US2371502A - Earth-moving machine - Google Patents

Description

Mix-ch 13, 1945. J. s. BURNS EARTH MOVING MACHINE Filed Dec. 6, 1943 2 Sheets-Sheet 1 March 13, 1945. 4 BURNS 2,371,502

EARTH MOVING MACHINE Filed Dec. -e, 1943 2 Sh'eets-S heet 2 Patented Mar. 13, 1945 g ED STATES.

a invention relates to earth' moving machines with more especial. reference to bulldozers, angledozers, trailbuilders' or bullgraders'in which an earthimoving blade is adjustably carried in front .of a self-propelled-vehicle: of crawler or tractor type. l ,1 Hitherto, machines of this character have employed a blade carriage comprising a-rigid andv massive yoke fulcrumed nearthe rear of the track. subframeand embracing the front of'the tractor, but in my co-pending applications Serial Nos. 393,819, 490,822 a blade carriage for. such machines is described comprising a parallel linkage extending longitudinally outside each trackv subframe, the lower links whereof are trunnioned .to the track subframes near the rear thereofand a front cross member carried bysaid linkages, adapted to .adjustthe depth of out without, changing the blade rake and camber from that to which it has been set, thus obviating structural and/or operationaldisadvantages of the known types of machine Moreover, inthe specific embodiment illustratedin my aforementioned application Serial No. 393,819, the fluid pressure cylinders, by which movementyof the carriage is effected, operate through bellicranks.

or rocking plate fulcrumed on the main frame of thetractor and operatively connected to the front cross member ofthe blade carriage by drop arms whereby it is unnecessary to compensate the fluid pressure system for oscillations of the track.

In some cases however, it may be considered desirable or necessary for the fluid pressure cylinders and their bell cranks or rocking plates operativelyconnected to the front cross member to be fulcrumed on the track-subframes instead of on'the main frame, and whenthe tracks oscillate due to the vehicle traversing ground inequalities, the symmetrical disposition ofthe operating mechanism and linkage is disturbedwithconsequent movement of the mouldboard and blade fromits adjusted position or stressing of the links and cylinder, mountings which is only partially relieved by the transference of the hydraulic medium from the cylinder at one side to that attheothen' f The present invention has for its object to provide compensating arrangements for such subframe mounted operating mechanism effectively to stabilise the blade and minimise stressing of the parts incidental to oscillation of the track subframes when traversing surface inequalities. Further and favourable objects willappear from the following description.

"Inaccordance with the present invention arrangements for compensating the effect of track oscillations on the' blade carriage operating plichanisms of bulldozers and angledozers comprise a swinginglinkage for each'bell crank or" rocking. plate of the carriage, e'a'ch linkage including an oscillating support on the track sub frame onwthe frontzofwhich support the bell crank is fulcrumedand-on the rear of which theloperating,mechanismjfor the bell crank is mounted, and a stabilizing link-for said support pivoted on an axisjfixed in-relation to the main frameythe, arrangement being. such that as the subframe rocks upwardlythe mounting of the operating mechanism is raised to an extent greater than the bell crank fulcrum so as to substantially retain the adjustedposition ofthe front end .ofthe bell crankiand thus of the blade.

Preferably the oscillating supports have their axes xfixed in relation to their respective. track subframes and are in the form of triangular plates having a pivot. or fulcrum at each of the threeapices, the firsticonstituting the axis about which. the support rocks while moving bodily in consonance with the movements of the track subframe, the second the joint with the aforementioned co-operating link, and the third forming afulcrum for the bell cranklever which opera-v tively connects, the piston-rod of the fluid pres-.

sur'ecylinder which is itself mounted on the support to the blade carriage. vBy this arrangement,

not onlyare the .fulcra of the operating bell cranks moved in consonance with their respective cylinderv fulcra when the tracks oscillate thus to effect compensation, but the additional advantage is obtained that the thrust of each fluid pressurecylinder between its own and, its bell crankcfulcrum .is taken by its rocking support without being transmitted'to the other parts of the machine and the necessity for providingcomplicatedvalve mechanism .in the fluid system is thusavoided. j i

As will-be:. ,understood, the-triangular 'supporting plates preferred may be replaced by a triangular assembly of links of appropriate section.

structural material, and in either case it may be foundconvenient for upwardly projecting bosses on the supports to be fumishedwhich serve as trunnions for the cylinders. 1 l

' The invention will be'further described with reference,-to the accompanying drawings which illustrate by way of example a specific embodiment fofrcompensating arrangement for an underslungblade carriage such as that described in which the compensation is effectedand journals 'of the fluid pressure partly in section, the upper half showing in plan the cylinder mounting the rocking plate and top link at the oil-side, and the lower half or sectional plan. view showing the lower. link. 111 crumed at the: rear: of; th straclcsubtramea.

The tractor'main frame is designated l and mounts the engine unit 2 and driver seat 3; while 4 and 5 are respectively the nearside and ofiside crawler tracks carried by subframes on so-called track frames 6 and]. which, when the; tractor is traversing ground inequalities, oscillate about a track frame pivotifii'n the former? ahorizontal axl borne at the rear of the tractor main frame I and which, in the tracton illus: trated, is co-incident with the axis of rotation on the; rear driving sprockets; 9 of the; crawlert-racksi lil represents: the leaf" spring of. the. track sus-- pension extending transversely from. onetrack frame II to the other 7 under theengine unitzt. Ill is the nearside front; idler, It are the sup:- porting wheels and 3 thefjockeywheekfm'thecrawler track l', all'. being mounted fionrotationinthe track subframe- 6'. These are standard featunes of the tractorwhich it will. be appreciated are illustrated: purely by way. at example and: as;- the invention is applicable to other types of: tractor, further detailed descriptioni of thepar ticularconstruction: of the tractor: itself is: unnecessarn except im so far as. its parts mount;- thev blade carriage;

Bolted? to: each of" the tracksubframesa It and T ar side platesl lfiextendingrf'rom the track frame pivot. 83 forwardlyalong: eachwsubl rame, and? welded to: each sideplate I 6. is a bearing bracket. l-L', forming an extension off the trackpivot. 8; upon which bracket or extensions: are mounted outside each track frame a. verticall post, W for" thenearside=. track 4, and" I9: for the-offside track: 5-, the. upper ends: of these posts being-welded to. or otherwise secured or: prevented? from. relative movement in relation to, the tractor main frame- I. In: the particular embodiment i'lius;-- trat'ed? the mounting posts It and; re; are each welded? or bolted tea depending, lip=2lr on afi'ange 2|! projecting.- from the: valance or fender 2-2: overltzing the rear of. the track, which: valance: is: a. conventional feature and, as will beappreciated; since the upper andzlower attachments of the; mounting posts t8: and t9. remain: fixed; in: relation; to. the. tractor: main frame- 17, they: arenot affected by the relative oscillation at the track:

frames 62 and. I permitted by the track suspension Hi When. traversingrunevensurfaces;

:llhe: mounting posts: I 8: and i9 each: carry: trun ni'ons: or journals: 2 55 and} 2E font-he upper and lower'side links: 2? and 28 f" a parallel linkage; the front vertical": links. 29 whereof'areaupstand ing portions at the endsof a front crossmember or transom 30. As shown more clearly in Ei'gt' 2 the transom: 3.0 is: V-ShfirDBii to permit angling or the moul'dboard and; blade which are; con

ventional form and are. designated bythe refer-- encesi3 l and 32"respectiive1y', theamoul'dboard hav ing 3:1).1'123 reana central bearing:braoketfliwhieh takes over: the front-apex offth'e transom SIT-and can be swung; about av hinge pin: 34: sov that. for: bulldozingthe mouldboardands blade are atri'ght; angles to the. longitudinal axis of: the.- tractor: as shown in the upper half oi 2;. while for angledozing the: mouldboamct and blademay: be inclined to:- either side-,, the-:lower;-halfof, Big; 2 showing the blade-set tor'angledoaing; to-the nearside. q

} Elachzmounting; nostl8; and. I8 similarly mounts a parallel linkage comprising an upper side link 21 and a lower side link 28 extending forwardly from its mounting post along the outside of the tracktor See the casemay. he. to the front vertical links. 29 upon which the front ends of the side links are pivoted at 35 and 36 respectively. 'onsequently, irrespective of the position of the vertical adjustment of the blade as set by the operatingmechanism hereafter described, its rake and camber remain unaltered throughout the range of adjustment as indicated by the in- I termpted outline A in Fig. 1 and as in the aforementioned: co-pending application Serial No. 393,819, but in contradistinction to the embodiment illustrated in that specification, owing to the lower link 28". being underslung in relation tothe track. subtrame; and the upper-and lower: side l'inks:.being; equidistantly spacedfrom. the axis of oscillation. of the tracks, i; e;, from: the track frame pivot: 6", notwithstanding the fact: that the upper links are in compression as'herea after explained, the cutting thrust is applied to thetra-ck subtrame at or below. the axis of oscillation thereby: counteracting or inhibiting any: tendency of the front end of the track; to: liftfirom the: ground, and thusensuring stabilityduring' the working: of. the machine. This improved blade: carriage forms: the subject of my application: Serial No. 490322" and with. such carriage, during normal working or with the; blade raised or lowered theblade thrust exercises: a clockwise moment: as viewed from the nearside (see Fig. 1 about the front pivotal connections 315i of the lower side links 28 and transom as 30 sothat the upper side links 21 are in com,-

pression and share such. thrust with the resultant advantage that the lower side links.- are comespondi-ngly relieved: of stress and may be of lighter: section; 4c The side links. 21 andizfl are advantageously of channel-section: and at their rearends; havewelded tolthem innerand outer eye-pieces 3:1: and? otstrip; respectively one on. each: side of their mounting on. the posts. t'B and I B so: that the crum. pins are im double shear:

3B is an. intermediate spacing link: bridging: the side links 21 and 28 approximately midway.- of their length forth -purpose of reducing any tendencyof the links? to whip or bend underex CESSiVI8= blade: thrust such: as may occur during, working: when the blade strikes, for instance-fa. treeroot or similar obstruction, and-40 aresta.-. bilizing rollers. carried by the lower links: 28 andri'din-gthe external vertical surfiaces of cheel'z plates- 4 mounted for the purpose on the track suhf-ra-mes near the front thereof so as totake the lateral thrusts applied to thebl'ade-carryingj structure, more particularly when angledozing;

At their front ends the sidelinksengage the pivot pins 3 and 36- carried by the uprights: 28 r at each one? of the transom 30', andprojecting outwardly from the base, of each upright or ver tidal-link 291s, agui'de channel 45: for the adjust; ing arms46 which are similar to, those described in the. aforementioned; (ac-pending application. Serial- 393,819; that is to say, their front ends.

ar pinned at. QT. to." brackets, 43 on. the mould board while along their length three holes are provided to be selectively'engagedby lbcking'pins is passing. through apertures; in the. guide. channels 4.5;jthe; central. holes. being. used. if the mouldboard; and blade. are to b set. for. bulldozing, as,

in, the upper. half or Fig. 2,, one irontg'and. one.

7 5 rear holeo'f "the respecti ejthrust. arms being.

used if the blade is to be set for angledozing as in the lower half of Fig. 2. I

For adjusting the depth of cut of the blade according to the present invention, track frame mounted fluid pressure cylinders 50 and including means compensating the effect of track oscillations are furnished. As illustrated the fluid pressure cylinder 50 and 5| are trunnioned at 52 and 53 on supports 54 and 55 bridging the respective tracks and carried by the track subframes 6 and 1. The supports 54 and 55 also provide fulcrums 56 for bell cranks or rocking plates 58 and 59 which extend forwardly and are connected by drop links 60 to webs 51 on the front cross member or transom 30. The rams or piston rods 6! and 62 of the fluid pressure cylinder are pivotally connected at 63 and 64 to the bell cranks 58 and 59, the arrangement being.

such as will be understood that when the ra ns 6i and 62 are pushed outwardly by the fluid pressure the bell cranks 58 and 59 are moved counterclockwise about their fulcrums 56 to lower the blade carriage, and conversely when.the ramsare moved rearwardly by the fluid pressure the bell cranks 58 and 59 move in a clockwise direction to lift the links 60 and thus raise the blade carriage, the maximum lifted positionbeing represented by the interrupted outline A in Fig. 1.

In order to compensate for unwanted variation from the set position of the blade such as results from oscillation of the tracks when traversing uneven surfaces where .the supports 53 and 54 are rigidly attached to the track frames 6 and I as conventional, the supports 54 and 55 are, .according to the invention, pivoted at 65 and 66 on the ide-plate I6 of their respective subframes which latter also carry inner plates 61 providing secondary bearings 68 and 69 respectively coaxial with the bearings 65 and 66.

1G and H are stabilising links for the'respective oscillating supports 54 and 55 and have their forward ends pivoted to such supports at 12 immediately below the trunnion 52 and 53 while their rear ends have pivots l3 and 14 on the tractor main frame I, and in the embodiment illustrated, carried by brackets and 15 forming a vertical continuation of the mounting ost l8.

In consequence of this arrangement, as will be seen more clearly from Fig. 1, when the near side track 4 encounters aground obstruction which causes it to oscillate about its track frame pivot 8 and take up the position represented by the dot and dash line B, instead of the fluid pressure cylinder 50 being moved bodily rearwardly and thus raising the blade from its adjustedposition, the support 54 being held by its stabilizing link 60 rocks about its pivot 55 in a counterclockwise direction resulting in a compensatory movement of the fulcrum 56 for the bell crank 58 so that the blade carriage remains set in its adjusted position in relation to the tractor main frame I, while as aforementioned the necessity of providing complicated transfer valve mechanism to permit the passage of the hydraulic medium from one cylinder to the other under these conditions is avoided. The lines Al, A2, A3, Bl; B2, B3, and Cl, C2, C3, indicate the corresponding positions of. the bell crank 58 in the normal, raised and lowered settings of the blade for the neutral and .extreme positions of the track. 4 when traversing ground inequalitie from which it will be appreciated that the mechanism is fully compensating and the blade setting is unaffected by track oscillations.

11 indicates the engine-driven pump of the fluid pressure system, 18 the container for oil or other hydraulic medium employed and 19 the control valve conveniently placed for manipulation by the operator from the seat 3 to raise or lower the mouldboard 3| and blade 32, to hold such blade in any adjusted position, or to leave it free to "fioat or ride over the surface of the ground.

What I claim is:

1. Apparatus for compensating the effect of track oscillations on the blade carriage operating mechanisms of bulldozers and angledozers having crawling tracks wherein the vertical position of the blade is adjusted through the medium of bellcranks mounted on the track subframes, comprising a swinging linkage for each bellcrank of the carriage, each linkage including an oscillating support on the track subframe on the front of which support the bell crank is fulcrumed and on the rear of which support the operating mechanism for the said bell crank is mounted and a stabilizing link for saidsupport pivoted on an axis fixed in relation to the main frame the arrangement being such that as the subframe rocks upwardly the mounting of the operating mechanism is raised to a greater extent than the bell crank fulcrum, so as to substantially retain the adjusted position of the front end of the bell crank and thus of the blade. 7

2. Apparatus according to claim 1 wherein the mechanism is fluid pressure operated and the fluid pressure cylinders are journalled, one on g each oscillating support, in such manner that as a subframe rocks upwardly the fulcrum of its cylinder is raised to an extent greater than the pivot of its oscillating support.

3. Apparatus according to claim 1 wherein the fixed pivots of the stabilizing links are located in the vertical plane of the axis about which the tracks-oscillate.

4. Apparatus according to claim 1 wherein the blade carriage is suspended from the front ends of the rocking plates by drop links.

5. Apparatus according to claim 1 wherein the blade carriage includes a front cross member mounted on pairs of parallel side links extending longitudinally outside the track subframes, and wherein said cross member is suspended from the front ends of the bellcranks whereby the raising of the blade carriage does not the angular position ofthe blade.

6. Apparatus according to claim 1 including fluid pressure cylinders wherein the supports are furnished with bosses about the pivots of the stabilizing links which erve as trunnions for the journals of the fluid pressure cylinders.

'7. Apparatus according to claim 1 whereineach oscillating support comprises an inverted yokeshaped plate the limbs whereof bridge the top of the track and have their lower ends supported by co-axial pivots borne by member attached to the track subframe.

8. Apparatus according to claim 1 wherein the oscillating supports comprise V-shaped side plates connected to a channel member the latter providing bearings for the bell crank and stabilizing link pivots.

affect JOHN STEPHEN BURNS.

Images