US1524518A - Snowplow - Google Patents

Description

Jan. 27, 1925. 1,524,518

J. C) JCJFHQSCDN SNOWPLOW Filed Aug, 23, 1923 2 Sheets-Sheet 1 Jv/m Ta/mama J. O. JOHNSON SNOWPLOW Filed Aug. 23, 1923 2 Sheets-Sheet 2 gwuentoz Jb/n 0. J /mm/n Patented Jan. 27, -1925.

UNITED STATES JOHN O. JOHNSON, F WHITE BEAR LAKE, MINNESOTA.

SNOWPLOW.

Application filed August 23, 1923. Serial No. 658,934.

To all whom it may concern.-

Be it known that I, JOHN O. JOHNSON, :1 citizen of the United States, residing at White Bear Lake, in the county of Ramsey 5 and State of Minnesota, have invented certain new and useful Improvements in Snowplows, of which the following is a specification. My invention relates to snow plows, 0 adapted to be attached to tractors, an obect of the invention being the provision of improved snow handling and plowing means, adapted to be driven by the motor of the tractor, and including snow expel- .5 ling devices, whereby thesnow may be arbitrarily plowed up and thrown either to the right or left of the road, orboth, as desired, improved novel controllin means being provided whereby the snow t rowing :0 mechanism on either side of the center line of the tractor may be arbitrarily rendered inoperative.

A further object of the invention is the provision of a power driven snow plow, :5 embodying plow mounting and controlling devices of novel construction, whereby the plow is enabled toyield vertically when driving over uneven ground, and whereby a large part of the stresses or forces de- 1 veloped by impact of the plow with the snow and ice, are transmitted directly to rhe rear portion of the tractor to utilize the weight of said tractor portion as "ballast, to avoid the tendency of lifting the front of the tractor when the nose of the plow digs into a bank of snow or under a led e of ice.

ther objects and advantages of my invention will be pointed out asthis speci m fication progresses, the invention consist; ing in the construction, combination, and

arrangement of parts hereinafter described.

- and claimed. y

In the accompanying drawings, forming part of this specification:

Figure 1, is a side elevation. of a snow plow embodying my invention, shown in. section on line 11 of Figure 2.

Figure 2, is a view of the top of same. Figure 3, is a fragmentary side view of one of the fan wheels.

Figure 4, is a vertical longitudinal section on line 4-4 of Figure 2.

.ures 1 and 2.

Figure 5, is a fragmentary perspective vlew of a part of the controlling mechanism for controlling the snow expelling devices.

Figure 6, is a fragmentary perspective view ofa part of the low mounting mechanism, whereby part of the forces developed in a plowing action are applied to the rear of the snow ploW.

dicating several positions assumed by the plow controlling parts.

Figure 11, is a side view of a detail; and Figure 12, is a perspective View of the plow unit, parts thereof being omitted.

In the drawings, I have shown my invention attached to a track laying tractor'of the internal combustion type, and more specifically to a tractor known as the Cletrack or Cleveland tract-or, it being understood, however, that my invention may be applied to any suitable type of tractor, whether of the track laying or ordinary g" traction type, by slightly modifying the means of connection therewith, without departing from the spirit of the invention.

The tractor shown comprises a truck portion, or, in other words, a wheeled portion including the traction mechanism, and a main frame, pivotally mounted upon said wheeled portion, can'yingfthe power plant or motor. i

This tractor embodies a peculiar construction, whereby the main frame, designated generally by the numeral 2, is pivotally mounted upon the rear axle 3 '(which is made of two sections), and spaced an appreciable distance above the latter, in a manner to swing in a vertical longitudinal plane with respect to the center line of the tractor.

The wheeled portion comprises a pair of similar side frames 4, at the rear portion 105 of which are carried, respectively, the rear traction wheels 5, by means of the shaft 4 sections 3, which latter are firmly held by boxes 3. Journaled, res ctively, in the forward portion of said of the journals 4', are the forward traction wheels 6, thetr-action wheels of each frame being operatively engaged by an endles flexible traction belt 7, here shown diagrammatically, the links thereof not being 1ndicated.

The manner of driving the tractor may be briefly described as follows: The rear traction wheels 5 are each formed with an internal gear 8 which meshes, respectively, with one of the pinions 9, carried by the differential shaft 10, said shaft extendin through the differential housing 11 beyon opposite ends thereof.' The h0us1 cured to the main frame 2,, as diagrammatically shown in Figure 9, and constructively shown in Figure 2, and is pivotally supported by means of bearings 13, respectively, on the shafts 3, to enable the main fijame to be swung in a vertical longitudmal plane with respect to the center line of the tractor. At its front end, the frame is supported on the side frames 4 by means of a semi-elliptic spring 14, to lend resiliency to the structure. This spring has suitable connections (not shown) at 16, respectively, with the side frames 4. Thus, the front end of the main frame is enabled to vibrate vertically about the shafts 3, as

indicated by the dotted lines in Figure 9, stabilizing irons 15 being provided to serve as guides to maintain the frame relatively positioned with respect to the wheeled portion of the tractor.

In the tractor shown, the rear drivers rotate on the.axles 3, the latter being firmly held, as stated'in the foregoing, in the traction frame constituted by the side frames 4 and-the spring 14. In Figure 2, 17 designates the motor, 18 the drive shaft, 18 the steering wheel, and 18" the seat.

To stabilize the frame against lateral displacement, guide members 15 are provided, there being one on each side of the frame. These guide members slide vertically in the sockets 15, secured one to the inner edge of each of the frames 4.

Extending downward from the under side of the housing, are the brackets 13 and 19, there being two on either side of the center line of the tractor, as shown by dotted lines in Figure 2 of the drawin s. These brackets support, respectively, t e axles 3, which latter are in longitudinal alinement endwise. Thus, an available portion of shaft is had, on either side of the center of the tractor between the brackets 13 and 19, as at 20 (Figure 2), to be utilized ames by, means is se-.

by means of bolts 20 upon the 'inner side of each of the side rails 2' of the main frame, a forwardly extending supporting bar 21, said bars having pivotal connection, respectively, by means of horizontally disposed pivot bolts 22, with a pair of links 23. The links are parallel and extend forwardly and downwardly to the inner sides, respectively, of a pair of mold boards 24 and are joined together at the center of the tractor to form a central rearwardly inclining ridge 24, the mold boards constituting a major portion of a plow unit, generally designated by the number 25.

Secured, respectively, at suitable points to the inner sides of the mold boards, one for each of the links 23, arebrackets 26, each bracket formed with a bifurcation extending parallel with the center line of the tractor and carrying a transversely disposed, horizontal pivot pin 27, extending through said bifurcation and through an opening 28 in the outer end of each of the links 23, which latter extend loosely into the bifurcation of the brackets, whereby the plow unit is pivotally connected to the main frame of the tractor, to swing in a vertical longitudinal plane thereon.

The plow unit 25 carries a pair of laterally alined horizontally disposed pivot bolts 29, arranged parallel with the pivot bolts 22 and approximatel in vertical alinement therewith. Pivotal y supported, one on each of the pivot bolts 29 and extending rearwardly and upwardly and, respectively, to and beyond the axles 3, are the strut or brace bars 30. The rear end of each of these bars is formed with a flat, upper plate 31, which slidably engages, respectively, the tops of the axles 3. approximately at the point 20 (Figure 2), so that the strut bars may be slid longitudinally thereon.

Slidably secured, one to each of the brace bars 30, as by means of bolts 32 to slide longitudinally thereon, is an adjustment plate 33, the end 33 thereof extending at ri ht angles to the plate 31 and bein adapte to engage with the axles 3. The late is formed with slotted bolt holes 34, wlereby, when said bolts are slackened, the plate may be adjusted longitudinally of the brace member to change the relative sition of he end or shoulder 33. By t is adjustment means, the distance between the pivots 29 and the shoulder is rendered variable for a purpose to be hereinafter explained.

adapted to loosely receive a threaded nut 36, in which is threaded the shank 37 of an upwardly extending adjustment crank screw, generally designated by the numeral 38. v

The adjustment screws pass respectively through openings 39 in the top and bottom walls of the socket 35 and loosely through openings 39 in the links 23. The screws are further formed with vertically spaced shoulders 41, betweenwhich, respectively, the horizontal webs of the links 23 loosely fit. The screws are each further formed with a crank handle 40. By the actuation of the screws, the pivots 29 may be raised or lowered to the desired level with respect to the ground. Extending transverselyof the tractor, through openings 42 of the mold boards 24, is the shaft housing 43, having flanges 44, one adjacent each end thereof, said flanges fitting snugly respectively against the mold boards, and being firmly bolted thereto.

Journaled in the housing, by means of the bearings 43, are the shafts 45, each carrying rigidly at its outer end a fan wheel 46, having a hub formed with a peripheral groove 46'. Midway between its ends, the housing is enlarged to form a gear chamber 47 having oppositely disposed journal bearings 47, which bearings axially aline with the shafts 45, and rotatably support respectively the ends of the hub 47 of a bevel gear 48. Each of the ends of the hub is formed with a socket 499, preferably rectangular in cross section to freely receive the squared' inner ends 45 of the shafts 45. liy sliding either of the shafts 45 outwardly endwise, either may ,be disengaged from its respective socket, to thus render the shafts incapable of being rotated by the gear. For the purpose of arbitrarily sliding either of the shafts endwise out of engagement with the gear, each end of the shaft housing is similarly constructed and equipped. Each end is'formed with a lug having a bore 49 extending parallel with the shafts 45, wherein is slidably mounted a rod 49, carrying at its outer end a composite separable link 49", which link is adapted to be inserted in the groove 46 to surround the hub of the fan wheel, to enable the latter to rotate freely therein. Thus, a longitudinal movement of the rod- 49 will result in bodily moving the fan wheel, outward and disconnecting its shaft 45 from the driven gear 48. For the purpose of enabling the oper ator to throw into or out of gear either of the fan wheels 46, from his position on the seat 18", I provide for each fan wheel a shifting rod 50, having a suitable handle 50, and being formed with a flat eye 51 at its front end. This eye (Figure 5) is movably positioned between a pair of lugs 51 of a shifting bracket, having a pivot pin 51 extending through said eye, and a stud 51" rotatably fitting in a hub 52, preferably integral with the housing 43. The shifting bracket has a downwardly extending lever arm 52 having pivotal connection 52" with a link 53, which link has pivotal connection53 with the shift rod 49.

By actuating the handle :50 to rotate the rod 50, obviously either of the fan wheels may be thrown into gear. Journaled by means of the bearing 53 in the housing 43, is a shaft 54, extending at right angles to the shafts 45, and carrying a pinion 55 in mesh with the gear 48. The shaft 54 carries rigidly, as by means of a set screw 55 at its rear end, a universal shaft connection 56, which in turn is rigidly connected by means of a set screw 56 to the motor shaft 18.

The universal connection comprises two substantially similar connecting members 57, each having oppositelydisposed lugs 57, which lugs are in transverse overlapping relation, each pair of lugs carrying a pivot bolt 57 between them, which pivot bolt has rigid connection, with a ball 58.

It will be noted, that the center of the pivot bolts 57", or the ball 58, are located coincident laterally with the pivots 22, so that the plow unit 25 may be bodily swung vertically about said pivots and universal joint. As the pivots 29 are carried by the plow unit by means of the extension bars 59, which bars are firmly secured by means of bolts 59 to the mold boards and the cross member 59", it will be apparent that the strut members 30- (Figures 1, 6, and 12) will be in compression, inasmuch as the weight 2 of the plow unit develops a pull in the links 23, thus placing these in tension, said unit tending to fall forwardly and downwardly because of the pivotal connections 27 between-the links and the mold boards. However, the rear of the plow unit is supported in elevated position by and suspended on the main frame 2, by the adjustment screws 38. Ubviously, the plow unit in its descent to the ground, must rotate about the pivots 22, and, therefore, in such rotation, tend to swing the pivots 29 rearward, as the latter are situated a considerable distance below the center of rotation. A rearward movement, however, of the pivots 29 is opposed by the struts 30, which latter abut against the rear axles 3 with their shoulders 33', thereby transmitting the forces due to the impact of the nose of the plow with the snow, through the extension bars 59 and the struts.

By means of the adjustment afforded by the plates 33 of the struts, as described in the foregoing, I am enabled to so adjust the effective length of the struts, as to bring the lower edge of the plow unit parallel with the roadbed, as indicated in Figures 1 vas said vertical plane corresponds ,to the base of a triangle of which the pivots 27 form the apex, it will be apparent that the pivots 29 will move an appreciably greater distance downward with each turn of the handles 40, than will the pivots 27. This 'lifi'erence in travel of the pivots will cause the front of theplow unit to travel a lesser distance than the rear thereof, inasmuch as the pivots 27 are located at the front por-' tion of the mold boards. This is clearly" illustrated in diagram 10, wherein the pivots 29 have rotated about the axles 3, from the position shown in solid lines to that indicated by the fine dotted lines. The pivots 27, in the diagram, it will be noted, are wpparated less than half the distance between t 1e is raised at its nose and lowered at the rear, but it is at times desirable to change the distance between the roadbed and the parallel lower -edge of the plow unit. To accomplish this, I have provided the adjustment plates 33, at the. rear ends of the struts. The plates 33 may be adjusted until the struts are of proper length to raise the plow to the desired height. The plow unit may then be leveled with the road bymeans of the adjustment screws 38. As the main frame vibra-tes more or less vertically, theshifting rods 50 are provided with a rotatable joint constituted in the pivot pins 51", so that the rod may bend in unison with the vibrations of the frame.

The mold boards 24 inchne rearwardly and converge forwardly, and extend laterally a distance beyond the side of the tractor. The forward surface of the mold boards is somewhat arcuate in form and is gradually extended circumerentially as the boards recede from the median ridge 24, to form semi-circular, oppositely disposed, laterally opening discharge funnels 60, the outer rims of the funnels being preferably in vertical parallel planes.

The fan wheels may be described as being formed with radial, outwardly and rearwardly pitched blades 61, triangular in shape, the peripheral inner corners of the blades being cut away to conform to the angle of divergence of the mold boards. The fan wheels are constructed to afford suf-- ficient clearance between the walls of the pivots 29. The plow unit, as shown,

funnels and the peripheries of the wheels, to permit of sliding the latter outwardly to effect a disconnection from the motor, as explained in the foregoing.

For the purpose of deflecting the snow to direct its delivery from the fan wheels, or, in other words, what may be termed snow ejecting devices, to remote oints along the roadway, I provide'a semi-circular coverplate 62 for each funnel, said plate having a port 63, located adjacent the upper portion of its surrounding edge. is provided at intervals along its edge with perforated outwardly extending flat lugs (33, adapted to engage flatwise with the inner side of the funnel. Bolt holes adapted to receive bolts (34 are suitably placed to engage said lugs, whereby the cover plate may be removably bolted in position. Each coverplate is provided with an outwardly and forwardly directed deflector or hood (35, said hood being secured in such manner to the plate as to surround the top and sides of the port 63, the hoods of each preferably formed of sections such as a, b, c, and are hinged together by means of thumb screws 65, whereby the sections may be set at varying angles to each other, to change the angle ofdeflection.

The adjustment screws 38 or what may be termed controlling means for controlling the position of the plow unit, are mounted on the links 23 and bar 59, at a point located a short distance from the pivots 22 and 29. This is done for convenience in construction, the screws being sufliciently loose in the openings 39 and 39 to permit the plowunit to climb an incline, independently of the tractor.

In Figure 10, 66 designates an incline, the nose of the plow being shown as sliding thereon, and the pivots 27 having been lifted from normal position to a point located a considerable distance above the same. Bodily lifting of the plow unit in th1s manner is rendered possible by constructing the rear ends of the struts to slidefreely on the axles 3 b providing the plates 31. To facilitate c imbing hillocks or humps in the road, I provide an adjustable shoe 67. The shoe comprises a flat bottomed plate, curved upwardly at its front end as at 67', and formed with a bifurication 68, adapted to receive the flange forming the edge of the ridge 24. A bolt 68 passes loosely through said flange and shoe to enable the latter to be swung in a vertical longitudinal plane. The ridge 24 is formed with a boss pierced by a vertically disposed bolt hole (38", adapted to loosely receive a bolt 69 having a collar 70, said collar being adapted to engage the under side of the boss, to hold the bolt against longitudinal movement in the boss, but permit limited lateral movement thereof in the hole 68".

Each coverplate The shoe is formed witha threaded lug 71, in which is threaded the bolt 69, whereby it will be apparent that the bottomof the shoe may be held at selective distances from the bottom of the plow unit, as indicated by dotted lines in Figure 1. Thus, in surmounting icy hillocks, the shoe will ride over the same, while the plow unit conformingly rotates about the pivots 22 and the universal joint 56.

In operation, the plow unit is properly leveled with the roadbed by operating the adjustment crank screws 38, it being apparent that the plow unit may be tilted laterally to conform to the crown of the roadbed by simply screwing one crank screw further in or out, as the case may be, than the other. This is an important advantage in snow plows. When it is desired to remove the snow from the left side of the road, the plow may be positioned to bring its center line to the middle of the road. The right hand shifting rod 50 is now operated to throw the right hand fan wheel out of gear. The hood is properly adjusted by means of the thumb screws 65', to throw the snow in the desired direction, one direction being indicated by the arrows in Figures 1 and 2. As the fan wheels rotate from above forward, the snow scooped up by the left hand mold board is forced through the port 63 into the arcuate chamber of the hood 65 and deflected by the latter to throw the snow a distance laterally away from the snow plow. Thus, in a heavy snow fall, half of the road may be cleared at a time, there by enabling the use of the full capacity of the motor to drive one fan wheel, I have found this to be an important advantage, in that a smaller tractor may be used, and better work performed, as well as efiecting a saving of time.

During a plowing operation, the nose of the plow may be quickly raised by operating either or both of the crank screws 38, to avoid bad places, such as frozen spots, and the like. The ability of quick and accurate ad'ustment, to raise or lower the plow unit ar itrarily at an easily accessible point at the side of thesnoW plow, as are the screws 38, is essential in snow lows, to render them practicable. By sliding the shafts 45 out of gear in the novel manner shown and described, I secure a. cheap, simple, and effective construction. By making the coverplates 62 readily removable, I am enabled to quickly prepare the plow for use on roads where throwing the snow to the side of the road is not necessary. This is a eat advantage in snow plows, as muc motive power is thus conserved.

I claim:

1. A device of the class described comprising a tractor, a snow plow propelled at the front thereof, means rigid with the front of said tractor carrying a horizontal pivot, means connecting said plow to said pivot, and means extending from said plow to the 1r-ear of said tractor and bearing against the atter.

2. In a snow plow, the combination with a trat tor having a driven shaft; of a plow element adapted to plow snow, operatively mounted on the front of the tractor and being formed with opposite laterally opening funnels, drivable snow ejecting mechanism operatively connected tosaid driven shaft to be driven thereby, said mechanism including a rotary snow ejecting device in each of said funnels, and controlling means in connection with said devices and said driven shaft for arbitrarily disconnecting either or both from said shaft.

3. A device of the class described comprising a tractor, a snow plow propelled at the front thereof, means rigid with the front of said tractor carrying a horizontal pivot, means connecting said plow to said pivot.

-1novable means connected to said plow and engaging the rear of said tractor, and means for varying the distance between the pointof connection of said last mentioned means with the plow and its point of engagement with the tractor.

4. In a snow plow of the class described, the combination of a power driven wheeled frame, a pair of links extending longitudinally from the front of the wheeled frame adjacent the top thereof, pivotal connections between said links and frame to enable the former to swing in a vertical longitudinal plane thereon, a plow unit pivotally connected at. its forward portion to the front ends of said links to swing in a vertical longitudinal plane thereon, and brace members extendi from points located near the rear of sald frame to said plow unit, and having pivotal connection therewith to hold the same relatively positioned with respect to the ground, and adjustment means for extending said brace members, for the purpose set forth.

5. In a snow plow, the combination of a motor driven wheeled frame including a driven shaft, a pair of laterally spaced links extending longitudinally from the front of the frame and having pivotal connection with the latter to swing in a vertical lon tudinal plane thereon, a plow pivoted to t e forward ends of said links to swing in a vertical longitudinal plane thereon, and brace members pivoted to the rear portion of said plow at a point located an appreciable distance below the recited pivotal connections of said links with said frame and ada ted to brace against a rear portion of saitf' wheeled frame and slide forwardly thereon, for the purpose set forth.

6. In a snow low, the combination of a wheeled frame liaving two forwardly exapproximately in vertical alinement therewith, and extending to the rear of the wheeled frame to brace against a portion thereof in a manner to hold the plow in plowing position, and manually operated means for arbitrarily varying the distance between said first named pivotal connections and those of said brace members.

7. In a snow plow, the combination with a power driven wheeled frame having a drivable shaft, of snow manipulating instrumentalities pivotally connected to the front of said frame to swing'in a vertical longitudinal plane thereon, said manipulating instrumentalities including a. plow formed with a nose for initially en aging the snow and rotary snow ejecting evices carried bythe plow having operative connection with said driven shaft to be driven thereby when the shaft is actuated, and brace members extending to a part .forming the rear portion of said wheeled frame to brace thereagainst and being located below the level of the pivotal connections between said frame and instrnmentalities, and being connected to the latter in a manner to be approximately in straight alinement with the nose of the plow.

8. In a snow plow, the combination with a motor driven tractor; of snow manipulatmg devices operatively assembled to coact when actuated to plow the snow and deposit the same at the s1de of the road, pivotally mounted on the front of the tractor to be swin'gable bodily in a vertical longitudinal plane thereon, said devices including a plow havlng a nose for initially engaging with the snow, and rotary snow ejecting devices operatlvely connected with the motor of the tractor be driven thereby, a .bar bracing endwlse against a part of the tractor near the rear end thereof and extending in the direction of the nose of the plow, and being approximately in longitudinal alinement therewith, and secured to said plow, a p votable jolnt in said bar located intermediate its ends, and manually actuated means for bending said joint toselective degrees and so holding the same, for, the purpose set forth.

- 9. In a snow plow, the combination with a tractor havin a frame resiliently mounted to enable the front thereof to vibrate vertically, and a. motor carried by said frame, in-

eluding a driven shaft; of snow manipulating mechanism pivotally mounted on the front of said frame to be swingable bodily vertically thereon during a snow manipulating operation, said snow manipulatmg mechanism including, a plow, braces extending from the tractor to the rear of the plow and being attached to the latter at points located between said frame and the ground, for holding the plow in operative plowing position, snow ejecting devices carried by the plow, having operative connection .withsaid driven shaft to be driven thereby, the pivotal connection of the plow with said frame, including links extending forwardly and having pivotable connection with the plow at a point spaced an appreciable distance forwardly and u ward y of the point of attachment of sai braces, for the purpose set forth.

10. In a snow plow, the combination with a power driven wheeled frame having a driven shaft; of snow manipulating instrumentalities pivoted on the front of said frame to swing bodilyvertically in a'longitudinal plane thereon, said instrumentalities including a plow, and rotarysnow ejectm devices operatively connected with sai driven shaft to be driven thereby, said snow ejecting devices includi laterally ahned fan wheels, one for each side of the plow, a supporting shaft for each of said fan wheels, extending in alined relation transversely of said frame, a gear train located between the .inner adjacent ends of said shafts and adapted to be connected with either, and having operative connection with said driven shaftto be driven thereby, and separate manually operated controlling means for each of said shafts for arbitrarily connecting either of the latter with said gear train.

11. The combination with a vehicle having a wheeled supporting axle at the rear thereof and a snow plow at the front thereof, a pair of laterally spaced links pivotally connected to said frame and plow, and a pair of laterally spaced links disposed, respectively, below said links pivotally connected to the plow slidingly engaging and abutting the rear portion of said I vehicle.

12. The structure set forth in claim 11, said latter links having flanges extending over the rear axle of said vehicle and slidable thereon, and shoulder portions extending substantially normal to said flanges abutting said axle. 13. The structure set forth in claim 11, and means for separating the points of pivotal connection with said plow of said mentioned links and said last mentioned 14. The combination with a. propelling vehicle, a snow plow connected to the front thereof, a thrust means connected to said plow and abutting against and longitudinally slidable on the rear portion of said vehicle to take the backward thrust of said plow 15. The combination with a propelled vehicle having a frame, an axle at the rear thereof and driving wheels on said axle, of a snow plow at the front of said vehicle, means pivotally connecting said snow plow to the front of said frame, and means swingingly connected to said plow and abutting said axle.

16. The combination with the propelling vehicle of a snow plow comprising a mold board having a Substantially pointed front portion and extending at each side of said portion, a pair of laterally spaced links connected to said mold board and said vehicle, a pair of laterally spaced links pivotally connected to said mold board and abutting said vehicle, means for moving said latter links to swing said mold board about the pivotal plow in front of said tractor movable about said pivot, an articulated connection between said plow and the rear of said tractor for moving said plow about said pivot.

18. A snow plow comprising side portions converging forwardly substantially in a point, a shoe adapted to engage and slide on the ground adjacent the front of said plow, a threaded member engaging said shoe and extending upwardly adjacent the front of said plow and adapted to be turned to elevate the front of said plow relatively to said shoe whereby the plow front will be supported on said shoe.

In testimony whereof I afiix my signature.

JOHN O. JOHNSON.

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