US3896568A

US3896568A - Scaper blade having adjustable section

Info

Publication number: US3896568A
Application number: US440885A
Authority: US
Inventors: James E Hancock
Original assignee: Clark Equipment Co
Current assignee: Doosan Bobcat North America Inc
Priority date: 1974-02-08
Filing date: 1974-02-08
Publication date: 1975-07-29
Anticipated expiration: 1992-07-29
Also published as: ES434513A2

Abstract

A blade, especially for tractor scrapers, having a movable section which may be extended to increase the local penetration of the cutting edge. An adjustment mechanism is operable to extend or retract the section as required by ground conditions. In one embodiment this is a threaded actuator which is turned to manually adjust the section. In another, it is an hydraulic cylinder which may be operated from the cab of the machine to project or retract the section.

Description

United States Patent 1 1 Hancock [451 July 29,1975

1 1 ,SCAPER BLADE HAVING ADJUSTABLE SECTION [75] Inventor: James E. Hancock, Lubbock, Tex.

[73] Assignee: Clark Equipment Company,

Buchanan, Mich.

22 Filed: Feb. 8, 1974 21 Appl No.:440,885

[52} [1.8. CI. 37/141 R; 37/124; 37/141 T [51] Int. Cl E02f 9/28 [58] Field of Search 37/141 R, 141 T, 142 R, 37/142 A, 124, 126

[56] References Cited UNITED STATES PATENTS 1,885,326 11/1932 Brune 37/141 T 2,584,868 2/1952 Guess 37/142 R 2,828,558 4/1958 Reinhard.... 37/141 T 3,145,488 8/1964 French 37/141 R 3,272,559 9/1966 Haynes 37/141 R X 3,500,562 3/1970 Reinhard 37/141 R 3,645,021 2/1972 Sunerud 37/141 T 3,795,070 3/1974 Bronson 37/141 R X FOREIGN PATENTS OR APPLICATIONS 103,025 l/l917 United Kingdom 37/142 R Primary Examin'erE. H. Eickholt Attorney, Agent, or Firm.lack E. Toliver [57] ABSTRACT A blade, especially for tractor scrapers, having a movable section which may be extended to increase the local penetration of the cutting edge. An adjustment mechanism is operable to extend or retract the section as required by ground conditions. In one embodiment this is a threaded actuator which is turned to manually adjust the section. In another, it is an hydraulic cylinder which may be operated from the cab of the machine to project or retract the section.

4 Claims, 4 Drawing Figures SCAPER BLADE HAVING ADJUSTABLE SECTION BACKGROUND OF THE INVENTION 1. Field of the Invention The invention pertains to the art of mobile earth working machines and more particularly to selfpropelled, elevating tractor scrapers.

2. Description of the Prior Art It is not uncommon for tractor scrapers to work in hard clay or rocky soils which resist penetration of the blade. This considerably reduces the digging efficiency of the elevator. Blades with a solid, fixed portion protruding beyond the cutting edge increase the penetrating power in hard clay and assist in breaking up the soil beneath the elevator. Such blade protrusions or extensions will vary depending on the type of soil. A relatively sharp tooth-like projection may be used for ripping up roots and over-turning bolders, whereas a single wide-blade projection will be used in moist, heavy clay or compact soil.

No single blade is suitable in all types of soil, nor is it usually convenient to change blades in practice since each blade or blade section requires numerous bolts for securing it to the blade frame. As a result, it is normal practice to anticpate the type of ground conditions existing at the job site and install a blade at the garage having the desired configuration suited for the terrain. However, this often leads of inefficiency where some local soil conditions are unfavorable to the blade section installed. For example, if the blade has been outfitted with a narrow chisel for ripping, then patches of sandy soil would not be loaded with maximum efficiency.

A US. application Ser. No. 299,992 by J. E. Hancock filed Oct. 24, 1972 is assigned to the assignee of the present invention and describes a type of adjustable blade which can be changed in the field to suit actual ground conditions, but there is no actuator to make the adjustment mechanically.

SUMMARY OF THE INVENTION A blade has an adjustable section which is mounted on a shiftable plate or platform. In the rear most position, of the platform, the section is retracted with the edge being continuous with the cutting edge of the blade. An actuator is connected to the shiftable platform which may be operated by either manual or powered means to slide the platform out and thereby extend the portion of the edge on the adjustable section.

In the application of the invention on a tractor scraper, the blade platform is supported on a blade frame fixed between the walls of the scraper. A plurality of spaced, longitudinally extending runners underneath the platform slide on an upper, inclined suface of the blade frame. Guide ribs secured to the frame extend transversely between the runners. An actuator is connected to the platform and operates to extend or retract the blade platform.

In the preferred embodiment, screw and nut devices are turned to extend or retract the blade platform.

In another embodiment, the actuator is one or more hydraulic cylinders connected by hydraulic lines to a pump driven off of the tractor engine and controlled by a valve from the tractor cab.

Where the adjustable blade section is one or more narrow chisel teeth, a single actuator is associated with each chisel.

One of the main advantages of the invention is a blade having an adjustable section which can be quickly adjusted to accommodate varying ground conditions by using an actuator.

Another advantage is that blade adjustments can be made more frequently by hand or, if desired, without the operator leaving the cab using a powered actuator.

While these advantages are especially related to earth moving scrapers, other machines utilizing a blade, bucket or cutting edge for digging will be able to use the invention where otherwise frequent changes of blade shapes would be required.

These and other advantages will be more apparent by reference to the following detailed description of the invention which proceeds with a description of the drawings wherein:

DESCRIPTION OF THE DRAWINGS DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. I shows a two-wheeled, over-hung tractor l0 towing a two-wheeled scraper 12. The scraper 12 has a pair of arms 13 connected at the forward ends of the scraper side walls 14. The arms 13 are joined by a cross beam 15 at the front. A yoke 16 is attached to the cross beam and extends forwardly for mounting on a kingpin coupling 18. A pair of steering jacks 20, one on each side of the yoke, is controlled by a steering valve (not shown) operated by the steering wheel 22 of the tractor for producing the turning movements of the tractor relative to the scraper about the vertical steering axis of I the kingpin coupling 18. The tractor l0 steers by turn ing relative to the scraper on the steering axis as the jacks 20 are extended on one side and retracted on the other. The tractor is supported on wheels 25 and the scraper on wheels 26. The scraper side walls 14 define an open bowl having an ejection mechanism (not shown). An end gate, the upper portion of which is shown, is pushed by the ejection mechanism to expel] dirt through the bottom of the bowl. A rolling door 38 closes an opening in the bottom of the bowl through which the dirt is dumped. In front of the rolling door 38, fixed to the scraper side walls, is a scraper blade 30 mounted between moldboards 31. An elevator 32 inclines downwardly at the front of the bowl. The elevator is comprised of a plurality of chain driven drags or flights 33 which strike the ground when the blade 30 is lowered for digging and assists in loading dirt into the bowl as each flight passes around the foot shaft of the elevator counterclockwise as view in FIG. 1. A pair of lift cylinders 35, one on each side of the yoke 16, is attached at the lower end of the cylinders to the mold boards 31 and at the upper end to the cross beam 15. The cylinders 35 are controlled from the cab of the tractor and may be extended to lower or retracted to raise the bowl.

Referring now to FIG. 2, the blade includes an adjustable section 40. In the present embodiment, it comprises a relatively wide center section of the blade, flanked on either side by stationery blade sections (not shown), but forming with the adjustable section 40, a continuous cutting edge 42 extending substantially across the front of the scraper. A blade frame 43 is secured between the mold boards 31, usually by welding around the periphery at each end, such that it provides a solid, upper inclined surface 45 for supporting the blade 30. The adjustable section 40, is considered to include a slidable platform 44 on which is bolted replaceable blade elements 46. As seen in FIG. 3 the blade platform 44 includes an upper plate or deck 48 supported from underneath by a plurality of spaced runners 49, each of which has a web 50 joined at its upper and lower ends by flanges 51. The upper flanges 51 are secured to the underside of the plate 48 while the lower flanges 51 are free to slide on the upper surface 45 of the blade frame 43. Guide ribs 55 spaced longitudinally of the support beams 49 are secured to the upper surface 45 of the blade frame. The opposite ends of each guide ribs 55 are tapered (FIG. 3) to provide parallel guide paths for the support beams 49. As can be seen in FIG. 3, the tapered ends of the ribs overlie the lower flanges 51 of the support runners preventing the blade platform structure from being lifted off of the blade frame 43. Thus a sliding motion is permitted relative to the blade frame. The guide ribs are located at intervals along the sliding path of the runners so as to guide the blade platform as it is being extended or retracted.

According to the preferred embodiment of the invention an adjustment mechanism is provided for extending and retracting the adjustable section 40 which includes a plurality of nut and screw actuators 62 mounted on the upper surface of the blade frame behind the blade platform 44. Each nut and screw actuator 62 includes a relatively long, threaded screw 63 which is threaded in a nut 64 secured to the blade frame. A cylindrical collar 65 of the screw 63 below the nut 64 has a number of drilled holes 66 for accommodating a spanner wrench to be used in turning the screw. A swivel bearing 68 is mounted at the lower end of the screw to permit turning and is secured in a cup 67 attached to the upper end of the runner 49. A jamb nut 70 is loosened to permit the screw 63 to be advanced or retracted through the nut 62 after which the jamb nut is retightened.

It will be appreciated that the adjustment mechanism 60 provides an effective and efficient means for adjusting the whole digging section. In the preferred embodiment, the adjustable section comprises a relatively wide portion of the blade and therefore a plurality of screw and nut actuators 62 are emloyed. The operator need only insert the spanner wrench in the holes 66, loosen the jarnb nut 70, and turn the screw 63 of each actuator 62, adjusting each to the same length, to obtain the desired penetration of the blade. Where the adjustable section isa narrow chisel, it will be satisfactory to have only one screw and nut actuator for each chisel.

ANOTHER EMBODIMENT OF THE INVENTION Referring now to FIG. 4, wherein parts similar to those shown in FIGS. 2 and 3 are identified using the same numerals with a letter suffix, the blade 30a has an adjustable section 400. A replaceable blade element 46a defines a cutting edge 42a. In this embodiment, the blade frame is omitted. While it would be utilized on a scraper, other structures may not employ such a frame, e.g., a digging bucket for an end loader, thus the embodiment in FIG. 4 is intended for more general application. Specifically, the embodiment in FIG. 4 is intended for application where more frequent blade adjustment is required and, in that case, remote operation of the blade section is desirable by means of a powered actuator.

In FIG. 4, one or more hydraulic cylinders is protected by a stationary plate 76. The rod end of the cylinder 75 is connected to the rear end of the blade platform 44a and, with the blade in the extended positions as shown in FIG. 4, the cylinder rod is protected by a dirt shield 78 which slides out from beneath the stationary plate 76 and is retracted beneath it when the blade section is retracted. The cylinder 75 is connected by a valve 78 to a pump 79. Hydraulic fluid is supplied to the pump from a reservoir 80. By actuating the valve 78, the operator may extend or retract the cylinder by any amount desired, thus changing the configuration of the cutting edge 42a without having to leave the cab of the machine.

While alternate embodiments of my invention have been disclosed, it will be understood that these descriptions are for purposes of illustration only and that various' modifications and changes can be made to my invention without departing from the spirit and scope of it. Therefore, the limits of my invention should be determined from the following appended claims.

I claim:

1. ln mobile earth moving equipment including apparat'us for raising and lowering a blade device having a cutting edge adapted to be lowered to the ground for digging, the improvement comprising an adjustable section forming a portion of the cutting edge and defining a substantially continuous edge in one position and a projected edge for increasing local penetration in another position, said adjustable section comprising a shiftable element mounting said cutting edge portion, an actuator attached to the shiftable element operable for moving it between said positions and means for guiding the shiftable element including a blade frame fixed on the equipment, said blade frame having an upper, downwardly inclined surface, spaced runners supporting said shiftable element on the upper surface of the blade frame and transversely extending guide ribs between said runners for guiding said shiftable element in a path parallel to the inclined surface of the blade frame.

2. In a mobile scraper having a dirt collecting bowl defined by side walls, a floor and end wall, being open at' the front, a scraper blade fixed between the side walls at the lower front portion thereof and inclining forwardly to a cutting edge adapted to be lowered to the ground for digging, said scraper blade comprising a blade frame secured between the side walls having a forwardly inclined upper surface, a plurality of blade sections mounted on the upper surface of the blade frame in side-by-side relationship defining a substantially continuous upper surface with the forward ends thereof defining a substantially continuous cutting edge, one of said blade sections being movable between a retracted position and an extended position for inthe actuator includes a threaded element connected to the movable blade section, a nut mounted on the blade frame through which the threaded element extends and means for manually turning the threaded element for extending or retracting in the movable blade section.

4. The improvement according to claim 2 wherein the actuator includes a double-acting hydraulic cylinder connected between the movable blade section and blade frame which may be operated for extending or retracting the blade section.

Claims

1. In mobile earth moving equipment including apparatus for raising and lowering a blade device having a cutting edge adapted to be lowered to the ground for digging, the improvement comprising an adjustable section forming a portion of the cutting edge and defining a substantially continuous edge in one position and a projected edge for increasing local penetration in another position, said adjustable section comprising a shiftable element mounting said cutting edge portion, an actuator attached to the shiftable element operable for moving it between said positions and means for guiding the shiftable element including a blade frame fixed on the equipment, said blade frame having an upper, downwardly inclined surface, spaced runners supporting said shiftable element on the upper surface of the blade frame and transversely extending guide ribs between said runners for guiding said shiftable element in a path parallel to the inclined surface of the blade frame.

2. In a mobile scraper having a dirt collecting bowl defined by side walls, a floor and end wall, being open at the front, a scraper blade fixed between the side walls at the lower front portion thereof and inclining forwardly to a cutting edge adapted to be lowered to the ground for digging, said scraper blade comprising a blade frame secured between the side walls having a forwardly inclined upper surface, a plurality of blade sections mounted on the upper surface of the blade frame in side-by-side relationship defining a substantially continuous upper surface with the forward ends thereof defining a substantially continuous cutting edge, one of said blade sections being movable between a retracted position and an extended position for increasing the local penetrating power of the cutting edge, the improvement comprising a shiftable blade platform supporting said movable blade section on the blade frame including, spaced, longitudinally extending runners slidable on the upper surface of the blade frame, transversely extending guide ribs attached to the blade frame and extending laterally between the runners defining parallel guide paths, and an actuator attached to the blade frame operable for extending or retracting said blade section.

3. The improvement according to claim 2 wherein the actuator includes a threaded element connected to the movable blade section, a nut mounted on the blade frame through which the threaded element extends and means for manually turning the threaded element for extending or retracting in the movable blade section.