US2113997A

US2113997A - Tractor

Info

Publication number: US2113997A
Application number: US727425A
Authority: US
Inventors: Oscar L Starr
Original assignee: Caterpillar Tractor Co
Current assignee: Caterpillar Inc
Priority date: 1934-05-25
Filing date: 1934-05-25
Publication date: 1938-04-12
Anticipated expiration: 1955-04-12

Description

o. L. STARR 2,113,997

TRACTORl Filed May 25, 1954 7 sheets-sheet 2 April 12', 193s.

O. L. STARR April 12, 1933.

TRACTOR l Filed May 25, 1934 7 Sheets-Shet eo. o@ @o A ATTORNEY April 12v, 1938. o. l.. sTARF 2,113,997

TRACTOR Filed May 25, 1934 7 Sheets-Sheet 4 A TTORN April 12,1938.

O. L STARR TRAqToR Filed May 25, 1934 7 sheets#sheen 5 A TTORNEY 'April l2, 1938. Q. L. sTAR TRACTOR 7 Sheetfs-Sheet 6 Filed May 25, 1934 Aww A ITORNEK l' April 12,1938. o L. STARR 2,113,997

- TRACTOR Filed May 25, 1934 7 sheets-sheet 7 Patented Apr. 12, 1938 4PATENT oFFicE TBAUI'OR bsoar L. sim, Mission sm Jose, com., aooignor to Caterpillar Tractor o., San Leandro, Calif., a. corporation of California Application Moy 25,1934, serial No. 127,425

Statement of invention The present invention relates to earth Working machines and more particularly to the provision of an integrally constructed, unitaryearth 5 working machine which is specially designed as a unit for bulldozing, trail building and the like work. The operation of trail building, perhaps, places the most vsevere requirements on a machine of this character and such operation will be discussed brieiiy to enable a better understanding of the instant invention. The term trail building is applied t0 the oper-ation of building roads or trails through mountainous or hilly country where none existed before.' In this work, the machine has only wooded, rocky hillsides before it, andmust leave behind it :a road suitable f or use'by any vehicle. y

In operation, the blade or tool is forced repeatedly intothe hillside to uprootrocks, brush and earth which, by turning the machine sharply, are cast downhill to form part of the roadway. To

accomplish such 'movement of the blade, the mamust be mounted securely as a unit with ther body, the mounting preferably providing for placing eitherend of the blade in leading position, and for easy adjustment thereof to operative or inoperative position. For bulldozing, the blade must be adjustable to a position normal to the longitudinal axis of the machine.

In machines of the character described, when an end of the blade is placed in leading position or, in other words, when the blade is disposed angularly with respect to the longitudinal axis of the machine, such leading end of the blade will be positioned further away from'the machine ground supporting member adjacent thereto than 40 the opposite or trailing end of the blade will' be positioned from' the other ground. supporting member of the machine. Thus, although the trailing blade end can be positioned relatively close to the ground support adjacent thereto, the leading end of the blade will be comparatively widely spaced from the other ground support adjacent thereto. A

As a result, when the machine is doing work, a disadvantageous leverage condition obtains adjacent Athe leading end of the blade because of the more widely spaced relationship of the leading end from the ground support adjacent thereto, which necessitates a longer lever arm con- '55 nection from the leading end to the body of the l 41 Claims. (Gl. 37-144) machine than from the ltrailing end to the body of the machine. I'he longer lever arm connection is less able to withstand working forces imposed on the leading end of the blade which bears the brunt of the work; and', consequently, the leadl5 ing end of the blade and the machine support adjacent thereto will tend to have an unstable Arelationship relative to the ground, this unstable relationship being obviously undesirable. Furthermore, in machines, such as track-type trac- 10 tors of the heavy type which are especially adapted for the described work, greater stresses will be'imposed on the groundI supporting means or track frame adjacent the more widely spaced leading end of the blade. i 15 vMy invention is designed to obviate the foregoing described disadvantages in present machines having an angular-ly disposed blade, by providing a machine in which the ground supporting members thereof are. spaced closely ad- 20' jacent both the leading and the trailing ends of the earth working blade. With suchfarrangement, the foregoing described disadvantageous leverage condition is avoided; and by having both ends of the-blade positioned closely adjacent the 25 vground supports of the machine, working forces are transmitted from the blade and through the ground supports to the ground, at a position close to the blade adjacent each endx thereof to thereby provide a stable support' adjacent both ends 30 of the blade.

It is an object of the invention, therefore, to provide an improved earth working machine in y which thrust forces imposed o n an angularly positioned earth working blade are transmitted to 35 the ground at positions closely adjacent both the trailing and the leading ends of the blade, to thereby provide a strong and sturdy machine.

Another object of the invention is to provide an earth working machine having ground sup- 40 ports longitudinally offset or displaced with respect to each other for accomplishing the foregoingv described object.

Another object of the invention is to provide an'earth working machine comprising'a track- 45 type tractor power unit and an angularly positioned blade unit, in which the similar or corre-- sponding blade ends of the. track mechanisms are both closely positioned' adjacent the blade, and

in which the tracks of the Vtrack mechanisms have ground contact closely adjacent the blade ends thereof to bring the ground support for the blade as close to the blade aspossible.

Another object of the inventlonis to'provlde an earth working an singularly4 55 Another'object of the invention is to provide,-`

as an article of manufacture, an improved integrally constructed, unitary earth Workingmachine characterized by the provision of a bulldozer blade forming an integral part of the machine.

Another object of the invention is to provide an improved earth working machine characterized by the provision of a 4bulldozer blade which is mounted closely-adjacent the ends of the ground-engaging supports for the machine.

Another object of the invention is to provide an improved earth working machine characterized by longitudinal displacement of similar ends of the ground-engaging supports therefor.

Another object of the invention is-to provide an improved earth working machine in which the body can be rigidly secured with respect tothe ground-engaging supports therefor.

Another object of the invention is to provide an improved earth Working machine which can be turned sharply and quickly.

Another object of the invention is to provide an improved earth Working machine which can be moved back and forth readily.

Another object of the invention is to provide an improved integrally constructed, unitary earth Working machine which has a traction unit and a blade unit, both of predesigned construction for cooperation to. provide a machine each part of which is specially designed for the work it must accomplish.

Another object of the invention is to provide an improved earth working machine of the track type, characterized bythe provision of endless track mechanisms which are adjustable with respect to the body of the machine. Y

Another object of the invention is to provide an improved earth working machine of the track type, characterized by the provision of a blade type, which is constructed to provide a high degree .of A stability against turning under the influence of side thrust applied to the blade.

Other objects will appear as the description Description of figures Fig. 6 is a plan view of a preferred type of ma` chine, with the upper stretches of the endless tracks omitted from the endless track mechanisms.

Fig. 6A is a continuation of Fig. 6.

' Fig. 7 is a left side elevation of the machine with a part of the endless track broken away.

Fig. Sis a fragmentary left side elevation of the lforces to the machine.

rear end of the tractor body and the final drive housing.

Fig. 9 is a sectional view taken inplanes indicated by the line 9-5 in Fig. 6.

Fig. l is a fragmentary sectional view taken in the plane indicated by the line Ill--I 0 in Fig. 7.

Fig. 11 is a transverse vertical sectional view taken in planes -indicated by the lines I, I in Fig. 8, the portion taken through the nal drive housing on line ||-I being rotated to coincide with the portion through the transmission case on line I I.

Fig. 12 is a fragmentary sectional view indicated by the line |2|2 in Fig. 8.

Fig. 13 is a schematic view illustrating the drive from the engine to the track mechanisms and power control mechanism.

Figs. 14 to 17 illustrate a second embodiment of the invention.

Fig. 14 is a plan view similar to Fig. 6.

Fig. 15 is a left side elevation similar to Fig. 7.

Fig. 16 is a sectional view taken in planes indicated by the line |6|6 in Fig. 1 4.

Fig. 1'1 is a fragmentary plan View indicated by the line in Fig. 16.

Fig. 18 is a schematic plan view illustrating a third embodiment of the invention.

Description of machine My invention is illustrated schematically in Figs. 1 through 5. The preferred machine has body 2| (Fig. 1). mounted on respective groundengaging supports.22, 23 in the form of endless track mechanisms, which have their similar ends longitudinally displaced. Earth working tool 24,l

in the form of a bulldozer blade, is securely mounted closely adjacent similar ends of

supports

22, 23, and is spaced substantially the same distance from each of said similar ends. In Fig. 2, supports' 22, 23 are shown in the adjusted position thereof with respect to body 2| which places the leading end of support 23 ahead of support 22. This adjustment serves to place the opposite end of blade 24 in leading position from that illustrated in Fig.

l. In Fig. 3, supports 22, 23 are adjusted with their ends in transverse alignment, to place blade 24 in a transverse bulldozing position. Fig. 5. illustrates my invention in a machine including body 25 supported on respective long and

short supports

26, 21 so that the similar ends thereof are longitudinally displaced. Blades 28, 29 are supported closely adjacent the ends of

supports

26, 21 to place opposite blade ends in leading position. i

Thus, my'invention includes bulldozing blade meansv extending transversely ofthe body of the machine, and arranged to provide either one of opposite operative angular positions thereof with respect to the longitudinal axis of the machine. It is to be noted that similar ends of the opposite` endless track mechanisms are spaced substantially the same distance from the blade means to provide for most eilicacinus transmission of bulldozing The machine includes generally, therefore, a traction unit/and a blade unit. Each of these unitsv is of predesigned construction for cooperation With the other to provide an integrally constructed, unitary earth working machine.

While my invention can be embodied in various forms, it will be described in connection with certain preferred embodiments having various features which I consider to be desirable.

In the embodiment of my invention illustrated.

in Figs. 6-13, body or main frame 2| (Figs. 6

' mounted on crankcase 3|;

' ing means 45 on top of the tween body-2| and and '1)y is supported on

endless track mechanisms

22, 23 by means .of respective pairs of crank` members movably provide for relative connected th longitudinal adjustment beeither or both of

respective track mechanisms

22, 23. By virtue of the pivotal connecting crank members, either of

track mechanisms

22, 23 is adjustable to place its front end ahead of the other. Also, the front ends of

track mechanisms

22, 23 are adjustable into transverse alignment.

Body 2| (Figs. 1, A6 and '1) includes crankcase 3| secured in a conventional manner to transmission case 32, thus forming the main frame of the machine. The source of vpower or engine is l and fuel tank 33 is positioned immediately rearwardly of the engine at the frontof the operators. compartment, the back of which is formed by seat 34 suitably mounted on case 32. The body or main frame is integrally constructed to provide for connection thereof to track

mechanisms

22, 23 in a manner later described.

Track mechanisms

22,23 are similar in construction and only one will be described in detail. Each endless track mechanism includes track roller or truck frame 4| (Figs. 6 and '1) having idler sprocket wheel yoke member 43. Yoke member 43 is slidably mounted on track lframe 4| and cooperates with suitable recoil mechanism, housed within shieldtruck frame and Within the hollow part of yoke member 43, to provide for yielding of idler sprocket 42 in the event the endless track becomes clogged. Adjacent the rear of track frame 4|, driving sprocket 44 is journaled in a manner described more specifically hereinafter. Endless track 46 passes around track frame 4| over respective idler and driving sprockets 42, 44. The weight of the machine is transmitted to the ground stretch of track 46 from trackframe 4| by track rollers 41; and the upper stretch of track 46 is supported by suitable track carrier rollers 48. AAs seen from inspection of Fig. '1, track 46 contacts the ground throughout the entire distance between the axes of front idler sprocket wheel 42 and rear driving sprocket wheel 44. Thus, the track contacts the ground adjacent the blade at a point as close as is practically possible, for the purpose previously explained. Also, because of the provision of a sprocket wheel for the idler 42, loa/d forces imposed on the front end of the track mechanism adjustment, means .is

` to the associated .track when the blade is doing work, are more ef-' ficaciously distributed.

Each endless track mechanism is m'ovablyv con-l nected to the body of the machine to .provide for relative end wise adjustment therebetween, so that similar ends of the opposite track mechanisms can be longitudinally displaced or transversely aligned. Means are provided for adjusting the movable connections by power from the engine; limiting means being provided to define -the limits of relative movement between the .track mechanisms and the body of the machine. After. provided to hold positively each track mechanism in the selected adjusted position thereof v 'v To accomplishvthe above purposes, spaced substantially parallel crank members each of which is pivotally connected at. its ends mechanism and to the body or main frame of rthe machine., -Crank member (Figs. 6 and '1) for track mechanism erebetween to 42 movably mounted adja' cent thefront end thereof by means of hollow are provided,

vhousing section 56.

23 has one end pivotally mounted in bearing bracket 52 rigidly secured on track frame 4| within hollow yoke member 43; the yoke member being provided with a suitable side opening 52 to permit entrance of the crank member end thercin. The other end of crank member 5| is pivotally mounted in outwardly extending boss 53 integral with crankcase 3|. Respective screws 54 extend through arcuate slotted portions of bossA 53 and bracket 52 and have threaded engagement with the ends of crank 5|, to prevent endwise movement thereof while permitting relative pivotal movement. The second crank member between track mechanism 23 and body 2| is in the form'of a housing crank which serves also to house a nal drive mechanism to sprocket 44, in addition to providing a s hiftable supporting connection between body 2| and track mechanism 23. j

Housing crank or member.55 (Fig. 11) comprises respective housing sections 56, 51, secured together by a plurality of screws 58. At its inner face, housing section 56 has annular flange. 59 engaging the outer face of wall 6| of case 32, and `also has lip 'or flange 62 which is journaled in a complementary recess in Wall-6|. To secure flange 59 against wall 6| and to providepivotal movement of housing member 55 about an axis located centrally with respect to iiange 59, a pairL of semi-circular cooperating collars 63 are provided; being secured towall 6| by cap screws 64. Collars 63 are recessed to fit over flange 59,

vthereby providing a journal for'flange 59 and and has an inner end ange 68A ,seated in a com- Y plementary recess in boss 61. As willlbe noted in Fig. 1l, housing section 56 is recessed at 66B between

bosses

61 and 66; theA shaft 68 being held against rotation by pin 68 passing through boss 61 and the shaft. At its outer ltapered end, shaft 68 is keyed within reduced outer end 69 of lbearing housing 10, which is described more specifically hereinafter. To connection thereof with shaft 68, track frame 4I (Fig. 6) has rear yoke member 1I rigidly secured thereon; and its spaced rear ends, comprising bracket 12 and arm 13, extend rearwardly and are pivotally connected at 14, 15 Aon reduced end 69 of housing 10 and on shaft 68 Within recess 68B (Figs. 6 and -11). The effective length of the crank arm length of housing 55 is equal to the effective crank arm length of crank member 5|, and the crank members are disposed in parallel relation.

Means are provided for limiting oscillation of the crank members 5| and 55 with respect to the body of the machine. `Adjacent crank member 5| (Figs. 6 and 7) boss 53 has longitudinal extensions 8|, 82,-providing spaced stops lying in the plane of and adapted for engagement with crank member 5| intermediate the pivotal connections thereof withbody 2| and track frame Upper collar 63 (Fig. 8) has spaced integral extensions 83, 84 which are adapted for engagement by apertured lug 86 (Figs. 8 and 12) on -Above and adjacent each of extensions 83, 84, collar 63 and transmission. case 50. provide for pivotal 9 is controlled by fork apertures 81 adapted to receive screw 88 to prevent relative movement between housing crank 55 and transmission case 32, as well as to provide a weight transmitting connection. When extension 86 is engaged with extension 83, as shown in Fig. 8, crank 5| (Fig. 7) is engaged with stop 82 and the crank members are thus maintained in their adjusted parallel relation. Upon oscillation of the crank members in a clockwise direction from the position illustrated in Fig. 7, by means later described, crank 5| will be engaged with stop 8|, and extension 86 (Fig. 8) will be engaged with extension 84. By this adjustment, endless track mechanism 23 is displaced forwardly with respect to body 2|. In each position of crank 55, it is xedly held by previously explained.

Endless track mechanism 22 (Fig. 6) is similarly provided with parallel crank members 9|, 92, similar in construction to crank members 5|, 55 vdescribed above. Hence, like reference characters have been applied to the correspond.- ing specic parts of the corresponding crank structures. The means for oscillating the respective crank members by power from the engine is described hereinafter.

In a preceding portion of the specification, it

was stated that rapid and easy reversibility is one of the desirable features in an earth working machine adapted for bulldozing, trail `building and like work. The power' transmitting means disclosed herein provides, in addition' to theusual clutch and change speed transmission, a reversibie transmission which is controllable by inde-l pendent means from the operators station. From the reversible transmission means, power is transmitted through respective steering clutches and final drive gears to driving sprockets 44.

The engine includes iiywheel |0| (Fig. 13) formingjpart of clutch |02 whose driven element |03 is connected to tubular shaft I 04. Shaft |04 has shiftable transmission gears |06 slidably and non-rotatably mounted thereon and adapted to be selectively meshed'with gears |01 on countershaft |08. Shaft |08 has bevel pinion |09 secured thereon at the rear end and meshing with opposite bevel gears III, ||2 (Figs. 11 and 13), which are journaled for rotation about drive shaft 4 byv suitable bushings and by respective bearings 6 in bearing cages I I1. Gears III, ||2 (Fig. 11) are provided on their innerfaces with clutchv teeth ||8 adapted forY engagement selectively with shiftable clutch element ||9 having splined engagement with annular clutch supporting extension of shaft I I4, so as to be rotatable with shaft |I4 but axially shiftable therealong.l As seen in Figs. 11 and 13, shifting movement of clutch element |I9-serves to establish a drive connection from one of gears ||2 to shaft II4. Shifting movement of clutch element |2| pivoted at |22 and having a pivotal connection with rod |23. Rod |23 is connected by a suitable linkage with reversing shift lever |24 (Figs. 6 and 7) adjacent operators seat 34. Forwardly of reversing shift lever |24, gear shift lever |26 is mounted for controlling the conventional change speed transmission gears |06, |01; while clutch lever |21 is provided for controlling clutch |02. I

From the foregoing description, it is seen that a drive can be transmitted to shaft ||4 (Fig. 11)

in either direction without operation of the conventional change speed transmission. This is very desirable as in a conventional change speed means including screw 88 as.

drives are provided for '44, through main Yclutch lever 2,113,997 32 are provided with respective aligned tapped transmission the gears are not arranged for rapid shifting from forward to reverse drive at any selected speed. From shaft I I4, drives are transmitted to respective driving sprockets 44 through similarly constructed steering clutches and nal drive gears. At its left end (Fig. .11), shaft |4 has drivingelement |3| of a conventional multiple disk steering clutch secured thereon; driven element |32 of the clutch being connected to the inner end of stub shaft |33 which is journaled in bearings |34 in housing section 56. As stated above, the construction of the steering clutch is conventional and is such that normally a driving connection is established thereby, which connection can be interrupted by operation of fork |36 (Fig. 11) movement ofY which conventional manner by steering clutch lever |31 (Figs. 6 and 7) at the operators station.

A similar drive, connected to the opposite end of cross shaft 4, is provided for driving sprocket 44 associated with track mechanism` 22.

Thus, it is seen that releasable andl reversible the driving sprockets of the endless track mechanism, which drives can be interrupted by disengagement of the respective steering clutches. For short turning, brake means |52 (Fig. 11) are associated in the usual manner with each driven element |32 of each steering clutch, whereby either track can be locked against movement. Respective brake mechanisms |52 are controlled by pedals |53 (Fig. 6) at the operators station.

'I'he above-described drive mechanism for driving track sprockets l44 also serves as means for adjusting ,

track mechanisms

22, 23 with respect to body 2| when desired. The adjustment of lefthand track mechanism 23 from the position shown in Fig. 2 to that described as an illustrative example. 1 To condition the machine for adjustment of track mechanism 23, the right-hand steering clutch associated with right-hand track mechanism 22 is released by adjusting right-hand control lever 'I 31; and the brake associated with the `right-hand steering clutch is applied by depressing righthand pedal |53. Thus, right-hand track mechanism 22 is locked against movement. Screw 88 is removed to enable free pivotal movement of crank housing 55. 'After the machine is conditioned as described above, theupower transmitting means is applied to the left-hand sprocket |21, gear shift lever and reversing shift lever |24, to drive left-hand sprocket 44 reversely, i. e., in a clockwise direction as viewed in Fig. 7. Normally with housing crank 55 locked byscrew 88, such operation would result in turning of the machine; and locked track mechanism 22 would be twisted on the ground. However, as housing crank 55 is free is controlled in a shown in Fig. 1 will be to 'pivot by virtue of 'the removal of i screw 86, pinion 4| (Fig. 11) (which always rotates in the sameJ direction as sprocket 44 and is-coaxial with the pivotal connection between crank 55 cand .transmission case ,32) in rotating causes not only axial, but also translational rotation of gear |42, pinion |45, gear |46 and sprocket 44. Thus, housing crank 55 is rotated in a counter-clockwise direction from'the position illustrated in Fig. 2, to that shown in Figs. 1, '7 and 8, the entire machine being laterally tilted to the right as track mechanism 23 moves rearwardly. In effect, the nal drive mechanism operates as epicyclic gearing, pinion |4| acting as the sun pinion having a xed axis, crank housing 55 actlng as the planet carrier, sprocket 44 acting as the planet pinion, and endless track 46 acting asl the xed ring gear. When body or main frame 2| is descending from its highest lifted position after crank members 5| and 55 are vertical during 'the track mechanism shifting operation, the same rate of movement obtains as existed when the body was being elevated, because the engine acts as a brake against. any .acceleration of body movement. contacts stop extension 63, the operator disengages main clutch |62; and screw 88 is again inserted in position to lock housing to 'the main frame of the machine." If the clutch is not disengaged when stop extension 63 is contacted, no

damage can occur as the drive is simply transferred to sprocket 44 and the machine will start From the preceding description of the track mechanism 'shifting operation, the manner in which such mechanisms can be shifted to assume the positions shown in Figs. l1 through 3, will be apparent; it being obvious that each track mechanism'is capable of forward and backward shifting dependinguponv its initial position relative tothemainframe2|.

Bulldozing. blade means is adiustably mounted at the front end of the machine by thrust frames movably connected thereto and to track frames 4|. The connections include' shock absorbing means to prevent breakage of the parts, and to compensate wfor endwise movement of lthe blade during adjustment of the angular-position thereof lwith respect to the longitudinal axis of the Lmachine, which angular adjustment is accomplished by relative: shifting of the track mecha- Blade (Figs.

6,7. and 9) is of conventional construction `per se.` Bracing angle |6| (Figs. 6 and 9) is secured by welding to blade 24 adjacent the cutting edge thereof; and adjacent the -ends of angle |6| and vertically spaced therefrom, brackets |62 are secured to blade 24. To provide forconnection of each end of blade 24 to the associated track frame 4|, each bracket |62 (Fig. 9) and angle |6| are apertured to receive pin |63'passing therethrough and through apertured boss |64 formed centrally of transversely extending crank member |66 (Fig. 6); a crank member |66 Being associatedwith each track frame 4|. '=`At its outer end, 'each crank member |66 has one crank arm pivotally connected by pin |61 to thrust member |68, extending rearwardly therefrom and pivotally connected about a horizontal axis at |69 to yoke member 1| en After housing extension 66L tion shown. l

brackets |63, |64 onassociated track frame 4|.

Guide means are provided on each track framey 4| for absorbing side stresses from the thrust frames, in any vertically adjusted positions thereof, to thus brace the blade 24 against lateral movement. The outer face of each yoke member 43 (Figs. 6, '1 and' 10) has upwardly extending brace |66 secured thereto to provide a mounting for guide plate |69 secured to the upper end of brace |66 and extending downwardly therefrom. 'Ihe lower end of guide plate |69 is slidably disposed between guide and thrust brackets |96 secured on track frame/4|, and the thrust member |66 associated therewitnf The-thrust frames also provide compensation for the change in the effective width of blade 24 with respect to track frames 4| when

endless track mechanisms

22, 23 are adjustedlongitudinally with respect to body 2|. The various conditions are illustrated schematically in Figs. 1 through 3; and in discussing these ilg'ures, reference to the' right-hand and left-hand thrust frames will be made as looking from the operators seat. The width between pins |63 (Fig. 3)

is selected so that with blade 24 in the position shown, both sets of telescopic members |16, |19 are expanded by the springs compressed therein. When blade 24 is adjusted with its lright end in leading position, bymoving endless track mechanism 22 forwardly with respect to body 2|, as illustrated in'lFig. l, the eifective lateral width between pins |63 has been shortened so that crank members |66 are oscillated to compress both sets of telescopic members |18, |19; right-hand members |18, |19 being substantially fully compressed. This results in a slight inward thrust on telescopic members |18, |19 which is accommodated by the pivotal connections |86 at their rear ends. In Fig. 2, the left end of blade 24 is placed in leading position so that left-hand telescopic members mil than right-hand thrust frames, has a pivotal floating connection with the track mechanisms at'another apex, and

' is pivotally connected at its third apex to a telefor adjustment with respect thereto byv means operated from the engine.

At the inner end thereof, each crank member |66 (Figs. 6 and 9) has vertically apertured boss |9| in which upwardly extending fork |92 is pivotally received. Fork- |92 (Fig. 9) is pivotally connected by pin |93 to an apex of triangular lift crank |94. Each lift crank |94 at its rear apex terminates in integral transverse pin |96 pivotally ani slidably received in slot |91 formed in extension |98 of pivotally mounted bracket |8|. At its upper apex, lift crank |94 (Fig. 7) has fork 20|, mounted therein and pivotally connected by pin 202 to shaft 203. Shaft 203 extends rearwardly along body 2| and is telescopically received within tubular shaft 204 having ball and socket connection 206 .(Flg. 6) at its rear end with transverse lift member 201. Shafts 203 are provided with a pluralityl of longitudinally spaced vertical apertures 2| adapted to be aligned with elongated, longitudinally extending apertures 2 2 in tubular shaft 204. Pin 2|3 is placed through apertures 2| 2 and one of apertures 2|| to maintain the telescopically adjusted position of

shafts

203, 204. By placing pins 2|3 in proper relation with elongated apertures 2|2 of tubular shaft 204 and selected aperture 2| Iof shaft 203, the combined effective lengths of

shafts

203, 204 are adjustable in accordance with the longitudinally adjusted positions of

track mechanisms

22, 23 with respect to body or main frame 2| Elongated apertures 2|2 provide for slight relative movement between shafts 2 03, 204 when telescopic housing members |18, |19 yield in acting as shock absorbing means. l

Transverse lift member-201 (Figs. 6 and 8) has opposite longitudinally apertured brackets 2|6 secured thereon, which are slidably engaged with guide rods 2|1 fixedly mounted by brackets 2|8 on case 32 of body 2|. Centrally of transverse lift member 201 (Fig. 6), nutmember 22| is'secured thereto by means of bolts 222. Nut inem--l ber 22| has threaded engagement with screw member 223 which extends rearwardly therethrough within tubular housing 224 (Figs. 6 and drive for driving sprockets 44. To prevent the entry of deleterious matter while providing for longitudinal movement of nut member 22|, flex-` ible bellows 226' (Fig. 6) is provided around screw member 223 between nut member 22| and body 2|.

The reversible clutch means for rotating screw 223 includes opposed clutch teeth 23| (Fig. 13,)

on

respective bevel gears

232, 233, which are c011- Such lift means includes opposite triangular' nected by idler bevel gear 234. Bevel gear 232 is suitably keyed on screw member 223 for rotation therewith; while bevel gear 233 is journaled about shaft 236 which has a reduced end thereof journaled in a suitable end recess in screw member 223. Between

bevel gears

232, 233, shaft 236 has splined portion 231, upon which double faced clutch element 238 is slidably and non-rotatably mounted. Clutch element 238 has clutch teeth at its-ends adapted to mesh with respective clutch teeth 23| on

bevel gears

232, 233, and is con. trolled by fork 24| mountedon shiftable shaft 242. Shaft 242 has rack 243 engaged by pinion 244 on control shaft 246 having operating handle 241 secured thereto. As seen in Fig. 6, handle 241 is located adjacent the operators station immediately in front of seat 34. Shaft 236 (Fig. 13) extends forwardly through tubular clutch driven shaft |04, and has splined connection 248 with flywheel at its-front end.

Thus', by manipulation of handle 241, a selective drive in eit-her direction can be imparted to screw member 223, to adjust nut member 22| longitudinally thereof inv either direction. 4Longitudinal movement of nut member 22| adjusts transverse lift member 201 along guide rods or shafts 2| 1; and through respective

connections comprising shafts

203, 204, movement of lift member 201 effects oscillation of respective vtriangular'crank members |94 about an axis determined by the position of shiftable pins |96. Such movement o f the crank members |94 adjusts the front ends of the thrustl frames, comprising crank members |66, thrust members |68 and the telescopic connections |18, |19, to adjust blade 24. In Fig. 4 the maximum lifted position of blade 24 is illustrated in solid lines; it being seen that each pin |96 is at the forward end of slot |91, and that telescopic members |18, |19 are extended. The phantom line position of blade 24 in Fig. 4. illustrates one of the lowest positions thereof. In such low positions, another of which is illustrated in Fig. 9, pins |96 are adjacent the rear ends of slots |91, and the telescopic connections are compressed.

It will be observed, from the preceding de scription of the preferred type of machine, that because the track mechanisms are positionable With their similar blade ends displaced or offset longitudinally with respectto each other, land relative't'o the body of the machine, the blade when operating at an angle as illustrated in Figs. 1 and 2 is positioned the same' distance away from the similar ends of both of the track mechanisms, to enable both ends of the blade to be supported by the track mechanisms closely adjacent to .the blade to provide for stabilization and eflicient bracing .of the blade at both ends thereof. u Also, because of front crank arms 5| and 9|, lateral spreading of the track frames '4| is obviated to cooperate in providing a sturdy machine.

Figs. 14 through 17 illustrate a second embodiment of the invention which is similar in many yrespects. to that illustrated in Figs. 6 through 13.

In the second embodiment of my invention, body 2| of the machine is constructedvto provide unimpeded vision for the operator, in manipulating the blade. To accomplish this purpose, the power plant is positioned at the rear of the machine, Iand the operators station is located forwardly of the power plant immediately behind the blade. In addition, the power'plant construction provides a relatively low center of gravity for the machine.

The power plant (Fig. 15) jincludes engine .structure 25| which has its rear end supported 4 v tween the thrust frames and the blade upon scribed in detail.

on and rigidly secured by bolts 252. to transmission case 253 positioned below the engine structure,v and is secured at its i'ront-endby suitable bolts to clutch housing 254. Clutch housing 254 extends downwardly from engine 25| and has integral rearwardly extending tubular portion 255 secured by suitable cap screws Y2515 .to the iront of the transmission case 253. The front of clutch housing 254 is closed by cover 251. Thus, gengine 25|, transmission case 253, clutch housing 254 and tubular portion 255 provide the main frame of the machine. Forwardly of engine 25| and suitably supported on the power plant, framework 25| is provided, for supportying operator's seat 252 and various control members' described hereinafter. Rearwardly of trans- .mission housing 253, steering clutch housing 255 (Fig. 14) is secured thereto, having bell, extensions 259 at each end for connection to the final drive housings.

Endless track mechanisms, similar to track

mechanisms

22, 23 described above, are employed and will, consequently, not be described in detail. The connections between the endless track mechanisms andthe body or main frame are similar to those'alre'ady described, and comprise front crank members 255 and rear housing cranks 251 similar, respectively, to crank members 5|, 9| and housing cranks 55 described above. Respective crank members 255 have their inner ends pivotally `received in bracket 255 (Fig. 15) secured, by suitable screws, across the front of cover 251.- Bracket 255 has integral longitudinal extensions 25.9 at its ends providing stops for" cranks255, similar to those described above. Cranks 251 are journaled on bell extensions 259 in the same manner 'that cranks 55 are journaled on'transmission case 432 as described above..

and are similarly connected to yoke members 215 of track 4frames 4|.

Adjustment of the track mechanisms with re- .spect to the main frame or body is identical to that described in connection with the first embodiment'of my invention, and 'will not be de- Blade 24 is connected adjacent its ends to U- shaped thrust frames embracing

endless track mechanisms

22, 23, and pivotally connected.

thereto. The connections from blade 24'to the thrust -frames `include means for varying the angle of blade 24 with respect to the ground, andy means compensating for thechange in effective width of blade 24 upon longitudinal adjustment of .track mechanisms 22, `23 with respect to the main frame or body. Bracing angle |5| (Figs. 14 and 16) on blade 24 has pairs of spaced brackets 215 secured thereon. pivotally receiving pins 211 passing through bosses 215 in connection-brackets 219. Each bracket 219 is provided with upward extension 25| apertured tozreceive. clamping bolt 252- passing through lslot 253 in link 254. Link 254 is pivotally connected to blade 2'4 by pin 285 ,Journaled in brackets 251. `lBy looseningbolts 252, links 254 can be adjusted with respect to' extensions 25| to oscillate blade 24 about the axis of pins 211, thus varying the angular position of blade 24 with respect .to` the ground.

Each bracket 219 (Figs. 16 and 1'1) has vertically spaced, rearwardly extending anges 29|. providedwith transverse slots 292. Slots 292 pro'- vide a sliding mounting for a gear mounted on the ends ofthe thrust frames, and meshing with a lrack between flanges 29| of each bracket 219 to provide for relative transverse movement beangular adjustment of the blade. Gear 295 is journaled on shaft 291 mounted in vertically spaced extensions of bracket 295 on each thrust frame 299. Each shaft 291 has reduced ends,

provided with rollers 35| cotter-held thereon and disposed in slots 292. Gear 295 meshes with rack 352 welded on bracket `219 between flanges 29| thereof.. To maintain theadjusted position of gear 295 with respect to rack 352, block 353 is provided, having teeth adapted to engage gear 2.95 toform a wedgebetween gear 295 and rack 352. Block 353, is'held in position by bolt 351i.`

In an angled transverse position of blade 24 with respect to the body,- i. e., as shown in Fig.

14, respective gears 295 are engaged with the outer portions of racks 352; and rollers 35| arepengaged with the outer ends of slots 292. With blocks 353 removed and the blade adjusted from the angled position shown in Fig. 14 to the `opfpositely angled position, gears 295 travelinwardly along racks 352 and then. outwardly again to the outer end thereof. If blade 24 is ad- `iusted to its transverse position 'at' right angles to the longitudinal axis of the machine, gears.

295 .remain engaged with the inne'r ends of racks 352, and rollers 35| are engaged with the inner ends of slots 292. In this position, blocks 353 are disposed to the outside of gears 295'; pins 354 being disposed in the outer set of apertures 355 l (Fig. 14).

'I'hrust frames 299 are U-shaped and extend rearwardly around

track mechanisms

22, 23, and

are pivoted by pins 3|| to respective yoke members 215 rigidly secured to track frames 4i. l

Lift means are provided on,

endless track mechanisms

22, 23 for adjusting blade 24 vertically with respect to the ground. Each thrust frame; 299 (Fig. 16) has ball and socket connection 3|5 with lift'screw 3|1 (Flgs. .15 and 16), which extends upwardly within housing 3|5 and has threaded engagement with a suitable nut member mountedin housing 3|5. Housing 3|5 is pivotally mounted by opposed trunnions 3|9 in fork 325 secured between the upper converging ends of support beams 32|. Beams 32| extend rearwardly and then downwardly, and are connected 'by suitablescrews to brackets 322 on the opposite sides o'f the track frame 4| associated therewith. It will be observed that the side mem'- bers of thrust frames 299'are positioned between y 'the sides of the track frames 4|, and beams 32|..

Hence, beams 32| also serve to absorb transverse .-.thrusts imposed on thrust frames 299.' The nut members in housings 3|5 4are operated by telescopic shafts 325 (Figs. 14 and 15) from a suitable reversible clutch mechanism in gear box 321, controlled by hand lever 328. Such clutch mechanism in gear box 321 is operated from engine 25| by a suitable drive connection including shaft 329 -(Fig. 15). Itis to be noted that the drive connection extends'forwardly from the power plant and then upwardly to the gear box, providing a very simple structure. Shaft 329 is driven from engine 25| similarly to the constantly running drive .for the power control means disclosed in the first described embodiment of the invention. y

18 illustrates more or less schematically a third embodiment of the invention. In this embodiment. thebody of the machine is'supported by rigid connections on opposite non-adjustable endless track mechanisms of .different lengths. Oppositely angled bulldozing blades a're mechanisms having similar ends longitudinally Body 25 includes engine 35| at one end, and

seat 352 at the other end which faces toward the side of the machine supported on the long track mechanism. Also, body 25 is supported at one end on long track mechanism 26 and short track mechanism 21, by transverse member 356; and

at the other end, body 25 is supported by respective nal drive

housings

351, 358. The track mechanisms are similar in construction, except as to dimensions, with those described above, and are controlled through similar transmission and iinal drive means, through gear shift lever 36|, main clutch lever 362, reversing shift lever 365, steering clutch levers 363 and brake pedals 364.

.Respective bulldozing vblades 28,` 29 are pivctally connected about vertical axes to respective long and short thrust members 313, 314, by brackets 315. Thrust members 313 and 314 have commonaligned transverse pivotal connections with track mechanisms' 26, 21, on pins 311. Blade 28 and lift mechanisms 318 therefor are supported by beams 319 similar to those shown in Figs. 14 and 15. Lift mechanisms 318 (Fig. 18) are 0pcrated through telescopic shafting, by reversible clutch means in gear box 38|, controlled by hand lever 382. Blade 29 is connected to lift mechanisms 318 on suitable brackets '383, 384, and

operated through telescopic shafting by reversible clutch means in gear box 38| controlled by hand lever 382. It is to be noted that the controls are conveniently disposed around side seat 352 which is disposed facing long track mechanism 26, so that the operator can see the leading end of either blade while seated.

Although in the modification of Fig. 18 bulldozing blades 28 and 28 are notangularly adjustable, it willbe observed that because they are oppcsitely angled at the ends of the machine and because themachine can be driven forwardly and rearwardly, either one ofthe blades can be employed to obtain the eiect of a single angularly adjustable blade.

I, therefore, claim as my invention:

1. An earth working machine adapted for use in bulldozing, trail building and like Work; said machine including a body; opposite endless track mechanisms supporting said body; said track displaced; bulldozing blade means; thrust transmitting means spacing said blade means substantially equal distances from said similar ends of said track mechanisms; means for adjusting said blade means to different heights relative to said body; a source of power on said body; and

means for driving said track mechanisms from J lbody; said supports having similar ends longitudinally displaced; bulldozing blade means adjacent said similar ends; thrust transmitting means spacing said blade means substantiallyequal distances from said similar ends; means forvadjusting said blade means to different heights relative to said body; a source of power on said body; and

means for driving'said supports from said source of power.

. 3. An earth working machine adapted for use in bulldozing, trail building, and like work, said machine having a body, spaced ground-engaging supports for propelling and supporting said body, and a bulldozer blade adjacent one end of said body extending transversely thereof and disposed at an oblique angle with respect to the longitudinal axis of the machine, said supports adjacent said one end of said body having ends offset longitudinally with respect to each other.

4.. An earth working machine adapted for use in bulldozing, trail building and like Work, said machine having a body, oppositeV endless track mechanisms connected to said body, said track mechanisms having similar ends longitudinally displaced, bulldozing blade means extending transversely of said body adjacent said similar closely adjacent said similar ends.

6. An earth Working machine adapted for use in bulldozing, trail building and like work, said machinehaving a body, opposite endless track mechanisms connected .to said body, and bulldozing blade means connected to said track mechanisms and spaced substantially the same distance from similar ends thereof, said track mechanisms being connected to said body for relative adjustment with. respect thereto to vary the angular position of said blade means relative to said body.

7. In an earth Working machine adapted for use in bulldozing, trail building and like Work, a body, opposite endless track mechanisms, and` means connecting asid track mechanisms to said body for adjustment relative to said body to dispose similar ends of said track mechanisms in longitudinally'displaced position.-

8. In an earth working machine, a body, and Opposite endless track mechanisms movably connected thereto for endwise displacement to dispose similar ends thereof in longitudinallydisplaced relation.

9. In an earth working machine, a body, and

vground-engaging supporting means therefor including an endless track mechanism movably connected thereto for relative endwise displacement.

10. In an earth working machine, a body, and

opposite endless track mechanisms movably connected thereto for endwise displacement to dispose similar ends thereof in longitudinally displaced relation, the connections between said -body and said track mechanisms allowing the placing of either of said similar'ends in leading position.

11. In an earth working machine, a body, opposite endless track mechanisms, adjustable means supporting said body on said track mechanisms to allow relative endwise displacement therebetween, and means for adjusting said supporting means to place similar ends of said track mechanisms in longitudinally displaced relation.

12. In -an earth working machine, a body, opposite endless track mechanisms, adjustable means supporting said body on said track mechanisms to allow relative endwise displacement therebedii lcc

arrasar means in a selected adjusted condition thereof to maintain the corresponding relatively adjusted positions of said body and said track mechanism.

13. In a machine of the class described, a body, opposite endless track mechanisms, and means connecting said body to each of said track mechanisms, each' connecting means "comprising spaced parallel cranks movably connected to said body at one end and to the associated track mechanism at the other.

1d. 1n a machine oi the class described, a body, opposite endless track mechanisms, means connecting said body to said track mechanisms, each connecting means comprising spaced parallel cranks movablyy connected to said body at one end and to the associated track mechanism at the other, and driving means for said track mechanisms., one of said cranks of each connect-- ing means providing a housing for a part of said driving means.`

15.1n an earth working machine;l a body; opposite endlesstrack mechanisms; each track mechanism including a track frame, anl idler wheel adjacent one end of said frame, a driving sprocket wheel adjacent the opposite end of said frame, and an endless track extending around said wheels; and connecting means between each track frame and said body, including a crank movably connected at its ends to the associated frame and said body adjacent said one end of i said frame, and a. housing crank'pivo-tally connected at its ends to the associated frame and said body adjacent said opposite end oi said frame.- l

16. In an earth working machine; a body; opposite endless trackmechanisms; each track mechanism includingva track frame, an idler wheel adjacent one end of said frame, a driving sprocket wheel adjacent the oppositeend of said frame, and an endless track extending around said wheels; connecting means between each track frame and said body, including a crank pivotally connected at its ends to the associated.

frame and said body adjacent said one end of said fram and a housing crank pivotally connected-at its ends to the associated frame and said body adjacent thesaid opposite end of said frame; and means for limiting oscillation of said cranks and housing cranks with respect to said body.

i7. in an earth working machine adapted for use in bulldozing, trail building and like work, a body, opposite vground-engaging supports connected to said body for relative endwise movement with respect thereto, similar ends of said supports being longitudinally displaced with respect to each other, transmission means in said body for driving said supports, and means for conditioning said supports to provide for'endwise movement thereof upon establishing a drive through said transmission means. 4

18. ln an earth working machine adaptedfor use in bulldozing, trail building and like work, a body, ground-engaging supports connected to said body lfor relative endwise movement with respect thereto, and power-operated means for causing such movement.

19. 1n an earth working machine adapted for use in bulldozing, trail building and like Work,

a body, including a ysource of power, oppositey endless track `mechanisms connected to said body for endwise movement with respect thereto, and selectively operable means connected to said source of power` for causing such movement.'

20. An earth working machine adapted for use in bulldozing, trail building and like work; comprising a traction unit including a body, `havingl a source of power, and opposite 'endless track mechanisms movably connected thereto for relative endwise adjustment; said mechanisms being adjustable'to position similar ends thereof in longitudinally displaced relation with either of said similar ends in leading position -or to position said ends in lateral alignment; and a blade unit including a blade, thrust means connected to said blade adjacent the ends thereof and con- D nected to said endless track mechanisms, lift means for said blade,` and means for operating said lift means from said source of power; the

ends of said blade being adjustable through saidthrust means simultaneously with said track mechanisms. f'

21.` An earth working machine adapted for use in bulldorzing, trail building and like work; comprising a traction unit including y a body,A and opposite endless track mechanisms movably connected thereto for relative endwise' adjustment; g

said mechanisms being adjustable to position similar ends thereof in longitudinally displaced relation with either of said similar ends in leading position or to position said ends in lateral alignment; and a blade unit including la, blade, and means connecting said blade adjacent the ends thereof to 'said endless track mechanisms; the ends of said blade being, adjustable through said connecting means simultaneously with said track mechanisms.

22. In an earth working machine; a body including a case; opposite endless track mechanisms including track frames; and means connecting said track mechanisms to said body; each connecting meansV including a final drive housing, a pivotal connection between said'housing and said case, a shaft mounted in said housing parallel to and displaced from the axis of said ypivotal connection, and a pivotal connection becluding a case having drive meanstherein; opl posite endless track mechanisms; each track mechanism including a track frame having a forked end forming extensions; means connecting said track mechanisms to said body; each connecting means including a final drive housing, a pivotal connection between said housing and said case,'a shaft mounted in said housing parallel to and displaced from the axis of said pivotal connection; and aligned pivotal connections between said shaft and said end extensions;

a drive sprocket journaled in said housing about the yaxis of said shaft; and a drive connection from said drive means extending through said housing to said drive sprocket.

24.'In an earth working machine, a body, opposite endless track mechanisms,'means 'connecting said track mechanisms for'relativeendwise adjustment, an earth-engaging tool, means connecting said tool to said track mechanisms for movement therewith, and means associated with said tool Aconnecting means for compensating for the effective change in width between the points of connection of said connecting means tov said tool upon said endwise adjustment of said track mechanisms. l v

25. In an earth working machine, a body, oppositeendless track mechanisms, means connecting said track mechanisms for relative endwise adjustment, an earth-engaging tool, and thrust being yieldable to compensate for the effective means connecting said tool to said track mechanisms for movement therewith, said thrust means change in width between the points of connections of said thrust means to said tool upon said end wise adjustment of said track mechanisms.

26. In an` earth working machine, a body, opposite endless track mechanisms, means connecting said track mechanisms for relative endwise adjustment, an earth-engaging tool, and thrust means connecting said tool to said. track mechanisms for movement therewith, said thrust means being movably connected to said tool to compensate for the effective change in width between the points of connections of said thrust means to said tool upon said endwise adjustment of said track mechanisms.

27. In an earth working machine, a body, op-

posite endless track mechanisms, means connect-' ing said track mechanisms for relative endwise r' thrust adjustment, an earth-engaging tool, means connecting said tool to said track mechanisms for movement therewith, and shock absorbing means associated with said thrust 'means 4and said tool allowing yielding movement of said tool.

28. In an earth Working machine, a body, opposite endless track mechanisms supporting said body and connected thereto for relative endwise adjustment, a bulldozing blade adjustably connected to said track mechanisms adjacent one Aend of said body, lift means for said blade including a linkage connected thereto adjacent each end thereof, lift links extending from said linkages along said body, a transverse member mounted for longitudinal movement on said body and connected to said lift links, a power shaft mounted in said body, and selectively operable means connectingv said power shaft and said member.

29. In an earth working machine, a body, opposite endless track mechanisms supporting said body and connected thereto for relative endwise adjustment, a bulldozing bladeextending transversely of said body, U-shaped thrust frames embracing the front ends of said track mechanisms and having their respective open ends plv-i otally connected thereto, the closed ends of said frames being connected to said blade, and adjusting means connected to said thrust frames.

' 30. In an earth working machine, a body, supporting means for said body including along nisms placing both sets of similar ends thereof in longitudinally oii'set relation,A and -bulldozing blade means atl each end of said machine, the oilsetting of said sets of ends serving to provide positioning of each of said blade means at an oblique angle with respect to the. longitudinal axis of said machine. A

31. In an earth working machine, a body, supporting means for said body including a long track mechanism and a shorter track mechanism, the diierent lengths of said track mechanisms placing both sets of similar ends thereof in longitudinally offset relation, bulldozing blade means at each end of said machine, the offsetting of `said sets o! ends 'serving to provide positioning of each of said blade means at an oblique angle with respect to the longitudinal axis of said ma- Y chine, and an operators stationon said body and facin-g said long track mechanism.

32. In lan earth working machine, a body, a

track mechanism at eachl Aside of said body,

. body,

` displaced, and an earth working track mechanism at each side of said body, means for connecting said track mechanisms to said body with similar ends thereof adapted for longitudinal displacement with respect to each other, means for effecting adjustment of said track mechanisms relative to each other to vary said displacement, power transmitting means including a transmission in said body for driving said track mechanisms, and means independent of said transmission for reversing said drive whereby the machine can be operated backwardly and forwardly with rapidity.

34. An earth `working machine comprising a. body, means for positioning an earth working tool at an oblique angle with respect to said body, and spaced ground supports connected to said body for propelling said body along the ground, said ground supports having connections to said tool and being longitudinally displaced adjacent said tool to stabilize said tool at spaced locations.

35. An earth working machine comprising a opposite ground-engaging means for propelling and supporting said body, similar ends of said ground-engaging means being longitudinally tool supported in stabilizing relationship by said ground-engaging-means adjacent said similar ends.

36. An earth Working machine comprising a body, ground supports for propelling said body and connected to said body for relative movementwith respect to each other to provide for positioning of similar ends of said supports in longitudinally displaced relationship or in lateral alinement, and an earth Working tool extending transverselyv of said body adjacent said similar ends of said supports and supported by said supports in stabilizing relationship with respect to said similar ends in any of the relatively adjusted positions of said supports.

37. An earth working machine comprising a body, opposite endless track mechanisms for supporting said body with similar ends thereof longitudinally displaced, and an earth working tool extending transversely of `said body adjacent said similar ends foi said endless track mechanisms and connected to said endless track mechanisms in stabilizing relationship with respect to both of said similar ends.

38. In an earth working machine, an earth working tool disposable at an oblique angle with f respect to the longitudinal axis of the machine,

spaced ground-engaging means for supporting and propelling saidA machine, means mounting said ground-engaging means for relative longitudinal adjustment with respect to each other,

and means to support said tool on said ground`4 engaging means to maintain a substantially constant relationship between the ends of said tool and said yground-engaging means irrespective of the angle of said vtool and the adjustment of said ground-engaging means.

39. In an earth Working machine, spaced endless track mechanisms `for supporting and propelling the machine, an earth working tool positioned adjacent similar ends of the track mechanisms andA disposed at an oblique angle with respect to the longitudinal axis of said machine, and means for supporting both end portions of I tially the tool on said track mechanisms in substanthe same stabilizing. relationship including an arrangement whereby the end of the track mechanism adjacent the leading end of the tool is in advance of the corresponding end of the other track mechanism.

40. In an earth working machine, spaced endless track mechanisms supporting said machine with similar ends longitudinally odset-with respect to each other.

the longitudinal axis of the machine and connected to said endless track mechanisms substanand an earth-engaging toolA extending at an oblique angle with respect totially the same distance from each of said similar ends.

41. A track-type bulldozer machine adapted to support a bulldozer tool in an oblique position adjacent an end thereof for bulldozing and the like work, comprising a tractor body, and spaced endless track mechanisms supporting said body. the ends of said track mechanisms adjacent said tool end of the ma.- chine being longitudinally offset to cooperate with said tool in providing stabilizing supporting means therefor in the oblique position thereof. OSCAR` L. STARR.

forV propelling and