US2978720A

US2978720A - Rotary sweeper or broom

Info

Publication number: US2978720A
Application number: US715551A
Authority: US
Inventors: Le Grand H Lull
Original assignee: LULL ENGINEERING CO
Current assignee: LULL ENGINEERING Co
Priority date: 1958-02-17
Filing date: 1958-02-17
Publication date: 1961-04-11
Anticipated expiration: 1978-04-11

Description

April 11, 1961 LE GRAND H. LULL 2,978,720

ROTARY SWEEPER OR BROOM 5 Sheets-Sheet 1 Filed Feb. l?, 1958 INVENTOR e y6mm/ H. L uu- /77' ra RA/Eys April 11, 1961 LE GRAND H. Lum. 2,978,720

ROTARY SWEEPER OR BROOM 5' Sheets-Sheet 2 Filed Feb. 17, 1958 m HHM INVENTOR. eG/mvo lua.

q/z2 Afram/ers April 11, 1961 LE GRAND H. LULL 2,978,720

ROTARY swEEPER oR BRooM 5 Sheets-Sheet 5 Filed Feb. l?, 1958 JffaR/vfys M [Y w Mm wm /1 ffnnlilunnlrnu m i. Y vw MN m f ZZ? April 11, 1951 LE GRAND H. LULL 2,978,720

ROTARY swEEPER 0R BRo'oM- 5 Sheets-Sheet 4 Filed Feb. 17, 1958 O L n TL Ww M 0 N n w .r

Y B .mv 1 iii MX m1 MNNIFHNI April l1, 1961 LE GRAND H. I ULI. 2,978,720

ROTARY swEEPER oa BRooM Filed Feb. 17, 1958 5 Sheets-Sheet 5 INVENTOR. lie/:N0 H. au

A rraRA/E ys eUrtit@ Patented Apt'. il, '1961 non-tar swanrnn on nnooM Le Grand H. Lull, Minneapolis, Minn. Lull Engineering Co., 3045 Highway 13, St. Paul, Minn.)

Filed Feb. 17, 1958, Ser. No. 715,551

12 Claims. (Cl. .l5-82) My invention relates to improvements in what are commonly referred to as street sweepers, used for cleaning, smoothing and conditioning such vehicular surfaces as streets, highways, parking areas and the like. The primary object of my invention is to provide a machine of this kind having a large broom rotatable about a generally horizontal axis and adjustable in horizontal planes, from a transport position in which the broom is centered on the direction of travel of the machine, to various angles with either end ahead of the other so that rotation of the broom will act on the surface material and move it toward either side required. A further important object of the invention is to provide a machine of this kind in which the broom is rotated by a reversible fluid motor so that the direction of rotation of the broom may be readily changed and the machine thus operated with equal effectiveness either in a forward or rearward direction of travel, with the brush rotating in either direction and sweeping done equally well under all conditions encountered. This is a great advantage in crowded situations or where there is much vehicular traffic around and about the area being swept, as will be readily appreciated by those skilled in the art.

Another object of my invention is to provide a ma chine of this kind which is of unitary or self-contained design, by contrast with the more vusual tractor-trailer type of sweeper, and which therefore is more compact, maneuver-able and readily handled in trac. As a related object my machine has a rearwardly located engine, operators station and traction wheel unit connected by an arched lonitudinal beam or boom to a forwardly located steering wheel unit, with the broom supported and operative between these units so that not only does the operator have good vision but the front to rear weight distribution is good and the engine, being at the extreme rear, is out of the dust so that it will require much less repair and service than would otherwise be the case.

A further object is to provide a machine of the foregoing character in which only one engine is necessary for traction purposes and in which all other operations such as raising, lowering and angling the broom and rotating the same are carried out by fluid under pressure with the pumps powered by said engine, there being a separate pump for supplying the iiuid to the reversible motor rotating the broom. The aforesaid arched beam or boom connecting the front and rear wheeled units is tubular and its interior is utilized as the storage reservoir from which the pumps take the fluid for operation of the broom. The boom thus serves two functions and because of its size and length provides an adequate supply of fluid for all purposes, and one which may be readily circulated and cooled to maintain it in best condition for operation of the various components of the machine.

These and other more detailed and specific objects will be disclosed the course of the following specification, reference being had to the accompanying drawings, in .which- Fig. l is a plan view of the machine according to my invention, the broom being shown in full lines at one angled position and in dotted lines in the straight-away transport position.

Fig. 2 is a similar view but showing the broom angled to another position and the machine in condition for operation in a travel direction opposite to that of Fig. 1.

Fig. 3 is a side elevation, the broom being shown as intermediate the positions of Figs. l and 2 and, therefore, in end elevation. p

Fig. 4 is an enlarged cross sectional view, taken substantially along the line 4 4 in Fig. 3, and showing the broom and related components in rear elevation.

Fig. 5 is a longitudinal sectional detail view of the upper and central parts of the machine and associated parts.

Fig. 6 is a schematic View of the hydraulic system for my machine.

Referring now more particularly and by reference characters to the drawing, the rotary broom or sweeper of my invention comprises a wheel borne, self-propelled frame designated generally at A which supports and operates a rotary broom or brush B. Said frame A comprises a rear power and traction unit designated generaliy at it?, a forwardly located steerable wheel unit 11 and a connecting, longitudinally extending and centrally located backbone element in the form of a gooseneck boom `or beam l2.

Units

10 and 11 are spaced some disance apart and the broom 12 is elevated so that space i3 (Fig. 3) is provided for the positioniny and manipulation of the broom B which is quite large and the construction of which will presently be set forth.

The rear power and traction unit 16 comprises a suitable chassis iii on the rear of which is disposed a power plant in the form of an internal combustion engine 15 having a suitable hood enclosure 16, and this engine provides propulsion power for a pair of traction wheels 17 located at the forward end of the chassis 14. Such power is, of course, transmitted from engine to traction wheels through a suitable system of gearing (not shown) to vary the travel speed of the machine, to reverse its direction of travel and otherwise control the action 0f the machine as may be required but since such system is well known to the art the same is not detailed herein. As a matter or" fact and while the unit it! may be completely of special manufacture it is expedient to use a common, commercially available industrial type of tractor for the purpose, with such alterations as necessary, i.e., removal of the front wheels, etc. In any event, this unit 1t) further includes an operators station 18 convenient to the customary clutch and transmission co11- trols (not shown) as well as others to be described herein, and to a steering wheel i9 for controlling the unit 11 as will also be set forth. The steering wheel 19 is carried by a bracket 2d which is atxed to a heavy, transversely extended, elevated and tubular cross yoke 21 which is rigidly supported by heavy side legs 22 angling upwardly and forwardly from the forward end of the aforesaid chassis 14 and rigidly secured thereto. Added strength is provided by braces 23 extending rearwardly and downwardly from the junctions of the legs 22 and yoke Zi and secured, as by brackets 24, to the chassis some distance rearwardly of the traction wheels 1'7.

The boom l2, as it will hereinafter be called, is made of heavy tubing, being securely welded at its rear end at 25 to the cross yoke 21 from whence the boom extends forwardly in a substantially horizontal plane for a considerable distance (Fig. 3) being then curved and angled downwardly at 26 to meet the center of the steering unit il at which point the tubing is welded at 27 to the top plate 28 of a center support 29 forming part of unit 11.

- Y 's .This forward end of the boom is thus closed, liquid tight, .but at its rear end its interior communicates with that of the cross yoke 21 which itself is of heavy tubing and closed, liquid tight, at its opposite ends as designated at 130. Thus the cross yoke and boom form an elongated 'closed chamber of considerable volume for a purpose fpresently to appear. The support 27 is carriedby a truck 31 at the ends of which wheels 32g are mounted by steerl-ing knuckles 33 for steering movements about generally upright axes. The steering knuckles 33 are connected by a tie lrod 34 and the latter may be moved in transverse directions by conventional steering gear in a gear box :35 secured to support 29 and operated by a sectional steering shaft 36 extending upwardly, then rearwardly and hagain upwardly along the length of the boom l2 and fconnected, of course, at its rear end to the aforesaid steering wheel 19. Said steering shaft 36 is journaled at lfsuitable points by bearings 37 upon the upper side of the `lboom 12 and a number of universal joint connections 38 between the shaft sections permit, without binding, rotation by the steering wheel to steer the wheels32 as may be required in maneuvering the machine and controlling f`it as it travels. The wheeled truck 3l. is rockably mountfed to the support 29 for oscillation in a transverse upright Aplane as indicated at 39 (Fig. 3)-so that the wheels 32. --may accommodate themselves to transverse angularity of Athe surface over which the machine travels as will be iunderstood.

Turning now to the 'construction of the broom or "sweeper unit B the same comprises a cylindrical brush 40 made up of a multiplicity of radially directed, fibrous bristles 41 suitably secured to a core 42 on a shaft 43 Cjournaled in bearings 44 carried at the forward ends of 'a heavy U-shaped frame 45. Said frame 45 includes "heavy channel or angle ends which are welded to a heavy cross tube 46 and supported by this frame also is a sub- 'stantially semi-circular hood or shield 47 which encloses inthe upper, rear portion of the brush. This assembly is ycarried by a pair of transversely but relatively closely l'spaced heavy hangers 48 fabricated for purposes of Mstrength from tubing, and having at their lower ends 'heavy hinge lugs 49 apertured to pivotally engage a 'transverse rock shaft 50, located rearwardly of and below the center of the cross tube 46. A bearing sleeve 51 on f said rock shaft 50 between the lugs 49 is connected by a heavy pivot shaft 52 to a bracket 53 extending forwardly lto and secured in a rearwardly projecting position upon said cross tube 46. From these lower points of pivot attachment to the broom assembly the hangers 48 angle -lpwardly and then forwardly, well above the hood 47, and at their upper forward ends, above the brooms axis Iof rotation, the hangers are secured to the lower bearing :plate 54 of a fth wheel'type of broom bearing mount, the mating upper bearing plate 55 of which is welded and rigidly braced to the underside of the boom 12. These cooperating bearing plates 54--55 are located in la horizontal plane for relative movement about an up- `right pivot axis, defined by a heavy king bolt 56 (Fig. 5) which connects the plates and suspends the broom B when the same is elevated to its transport position. The bearing surfaces between the plates Sti-55 are large in area to provide the necessary support against the stresses `to which the broom is subject, while permitting the broom to be swung about its vertical pivot axis even while it is in working contact with the surface being swept.

Referring to Fig. 4 particularly it will be seen that l provide a pair of double acting angularly related rams or reciprocating fluid motors 57-58, one located at each side of the hangers 48, and the cylinders of these rams are pivoted at lower ends at 59 to brackets 60 affixed to the cross tube 46 at relatively wide spread locations. From these points the rams `57---58 `converge in an upward direction and at their upper ends have axially movable, uid actuated piston rods 61 which are pivoted at agravan 62 to brackets 63 welded to the hangers 48. The rams 57-58 thus also support the broom from the hangers 48 but in addition act as elevating and tilting means for the broom. Due to their angular, downwardly diverging relationship the rams provide good lateral support and stabilization for the broom, and if fluid is admitted to the lower ends of the ramcylinders in equal amounts they will lower the broom to its work without changing its aspect to the ground surface, whereas equal uid supply to the upper ends of the rams will elevate the broom to transport position. However,'admission of uid to either ram alone, or to both but in differing amounts will tilt the broom in a generally transverse upright plane about the axis of the shaft 52 and thus accommodate the broom to the angularity of the surface over which it is traveling.

As will best be seen in Fig. 3 the aforesaid raising and lowering of the broom is an arcuate one about the relatively rearwardly located axis of the rock shaft 50 and the rams 57-58 and their connections between the hangers i5 and cross tube 46 are located in planes well forward of said rock shaft so as to exert the necessary leverage upon the broom. The hangers 48 have a heavy cross brace 64 joining them some distance above their lower, rear ends and in addition they are connected by a shield or cover 65 protecting the upper pivots 62 of the rams v5"7--58.

The broom B is angled about the upright axis of the bearing afforded by the bearing plates 54-55 by an elongated double action control ram 66 which extends generally parallel to the rear portion of the boom 12 and has a cylinder pivoted on a vertical axis at 67 to bracket ears 68 aixed to the cross yoke 21 adjacent one end thereof. From this point the ram 66 extends forwardly and its axially slidable piston rod 69 is pivoted on a vertical axis at 7i) to the end of a radially extending lever arm 7i forming part of or secured to the lower bearing plate 5d. Note Figs. l and 2. It will thus be seen that the admission of fluid to the rear eno' of the ram 66 will project the piston rod 6% forwardly and through the lever arm '71 will turn the bearing plate 54 and thus the entire broom assembly B in a clockwise direction as viewed from above in Figs. 1 and 2 whereas admission of uid to the forward end of the ram will retract the piston rod and swing the broom in the opposite direction. -T he travel movement permitted the piston rod 69 and location of the lever arm '71 are such that -the broom B may be moved from the transport position shown in dotted lines B in Fig. l at which the broom 'is longitudinally positioned with its axis parallel to the center line of the machine, through an angle of about one hundred and thirty-five degrees, in which the broom is located in the two working positions seen in Figs. l and 2 each at about a forty-five degree angle to the direction of travel. In the transport position seen in the dotted lines B' the broom lies wholly within the lateral limits of the machine so that it will not constitute a traliic hazard in high speed travel from one job location to another.

The brush 4t) is rotated by a conventional reversible, rotary iiuid motor 72 mounted at one end of the hood 47 and suitably braced at 73 to the adjacent end of the cross tube 46. The output shaft 74 of this motor is connected by a sprocket chain mechanism 75 to a sprocket 76 which rotates the aforesaid core 42 and thus the brush itself. Said sprocket chain mechanism and its component sprockets, etc., are suitably housed in guards 77 for safetys sake.

ln operation the machine may be driven by the engine 15 and steered by the steering wheel actuating the wheels 32 in the manner of any self-propelled vehicle and it is contemplated that it may run either forwardly. i.e., in the direction of the Wheels 32 or rearwardly with equal facility. In moving along thoroughfares or from job to job the broom B will be elevated by the rams 5758 about the axis of the rock shaft 50 so that the brush -bristles clean the supporting surface or roadway and will also be swung around to the fore and aft transport position B seen in Fig. 1 so that the machine will occupy the least possible space while traveling. At work the broom B may be actuated by the ram 66 to swing to the position seen in full lines in Fig. rl and with the brush rotating under influence of the uid motor 72 the machine may move forwardly and, as an example, brush and clear off material and windrow it toward the left, as indicated by the line of discharge L in Fig. l. If it is then desired to return over the same path for further treatment of the surface the direction of travel of the machine is reversed (compare the travel direction arrows in Figs. l and 2), the angle of the broom B is reversed and its direction of rotation reversed, and it will then windrow material toward the same line L of deposit as seen in Fig. 2. This is accomplished without either dead heading or going through the awkward maneuvers of turning the machine around at the end of each pass over the surface, a thing which is frequently difcult due to narrow streets, traffic congestion and like conditions. In fact the machine will opcrate with equal facility, whether traveling rearwardly or forwardly, with the broom Bat any angle, and rotating at either of its directions of rotation, and it is accordingly so versatile that it will work faster, under extremely cramped or adverse conditions, than any other apparatus for the same purpose. The use of the two rams 57-58 permits not only height adjustment of the broom but angular adjustments to accommodate it to transverse inclinations of the surface being worked and all adjustments may be carried out with the broom in operation with no need to halt and then go ahead. The rock shaft 50 and pivot 52 form in effect a universal joint connection between the broom and its hangers dit.`

The versatility of the broom as to angle and direction of rotation is in fact such that the broom may sweep with the wind regardless of the direction of travel and this in conjunction with the operators clear view of the operation at all times is conducive to fast and good work. The location of the engine 15 at the extreme rear of the machine protects it from the dust, with a resulting saving in repair and maintenance costs and at the same time the rearwardly overhanging weight of the engine behind the traction wheels provides the best conditions for adequate traction and best possible longitudinal load distribution for the machine as a whole.

The hydraulic system of my machine will now be described, with particular reference to Figs. 5 and 6. Fluid under pressure for operation of the rams 7, 5S and 66 is supplied by means of a conventional pump 78, while fluid for operation of the reversible broom drive motor 72 is provided by a separate pump 79, and these pumps may be conveniently mounted upon a gear case 80 on the forepart of the chassis 14 and powered by means of the gears designated at e1 from the power take-off shaft 82 with which tractors such as used for the unit A are conventionally provided. The interior of the boom 12 and communicating cross yoke 21 serves as a reservoir for the fluid and at a relatively central location along the length of the boom 12 a sump 83 is provided upon its underside and connected by a common intake line 84 to both pumps 78-79- The pressure side of the pump 78 is then connected by a line 85 to a main control valve bank and this line may be selectively connccted by actuation of this valve bank to the upper or lower ends of the ram 57 by means of lines S7 and 88, to the upper or lower ends of the ram 58 by lines 89 and 90, and to the front and rear ends of the rams 66 by means of

lines

91 and 92. A return line 93 leads from the valve bank S6 to a return connection 94 in the underside of the cross yoke 21 and this connection directs the returning fluid into an elongated exible tube 95 extending forwardly through the boom 12, almost to its forward extremity, in such fashion that the duid returning from the various rams to the reservoir; before use again in the rams, is recirculated through a substantial length of the boom as will be readily ap'- preciated. This lengthy recirculation path of the uid provides for the cooling thereof to maintain it in most effective operating condition, as does also the fact that the boom 12 and associated cross yoke 21 have relatively large areas in contact with the ambient air for maximum heat transfer. In addition, of course, the length and size of the boom 12 plus the volume of the cross yoke 21 provides storage for the quite substantial volume of fluid necessary for the operation of the entire hydraulic system.

The pressure side of the pump 79 is connected by a line 96 to a broom control valve 97 having a pair of

output lines

98 and 99 connected to the motor 72 which vrotates the brush 40. A return line 100 leads from this motor to a separate point 101 of re-entry into the interior of boom 12 and the valve 97 by the simple manipula# tion of the control handle 102 will supply tluid through either

line

98 or 99 to rotate the fluid motor 72 in either of its two directions of rotation.

rfhe valve bank 86 includes a series of three valves, two of which are operated by

control levers

103 and 104 for controlling the supply of fluid to the rams 57-58 and these levers are provided with transversely extending, juxtaposed handles 10S so that they may be readily ma-k nipulated by one hand and both valves moved the same amount or in differing amounts as required for tilting, raising and lowering the broom B. The valve controlling the ram 65 is then provided with a separate operating lever 106 conveniently located for operation by the same hand but not necessarily at the same time as the valves controlling rams 57-58 are manipulated. In practice I iind this to be the most desirable arrangement for the valves and the various control handles are conveniently located just to the rear of the cross yoke 21 at opposite sides of the steering wheel 19, as is seen in Figs. l, 2 and 3. I do not, however, of course limit myself to this precise mechanical arrangement of these components of the hydraulic system and since all of the connecting liuid lines have been designated schematically in Fig. 6 they are not traced out nor correspondingly designated in the remaining views of the drawings, it being sucient to note that wherever necessary these lines embody tlexible hoses or conduits which will permit the necessary movements of the broom about its various pivots, as is clearly shown. y j

As designated at 107 a suitable filler plug is provided in the cross yoke 21 so that the reservoir fluid may be replenished when needed.

It is understood that suitable modications may be made in the structure as disclosed, provided such modi? cations come within the spirit and scope of the appended claims. Having now therefore fully illustrated and de scribed my invention, what I claim to be new and desire to protect by Letters Patent is:

, l. In a sweeper of the character described, a wheel borne and self-propelled frame having spaced apart front and rear wheeled units and inclu-ding an engine koperative to provide propulsion power for the frame, an elongated elevated boom element connecting said units, a broom located between the units and below the boom element, a bearing mechanism including upper and lower bearing plates connecting the broom to the boom element for swinging movements of said broom about an upright axis and in a generally horizontal plane from a transport position with the broom in line with the direction of travel and directly beneath said boom element to either of two oppositely angled working positions, means connected from said frame to the lowermost bearing plate for adjusting the angle of the broom, hangers depending from the lowermost bearing plate and including a rock shaft supporting the broom for up and down movements '7 ,with respect to said boom element, means connected from the hangers to the broom for raising and lowering the broom about said rock shaft, said broom including a rotatable brush, and means for rotating the brush in either of two opposite directions of rotation and in any angularly adjusted position thereof.

2. In a sweeper of the character described, a wheel borne and self-propelled frame having spaced apart front and rear units and including an engine operative to providepropulsion power for the frame, anelongated boom element connecting said units, a broom located between the units and below the boom element,` a bearing mechanism including upper and lower bearing plates connectingthe broom to the boom elementfor swinging movements of said broom about an upright axis and in a generally horizontal plane from a transport position with the broom in line with the direction of travel directly beneath said boom element to either of two oppositely angled working positions, means connected from said frame to the lowermost bearing plate for adjusting the angle of the broom, hangers depending from the lowermost bearing plate and including a rock shaft supporting the broom for up and down movements with respect to said boom element, bracket means connecting the broom and said rock shaft and having a pivot about which the broom may be tilted to raise and lower its opposite ends, means connected from the hangers to the broom for raising, lowering and tilting the broom about said rock shaft and pivot, said broom including a rotatable brush, and means for rotating the brush.

3. In a sweeper of the character described, a wheel borne and self-propelled frame having spaced apart front and rear units and including an engine operative to pro- Vide propulsion power for the frame, an elongated boom element connecting said units, a broom located between the units and below the boom element, a bearing mechanism including upper and lower bearing plates connecting the broom to the boom element for swinging movements of said broom about an upright axis and in a generally horizontal plane, means connected from said frame to the lowermost bearing plate for adjusting the angle of the broom, hangers depending from the lowermost bearing plate andincluding a rock shaft and bracket means supporting the broom on said shaft for up and down movements with respect to said boom element, means forming a pivot for tilting the broom and raising and lowering its ends relative to each other, angularly positioned fluid actuated rams located at opposite sides of said pivot and connected from the hangers to the broom for raising, lowering and tilting the broom about said rock shaft and pivot, said broom including a rotatable brush, and means for rotating the brush.

4. In `a sweeper of the character described, a wheel borne and self-propelled frame including an elongated and elevated boom element, a broom located below the boom element, a bearing mechanism including upper and lower bearing plates connecting the broom to the boom element for swinging movements of said broom about an upright axis and in a generally horizontal plane, means .connected from said frame to the lowermost bearing plate for adjusting the` angle of the broom, hangers depending from the lowermost bearing plate and including means forming a universal joint connection between the hangers and broom and supporting the broom for up yand down as well as tilting movements with respect to said boom element, angularly positioned hydraulic rams connected from the hangers to the broom for raising, lowering and tilting the broom, said broom including a rotatable brush, and means for rotating the brush.

A 5. In a sweeper for vehicle supporting surfaces, a wheel borne andl self-propelledframe having a rear unit vincluding traction wheels and an engine operative to .transmit propulsion power to said wheels, a forward mitVhavingnsteerable wheels, an elongated gooseneck boom element connecting said units, an operators station on said rear unit including a steering wheel and means operatively connecting the same to the wheels of the front unit, a broom located between the units and below the boom element, a bearing including upper and lower bearing plates connecting the broom to the boom element for swinging movements about an.upright axis and in a generally horizontal plane from a transport position with the broom in line with the direction of travel and centered beneath said boom element to either of two oppositely angled working positions, means connected from said frame to the lowermos't bearing plate for adiusting the angle of the broom, hangers depending from the lowermost bearing plate and including a rock shaft supporting the broom for up and down movements with respect to said boom element, a bracket connecting the broom and said rock shaft and including a pivot supporting the broom for tilting movements in a generally transverse plane, means connected to the hangers for raising, lowering and tilting the broom, said broom including a rotatable brush, and means for rotating the brush in either of two opposite directions of rotation.

6. In a sweeper of the character described, a wheel borne and self-propelled frame having a rear unit including traction wheels and an engine operative to transmit propulsion power to said wheels, a forward unit having steerable wheels, an elongated gooseneck boom element connecting said units, an operators station on said rear unit including a steering wheel and means operatively connecting the same to the wheels of the front unit, a broom located between the units and below the boom element, a bearing mechanism including upper and lower horizontal and pivotally connected bearing plates connecting the broom to the boom element for swinging lmovements of the broom about an upright axis and in a generally horizontal plane, hangers depending from the lowermost bearing plate for adjusting the angle of the broom, and a rock shaft supporting the broom on the lower ends of the hangers for up and down movements with respect to said boom element, a bracket connecting the broom and said rock shaft and including a pivot supporting the broom for tilting movements in a piane at right angles with respect to said rock shaft, means for swinging and means for tilting, raising and lowering the broom, and said broom including a rotatable brush.

7. In a sweeper of the character described, a frame having a rear unit including traction wheels and an engine operative to transmit propulsion power to said wheels, a forward unit having steerable wheels, an elongated longitudinally ,and centrally extending gooseneck boom element connecting said units, an operators station on said rear unit including a steering wheel and means operatively connecting the same to the steerable wheels of the front unit, a broom located between the units and below the boom element, a bearing mechanism including upper and lower bearing plates connecting the broom to the boom element for swinging movements about an upright axis and in a generally horizontal plane from a transport position with the broom in line with the direction of travel and centered longitudinally below the boom element to either of two oppositely angled working positions, means connected to the lowermost bearing plate for adjusting the angle of the broom. hangers depending from the lowermost bearing plate and including a rock shaft supporting the broom for up and down movements with respect to said boom element, a bracket connecting the broom rand said rock shaft and including a pivot supporting the broom for opposite up and down tilting movements at its ends, means connected to the hangers for raising, lowering and tilting the broom, said broom including a rotatable brush, and means for rotating the brush in either of Vtwo opposite directions of rotation `and in any angularly Aadjusted position thereof.

8. In a sweeper of the character described, a frame having a rear unit including traction wheels and an engine located at the rear thereof and operative to transmit propulsion power to said wheels, `a forward unit spaced from said rear unit and having steerable wheels, an elongated longitudinal gooseneck boom element connecting said units, means for steering the wheels of the front unit, a broom positioned between the units and below the boom element, a bearing mechanism including upper and lower beating plates having cooperating bearing surfaces of large areas and connecting the broom to the boom element for swinging movements of the broom about an upright axis and in a generally horizontal plane from a longitudinal transport position to either of two oppositely angled working positions as much as forty-ve degrees to the direction of travel of the sweeper, means connected to the lowermost bearing plate for rotating the same and thereby adjusting the angle of the broom, hangers depending from the lowermost bearing plate and including la rock shaft and a rearwardly extending bracket on said broom supporting the broom on the rock shaft for up and down movements with respect to said boom element, a pivot pin supporting the bracket from the rock shaft for tilting movements of the broom at its opposite ends, means connected to the hangers for raising, lowering and tilting the broom, said broom including a rotatable brush, and means for rotating the brush.

9. A sweeper for vehicle supporting surfaces, comprising in combination, a wheel borne and self-propelled frame having a rear unit including traction wheels and an engine for transmitting propulsion power to said wheels, said unit also including an elevated tubular cross yoke closed at its ends, a forward unit having steerable wheels, an elongated tubular gooseneck boom element connected to and communicating at its rear end with said cross yoke and having a closed forward end connected to said forward unit, a broom located between the units and below the boom element, means supporting the broom on the boom element for swinging movements in a generally horizontal plane from a transport position to either of two oppositcly angled working positions and also for up and down movements with respect to said boom element, a hydraulic ram operatiVely arranged for adjusting the angle of the broom, a pair of hydraulic rams for raising and lowering the broom, said broom including a rotatable brush, a reversible hydraulic motor operatively connected to rotating the brush in either of two opposite directions of rotation and in any angularly adjusted position thereof, and a Huid supply system for the rams and motor and using as a storage reservoir the interior of said cross yoke and the boom element, said supply system including valves and at least one of said valves having a lluid return connection to the interior of the boom adjacent one end thereof, and a flexible tube leading from said uid return connection substantially the full length of and to a point adjacent the other end of said boom.

10. A sweeper for vehicle supporting surfaces, comprising in combination, a wheel borne and self-propelled frame having front and rear units and an elongated tubular gooseneck boom element closed at its ends and operatively connecting said units, a broom located between the units and below the boom element, means supporting the broom on the boom element for swinging movements in a generally horizontal plane from a transport position to either of two oppositely angled working positions and also for up and down movements with respect to said boom element, a hydraulic ram operatively arranged for adjusting the angle of the broom, a pair of hydraulic rams for raising and lowering the broom, said broom including a rotatable brush, a reversible hydraulic motor operatively connected for rotating the brush in either of two opposite directions of rotation and in any angularly adjusted position thereof, a fluid supply system for the rams and motor including a iiuid supply within said boom element and a series of valves, a iiuid return from a part of said valves to the interior of the boom element adjacent one end thereof, and a tube connected to said iiuid return and extending within said boom element to a point adjacent the opposite end thereof, whereby the fluid must pass substantially the full length of said boom element before reaching said fluid return.'

11. In a sweeper of the character described, a Wheel borne and self-propelled frame including an elongated and elevated boom element, a broom located below the boom element, a bearing mechanism including upper and lower bearing plates connecting the broom to the boom element for swinging movements of said broom about an upright axis and in a generally horizontal plane, means connected from said frame to the lowermost bearing plate for adjusting the angle of the broom, hangers depending from the lowermost bearing plate and including means forming a universal joint connection between the hangers and broom and supporting the broom for up and down as well as tilting movements with respect to said boom element, angularly positioned hydraulic rams connected from the hangers to the broom for raising, lowering and tilting the broom, said broom including a rotatable brush, and means for rotating the brush, the said universal joint connection between the hangers and the broom being located substantially' midway between the ends of the latter.

12. ln a sweeper of the character described, a Wheel borne and self-propelled frame having spaced apart front and rear units and including an engine operative to provide propulsion power for the frame, an elongated boom element connecting said units, a broom located between the units and below the boom element, a bearing mechanism including upper and lower bearing plates connecting the broom to the boom element for swinging movements of said broom about an upright axis and in a generally horizontal plane, means connected from said frame to the lowermost bearing plate for adjusting the angle of the broom, hangers depending from the lowermost bearing plate and including a rock shaft and bracket means supporting the broom on said shaft for up and down movements with respect to said boom element, means forming a pivot for tilting the broom and raising and lowering its ends relative to each other, angularly positioned fluid actuated rams located at opposite sides of said pivot and connected from the hangers to the broom for raising, lowering and tilting the broom about said rock shaft and pivot, said broom including a rotatable brush, and means for rotating the brush, the said rams being located in relatively downwardly diverging positions.

References Cited in the le of this patent UNITED STATES PATENTS