US2406826A - Scraper - Google Patents

Description

Sept. 3-, 1946.

H c. FRENCH ETAL S CRAPER Filed Sept. 28, 1944 3 Sheets-Sheet 1 Sept. 3, 1946. H. c. FRENCH ETAL 2,406,826

SCRAPER Filed Sept. 28, 1944 5 Sheets-Sheet 2 INVENTORJ a 9 BY 77 V mm a Sept. 3, 1946- H. c. FRENCH ETAL SCRAPER Filed se t 28, 1944 5 Sheets-Sheet 3 Patented Sept. 3, 1946 SCRAPER.

Henry C. French, Elm Grove, and Norman V. ,Kuehlman, Milwaukee, Wis., assignors to The Heil Co., Milwaukee, Wis., a corporation of Wis- Application September 28, 1944, Serial No. 556,113

14 Claims. 1 This invention relates to improvements in scrapers.

A general object of the invention is to provide a. highly efficient, relatively inexpensive and practical scraper arranged for front loading and dumping, and wherein the scraper mechanism is operated by a simple andpositive mechanism, the scraper being operatively associated with a standard crawler tractor to which a portion of the scraper operating mechanism may be extended.

A. further object of the invention is to provide 7 a simple, mechanically operated scraper, susceptible of being readily serviced by the average mechanic, and having an unrestricted open top permitting loading when desired, with a power shovel.

A further object of the invention is to provide a scraper which is underslung in character with a high front frame, being particularly adapted for use in connection with high speed, rubber tired tractors.

A further object of .the invention is to provide a scraper having a novel mechanism for transmitting motion from an operating member to the. controllable members of the scraper which includes an independently rotatable cross shaft to which motion is transmitted by a swinging arm, said rotatable cross shaft causing the front apron and bowl bottom to move in proper sequence for bowl loading and unloading.

A further object of the invention is to provide a scraper wherein the movable elements, includingthe apron and bowl bottom, return to their normal positions through the action of gravity,

thereby eliminating the necessity for spring or latch means to hold said parts in their down positions.

A further object of the invention is to provide a scraper having a simple, novel and effective mechanism for operating the bowl bottom or floor and the apron, said mechanism being adapted for actuation either by a cable, or by a. hydraulic jack.

A further object of the invention is to provide a scraper having a tiltable bowl floor and a swingable front apron, the arrangement being such that a common mechanism is utilized for operation of both, but that the sequence of operation of said floor and; apron is such that. the apron may have: imparted thereto: a limited movement Without any movement being imparted to the bowlfloor.

A furtherobject. of the. invention is to provide a. scraper which is. strong; and; durable, is easy to control and service, and is well adapted for the purposes described.

With the above and other objects in view, the invention consists of the improved scraper, and its parts and combinations as set forth in the claims, and all equivalents thereof.

In the accompanying drawings in which the same reference characters indicate the same parts in all of the views:

Fig. 1 is a longitudinal vertical sectional view through one form of the scraper, wherein the operating mechanism is cable actuated, showing the parts in digging or scraping position;

Fig, 2 is a similar longitudinal vertical sectional view through the same form of scraper, showing the parts in dumping or unloading position;

Fig. 3 is a plan view of said scraper in the condition shown in Fig. 2, with parts broken away and in section;

Fig. 4 is a longitudinal vertical sectional view through another form of scraper wherein the operating mechanism is hydraulically actuated, the parts being in digging or scraping position; and

Fig. 5 is a schematic view of the hydraulic jacks, controls, and fluidsystem for the latter form of scraper.

The scraper of the present invention is exemplified as one wherein the forward end of the scraper is adapted to be supported directly by a tractor. By this arrangement, the substantial crawler mechanism of the tractor is brought into action to support a large portion of the weight ofthe scraper and its load. The scraper, as thus arranged, is relatively inexpensive, and possesses great maneuverability.

Referring now more particularly to the form of the invention shown in Figs. 1, 2 and 3 of the drawings, the improved cable-operated scraper shown therein by way of illustration, comprises a sturdy open front frame ill of U-formation. A connecting arm II is rigidly connected to the front transverse member of said frame I0, intermediate its sides, and the same projects forwardly and is downwardly curved to permit its being universally movably engaged with the draw bar of a crawler tractor (not shown). As is conventional, the tractor has mounted on its rear portion, a power control unit, and the drums thereof are adapted to have wound and unwound thereon operating and control cables l2 and [3 whose arrangement will be described more fully hereinafter;

Associated with the front frame It and extending rearwardly thereof is a bowl frame I4 which includes transverse box sections I5 and I6 and a rear axle H, the bowl frame being pivotal on the rear axle, and the rear axle carrying wheels I8. Bearing arms I9 extend rearwardly from the bowl frame box section I5 and have journalled therein a transverse shaft 20. The rear ends of the upper longitudinal members of the front frame II] have welded thereto extension arms 2| engaging bearings on the outer ends of the cros shaft 20. It will thus be evident that the front of the scraper is supported by a tractor, the rear of the scraper is supported by the wheels I 8 and the scraper frames II] and I4 are so articulated that they may jack-knife relative to each other.

Within the bowl frame I4 a dirt-carrying bowl is defined by separated, rigidly mounted side plates 22, a rear wall 23 (whose peculiar construction will be explained more fully), and a movable bowl floor 24. Hingedly connected to the lower edge of the floor 24 is a transverse cutting blade 25, the blade being rigidly associated with the bowl frame. The upper or inner edge of the bowl floor 24 has hingedly connected thereto a closure plate 25 which cooperates with the rear wall in a manner to be hereinafter explained. In the hinged connection for said plate 26 is a stop to prevent undesired forward movement of said plate beyond a limit.

As will appear from Fig. 3, the rear portion of the bowl frame I4 is of less breadth than the bowl forwardly thereof. Extended transversely across the lower intermediate portion of the rear of the bowl frame is a beam 27 which supports an open housing 28. There is longitudinally movably associated with said housing a push column 29 carrying at its rear end a transverse shaft 35 on the opposite ends of which pairs of sheaves 3I-32 and 33-34 are revolubly mounted. Forwardly of the column-carried sheaves 3I32 and 33-34 are pairs of revoluble sheaves 35-36 and 3I38, the pairs being on opposite sides of the push column, alined with the rearwardly disposed pairs of sheaves, and mounted in the housing 28.

A pair 'of complementary spaced apart arms are indicated by the numerals 39. The upper ends of said arms are mounted fast on intermediate portions of the revoluble cross shaft 20. The forward end portion of the push column 29 extends between intermediate portions of the arms 39, and is pivotally connected thereto by a cross-connecting pin 45. The forward or outer ends of the arms 39 are connected by a shaft or pin 4| on which is j ournalled a roller 42.

Between the lower forward edge portions of the side plates of the rear reduced portion of the bowl frame I4 is an opening through which the arms 39 are adapted to be swung. When it is desired to raise the bowl floor 24, the push column 29 is projected forwardly, by means later-to be described, and this causes a clockwise swinging movement (relative to the drawings) of the arms 39 fast on the shaft 29, turning said shaft. The arms are thereupon swun through the front opening of the reduced portion of the bowl frame and the arm-carried roller 42 then contacts a track 43 on a rear surface portion of the bowl floor 24. Continued movement of said arms in the direction described is effective to hingedly move the floor toward a vertical position, as in Fig. 2, for load dumping purposes, the floor hinging relative to the rigidly mounted cutting blade 25. Depending from the lower edge of the upper plate 23 of the rear wall is a hingedly mounted flapper plate 44 which is lifted to the position of Fig. 2 to permit the necessary amount of movement of the arms 39.

When the push column i moved rearwardly. it will carry with it in a reverse direction said floor-lifting arms 39, the same withdrawing through the front opening in the reduced portion of the bowl frame and gravity permits the bowl floor 24 to return to its lowered position, as in Fig. 1, wherein its inner end portion rests on the transverse box section member I 5 and extends thereabove. The recession of the arms 39 permits the hinged rear wall flapper plate 44 to drop to a closing position, as in Fig. 1, and the hinged plate carried by the inner or upper end of the floor 24 overlaps the depending plate 44,

as in Fig. 1, and cooperates therewith and with the fixed plate 23 thereabove in providing a complete closed rear wall for the bowl when the parts are in digging or load-carrying positions.

The scraper assembly also includes a load-confining front apron 45 having integral opposite side arms 46 disposed between and swingably suspended from the side walls 22 of the bowl by means of alined pivot pins 41. The apron has its lower transverse cutoff edge 48 cooperable with and swingable adjacent the cutting blade 25 of the bowl floor whereby material may be confined within the space bounded by the bowl side walls 22, the bowl floor 24 and the bowl rear.

There are mounted fast on outer end portions of the shaft 20 so as to turn therewith projecting levers 49. Clevises 50 are pivotally attached to the outer ends of these levers and the rear ends of flexible connections 5! are afiixed to said clevises. The forward ends of the flexible connections 5| carry clevises 52, which are pivotally attached to intermediate portions of the side arms 46 of the apron 45.

The sheave and cable lacing arrangement for the scraper will now be described. The cable I3 is for the purpose of raising and lowering the entire bowl assembly. As was previously mentioned, said cable extends forwardly to a winch drum mounted on a tractor to which the scraper is coupled. From the winch drum, said cable I3 is extended rearwardly, engages under a vertical sheave 53 mounted on one side of the lower portion of the front frame connecting arm I I. From the sheave 53, said cable I3 then passes over an upper sheave 54, also carried by the front frame connecting arm, and then the cable extends rearwardly and about a sheave 55, which is revolubly carried by a bracket 56 extending upwardly from a transverse front upper'box frame section 51 integral with the front frame I0. Said bracket 56 also has revolubly mounted thereon alined upper sheaves 58, 59, 60 and BI. Mounted on a forward upper transverse box frame member 62 of the bowl frame is a bracket 63 which also carries on a horizontal axis, a series of lower alined sheaves 64, said lower heaves corresponding in number to the upper sheaves to SI, inclusive. From the upper sheave 55, which is engaged by the cable I3, the cable is first passed downwardly about one of the lower sheaves 64, and then it extends alternately upwardly and downwardly, passing about all of the upper and lower sheaves previously specified. The result of this arrangement is that when a forward pull is imposed on the cable I3, a scissors or jackknifing action will be imparted as between the front frame I0 and the bowl frame, the latter pivoting on the wheel axle I1. Fig. 1 represents acoaeao causes the lower sheaves 64 to be drawn toward the upper front frame-carried sheaves 55-451..

While. the cable I3: is for the purpose of raising and lowering the entire. bowl, assembly, the cable I2 i for the purpose. of controlling, in proper sequence, the. movements of the front apron 4.5 and the bowl: floor 2.4. Said cable, 12, extending rearwardly from the winch. drum, extends. under a vertical sheave 65. on the, front frame arm I I and then passes upwardly and over an arm carried sheave 6 6. A horizontal sheave 61 on thefront transverse member of the front frame then engages; the .cable and directs. it latorally to. a sheave E8; borne by a forward side portion of the front frame. A. sheave 69 at the rear of the front frame, on the same side as the sheave 68. then. engages the cable and directs it diagonallyrearwardly inwardly to a vertical, angularly directed sheave 10 mounted on the housing 28. The sheave 10 directs the cable to the sheave 35 whichin turn guides it rearwardly to sheave 3i. After extending about the latter sheave the cable then passes forwardly and about sheave 36 and then rearwardly to sheave 32. From the latter heave the cable then extends about an intermediate, housing-carried sheave 1| from whence .it passes to the sheaves on the other side of the push column 29 including in the order named, sheaves 33, 31, 34 and 38. The cable is dead-ended after engaging the lastmentioned sheave.

If it be assumed that the parts are first in the digging or loading position. of Fig. 1, from the description of the cable arrangement given it should be obvious that a pull on the. cable is. ef-. fective to exert an end thrust on the rear end of the push. column 2-9. which carries the cableengaged sheaves iii-32 and 33-34,. This end thrust forces the push column forwardly also swinging forwardly the arm 39 which are pivotally connected'to the push column. As the upp r en of said arms are mounted fast on the revoluble cross shaft 20 said cross shaft will be turned in a clockwise direction (referring to. the drawings) and the levers 49 will. be swung rearwardly. This action will impose a rearward pull on the flexible connections to elevatethe apron i5. ultimately to .the full open, unloading position of Fig. 2.

The arrangement of movable parts and se quence of operation is such that the initial pull on the cable 12 will first cause the front apron 45 to be elevated at desired distance and this initial relatively short upward movement of the apron is relatively rapid. A limited pull on and release of the cable [2 may therefore be used to control limited opening and, closing movement of the apron independently of any movement of the bowl floor. Following the initial limited movement of the apron, the roller ends of the arms 3.9 will contact and kick the bowl fiOOr 24, swinging the same from the down position of Fig; 1 toward the relatively upright dumping position of Fig. .2. The initial movement of the bowl floor is relatively slow and following deceleration of.

the upward movement of the apron. the movement of the floor toward its dumping position is accelerated. As long as the cable l2 is maintained in a taut wound condition by the tractor winch, the parts will remain in the dumping position of Fig. 2.. To return the parts to normal po ition it is merely necessary to slacheuup on the cable 12.. whereupon the floor and front apro com mence returning to their lowered p tions to gather. Toward, the lower end of its movement the apron accelerates dropping. It will be noted that the Weight f the front apronv is o war ly f its. axis of pivotal movement and hence ravity returns t to its d n position when the cable is: slack. The down m vement of e. p n imposes a p ll. on the flexible connections 51 which. through the levers 49, turns, the cros shaft 20. in a reverse irection and also swing ng o rctracti g he. arms 3 This is effective o withdraw or move th push. column. 29 rearwardly. Of: course as the arms 39: are withdrawn, the support. for the tilted floor 2.4 re edes and gravity causes: the floor to drop to it lowered position- Both the apron and the floor maintain their nor m l; lowered positions throu h gravity. and no springs or latches. are required for this purpose.

.As was previously suggest d, after the scrap r has been loaded, and the load is to e transported. the entire.- bowl assembly is eleva ed through a pull imposed on thecable l3. 'I'OcOnfine the load prior to dumping; the cutoff edge 48, of, the apron engages the bowl floor bladeZii.

As will be observed .from Figure 3., the, scraper is open on its top side, and there are no obstructions extended thereover. This adapts the scraper to being loaded by a power shovel when desired. It. will also be observed that the scraper is, underslung in character, and this, in addition to. the high front. frame. particularly adapt the scraper for use with a. high speed rubber tired ractor. The main operating. cable H, in the form of the invention described, is effective, When pulled to exert an endthrust on the rear end of the. longitudinally movable push column, and this in turn. swings the floor contacting arms 39 and revolves the cross shaft 2!] which then transmits a pullingfome t the apron through the connections described. The mechanical peration of. the scraper is very simple. result in a relatively inexpensive mechanism which i susceptible of being readily serviced by an average mechanic.

Fig, 4 illustrates the invention as applied to an hydraulically operated scraper; As the scraper proper i similar to that described in connection with the principal iorm of the invention, the description thereof will not be repeated, it being observed that those elements in Fig. 4 bearing primedref erence numeralseorrespond to the parts in Figs. 1 to 3, inclusive, bearing unprimed reference. numerals.

The scraper assemblage of Fig. 4, as in the principal form of the invention, includes a revoluble cross shaft 20 having a pair of joined complementary spaced apart arms 39' mounted fast at their upper ends on said cross shaft so as to turn therewith. The roller equipped lower ends of said arms are adapted to be swung through the bowl rear opening into contact with the track 43' on the bowl floor 24'.

The means for oscillating said arms comprise an hydraulic jack 1'5 intermediately pivotally mounted on a trunnion 16 within the housing 28. The piston rod H of the hydraulic jack extends to and is pivotally connected with the arms 39", as at 18. Thus, the projection of the piston rod ll of th hydraulic jack through the action of a fluid forced into the jack cylinder against the work surface of the piston rod piston will swing the arms 39' in a clockwise direction relative to Fig. 4, turning the cross shaft 20. This cross shaft carries angularly directed levers 49' from which are extended cables connecting with the apron 48. When turning movement is imparted to the shaft 20 in the proper direction, through movement of the arms 38', the apron 46' may be raised from a bowl closing position to a loading position, as in Fig. 4. Due to the fact that the arm 39' may have considerable movement before they engage and tilt the bowl floor 24', the limited opening and closing movement may be imparted to the apron 46' through a limited swinging movement of the arms independently of any movement of the bowl floor 24'. However, as in the principal form of the invention when the arms 39' are oscillated forwardly, there will first be the independent raising of the front apron 45 a limited distance. This initial movement of the apron is relatively rapid. As further movement is imparted to the arms 39' in the same direction, the roller ends of the arms will then contact and move the bowl floor 24' swinging the same toward a relatively upright dumping position, and this movement of the bowl floor is accompanied by an additional elevation of the apron. As was pointed out, the initial movement of the apron is rapid, and when the arms come into contact with the bowl floor, the initial movement of the bowl floor is relatively slow. However, continued upward movement of the apron is decelerated while continued upward movement of the bowl floor is accelerated.

In the hydraulically actuated arrangement shown in Fig. 4, there is another hydraulic jack 18 mounted relatively vertically on the front frame member It, the same being pivotally carried as at 80 on frame brackets 8|. Th piston rod 82 of said hydraulic jack depends and is pivotally connected with brackets 83 mounted on the transverse box section 62 on the forward portion of the bowl frame. It will, therefore, be evident that actuation of the hydraulic jack [9 is effective to cause jackknifing movements of th front frame and bowl frame relative to each other by which means the entire bowl assembly may be raised or lowered.

Fig. 5 illustrates schematically the hydraulic jacks, controls and fluid system for the form of the invention last described. An oil or hydraulic fluid supply tank i indicated therein by the numeral 84. In actual practice this tank may be mounted on the tractor (not shown) with which the scraper is connected for operation. Oil supply lines or conduits 85 and 86 connect with different portions of the supply tank or reservoir 84, the conduit 85 being a return conduit. Included in the other conduit and mounted wherever convenient, preferably on the tractor, is a conventional oil pump 81. The other ends of the conduits 85 and 85 enter and communicate with the chambers of a conventional two-way hydraulic valve 88, the latter being preferably mounted on the forward end of the scraper frame It) and having control levers 89 which extend forwardly so as to be accessible to the tractor operator. From the valve member 88 are conduits 98 and 9| which extend to and communicate with interior portions of the casing of the jack 19 on opposite sides of th jack piston 92. Also extended from the valve 88 are conduits 93 and 94, which communicate with different portions of the interior of the jack casing 15 on opposite portions of the piston 95 therein. Obviously, manipulation of the control lever 89 is effective to control the flow of oil under pressure through the various conduits for projecting or retracting the pistons in the hydraulic jacks l5 and 19. As was explained, operation of these hydraulic jacks is effective to raise and lower the entire bowl assembly and to manipulate the front apron 46' and to tilt or lower the bowl floor 24'.

From the foregoing description, it will be apparent that the improved scraper, whether cable or hydraulically actuated, utilizes a revoluble cross shaft to which motion is imparted by swingable arms, to control movement of the front apron and likewise thecross shaft and arm assembly is effective to raise and lower the bowl floor. The improved scraper is of simple and novel construction, is efiicient in operation, and is well adapted for the purpose described.

What is claimed as the invention is:

1. In a scraper, a front frame, a bowl frame pivotally connected with the front frame and including a bowl structure open at its front end, a wheeled support on which the bowl frame is pivotally mounted, said bowl structure including a rigidly mounted forward earth cutting blade, a movable bowl floor hingedly connected with said blade, and an apron pivotally mounted relative to the bowl structure and controlling the open front end thereof, oscillatable means mounted on the bowl frame, and means for transmitting motion from the oscillatable means to the apron to move the same so as to expose the front end of the bowl structure, the oscillatable means being spaced from but movable into engagement with the bowl floor to tilt the latter to a dumping position.

2. In a scraper, a front frame, a bowl frame pivotally connected with the front frame and including a bowl structure open at its front end, a wheeled support on which the bowl frame is pivotally mounted, said bowl structure including a rigidly mounted forward earth cutting blade, a movable bowl floor hingedly connected with said blade, and an apron pivotally mounted relative to the bowl structure and controlling the open front end thereof, oscillatable means mounted on the bowl frame, and means for transmitting motion from the oscillatable means to the apron to move the same so as to expose the front end of the bowl structure, the oscillatable means being spaced from but movable into engagement with the bowl floor to tilt the latter to a dumping position following a predetermined limited movement of the apron.

3. In a scraper, a front frame, a bowl frame pivotally connected with the front frame and including a bowl structure open at its front end, a wheeled support on which the bowl frame is pivotally mounted, said bowl structure including a rigidly mounted forward earth cutting blade, a movable bowl floor hingedly connected with said blade, and an apron pivotally mounted relative to the bowl structure and controlling the open front end thereof, oscillatable means mounted on the bowl frame and ultimately contactable with the bowl floor for causing the same to tilt to a dumping position, and a connection between the oscillatable means and the apron immediately effective upon movement of the oscillatable means to transmit motion from the latter to the apron to move the same so as to expose the front end of the bowl structure.

4. In a scraper, a front frame, a bowl frame pivotally connected with the front frame and including a bowl structure open at its front end, a wheeled support on which the bowl frame is pivotally mounted, said bowl structure including a rigidly mounted forward. earth cutting blade, a movable bowl floor hingedly connected with said blade, and an apron pivotally mounted relative to the bowl structure and controlling the open front end thereof, oscillatabl'e means mounted on the bowl frame andhaving a portion movable toward the bowl floor for causing the same to tilt to a dumping position when in contact therewith, means extending from the oscillatable means to the apron to transmit motion from the oscillatable means to the apron to move the latter so as to expose the front "end of the bowl structure, and means under the control of a single operating member and extending to said oscillatable means for swinging said osclllatable means in one direction, said oscillatable means being so mounted that gravity and the weight of the members operated thereby will cause the same to move in the I opposite direction.

5. In a scraper, a wheeled, articulated'supportin-g frame, a bowl structure included in a portion of said supporting frame and open at its front end, said bowl structure including a tiltable bowl ing frame, a bowl structure included in a portion of said supporting frame and open at its front end, said bowl structure including a tiltable bowl floor and a forward earth cutting blade with which said floor is hingedly connected, an apron pivotally associated with the bowl structure and controlling the open front end thereof, an arm mounted on the bowl structure and swingable in one direction to ultimately tilt and support the bowl floor, cable operated means associated with said arm to swing it in said direction, said arm being caused to swing in a return direction by gravity, and motion transmitting means between the arm and the apron for moving the latter when the arm is moved.

7. In a scraper, a frame, a bowl structure included in a portion of the frame and open at its front end, said bowl structure including a tiltable bowl floor and a forward earth cutting blade with which said floor is hingedly connected, an apron pivotally associated with the bowl structure and controlling the open front end thereof, a rigid reciprocatable member mounted in the frame, an arm swingably associated with the frame to move into contact with the bowl floor to tilt and support the latter, said arm being connected with the reciprocatable member to be impelled thereby, cable means applied to the reciprocatable member to move it in a direction to engage the arm with the bowl floor, and mechanical connections between the arm and the apron for causing the apron to move to bowl opening position immediately upon movement of the reciprocatable member in the stated direction.

8. In a scraper, a frame, a bowl structure included in a portion of the frame and open at its front end, said bowl structure including a tiltable bowl floor and a forward earth cutting blade with which said floor is hingedly connected, an apron pivotally associated with the bowl structure and controlling the open front end thereof, a push column reciprocatably movably mounted in the "mediately'upon movement of the push column in the stated direction.

:9. In ascraper, a frame, a bowl structure included in a portion of the frame and open at its front end, means closing the rear end of the bowl structure including a movable gate, said bowl structure including a til-tabl bowl floor and a forward earth cutting blade with which the floor is hingedly connected, an apron pivotally associated with the bowl structure and controlling the open front end thereof, a rigid reciprocatable member movably mounted in the frame, an arm oscillatably mounted relative to the frame and swingable in one direction to tilt and support the bowl floor, movement of the arm being accommodated by said gate in the rear closure of the bowl structure, said arm being connected with the reciprocatable member to be impelled thereby, cable means applied to th reciprocatable member to move it in a direction to engage the arm with the bowl floor, and mechanical connections between the arm and the apron for causing the apron to move to expose the front of the bowl structure immediately upon movement of the reciprocatable member in the stated direction.

10. A scraper, comprising a transportable frame having opposite side portions rigidly connected at their upper ends by a fixed rear wall section, there being an opening below said fixed rear wall section, the lower portion of said rear wall section hingedly carrying a dependin gate for a portion of said opening, a scraper blade interposed between said side portions forwardly of the rear Wall section, a relatively flat bottom plate hingedly supported adjacent said blade and having its rear portion swingable upwardly in proximity to said rear wall section and opening, the rear edge of said plate hingedly carrying an upstanding gate, the latter gate cooperating with the first-mentioned gate to close the opening below said rear wall section when the bottom plate is in a lowered position, a swingable arm mounted on the frame and movable into contact with said bottom plate to tilt and support it, said arm moving through said opening and swinging the depending gate to open position with the bottom plate carried gate moving away therefrom, and means associated with said arm for swinging the same.

11. A scraper, comprising a transportable frame, an open bowl carried by the frame, a relatively flat bottom plate Within said bowl and movable from a relatively flat lower position to a forwardly inclined tilted position, an apron pivotally mounted relative to the bowl and swingable generally outwardly upwardly relative to the bowl, and a unitary means movably mounted on the frame and normally spaced from said bottom plate and directly connected with said apron, said means being operable to first swing said apron and to subsequently engage the undersurface of said bottom plate to tilt the same, tilting movement of the bottom plate being accompanied by further swinging movement of the apron.

12. A scraper, comprising a transportable frame, an open bowl carried by the frame, a relatively fiat bottom plate hingedly mounted within said bowl and movable from a relatively flat lower position to a forwardly inclined tilted position, an apron pivotally mounted relative to the bowl and swingable generally outwardly upwardly relative to the bowl, and a single cabl actuated means movably mounted on the frame and directly connected to the apron but normally spaced from said bottom plate, said means being operable to first swin said apron and to subsequently engage the undersurface of said bottom plate to tilt the same, tilting movement of the bottom plate being accompanied by further swinging movement of the apron.

13. A scraper, comprising a transportable frame, an open bowl carried by the frame, a relatively flat bottom plate movably mounted within said bowl and shiftable from a relatively flat lower position to a forwardly inclined tilted position, an apron pivotally mounted relative to the bowl and swingable generally outwardly upwardly relative to the bowl, and hydraulically actuated means associated with the frame and normally spaced from said bottom plate and directly connected with said apron, said means being operable to first swing said apron and to subsequently engage the undersurface of said bottom plate to tilt the same, tilting movement of the bottom plate being accompanied by further swinging movement of the apron 14. In a scraper, a frame, a bowl structure included in a portion of the frame and open at its front end, said bowl structure including a tiltable bowl floor and an apron pivotally associated with the bowl structure and controlling the open front end thereof, a cross shaft revolubly mounted on the frame, an arm fast on said cross shaft and swingable toward and away from the bowl floor and normally in a position away from the bowl floor, an hydraulic jack connected with said arm to swing the same, and connections between the cross shaft and the apron whereby turning movement of the cross shaft is immediately effective to swing said apron relative to th bowl opening.

HENRY C. FRENCH. NORMAN V. KUEHLMAN.

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