US2139625A

US2139625A - Plow

Info

Publication number: US2139625A
Application number: US108769A
Authority: US
Inventors: Hugo E Pruss
Original assignee: SNOW REMOVAL EQUIPMENT Co
Current assignee: SNOW REMOVAL EQUIPMENT Co
Priority date: 1936-11-02
Filing date: 1936-11-02
Publication date: 1938-12-06
Anticipated expiration: 1955-12-06

Description

5 Sheets-Sheet l H. E. PRUSS PLOW Filed NOV. 2, 1936 Dec. 6, 1938.

INVENTOR.

ATTORNEY.

Hugo ti P/ws fl/MW Dec. 6, 1938. i H. EQPRUSS 2,139,625

' PLOW Filed Nov. 2. 1936 3 Sheets-Sheet 2 Hugo L. Pram INVENTOR.

ATTORNEY.

Dec. 6, 1938. H E, R'US 2,139,625

now

3 Sheets-Sheet 3 FIG. /0

Hugo P/UJJ' INVENTOR.

QM WW ATTORNEY.

Patented Dec. 6, 1938 UNITED; sraeras- O F F LCE PLOW Application November-2,- 1936,: Serial :No: 108,769:

141 Claims;

This invention relates to plows- -whiclrareiat'-'-- tached to and drivenby ai vehicle; especially to road plows-, such snow plows, butfim'ay beapplied to ice, dirt or other similar ploWsL More t. specifically," the present invention is concerned with an improvement in the attachmentfor secur--- ing 'tliei plow' and-its supporting: frame to air-vehicle', such as a motor tmck or tractor.'- It is particularly applicable to-plows whi'ch-are' detachqv 'ably secured to motor vehicles; but' isalso appli cable to permanent installations.

It is known to attach a plow frame to a vehicle:

by means of a-pivot fixed to 'a part; of tlie vehicle, such as a truck axle, whereby the plow -can 'be 51i'swungupwardly to adjust the height; of the plow blade in relation'to' the ground, and-the 'depthto which the 'cuttingedge enters the -'snow or soil may thereby be controlled and the plow placed intoand out et operation; Such: a 'constmeti'on olds, for example, described in the United State's patent'to Hewitt'No. 2,0555'794) In suchade'vice the weight ofthe plow share orblade,--as' well as of the forward-endof the-frame, is carried-by running devices, such as one or more wheels aorgqsleds, attached to the forward end of the- -fram'e and the frame functions mainly' to='transmit ahorizontalforce to 1 pushthe plow into -'the ma-- terial-to be excavated, and to steer it-inthe-de si-reddirection. Whileiit' is customary to mount m theblade in front of the vehicle, it may also-be mounted in rear of it,

The horizontal thrust carried by the frame insuch constructions is considerable; and it: has

been necessary to provide a pivot bearing and. a.

;;frame structure of generous dimensions to insure the life of the bearing-and to prevent bucklingof the frame.

Insuch. a construction, moreover, the frame-is rigidly pivoted to the vehicle-so that whenever u-the vehicle is tilted laterally the plow-issimilarly tilted. This may occur, for example, when one tire is larger than the other tire on'the same-axle,

or when one wheel passes over'an obstruction, or enters a depression, or, when clearing snow or. other material from a-roadway','when one side ofthe truck is off of the pavement.

The tilting of the plow frame prevents the plow fromdigging.

the:groundri. These difiicultieszare; encountered in plows." whichrarevmounted; perpendicularto the longitudinalaids ofithezvehicle aswell 'asin plows. which are mounted diagonallywithrespect to; the saidaxisaa This'zdifficulty'has rin.the:past, -made,-1t.imprac-. tical' to mount the plow'frame to'asprung chassis,-. which isoften subject to tilting .withrespect to the: ground; duetoswaying 501' unequal loading, neces-\- sitatingqtheufasteningz of-the pivot and frame to the axle: of the :vehicler. Such' a: mountingis, however,.undesirable becauserit places an undue stressmpon-:theztruokraxle-andlthebracing-structure which holds ':the-.:axle in. alignment. to the truck, and-because insuficient space is. available near-theaide for. providing pivots and. frame membersaof the necessary strength;

As. further difliculty. encountered in: such. constructions; andaparticularly in? connection with; plow blades which,zlike that'shown in-lthe-I-Iewitt patent, above =referred-.to;. are disposed. diagonally with'respect to theraxisof the-vehicle and the. axis of I thepivotsfimthat .whens-the height ofthe plow is=adiusted.with.respect: to the g-round; or snow surface, both ends of the plow blade cannot be 25.:

made to rise the "same. distance. This is due to the-fact that both; ends. of the blade are. pivoted about the same'pivot a-xis sothat the. end of the plow-the farthestzremoved fromthevehicle, due to its longer radius',.'swings through a greater. vertical distance than the otherend of the blade. It, for example, the: rearward runner of such a push'plowemployed to-remove: snow passes over atmoundof snowandisltherebylifted, the leading runner, instead of remaining-on. the surface, will be lifted through a vertical distance which is greater than the: lift on the rearward runner, placing; aftorsional stress on: the frame and preventing effective removal ofpsnow from; the area traversed by the leadingend-of the blade. Simi- Ian difficulty iszencounteredwhen the blade is intentionally raised orlowered.

Still. another difficulty encountered in plows. which are diagonally mounted with respect tothe vehicle and frameis that the forward end of 45, the frame canbe maintained in its proper vertical position. with. respect to the ground or .snow only when thelpivot axison-the truck is at the correct height above-the ground.- When the-tires on the truck-are changed, or .when. thetruck-moves over rough ground, the axle or chassis. frame is .higher or lower. than.- the height for; which the frame was designed, and thedifficulties describedin the preceding paragraph are also encountered. This circumstance, moreover, makes it impossible to attach the plow frame to a vehicle other than the one for which it was constructed. Broadly, the present invention contemplates the provision of a novel and improved plow frame particularly adapted to be attached to a vehicle which is capable of moving the plow forwardly and maintaining it in its proper direction of travel, while permitting the plow to assume its proper positioning with respect to .the ground or snow surface irrespective of the height or lateral.

inclination of the vehicle or the relative vertical position of the supporting runners.

It is an object of the invention to provide an improved means for attaching a plow frame to a vehicle which may be attached toa. sprung portion, as well as to an unsprung portion of the vehicle, and which will permit the vehicle to 'move over rough and irregular ground. It is a further object to provide a novel and improved attaching means which will permit the plow to be attached to vehicles of different heights above the ground, and to operate efiiciently regardless of variations in the height of the vehicle axle or chassis with respect to the ground.

A further object of this invention is the provision of a means for attaching the plow frame to a vehicle in a manner which will permit the end of the frame nearest the vehicle (either forwardly or rearwardly) to have a constrained vertical movement with respect to the vehicle. A further object is to provide a. plow frame which is better able to transmit horizontal thrust to the vehicle and have a lesser tendency to buckle than the frames heretofore employed.

Still another object of the invention is the provision of a plow frame having a diagonally disposed plow blade which-may assume its proper position with respect to-the ground or surface of the snow, irrespective of the lateral inclination of the portion of the vehicle to which the frame is secured. A further object is to provide a plow frame which may be attached to a vehicle so as to have free lateral tilting and vertical as well as vertical'tilting movements with respect to the vehicle.

The above and additional objects, which will hereinafter be more specifically treated, are attained by such means as are shown in the ac-' companying drawings, described in the following specification, and more clearly pointed out in the claims. While I have in the following specification described only four specific embodiments of the invention, and have described these with sufiicient detail to enable those skilled in the art to which it pertains to understand the mode of construction and the principles involved, it is to be understood that there is no intentional limitation to the specific forms and precise details shown, and that various modifications of the same can be resorted to without departing from the spirit and scope of the invention, and without sacrificing the benefits derivable therefrom. It is also to be understood that certain features of the invention herein disclosed may be employed in and with other combinations than those shown and described.

The invention will be described as applied to a snow plow of the general type shown in the Hewitt patent, above referred to, it being understood that it may be employed in connection with the rotor shown therein, or without it, and that persons skilled in the art of excavating can make such modifications as are necessary to adapt the invention to other purposes. In the drawings:

Figure 1 is a fragmental side elevation of a snow plow comprehending the present invention, as it would appear when operatively connected to its correlated automotive vehicle, the plow blade being shown partly in section.

Figure 2 is a top plan view thereof.

Figure 3 is a horizontal section taken on line 3-3 of Figure 1, illustrating the mounting of the frame to the transverse girder or bolster. Figure 4 is a transverse section taken on line 4-4 of Figure 3 in the direction of the arrows.

Figure 5 is an elevation view of a pump employed to operate the lifting ram.

Figure 6 is an enlarged fragmentary perspective view illustrating the preferred mode of supporting the transverse bars and girder on the side abutment plates which ar e attached to the vehicle.

Figure 7 is a transverse section taken on line 1-! of Figure 2, illustrating the mounting of g the transverse girder.

Figure 8 is a fragmentary side elevation of a modification of a portion of the frame and attaching means.

Figure 9 is a horizontal section taken on line 9--9 of Figure 8.

Figure 10 is a fragmental horizontal sectional view,-partly in elevation, similar to Figure 3. showing a further modification of my invention.

Figure 11 is a transverse section taken on line ll-ll of Figure 10 in the direction of the arrows.

Figure 12 is a horizontal vertical view taken on line |2l2 of Figure 10.

Figure 13 is a fragmental horizontal sectional view, partly in elevation, similar to Figure 3, showing still another modification of my invention.

Figure 14 is an end view of the construction shown-in Figure 13.

Referring to the drawings, and particularly to Figures 1 to 7 thereof, Iil is the sprung chassis of an automobile or similar vehicle, which may be provided with springs, not shown, and having an engine compartment H and wheels [2. A pair of abutment plates I 3-l3' is secured to the chassis by detachable bolts, as shown. The abutment plates are spaced apart and rigidly connected by a pair of transverse channel bars l4-|4', with vertical webs, and a third channel bar l5, welded or otherwise secured to the inner faces of the plates I3-I3'. The bars 14-44" are provided with a removable pin or bolt l6. braced by a bushing 11, and forming a trunnion rotatably supporting a tiltable bolster 18, located between the bars l4, and extending through notches [3a, cut in the plates I 3-[3 (see Figures 6 and 7). The notches have vertical dimensions to permit the bolster I3 to tilt in a vertical plane about the pin l6 through an arc of about 10 to 15 degrees on either side of horizontal. The vertical faces of the notches are smooth, and are preferably provided with bearing surfaces by welding face plates I 9-l 9' thereto (see Figures 3, 6, and 7). The plates l9-I9 are located to engage the forward and rear edges of the bolster I8, so as to prevent its rotation about a vertical axis, thereby forming abutment means to transmit longitudinal stress from the chassis I0 to the bolster.

A rigid tower 20 is mounted on the abutment plates' l3l3, braced by tie rods 2|-2I, and provided with resilient supporting means and hoisting means, hereafter described.

The details on each end of the bolster I 8 are videia 'vertial'. groove on its outer face; A 'verendof, the} ter'fltliis' 'apai'rIof forwardly'ex;

bers'sof the plowsupporti'ng fram'L' A plurality l"of ,holes'.21 is'providedinithe' bars for receivingan adjustable 'pi ri 128'; adaptedto, rest on the upper edge of the plate .2 4,t01i1nit the, downward movementjoff the ba'r125 in' its groove.- A

.. ,se 'c oiid' pin'129 may, if desired, be similarly infzdser ted inahole below the plate 24 to limit the upward travel. If desired, the pin's"28 arid,,23 may be located so as' entirely to'p'revent a slid ing motion, v A struts 26 may be suitably reinforced "aga inst buckling,an d provided with a transverse bar30, The forwardends' of the struts are curved to fit the rear surface 'of' a plow blade 3|, ,to which they may be fi$edly1secured,'as' shown,

but towhi ch theymay be attachedin the manher illustrated in Figures lfto" 3 jand 7, of the. Hewittpatent, referredtd above. I The weight The. midway point'b'etweenftlie ribs 31' s1 is generally ofi-center, and locate'd'so'as tobalarice ,gtheweight of the frame and plow when the same are swung upwardly about the journals 22 to place'the plow. out of operation, or, during, operation, to elevate the blade to clear an obstruction' or to make a shallower cut into the snow. 6 The ram 36 may be operated by a hand or motor driven pump 38, preferably operable or controllable from the driver's compartment of the truck, andlconnected to the ram by means of fluid pressure transmitting tubing 39. The ram and g 'its attaching means are so constructed as to permit the frame to be tilted upwardly through an angle of about 30 degrees above horizontal. While the ram may be employed to raise the .blade during operation .asstated above, it nor- 0 m'aIly, supports no weight when the plow is resting. on' the runners. 32 -32'.

According to the novel means for supporting the plow and its framelwhen in operation conternplat edir'i one embodiment of the present ins'vsno'omme, weight of these parts is carried by three points: The two runners 32. and 32' support thewei'ght of the front portion of the structure; the rear portion, of the frame is supported from the tower 20, by acable 40' which is pref- 7 erabl'y providedwith a turnbuckle" 4| and a coiled spring42. r.,s1mnar, resilient means for restraininglys lpportin'gfthe rear end of the frame; but the resilient s'pringmay, if desired, be omitted. .Th po nrorattachment ofthe cable 40 is gen- 75 erally ofi-cntiffand is'preferably so chosen,

arse-see af'circular' disc. or jourrial" 22, revolvably' w I The'bearing" 5 member'23'iis"fiiedfto'ja plate 24, haped to pro;

edly' saatsafmss has 2% its on j each" A hydraulic or oil ram is'suspended from and thelefi th I th thesprin'gfarejsueh, 'th the weight of the rear enjd" offthejlfra'mej, is"b a1'a d' with respect to the" runners 324-321.; Infith'is manner no weight is,fduring"jt he normaljoperation',"carried by the 5 pins; 28' a d"29,',"these"plnsjserving merely as safety gleyic'es 130, h'ol the1resi1ient g I v hasajrestrained yertieaim'overi ent with respect tof'the 'truckf aiidflexibllityland j stability are insuredfv fljhe' three: polnt' support, moreover, (whether'brintfth'e' cage is provided with a 15 resilient means); make'sjit possible for both of the"runners""32 32 to'"be 1n"conta ct with the ground pr snqw surface, regardless fof the relative eievandrisiqi' he., i1r; s e suppor n these nner's, and"irrespctiveof the lateral tilting of the 20" truck. We

If, fo r e rampl; 'thxi truclris tilted laterally with respect'lto' the""runners"or the frame, the framefis'free'to tuijn abdQtQajstibStantially longitudinal'axjsjjbing supporte'd onlyby the cable 25- 491 The struts" 28, jbeing"a1 part of' the frame, will in t is Case transmit the transverse turning motion tothefbolster"l.8lby fmearis'of the bearings' 23 'and j ournalsj2 2f; ,butjthis' ibolster is free to pivot about'tlie; n "pinltiand'torsional stresses in the fr 7,

re taurant; no ,;,t lthefl cablejll is not ndisp ns bl j nestmiqh 'asf he we t o the rear endof the'fraine'c ri'alsofbe supported by the ram '36, which may b attached to the frame at ajpoint to adapt'itito'perform'both the function'of lifting'the fram'e aboutthe' journals 22 when it is desiredto swing; the blade'iil upwardly, ancllthetunctiqn abdve described for the cable 5p; Einally;itflis" also possible to dispense entirely with a pen'dant suspension means for the' rear end of the'frame durin fihe normal operation (thereby eliminatiriglthe cable All and either eliminating also the rarh36 and tower 20, or employingthelatter only for swinging the frame upwardly) and toca'rry the weight of the rear end of the frame by means of the pins 28, journals 22, and the trunnion pin 16, in which case the pin l6 will functio n as the third point of support and'a three point of suspension will 0*" be realized.

It should also be noted that the relative vertical slidinginotion' between the bar 25 and the plate 24 improves the flexibility of the device,

particularly when e cab e! is employed, since it prevents the tr'ansmission' of a substantial amount of vertical thrust from the frame to the bolster 18' and' the' mdfiQ f vehicle, This relative sliding movement" is also of advantage whether or not thecable 40 is employed, since it permits 66" the abutment plates 3 -Ql '3' t be attached to motor vehicles of difiernt heights without requiri'ng a reconstruction of the frame and struts 26, the

pins

28 and 29 being merely inserted into the proper holes, ever, not'jndispens'ableto the operativeness of the device, inasmuch as it' is possible to carry the weight of the rear end] of the frame by the trunnion pin l6, as pointed; out above, and yet prevent torsional stresses in the frame. In this 78 case the struts 2$"xnay be' fixedly attached to the plates 24 or the pins28 and 29 may be adjusted to prevent a relative vertical sliding movement between these parts. V

During the operation-6r the plow the horizontal 76 The sliding motion is, howstress is completely transmitted from the frame by its struts 26 to the bolster l8 and from the bolster [8 to the abutment plates |3l3 by the abutment of the front and rear edges of the bolster on the vertical faces of the notches I 311 in the plates Iii-I3. This arrangement at the same time maintains the frame in the proper directional alignment with respect to the vehicle. Since the vertical edges of the notches in the plates |3-|3' carry considerable stress it is desirable to reinforce these plates and, moreover, to increase the rubbing surface beyond the thickness of the plates. This may be effected either by mounting the bars I 4-H so close together that the bolster bears against their inner faces, or by attaching the smooth face plates l9--|9' on the vertical edges of the notches l3a, as described above.

When it is desired to detach the plow and frame from the vehicle it is only necessary to pull out the pins I6 and 29 and to disconnect the cable connections depending from the tower 20.

The bolster 18, together with the journals 22, bearings 23, and plates 24, may then be slid downwardly and out of engagements with the plates |3-|3 and the bars 25. Alternatively, the pins 16 may be left in position and only the pins 29 removed, the struts 26 and the bars 25 being then lifted out of engagement with the plates 24. The plates [3-[3 may then be readily unbolted from the truck chassis. It will be noted that the frame is very rapidly and easily attached to and removed from the vehicle. If desired, the plates l3-l3' may be left on the vehicle during the winter season, thereby still simplifying the operation of placing the plow into operative order. Moreover, the plates |3-l3 and its tower may be employed with a dirt plow in certain seasons, and with a snow plow in other seasons.

In the slightly modified form of the attaching means shown in Figures 8 and 9 the struts 26 are further braced against buckling and the stress on the journal is reduced materially. In these figures parts corresponding to those described above in connection with Figures 1 to 'l are indicated by like reference numerals. The abutment plate l3, its face plates I9-l9, the bolster 18, the plow frame and its supporting runners and cables are each similar to those of Figures 1 to 7. A vertically elongated bar 44 is fixedly attached to each end of the bolster I6, and is provided with a plurality of holes 45. A slide 46 having inwardly projecting guides 4l4l' and flanges, as shown, is arranged to have a vertical sliding motion with respect to the bar 54. The vertical dimension of the slide 46 is less than that of the bar 44, and the vertical movement of the slide 46 may be limited or prevented by means of

pins

48 and 49 which may be inserted into the holes 45.

The outer face of the slide 46 is provided with a journal or pin 50, passing through a horizontally elongated hole or slot 5| in the thrust member 52. The member 52 is fixedly attached to the strut 26 or may be formed integrally therewith. The plate 26 is attached to the plow blade at its forward end as shown in Figures 1 and 2. The inner face of the member 52 is provided with an arcuate flange 53 having its center of curvature at the center of the journal 56. A coacting arcuate flange 54 is formed on the slide 46 and is shaped to fit the inner face of the flange 53. The slide 46, together with the flange 53, constitute a second thrust member.

Since the slot 5|. extends longitudinally with respect to the member 52, it will maintain the member 52 in its proper vertical position with relation to the slide 46; but horizontal thrust is carried entirely by the contacting faces of the

flanges

53 and 54. As a result of these flanges the stress on the journal is greatly reduced, and the length of the member 52 through which the horizontal stress is carried is shortened, thereby reducing the tendency to buckle. Moreover, the flange 53 has an appreciable vertical dimension and the member 52 can, therefore, be more easily reinforced to transmit horizontal force.

The modes of operation of the embodiment illustrated in Figures 8 and 9 are similar to those described above in connection with Figures 1 to 7. It should, however, be noted that the coacting arcuate flanges may also be employed in connection with other forms of plows which do not comprise the tiltable bolster and/or the vertical slide. Thus, the thrust member 46 carrying the journal 56 and the flange 54 may be attached directly to the chassis of a vehicle.

In the modification illustrated in Figures l0, l1, and 12, the bearings and

journals

22 and 23 are eliminated by employing a circular transverse bolster 55 rotatably mounted in slides 56-56. The slides 56-56' are mounted to engage the vertical edges of a notch 51a formed in abutment plates 5'l-5l', which are similar to the abutment plates l3l3' shown in Figures 1 to 7, and which may be similarly attached to the chassis of the vehicle and similarly braced by channel bars 58 -58.

The bolster 55 may be retained by means of a pin or trunnion bolt 59 extending between the bars 58-58' and through an elongated hole 66 in the bolster 55, the hole being shaped to permit the bolster to rotate about its axis through an arc of about 30 degrees or less. The bolster is laterally tiltable about the pin 59 through an arc of about 10 to 15 degrees on either side of hori zontal. The slides 5656 are thereby prevented from moving out of the notches.

The slides 56-56' are provided on their front and rear faces with a pair of grooves Gl-Bl to receive the walls of abutment plates 5l5l. The bottoms of the grooves are plane surfaces spaced so as to engage the vertical edges of the notch 51a (see Figure 11); the side faces of the grooves are curved, as shown in Figure 12, to engage the side walls of the plates 5l-5'." when the bolster is tilted laterally about the pin 59.

A vertically elongated bar 62 is fixedly attached to each end of the bolster 55, and provided with a plurality of holes (not shown, but similar to the holes 45 in the bar 44 shown in Figure 8). A slide 63, having inwardly projecting guides 64- 64 and flanges, as shown, is arranged to have a vertical sliding motion with respect to the bar 62. The vertical dimension of the slide 63 is less than that of the bar 62, and the vertical movement of the slide 63 may be limited or prevented by means of pins 15, as described above in connection with Figures 8 and 9. Struts 55-65 (corresponding to the struts 26-26 shown in Figures 1 to '7) are fixedly secured to the slides 63, and form the sides of the plow frame.

The modes of operation of the embodiment illustrated in Figures 10, 11, and 12 are similar to those described in connection with Figures 1 to 7. When the plow frame is swung unwardly to clear an obstruction or to place the plow out of operation the bolster 55 rotates in the slides 56 56 and about the pin 59. Otherwise the function of the device is identical, i. a, it may be supported mythepable kfl, or -the weight of the rear portion fiftheframe may'-be:carried by the trunnion pin W59.

Ih the embodiment shown Figures 10, 11, and I2 'the =downwardmovement' of the'slides' 56--56' -may 'be limited by stirrups "ll attached 'to the =plates 5 l- 51' asshown, andthe en'dwisemove- -mentof the bolster in the slides may be limited Jbymeans of *pinsGB-JSB. (A limited endwise m0tion-is necessary.) When these added features are provided, the trunnionp'in 59 may in certain cases be omitted.

Accordingto the fourth modification, shown in Figures 13 and 14, a bolster in the form of'a continuous transverse girder may be omitted. In thesefigures, abutmentplates-fi'l- -tl', carried by the chassis of 'the vehicle, are provided with 'slides 68*68-and with stirrups- 69 to limit the downwardmovement of the slides,-all as shown in Figures 1-0, 11, and 12. Rotatably mounted in -each sli-de 68'is-a'heavybolster pin 10, provided wir'ith a' nut 72 to have a limited endwise motion. struts' l-3 'l3', forming the side plates of the plow frame, and -.corresponding to the struts 26* '16" of Figures" I to 7 are fixedly secured to the pins 10 in-"this modification, :the frame may be -swung upwardly by' rotation of the pins"!!! in the slides -6868. These slides may float between their =u-pperandlower-positions when the rear end pf the frame--is--supported -'by the cable 40; when *this 'is not employed, they-may rest on the stirrups 69,'=which=may be provided with an adjustablebolt H' 'to Jimit the downward movement.

When the plow frame is tilted laterally one slide moves verticrlly-withrespect to the other, :thereby preventing torsional stress in the frame, andzmaintainingithe plow blade in its proper position with'respect to the ground.

.Inciaim as my invention:

1. The combination with an automotive vehicle of a transverse bolster attached to said vehicle rotatable in a substantially vertical plane transverse to the vehicle and secured to transmit longitudinal thrust to said vehicle, a plow frame extending longitudinally from one end of said vehicle having a plow attached thereto at one end thereof, slide means interposed between the other end of the frame and said bolster arranged to permit said other end of the frame to be adjusted vertically with respect to said bolster, means to lock said slide means in an adjusted position, said bolster being arranged and constructed to permit said frame to be swung upwardly about a horizontal transverse axis at the second end of the frame.

2. The combination according to claim 1 in which the bolster is supported at a point intermediate its ends by a trunnion pin disposed longitudinally with respect to said vehicle.

3. The combination according to claim 1 in which the said second end of the frame is nonpivotally attached to the bolster by the said slide means, and the bolster is rotatable about its own axis.

frame extending longitudinally from one end of said vehicle hav-ing a 'plow-"attached thereto at cone end thereof, and a pair of struts extending to the other endpslide means interposed between said struts and 'said bolster arranged to permit :said struts-to be moved vertically with 'respect to said bolster, said slide means=comprising two -juxtaposedvertically extending members,- a pmralitysof-rperforations in at least ai first of said members, and P removable pin means extending through sa'id perforated-first member engageable with "the second member to limit'the vertical movement between said "members, whereby the height' of said struts with respect to the'bolster 'rnaybe a'djusted.

*6. A plowcomprising-a pair of laterally spaced :abutment plates and :an intermediate longitudi- '-nally' disposedtnunnion'adapted tube-attached FtOlWlIIlOtOIWGhiGlE, .a' transverse bolster rotatable m'boutuits 'zownr axis sand -pivoted about the trunniomaxis, and z'anplow'frame mounted-upon said ibolstenf-each of: said-abutment plates being-providedwitha substantially vertical face-near said :bolster and in thrust transmitting relationship thereto, whereby longitudinal thrust fromsaid :plow .frame maybe transmitted through .said :bolster: tossaidrabutment .plates.

7. :Aplowrcomprisingraipair of laterally spaced tabutment plates: andan intermediate longitudinally disposed-trunnion pin-adapted tube attached to=a .motor vehicle, a transverse bolster, a longitudinal, wertically elongated .-hole in said .bolster said trunnion pin passing through said hole, whereby .-said bolsterv is supported and .is trotatable about-its 'own taxis; and pivoted about the axis of the trunnion pin, each of said abutment plates .being provided with :a substantially vertical :faceznear @said bolster .and .in thrust transmitting .-.relationship thereto, whereby longitudinal-thrustfrom said :plow framemay be transmitted .-.through.'.-said bolster to said abutment plates.

8. A plow comprising a pair of laterally spaced abutment plates and an intermedite longitudinally disposed trunnion adapted to be attached to a motor vehicle, a transverse bolster rotatable about its own axis and pivoted about the trunnion axis, a plow frame mounted upon said bolster, each of said abutment plates being provided with a substantially vertical face, and a slide near each end of said bolster revolvably housing the same and in sliding engagement with faces in said abutment plates, whereby longitudinal thrust from said plow frame may be transmitted through said bolster and slides to said abutment plates.

9. The combination with an automotive vehicle of a pair of spaced plates attached to the frame of said vehicle, said plates having vertically disposed notches, a bolster extending transversely with respect to said vehicle and through said notches, mounted to be rotatable about the longitudinal axis of said vehicle and to slidably engage the vertical edges of said notches, a plow frame having a pair of side members, pivot means for connecting one of said side members to each end of said bolster, whereby said frame may be swung about the axis of said bolster, and a plow blade attached to the end of said frame remote from said bolster.

10. The combination with an automotive vehicle of a pair of spaced plates attached to the frame of said vehicle, said plates having substantially vertically disposed edges, a vertically movable slide on each of said side plates engaging said edges, a bolster extending transversely with respect to said vehicle rotatably mounted in said slides, a plow frame having a pair of side members, means for attaching one of said side members to each end of said bolster, and a plow blade attached to the end of said frame remote from said bolster.

11. The combination with an automotive vehicle of a pair of spaced abutment plates attached to the frame of said vehicle, said plates having substantially vertically disposed edges, a bolster extending transversely with respect to said vehicle mounted to be rotatable in a substantially vertical plane transverse to said vehicle and to transmit longitudinal thrust to the vertical edges'of said abutment plates, a plow frame having afirst thrust member extending forwardly from said vehicle on each side of the frame, a plow blade attached to the forward end of said frame, and means at each end of said bolster for rotatably connecting the rear end of said frame about a pivot axis substantially parallel with the axis of the said bolster comprising a second thrust member carried by said bolster and extending forwardly from said pivot axis, a pin substantially at said pivot axis carried by one of said members and extending through a longitudinally elongated slot in the other of said members, a first arcuate flange carried by said first thrust member having its center of curvature at said pivot axis, and a second arcuate flange on said second thrust member in engagement with said first flange, disposed so as to transmit longitudinal force from said plow frame to said second thrust member between said flanges.

12. The combination with an automotive vehicle 01' a plow frame having a first thrust member and extending forwardly from said vehicle, a plow blade attached to the forward end of said frame, and means for rotatably connecting the rear end of said frame to the vehicle about a pivot center comprising a second thrust member carried by said vehicle and extending forwardly from said pivot center, a pin substantially at said pivot center carried by one of said members and extending through a longitudinally elongated slot in the other of said members, a first arcuate flange carried by said first thrust member having its center of curvature at said pivot center, and a second arcuate flange on said second thrust member, in engagement 'with said first flange, disposed so as to transmit longitudinal force from said plow frame to said second thrust member between said flanges.

13. The combination with an automotive vehicle of a plow frame movably attached to one end of said vehicle and extending forwardly therefrom, thrust transmitting means for transmitting longitudinal force from the frame to said vehicle, a plow blade mounted at the forward end of said frame diagonally with respect to the axis of said vehicle, a plurality of spaced runners near the forward end of said frame for supporting the plow with respect to the ground, and supporting means attached to the vehicle forming a single point vertical support for the rear end of said frame comprising a bolster fixed to the rear end of the frame and disposed transversely with respect to said vehicle, a longitudinal, vertically elongated hole at an intermediate point in said bolster, and a longitudinally disposed trunnion pin carried by said vehicle passing through said hole, whereby said bolster is supported by said trunnion pin and may rotate about the trunnion axis and about its own axis.

14. The combination according to claim 13 in which the bolster is adjustably secured to said frame by means permitting vertical adjustment between the bolster and the frame.

HUGO E. PRUSS.

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