GB2173530A - Machine for digging or clearing ditches - Google Patents

Abstract

A ditch cleaning or digging machine comprises an attachment for the front of a tractor, including a support structure (1,2), a laterally and upwardly extending arm (3) attached thereto, and a downwardly extending arm (6) pivoted to the upper end of the first arm. A ram (17) actuates a linkage to control the attitude of the arms, and a paternoster conveyor (8) with blades is arranged to propel cleaning or digging head along the ditch and also to carry away spoil. A nose cone (14) may be driven by the conveyor and this may also have cutting and propelling blades. <IMAGE>

Description

SPECIFICATION Ditch digging and ditch maintenance machine The invention relatestoa machinefordigging or maintaining ditches and is especially although not exclusively suited to being mounted on a vehicle such as a farm tractor.

Machines have already been proposed which are designed to dig ditches. These have tended to be expensive and are not sufficientlyversatile for use in maintaining ditches which have alreadybeen dug by other means.

The machine ofthe invention has primarily aimed at the maintenance and cleaning of existing ditches, although with suitable modifications it may be used for digging new ditches. In a structure ofthis kind, if of lightweight and thus inexpensive construction necessary if it is to be tractor mounted, severe stresses are imposed due to the distance ofthe operating head from the mounting point.

In accordance with the invention such a machine comprises a support structure for mounting on a vehicle such as a farm tractor, a downwardly extending arm carried by the support structure with means for adjusting the angle between the two so asto permitthe arm to be aligned with the slope ofthe ditch side, a digging head atthe lower end of the arm and having a pulley over which passes a paternoster converyor extending along the length ofthe arm and being provided with scraper blades and power means for driving the conveyor.

The cleaning or digging head may also have a nose cone mounted ahead ofthe conveyor pulley and driven thereby, the nose cone having peripheral cutting bladesfor cutting through the soil of the ditch bottom. Preferablythe conveyor blades orthe nose cone blades or both are angled so that when driven they exert a screw action on the soil in the ditch so as to propell the head and the arm forwards along the ditch.

The above and otherfeatures of the invention will appearfromthefollowing description having refer enceto the accompanying drawings, in which: Figure lisa perspective view of part of a tractor to which a device according to one form of the invention has been fitted.

Figure 2 is a view from the front of the draining or digging head ofthedeviceof Figure 1, Figure 3 is a corresponding view from behind, and Figure 4 is a detail of a soil removing mechanism.

Referring firstto Figure 1, a tractor has secured to it a front mounting plate 1 which projects forward to a position where a triangular frame 2 is articulated to it on a vertical hinge. Extending away from the sloping portion ofthetriangularframe is a double wishbone structure 3, 4which forms a parallelogram linkage with a pair of plates 5 which form the upper part of a downwardly extending arm 6. The arm 6 carries at its lower end a pulley7, seen in Figure 3, and an agricultural type chain 8 extends along each side of the arm 6 around the pulley 7 and around a driving cog (not shown) which is driven by a hydraulic motor 9 through suitable reduction gearing.The chain 8 is provided at intervals with plates 10, each of which carries a scraper blade 11 in a sloping attitude across the chain and provided with a more steeply raked cutting portion 12. The pulley7 is carried on bearings on a stubshaft supported by a bracket 13 extending from the lower end ofthe arm 6 and has attached to its forward face a nose cone 14 provided with scraper blades 15 on its face and with angled cutting blades 16 around its periphery.

A hydraulic ram 17 is provided to lower and raise the parallelogram linkage and when this is done the arm 6 - is moved into or out of a ditch, its attitude however, remaining constantthroughoutthe movement. The actual anglethatit makes with the horizontal can be adjusted by a bottle screw 18so as to cater for different ditch bank angles. The motor 9 drives the chain Sin a direction such asto move the pulley7 anti-clockwise so thatthe cutting blades 16tendto screwtheirway through the soil and drag the lower end ofthe arm 6 forward to correspond with movement ofthe tractor.

This action is augmented by the angled arrangement ofthe blades 11 which remove soil and detritus from the bottom and sides oftheditch. In orderto ensure that such material is deposited clear of the ditch a mould board 19 is provided on the upward innerside of the conveyor so that material tends to be retained ontheblades 11 which are madewith achannel section. When the blades reach the top ofthe board 19 the material isfreeto fall off, however some of it may tend to stickto the blades and a scraper arm 20 is provided pivoted on a cross shaft 21 on the arm 6.This may be spring-loaded so as to be biased towards the position illustrated in Figure 4, so that as each blade 11 is carried past it the chisel edge 22 scrapes along the base ofthe blade while being lifted by itagainstthe spring action and after the blade has passed andthe material has been scraped off it drops back into position ready for the next blade. Since it may be desirable on occasionsto reverse the direction of movement ofthe chain the cross-shaft 21 is connected buy a linkage 23 to a combined slipping crutch and free-wheel mechanism 24, which pul Is the scraper arm 20 out ofthe line of the scraper blades 11 wheneverthe chain direction is reversed.

The mould board 19 is continued down around the bottom ofthe pulley7 so asto ensurethatthe material scraped off by the blades 11 is not redeposited into the ditch and the far end ofthis extension 24 is supported by a strut 25. So that the cutting head does not penetrate too deeply into the ditch soil, a shoe 26 is provided extended rearwardly from the back of the lower portion ofthe mould board 19.

It maybe desirable forthe scraper blade 20to be driven positively and in this eventthe linkage 23 can be operated by a crank or cam from the drive mechanism and its movement arranged to syntchro- nise with the passage ofthe blades 11.

In the eventthatthe cutting head encounters an obstruction or ifthetractor is being driven ata speed greaterthan can be achieved bythe cutting head itself then a strain would ordinarily be imposed on the mechanism and its supporting structure. In order to reduce the possibility of damage the frame 2 is pivoted on the end of the mounting plate 1 and is urged into its normal position by a rod connected to an offset bracket 27, which passes through a fixed bracket 28, and istensioned by a compression spring 29. Thus when resistance is encountered the bracket2 will rotate somewhat and this can be arranged eitherto operate an indicatorto warn the driver or it can trip a valve which causes the ram 17 to withdrawthe arm 6 from the ditch.

In an alternativearrangementinstead of providing the parallelogram linkage for raising and lowering the arm 6,thearm could be mounted on an extension ofa fore-loaderorif desired a rear-loaderinthecase where the latter has sufficient vertical movement. In these cases, however, it will be necessaryto ensure thatthearm 6 remains in a vertical plane and this can be achieved usually be pivoting a boom across the tractor and attaching a tension wire from as upstanding parttoafixed point above the pivot points of the loader.

It may be desirablethatthe arm 6 should be urged towardsthe nearside bank of the ditch in orderto effect efficient cleaning thereof, and this may be achieved hydraulically by means ofthe ram 17 or alternatively spring loading can be applied at any convenient point in the parallelogram linkage.

In a modifiedform ofthe invention,the bottle screw 18 may be backed up by a hydraulic ram. This will permitthe arm 6to be raised independently ofthe parallelogram linkage so as to lift it over a hedge or fence, for example. It may also serve to determine the armanglein place ofthe bottle screw 18.

Claims (10)

1. A machine for digging and or cleaning ditches, comprising a support structure designed to be mounted on a vehicle, a laterally extending arm carried bysaid support structure, means for raising and lowering the upper end of said arm, a downwardly extending arm connected to the upper end of the first arm, means for adjusting the angle between the two arms, said downwardly extending arm being provided with a cutting head shaped to conform to a desired ditch bottom contour,and a conveyor arranged to carry spoil from said cutting head to a point where the spoil drops offthe conveyor clear ofthe ditch.

2. A machine according to Claim f, wherein said cutting head comprises a rotarycutterwith a rotary nose conethe point of which faces forward ofthe ditch.

3. A machine according to Claim 2, wherein the nose cone has cutting blades which are angled to propel the cutting head forward along the ditch.

4. A machine according to Claim 2orClaim 3, wherein the cutter is driven by the chain conveyor, which itself is driven bya motor mounted nearthe upperend ofthe downwardly extending arm.

5. A machine according to Claim 4, wherein the chain conveyor has blade lugsfortransporting the spoil which arethemselvesangledto impartaf6rward motion to the cutting head.

6. A machine according to any one ofthe preceeding claims, wherein the chain conveyor has a scraper blade pivoted on the downwardly extending arm and operative to scrape away spoil from each blade ofthe conveyor as it passes.

7. A machine according to Claim 6,wherein the scraper blade is biased towards the conveyor blades and is moved bythem againstthe blades to scrape away the spoil.

8. A machine accordingto Claim 6, wherein a positive reciprocating motion is imparted to the scraper bladewhich is synchronised with the passage passed itofthe blades of the conveyor.

9. A machine according to Claim 7, wherein a reverse motion ofthe conveyor causes the scraper blade to be retracted clear ofthe conveyor blades.

10. A machine for digging orcieaning ditches substantially as herein described with reference to the accompanying drawings.