US1745540A - Tractor snowplow - Google Patents

Description

2 Sheets-Sheet 1 Filed 001;. 3, 1927 m N b m AN o IP/I/V [$554 L INVENTOR.

ATTORNEY Feb. 4, 1930. ISBELL TRACTOR SNOWPLOW Filed Oct. 5.1927

2 Sheets-Sheet 2 i 9 A \N 1 \NE Y Patented Feb. 4, 1930 LORAN ISBELL, 01* LITTLE YORK, NEW YORK- TRACTOR SNOWPLOW Application'filed October 3, 1927. Serial R o. 223,760.

My invention relates to a heavy duty snow plow suited for attachment to a tractor, particularly one of the crawler "or track-tread type, and embraces certain novel structural 5 improvements together with control devices for clearing a relatively deep snow bank or heavy snow fall from roadways or the like.

Snow-bound highways or roads when blocked to motor vehicle traffic, can rapidly and economically be cleared by means of my heavy-duty snow plow device because it provides for three vital factors upon'which successful snow removal depends, namely; adequate mobility or plowing speed when clear inga deep bank of heavy snow, spacious width of road obtainable under such adverse conditions, and finally leaving "a sufliciently smooth road bed that will be usable for traific. The contemplated use of a separate and distinct conveyor engine means permits comparatively small motive power on part of the tractor to efiect this result and said conveyor furthermore serves to deliver loose snow on top of a wide unpacked side bank, all of which facilitates a further widening of a road cut or passage, should this be required. My snow plow also eliminates the need for imposing extreme ram reactions upon the pushing tractor such as frequently becomes necessary when using the conventional V nose type Of'PlOW, thus doing away with excessive repairs, breakdowns and consequent Waste of motive power.

In its preferred embodiment, my present plow may be driven by-means of a rugged hollow cradle-like structure adapted to receive the tractor therein and which cradle prilnarily comprises a pair of longitudinally disposed spaced side or push beams with my 40 snow removing element carried across the forward ends thereof while their rearward, ends are enclosed by a still? cross-beam or draft member whose medial portion is pivotally attached to the'draw-bar or other T tractor draft rigging located back of the drive wheel tread. The propulsive eifort required to push ahead said plow element is aiforded a by the draw-bar pull of the tractor and this load is'preferably transmitted forwardly through said complementary thrust beams extending around the tractor sides. The snow cutting element utilized in this connec tion is preferably of the substantially straight blade type as disposed across the path of plow travel.

An importantobject is therefore to provide necessary means for properly operating with a wide blunt blade of this kind in order to be able'to plow through snow-bound road-beds and open the same for traffic, also to otherwise meet the exacting performance now expected of a snow plow intended for such highway purposes. To thisv end my transversely disposed plow blade is preferably carried by a separate unitary framework equipped with a scoop plate mounted to the rear of the blade in an upwardly inclined relation across said side thrust beams, and this sloping plate may be made to 00-- operate with an upright mould board adapted to divert the plowed snow toward one side of my plow frame. This sidewise movement of the plowed snow may be expedited along said guide elements by suitable ejector or auxiliary conveyor means driven by a separate engine or other motive-power carried upon the plow frame and kept entirely independent of the tractor prime mover.

Certain of the structural details underlying my present plow frame are not unlike those set forth in my snow plow Patent No. 1,629,341 granted May 17, 1927, except that in the present instance, the plow frame is no longer pivoted upon a vertical post carried at the front of a propelling truck but instead may now be mounted upon said hingeless onepiece push beams and this cradle-like structure is pivoted upon transversely disposed pintle means rigidly carried by the tractor draw-bar.

A further object resides in providing for an improved rear support mounting allowing said cradle structure to be bodily tilted about its rear pintle for the purpose of raising or lowering the forward blade end thereof; this is accomplished by suitable horizon tally disposed runner means equipped with interposed control means adapted to conveniently adjust the cutting height of said blade one of the push beams and serves to counter act any lateral drift tending to bodily swerve the tractor drive sidewise in case one of said spaced push beams .should 7 become more heavily loaded than its mate. Such stabilizer device has been found particularly beneficialwhen only one end portion of my transversely disposed blade is utilized in plowing alongside a deep cut for the purpose of widening .out a partially excavated bank of drifted snow or-the like. Under conditions of such uneven blade loading, my improved plow is designed to have the utilized blade end head toward the adjacent newly formed snow bank rather than crowd away therefrom, and in order to compensate for the resulting blade drift, lprovide for a compensating trailing shoe means adapted to thrust laterally against .he upright cut or bank precipice that is left by the effective end portion of said blade.

In addition, I contemplate equipping my plow with improved brace means as embodied in a pliable tie chain which is transversely disposedacross a medial portion of said side beams and interconnects to a lower forward part of the tractor such as its front axle. The blade end of my cradle preferably extends some distance ahead of the tractor and in order to further facilitate the steering of such forward projecting cradle portion, I provide for novel resilient auxiliary supporting means adapted to take up a substantial part of the forwardly overhung weight and throw this upon the front wheel tread where it aids in more evenly distributing the reacting plow load over the tread track and in augmenting tractive effort withrespect to the plowed roadbed. Said supporting means also serves to relieve the load that would otherwise have' to be carried by my adjustably runner shoes and in turn eases the indicated tilting manipulation on part of the cradle structure about its horizontal rear pintle.

Embodied herein are also certain other features of structure and organization, all of which will be set forth in detail hereinafter. Reference is had to the accompanying two sheets of drawings as being illustrative.

while 2 shows an elevational side view thereof.-

Fig. 3 represents a rear end viewand Fig. 4

w an elevational sectional view taken along line H f Fig. 2.

Fig. 5 shows a detail of a suitable shoe adjusting means adapted to raise or lower the blade end of my pivoted plow cradle structure.

The reference character A indicates in its entirety a suitable tractor of the conventional Caterpillar or track-tried type Which is provided with the usual rear axle housing A and with a front axle A Thelatter members are generally spaced apart longitudinally to carry therebetween the tractor body indicated as a whole by A and this body among other ordinary components, comprises an engine compartment A and an engine radiator A all of which common elements will readily be understood without a more explicit showing.

Within the tubular housing A there may be mounted the customary sectional rear axle A whose outermost ends project beyond this housing and respectively carry a rear drive or ground wheel such as A The motivepower may be applied to said pair of spaced wheels in any suitable manner but the rear axle sections are preferably driven by the tractor engine A through a train of speed contolled differential gears such as A capable of compensating in the usual fashion for differences in speed of rotation of the two rear wheels when it is desired to steer the tractor and. have it make a turn.

The front axle ends may respectively be provided with front wheels such as A and for present purposes these may be of the plain or rigid spindle type operating without steering knuckle joints; that is to say, the axles A and A, together with their respective wheel pairs may be kept in fixed alignment,

although this is not an essential requirement. For steering my snow plow through tractor power, sprocket type ground wheels may be resorted to and their respective front and rear rims interconnected by separate chain tread or belt means A and A in the well known Caterpillar tractor fashion as indicated by the drawings. In order to further briefly identify the tractor characteristics preferred, a brake band A or other independent wheel drag means may be applied to each of the treads A and A' for convenience of illustration this has here been located Within the front wheels as is schematically shown in dotted outline. It is however customary to apply such drag means to each of the rear Wheels rather than to the front wheels; it will be further understood that the use of said interconnecting tread chains are non-essential since by vthus transposing the brake bands, such chains can be omitted without materially affecting the proper operation of my plow devices.

The actuation of the brakes A or other equivalent drag means may be placed under control of the steering wheel A when operatively connected in the conventional manner, either one of said brake bands may be separately applied to exert a varying degree; of drag upon the. corresponding drive wheel and this in turn causes a slowing up thereof while the complementary drive wheel will be sped up by virtue of the differential gear acw cite-d because they may be utilized in combination with certain features thereof.

Securely attached to a rear portion of the tractor body A; and centrally disposed between the wheel'treads, there is shown a drawbar cap A which comprises a rearwardly ex- I tending hitch tongue member A preferably site sides of the tractor A disposed somewhat below the rear axle level and provided with one or more bolts A to facilitate the attachment of my hitch rigging.

Referring now in detail to the more essential structural features embodied into my tiltable plow cradle B this primarily consists of a pair of jointless push or side beams B and B- which may be parallelly disposed in spaced relation to freely clear the oppo- These compara: tively long but rigid thrust members are intended to carry the plow load without undue flexure and to this end such beams are preferably given a channel profile shape with their respective flanges turned inwardly to face the tractor sides as shown. The rearmost ends of said side beams B and B may be interconnected by a cross-beam or transverse draft member B and this may also be given a rigid channel profile shape with its top and bottom flanges extending rearwardly as shown in Fig. 2. For the purpose of forming a detachable joint between the aforesaid beam members, each rear end of said side beams are preferably provided withcomplementary top and bottom tie straps B and B 4 respectively riveted to thepush beam flanges in spaced overhanging relation such that they may snugly embrace the corresponding flanges of the cross-beam B therebetween; each such joint may be secured by a removable coupling pin B which extends'through aligned apertures in the mannerindicated.

It is pointed out that this breakable type of transverse beam connection facilitates runing the tractor into or out of the cradle structure in case it is desired to use the tractor for other purposes. As will appear presently,

the spaced forward ends of the side beams tended to afiord suflicient room to freely receive the tractor.

Secured to the cap torque A by the bolts A or otherwise, is a draw-bar attachment or rigging designated as B and this comprises a pair of spaced rearwardly extending bearings ears such as B; between which is mounted a transversely disposed fulcrum or pintle shaft B Rigidly secured to the forward ,web face of the cross-beam B is a bracket having a pair of perforated rnturned arms such as B that center upon said shaft and form a knuckle joint with respect to said ears. The purpose of said pivoted joint is to hingedly support the rearward end of the cradle structure B and allow the forward cradle end to be tilted vertically upward about said'pintle into the position shown by dotted lines in Fig. 2. In order to afford additional brace means in support of the transverse pintle B there are also provided complementary spaced struts such. as B of which the respective rear ends engage said shaft B of the bar attachment B while the respective forward strut ends may. each be provided with split caps adapted to surround the axle housing A and brace thereagainst adjacent to the respective rear wheel hubs as indicated.

Taking up now the structural details pertaining to my separate plow frame which is propelled ahead of the tractor, this frame is disposed upon the front portion of my cradle B and across the side beams B arid B' thereof; the extreme forward portion of said plow frame may be provided with a relatively flat blade C whose cutting edge C' preferably extends straight across said side beams in rec ilinear relation as shown in Fig. 1, although a dentate blade edge or a V nose plow blade may be substituted for said plain straight type.

The forward end of each side beam such as B may be cut off on the bias B so as to constitute a tapered web section extending down to the respective lowermost beam flanges in the manner indicated by Fig. 2. Superimposed upon said bias and firmly secured to the respective ends of the blade C are a pair of longitudinally disposed plow frame members or bars C2 and 0 2 which extend rearwardly in and upwardlyinclined relation and stradde the respectiveouter sides of said thrust beams. The frame side bars C and C may be interconnected by various cross or obliquely disposed reenforcing members. such as the transverse bar C the strut bars Cqthe complementary diverging bars C or v the like which go to make up a self-containedplatform-like framework adapted to lie across the forward end of said push beams B and B' This separate framework may be bodily.

secured to the beam webs by bolts, rivets or the like fastening means such as G, and this frame ma be additionally secured through be partially or wholly covered by an inclined scoop plate C disposed immediately behind the blade C and extending rearwardly therefrom so as to raise the plowed snow somewhat with respect to the plow blade cutting level. The aforesaid separate framework is substantially identical in structure with that contained in my patent previously identified and it will be seen therefore that by virtue of my improved mounting, I am enabled to interchangeably hitch up the same frame work either to the front of a truck as: disclosed in my prior patent or to a tractpr in the manner described herein.

In either case it is preferred to, employ a snow ejector device capable of conveying the snow from the plow frame. Said ejector may be of the endless belt or chair? type comprising a set of obliquely disposed link loops such as C that may run rather close to one end of the plow blade C and thence slant rearward across the inclined frame platform as indicated. These complementary chain belts may be mounted upon suitable end sprocket shafts and provided with sweeping cleats C' therebetween adapted to pick up the plowed snow oif the scoop plate C In order to facilitate this mode of operation, a length of said chain belt is preferably mounted to run .beneath the level of said plate while an upper belt length may be made to ride over the top'face of said plate. One of the said end sprocket shafts may be driven by a supplementary endless chain G which in turn is actuated by a separate auxiliary internal combustion engine orother motor C preferably carried upon my frame platform and operated entirely independent of the tractor engine A As will be; apparent, all of said auxiliary power equipment together with the described conveyor means may be bodily raised or lowered by tilting the forward end of the cradle structure B about its rear fulcrum shaft.

.Mounted closely adjacenTto the rearward side of the obliquely disposed conveyor belt C and extending substantially upright out of the inclined scoop plate C is a mould board C, here shaped to direct the plowed snow toward and over one side of my frame work; the movement of snow along this board is expedited by the aforesaid conveyor which is. given ample capacity to remove and 11ft the snow away as fast as it is being plowed; this in turn, prevents the snow from ,being tightly packed against the obliquely disposed upright mould board and obviates setting up a heavy lateral pressure suflicie'nt to throw the plow blade outwardly and away from the newly cut snow bank. Said conveyor at the same time serves to further el vate and deliver the snow on'top of a bOIdt ing snow bank or loading truck ratherth'an have to virtually squeeze the plowed snow into any deep adjacent snow bank in the manner that obtains when working with the ordinary V nose type of plow.

For the purpose of effectually tilting my cradle structure, a pair of adjustable shoes or other suitable runner means C are pro-.

main on the roadbed. This may be accomplished by using pairs of interposed toggle links C and 0' for each shoe as shown in Fig. 5, and which links are here intended to be adjustably drawn together by a selflocking screw rod C in themanner indicated. The rear ends of eachsuch screw rod may be equipped with a universal joint which respectively engages separate extensible adjusting shafts such as C these two shafts may in turn be interconnected for simultaneous rotation by the cross-shaft C which is adjustably set by the centralized worm gears C which may be controlled by a suitably placed hand wheel or the like (not shown). It will be obvious that a proper turning of said hand wheel will cause the cradle structure B to be tilted in the fashion represented in Fig. 2 by dotted lines.

In order to impart ample lateral rigidity to the forward extending or frame carrying portion of said cradle when this is swerved sidewise while running the' respective wheel treads at unequal speeds, there are provided the complementary guide chains D and D that are tied between the push beams in a substantially horizontal relation as shown in Fig. 1. Such pliant tie means may be adjustably connected to the front axle A by means of spaced clips D and D g clamped or riveted to said axle adjacent to the respective wheel hubs in the manner indicated by Fig. 4. The lower depending end of each such clip may be apertured to receive a grab link D of key-hole like contour into which the respective inner chain ends are adapted to in terlock in the usual take-up fashion. It is preferred to cross said chains and carry their respective outward ends into secure engagement with a medial portion of the thrust beams B or B To this end, said beam webs may be drilled to receive an eye bolt such as D. having a comparatiyely long threaded shank and adjusting nut adapted to draw the spaced side beams into any desired alignment through the medium of said guide chains andthus maintain said beams in ample spaced relation with respect to the tractor sides. The lateral disposition of my flexible tie means is such that the side beams of my cradle are still. allowed to tilt vertically to a reasonable extent but these beams are at the same time prevented from contacting or otherwise binding against the movable tractor treads or wheel parts.

The major portion of my cradle weight normally'lies forward of the transverse pintle B} and except for my further improvements all of this would largely have to be carried by the spaced forward runner shoes C These shoes are also subject to a rather heavy downward thrust resulting from the cutting load imposed upon my inclined blade. For the purpose of transferring a substantial portion of the cradle load back to the ground wheel treads, it is preferred to resort to supplementary'supporting means such for instance as is incorporated in relatively powerful coiled springs D two such are used in the present embodiment and these may be symmetrically disposed with respect to the radiator front A in the oblique manner shown in Fig. 4. Each upper side of the radiator may be equipped with projecting lugs A having a hole therethrough adapted to receive one of the hookends of such a supplementary spring while its other hook end may be engaged by a conventional turnbuckle means D that reaches downwardly and is suitably linked to a saddle piece D said piece'being here adapted to grip the lower flange of a push beam intermediate its ends. The stipulated disposition allows said springs to cooperate with the complementary tie means D and D in assisting to hold the cradle in proper alignment against side swerving while being steered through the tractor and at the same time serving to increase the tractive efi'ort or road grip on part ofthe tread chains A and A because of the augmented weight which said auxiliary springs transfer thereto. It will be also be obvious that said supplemental lifting means are capable of relieving to a considerable extent, the overhung cradle load which my runner shoe 0 would otherwise be obliged to carry and all of which advantage expedites the vertical manipulation of my shoe toggle devices and likewise facilitates the sidewise steering of my plow blade.

As a further refinement, attention is directed to the use of my thrust or stabilizer shoesuch as E of which the forward end may be pivotally carried upon a pintle bracket E this being preferably secured alongside the web of a push beam such as B and disposed in close proximity to theblade end thereof.

The free ehdof said pivoted shoe may be positively swung toward or away from said web by means of a toggle linkage E in a manner not unlike that previouslysdes cribed in connection with my runner shoes. The desired setting given to the shoe toggle may be controlled from the rear of my cradle by means of a distant control gear here comprising the linked up pull rod- E the rocker E and the push rod E the last named rod being disposed inwardly of the beam web as shown with its rear end placed under control of the manipulating lever E which in turn may adjustably set through the medium of the notched sector E It will be apparent that when this lever handle is moved into its extreme forward position as shown, then the free end of the shoe E will be drawn inwardly closely adjacent to the beam B' while when the lever is moved rearward, the toggle E will push said shoe outwardly into its extreme outer position shown in Fig. 1 by dotted outline.

I The described stabilizer expedient has been found particularly serviceable when it is desired to enlarge a deeply beaten snow path or to further remove snow from one side of a partially excavated cut running through a heavy snow drift or the like. In the event that an abnormally deep cut has to be taken, it is expedient'in order not to overload the tractor engine, to plow through a high snow bank of this kind in piecemeal fashion and to utilizeonly a limited portion of my transverse plow bladelength, preferably that end portion that is equipped with the equalizer shoe E. As a consequence of such eccentric blade loading, the respective push beams are subjected to an unequally distributed thrust, which in turn sets up a resultant turning moment with respect to the draw-bar pull that tends to bodily swerve the tractor, thus causes the operative end portion of my plow blade to head toward and into the side of the adjacent snow bank that is being plowed out. The use of my intermediary thrust shoe corrects the persistent digging in of the operative blade end. Said shoe is made to trail closely behind the blade end and to glide along the upright snow bank side-face or precipice immediately upon its being cut by the plow, and the stabilizer device is preferably placed rather low and near to the roadbed where it is most likely to ride along the more closely packed hard snow. My conveyor is so disposed that it cooperates to elevate and discharge the plowed snow on top .of the bordering bank against which my equalizer shoeglides, thus leaving the opposite plow side entirely free to pass through highway trafic therearound.

It is pointed out that when working with the substantially straight plow blade C the cited heading-in of my blade edge acts in a reverse direction from that experienced when using a nose plow-blade under similar conditions, this latter type tends to throw and head the plow bodily away from any deep snow bank into which it may be partially directed. This inverse action of my straight plow blade is in part associated with the use of the described conveyor which in large measure. relieves the mould board of lateral Said stabilizer shoe provides a simple and effective method for introducing a counteracting lateral thrust and that serves to rectify the cited erratic tractor drive action; a relatively light tractor has proven deficient in steering power as applied to present plow drive purposes and unless provided with such stabilizer, has been found impossible to prevent the operative plow blade end from being unduly drawn into the adjacent snow bank. A comparatively small shoe surface and a limited toggle adjustment usually suffices to bring about the desired results and since the angular setting of my shoe may be conveniently controlled by said rear lever E the compensating side thrust borne thereby may be altered from time to time for the purpose of maintaining proper equilibrium and correcting any ordinary swervin tendency on part of the tractor drive. aid novel shoe device keeps the plow traveling in a substantially. straight course and prevents undue lateral blade drift from overtaxing the tractor steering devices or the tractor engine, and hence the necessity for frequent gear shift is obviated.

As a further advantage afforded, said stabilizer means eliminates the need for partially-applying any substantial steering brake drag to either of the drive-wheel treads while lowing with but one end portion of the blade; hence the resulting conservation of power augments the effective draw-bar pull obtainable under maximum blade load. My

plow devices are especially suited for plowmg into deep snow beds such as are likely to be met with in clearing state highways in cold, climates; when used for removing light snowfalls, there is no need for employing my stabilizer.v In fact it is em hasizedthat said shoe member is not intende to function in the fashion ofsupplemental side wing means servin to-substantially widen out the path of a primary plow blade; instead my shoe always remains rather closely held to its adjacent push beam in order to set up the desired effective lateral thrust and only incidentally serves to augment-the sweep width of my plow blade.

The intended cooperation between the various described plow features and its tractor should be readily perceived from the preceding explanations. An important aim is to provide the cited cradle means for attaching my plow frame to any of the more common types of tractors as equipped with suitable steering devices and having a rear draw-bar adapted to expedite the hitching up or unhitching of my cradle structure thereto. It will be observed that the" hitch rigging de L scribed can readily be fitted to existing tractors particularly to a modified or full crawler Fordson tractor type such as the drawings are intended to illustrate.

Assuming that such a tractor has been equipped with my auxiliary cradle rigging, then in order to allow of unhitching the tractor, it is merely necessary to remove the two coupling pins B to release the guide chain's D and D also to unfasten the complementary lifting means D whereupon the tractor may be -freely backed out of the rear of the open cradle B Certain of the described accessory cradle parts may be carried along Withuthe tractor but when it is desired to utilize the tractor for other purposes, any such interfering parts may be. removed until such time that my snow plow is again to .be reassembled.

As regards the steeringof my plow cradle, this as.stated is preferably accomplished by applying the brake drag A to one of the wheel treads, thus causing the tractor and its plow frame to turn about a vertical axis located approximately midway of such complementary tread lengths. This in turn throws the forward blade end of my cradle structure around sidewise and swings the runner shoes therewith. In order to bodily swin the heavy projecting forward end of my p low cradle in this manner, requires considerable steering force and it is partly for this reason that I prefer to resort to the Caterpillar mode of tractor drive; this type at the same time affords the maximum of tractive effortand my ruggedly built heavyduty cradle structure is adapted to apply such load to the front plow blade without detrimental efiects. This result is primarily brought about through the use of spaced push beams B and B as fashioned into long continuous and substantially rigid drive members without need for intermediate hinged joints of any kind; said beams are capable of transmitting a heavy straight-line thrust from the rear tractor draw-bar directly to the opposite ends of my rectilinear plow blade, thus leaving a smooth even road without suffering any washboard effect whether the runner shoes are adjusted for deep or shallow plowing of snow;

The structural plow features illustrated and described herein'have been found by extended tests to function eificiently and to fully v snow plowing element extending across and propelled in front of said tractor, a pair of substantially rigid push beams respectively adjoined to opposite end portions of said element and extending longitudinally rearward around the respective tractor sides, a transverse draft member spanning the rear beam portions and forming therewith a cradlelike structure adapted to rbceive the tractor, a draw-bar rigging carried near the rear of said tractorprovided with a horizontal pintle means serving to mount the rearward end of said structure, runner means adapted to support the forward position of said pivoted structure, lateral brace means, attached intermediate the respective ends of each push beam and extending horizontally inward and tied to a forward portion of said tractor, and resilient auxiliary spring support adapted to cooperate with said lateral brace, said support being also attached intermediate the re spective beam ends and extending upwardly therefrom for connection to a forward tractor portion lying above the aforesaid brace tie.

2. In a power driven tractor means, of a snow plow frame extending across and propelled in front of said tractor, said frame comprising a transversely disposed plow blade with a scoop plate member mounted rearwardly thereof, a pair of push beams re spectively adjoined to opposite sides of said frame and, extending longitudinally rearward around the. respective tractor sides, a transverse draft member bridging the rear end portions of said push beams and form ing a hollow cradle-like structure therewith adapted to receive the tractor, a drawbar rigging carried near'the rear of said body and provided with horizontal pintle means for tilting said structure thereon, adjustable runner means adapted to support the forward portion of said pivoted structure auxiliary support means of the resilient type interconnecting the forwardend portion of said body with an intermediate portion of the spaced push beams, and manually operable adjusting means forraising or lowering the structure with respect to said runner means.

3. In a tractor means provided with a longitudinally disposed body portion, a snow plow element extending across and propelled in front of said body, a pair of push beams respectively adjoined to opposite end portions of said-element and extending longitudinally around the respective tractor sides,

- a transverse draft member bridging the rear portiQns of. said beams to form a'cradle-like structure adapted to receive the tractor therein, a draw-bar rigging disposed toward the rear of said body and provided with pintle means for vertically tilting said structure thereon, runners serving to carry the forward end of said pivoted structure, and supplementary spring support means disposed between a forward portion of said body and both push beams intermediate the respective end portions of said beams.

4. In a tractor means provided with a longitudinally disposed body portion, a snow plow element extending across and propelled in front of said body, a pair of push beams respectively adjoined to opposite end portions of said element and extending longitudinally around the respective tractor sides, a transverse draft member bridging the rear Y portions of said beams to form a cradle-like structure adapted to receive the tractor therein, a drawsbar rigging disposed toward the rear of said body and provided with pintle means for vertically tilting said structure thereon, runners serving to carry the respective forward end portions of said beams, supplementary spring support means attached intermediate the respective beam ends and adapted to relieve the runners from carrying the full burden of overhung structure load, and steering means associated with the tractor for swerving said runners sidewise.

5. In a tractor means provided with a longitudinally disposed body portion, a snow plow element extending across and propelled in front of said body, a pair of push beams respectively adjoined to opposite end portions of said element and extending longitudinally around the res ective tractor sides, a transverse draft member bridging the rear portions of said beams to form a cradle-like structure adapted to receive the tractor therein, a draw-barrigging disposed toward the rear of said body and provided with pintle means for vertically tilting said structure thereon, runner means bearing upon the roadbed and adapted to support the forward end of said structure, manipulative lifting means including a toggle-like mechanism interposed between said runner means and the structure adapted to adjustably raise the latter about said pintle means, and supplemenverse draft member bridging the rear portions of said beams to form a cradle-like structure adapted to receive the tractor therein, a draw-bar rigging attached to the rear of said body and provided with pintle means for vertically tilting said structure thereon, runner means bearing upon the roadbed and adapted to support the forward end of said structure, stabilizer shoe means carried by one of said beams in a trailing relation to the blade end thereof, and control means interposed between said runner means and the structure adapted to adjustably raise or lower the cutting height of said blade and simultaneously tarry said shoe therewith.

7. In a tractor means provided with a longitudinally disposed body portion, a snow plow of the platform type comprising a transverse blade propelled in front of said tractor, a pair of push beams of the straight-line type respectively adjoined to carry opposite sides of said platform and extending longitudinally rearward around the respective tractor sides, a transverse draft member bridging the rear portions of said beams to form a cradle like structure adapted to receive the tractor therein, a draw-bar rigging attached to the rear of said body and provided with pintle means for vertically tilting said structure thereon, runner means bearing upon the roadbed supporting the forward end of said struc ture, supplemental lifting means adapted to partially relieve said runner from carrying its full burden of overhung structure load, stabilizer means associated with the blade end of one of said beams, and power driven conveyor means adapted to elevate the plowed snow with respect to the blade level, said means being adapted to discharge the plowed snow over the beam equipped with said stabilizer. I

8. In a tractor means provided with a longitudinally disposed body portion, a snow plow element extending across and propelled in front of said tractor, a pair of'substantially rigid push beams respectively adjoined to opposite end portions of said element and extending longitudinally rearward around the respective tractor sides, a detachably connected draft member bridging the rear beam portions to form a cradle-like structure adapted to receive the tractor therein, a draw-bar rigging carried at the rear of said tractor provided with pintle means for vertically tilting said structure" thereon, runner means adapted to carry the forward end of said structure, detachable auxiliary support means acting between said body and said beams, and lateral brace means detachably tied to the respective push beams and to the forward portion of said body, said draft, lifting and brace members when detached, permitting the tractor to be freely run out of open rear end of v said cradle structure.

'9. In a snow plow provided with a plow element adapted to be. pushed by power driven propelling means, athrust means adjoined to said element and extending rearward for attachment to said propelling means, steering element serving to stabilize the steering devices, the last named means being adapted to thrust against the snow bank newly cut by the aforesaid one end of the plow element, and power driven conveyor means adapted to elevate the plowed snow for discharge over the aforesaid snow bank.

10. In a snow plow provided with a plow element adapted to be pushed by power driven propelling means, stabilizing means serving to compensate for unbalanced distribution of plowing load along said element and to overcome the resulting sidewise swerving tendency on part of said propelling means, said stabilizing means being adapted to thrust against the remaining snow bank precipice formed at one end of the plow element. and power driven conveyonmeans adapted to elevate the plowed snow for discharge over lizer means movably carried by said thrust I means and adapted to cooperate with the adjacent snow bank left behind said plow element, and adjusting means for changing the degree of stabilizationeflected ,by the aforesaid means, said means serving to shift the stabilizer means relative to the thrust means.

12. n a snow plow provided with a transversel disposed plow element adapted to be pushed by power driven propelling means, a pair of thrust members respectively adjoined to the end portions of said element for operative attachment to said propelling means, and stabilizer shoe means of which one end is pivotally disposed upon one of said thrust members and adapted to cooperate with the ad jacent snow bank left behind said plow element, and self-locking means for adjustably setting theother end of said shoe "with respect to said one thrust member.

13. In a snow plow provided with a transversely disposed plow element adapted to be pushed ahead of power driven propelling means, a pair of thrust members respectively adjoined to the end portions of said element and extending rearward for operative attachment to said propelling means, and stabilizer shoe means 0 which one end is pivotally disposed upon one of said thrust members, selflocking means for adj ustably setting the other gitudinally disposed body portion, a snow plow element propelled in front of said body, a' pair of push beams respectively adjoined to the opposite end portions of said element and extending longitudinally rearward around the respective tractor sides, a transverse draft member bridging the rear portion of said beams and operatively connected to the rear portion of said body, stabilizer means carried at the forward end portion of one such beams, and means for changing the degree of stabilization effected by the afore said means, said changing means comprising a distantcontrol' gear operatively adjustable from a rearward portion of said tractor.

In testimony whereof, I have herewith set my hand this 28 day of September, 1927.

. LORAN ISBELL.

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