US2315007A

US2315007A - Rotary excavator

Info

Publication number: US2315007A
Application number: US327534A
Authority: US
Inventors: Leslie G Morse; Arthur R Hill; Charles C Morse
Original assignee: Individual
Current assignee: Individual
Priority date: 1940-04-02
Filing date: 1940-04-02
Publication date: 1943-03-30
Anticipated expiration: 1960-03-30

Description

.Marh 30,'1943.' L; G. MORSE ETI-I\L ROTARY EXCAVATOR 3 Sheets-Sheet 1 Filed April 2, 1940 IN VEN TORS:

A. d/Ifo/JJ A TTORNEX March 30, l943- L. G. MORSE ET AL 2,315,007

' ROTARY EXCAVATOR Filed April 2, 1940 3 Sheets-Sheet 2 7/ m '14 INVENTORS:

- i CC M251;

ATTORNEY March 30, 1943. L. G. MORSE ET AL ROTARY EXCAVATOR Filed April 2, 1940 3 Sheets-Sheet 3 INVENTORS:

v ATTORNEY Patented Mar. 30, 1943 ROTARY EXCAVATOR.

Leslie G. Morse, Randolph, Arthur It. Hill, Brookileld, and Charles C. Morse, Randolph, Vt.

Application April 2, 1940, Serial No. 327,534

- Claims.

The invention has for an object to present improvements in rotary snow plows, and in particular to evolve novel features of functional importance to improve the action of such devices.

It is a particular aim to enable the production oi such an article readily in a small size to be used for clearing sidewalks and adapted to be embodied on a small pedestrian-guided power tractor, although it is also adapted to be constructed in larger sizes and for connection or incorporation on four-wheel or other large tractors.

An important aim of the invention is 'to present such a device which is adapted to deposit snow immediately beside the cleared path when necessary, as well as to throw it to a great distance, so that the device is well adapted to use in urban areas, whereas the ordinary rotary plows are so constructed and so operative that they are not well adapted to such use, although they may be satisfactory in country areas, as far as the deposit of snow is concerned. This invention is consequently highly desirable for sidewalk clearing without throwing the snow promiscuously, which would involve covering or soiling of lateral wall ss, windows, or other areas and structures.

A special aim is to present a machine of this kind which is adapted to operate effectively with low power operating the rotor, due to special novel features in construction and arrangement of parts.

It is also an important object to present a. novel coordination of a simple two-wheeled tractor and the attachable plow unit to the end of assuring the proper fit of the plow element to the pavements being cleared, throughout undulations, affording support to the tractor power plant in a novel way. and permitting lifting of the plow manually with a minimum of eflort.

It is an important aim to present a novel coordination of a rotary snow thrower and a plow shoe, with respect to the path to be cleared and with respect to the tractor device.

A further important object is to present a novel construction in the snow-throwing rotor, and in the construction of the plow shoe or pusher. 1

It is also an object to present an attachable rotary plow unit which may be readily attached and detached from a tractor.

Additional objects, advantages and features of invention reside in the construction, arrangement and combination of parts involved in the embodiment of the invention, as will be understood from the following'description and accompanying drawings, wherein Figure 1 is a front view of a plow unit constructed in accordance with the invention, in operative position as it would be when connected to a tractor.

Figure 2 is a right hand side elevation of a complete coupled tractor-plow unit as heretofore constructed; parts of the tractor power plant and of the plow power plant being shown in outline only and part of one wheel being broken away.

Figure 3 is a similar view of the tractor-plow from the opposite side with the rear portion of the tractor broken away.

Figure 4 is a top view of the plow unit.

Figure 5 is an enlarged front elevation of the rotor.

Figure 6 is an edge elevation of the rotor.

Figure 7 is a detail of the pivotal connection of the plow unit and tractor, showing the spring connection between the tractor frame and plow unit.

Figure 8 is a diagrammatic view of the tractor and plow unit connections and having another relative position of the two dotted to show the nature of the relative movement of the two in accommodating the plow to curved pavement surfaced or variously inclined surfaces.

Figure 9 is a detail of one of the runner shoes and its adjustable mounting on the plow unit.

The tractor There is illustrated a part of a standard tractor unit commercially available, including of the running gear, however, only the rear or tractor wheels 20. These wheels support in the usual way an internal combustion power plant-transmission unit 2|, steering handles 22, and control and gear shift levers 2324 on one handle. The center of gravity of the power-transmission unit in this instance is preferably rearwardly of the axis of the wheels 20, so that a partial counterbalance is thereby provided for our attachable plow unit, and enabling our plow unit to be lifted from the ground by downward pressure of the operator on the handles 22. The tractor unit has fixed thereon at each side a pivot plate 25 in which a heavy pivot stud or bolt 26 is engaged, serving as the main connection between the tractor unit and the plow unit, as will be described. The tractor unit also has mounted on its forward end a forwardly projected flange bracket 21 serving as part of a compensating resilient support for the front of the tractor unit and lift for the plow unit as will appear.

Plow frame and power unit The plow unit comprises a rigid body frame work 30, which may be variously designed, but in the present instance includes two main lower side members 3| which extend rearwardly beside the pivot plates 25, and carry bearings 32 in which the bolts or studs 25 are engaged. At the forward part of the frame 30 there is included a channel girder 33 set transversely across the forwar extremities of the side members 3| in the present instance at right angles to the fore-andaft axis of the tractor. It is disposed with its body or web in a substantially vertical plane, and its top and bottom flanges 34, extending rearwardly. The bracket 21 extends close to the web of the channel member for relativevertical movement, and includes a transverse flange portion against the underside of which there is engaged a coiled load supporting spring 36 seated on the lower flange 35 of the channel member, while over the bracket flange there is a coil spring 31, which may be of lesser vertical extent and may be of less strength but is preferably under some compression between the top flange 34 of the channel member and the bracket 21 at all times. A vertical shaft 35 is fixed removably in the flanges 34, having a cotter pin through each end in the present instance. It is engaged loosely and axially through both of the

springs

35 and 31 and slidably through the bracket 21 which is properly apertured for the purpose. The frame 30 includes a top bed portion consisting of two members arranged transversely of the machine in the present instance and longitudinally slotted to receivefastenings 43 of the base 33 of a conventional power plant 40, preferably including an internal combustion motor, intended to operate the rotor or snow thrower of the plow unit independently of the power plant of the tractor unit. The details of this power plant comprise no novel part of this invention, and are not shown, it being sumcient for it to have the normal controls by which it may be set in operation to drive the rotor of the plow at a speed appropriate to the nature of the material to be excavated. It includes a main shaft projected forwardly and having a pulley 4| in a plane parallel to the web of the channel member 33 and rearwardly of the plane of the rear edges of the fianges34-35.

The channel member 33 projects a considerable distance to the right from the side members 33, and beyond the track or path of the right hand wheel of the tractor unit, and spaced to the rear of this laterally projected end of the channel member there is mounted as a fixed part of the frame 30 a shorter section of similar channel stock 43, parallel to the first and projecting across the path of the adjacent wheel. In the present in stance it is welded to an upright 42 of the frame which supports one side of the bed portion 38 of the plow'power plant. To assure the rigid parallel relation of the two channel pieces they are connected at top and bottom at their outer parts by tie bars 44. In bearings 45 of appropriate design fixed on the webs of the two channel members, a rotor shaft 45 is journalled, on

which there is fixed a large pulley 4I alined with the pulley 4 I. In the present instance, these pulleys are shown as having a plurality of grooves, and they are connected by a corresponding number of v-belts 48. For adjusting the tension of these belts the base 39 may be slidably adjustable on the bed 38and secured adjustably by the usual bolts 49 by which the base is clamped to the bed 38.

It should be noted that the plow unit power plant is disposed centrally with respect to the longitudinal axis of the tractor unit, and that the bed portion 38 is extended rearwardly from the supporting frame 30 so that the center of gravity of the plow power plant is located over the trantor power plant and the weight forwardly of the wheels 20 is minimized as much as practicable.

Rotor housing and chute Fixed to the shaft 48 there is a rotor 50, around which a casing 5| is built, including a concentric lower peripheral wall 52 which extends with auniform width for approximately 190 degrees around I, the path of the rotor, although this may be varied without materially affecting the operation of the machine. This peripheral wall is joined fixedly to a rear or back planiform wall 53, which is secured to the channel member 33. A' vertical continuation of the wall 52 stops short and forms a. right hand horizontal top edge 54 at or near the level of the top of the rotor, and at its inner or left side it is continued upwardly toward the right from a level just above, forming a chute wall 55 in a plane atan angle of between 25 and 30 degrecs to the vertical in the present instance (although this may be varied).. It stops at a line slightly to the right of a vertical line through the axis of the rotor. In the present instance, this planiform part 55 is tangent to the arc of the peripheral wall 52, and the back wall 53 is continued upwardly a similar distance and joined thereto. A parallel corresponding upper front wall 55 is joined to the forward edge of the chute wall 55, the lower edge of this front wall being trimmed horizontally at the same level as the edge 54 in this instance. This wall 55 and the wall 52 therefore form an opening at the front side of the casing, exposing the rotor at its front side. The upper right hand edge of the wall 52 stops at about the level of a horizontal radius of the rotor, and the continuation thereof upwardly is formed by a vertical thicker side shoe plate 52, (to be described) which thus extends at a tangent upwardly completing the casing 5| to the edge 54 which is thus the top edge of the shoe plate. The right han edges of th

walls

53 and 53 are inclined slightly toward the left at an angle of between five and ten degrees, although this may be omitted or varied, as desired. Since the wall 52 stops near a level with the upper side of the rotor, an opening 58 is thus formed extending to the top of the plate 55, through which snow and air may be discharged by the rotor as will be described. Pivoted on the

walls

52 and 56 near their right hand edges, there is a directing or deflecting hood 50 consisting of two sector shaped itudinal axis of the tractor unit, and in fact,

the outer termination of the peripheral wall of the rotor case, at 4, is located well outwardly of the plane or' track of the right hand wheel 20. In consequence, the belts 48 extend diagonally downward from the plow power plant, as may be seen in Figure 1. The left side of the casing 5| is adjacent the medial line of the path of the tractor. The back plate 53 has its right hand edge at the lower part joined to and stopping at the right hand shoe plate 82 of the plow proper, this shoe plate extending downwardly a distance below the lowest part of the wall 52, and having a runner shoe 15 mounted thereon for vertical adjustment as will be described. The shoe plate may extend forwardly at its lower part a distance, its forward edge being inclined backward to the lower edge of the wall 56, which is secured thereto. The forward edge of the side plate 82 may be reinforced by a sharpened removable blade edge 63 as shown, and at its lowermost forward part the plate 62 has fixed thereon a replaceable shoe blade 64 extending forwardly from the plate 82 and formed with a runner edge curved upwardly and forwardly, as shown.

Around the lower front edge portion of the wall 52 next to the side shoe plate 62, a suitable snow guide plate 65 is provided, united with the wall 52 and the plate 62, stopping short at its edge above the lower level of the blade 53. On this plate there are replaceably fixed two

blades

66 and 51, respectively, one extending downwardly and' forwardly from the lower central part of the wall 52, while the other similarly inclined, extends laterally from one 65 to immediately adjacent the forward termination of the side plate 62, the blade 53 extending a distance forwardly thereof. The parts 82 to 51 inclusive constitute a continuation or right end portion of the plow, now to be described.

The plow At the left hand side of the casing wall 52, a laterally extended plow or plow arm is mounted, of the same height as the side shoe plate 62 and comprising a plate 51 curved so that its lower part slopes forwardly and downwardly, while its upper part slopes forwardly and upwardly, its lower edge, however, advanced more than its upper edge. It is extended from the casing 5| laterally and forwardly toward the left at a horizontal angle of about 50 degrees to the fore-and-aft axis of the apparatus, which axis is coincident with the path of the tractor. The curvature of the plate 10' corresponds with that formed by the geometrical projection of the forward edge of the wall 52 in the direction in which this plow arm 10 is extended horizontally. At its lower edge the plow is provided with a plate 62 is spaced beyond the plane and track of the right wheel 20. In a machine constructed in the proportions shown to clear a swath three feet in width, the left side ofthe plow or shoe plate 89 is about three and one-half inches outwardly of the left wheel track, and the right hand side shoe plate 52 is about nine inches outwardly of the right hand wheel track. This side shoe plate likewise has a forwardly pro jected shoe blade H' at its lower ed e formed like the shoe blade 54 before referred to, and is extended backwardly of the shoe blade H sufficiently to afford a mounting for a vertically replaceable blade 68, and its upper edge may a lesser distance outwardly of the plane or track of the left wheel 20 than the right hand shoe adjustable runner shoe '2 similar to the one 15 before referred to at the right hand side.

The plow arm 10 is suitably supported in fixed angular relation to the frame 30, which includes in the present instance, struts 13 extending from the forward part of the frame 30 to a plate 14 fitted and welded to the rear face of the plate 88, and the side shoe plate 69 is braced by a strut I5. Each of the runner shoes 12 and 15 consists of a short runner proper 16, having front and rear ends curved upwardly and a central integral vertical standard 'I'I united therewith, and which may comprise a portion of channel iron, U-shaped in horizontal section with the side flanges presented outwardly toward or against the inner face of the respective side shoe plates. Reinforcing webs H are provided between the ends of the runners and the standards. On the plates 62 and 69there are fixed guide blocks 18 slidably in the channels .of the standards, and a bolt 19 is engaged through each shoe plate and block 18 and through a vertical slot in the standard, a nut being engaged on the bolt to clamp the standard in adjusted positions.

The rotor The rotor 50 in the present instance comprises a planiform circular plate--a diso8l, having a hub 82 fitted to the forward end of the shaft 46, and fixed against rotation thereon in any approved way. The disc 8| has removable blades 83 mounted thereon (four in this instance) and the diameter of the disc is equal to the radius of the blades for a special function which will appear. Each of the blades consists of a sheet metal blank substantially rectangular in shape, the major body portion being planiform, and one edge portion being bent at right angles to provide a foot flange 8,4 apertured to receive bolts by which it is attached removably to the disc 8|, while its opposite edge portion is curved laterally toward the opposite side from the foot flange, forming an advance draft and slicing edge 85. Welded to the back side of the blade near the slicing edge there are two struts 86, which extend to the outer edge of the respective foot flange-of the blade and are welded thereto. The struts are also in the present instance inclined from the ends of the blade slightly so as to clear the space over the foot flange 84 at the ends, while supporting the extreme end corners of the blade, especially the radially'outer corner at the slicing edge. The struts may be otherwise placed or the blade otherwise braced in accordance with 85 as shown has the effect of drawing the snow inward toward the disc when the device is in operation, at the same time that the fiat parts of the blades propel and develop centrifugal force in the mass of snow to throw it outwardly, and the rotor also acts as a fan to draw air inward with the snow-and blow it outward, so that the air serves as a carrying medium for the snow. Welded to the back of each blade there are two fingers 88, projecting horizontally forward therefrom which have been formed of inch steel rod stock. The one near the outer end of the blade has been extended about two and one-half inches forwardly beyond the edge 85 of the blade l3, and the one near the hub of the rotor has been so extended about one inch and a half, although these proportions may be varied as discretion dictates.

The hood, chute, and plow body parts, including the side shoe may be made of sheet aluminum for extreme lightness, and to avoid corrosion, or a rustless steel may be used without the device becoming too heavy for handling by a single person with great ease. The blades of the rotor are preferably of steel suited to the use.

p ration The machine being assembled as described and a tractor such as indicated being available, the plow is coupled by moving the tractor into place behind the plow, removing the shaft 25, and pivot coupling bolts 2i, then adjusting the bracket 21 between the springs 25-31. and reinserting the shaft 35, then securing it by cotter plus. The bolts 26 are then put in place in the bearing 32 and securing them to the plates 25.

The motor of the tractor unit is then started preparatory to moving the machine to the scene of operation, and the motor of the plow lmit may be started at the same time, or it may be started after reaching the place where operation of the rotor is required. It is contemplated to adjust the throttle of the motor of the plow unit so as to operate at a predetermined speed when in advance of the plow proper, packing a certain amount of it downward and aiding in the support of the plow, but more especially intended to sever packed snow near the ground, so that the portion in the path of the advancing plow may be more readily moved to the rotor. It will be seen that in the present embodiment the right hand one-half of the snow in the path to be cleared may move directly into the rotor, while the left half is engaged by the plow I0 and moved by the plow to the right, so that the snow in the right half of the path is crowded toward the right hand side shoe plate by the snow moving convergently thereto along the face of the plow arm 10. This condenses the snow somewhat and enables the rotor to work more effectively on the mass of snow to be moved. In case it is desired that the level of snow in the path cleared be higher-that is, if a deeper layer of snow is desired to be left in the path cleared-the runners 12 and 15 are adjusted downwardly further on their mountings.

As the machine moves forwardly, the rotor turning in a counter-clockwise direction as viewed in front-of the machine, the snow is concentrated in the opening, and the advancing machine brings the slicing edges of the blades of the rotor into engagement with the snow, each one shaving oil! a certain'amount from the face left by the preceding blade. The fingers 88 are valuable in loosening heavy (wet) snow, which tends to become blocked in advance of the blades 23. The sliced-ofl snow is thrown rearwardly toward the rotor disc 50, and also being moved through snow of uniform depth as involved in a particular area to be cleared, and this might be diflerent for diiferent depths of snow 01' quality thereof. If however, the plow motor is equipped with an automatic governor, the latter may be set to maintain a predeter mined proper speed under load which may be the same for various depths. It may, however, be deem d desirable to set the governor for a higher, speed than normal where exceptionally deep and heavy or packed snow is present. .But the load on the plow rotor may be governed by the speed of progression of the tractor unit.

The two motors being in operation, the tractor clutch and gearing are engaged so as to move the assembly forward at the desired speed with the opening 52 presented in the direction in which snow is to be thrown, while the operator manipulates the handles 22 to lower the blades 65-52 to the proper level, where they will be supported by the runner-shoes l2 and I5 and also the runner portions of the blades .N-ll.

' It will be noted that the runners 12-15 are located inwardly on the swath cleared by the machine while the rlmner portions of the blades 64-" engaging snow outside the swath are sufflciently narrow notto lift the plow above the position determined by the adjustment of the runners l2 and 15. The latter will usually run on a thin layer of snow left below the blades 5! and 52, and the runner portions of the blades 'II and El will project into fresh undisturbed snow carried forwardly counter-clockwise by the advancing blade by which it was sliced. The centrifugal force set up in the snow thereby causes it also to pack against the wall 52 upon which it slides until it reaches the tangent portion 55, whereupon it moves outwardly beyond the radius of the blade by which it was impelled, and slides with great velocity against the chute plate 55 until it clears the upper end thereof. At the same time-a body of air entrained and impelled by the blades sweeps the snow along and from the opening 55 at the extreme upper part. When the hood 6| is fully retracted, as in Figure 1, the path of the snow upwardly beyond the machine approximately coincides with the slope of the chute plate 55 for a few feet, and then curving toward the right to a maximum height, the snow dropping and settling upon surfaces at varying distances from the machine. When the hood 6!! is adjusted further toward the right, the snow sliding upwardly along the chute plate 55 is deflected in a less steeply inclined path and falls at a shorter distance fromthe machine.

The fingers ll serve to slice up or break up heavy snow and slush so that such material will not become so packed in front; of the rotor that it cannot move into engagement with the blades as the machine is moved forward. In light, dry snow the fingers are not essential, but do not interfere with the proper movement of such snow into the rotor, or its effective engagement and discharge from the machine as described.

In order that the snow may be most effectively and finely broken up before the rotor, the fingers 88 may be staggered on successive blades, and either additionally or alternatively they may be variously bent in the direction of intersecting radii of the rotor, so as to move in different paths from the paths of following fingers as the rotor turns on its shaft. As shown, the inner finger on one blade is bent outwardly away from the larly, or in any other degree or direction.

On the next blade the inner finger is bent inv wardly toward the rotor center or axis, and the other finger on the same blade may be bent simi- This curving of the fingers serves to detach'portions of packed snow, when encountered, from the mass in advance of the blades, so that they are drawn into the rotor and thrown through the chute as described. Beyond the ends of the finger with the parts properly proportioned,

the snow or slush does not ordinarily become packed sufiiciently to prevent its further movement toward the rotor.

When the hood 60 is adjusted all the way toward the right, its outer part is inclined downwhen desired. In the movement of the snow and air by the rotor, the snow takes a course next the curved outer side of the casing and then follows the chute plate55 and hood portion 60, while the air current produced sweeps along against the underside of this travelling body of snow, affording a support and carrier means therefor, causing it to travel a great distance in proportion to the size and power of the apparatus. This formation of the travelling air support and carrier is due to the formation of the very high opening 58, which is much larger than required solely for the discharge of the snow excavated, even at the highest travelling speed of the tractor. A free exit for the air below and in line with the snow is thereby provided, and in addition, a portion of air in currents at lower levels whereby eddy currents impeding the progress of the major body of air at its under side are minimized.

The machine may be readily steered for gradual turns and slight curves by lateral pressure on the handles 22 while the machine progresses, but for an abrupt turn it is easier to position the machine by elevating the plow, which is accomplished by downward pressure on the handles The depression of the handles 22 will lift the bracket 21 against the upper spring 31, compressing the latter somewhat, and through it lifting the frame 30 and plow elements. This will enable the side shoe plates to be lifted clear of the bed of snow beside the machine, so that it may be turned as required by swinging the plow in the proper direction. When the plow is lowered, if a substantially planiform pavement is involved, the forward part of the plow or blade and runner ll-12 will tend to engage the pavement first while the blades 66-61 and the blade and runner 64-16 are still elevated. As the compression of the spring 31 by the bracket 21 is relieved, however, the pivoted end of the frame 30 at 2526 moves further downward until the rear runner shoe I5 at the right hand side of the machine engages the ground. This support, and the lower spring 36 then being compressed sufficiently, checks further relative movement of the parts. Owing to the balance of the tractor unit on its axle, or the fact that it is heavier at the rear part, it serves to, in part at least, counter balanc the weight of the plow unit power plant. The weight on the forward part of the tractor frame is not sufficient to depress the pivot I! further.

and there is no rocking of the plow unit on the shoe l6 and lifting of the forward part of the plow. However, if the forward runner shoe 1! encounters a rise of surface of the pathway or roadway it is lifted, and the weight of the rear of the plow unit at the pivotal connection with the tractor unit causes the rear part of the plow to drop, moving the tractor unit on its axle so that the bracket 21 is depressed slightly compressing the lower spring 36. When the forward shoe I2 passes over such a rise, relief of support thereof, while the rear shoe l5 rests upon the surface at its higher part causes the forward part of the plow. to fall, elevating the forward part of the tractor unit and pivot 26, the bracket 21 moving slightly upward and compressing the upper spring 31 while relieving the lower one 36. The handles 22 become lowered at thesame time. These movements may be facilitated, if necessary, by

. corresponding manipulations of the handles by moderate pressure or slight lifting movement thereof. While in the present instance the rotor extends from the extreme side of the swath to the middle thereof, the diameter of the rotor may be made still smaller relative to the width of the swath, still keeping it close to one side, and the plow 10 being made relativelylonger. It may be operated from the tractor power plant, if preferred.

The device has been made in various sizes, as indicated, and in one example, suitable for clearing sidewalks, has an overall width of three feet from the plane of the side shoe plate .62 to the plane of the side shoe plate 69, while the plow I0 is approximately fifteen inches in height at its extremity and 22 inches in height at its junction with the casing 6| of the rotor. This particular size of the device is effective in snows ranging in depth from one or two inches to one foot or more. In the latter cases, the weight of fresh fallen snow above the plow 10 causes it to fall toward the device as the latter advances and the snow at the side next the plow falls toward the right and is drawn into the rotor before the plow penetrates materially under the snow. Where snow center fore-and-aft line or axis of the plow unit is a material factor in enabling the ready handling of the device to cut a straight path, for the reason that owing to the function of. the rotor, the latter relieves impedanceof the snow to forward progression of the device at that side, and the snow pressure of the great lateral reach of the plow 10 would tend to be unbalanced and to turn the machine toward the left; whereas, with the tractor located off center in the direction in which the plow 10 projects laterally, this tendency is overcome and the machine tends to move ahead in a straight path. When the diameter of the rotor is made smaller in proportion to the total width of the swath, the location of the tractor unit may be more toward the right. The offset of the plow unit from the axis of the tractor unit is proportionate to the difference between the dialrfigter of the rotor and total width of the plow u The machine may be easily steered while progressingforwardly by appropriate lateral pressure on the handles 22, although an abrupt turn can be more readily made by first elevating the Plow.

The height of the opening 58 from the edge 54 to the outer edge of the hood 88 when the latter is fully retracted has been two feet in a threefoot-swath, and the diameter of the rotor has been made eighteen inches. The disc 8| has been produced in plate steel. and the blades 83 have been produced from inch thick cold rolled steel plate, but may be made from special steels of various kinds, and if made of a rustless alloy will have advantages in'preserving a smooth face at the concave and adjacent fiat surfaces on which snow may slide freely.

While a specific embodiment of the invention has been disclosed, it will be understood that this is purely exemplary, and that various modifications of construction, substitution, and changes of proportions may be made without departing from the spirit of the invention, as more particularly set forth in the appended claims.

The device may be arranged to be attached to other forms of tractors, including four-wheel type, with appropriate modification of coupling,

and may be used for highway clearing and other large scale excavation operations, including wagon or truck loading.

In addition to the turning movement due to differences in resistance-to forward progression of the machine at opposite sides, there is also a resultant of the lateral pressure of material against the plow arm 18, which tends to swing the machine toward the left. This is opposed by the side shoe plate 88 at the end of the arm, and maybe further corrected by an inclination of the side shoe plate 68 laterally inward toward the front, if necessary. I

In order to minimize liability of serious damage, the rotor disc 8| is secured to the shaft 46 by means of a pin 80 of a material adapted to be sheared by the hub 82 and the shaft 48 of the rotor when an excessive strain is imposed thereon.

The disc 8| performs an important function in preventing retardance of the rotor by snow which might become packed or frozen against the back wall of the casing, where such adhesion ismore likely to occur than elsewhere (due to slower movement of snow adjacent the axis of the rotor), and where it is less likely to be cleared, because the pressure of snow thereagainst is less than at the periphery of the case. In the operation of the rotor, therefore, movement of snow rotatively or radially will not be opposed by snow on the back wall of the casing, and snow particles which become attached to the disc 8| are caused thereby to be moved at maximum speed so that the greatest possible centrifugal force is developed therein, by which its movement from the disc will be facilitated under normal operation of the machine.

The disc 8| is shown as formed with a multiplicity of apertures 81 which may be omitted if desired, constituting air inlets, and the back wall of the case may be suitably ported within the zone of the disc to admit air therethrough in case this is found desirable. The effect of the apertures 81 is that air is'drawn from the rear forwardly through the disc all by the vacuous condition produced between the blades of the rotor by the outrush of snow and air therefrom,

- acted, so that the,snow is kept free for movement radially along the blades 83.

The tractor frame andwheels with the runners of the plow unit may be considered broadly a truck, and if desired, wheels may be substituted for the runners and 18, especially where the machine is to be used for other material than and a film of air is formed next the disc by which pressure of the snow thereagainst is countersnow. It may be used as a scraper for dirt surfaces, and for clay scraping where weathered clay surface is to be moved or gathered, as in brick-making. The device may also be found useful in conditioning sea beaches, for taking up surface sand and redistributing it with an untracked surface, and for removing paper and other trash from the sand.

It will be understood that the term fixed in the claims relates only to the position of parts at a given adjustment and does not limit relative adjustment of parts which at other times are relatively fixed. r

We claim:

1. In a machine of the character described wherein there is a two-wheel tractor unit having rearwardly located single axis wheels and a plow unit mounted in front thereof: the structure wherein the plow unit includes a rigid truck frame extended to an intermediate position on the tractor unit, a pivotal connection between 2. In a machine of the character described, a.

plow unit, means to propel the same, a laterally located rotary centrifugal excavator-thrower device thereon having arotor mounted on a foreand-aft axis and open toward the front with the periphery of its rotor at one extreme side of the unit, and a lateral diagonal pusher plow device extended from the opposite side of the excavatorthrower device, its inner end in delivery relation to the excavator-thrower device, said excavatorthrower device having a substantially circular case partly surrounding the rotor, and open at the upper part adjacent the outer side of the excavator-thrower device from a line inwardly of the axis of the rotor closely adjacent the level of the top of the rotor to a vertical plane substantially tangent to the rotor at its outer side, said case having an upstanding chute consisting of a fixed inner chute wall inclined laterally of the unit from the first named line substantially at a tangent to the rotor periphery, and parallel back and front chute walls of thev same height joined to the inclined wall and joined to said case, the space between said front and back walls at the outer side of the unit being open from said first named opening in said case to the extremity of the inclined wall.

3. The structure of claim 2 in which said rotor rotates to move at its upper side in the direction of the outer side of the excavator-thrower device, and is constructed to admit air at its inner part from a direction other than that of incidence of the material delivered thereto to be thrown, whereby a substantially large body of air is projected with the thrown material passing through the chute, as a supporting stratum and carrier.

4. The structure of claim 2 in which a hood is pivoted on the upper part of said chute on an axis substantially spaced below the apex of the chute, said hood having side walls closing the sides thereof adjacent said front and back walls, and a curved transverse wall close to the extremity 0f said'inclined wall, said hood being movable from a position with the outer edge of its curved wall closely. adjacent the inclined chute wall to positions variously extended laterally and downwardly.

5. In a machine of the character described a two wheeled truck tractor unit, a plow unit including a. rigid frame having two rigid side members projecting rearwardly therefrom at respective sides of the tractor unit, a pivot coupling between the tractor unit and extremities of the said side members of the plow, the tractor unit having a part projected a substantial distance forwardly from the pivot coupling, and springs over and under said projected part seated on the plow frame for the purposes described, said projected part being removably engaged between the springs.

LESLIE G. MORSE.

ARTHUR R. HILL,

CHARLES C. MORSE.