawing a vacuum. Fluid expelled from the piston end of the cylinder 23 passes through the line 59 and 65 and valve 66 into the reservoir.
  • valve 71 which is always open to allow flow from the reservoir
  • valve 68 which is opened.
  • the valve 68 and relief valve 69 serve as a cushion for releasing the kinetic energy of the shoe 12 if a walking cycle is completed while the machine is going downhill, in which case there would be a tendency for the shoe 12 to keep moving.
  • the pressure developed in the piston end of the cylinder 23 as the result of such movement is relieved through the valves 68 and 69, the valve 69 being set to provide deceleration to zero within an inch or two of movement.
  • the valve 71 admits fluid to prevent drawing a vacuum in the rod end of the cylinder 23 during such movement.
  • an auxiliary, pressure-compensated pump (not shown) of any suitable type can be connected to the rod ends of the cylinders 14 and 23 to maintain a holding pressure. If desired, the same pump could be used to operate the cyilnder 37. During working, it is best to have the push cylinder 23 fully retracted or bottomed. To accomplish this, the valve can be closed after a suitable time delay allowing for deceleration, andthe valve 66 openedfThe auxiliary pump will then be ableto move the cylinder 23 gradually tofully retracted position.
  • rollers 32 and 34 contact the upper surface of the shoe12 to align it in a vertical plane generally'parallel to its direction of movement.
  • roller 32 is placed approximately on the longitudinal centerline of the shoe 12 where his in alignment with the center of gravity of theshoe 12, which is also on the centerline.
  • the roller 34 is spaced inwardly from the roller 32 so that when the shoe 12 is in the position of "FIG. 1 it is held in a predetermined position of alignment against rotation about itslongitudinal axis. Since theroller 32 is on the centerline of the shoe 12'and in alignment with its center of gravity,however, it would be possible for the shoe 12to rock slightly in a clockwise direction as seen in FIG. 4 during working. To guard against this,the roller 34 is preferably set slightly lower than the roller 32 to cause slight clockwise tilting of the shoe 12. When it is slightly out of equilibrium in this fashion, the shoe 12 tends to rotate in a counterclockwise direction and is thus held tight against the roller 34.
  • the ropes 40 and their associated elements serve to align the shoe 12 so that it is moved into 'a positionparallel to the frame 1 as it is being raised and moved in preparation for a succeeding walking step. This function is aided 'by the tapered guides 22.
  • the ropes 40 are primarily operable when the shoe 12 is being moved in preparation for another step and are not of sufiicient strength to align the shoe 12 as the machine is being moved. That is, any ground irregularities which would tend to cause the shoe.12 to be twisted as the machineis being walked generate forces far greater than those which the cylinder 37 is capable of absorbing so that it will simply be overridden.
  • rollers 32 and34, ropes 40 and tapered guides 22 I thus provide relatively simple means for aligning and leveling the shoe 12 in all planes, to insure that the shoe 12 will be properly aligned for succeeding steps.
  • P -P is very advantageous in that it allows all ten pumps to be used for raising and propelling the frame 1, when the load is greatest, and when the energy released as a result of lowering the frame 1 or the shoe 12 is to be absorbed.
  • the pumps are broken into the two sets for raising and moving the shoe 12, however, since the load is thenless and so that these steps canbe effected simultaneously with a considerable saving of time.
  • thelines 58 and-59 connect the pump set 53 to the pistonend ofthe cylinder 23, while thelines 63 leadfrom the connectionsof the pumps P -P totheline 45tothe line 59 to connect these pumps to the piston end of the cylinder 23.
  • thelines 58 and60herein connecting the other set of pumps, theset 53 herein, to the other end ofthe push cylinder 23.
  • stepping-type propulsionxmeans for an excavator having a frame/the combination comprising: a vertical hydraulic lift cylinder mounted on the frame; a slide; a universal connection between the slide and the lift cylinder; a shoe; a slideway on the shoe that receives the slide, the shoe thus being mounted for vertical movement with respect to the frame in response to the lift cylinder and for horizontal movement with respect to the frame; a horizontal hydraulic push cylinder connected and operable between the shoe and the slide to effect horizontal 1 1 movement of the shoe with respect to the frame; and a pair of rollers supported from the frame that are engageable with the upper surface of the shoe at laterally and longitudinally spaced points to align the shoe with respect to the frame in vertical planes parallel and transverse to the length of the shoe.
  • Propulsion means including a plurality of pumps divided into two sets of at least one each, connections between the pumps and the lift and push cylinders, and a control circuit to establish a cycle of operation having at least three phases, in one of which all of the pumps drive the lift cylinder in one direction, in another of which all of the pumps drive the push cylinder in one direction, and in the other of which one set of pumps drives the lift cylinder in the other direction while the other set of pumps drives the push cylinder in the other direction.
  • stepping-type propulsion means for an excavator having a frame
  • the combination comprising: a vertical hydraulic lift cylinder mounted on the frame; a slide; a universal connection between the slide and the lift cylinder; a shoe; a slideway on the shoe that receives the slide, the shoe thus being mounted for vertical movement with respect to the frame in response to the lift cylinder and for horizontal movement with respect to the frame; a horizontal hydraulic push cylinder connected and operable between the shoe and the slide to effect horizontal movement of the shoe with respect to the frame; a rotatable sheave supported from the frame near the lift cylinder; means to exert a constant force resisting rotation of said sheave in either direction; and a pair of rope means anchored to said sheave and to opposite ends of the shoe, the shoe thereby being urged toward parallel relationship with the frame.
  • Propulsion means according to claim 3 wherein the universal connection is a ball and socket connection and the push cylinder is connected to the slide below the ball and socket connection, the shoe and push cylinder thus having limited freedom of movement with respect to the frame in three planes; and including a pair of rollers supported from the frame that are engageable with the upper surface of the shoe at laterally and longitudinally spaced points to align the shoe with respect to the frame in vertical planes parallel and transverse to the length of the shoe.
  • An operating and control circuit for stepping-type propulsion means for an excavator having a frame said propulsion means including a shoe, a hydraulic lift cylinder to effect relative vertical movement between the shoe and the frame, and a hydraulic push cylinder to effect relative horizontal movement between the shoe and the frame, said circuit including: a plurality of pumps divided into two sets of at least one each; and connections between the pumps and cylinders whereby all of the pumps can be connected to drive one cylinder in one direction,
  • all of the pumps can be connected to drive the other cylinder in one direction, and one set can be connected to drive one cylinder in its other direction while the other set is connected to drive the other cylinder in its other direction.
  • connections include means to connect both sets of pumps to the top end of the lift cylinder, means to connect both sets of pumps to one end of the push cylinder, and means to effect a simultaneous connection between one set of pumps and the bottom end of the lift cylinder and the other set of pumps and the other end of the push cylinder.
  • a circuit according to claim 5 wherein the pumps are reversible and including: a first main line leading from the upper end of the lift cylinder; a second main line leading from the lower end of the lift cylinder, both sets of pumps being connectable across the main lines; a line leading from one end of the push cylinder; a line leading from the other end of the push cylinder; means to connect one set of pumps to the line from one end of the push cylinder; and means to connect the other set of pumps alternatively to both lines leading from the push cylinder.
  • a circuit according to claim 7 wherein there is a cycle of operation in which the lift cylinder is first partially extended to lower the shoe to the ground, the lift cylinder is then further extended to raise the frame, the push cylinder is then extended to move the frame forwardly with respect to the shoe, the lift cylinder is then partially retracted to lower the frame to the ground, the lift cylinder is then further partially retracted to raise the shoe at least partially from the ground, and the lift cylinder is then further retracted to raise the shoe completely off the ground while the push cylinder is simultaneously retracted to move the shoe forwardly with respect to the frame.
  • a circuit according to claim 8 wherein fluid is expelled from the ends of the lift cylinder by the weight, respectively, of the shoe and frame as they are lowered, and the pumps are driven by electric induction motors, and the fluid thus expelled passes through the pumps and raises the speed of the motors to the point where they act as generators.
  • a stepping-type excavator having a central tub adapted to rest on the ground, a revolving frame on the tub, and a single pair of shoes on opposite sides of the excavator which are adapted to be moved horizontally and vertically with respect to the frame and tub to effect a stepping-type propulsion of the excavator

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  • Mining & Mineral Resources (AREA)
  • Civil Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Structural Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Fluid-Pressure Circuits (AREA)
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US506207A 1965-11-03 1965-11-03 Stepping-type propulsion means for excavators Expired - Lifetime US3375892A (en)

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US506207A US3375892A (en) 1965-11-03 1965-11-03 Stepping-type propulsion means for excavators
DE1966R0044495 DE1634958B2 (de) 1965-11-03 1966-10-31 Schreitwerk fuer extrem schwere bagger mit einem auf einer mittelkufe drehbar gelagerten rahmen
GB48886/66A GB1154523A (en) 1965-11-03 1966-11-01 Stepping-Type Propulsion Means for Excavators

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Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3493064A (en) * 1967-12-26 1970-02-03 Bucyrus Erie Co Walking mechanism for dragline excavators and the like
US3500945A (en) * 1968-05-01 1970-03-17 Marion Power Shovel Co Walking mechanism assembly
US3512597A (en) * 1968-01-17 1970-05-19 Marion Power Shovel Co Walking mechanism and control therefor
EP0016390A1 (de) * 1979-03-13 1980-10-01 Edward L. Bateman Limited Schreitwerk
US4252204A (en) * 1979-04-09 1981-02-24 Varian Associates Walking drag line
FR2507984A1 (en) * 1981-06-19 1982-12-24 Komatsu Mfg Co Ltd Laterally movable mobile crane - has double acting hydraulic cylinders to actuate outriggers to lift crane sideways
US4519468A (en) * 1983-03-24 1985-05-28 Fmc Corporation Steerable carrousel supported walking beam vehicle
US20170021880A1 (en) * 2011-12-16 2017-01-26 Entro Industries, Inc. Mounting structure with storable transport system
USRE46723E1 (en) 2011-12-16 2018-02-20 Entro Industries, Inc. Alignment restoration device for load transporting apparatus
US10202156B2 (en) 2014-08-20 2019-02-12 Hydraulic Systems, Inc. Stabilizer frame apparatuses and methods of using same
US10556631B2 (en) 2011-12-16 2020-02-11 Entro Industries, Inc. Low profile roller assembly
US10793409B2 (en) 2017-07-12 2020-10-06 Entro Industries, Inc. Lifting loads with lifting devices
US10889961B2 (en) 2017-08-08 2021-01-12 Entro Industries, Inc. Automatic walking for a load transporting apparatus
US10895882B2 (en) 2017-08-01 2021-01-19 Entro Industries, Inc. Controlling load transporting devices
US10899401B2 (en) 2017-06-05 2021-01-26 Entro Industries, Inc. Yaw alignment system
US11180319B2 (en) 2017-11-22 2021-11-23 Entro Industries, Inc. Skid system for load transport apparatus
US11407460B2 (en) 2018-05-31 2022-08-09 Entro Industries, Inc. Nonlinear walking apparatus
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US3493064A (en) * 1967-12-26 1970-02-03 Bucyrus Erie Co Walking mechanism for dragline excavators and the like
US3512597A (en) * 1968-01-17 1970-05-19 Marion Power Shovel Co Walking mechanism and control therefor
US3500945A (en) * 1968-05-01 1970-03-17 Marion Power Shovel Co Walking mechanism assembly
EP0016390A1 (de) * 1979-03-13 1980-10-01 Edward L. Bateman Limited Schreitwerk
US4252204A (en) * 1979-04-09 1981-02-24 Varian Associates Walking drag line
FR2507984A1 (en) * 1981-06-19 1982-12-24 Komatsu Mfg Co Ltd Laterally movable mobile crane - has double acting hydraulic cylinders to actuate outriggers to lift crane sideways
US4519468A (en) * 1983-03-24 1985-05-28 Fmc Corporation Steerable carrousel supported walking beam vehicle
US9988112B2 (en) 2011-12-16 2018-06-05 Entro Industries, Inc. Mounting structure with storable transport system
US10556631B2 (en) 2011-12-16 2020-02-11 Entro Industries, Inc. Low profile roller assembly
USRE46723E1 (en) 2011-12-16 2018-02-20 Entro Industries, Inc. Alignment restoration device for load transporting apparatus
US20170021880A1 (en) * 2011-12-16 2017-01-26 Entro Industries, Inc. Mounting structure with storable transport system
US9862437B2 (en) * 2011-12-16 2018-01-09 Entro Industries, Inc. Mounting structure with storable transport system
US10207756B2 (en) 2011-12-16 2019-02-19 Entro Industries, Inc. Mounting structure with storable transport system
US10202156B2 (en) 2014-08-20 2019-02-12 Hydraulic Systems, Inc. Stabilizer frame apparatuses and methods of using same
US10308299B2 (en) 2014-08-20 2019-06-04 Hydraulic Systems, Inc. Methods and systems for controlling movement of load transporting apparatuses
US10988191B2 (en) 2014-08-20 2021-04-27 Hydraulic Systems, Llc Load transporting apparatus and methods of using same
US10899401B2 (en) 2017-06-05 2021-01-26 Entro Industries, Inc. Yaw alignment system
US10793409B2 (en) 2017-07-12 2020-10-06 Entro Industries, Inc. Lifting loads with lifting devices
US10895882B2 (en) 2017-08-01 2021-01-19 Entro Industries, Inc. Controlling load transporting devices
US10889961B2 (en) 2017-08-08 2021-01-12 Entro Industries, Inc. Automatic walking for a load transporting apparatus
US11180319B2 (en) 2017-11-22 2021-11-23 Entro Industries, Inc. Skid system for load transport apparatus
US11407460B2 (en) 2018-05-31 2022-08-09 Entro Industries, Inc. Nonlinear walking apparatus
US20230213058A1 (en) * 2022-01-05 2023-07-06 Jeffery L. Johnson Joint for connecting an attachment to a hydraulic ram

Also Published As

Publication number Publication date
DE1634958B2 (de) 1976-07-01
DE1634958A1 (de) 1971-09-16
GB1154523A (en) 1969-06-11

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