US3693273A

US3693273A - Scraper apron for improved closing in rock

Info

Publication number: US3693273A
Application number: US97788A
Authority: US
Inventors: Robert J Sullivan
Original assignee: Caterpillar Tractor Co
Current assignee: Caterpillar Inc
Priority date: 1970-12-14
Filing date: 1970-12-14
Publication date: 1972-09-26
Anticipated expiration: 1989-09-26

Abstract

An apron carried below the floor of a scraper bowl and having the scraper cutting edge on the forward portion thereof is arranged for selective forced movement through the material ahead of the bowl in an upward and preferably forward direction to close the forward end of the bowl without interference to the closing action by rocks or other material.

Description

United States Patent Sullivan 1451 Sept. 26, 1972 [54] SCRAPER APRON FOR IMPROVED CLOSING 1N ROCK [72] Inventor: Robert J. Sullivan, Peoria, 111,

[73] Assignee: Caterpillar Tractor Co., Peoria, 111.

[22] Filed: Dec. 14, 1970 [21] Appl. No.: 97,788

52 us. 01. ..37/129, 37/126 AA 51 Int. Cl. ..E02p 5/00 58 Field of Search ..37/4, 124, 124 611, 126 R, 12 A 377/712,6 AA,1 26 AB, 126 AC, 126 AD, 126

AB, 127, 129,129 G, 117.5

[56] References Cited UNITED STATES PATENTS 2,422,985 6/1947 Reculer ..37/4 X 2,251,338 8/1941 McCollum ..37/126 AB 3,431,663 3/1969 Eiger ..37/126 R X 2,243,831 6/1941 Bemer ..37/4

2,548,754 4/1951 Vereschagin ..37/4 X 3,235,985 2/1966 Lauster ..37/4 UX 3,445,946 5/1969 Striggow ..37/4 X 3,197,048 7/1965 Hayes ..37/4 X 2,906,418 9/1959 Hayes ..37/4 X 2,125,558 8/1938 Grant ..37/126 AA FOREIGN PATENTS OR APPLICATIONS 762,157 7/1967 Canada ..37/4

Primary Examiner-Robert E. Pulfrey Assistant Examiner-Eugene H. Eickholt Attorney-Fryer, Tjensvold, Feix, Phillips & Lempio 5 7] ABSTRACT An apron carried below the floor of a scraper bowl and having the scraper cutting edge on the forward portion thereof is arranged for selective forced movement through the material ahead of the bowl in an upward and preferably forward direction to close the forward end of the bowl without interference to the closing action by rocks or other material.

13 Claims, 6 Drawing Figures PATENTEDsP2s I972 SHEET 1 BF 3 INVENTOR ROBERT J. SULLIVAN ATTORNEYS PATENTEDSEPZB I912 3.693.273

SHEET 2 OF 3 7 N N/AYN/N/N/N/NN/N N/NW/bV/AV/ INVENTOR ROBERT J. SULLIVAN P'A'TENTEDsms mm 3.693" 27 3 sneer a or 3 INVENTOR ROBERT J. SULLIVAN ATTORNEYS BY 0.; W1, 9%, 71:14; +4

SCRAPER APRON FOR IMPROVED CLOSING IN ROCK BACKGROUND OF THE INVENTION In conventional scrapers for earth moving operations, an apron is generally pivoted from a position above the scraper cutting edge to close the scraper bowl when it is filledwith the material being scraped. The ability of such an apron to close sufficiently when working in material such as rock and boulders, etc., is limited since rocks catch between the apron lip and the cutting edge, thereby holding the apron open to some extent and allowing finer material to leak out of the opening. This occurs primarily because the apron is required to force its way through compacted material in the apron zone immediately above the cutting edge. In addition, a conventional apron as carried upwardly and forwardly of the scraper bowl restricts to some extent the flow of rock and other material into the bowl.

SUMMARY OF THE INVENTION The present invention relates to a scraper apron for improved closing action in rock, and is more particularly directed to an apron which is carried below the floor of the scraper bowl with the scraper cutting edge at the forward portion of the apron, such apron being forced upward and preferably forward through material ahead of the bowl to close the forward portion of the bowl.

Inasmuch as the apron of the present invention closes from the bottom of the bowl upward, a positive closing action is obtained with no gap being left for the escape of soil or rock from the filled bowl.

As another advantageous feature, the apron is positioned rearwardly of the cutting edge and hence does not restrict the flow of material into the bowl. The bowl consequently acts like a carrying bulldozer, creating a substantially bulldozed pile in front of the cutting edge.

A further advantage with the apron of the present invention accrues from apron closing being only resisted by loose material in the bulldozed pile at the front of the bowl and not by tightly compact material. As a result, the hydraulic force required for closure is reduced compared to conventional scraper aprons.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of a tractor-scraper combination with portions of the scraper bowl brokenaway to show a scraper apron in accordance with the present invention.

FIG. 2 is an enlarged side sectional view of the bowl depicting the apron in retracted open position and the bowl in loaded condition.

FIG. 3 is a view similar to FIG. 2, but depicting the apron in closed position.

FIG. 4 is a view similar to FIG. 3 of a modified form of scraper apron.

FIG. 5 is a view similar to FIGS. 3 and 4 of another modified form of scraper apron.

FIG. 6 is a view similar to FIGS. 3, 4 and 5 of a further modified form of scraper apron.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION Referring now to FIG. 1 in detail, there is shown a tractor-scraper combination 11 including a tractor 12 coupled to a wheeled scraper how] 13. The bowl comprises side walls 14, a floor 17 rigidly transversely secured between the side walls adjacent their lower edges, and a rear wall in the form of an ejector l8 capable of being advanced through the bowl by a hydraulic cylinder shown at 19.

To the extent described, it will be appreciated that the scraper bowl of the tractor-scraper combination is of substantially conventional design. However, with a conventional bowl the scraper cutting edge is usually carried in fixed position at the forward end of the floor, and an apron carried at the front of the bowl pivots from above the cutting edge to close the forward end of the bowl subsequent to loading to retain the material therein.

Such a conventional apron arrangement is limited in its ability to close sufficiently when working in relatively rocky material since rocks catch between the apron lip and cutting edge, thereby jamming the apron open and allowing the finer material to leak out of the opening. Also, the apron as so positioned tends to restrict the flow of material into the bowl. The hydraulic force required to close the apron is relatively high inasmuch as the material above the blade which resists closure of the apron is highly compacted.

To obviate the foregoing difficulties and disadvantages of conventional scraper apron arrangements, the bowl 13 is provided with an apron 21 in accordance with the present invention which is arranged to close from the bowl floor 17 upwardly so no gap is left for soil or rocks to drop out. More particularly, in the preferred embodiment of FIGS. 1-8, the apron 21 is carried below the floor 17 of the scraper bowl and a scraper cutting edge 22 is rigidly secured to the forward portion of the apron.

The apron is selectively movable upward and forward from the retracted open position of FIGS. 1 and 2 to the closed position shown in FIG. 3. The apron is preferably arcuate and extends substantially the full inside width of the bowl between the side walls 14 thereof. The front and rear ends of the apron are provided with pairs of laterally projecting

pins

23 and 24 which slidably engage pairs of

guide slots

26 and 27 formed in the bowl side walls 14.

Slots 26 extend arcuately forward and upward from a position subjacent the forward end of bowl floor 17, while slots 27 are disposed subjacent the floor and extend arcuately from a position rearwardly of the floor to a position substantially adjacent the forward end thereof. Guided movement of the apron as determined by the pins engaging the slots is accomplished as by means of a hydraulic actuating jack 28 carried by the bowl and having its rod end pivotally connected to the rear end of the apron.

In the operation of the scraper apron 21 physically described above, the apron is retracted to the position shown in FIGS. 1 and 2 subjacent the bowl floor 17. At this time the scraper cutting edge 22 abuts the front end of the bowl floor, and the bowl is loaded in a conventional manner. Once the bowl is filled and the apron is to be actuated, jack 28 is extended to force the apron and its attached cutting edge 22 forwardly and upwardly through the bulldozed pile 29 of material immediately ahead of the bowl to the closed position shown in FIG. 3. The above-described action positively closes the front of the scraper bowl, with the rocks or other material not interfering with the closing action.

Since the apron closure is only restricted by the relatively loose material in pile 29, the hydraulic .force of jack 28 required to effect closure is less than with conventional designs. In addition, the apron does not restrict the flow of material into the bowl during loading by virtue of the apron being disposed subjacent the bowl floor.

Considering now several modified forms of scraper apron arrangements in accordance with the present invention, and referring first to FIG. 5, it is to be noted that a substantially straight apron 21' may be employed in place of the arcuate apron previously described. With the apron 21', the pins 23' engage guide slots 26 which include straight sections 31 extending longitudinally forward from positions subjacent the front end of floor 17 to terminate in sharply upwardly turned sections 32. The pins 24 engage linear guide slots 27' disposed in parallel subjacent relation to floor 17.

Thus, on being actuated to closed position, the apron 21 initially moves straight forward, then swings upward upon the pins 23 encountering the upwardly turned sections 32 of guide slots 26. The apron 21 is preferably formed with a relief, as shown at 33, in order to clear the front end of the bowl floor during upward movement of the apron.

As shown in FIG. 6, the bowl floor need not be flat, but rather may be curved as indicated at 17 to fit the arcuate apron 21. The

guide slots

26 and 27 in this case have the same curvatures and define a continuous arc.

The scraper edge 22 is located at the bottom of the are when the apron is in its retracted open position so that some reduction in ground interference is obtained.

Referring now to FIG. 4, there is shown a further modification of scraper apron arrangement which closes from the bottom of the bowl upward in accordance with the present invention. In this embodiment, an apron 21" is pivotally connected to the front end of bowl floor 17 to form a forward extension thereof. The scraper cutting edge 22" is secured to the forward end of the apron at suitable pivots 36. To actuate the apron 21" upwardly to closed position, lever arms 34 are secured adjacent the opposite side edges of the apron and project upwardly therefrom for connection to the rod ends of hydraulic jacks 28" secured to bowl sides 14 adjacent the upper edges thereof. Extension and retraction of the jacks effect downward and upward pivotal movement of the apron about pivots 36 to the desired open and closed positions.

Although the invention has been hereinbefore described and illustrated in the accompanying drawings with respect to several preferred embodiments, it will be appreciated that various modifications and changes may be made therein without departing from the true spirit and scope of the invention, and thus it is not intended to limit the invention except by the terms of the appended claims.

I What is claimed is:

1. In a scraper bowl including side walls, a floor rigidly transversely secured between the side walls adjacent their lower edges, and a rear ejector wall, the

combination comprising a scraper apron disposed subjacent said floor and extending transversely between said side walls, a scraper cutting edge secured to a forward end of said apron with respect to said floor, and wherein said apron has an open position with said cutting edge abutting the forward end of said floor, means mounting said apron for movement upwardly from said open position to an elevated closed position forwardly of said floor, and actuating means coupled to said apron for selectively moving same between said open and closed positions.

2. The combination of claim 1, further defined by said actuating means comprising a hydraulic jack carried by said bowl and pivotally connected to the rear end of said apron.

3. The combination of claim 1, further defined by said apron being arcuate.

4. The combination of claim 1, further defined by said apron being flat.

5. The combination of claim 3, further defined by said floor being curved to fit said apron in said open position thereof.

6. The combination of claim 1, further defined by the mounting means including means defining a first pair of guide slots in said side walls extending forward and upward from a position subjacent the forward end of said floor, means defining a second pair of guide slots in said side walls subjacent said floor extending forwardly to a point adjacent the forward end thereof, and first and second pairs of pins projecting laterally from the front and rear ends of said apron and respectively slidably engaging said first and second pairs of guide slots.

7. The combination of claim 6, further defined by said actuating means comprising a hydraulic jack carried by said bowl and having its rod end pivotally connected to the rear end of said apron.

8. The combination of claim 6, further defined by said apron being arcuate and said first and second pairs of slots being arcuate.

9. The combination of claim 6, further defined by said apron being flat, said first pair of slots including straight sections extending longitudinally forward from positions subjacent the front end of said floor to terminate in sharply upwardly turned sections, and said second pair of slots being linear and disposed in parallel subjacent relation to said floor.

10. The combination of claim 8, further defined by said floor being curved to fit said apron in said open position, and said first and second pairs of slots having the same curvature and defining a continuous are, said cutting edge being located at the bottom of said are when said apron is in said open position.

11. The combination of claim 8, further defined by said actuating means comprising a hydraulic jack carried by said bowl and having its rod end pivotally connected to the rear end of said apron.

12. The combination of claim 9, further defined by said actuating means comprising a hydraulic jack carried by said bowl and having its rod end pivotally connected to the rear end of said apron.

13. The combination of claim 11, further defined by said floor being curved to fit said apron in said open position, and said first and second pairs of slots having the same curvature and defining a continuous arc, said cutting edge being located at the bottom of said are when said apron is in said open position.

Claims

1. In a scraper bowl including side walls, a floor rigidly transversely secured between the side walls adjacent their lower edges, and a rear ejector wall, the combination comprising a scraper apron disposed subjacent said floor and extending transversely between said side walls, a scraper cutting edge secured to a forward end of said apron with respect to said floor, and wherein said apron has an open position with said cutting edge abutting the forward end of said floor, means mounting said apron for movement upwardly from said open position to an elevated closed position forwardly of said floor, and actuating means coupled to said apron for selectively moving same between said open and closed positions.

3. The combination of claim 1, further defined by said apron being arcuate.

4. The combination of claim 1, further defined by said apron being flat.

10. The combination of claim 8, further defined by said floor being curved to fit said apron in said open position, and said first and second pairs of slots having the same curvature and defining a continuous arc, said cutting edge being located at the bottom of said arc when said apron is in said open position.

13. The combination of claim 11, further defined by said floor being curved to fit said apron in said open position, and said first and second pairs of slots having the same curvature and defining a continuous arc, said cutting edge being located at the bottom of said arc when said apron is in said open position.