US2598685A - Material handling machine - Google Patents

Description

June 3, 1952 J. GREENLIEF 2,598,685

MATERIAL HANDLING MACHINE Filed Nov. 2, 1950 3 Sheets-Sheet 1 q Jiuper fireenlzlef. I

" .6 il 4 )Z 7 2.0

J1me 1952 J. GREENLIEF MATERIAL HANDLING MACHINE 3 Sheets-Sheet 2 Filed Nov. 2 1950 N @WN Jasper rean lief.

June 3, 1952 J GREENUEF 2,598,685

MATERIAL HANDLING MACHINE Filed Nov. 2, 1950 3 Sheets-Sheet s I .l v zw nfar: Jasper reenlief' Patented June 3, 1952 UNITED STATES PATENT OFFICE 9 Claims. 1

This invention relates to machines for handling material, or moving material from one location to another. The improvements are well-adapted for use for scraping earth to pro-,

vide a smooth or level surface, or for removing earth or other material from one location and then dumping the same at a second location which is beyond the place from which the material is picked, up by the apparatus.

Alsov the present structure may be utilized in.

digging excavations for buildings or the like, and when performing this type of work the machine is capable of operation in a manner to scrape off the side of an excavation for defining vertical or. upright surfaces.

Another advantage of the machine contemplated herein resides in the provision of a movable work frame or unit which is shiftable horizontally on a slidable carrier structure while performing certain of the before-mentioned operations. This work frame is provided with swingable masts and posts which remain inoperative during certain operations, and. by anchoring the free ends of a pair of masts or posts at predetermined locations on one of the other frames or. assemblies of the machine, the work frame may be operated to lift from the ground or a haymow, material such as loose or baled hay and raise the same. to a doorway or other entry into the loft of a barn or other farm building. This is particularly advantageous for loading silos, cribs and similar storage structures where the use of the present machine will save considerable labor and time for farmers.

A primary object. of the present invention to improve the operation of handling material by utilizing a manually controlled automatically operated mechanism thereby to substantially increase the usefulness of a tractor on which the mechanism is mounted and thereby multiply the customary facilities of such a vehicle.

Another object and advantage of the present improvements resides in the provision of a plurality of separately operated frames which are preferably superimposed the one upon the other and to operate each frame individually under the control of the driver of the tractor. In this connection it will. be understood that the driver rides on the tractor and by manipulating suitable controls he may perform numerous separate operations, each of which is distinct from the other. Differently stated, the frames are each operated independently of the others or a plurality of frames may beoperated atthe same time.

Further objects and advantages of these improvements comprises the provision of structurally separate frames or units carried by the chassis of a tractor, such frames being mounted one upon the other and each frame or unit bein capable of movement either independently of the other frame or movable simultaneously with one or more of said other frames. These units in the present instance comprise (first) a lower or base frame supported by the chassis and wheels of the tractor, (second) a slide frame operating in the guides on the base frame, and (third) a truss-shaped work-frame movable longitudinally in the guides on intermediate or slide frame, and having adjustability so that. it

is capable of being operated to raise its forward end region to a variety of positions of angularity thereby to perform a plurality of types of work at different distances above the ground level. The operation of these frames, separately or together, is at all times under the control of the operator who may manipulate. selective valves controlling fluid pressure which may be generated. by the motor of the tractor. The hydraulic operation of each frame is through the medium of cylinder and piston devices on the respective frames, and. in this connection the cylinder for operating one frame may be mount.- ed on the frame immediately beneath it and the forward end of the piston is connected to the superimposed frame which is being actuated; It will be understood of course that this particular arrangement may be reversed if desired.

Additional objects, aims and advantages of the improvements contemplated herein will be apparent to persons skilled in the art after the construction and operation of the material handling apparatus is' understood from the within description.

It is preferred to accomplish the numerous objects of these improvements and to practice the invention in substantially the manner hereinafter fully described and as more particularly pointed, out in the appended claims. Reference is now made to the accompanying drawings which form a part of this specification.

In the drawings:

Fig. 1 is a longitudinal side elevation of a material handling machine embodying the improvements contemplated herein, the machine being shown in use for example to movean earth engaging implement in a forward direction;

Fig. 2 is a top plan of the structure shown inFlg. 1;

Fig. 3 is a side elevation showing the machine Fig. showsthe manner of manipulating the Fig. fi'is a diagrammatic view showing a sche- The tractor or vehicle comprises an'elongate tudinal side sills I9 which are suitably reinforced by means of a plurality of oblique cross braces" The forward regions of side sills l0 are atadjusted tolift material from one location and 1 deposit such material ahead of the first position; 7 s

1 Fig. 4 shows the arrangements of the frames when raising the material and dumping the 1 same into a truck or lorry having a high body;

machine. for effecting a high lift in generally vertical direction to deposit the material in a loft, silojor crib; an

4 performing and elevating frame of a derrick-like structure that is movable longitudinally with the slide assembly B, and it is also adapted'for longitudinal movement independently of the slide frame assembly B.

The work frame and elevator assembly C has a pivotal or hinged connection with respect to the slide assembly B thereby permitting its forward end to be elevated or raised through the medium of. a: plurality: of pairs ofxlong levers and short 'posts 'each of which is pivotally carried by the assembly C. The free or swinging lower ends of the levers and posts may be selectively anchored to different portions of the other i chassis assemblywhich is characterized by longi- 1 structures beneath the assembly C whereby the derrick-likeassembly may be operated to elevateitsforward. end region to difierent levels tor through the medium of the'usual steering wheel "14 which is arranged forwardly from the operators. 'seat IS. .The 1 connections between the manually operated steering wheel 14 and the'front ground wheels of the chassis may take 1 f the form 'of any of the well-known steering or coupling mechanisms which may be adapted for mechanism and, the .power transmitting devices including the rear axle members to which the j largetraction wheels I8are connected orxjour- 3 nalled for'driving the tractor through the mediumof an'internal combustion engine [9. 1 the rear end of .the chassis assembly there is U-shaped anchoror'brace member 20, the side 1 arms of. which have their ends pivoted or f hingedly, connected with a convenient portion of 1 the chassis. to permit retraction of .said anchor 1 member when it is not functioning in the posij tion shown in the drawing. i

. In the interest of' clearness, the engine I 9,

the drivers seat I5 and the pilot or steering j wheel ld hav'e been omittedin portions of the drawings, particularly in Figs. 3 4 and 5 which j 1 have been somewhat simplified toshow the oper- 1 ating positions of the several material handling 1 assemblies of the'present structure towhich the improvements are directedj There'are preferably three structurally independent frame-like members or assemblies A, B,

; and C, .which are constructed and arranged so 1 thatthey are in cooperative association with 1 each other and are carried by the chassis frame- Q work'in superimposed relation the one upon the other and each frame being adapted to be pref- 1 erably guided by interengaged means whichopi eratively' connect the respective frames,

The lower assembly A, constituting a carrier 1 assembly or frame unit, has attachment with f portions of the chassispreferably at the front, and rear pillars l2 and 16 respectively, and the intermediate assembly B is defined by a'forwardly and rearwardly movable slide frame which is suitably guided in its movements-- on said carrier assembly A. The upper assembly C constitutes a truss-shaped or cantilever workabove "the ground; *Thus the material may be discharged or unloaded at a variety of heights, as for example, into a high body dump truck or lorry, or into. a storage space such as a barn loft, the top of a silo orfa' crib. The forward end of this work assembly C carries a suitable implement such asa scoop or shovel c which may be replaced by a bull-dozer member or any other suitable implement for performing a variety of types of work in connection with handling different kinds of material, Figs. 1, 3, .4 and 5 graphically illustratefa variety of positions which may be assumed by therespective frames in performing some. of thefmany types of work for which the apparatus is well-adapted. v

' Thev lower or carrier. assemblyA provides the means for guiding thesliding ttssemblyiBfj land are also anchored. The rear r'e'gionsbf these side pieces 30 project beyond the chassis as shown to provide'sufiicient overhang to accommodate hydraulic power cylinders 32. The rear,

ends of' side pieces 'gfiandcylindersn are con- 7 nected together by a coupling 33 and the forward end of theflcylinders- 32 are suitably at' tached to the pendent'ha'ngersii l carried by the chassis. The cylinders'are adapted to operate elongate pistons 35 which, attheir forward ends, are attached to straps 35 depending from the slide frame assembly B ifor moving the latter longitudinallyby means for pressure fluid in the cylinders 32. Conduitsjor pipes 3] connect the cylinders 32 witha suitable source of pressure fluid generated by a pump P driven byfengine IS. The cylinders32, pistons 35 and conduits 31 define a first fluid pressure power unit of the material,handlingapparatus. f Theintermedi'ate or sliding frame assembly 3 comprises longitudinal slide membersfiil, which are co-extensive with the side pieces 3110f assembly A, andat their rear portions rest on shim plates'33, on the top surfacesof saidside pieces '30. Cylinders El areconnectedat their rear ends to side members its. as by. means of strap couplings 42 and carry pistons 63 for actuating the work frame assemblyC in the man- .ner later to be' described. The side members 411 and cylinders M of assemblyB pass through the hangers '36 which. also function as abutments or stops against which the .widerstrap couplings 42 engage thereby limiting the forward movement of the slide frame assembly B as,will be understood. Intermediate the transverse planes of the :pillars l2 and It the side members 40 have guide collars 44 which extend downwardly so that their lower ends, which are angular, will engage in the guide channels 3| in the side pieces of assembly A thus to support thesid'e members and to permit of longitudinal movement of the-slide assembly, when the first power unit of the apparatus is energized. Thus it will be seen that the forward 'regionof the side members 40 may be extended a desirable distance in front of the chassis and the piloting ground wheels 13 of the tractor, asshown in Figs. 3, 4 and 5, during the performance of several of the types of work for which the apparatus is adapted. The cylindersare connected by conduits or pipes leading therefrom to feed pressure fluid there-- to from the pump P for actuatingthe pistons 43 of the second power unit of the apparatus. The forward ends-of pistons 43 areattached t0 fulcrum brackets 46 which travel along the side members 40 and have inwardly flanged or angular lower edges to extend beneath said side members between the latter and the upp r surfaces of side rails 39 of the supporting assemblyA.

The work performing assembly C which carries the implement comprises a pair of trusses whichare suitably connected together for operating in unison as a unit and having a pivotal or hinged connection as at 41 on the fulcrum brackets 46. Each truss comprises an elongate base or beam 50, an upstanding post 5| intermediate the ends of said beam, and a pair'of obliquerafters 52c and 5217 which are secured to the end regions of base beam 50 and extend upwardly therefrom to arch over the post 50 to which they are also attached. It will be seen that the forward regions of the beam 50 and front rafter 52b merge with each other to define downwardly and forwardly inclined arms 53 which are rigidly secured together by an X-shaped tie bracket 54 and extend oneachside of the implement c that is f-ulcrum'ed between said armsby trunnions c.;"""It will be understood that this'work frame assembly C, which is hinged at its rear endon fulcrum brackets 46 is thus adapted to have its forward end carrying the implement raised or elevated to a plurality of altitudes according to the work performedby the apparatus, and during material raising operations the implement, if it be a scoop as shown, is maintained in a level position.

'Thearrangement which is effective to raise the free forward portion of the truss work assembly C preferably takes the form of two pairs of elonate beams or booms 55 that are fulcrumed intermediate their ends as at 56 on the, crowns of the trusses at approximately the location of the posts 5|. The beams or booms are distributed so that there is a pair for each of the two trusses,

and the beams of a pair are positioned at opposite sides of its respective truss. The forward lower ends of'these beams 55 are adapted to be selectively attached by pivot bolts 55a, one of such locations being at a: at front ends of side members 40 of assembly B and another at y at the front ends of side pieces 30 of assembly A. Thus it is apparent that when the piston 43 ofthe second power unit is pushed outward the. fulcrum bracket 46 will force the trusses forwardly andpthe beam 55 will be effective to lift the free forward portion of the assembly 0 in. the manner suggested in Figs. 4 and 5. When lower elevation of the trusses is desired, the beams. 55 are released and carried free between the converging forward junctures of beams 50 and rafters 52b asshown in ings such an arrangement has been omitted Fig; 3.1 Under these conditions pairs oftshort posts 51, pivoted at their'upper ends onpins-EG: outside the beams 55 and the other or lower "ends.

been properly attached attheir lower ends .i'nithe selected locations, the work isperformed by ad mittingpressure fluid to cylinders 32 thus forcing the pistons 35 outward to move the slide assembly Band work assembly C in a forward direction sothat thescoop 0 will be filled with material.. The

cylinders 4 I "may then beactivated to effect move-n ment of pistons 43, whereby the work assembly-C is forced forward at its rear end-thus causing its forward end to be elevated 'by'the beam55 orthe post 51 depending ,upon which of these elements has previously been anchored at its lower'a-lend. After reaching the desired elevation the'scoop mayfbe tilted as shown inFig. 4 to dump the material. e

The means for manipulatingv the scoop com prise the upper extensions or arms fin' of the beams 55 beyond the pivots 56 so that they move:

with said beams, and link members 6| are con-;

nected at their rear ends tosaid arms by pivot bolts 62; The scoop C has upstanding fingers'fil that have hinged connections, by bolts '64,"with links 65. Intermediate links 61 and .65 there is a thirdpower unit which-is comprisedof hydrau lic cylinders 66 for operating pistons 6Twhich elements are connected a'tptheir ends to and are carried by the link membersfil and B5 respectively. As shown the cylinders receivepressure fluid" through pipes 68 leading from the pump P. When the cylinders 61 arefcharged with pressure fluid the tilting of thescoop-is effected, but :when

this third power unit is dormant the links-and the unit function as a rigid beam connecting the scoop to the arms 60 andthus'maintain the bottom of the scoop level at all timesduring the ele vation of the trusses of the work assembly 'C; It will be appreciated that any pressurefiuid arrangement which may be adapted for thepurpose can be employed for manipulating anindi-s vidual hydraulic power unit on each of therassemblies hereinbefore described; For the. purpose ofclarifying the several figures of the drawthereon. However, Fig; 6 shows in simple .diagrammatic form, a typical arrangement:- which is capable of activating a cylinder and piston power unit. As hereinbefore stated the internal combustion engine or motor I9 drives a pump 9. This pump may be of the gear type, blade type or 0th.- erwise as a matter of choice and convenience, and said pump receives the hydraulic fiuid'through "a suitable pipe 10 leading from a source such as a sump (not shown) into the inlet or suction side of the pump. The fluid under desirable pressure is lead from the compression sideof the pump by a discharge pipe'l-l to a three-way selector valve 12 having a handle that ismanipulated by the operator to a pluralityof operating positions. From the. control valve I 12 the pressure fiuid flows through a feed pipe 14 to a three-way coupling. '1, thence through a feed pipe extension 14a to therear end of cylinder X back of the pistons Y, to

move the latter outwardly and thereby shift-an assembly Z in a forward direction. When valve 12 is moved toanother position the fluid enters, I the forward ends of cylinders X through pipes.

two different positions for supplying pressure flu'idto the cylinder at one side of the piston and sump from the other side of the piston orvice ver'sai In a neutral'position'the spool-shaped valve body blocks the flow of pressure fluid to 1 both ends of the cylinder to prevent movement of j the piston. Valves of this type are generally well known in various arts and the same is not illustrated since the valve forms no portion of the f invention but is merely an accessory thereof. The valve I2 is adapted to shunt the pressure fluid through aby-pass conduit I5 leading back to the supply pipe ahead of the'pump P." Also, there f is a relief valve 12 interposed in a pipe 11 which 1 communicates at one endwith an intermediate portion of discharge pipe H and at its other end communicates with the by-pass pipe 15.

It will be-understood that the particular ar- There is of course'a similar arrangement for each of the three operating assemblies of the material 3 handling machine, and the respective control valves 'Il'are arranged adjacent each other in a 1 row within convenient reach of the operator. It 1 also will be understood that at least'the feed pipe 14 and its extensions 14a are of the flexible I hose type to permit movement thereof on or with the respective assemblies when the latter are 1 performing their functions and for this purpose there may be sufficient slack in said pipes to take 1 care of such contingencies.

14band-discharges in front of the pistonsYto 5 retract the same together with the assembly Z. i It will be understood that in either of its posil tions'the 'valve' 73 will dump the pressure fluid 5 from the inactive side of the piston into by-pass f pipe 15; Three-way selector valve 12 may be of 1 the spool type with'an open-center return to the i sump, the valve" body beingmovable to at least rangement shown in Fig.6 is merely typical of any convenient layout for the control of a power unit for operating an assembly of the apparatus.

While this invention has been described in de- 1 tall in its present form or embodiment, it will be j apparent to persons skilled in the art, after understanding the improvements, that various changes and modifications may be made therein What is claimed is: 1. A material handling apparatus comprising to said slide frame and the forward portions ex- 'ivotally connected intermediate its ends to'said ork' assembly, said lever having a normally free upper end beyond said pivot and connected to an jimplement pivoted at the forward end of said i a motor driven tractor chassis supported on front 3 and rear wheels; a carrierframe assembly havj ing'elongate side rails mounted on said chassis; 1 guide means on said rails; and a hydraulic cylinderand'piston alongside said carrier rails; a {slide frame having side rails above said carrier rails; angular 'straps'on said slide frame rails I interengaged with said guide means; means cou-' pling said slide frame to said carrier piston whereby forward and rearward reciprocal movements ;;are imparted to said slide frame; and a workperformingassembly'mounted on said slide frame for movement therewith and also adapted 'for' jangular movement independently thereof, said work assembly comprising a cantilever structure ther'ear portion of which is pivotally connected 5 tends beyond the front end of said slide frame j and is free for up and down movement to raise 1 lower an implement thereon; an elongate lever work frame for operating said implement, the lower other end of said lever being attachable at a plurality oflocations on the apparatus-to selectively predetermine the degree of elevation of the forward end of said work assembly; and power means for moving said work frame independently of said slide frame to elevate said implement.

2. Material handling apparatus mounted on the chassis of a power driven tractor comprising a slide frame guided for reciprocal longitudinal movement on said chassis; first manually controlled hydraulically actuated means/for selectively effecting said movement; a truss mounted for reciprocal longitudinal. movement on said slide-frame and also for longitudinal movement independentlythereof, saidtruss having arms extending forwardly beyond the front end of said slide frame and chassis and inclined in a generally downward'direction; pivot means at the rear end of said truss whereby the forward region thereof is adapted to be raised and lowered; a work implement pivotally carried by the terminal end regions of said arms; an elongate beam fulcrumed intermediate its ends on the upper,

reach of said truss and defining respectivelya short upper lever and a long lower strut; second manually controlled hydraulically actuated means operatively'connecting the end of said lever which is remote from its pivot to said pivoted Work implement; and means pivotally connecting the end region of said strut to selected fixed portions of,

movement; a truss mounted for reciprocal longi tudinal movement on said slide frame and also for longitudinal movement independently thereof, said truss having arms extending forwardly beyond the front end of said slide frame and chassis and inclined in a generally downward direction; straps depending from the rear ofsaid truss and engaged in said slide'frame channels; pivot means connecting the rear end of said truss to said straps to provid fulcrums whereby the forward region thereof is adapted to be raised and lowered, a work implement pivotally carried'by the terminalend regions of said arms;

an elongate beam fulcrumed intermediate its ends on the upper reach of said truss and defining respectively a short upper lever and a long lower strut; second manually controlled hydraulically actuated means operatively connecting the end of said lever which is remote from its pivot to said'pivotedwork implement; and means pivotally connecting the end region of said strut to selected fixed portions of the apparatus to effect a raising of said truss on 'its pivot during operation-of said first hydraulically actuated means,

said work implement being maintained in' non tilting position during said truss raising movement r i 4. Material handling apparatus mounted on the chassis of a power driven tractor comprising a slide" frame guided for reciprocal longitudinal movement on said chassis; first manually controlled pressure meansfor selectively effecting said movement; a truss fulcrumed at its rear end on said'slide' frame and adapted for reciprocal longitudinal movement on said slide frame, said ly carried by the forwardjregionof said truss; an elongate beam fulcrumed intermediateits'ends on the upper reach of said truss and definingrespectively a short upper lever member and a long lower strut; second manually controlled pressure means connecting the end of said lever which is beyond its fulcrum to. said pivoted work implement for tilting the same; means anchoring said strut to selected fixed portions of the apparatus to effect a raising of said truss on'its pivot; and third'manually controlled pre means moving the truss fulcrum in a forward direction thereby to progressively elevate the forward por- -tion 'ofsaid'truss to a desired level.

from said beams, inclined stays connecting the s end regions of said beams to the upper portions of said posts, said beams, posts and stays together defining a pair of laterally spaced trusses which are rigidly secured together for movement in a unitary assembly and being arranged with the forward portion overhanging the front of the chassis and mobile frame; means hingedly connecting the rear ends of said truss frames to said mobile frame; a work implement pivoted in said overhanging front portion of said truss assembly; and a plurality of manually controlled pressure fluid devices having cooperative association with said chassis, slide frame, unitary assembly and implement, one of said devices operative to bodily move said slide frame longitudinally with respect to said chassis, a second of said devices operative to move said unitary assembly longitudinally of said slide frame, and a third of said devices operative to control the position of said implement with respect to said unitary assembly.

6. Material handling means mounted on a wheeled vehicle chassis comprising a mobile frame guided for longitudinal reciprocal movement on said chassis; power means for selectively moving said frame; structure supported generally on said frame, said structure comprising elongate base beams extending longitudinally of the chassis above said mobile frame, posts extending perpendicular from said beams, inclined stays connecting the end regions of said beams to the upper portions of said posts, said beams, posts and stays together defining a pair of laterally spaced trusses which are rigidly secured together for movement in a unitary assembly and being arranged with the forward portion overhanging the front of the chassis and mobile frame; means hingedly connecting the rear ends of said truss frames to said mobile frame; a work implement pivoted in said overhanging front portion of said truss assembly; and a plurality of manually controlled cylinder and piston units for individually moving the several structures of the material handling means, one of said units operative to bodily move said slide frame longitudinally with respect to said and a work-performing chassis, a second of said'units operative to move said unitary assembly longitudinally of said slide frame, and athirdof said units operative tocontrol the position ofsaid implement with respect to said unitary assembly.

'7. Material handling means mounted on 'a wheeled vehicle chassis comprising a mobile frame guided for longitudinal reciprocal, movement on said chassis; powermeans for selectively moving' saidfram'e; and a work-performing structure supported generally on said frame, said structure comprising elongate basebeams' extending longitudinally of the chassis above said mobile frame, posts extending perpendicular from said beams, inclined stays connecting the end regions of said beams tothe upper portions of said posts, said beams, posts and stays together defining a pair of laterally spaced trusses which are rigidly secured together for movement in a unitary assembly and being arranged with the forward portion overhanging the front of the chassis andmobile frame; hinge means defining a fulcrum connecting the'rear ends of said truss frames to said mobile frame; a work implement pivoted in said overhanging front portion of said truss assembly; a plurality of manually controlled pressure fluid devices having cooperative association with said chassis, slide frame, unitary assembly and implement, each said device being elfective to move the structure to which the respective piston is connected; and elongate members defining a lever connected to said implement by one of said devices, and the other ends of said elongate members defining beams for securement to different portions of the structure to raise said unitary assembly on its pivot for effecting elevation of the forward region of said truss assembly to different angular relationship with respect to said truss fulcrum.

8. Material handling apparatus supported on a tractor, comprising parallel side rails fixed on and extending longitudinally of said tractor; hydraulic cylinders and pistons on said rails defining a first power unit for said apparatus; parallel slidable rails movable on said side rails by the actuation of said first power unit whereby the forward regions of said slide rails are extended a substantial distance ahead of said tractor; hydraulic cylinders and pistons carried by said slide rails defining a second power unit for said apparatus; fulcrum straps connected to said second power unit to be moved thereby longitudinally on said slide rails; a pair of parallel trusses of arch shape above said slide rails and connected to each other for simultaneous movement; pivot means hingedly connecting the rear ends of said trusses to said movable fulcrum straps whereby said trusses are movable in longitudinal directions, the forward regions of said trusses being free for up and down movement; elongate beams pivoted intermediate their ends at the crowns of said truss arches, and the lower ends of said beams having pivotal connection with selected portions of the apparatus for effecting the aforesaid up and down movement of the truss free ends to various selective levels; arms extending from the upper ends of said beams beyond the fulcrums thereof; an implement pivotally carried by the free ends of said trusses; and hydraulic cylinders and pistons defining a third power unit operatively connecting said arms to said implement for moving said implement independently of said trusses.

9. Material handling apparatus supported on a tractor, comprising parallel side rails fixed on and.

. 1 draulic cylinders and pistons carried by said slide 1 rails defining a second power unit for said apparatus; fulcrum straps connected to said second power unit to be moved thereby longitudinally on said slide rails; a pair of parallel trusses of arch shape above said slide rails and connected to each other for simultaneous movement; pivot means hingedly connecting the rear ends of said trusses to said movable fulcrum straps whereby said'trussesrare movable in longitudinal directions, the forward regions of said trusses being free for up and down movement; elongate beams pivotedintermediate their ends at the crowns of said f truss arches and defining inclined upper arms and inclined lower struts having free lower ends adapted for pivotal attachment in a plurality iof selected positions on portions of the apparatus 7 a for effecting the aforesaid up and down movement of the truss free ends to various predetermined levels; animplement pivotally carried by the free ends of said trusses; and hydraulic cylinders and pistons defining a third power unit operatively connecting said arms to said implement, said third power unit being effective in an inactive p condition to maintain said implementin a level plane and in an operative condition to tiltably move said implement to a dumping position.

JASPER GREENLJE REFERENCES cI'rEn The following references are of record in the file of this patent: o

UNITED STATES PATENTS Number Name Date,

958,911 Durkee V May 24,1 1910 1,623,194 Marshall 'Apr. 5, 1927' r 2,377,112 Strunk 1 May 29,1945 2,449,212 Fraga -Sept. 14, 1948 2,517,532 Lull Aug. 8, 1950

Images