GB2115038A - Digging apparatus - Google Patents

Abstract

Apparatus for digging rectangular holes, comprising a supporting structure (3) for resting on the ground, and power-driven recirculatory digging means (7) mounted on said supporting structure (3) for up and down movement, the effective digging area of said digging means (7) in operation comprising substantially only a substantially horizontal bottom run or runs of substantially rectangular outline shape, so that in operation a rectangular hole is dug. <IMAGE>

Description

SPECIFICATION Digging apparatus This invention relates to digging apparatus and has as its main object to provide such an apparatus for rapidly digging substantially rectangular holes having substantially vertical side walls. Such box-like holes, which are hereinafter referred to simply as rectangular, are particularly required for military purposes, as weapon pits or so-called "fox-holes" to accommodate and protect one or more soldiers standing upright, but it should be clearly understood that the scope of the invention is in no way restricted to the digging of holes for any particular purpose.

Viewed from one aspect the invention provides apparatus for digging rectangular holes, comprising a supporting structure for resting on the ground, and power-driven recirculatory digging means mounted on said supporting structure for up and down movement, the effective digging area of said digging means in operation comprising substantially only a substantially horizontal bottom run or runs of substantially rectangular outline shape, so that in operation a rectangular hole is dug.

The said digging means may comprise a single recirculatory digger or, as is preferred, a plurality of such diggers which cooperate to dig a rectangular hole. In one form of the invention the apparatus has four such diggers cooperating in pairs, with one such pair mounted on each side of a central structural mounting plate carrying guide members and driving mechanism for endless carriers of the respective recircu latory diggers.

Preferably the or each said digger of the digging means comprises an endless carrier, such as a belt or chains, carrying a series of digging elements, preferably interspersed with buckets for conveying away the spoil. The digging elements may comprise toothed scrapers for example.

Preferably the apparatus includes means for driving the digging means down into the ground relative to the said supporting structure, although this may not be essential if the digging means is heavy enough to operate under its own weight.

However it is of course essential to provide means, not necessarily but preferably powered, for tifting the digging means out of the ground when a hole is finished.

Preferably the said supporting structure is mobile, being provided with wheels, tracks or other means for moving it over the ground, although it could conceivably be a stationary structure adapted to be placed at and subsequently removed from the intended location of each hole, e.g. by suitable transporting means such as a mobile crane. Preferably the supporting structure is a powered vehicle, akin to a tractor, although alternatively it could be adapted to be towed over the ground and if necessary be powered from another vehicle or other power unit.

Preferably the digging means is mounted for up and down movement in a space defined entirely within the body of the supporting structure, preferably substantially centrally thereof for maximum stability.

The apparatus may incorporate means for use in disposing of spoil, for example in the form of one or more conveyors associated with the digging means and leading to a suitable receptacle, removably linked to the digging apparatus, for example a wheeled or tracked skip preferably dimensioned to accommodate all of the spoil from at least one hole.

The apparatus may incorporate means for varying the direction of the up and down movement of the digging means relative to the said supporting structure so as still to enable a hole to be dug with vertical side walls when the supporting structure is resting on sloping ground.

An embodiment of the invention will now be described by way of example and with reference to the accompanying drawings, in which: Figure 1 is a side view of a known ditch-digging machine; Figures 2 and 3 are diagrammatic side and end views of'a digging apparatus according to the invention, with the digging means shown separately form the supporting structure; Figure 4 is a diagrammatic side view of the apparatus of Figures 2 and 3, showing the digging means in use; Figure 5 is a perspective view of the apparatus with the digging means removed; Figure 6 is a more detailed perspective view of the digging means itself; and Figure 7 is a perspective view of the whole apparatus together with a spoil skip.

Referring first to Figure 1, this known ditchdigging machine is illustrated in order to clarify the shortcomings of such machines so far as concerns the digging or rectangular holes, of which the principal one is that the hole produced, despite having a substantially vertical end wall 1 and side walls, and indeed a horizontal bottom if the hole is continued to the right as shown in the drawing, cannot avoid having its other end wall sloping at a relatively shallow angle as at 2. Thus this machine is not able to dig a rectangular hole as hereinbefore defined.

Referring now particularly to Figures 2 to 5, a digging apparatus according to the invention comprises a supporting structure in the form of a tractor 3 movable over the ground on endless tracks 4 and powered by an internal combustion engine 5 which also powers both the up and down movement and the recirculatory movement of the digging means, via suitable hydraulic motors for example. The body of the tractor defines a substantially central open rectangular space 6, extending right through such body from top to bottom, for the reception of digging means 7 to be described in detail below with particular reference to Figure 6. The digging means 7 comprises two pairs of cooperating recirculatory diggers mounted on a central structural mounting plate 8 whose fore and aft vertical edges are received for up and down movement in two vertical channel members 9 of the tractor 3.A protective shroud 10 is mounted on top of the plate 8. Means, not shown, are provided for powering the digging means down into the ground (as shown in Figure 4) to dig a hole, and for lifting it out again. Such means could for example comprise pin ions on the tractor driving ratchets on the fore and aft edges of the mounting plate 8 and powered by hydraulic means as already mentioned.

Referring now particularly to Figure 6, the mounting plate 8 carries four separate diggers 11 making up the digging means 7. Each digger 11 comprises a series of alternate digging elements or scrapers 12 and spoil removing buckets 13, mounted on a pair of endless chains 14. The chains extend around cylindrical members mounted in cantilever fashion from the mounting plate 8. One of the two bottom cylinders, 1 5, is a drive roiler for the chain 14, whilst the top (stationary) cylinder 1 6 has an aperture 1 7 therein to receive the spoil from the buckets 1 3 as the latter are inverted upon passing over the cylinder.

Inside the cylinder 16, and extending beyond it as shown, is an archimedean-screw conveyor 1 8 which transports the spoil laterally and deposits it on an endless conveyor 1 9 (Figure 7) for delivery to a spoil skip 20. The cylinders supporting the chains 14 of each of the four diggers 11 are coaxial with, and share a common mounting and drive with, corresponding cylinders of the digger on the opposite side of the mounting plate.

The diggers 11 circulate in the directions shown, i.e. all of them inwardly at the bottom, so that the spoil is carried up the central passage between the adjacent vertical runs of the pair of cooperating diggers on each side of the mounting plate, being retained in the buckets 1 3 during such vertical movement by stationary backing plates 21.

It will be seen that the digging means 7 comprising the four diggers 11 firstly has its bottom, i.e. digging, runs horizontal so as to form a flat-bottomed hole, and secondly has those bottom runs, which constitute substantially the whole of its effective digging area, so arranged as together to define a substantially rectangular outline shape whereby to form a hole of rectangular shape in plan, with vertical side walls.

Thus the invention, at least in its preferred and illustrated embodiment, provides a simple, efficient and rugged apparatus for digging rectangular holes in rapid succession at selected locations, and for simultaneously enabling the substantial amounts of spoil so produced to be quickly and efficiently disposed of.

Claims (14)

1. Apparatus for digging rectangular holes, comprising a supporting structure for resting on the ground and power-driven recirculatory digging means mounted on said supporting structure for up and down movement, the effective digging area of said digging means in operation comprising substantially only a substantially horizontal bottom run or runs of substantially rectangular outline shape, so that in operation a rectangular hole is dug.

2. Apparatus as claimed in claim 1 ,wherein said digging means comprises a plurality of recirculatory digger assemblies.

3.Apparatus as claimed in claim 2, comprising four such digger assemblies co-operating in respective pairs, one such pair being mounted on each side of a central structural mounting plate mounted on said support structure for up and down movement as aforesaid.

4. Apparatus as claimed in claim 3, wherein each of said digger assemblies comprises an endless carrier carrying a series of digging elements, and said mounting plate carries guide members and a driving mechanism for said endless carriers.

5. Apparatus as claimed in claim 4, wherein said series of digging elements of each digger assembly is interspersed with buckets for conveying away the spoil.

6. Apparatus as claimed in any of the preceding claims, including means for disposing of spoil comprising one or more conveyors associated with the said digging means.

7. Apparatus as claimed in claims 5 and 6, wherein a said guide member for each said digger assembly comprises a stationary hollow cylinder having an aperture for receiving spoil from the said buckets and housing an archimedian screw conveyor for transporting said spoil.

8. Apparatus as claimed in claim 7, wherein each pair of digger assemblies on the respective sides of said mounting plate co-operate to carry spoil up a central space between them.

9. Apparatus as claimed in claim 8, including a stationary backing plate associated with each said digger assembly for retaining the spoil in said central space during its transportation.

1 0. Apparatus as claimed in any of the preceding claims, having means for driving said digging means both upwards and downwards relative to said supporting structure.

11. Apparatus as claimed in any of the preceding claims, wherein said digging means is mounted for up and down movement in a space defined by and extending through the body of the supporting structure.

12. Apparatus as claimed in any of the preceding claims, wherein said supporting structure is mobile, being provided with wheels, tracks or other means for moving it over the ground.

13. Apparatus according to claim 12, which is power-driven for movement over the ground.

14. Apparatus as claimed in any of the preceding claims, including means for varying the direction of the up and down movement of the digging means relative to the said supporting structure.

1 5. Apparatus for digging rectangular holes, substantially as hereinbefore described with reference to the accompanying drawings.