US2482910A

US2482910A - Mounting for soil treating units

Info

Publication number: US2482910A
Application number: US567228A
Authority: US
Inventors: Henry C Hettelsater
Original assignee: Harnischfeger Corp
Current assignee: Harnischfeger Corp
Priority date: 1943-12-13
Filing date: 1944-12-08
Publication date: 1949-09-27
Anticipated expiration: 1966-09-27
Also published as: US2424460A; US2529656A; US2424459A; GB602061A; FR948968A; DE841762C

Description

Segt H. c. HETTELSATER 2,482,910

MOUNTING FOR SOIL TREATING UNITS Original Filed Dec. 13, 1943 4 Shee'ts-Sheet 1 IN V EN TOR. 19 4 4447 0 Mali, Y

[ a da-5 ATTOAA/EK S p 1949- H. c HETTELSATER MOUNTING FOR SOIL TREATING UNITS i 4 Sheets-Sheet 2 Original Filed Dec.

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ATTOP/VL'K P 1949- H. c. HETTELSATER MOUNTING FOR SOIL TREATING UNITS 4 Sheets-Sheet 3 Original Filed Dec. 13; 1943 INVENTOR. M7 6 Mad-m BY P 1949- H. c. HETTELSATER I MOUNTING FOR SOIL TREATING UNITS 4' Sheets-Sheet 4 Original Filed Dec.

INVENTOR. I W C flown/2, Y

Patented Sept. 27, 1949 Henry 0. Hettelsater, Whitefish Bay, Wis., as-

signor to Harnischifeger Corporation, Milwaution of Wisconsin kee, W1s., a corpora Original application December 13, 1943, Serial Divided and this application December 8, 1944, Serial No. 567,228

6 Claims. (01. 94-40) sisting weathering action and sustaining traffic,

and it resides in an improved form of such apparatus wherein the instrumentalities by which the native soil is removed are subject to precise control, thus "permitting a substantially uniform layer of soil to be removed while the apparatus is passing over changes of contour of the earth and in which such removal is carried forward continuously by progressive removal of small increments so as to deliver the removed material in substantially pulverized condition accessible to a bonding agent to be introduced and in which the removed and rare-pulverized material is additionally pulverized by an impact action against a moving target capable of returning insufiiciently pulverized material for successive impacts, and in which pulverized material is impelled in a regulated and positive manner into milling apparatus in which added bonding agent may be thoroughly intermixed with the soil undergoin treatment prior to its return to its intended position on the surface of the earth.

Substantial advantages may be obtained in the construction of low cost pavements under many conditions by employing the native .soil already in place over the course which the pavement is intended to follow and by mixing such soil thoroughly with a bonding agent such as Portland cement or bituminous material. In order to accomplish this, the soil material must be re" moved, pulverized thoroughly, mixed with the bonding material, returned to the position on the roadway desired and then rolled to compact i-t.

Numerous appliances or series of appliances for accomplishing these operations have been proposed from time to time and many have been constructed and used. Such apparatus, how ever, has been subject to serious drawbacks,

either because of its complexity and cost or be- "1:

cause of its inability to follow the varying con tour of the grade .b'eing worked upon without difficult and expensive improvisations or because of inadequate pulveriza'tion of the excavated material, or because of defective mixing of the bonding agent with the material before returning the same to the roadway, or for other reasons. It is one object ofth'is invention to obviate the difficulties heretofore experienced and to provide an apparatus capable iof being so controlled as tooP- erate success-fully' and easily where changes in grade are involved and which will produce a degree of .pulverization and uniformity of admixture of bonding agent which will result in a pavement of superior strength and endurance.

This invention is herein described by reference to the accompanying drawings forming a part hereof in which there is set forth by way of illustration and not :of limitation one specific form in which the apparatus of this invention may be embodied.

This application is a division of my copending application Serial No. 514,177, filed December 13, 1943, which has matured as Patent No. 2,424,459, and relates more particularly to the supporting and drive of the soil treating unit.

In the drawings:

Fig. 1 is aside elevation view the apparatus of this invention;

Fig. 2 is a sectional view in elevation for the of one form of purpose of showing certain details of the adjusting apparatus viewed through the plane 2 -2, indicated in Fig. 1;

Fig. 3 is atop plan view of the apparatus shown in Fig. 1; .Fig. 4 is .a diagrammatic showing of the .drive system employed in the apparatus shown in Fig. 1; r

Fig. 5 is an enlarged detailed top plan view with parts broken away and in section of the treating part of the apparatus of this invention;

Fig. 6 is a diagrammatic showing of the piping connections employed in the control system of the apparatus.

The form of the apparatus of this invention shown in the drawings, particular reference being made to Figs. 1 and 3, comprises as principal elements a transporting unit land a soil treating unit '2.

Transporting unit Chassis-The chassis .of the transporting unit I is made up of a pair of endless track type treads 3 mounted oneon each side of the machine to form a tractor base, the same being of conventional construction and therefore generally depicted in outline only. The tractor base is secured to and supports a main frame made up of two transversely joined longitudinally extending box girders sand 5 which serve additionally as fluid supply tanks in a manner and for purposes described more in detail hereinafter. A transverse member ii at the rear of themachine joins the tanks 4 and 5 whilea transverse member I joins the tanks 4 and 5 at the forward end of the machine to complete the main frame. Between the tanks 4 and 5 and carried upon the cross members 6 and l are a pair of longitudinal subframe members 8 and 9.

Propelling drive sysfem.Mounted on the forward end of the sub-frame members 8 and 8 is an engine I having an automotive type engine clutch facing rearwardly in the housing II from which emerges a stub shaft I2 operatively connected to the driven part of the clutch. The shaft I2 carries a sprocket wheel I3 contained within a guard I 4 and engaged by a chain I5 to be described in greater detail hereinafter. The rear end of shaft I2 terminates at and is drivingly connected to the driving part of a torque limiting friction clutch I6. The clutch I8 serves a protective function made advisably by the fact that the capacity of engine It is such as to be substantially in excess of that required for simple propulsion of the apparatus and accidental stalling of the propelling mechanism might otherwise result in damage to parts properly proportioned for the duty expected of them but not proportioned for the excessive capacity of the engine II). The clutch I 5 is therefore arranged to slip whenever a condition arises which would tend to apply there to a torque in excess of that entailed under the most severe propelling conditions to be expected.

The clutch I6 is drivingly joined by a. connecting shaft II with a change speed gear transmission I8 of conventional automotive type having four selective forward speeds and one reverse speed. A shifting lever I9 extends upwardly from the transmission I8 within reach of a person operating the apparatus, standing on a platform 2t? or seated on a seat 2|. Directly coupled to the output end of the transmission I8 is a selective reverse and reduction gear transmission 22 having one selective forward speed and one selective reverse speed. The output of reverse and reduction gear transmission 22 is in turn coupled directly with a worm driven differential gear 23, having two laterally extending propelling shafts, one on each side, carrying steering brakes 24 and 25 and propelling sprockets 26 and 21 contained respectively within the guards 28 and 29.

Referring now particularly to Fig. 1, the sprocket 2! is shown in meshing engagement with an endless chain 38 which passes over an idler take-up sprocket 3! and around and in meshing engagement with a tractor drive sprocket 32 all shown in dotted lines, the latter being in driving engagement with the tread 3 appearing. In like manner, but not shown, the sprocket 28 is joined in driving engagement with the tread 3 on the opposite side of the machine.

Propellz'ng control system.-Actuator linkages for the steering brakes 24 and 25, of conventional type and therefore not shown to avoid confusion in the drawings, are joined to a steering lever 32 (see Fig. 3) in such manner that when the lever 32 is thrust forwardly brake 24 is applied and when pulled rearwardly brake 25 is applied. In mid position of the lever 32, neither brake is applied and the lever 32 is advantageously arranged to be self returning to said mid position. In this way When the apparatus is being propelled, steering may be accomplished through the cooperative action between the brakes 24 or 25 on the one hand and the differential gear 23 on the other hand. For example if brake 24 be applied the rate of driving of the tread on the left side of the machine is retarded and that on the right side of the machine accelerated an equivalent amount and the apparatus turns toward the left.

If brake 25 is applied, the opposite result is obtained, and if neither brake is applied, the apparatus travels in a straight line unless and until some external agency interferes.

The rate at which the apparatus is moved, its direction, and the amount of tractive effort which it is capable of exerting is regulated by means of the selective transmissions I8 and 22. To control these instrumentalities the shifter member I9 previously referred to is employed to control transmission I8, and the shifter member of transmission 22 is extended by conventional means not shown and omitted to avoid confusion in the drawings, to a shifting lever 33 mounted within reach of the operator. To permit shifting of the transmissions l8 and 22, the clutch previously referred to and contained Within the housing I I, is connected by conventional means not shown, and omitted from the drawing to avoid confusion, to a clutch shifting lever 34 mounted within reach of the operator.

By means of the selective change speed gearing arrangement shown and described, the operator has at his disposal, with the transmission 22 in forward driving position, four forward driving speeds and one reverse speed depending upon the position of transmission I8 which is selected. With the transmission 22 in reverse position the operator has at his disposal an additional forward driving speed and four reverse speeds. I prefer to employ in the case of the transmission 22 a very substantial reduction, say about four and one-half to one, in the driving ratio of the forward speed and a driving ratio near to unity for the reverse driving speed.

In the case of transmission I8, prefer that the driving ratios of the various speeds be approximately one to one for the highest forward speed, about two to one for the higher intermediate forward speed, and about three to one for the lower intermediate forward speed, about six and onehalf to one for the lowest forward speed and about eight to one for the reverse speed. Compounding the ratios of the two transmissions, the

' over-all reduction for the several selective combinations result in the following:

Forward Speeds Ratio Transmission 18 Transmission 22 Low .4 Forward About 99 to 1 Lower intermediatcdo About 13 to 1 Higher intermediate do About 9 to 1 H h d0 i. Abou 4%to1 Reverse About 8 to 1 Reverse Speeds Ratio Transmission 18 Transmission 22 Reverse Forward About 36 to 1 Low Reverse. About 6% to 1 Lower intermediate do About 3 to 1 Higher intermediate ..do About 2 to 1. High do About 1 to 1 From this it will be observed that very low forward working speeds are provided but in reverse a much greater rate of travel is available. Taking advantage of this relationship I prefer to employ such a reduction in the driving ratio of the worm in differential 23 and in the propelling sprockets that forward working speeds as low as about 5 feet per minute are available in which event speeds as high as about 2 miles per hour maybe attained in reverse, so that the machine may transport itself for short. distances to. and from, or between jobs or for return travel to take up an adjacent parallel pass. without an undue expenditure of time.

The engine Hi may be regulated as to speed by means of a throttle with or without. a. governor as desired and these parts being of conventional form are not. shown.

Soil treating unit M confine-The soil treating unit 2 as appears in Fig. 1 is mounted upon the downwardly and rearwardly extending arms and 36 which are parts of a fulcrumedelevating frame, made up of said arms 35 and 35-, a tubular cross member- 31 welded thereto, a pair of bell crank

arms

38 and 39, a tubular cross member 40 welded thereto and. diagonal braces M and 42.. The en tire elevating frame is fulcrumed upon pivots 4:3.

and 44, so that the lower end of the

arms

35 and 36 which engage the treating unit 2 are capable of a swinging movement, a large component of which. is vertical. To produce this movement a. pair of hydraulic cylinders and 46 are interposed respectively between rearward extensions 4&1 and 48 secured to-the rear of the transporting unit and the cross member All. When fluid is fed to the cylinders 45 and 46, the elevating frame. is raised, and when fluid is exhausted, it is lowered.

A supply of fluid for cylinders 45 and 46 is provided by continuously running pump 49 mounted on engine 1.0 to be driven thereby. Connections between the pump 49 and the cylinders 45 and 45 are of conventional form and therefore not shown except diagrammatically in Fig. 6. In Fig. 6, pump 49 is shown. arranged to discharge fluid into pipe 50 which joins with. volume limiting valve 5| through which fluid has free passage into pipe 52. Valve 5| is so arranged that a branching stream of fluid of limited volume may escape therefrom into pipe. 53 for purposes to be later described. Fluid passing through pipe 52 is free when called for through pipe 54 and thence by passing through pipe 55 to reach piston type reversing valve 55 having operating handle 51. The valve 55 is provided with three ports all of which are closed with the operating handle 5'! in off position. With the handle 51. in lifting position the pipe 55 is brought into communication with the pipe 58 and. the other port is closed and fluid is thus supplied through

branch pipes

59 and 60 to the cylinders 45 and 46. With the handle 51 in lowering position, the port connecting with pipe 55 is closed and pipe 58 is brought into communication with discharge pipe 6| and thence through return pipe 62 with a sump G3 to which fluid may freely drain.

Pipe 52 from which pipe 54 branches joins with a second volume limiting valve 84 similar in all respects to the valve 5| through which fluid may freely pass to pipe 65 while a limited side stream may escape into pipe 56 for a purpose to be more fully described. Pipe 65 in turn joins with a fixed amrture back pressure orifice (51 so constructed as to permit fluid to pass therethrongh but to maintain ahead of it a pressure equal to the intended operating pressure of the system. The capacity of pump 49, at the pressure maintained by orifice 61 is such that it exceeds the volumetric requirement of the cylinders t5 and 45 when lifting at the maximum rate desired, by an amount in excess of the maximum rate of esto branch therefrom cape of fluid through pipes 55 and 66*, previously referred to, and pipe 68 not yet described. All excess fluid passes through Orifice a1, pipe 69', and pipe 6-2: to sump 63. Operating: handle 51 is located as shown in Fig. 3 within easy reach of the operator.

For additionally adjusting the position of the treating unit 2' with. respect. to the transporting: unit I and the. soil to be worked: upon, a pair of turnbuckle rods 10 and TI: which support the overhanging rear portion of the. treating, unit. 2 are joined at their upper ends respectively with bell cranks l2 and 13' pivotally mounted respec-: tively upon the

arms

38 and 39. The cranks 12 and 1-3 are subject to positional adjustment by and are inengagement respectively with the plungers of a pair of hydraulic cylinders 14 and 15' supported at their lower ends respectively upon arms 35 and 3.6. In this way there is pro.- videda limited amount of tilting movement of the unit 2 with respect to the

arms

35 and 36 to which it is pivotally connected by the pins I5 and 11.

Supply of fluid and control of the same for actuating cylinders M and 15 is similar to that described in connection with cylinders. 45 and 45. Fluid is supplied through pipe 68 and reversing. valve it which connects through pipe 19 with pipes 88 and El!v as shown in Fig. 6 only. Exhausted fluid from the cylinders I4 and i5 and the valve 18 passes through pipe 82 into pipe 62 and thence into sump 63. For controlling valve l8 an operating handle 83 located as shown in Fig. 3 is provided.

By means of the mounting arrangement shown and described, the treating unit 2 may be brought to and held at any working level desired by manipulation of the cylinders 45, 45, M, and H5, or may be lifted clear of the surface upon which the apparatus is traveling, so that the apparatus may travel to and from the place where work is to be carried on. In the holding position the valves 56 and F8 are in their lapped positions. Furthermore, by manipulation of cylinders 'M and E5, the angular relationship of the treating unit 2 with respect to the base of treads 3 may be'readily adjusted. For example, if the work being performed passes over the crest of a the operator can permit suflicient fluid to escape from cylinders 14 and 15 so that the rear of the treating unit 2 drops just the right amount to conform to the change in configuration of the grade. If the grade is changing in the opposite way, the rear of treating unit 2 can be raised accordingly. Thus the operator can, without interruption of the work, continuously treat a substantially uniform layer of the material being worked upon regardless of alteration in the grade.

The overhanging treating unit 2 is without any trailing support in the form of wheels or skids which would bear upon the completed treated layer. 7 This is of importance because the treated layer after formation must be compacted by rolling and any area precompacted prior to rolling, persists as a non-uniform area in the finished pavement after rolling. The avoidance of trailing support for the overhanging treating unit 2 is accomplished according to this invention by placing the heavy prime mover Ill far forward on the transporting unit I, thus bringing the combined center of gravity of the entire assembly well within the ends of the treads'3. It is preferred that the disposition of loading be such.

that this combined center of gravity under static hill, 7

conditions is located somewhat to the rear of center of treads 3 so that the effect of the engagement of unit 2 with the soil being worked upon will bring the resultant loading of the treads 3 close to the center thereof under dynamic or working conditions.

Housing.The treating unit 2 is mounted within a housing serving as a frame made up of double walled side plates 04 and 85 joined at the front by curved end plate 86 and at the rear by curved end plate 81. The open top of the rectangular frame thus provided is covered by four similar removable hatch covers each designated by the numeral 88. To ensure rigidity, a tubular cross brace 89 is secured to and extends between the side plates 8-; and 85 directly beneath the points of attachment of the rods I and H This frame is pivotally secured to the

arms

35 and 36 as previously described by means of the pins 16 and I! which are held respectively between the double walls of

side plates

84 and 85.

Cutting mien-Mounted to turn in bearings provided therefor in the

side plates

85 and 84 near the front thereof is a cutting rotor I0! carried on a shaft 90 having a tubular center portion with reduced extensions at the ends. One of these extensions is designated 8! and appears in Fig. where it may be seen as extending through a bearing 92 and outwardly beyond the side plate 84.

Secured by welding to the tubular portion of shaft 90 in axially and angularly spaced arrangement as shown, are a plurality of cutting tine sprockets 93. The inner end of a flat springsteel tine 96 is removably clamped in each of the sockets 93. The cutting ends of the tines 96 are enlarged, and if desired, armed with material of exceptional abrasion resistance. The angular spacing of the sockets 93 and the tines held therein is so distributed that successive tines engage the material being excavated in rapid succession, so that there is an avoidance of the shock which could otherwise be occasioned by a large number of tines all initiating their cutting action at the same moment. The cutting rotor is operated in a clockwise direction as viewed in Fig. 1 and preferably at such a rate With relation to the forward speed of the apparatus that material excavated is out or shaved away in small increments akin to the action of a milling cutter. The rate of rotation of the cutting rotor furthermore is preferably such that material is projected against the target rotor with considerable force to cause a disintegrating and pulverizing action.

Target 'roto'r.Spaced from and parallelly disposed to the rear of cutting rotor MI is a target or material intercepting rotor I02 mounted on a shaft I03 having a tubular center portion with reduced end extensions carried in bearings held in the side plates 04 and 85. One of the extensions of shaft I03 is designated I05 and appears in Fig. 5 Where it may be seen passing through a bearing I04 held in the side plate 84. The tubular portion of shaft I03 is provided throughout its length with four equally spaced radially extending longitudinal fins I05 welded in place.

Attached to the fins I06 by bolting are a plurality of closely spaced resilient steel tongues I0! of uniform length, the tips of which are bent slightly as shown and cut at a slight angle so as to sweep a substantiall cylindrical surface in spite of the bend of the tip. The tips of the tongues I01 are bent so as to cause material engaged by the same to move laterally to some extent. As appears more clearly in Fig. 5, some of the tongues I0! are bent to cause lateral movement of material in one direction and some in the other direction. The arrangement is such that one pair of diametrically opposed sets of tongues tends to divide material at the center of rotor H12 and move it toward the ends thereof; whil the intervening pair of diametrically disposed sets of tongues tends to gather material from the ends of rotor Hi2 and move it toward the center. This general arrangement is subject to the exception that in the case of the sets of tongues bent to cause outward movement of material, the outer tongues designated IG'IA are oppositely bent to minimize loss of material beyond the ends of the rotor E52. Since the object sought is an alternate transverse mingling action of the material, other arrangements of the bent tongues It? may be resorted to with equal effectiveness, and some modification in this regard may be found advantageous in handling difierent types of material.

The rotor m2 is arranged to be turned in a counterclockwise direction by driving means to be described more fully hereinafter. The rate of rotation of target rotor I02 is preferably such that material deposited before it and impinging upon it by reason of the action of cutting rotor ml, is moderately tossed back into the more rapidly turning cutting rotor I0! from which it is again returned forcibly into the target rotor I02. In the course of the back and forth movement of the material thus created, it is raised to successively higher levels in the target rotor I 02 until it is finally caught by the target rotor I02 and tossed rearwardly. In this way the material is subjected to repeated impact and thus pulverized to a very substantial degree. Furthermore, in cases where dry material, such as sand or Portland cement, is spread upon the surface being worked upon in advance of the apparatus while working, a very thorough mixing and intermingling of the added dry particles with the pulverized soil is accomplished. intermingling and mixing action, the slight lateral movement caused by the bent tips of the tongues l0! brings about a lateral blending also, which tends to obliterate any lack of uniformity transversely of the work strip caused by streaked spreading of the dry material.

While the target rotor M2 is in effect a complete paddle wheel because of the close spacing of the tongues I07, each tongue is independent and resilient so that it may yield if an obstruction such as a deeply buried boulder not cut away by the resilient cutting tines of the cutting rotor I 0! is encountered. Because the tongues I01 are spaced from one another slightly, and are bent at their tips and may yield and thus incompletely sweep the excavated subgrade, successive sets of tongues making up the rotor 52 are staggered slightly as may be observed in Fig. 5 to ensure engagement of all material excavated by the target rotor I02.

Bidding miZZ.-Behind the target rotor I02 within the frame of the treating unit 2, and mounted upon tubular shafts I03 and H39, extending between bearings secured in

side plates

84 and 85, are a pair of blading mill rotors H0. The rotors of mili H0 are furnished with a plurality of welded in place blade sockets i Ii spaced from one another as shown. Carried in the blade sockets IiI are the shank portions of replaceable blades I I2.

The shaft spacing of the blading mill rotors In aid of this operated by a hydraulic cylinder, which is designated I84, similar to that for the valve I62, and connects the pipe Zill with the pipe I 99, which as previously noted connects with a pressure pipe 66 and a release pipe I98. The action of this hydraulic cylinder through the opening of the valve I9! is similar to that just described in connection with the valve I62, and since this hydraulic mechanism for shutting off and controlling the amount of binder fluid does not form a part of the present invention, further description thereof is deemed unnecessary.

From the above description it will be noted that while the machine is operating, power is transmitted to the cutting rotor lfli, the intercepting rotor H12, and the blading mill rotors H0. The action of these rotors on the material is more particularly described in the previously referred to application, but in general the action is to blend and pulverize the material being treated, mix this blended and pulverized material with a binder ingredient introduced through the pipe I69, and then mix the binder ingredient with the material in the blading mill before depositing the same on the subgrade.

In starting a typical treating operation, the treating unit 2 is raised by the action of both sets of lifting cylinders, and then cylinders 45 and 46 are gradually relieved of their fluid while the rotors of the treating unit are turning. As soon as established grade is reached, fluid is allowed to escape gradually from cylinders 14 and 75 while the transporting unit i is placed in forward movement. Escape of all fluid from cylinders '75 and I4, however, is delayed until the amount of forward movement of transporting unit i is substantially equal to the effective length of the treating unit 2 at which time all rotors may be brought to the operating grade. In this way the apparatus of this invention may be conveniently operated by a single operator so as to dig itself in after which the routine treatment of the strip to be worked upon likewise progresses under the complete control of a single operator as long as supplies equal to the requirements of the machine are furnished.

While this invention has herein been described by reference to one specific instance of its embodiment and use, it is intended that the protection to be alforded hereby be not unnecessarily limited thereby, the intent being that such protection shall extend to the full limit of the inventive advance herein disclosed as defined by the claims to be hereto appended.

What I claim as my invention is:

1. In a soil treating apparatus, the combination comprising a transporting unit movable over a surface to be treated and including a frame, an overhanging soil treating unit disposed to the rear of said transporting unit, an elevating member having a pair of arms pivoted at the rear of said frame on a single horizontal axis for vertical swinging movement and pivotally connected at their ends to the front of said soil treating unit, power operated means connected to said arms to SWing said elevating member and to hold the same in adjusted positions to which it is swung whereby the front end of said treating unit may be raised and lowered, and a supplementary power operated lifting means mounted on and carried by said elevating member to move therewith cooperatively engaging said treating unit at a point spaced from the pivotal attachment of said elevating member the same being adapted to support the rearward end of said treating unit and to adjustably lift and lower the same independently of the movement of said elevating member whereby said treating unit may be leveled and inclined thereby in each adjusted position of said elevating member, and means on said transporting unit for controlling said power operated means and said supplementary power operated lifting means.

2. In a soil treating apparatus, the combination comprising a transporting unit movable over a surface to be treated and including a frame, an overhanging soil treating unit disposed to the rear of said transporting unit, an elevating member having a pair of arms pivoted at the rear of said frame on a single horizontal axis for vertical swinging movement and pivotally connected at their ends with the front of said soil treating unit, hydraulic means connected to said arms to swin said elevating member and to hold the same in adjusted positions to which it is swung whereby the front end of said treating unit may be raised and lowered, and a supplementary hydraulic lifting means mounted on and carried by said elevating member to move therewith cooperatively engaging said treating unit at a point spaced from the pivotal attachment of said elevating member the same being adapted to support the rearward end of said treating unit and to adjustably lift and lower the same independently of the movement of said elevating member whereby said treating unit may be leveled and inclined thereby in each adjusted position of said elevating member, and control means for said first named hydraulic means and said supplementary lifting means mounted on said transporting unit in a position accessible to the operator thereof.

3. In a soil treating apparatus, the combination comprising a transporting unit movable over a surface to be treated, an overhanging soil treating unit disposed to the rear of said transporting unit, a pair of elevating arms mounted for vertical swinging movement on the rear of said transporting unit on a single horizontally disposed pivotal mounting and pivotally attached at their swingable ends to the front of said soil treating unit, means for swinging said elevating arms and for holding the same in adjusted positions to which they are swung whereby the front end of said treating unit may be raised and lowered, and a supplementary lifting means mounted on and carried by said elevating arms to move therewith and cooperatively engaging said treating unit at a point spaced from the pivotal attachment of said elevating arms the same being adapted to support the rearward end of said treating unit and to adjustably lift and lower the same independently of the movement of said elevating member whereby said treating unit may be leveled and inclined thereby in each adjusted position of said elevating arms and control means on said supporting unit for said supplementary lifting means.

4. In a soil treating apparatus, the combination comprising a transporting unit movable over a surface to be treated, an overhanging soil treating unit disposed to the rear of said transporting unit, a pair of elevating arms mounted for vertical swinging movement on the rear of said transporting unit on a single horizontally disposed pivotal mounting and pivotally attached at their swingable ends to the front of said soil treating unit, a pair of hydraulic cylinders interposed between said transporting unit and said arms for swinging said arms and for holding the same in adjusted positions to which they are swung whereby the front end of said treating unit may be raised and lowered, a second pair of hydraulic cylinders mounted on and carried by said elevating arms to move therewith and cooperatively engaging means joined to said arms and to said treating unit at points spaced from the pivotal attachment of said elevating arms and controlled by said second pair of cylinders the same being adapted to support the rearward end of said treating unit and to adjustably lift and lower the same independently of the movement of said elevating arms whereby said treating unit may be leveled and inclined thereby in each adjusted position of said arms, and control means on said transporting unit for said hydraulic cylinders. 5. In a soil treating apparatus, the combination comprising a transporting unit movable over a surface to be treated including a frame, an overhanging soil treating unit disposed to the rear of said transporting unit, a pair of rigidly interconnected elevating arms mounted on said frame for'vertical swinging movement about a single point of pivotal oscillation on the rear of said transporting unit and pivotally connected at their ends to the front of said soil treating unit, a pair of hydraulic cylinders interposed between said arms and said transporting unit for swinging said arms and for holding the same in adjusted positions to which they are swung whereby the front end of said treating unit may be raised and lowered, a bell crank lever mounted on each of said arms, and a supplementary hydraulic cylinder mounted on and carried by each of said arms to move therewith interposed between the same and said bell crank levers, and supportin rods operatively connecting said bell crank levers to said treating unit at points spaced from the pivotal attachment of said arms the same being adapted to support the rearward end of said treating unit and under the action of said supplementary hydraulic cylinders to adjustably lift and lower said rearward end independently of the movement of said arms whereby said treating 14 unit may be leveled and inclined thereby in each adjusted position of said arms, and control means on said transporting unit for all of said hydraulic cylinders.

6. The combination with a transporting unit, of an overhanging soil treating unit disposed to the rear of said transporting unit, a pair of rigidly interconnected bell cranks having a horizontally disposed pivotal mounting on said transporting unit and having arms pivotally connected by a horizontally disposed pivotal mounting to the forward end of said treating unit, means for swinging said bell cranks to raise and lower the forward end of said treating unit, a pair of bell crank levers carried by the other arms of said bell cranks operating connections between said second named bell cranks and the rearward portion of said treating unit, and means for swinging said second named bell cranks for raising and lowering through said operating connection'the rearward portion of said treating unit to vary its inclination about its forward pivotal mountmg.

HENRY C. HETTELSATER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS