WO2004036977A1

WO2004036977A1 - Polytunnel system

Info

Publication number: WO2004036977A1
Application number: PCT/GB2003/004530
Authority: WO
Inventors: Thomas Robert Corbett
Original assignee: Haygrove Limited
Priority date: 2002-10-26
Filing date: 2003-10-20
Publication date: 2004-05-06
Also published as: GB2394485A; GB0324404D0; AU2003274338A1; GB0225092D0

Abstract

A polytunnel system comprising a plurality of polytunnel supports (10, 12) and track member (22) interconnecting at least some of the supports (10, 12). The system may be used as part of a coveyor for use in the transportation of items along a polytunnel. Alternatively it may be used to drive, for example, a vent adjustment system.

Description

POLYTUNNEL SYSTEM

The invention relates to a polytunnel system for use in the cultivation of

crops, for example strawberries.

The use of polytunnels to provide better, more easily controllable and more

consistent growing conditions is becoming increasingly common. However, it has

been found that the cultivation of crops in polytunnels tends to be relatively labour

intensive. It is an object of the invention to provide a polytunnel system whereby

the completion of certain tasks can be automated. For example,, the transportation

of produce and/or tools into or through the tunnel may be automated. Further,

venting of the tunnel by raising the sides thereof, for example to control the

temperature within the tunnel or to protect the tunnel structures during high wind

conditions.

Co-Pending British Patent Application No.0210091.5 describes apolytunnel

system having an end frame which is sufficiently rigid that it can carry drive means

for use in operating a range of pieces of machinery. The end frame also permits a

common drive means to be used to operate machinery in a number of adjacent

polytunnels.

According to one aspect of the invention there is provided a polytunnel

system comprising a plurality of polytunnel supports, and a conveyor track member interconnecting at least some of the polytunnel supports.

The conveyor track member is conveniently of substantially rigid form,

improving the structural integrity of the polytunnel.

Typically a polytunnel includes two parallel rows of leg members, each leg

member of one row being connected to a leg member of an adjacent row by means

of a hoop member such that the leg members support the hoop member. In such an

arrangement, the conveyor track member conveniently interconnects the hoop

members.

The conveyor track member may be designed to allow one or more carriers

to be moved along the polytunnel, for example to assist in the transport of products

into or out of the tunnel. In such an arrangement, a cable is conveniently provided

to move the or each carrier, the cable being driven, for example, by drive means

located at an end of the polytunnel.

Alternatively, the conveyor track member may be designed to allow a control

member to be moved along the polytunnel, the control member being moveable, for

example, to drive parts of the tunnel wall between vented and closed positions.

Again, the control member may be arranged to be cable driven, and if desired the

carrier member of a transportation system may be designed to also act as the control

member. In one embodiment of such an arrangement the tunnel system is provided

with an elongate venting bar of flexible form, the venting bar being connected to a

covering of the polytunnel, a runner being arranged to ride along the venting bar

under the control of the control member. In use, the length of an adjustable link

between the control member and the runner is selected and the runner is pulled

through the tunnel by the control member to lift the flexible venting bar, and hence

the covering, to provide a chosen degree of venting. A reduction in venting is

achieved by pulling the runner through the tunnel to force the venting bar, and hence

the covering, downwards, and this is achieved by lowering the point on the control

member to which the link is connected.

Although two specific uses of the conveyor track member are mentioned

above, it will be appreciated that a number of other operations may make use of the

conveyor track member.

The invention will further be described, by way of example, with reference

to the accompanying drawings, in which:

Figure 1 is a diagrammatic sectional view of a tunnel;

Figure 2 is a side view of the tunnel shown in Figure 1;

Figures 3, 4 and 5 are views illustrating parts of the tunnel of Figures 1 and 2;

and Figure 6 is an enlarged view, illustrating part of a venting arrangement.

The polytunnel illustrated in the accompanying drawings is, for the mostpart,

of conventional form comprising a number of leg members 10 arranged in two

parallel rows, each leg member 10 of one ofthe rows being inter-connected with a

corresponding leg member 10 of another of the rows by means of a hoop member

12. A polythene or other plastics material cover is stretched over the hoop members

12 and leg members 10 to form an enclosed tunnel forming a growing space within

which crops may be cultivated. A wide range of crops may be grown in the

polytunnel. As shown in Figure 1, an end frame 16 is formed to provide additional

rigidity to the end ofthe polytunnel. The end frame is ofthe form described in the

co-pending Patent Application No. 0210091.5. As shown in Figures 2 and 3, the

end frame 16 supports amotor 18 of any suitable form, the motor 18 driving a pulley

20.

In accordance with the invention, the hoop members 12 are inter-connected

by a substantially rigid conveyor trackmember 22 which extends along substantially

the full length ofthe polytunnel. The conveyor track member 22 is located beneath

the peak of each hoop member 12 so as to minimise the obstruction to head room

within the polytunnel, thereby minimising any obstruction to the movement of

machinery through the tunnel. The conveyor track member 22 includes flanges upon which the wheels 24

of a carrier member 26 can ride to permit the carrier member 26 to be transported

along substantially the full length of the conveyor track member 22. It will be

appreciated that the conveyor track member 22 is of relatively large length in order

to extend along substantially the full length of the polytunnel. Clearly, it may

therefore be desirable to construct the conveyor track member 22 in several parts

which are inter-connected in an end-to-end fashion, in use. Where the conveyor

track member 22 is made in several parts, the inter-connection between the various

parts ofthe conveyor track member should be such as to permit the carrier member

26 to move freely between the various parts ofthe conveyor track member.

The carrier member 26 is connected to cables which extend along the length

ofthe conveyor track member and around the pulley 20 and around another pulley

located at the opposite end ofthe conveyor track member 22. It will be appreciated

that with such an arrangement, rotation of the pulley 20 by the motor 18 causes

movement of the cable to draw the carrier member 26 along the conveyor track

member 22. The direction of movement ofthe carrier member 26 will depend upon

the direction of rotary movement ofthe pulley 20.

Where the carrier member 26 is to be used as part of a system for use in the

transportation of products or tools to or out of the polytunnel, then the carrier member 26 may have, depending therefrom, a basket or tray arranged such that as

the motor 18 drives the carrier member 26 along the conveyor track member 22, the

tray or basket is moved through the polytunnel. Generally, the tray or basket will

be suspended from the carrier member 26, thus it will be appreciated that the weight

of the tray or basket and any products or tools carried thereon is supported by the

conveyor track member 22. However arrangements may be possible in which the

carrier member 26 is used to pull a wheeled or tracked vehicle along the polytunnel,

for example for use in the transportation of products or tools into or out of the

polytunnel.

Although the carrier member 26 may be used in the transportation of products

or tools along the polytunnel, in the arrangement shown in the accompanying

drawings the carrier member 26 is used as a control member for use in the operation

of an automated venting system for the polytunnel. As shown in Figure 4, the

carrier member 26 is connected to a rigid link bar 28 of adjustable length, the

opposite end of which is connected to a runner device 30 which is slidable along a

flexible venting bar 32 which extends substantially the full length ofthe polytunnel.

The runner 30 is provided with a plurality of wheels adapted to ride along surfaces

ofthe bar 32 such that the runner 30 is freely slidable along the bar 32.

As shown in Figure 6, each hoop member 12 carries a slidable grip member 40 to which the polythene or other material cover 14 is secured. Each grip member

40 is secured, for example by means of a wire link 42, to the bar 32. It will be

appreciated, therefore, that raising or lowering of the bar 32 causes each grip

member 40 to move along its respective hoop member 12 thereby raising or lowering

the cover 14 to increase or reduce ventilation ofthe tunnel.

In use, if it is desired to increase the ventilation of a tunnel, the link bar 28

is shortened. The carrier member 26 is then drawn though the tunnel using the

motor 18 in the usual manner. The action of drawing the carrier member 26 through

the tunnel pulls the runner 30 through the tunnel, the runner 30 causing the flexible

venting bar 32 to be lifted to a position determined by the length ofthe link bar 28.

In the attached drawings, the polytunnel is shown with the carrier member 26 and

runner 30 only part-way along the polytunnel with the result that venting has been

increased in one part ofthe tunnel, but has not yet been increased elsewhere.

A plurality of ropes (not shown) are provided in a zig-zag configuration to

hold the cover 14 in place. When the sides ofthe tunnel have been lifted, friction

between the ropes and the cover 14 results in the cover 14 being held in the desired

position once the passage ofthe runner 30 through the tunnel has been completed.

To lower the cover 14 to reduce ventilation, the point at which the link bar

28 is connected to the carrier member 26 is lowered and the carrier member 26 and runner 30 drawn through the tunnel thereby forcing the vent bar 32 and cover 14

downwards.

Although in the description hereinbefore venting of only one side of the

tunnel is adjusted, ventilation ofthe other side can be adjusted in the same manner

either simultaneously with one another, or separately. Controlling the ventilation

of both sides ofthe tunnel simultaneously is advantageous in that the side-acting

forces on the carrier member 26 are balanced or substantially balanced.

Claims

1. A polytunnel system comprising a plurality of polytunnel supports, and a

track member interconnecting at least some ofthe supports.

2. A system according to Claim 1, wherein the track member is of substantially

rigid form.

3. A system according to Claim 1 or Claim 2, wherein at least one of the

supports comprises a pair of leg members and a hoop member supported by the leg

members, the track member being carried by the hoop member.

4. A system according to any one ofthe preceding claims, further comprising

a carrier member moveable along the track member and drive means for driving the

carrier member.

5. A system according to Claim 4, wherein the drive means comprises a cable

connected to the carrier member and co-operating with a motor driven pulley.

6. A system according to Claim 4 of Claim 5, further comprising load

supporting means associated with the carrier member.

7. A system according to Claim 6, wherein the load supporting means comprises

a basket or tray carried by the carrier member.

8. A system accordingto Claim 6, wherein the load supporting means comprises

a vehicle connected to and arranged to be driven by the carrier member.

9. A system according to any of Claims 1 to 3, further comprising a control

member arranged to be driven along the track member, and drive means for driving

the control member.

10. A system according to Claim 9, wherein movement ofthe control member

drives parts of a wall of the tunnel between raised and lowered positions.

11. A system according to Claim 10, further comprising an elongate venting bar

of flexible form, the venting bar being connected to a covering ofthe polytunnel, a

runner being arranged to ride along the venting bar under the control ofthe control

member.

12. A system according to Claim 11, further comprising a link of adjustable

length interconnecting the runner and the control member.

13. A polytunnel system substantially as hereinbefore described with reference

to any of the accompanying drawings.