GB2391032A

GB2391032A - Method and apparatus for excavating a subterranean drainage channel

Info

Publication number: GB2391032A
Application number: GB0324884A
Authority: GB
Inventors: Motoji Nishiguchi
Original assignee: Unit Shoji Ltd YK
Current assignee: Unit Shoji Ltd YK
Priority date: 1999-10-06
Filing date: 1999-10-06
Publication date: 2004-01-28
Anticipated expiration: 2019-10-06
Also published as: EP1091047A3; JP4615688B2; GB0324884D0; GB9923634D0; JP2001107346A; GB2355031A; GB2355031B; EP1091047A2; EP1091047B1; GB2391032B

Abstract

An apparatus comprise an excavator, able to be pulled by a tractor 10, having an endless chain 24 with excavating buckets 25 attached, a reformer knife 31 to form a slit space, a pressing member 32 attached to the reformer knife, which scrapes earth from the sidewalls of the slit space and forces the earth backwards through a narrow gap to close the slit space and create an enclosed subterranean drainage channel, S. The excavated earth H(T), is transported to a discard section where it is scattered from the rear of the excavator in order to fill the upper part of the slit space. A control system incorporates laser guidance apparatus 51, to move the excavator up or down, allowing the excavator to be used to form inclined drainage channels.

Description

2391 032

- 1 Devic. and Method for Excavating Underdrainage.

The present invention relates to a device for excavating an underdrainage in the 5 ground (that is a subterranean drainage), a system for excavating an underdrainage and a method for excavating an underdrainage and more particularly to a device for positively excavating an underdrainage in the ground, a system therefor and a method therefor by reforming the lower part of a slit space formed by means of excavating buckets to close the intermediate portion of the slit space.

10 It is well known that a device for excavating an underdrainage within the ground is used in order to drain the residual surface water or excess moisture within the ground such that an aquatic environment or soil condition suited to field cultivation is built.

Japanese Pat. Appin. Pub. No. 90036 discloses a device for excavating an underdrainage comprising an excavator composed of buckets attached to an endless 15 chain, a slit reformer knife member arranged rearwardly of said excavator taken in the direction of excavating work, a pressing member attached to said slit reformer knife member at a vertical intermediate portion thereof, and a casing having a dirt discard opening rearwardly of a top position each bucket takes. Said device for excavating an underdrainage is adapted to discard the excavated dirt into said casing while pressing 20 the vertical intermediate portion of the slit by means of said pressing member to close the slit such that an underdrainage is formed. As a result, the upper part of the reformed slit space is filled with the dirt discarded by each bucket at the time of transition from an upward run to a downward run thereof such that the slit is covered to prevent an unnecessary falling of outside dirt thereinto which might lead to a closure of said 25 underdrainage. The underdrainage excavating device of this type has another problem of excavating an underdrainage substantially in parallel with the ground surface, said underdrainage lacking in an incline with the result that surplus water in the ground can stay there to mar the drainage performance.

30 In order to solve the problems referred to in the foregoing, the present invention has an object to provide a device, a system and a method for excavating an underdrainage, which are capable of forming an underdrainage with a good drainage.

In one aspect of the invention, there is essentially provided a device for excavating an underdrainage comprising an underdrainage excavator having an endless chain with excavating buckets attached thereto with a predetermined spacing therebetween; a reformer knife provided rearwardly of said underdrainage excavator 5 taken in the direction of an excavating work to form a slit space; a pressing member attached to said reformer at a vertically intermediate portion thereof to scrape off dirt from both intermediate sides of said slit space and press said scraped off dirt such that said slit space is closed to form an underdrainage in the ground; and a discard section: provided rearwardly of said underdrainage excavator taken in the direction of excavating 10 work for scattering the dirt excavated by said excavating buckets over the ground.

In another aspect of the invention, there is provided a device for excavating an underdrainage comprising an underdrainage excavator having an endless chain with i excavating buckets attached thereto with a predetermined spacing therebetween; a: reformer knife provided rearwardly of said underdrainage excavator taken in the direction 15 of an excavating work to excavate a slit space; and a pressing member attached to said reformer knife at a vertically intermediate portion thereof to scrape off dirt from both I intermediate sides of said slit space and press said scraped off dirt such that said slit space is closed to form an underdrainage in the ground, said underdrainage excavator being adapted to be raised and lowered to reform said slit space while being hauled by 20 said tractor such that said pressing member forms an inclined underdrainage.

In a further aspect of the invention, there is further provided a device for excavating an underdrainage comprising an underdrainage excavator having an endless chain with excavating buckets attached thereto with a predetermined spacing therebetween; a reformer knife provided rearwardly of said underdrainage excavator I 25 taken in the direction of an excavating work to excavate a slit space; and a pressing member attached to said reformer at a vertically intermediate portion thereof to scrape off dirt from both intermediate sides of said slit space and press said scraped off dirt I such that said slit space is closed to form an underdrainage in the ground; and a tractor! 30 having said underdrainage excavator attached thereto and having a lift mechanism to I raise and lower said underdrainage excavator; and control means for driving said lift mechanism such that said underdrainage excavator forms an inclined underdrainage in; said ground.

in a still further aspect of the invention, there is provided a method excavating an underdrainage comprising the steps of reforming an excavated space to form a slit space; scraping dirt from both sides of said slit space at a vertically intermediate level; pressing said scraped dirt such that said slit space is closed to form an underdrainage 5 therebelow; and scattering the excavated dirt by means of an excavator over the ground surface. In a still further aspect of the invention, there is provided a method for excavating an underdrainage comprising the steps of reforming an excavated space in the ground to form a slit space; scraping off dirt from both sides of said slit space at a vertically 10 intermediate level; and pressing said scraped dirt such that said slit space is closed to form an underdrainage space therebelow; characterized in further including the step of raising and lowering an excavator while said excavator being hauled by a tractor such that said excavator excavates the ground to form an inclined underdrainage A device system and method for and of forming an underdrainage will now be 15 described by way of example with reference to the accompanying drawings, in which, Fig. I is a side elevation of a first embodiment of device for excavating I underdrainage attached to a tractor; Fig. 2 is a rear view of the tractor of Fig. 1 without the parts rearward of a slit reformer knife 20 Fig. 3 is a rear view of the underdrainage excavating device in Fig. 2; Fig. 4 is a perspective view of a presser member; Fig. 5 is a sectional plan view showing the presser member of Fig. 4 in operation; Fig. 6 is a side elevation of a dirt discarding section; Fig. 7 is a plan view of the dirt discarding section; I 25 Fig. 8 is a front view of the dirt discarding section; Fig. 9A is a plan view of the rotary plate, Fig. 9B is a front view thereof and Fig. 9C is a side elevation thereof; I Fig. 10 is a diagram of a link mechanism in the tractor;! Fig. 11 is a vertical cross section of a slit space; 30 Fig. 12A is a diagram plan view of the presser member in operation and I Fig. 12B is a vertical cross section diagram of the presser member; Fig. 1 3A is a diagram plan view of the slit space being reformed by the slit; reformer knife and Fig. 13B is diagram plan view in cross section; and

Fig. 14 is a see elevation of the underdrainage excavating device of the invention in operation.

Referring to Fig. I through Fig. 14 showing a preferred embodiment of the invention, in which a well known crawler type tractor 10 is equipped with an 5 underdrainage excavator 20 actuated by means of a link mechanism composed of an upper link 11, a lower link 12 and a lift link 13; that is, said underdrainage excavator 20 is hauled and controlled through an operation of the upper link 11 and the lower link 12 which respectively act as a three point link. As shown in Fig. l through Fig. 3, said underdrainage excavator 20 is equipped with a mast 21 supported by said link 10 mechanism, the top of said mast 21 being attached with sprocket wheel 22. Said mast 21 has a guide plate 24A, which will be explained later in detail, extending downward.

Said guide plate 24A is attached with a sprocket wheel 23 which forms a pair together with said sprocket wheel 22 such that said sprocket wheels 22 and 23 are driven by way of axles 22A and 23A.

15 An endless chain 24 is passed around said sprocket wheels 22 and 23, excavating pawls 25 are attached to said chain with predetermined spacings therebetween. Said chain 24 is adapted to move along the periphery of a guide plate 24A extending downwardly of said mast 21, said guide plate 24A functioning to prevent the distance between the tense side of the chain 24 and the slack side of the chain 24 20 from becoming less while providing a support of the sprocket wheel 23. The axle 23A of said sprocket wheel 23 is provided to rotate on the guide plate 2 4A. Each bucket-like excavating pawl 25 is attached with a predetermined orientation such that each bucket-

like excavating pawl 25 running on the tense side performs an excavating work on the ground surface to be excavated by moving from below to above while the bucket-like 25 excavating pawl 25 on the slack side thereof does no work.

There is further provided a drive sprocket 26 to drive the axle 22A of the sprocket wheel 22, said drive sprocket 26 having an axle coaxially with said axle 22A such that a torque is transmitted from the tractor 10 by way of the chain 27 (a drawing of an output 30 sprocket wheel on the tractor side is omitted). With this structure, the tense side of the chain 24 is driven such that the tense side shows an upward motion while the slack side shows a downward motion.

Further, there is a casing 28 provided rearwardly of the uppermost end of said mast 21, in other words, rearwardly taken in the direction of excavating work, said casing

- 5 28 being formed with an opening 28A for discarding the dirt excavated by means of said excavating pawls 25. Said casing 28 has a shutter 28B for downwardly guiding the dirt discarded from said opening28A. Therefore, the excavated dirt is discarded through said opening 28A at the time of each bucket-like excavating pawls 25 reversing its 5 motion from the ascending run to the descending run rurner to be guided downwardly by said shutter 28B.

Most of said discarded dirt is scattered over the ground such that part thereof is -

filled into the upper part of a slit space S which will be explained later, said slit space S being covered with a soil lid H. 10 Further, a reformer knife 31 is provided in a plane containing said guide plate 24A provided rearwardly of said mast 21 taken in the direction of the excavating work, said reformer knife 31 being adapted to reform said slit space S formed by said excavating pawl 25. Further, said reformer knife 31 has a pressing member 32 attached at a vertically intermediate portion thereof, said pressing member 32 being adapted to 15 press the dirt scraped off from both sides such that said slit is closed.

In other words, said reformer knife 31 having a relatively thin vertically elongate configuration follows the inside of the slit-like space excavated within the ground, said reformer knife 31 being attached with said pressing member 32. As shown in Fig. 1, said pressing member 32 is attached to said knife 31 at a vertically intermediate portion 20 thereof within the ground. Further as shown in Fig. 4 and Fig. 5, said pressing member 32 is shaped like a gate as viewed from behind and like a modified trapezoid in plan view having rearwardly converging sides. Said pressing member 32 is composed of a base plate 32A and side plates 32B bent therefrom at a right angle. Since said base plate is shaped like a modified trapezoid, the space defined by said side plates 32B 25 becomes rearwardly increasingly narrower in the direction of excavating work. Said reformer knife 31 is slightly wider than that of the slit space in the ground while the opening defined between the rearmost ends of said side plates 32B of the presser member 32 is substantially wider than the width of the slit space S. further, as shown in Fig. 1, there is provided a space forming plate 33 attached 30 to said knrfe at a lower part thereof and forwardly thereof taken in the direction of the excavating work, said space forming plate 33 being substantially circular such that the space formed by said excavating pawls 25 is enlarged at a lower part thereof. The lowermost end of said space forming plate 33 is positioned at a lowermost level of the locus of the chain 24 such that an excavating pawl 25 is seen protruding downwardly of

! said space forming plate 33 as viewed from behind in the direction of the excavating work. Further as shown in Fig. 6 and Fig. 8, there is provided a scattering section 40 rearwardly of said mast 21 taken in the direction of the excavating work. Said scattering 5 device 40 is equipped with a support member 4i attached to line casing 28, gear box 42 in turn attached to said support member 41 and rotary plate 43 attached to an axle 42A of said gear box 42 to rotate in a horizontal plane. Said gear box 42 has an axle 42B attached with a sprocket wheel 44 while the axle 22A is attached with a sprocket wheel 45. An endless chain 46 is passed around said sprocket wheels 42 and 45 such that the 10 chains 24 and 46 are driven by a drive source on the tractor side. As shown in Fig. 9, said rotary plate 43 is attached with four vanes 43A extending radially with an equal angular distance therebeNveen about said axle 42A. The excavated dirt T falls on said rotary plate 43 to be deflected by said vanes 43A to be scattered onto the ground surface. 15 As shown in Fig. 1, a laser beam receiving section 51 to receive a slope signal L in the form of a laser beam indicating a slope at an angle to a horizontal reference plane is attached by way of a pole 51X to an appropriate portion of the mast 21 at a position due above thereof in side elevation. Then, the underdrainage excavating device 20 is controlled to be raised or lowered by the output from the tractor such that the laser beam 20 receiving section 51 is to stay in a laser beam plane. Said lift cylinder 16 is controlled by slope signal L from the laser emitting section 53 to expand and contract by being driven by a hydraulic pressure from a hydraulic pump 56 equipped in the tractor 10 by way of a selector switch 55 and a flow rate control valve 57. In other words, the slope signal L received by the laser receiving section 51 is input into a control circuit 54 having a 25 controlling microcomputer such that said selector valve 55 is select controlled on the basis of the control signal output from said control circuit 54 to control the valve opening area of said flow rate control valve 57. In this connection, the laser emitting section 53 is located at an appropriate position away from the field being worked on and is adapted to

30 rotate in a plane at an angle to a horizontal reference plane while emitting a laser beam to draw an imaginary inclined laser beam plane in the air.

Next, the manner of underdrainage excavating work by using the device for excavating an underdrainage according to the present invention will be shown in Fig. 11.

First of all, at a field being worked on for excavating an underdrainage, the device 20 for

i - 7 excavating an underdrainage attached to the tractor 10 is lowered by operating a let mechanism of the tractor 10 before the tractor 10 is run while supplying a driving force to the axle 22A of the sprocket wheel 22 by way of the sprocket wheel 26. At an early stage, the excavating pawls 25 may not stick into the earth but, as the tractor 10 proceeds, line excavating pawis 25 start to stick into the ground to pierce tnereino while excavating the ground down to the predetermined depth. At this time, the excavated dirt is carried by the excavating pawls 25 in the upward run thereof before, as said excavating pawls 25 changes its course from the upward run to the downward run, the dirt carried by the excavating pawls 2S is discarded downward by way of discard opening 10 28A in the casing 28 by the shutter 28B. Thereafter, the vane 43A provided on the rotary plate 43 deflects the dirt falling onto the rotary plate 43 to be scattered over the ground.

Substantially along the excavating work line in the field, a slit space S is formed as

shown in Fig. 11 by means of said buckets-like excavating pawls 25. Then, after the passage of the slit reformer knife 31 and the pressing member 32 provided rearwardly of 15 said excavating pawls 25, the dirt pressed and hardened by said pressing member 32 is left in the form of a crossbeam extending horizontally to provide vertical blockage of the slit S. Then, rearwardly of said excavating pawls 25, part of the excavated dirt T being scattered falls drawing an arc into said slit space S as shown in Fig. 14. Said excavated dirt T falls into said slit space S formed after the passage of the slit reforming knife 31 a 20 such that the upper part of the slit space S is closed as if a lid H is placed thereover.

(Fig. 13) In other words, before part of the excavated dirt T is scattered, the slit space is reformed by the slit reforming knife 31, the slit space T opening at K as shown in Fig. 11.

However, part of said excavated dirt T scattered into an air rearwardly of said slit reforming knife 31 falls into said slit space S to accumulate and cover the upper part 25 thereof in the form of the lid H to close the upper part of the slit because the slit space is closed at a vertically intermediate portion. Particularly, at a peat bog in general, the peat bog dirt at the mid-depth of the slit S of 70 cm from the ground surface is scraped off from both sides of the slit space S and pressed by the pressing member 32 after the passage of the tractor 10 to provide a blockage in the form of a crossbeam in said slit 30 space S. In other words, when the underdrainage excavating device 20 of the present invention is hauled by the tractor 10;the slit space S is blocked by said cross beam of dirt formed by the pressing member 32 because a space defined by the side plates 32B of the pressing member 32 becomes increasingly narrower. Then, part of the excavated

- 8 dirt being scattered is accumulated above said cross beam of dirt formed by the pressing member T to block the slit space, thus forming an underdrainage further preventing the entry of dirt. (Fig. 1 3B) There are formed a confined part of the slit space and an underdrainage space formed by the passage of the space forming plate 33. Being 5 separated from outside, said underdrainage space is free from entry of the dirt to erasure a long term maintenance of the space as an underdrainage such that the moisture contained in the peat bog dirt oozes out to be drained.

In the operation state above, the lift cylinder 16 shown in Fig. 10 receives the slope signal L issued from the laser emitting section 53 for the controlling purpose. In 10 other words, the lift cylinder 16 is adapted to be extended and contracted such that the laser beam receiving section 51 always stays in the inclined laser beam plane defined by the inclined plane signal L, thus controlling the vertical position of the underdrainage excavating device 20.

As stated in the foregoing, the underdrainage excavating device 20 is capable of 15 excavating an inclined underdrainage space by ensuring that the laser beam receiving section 51 is kept within said plane defined by inclined plane signal L because the underdrainage excavating device 20 performs an operation in a predetermined inclined plane. If the laser beam receiving section 51 goes off the inclined laser beam plane 20 defined by the inclined signal L issued from the laser beam emitting section 53, the control signal from the control circuit (control box) 54 for the lift mechanism is issued to switch the hydraulic circuit. For example, if the tractor 10 rides over a raised portion in the field, the laser beam emitting 53 is raised above the inclined plane L. With said laser

beam receiving section 51 thus going off the inclined plane, the control circuit (control 25 box) 54 issues a control signal, in accordance with which the hydraulic circuit is switched. In other words, to ensure that the inclined plane signal L is received, a signal to instruct that the laser beam receiving section 51 be lowered is issued such that the selector valve 55 is switched over to extend the lift cylinder 16. At this time, the pressure oil is pressed toward the direction to control the orientation of the underdrainage 30 excavating device 20 such that the forward end thereof is lowered by actuating the rod 16A of the lift cylinder 16 into the direction to extend the same. As a result, the lift arm 15 is rotated to press the lift rod 13 to lower the lower link 12 until the laser beam receiving section 5t is lowered down to the level to receive the inclined plane signal L

- 9 - where the forward end of the underdrainage excavating device 20 is positioned to do the desired excavating work.

In other words, if the laser beam receiving section 51 goes off the inclined plane of the inclined plane signal L issued from the laser beam emitting section 53 to indicate 5 that the underdrainage excavating device goes off the desired level, fine extent OT deviation of the laser beam receiving section 51 off the inclined plane is calculated at the control box (control circuit) such that the amount of correction is determined. Then, a signal corresponding to the correction is input into the hydraulic circuit of the lift mechanism equipped in the tractor 10 to control and drive the lower link 12 by way of the 10 lift rod 13. Thus, the orientation of the underdrainage excavating device 20 is controlled such that the laser beam receiving section 51 is located in the inclined plane referred to in the foregoing. As a result, the underdrainage having a slope (inclination of) is excavated in the ground as shown in Fig. 14.

As clearly understood from the explanation in the foregoing, the underdrainage 15 excavator according to the invention scatters the excavated dirt over an extended area of the ground surface to prevent the excavated dirt from accumulating in the form of mounds in a localized area along the slit space to cover the grass or pasture while part of the excavated dirt is filled into the upper part of the slit space, thus preventing an entry of any dirt from outside. Further, the excavating device of the invention is controlled to 20 change its level in accordance with a inclined reference plane while being drawn by a tractor to ensure that the device excavates the ground to form an inclined underdrainage which shows excellent drainage performance.

Claims

- 1o - CLAIMS

1. A device for excavating an underdrainage while being hauled by a tractor, comprising an underdrainage excavator adapted to be raised and lowered while 5 excavating such that an inclined underdrainage is formed, said device comprising an endless chain with excavating buckets attached thereto with a predetemmined spacing therebetween; a reformer knife provided rearwardly of said underdrainage excavator taken in the direction of an excavating work to excavate a slit space; 10 a pressing member attached to said reformer knife at a vertically intermediate portion thereof to scrape off dirt from both intermediate sides of said slit space and press said scraped off dirt such that said slit space is closed to form an underdrainage in the ground; and a discard section provided rearwardly of said underdrainage excavator taken in 15 the direction of excavating work for, scattering the dirt excavated by said buckets over the ground.

2. A device for excavating an underdrainage as set forth in claim 1, further comprising means for receiving a laser beam emitted from a desired location away from 20 the field to be worked on, to draw an imaginary slope inclined at an angle to a reference

horizontal plane, said underdrainage excavator being adapted to be raised and lowered in accordance with a laser beam signal received by said laser beam receiving means.

3. A device as set forth in claim 1 further comprising 25 a lift mechanism for attachment to said tractor, to raise and lower said underdrainage excavator; and control means for driving said lift mechanism.

4. A device as set forth in claim 3, wherein said underdrainage excavator further 30 comprises means for receiving a laser beam emitted from a desired location away from the field being worked, to draw an imaginary slope inclined at an angle to a reference

horizontal plane, said control means being responsive to said laser beam receiving means.

(

5. A method of excavating an underdrainage comprising the steps of reforming an excavated space to form a slit space; scraping dirt from both sides of said slit space at a vertically intermediate level; 5 pressing said scraped dirt such that said slit space is closed to form an underdrainage therebelow; scattering the excavated dirt by means of an excavator over the ground surface; and raising and lowering said excavator while being hauled by a tractor, such that the 10 ground is excavated to form an inclined underdrainage.

6. A method of excavating an underdrainage as set forth in claim 5, wherein said raising and lowering step includes the scanning of a laser beam in a beam plane at an angle to a reference horizontal plane, said excavator having means for receiving said 15 laser beam in said beam plane.

7. A device for excavating an underdrainage as herein described with reference to figures 1 to 14.

20

8. A method of excavating an underdrainage according to claim 5 and as herein described.