GB2130063A

GB2130063A - Machine for laying sheet material

Info

Publication number: GB2130063A
Application number: GB08230597A
Authority: GB
Inventors: Martin Bailey; Peter Waring
Original assignee: WARING Ltd PETER
Current assignee: WARING Ltd PETER
Priority date: 1982-10-26
Filing date: 1982-10-26
Publication date: 1984-05-31
Also published as: GB2130063B

Abstract

A machine for laying sheet material over an area of land, e.g. used in growing crops, includes means for perforating the sheet material as it is laid, comprising one or more rotating discs (30), each disc having a sharp edge protruding radially outwardly beyond its circumference. The sharp edge is suitably provided by the edge of one or more sharp knives (32) which are adjustably mounted on each disc. <IMAGE>

Description

SPECIFICATION Machine for laying sheet material This invention relates to the laying of flexible material over land areas, and is especially concerned with the provision of a novel device for laying flexible material in strip form over an area of land.

Piastics films, for example polyethylene films, are finding increased use in agriculture and horticulture as soil coverings, with a view to increasing crop yield and improving plant growth.

Opaque and translucent films are used as a "mulch", reducing weed competition and thereby improving the crop. Transparent films laid over a sown or growing crop raise soil temperature and aid plant growth, generally producing an earlier and consequently more valuable crop. In addition, any impermeable film laid over soil reduces the loss of water by evaporation and therefore reduces the quantity of water required to produce the crop.

Plastics films are commercially available for most, if not all, of these applications.

The "greenhouse" effect produced by laying a film over sown or planted soil is highly beneficial, but siffers the disadvantage that as the crop grows either the film is stretched, until it is finally ruptured by the rising crop, or the film does not "give" and therefore damages the crop. "Slack" may be put into the film at the time of laying, which can be taken up by crop growth, a device for doing which is described in our U.K. Patent No: 1,504, 967. Film may be laid with perforations which will allow a crop to respire and develop underneath, or with perforations through which the crop will grow. Both types of film may be degradable in a relatively short predictable time or may be relatively resistant to degradation and thus need removal.

The use of perforated film is carried out in one of two ways. In the first the film is perforated as part of the manufacturing process, and is supplied to the user in the form of a roll of perforated film.

In the second, the actual film-laying machine is provided with perforating devices which puncture the laid film and, optionally, at the same time make a small hole in the soil and deposit a seed in the hole.

The main disadvantage of the use of pre-perforated film is that it is expensive; the perforating of laid film, with or without the simultaneous sowing of seeds through the formed holes, involves the use of bulky and complex machinery. In the Specification of our Patent No: 2,055,534 we have described a machine which reduces the expense and complexity involved in the use of perforated plastics films. In that Specification we have described a machine for laying sheet material on the ground comprising a support frame, a roll of sheet material rotatably supported on the support frame, means for causing the marginal edges of the sheet material to be temporarily retained in or on the ground, and means for perforating the sheet material as it is wound from the roll thereof and before it is placed in contact with the ground.In one embodiment described in Patent Specification 2,055,534 the perforating means comprises two opposed rollers, between which the unperforated film is fed, one roller having spaced projections and the other having a surface upon which the projections act.

In another embodiment, the means for perforating the film comprises a rotatable roller provided on its cylindrical surface with a series of spaced knife edges, each of which provides a slit on contacting the film.

In accordance with the present invention the means for perforating the sheet material comprises one or more rotating discs, the or each disc having a sharp edge protruding radially outwardly beyond its circumference.

Preferably the disc or discs are mounted on a motor-driven shaft, with one, two or more discs mounted on one motor driven shaft, the drive motor itself being adjustably mounted on the support frame. The distance of the disc from the plastics film, and the inclination of the disc with respect to the film are preferably adjustable, in order that the position of the perforations on the film, and their inclination, may be adjusted. The cutting edges may be the edges of sharp knives attached to the discs. The speed of rotation of the discs, and the number of cutting edges on each disc, determines the distance between adjacent perforations or slits in the plastics film material.

The size of the slits is dependent upon the length of the sharp edge or edges and the radius of the discs. By adjustably mounting the knife or knives on the discs, it is possible to use a single disc for producing slits of different lengths.

The invention is now illustrated by means of the accompanying diagrammatic drawings, in which: Figure 1 is a perspective view of machinery for perforating and laying film incorporating the perforating means of the invention; and Figure 2 is a sketch showing three lengths of film having perforations produced by the machine of Figure 1.

Referring to Figure 1, there is shown a machine similar to that depicted in Figure 4 of our Patent Specification No: 2,055,534. It comprises a frame 10, suitably of welded angle iron, on which is mounted a connecting link 12 for attachment to a tractor or other motorised machine. Mounted on each side of frame 10 is an upstanding arm 14, the upper ends of which receive and rotatably support the shaft of a stock roll 1 6 of, for example, unperforated polythene sheet. Downwardly depending arms 1 8 are also mounted on frame 10, and support between them a freely rotatable or non rotatable rod 20. A similar rod, 22, is mounted in brackets 24 welded to the frame 10.

Also mounted on the frame 10, and parallel with rods 20 and 22, is a bar 26. Bar 26 is provided with a series of spaced through-holes 28.

Discs 30 carrying radially-adjustable knives 32 are mounted on shafts 34 of motors 36. The motors 36 may be eiectric or hydraulic motors, or may be driven from the tractor or the land wheels, for example. The motors 36 are mounted on the bar 26 by means of mounting brackets 38, the positions of which along bar 26 are adjustable by means of extension bolts entering through-holes 28. The position of discs 30 with respect to the film of plastics material 40 may be adjusted by movement of the motor 36 along bracket 38, or adjustment of the position of the bar 26 on the frame 10. Similarly, the angular disposition of the discs 30 may be adjusted by rotating the brackets 38 with respect to the bar 26.

The machinery is completed by means of stabilising wheels or compacting rollers 42, and soil moving blades 44.

In operation, plastics film from stock roll 1 6 is trained around rods 22 and 20 and then onto the ground, whereon it is pressed by rollers 42 and on to the marginal edges of which soil is swept by blades 44. During the passage of the plastics film between rods 22 and 20, a series of slits 46 is produced by means of the knife edges 32 on rotating discs 30.

Figure 2 illustrates different formations of slits, formed by rotating brackets 38 a few degrees about their axes, and then re-locking them to bar 26.

Further details of the manner in which the machinery may be used in the growing of crops are given in the Specification of our Patent 2,055,534.

Claims

1. A machine for laying sheet material which includes means for perforating the sheet material comprising one or more rotating discs, the or each disc having a sharp edge protruding radially outwardly beyond its circumference.

2. A machine for laying sheet material according to claim 1 in which the disc or discs are mounted on a motor-driven shaft, one or more discs being mounted on one motor driven shaft.

3. A machine for laying sheet material according to claim 2 in which the drive motor is adjustably mounted on the support frame.

4. A machine for laying sheet material according to any preceding claim in which the distance of the disc or discs from the sheet material is adjustable.

5. A machine for laying sheet material according to any preceding claim in which the inclination of the disc or discs to the sheet material is adjustable.

6. A machine for laying sheet material according to any preceding claim in which the speed of rotation of the disc or discs is variable.

7. A machine for laying sheet material according to any preceding claim in which the sharp edge of each disc is provided by the edge of one or more sharp knives attached to the disc.

8. A machine for laying sheet material according to claim 7 in which the knife or knives are adjustably mounted on each disc.

9. A machine for laying sheet material according to any preceding claim in which the sheet material is plastics film.

10. A machine for laying sheet material substantially as hereinbefore described and with reference to the drawings.