GB1581967A

GB1581967A - Blinds

Info

Publication number: GB1581967A
Application number: GB6542/78A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1978-02-18
Filing date: 1978-02-18
Publication date: 1980-12-31

Description

(54) IMPROVEMENTS IN OR RELATING TO BLINDS (71) I, CHARLES ROBIN DOUGLAS, of Robin's Acre, Mill Road, Maxey, Nr. Peterborough, Northants, a British Subject, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is. to be performed, to be particularly described in and by the following statement: - This invention relates to blinds and has particular application to glasshouses.

My co-pending U.K. Patent Application No. 19203/74 (Serial No. 1,501,615, hereafter the "parent application"), describes and claims a blind suitable for covering crops in a glasshouse, comprising an elongated sheet of opaque flexible material, a lateral support member of elongated form attached to and extending along one end of the.sheet, means anchoring the other end of the' sheet, a plurality of longitudinal support members extending lengthwise of the sheet and in substantially parallel array so as to slidably support the lateral support member and the sheet, and conveyor means; including conveyor cables, for- moving the lateral support member lengthwise relative to ,.the longitudinal support members .50- as to extend or reduce the effective length' of the sheet.

The present invention resides in the sub-.

stitution of a non- or partially opaque' flexible sheet.

According to the present invention, a blind for covering .'crops in a glasshouse comprises an elongated sheet of non- or partially opaque flexible material, a lateral support member 'of elongated form attached to and extending laterally along one end of the' sheet, me'anus anchoring the other end of the sheet, a plurality of longitudinal support members extending lengthwise of the sheet and in substantially parallel array so a,s' to slidåbly support the elongated support member and the sheet, and conveyor means, including conveyor cables, for moving the lateral support member lengthwise relative to the longitudinal support mem- bers so às to. extend or reduce the effective length of the sheet, and means for.yield- ably clamping the conveyor cables to the lateral support member.

The lateral support member is preferably loosely suspended from (or supported by the upper surface of), the longitudinal sup.

port member; the conveyor means preferably comprises cables attached to the lateral support member and means for winding the cables in opposite directions; and the cables are preferably endless.

As in the case of the parent application, the present invention is particularly applic able to glasshouses wherein the floor space is covered with obstructions such as up right roof supports and heating pipes,"which may be disposed irregularly about the floor.

To overcome such obstructions, several blinds are used and each conveyor means may be constructed so as to allow its cable to move whilst allowing the elongated support member to remain stationary, movement of the elongated support member being prevented by contact with an obstruction. This "slip" may be 'provided by means yieldably clamping the conveyor cable to the support member, and bperable when a friction force of predetermined level has been overcome.

An embodiment of the present invention will now be described. by way bf exampli: with reference to the accompanying drawings, wherein: ' Figure 1 is a side view in'section of a glasshouse, Figure' 2 is a. fragmentary plan view; taken on the lines II-II of Figure 1, Figures 3 and 4 are views, to an enlarged scale, looking in the'directions of the arrows -III and IV of Figures 2 and 3, Figure 5 is a view, in perspective, of modified conveyor means, and Figure 6 'is an "exploded" view of a modified clutch.

In the figures, which correspond to tliose accompanying the parent application,.like reference numerals refer .to.' like .com ponents.

With reference to Figures 1 to 4, each of a plurality of sidelby-side disposed blinds 1 for covering crops' (not shown) in a multi roofed glasshouse 2 comprises an elongated sheet 3 of non- or partially opaque flexible material. The material of sheet 3 may, for example, be of polyethylene, which is either fully transparent or which will provide partial shade to a crop, i.e. one allowing only a percentage of the available light to penetrate to the crops. For example, up to 60% light transmission. A lateral support member of elongated form comprising a wooden batten 4 is attached to one end of the sheet 3 by means of pins 5 (Figure 3), the other end of the sheet 3 being attached, i.e. anchored at 6 (in a light-tight manner), to the adjacent edge of the next sheet in the closed position.A plurality of longitudinal support members (wires 7) extend lengthwise of the sheets 3 and in substantially parallel array from wall to wall of the greenhouse. Staples 8 are carried .by the batten 4 for loosely suspending the batten and hence the sheet 3 from the support wires 7, and conveyor means, including endless conveyor cables comprising ropes 9, are provided for moving the laterally-extending batten 4 relative to the longitudinally-extending support wires 7 so as to extend or reduce the effective length of the sheet 3.

In further detail, the roof of the glasshouse 2 is of saw-tooth form and is supported by a plurality of upright purlins 10.

The presence of the purlins and other obstructions (not shown), prevent the use of a single blind 1. As shown in Figure 3, the purlins carry support wires 15 mounted on brackets 16, which wires support the anchored "trailing" edges of the sheets 3.

The conveyor ropes g are disposed in rows substantially parallel to the wires 7 and are supported by pulleys 17 (Figure 2) carried by the end walls of the glasshouse 2.

Opposite ends of the wires 7 are attached to said end walls. Each endless rope 9 is wrapped several times around a tubular drive shaft 18 (Figure 3) which extends between and is supported from the structure of the glasshouse and is rotatable in either direction by a reversible electric motor 37 and gear box unit and control box 36. (See Figure 5.) 'As best shown in Figure 4, each rope 9 is yieldably clamped to the battens 4 by clutch means, each comprising a metal clamping plate 19 held in place by tensioning nuts 27 and bolts 20. Rubber washers 26 are interposed between the metal plate and the nuts 27 whereby the plate 19 is urged, in a resilient manner, towards the batten 4.The rope 9 is not clamped tight; the nuts being adjusted so as to allow the rope to overcome frictional forces and to "slip", when, as shown in Figure 3, movement of the batten 4 (by rope 9), is arrested by contact with a purlin 10, and frictional forces between the rope 9, batten 4 and plate 19 are overcome.

In operation, with all the blinds 1 in the closed position, in order to expose the crops to direct sunlight, the shaft 18 is rotated to pull the battens 4 and hence the sheets 3 over the whole area of the glasshouse 2.

As the battens 4 slide along the support wires 7, some of the battens are obstructed by purlins 10 or other structure. However, the clutch means of the obstructed battens yield whereby the associated ropes 9 "slip".

Thus the remaining battens 4 are allowed to continue their movement until they in turn meet obstructions.

Opening of the blinds 1 is thus automatically and quickly achieved.

When the crops beneath the blinds are required to be covered, the shaft 18 is rotated in the opposite direction, whereupon the battens 4 are "retracted" away from their obstructions and the sheets 3 unfolded.

Figures 5 and 6 illustrate modifications.

With reference first to Figure 5, the sheet 3 is attached to an elongated support member 4a comprising a metal tube. The tube 4a is supported by the wires 7 (not shown in Figure 5) as before, and the "leading edge" of the sheet 3 is attached to the tube 4a by simple clips 35. The drive shaft 18 is rotated by the gear/control box unit 36 driven by the reversible electric motor 37 by way of a flexible "V"-belt 38. The shaft 18 is rotatably supported in bearings 39.

In this modification, the ends of the ropes 8 are secured to the shaft 18 by "JUBILEE" (R.T.M.) clips 40 and the ropes are guided over double pulleys 41 and single pulleys 42.

The modified arrangement of Figure 5 employs modified clutch means best shown in Figure 6. With reference to Figure 6, in this modification, the clamping plate 19a is held in place by "U"-bolts 45 mounted on the tube 4a. The "U"-bolts 45 are clamped to the tube 4a by a clamping plate 46 and nuts 47, and the plate 19a is resiliently urged against the rope 9 by nuts 27a, metal washers 48 and rubber washers 26a.

In addition to controlling the periods of direct sunlight to which the crops are exposed, the blinds (which are disposed at any convenient height above the ground) serve to conserve heat, acting as heat barriers and confining any heat at ground level to beneath the level of the blinds.

To further assist the function of the blinds 1, the sides of the glasshouse 2 may be provided with roller blinds 25 (Figure 1), or any other suitable covers which are removable.

The blinds can differ in length (as seen in Figure 2), and in width also.

The elongated support members 4, 4a, which can comprise metal strips, may be placed on top of the support wires 7 so as to be directly supported thereby.

The pins 5 may be replaced by clips.

WHAT I CLAIM IS: - 1. A blind for covering crops in a glasshouse, comprising an elongated sheet of non- or partially opaque flexible material, a lateral support member of elongated form attached to and extending laterally along one end of the sheet, means anchoring the other end of the sheet, a plurality of longitudinal support members extending lengthwise of the sheet and in substantially parallel array so as to slidably support the elongated support member and the sheet, and conveyors means, including conveyor cables, for moving the lateral support member lengthwise relative to the longitudinal support members so as to extend or reduce the effective length of the sheet, and means for yieldably clamping the conveyor cables to the lateral support member.

2. A blind as claimed in Claim 1, wherein the lateral support member is loosely suspended from the longitudinal support members.

3. A blind as claimed in Claim 1, wherein the lateral support member is disposed on top of the longitudinal support members.

4. A blind as claimed in Claim 1, 2 or 3, which has a light transmission of up to 60%.

5. A blind as claimed in any one of Claims 1 to 4, wherein the conveyor means comprise cables attached to the elongated support member and means for winding the cables in opposite directions.

6. A blind as claimed in any one of Claims 1 to 5, wherein the clamping means comprise a clamping plate and means for resiliently urging the plate towards the lateral support member.

7. A blind as claimed in any one of Claims 1 to 6, wherein the cables are wound round a drive shaft whereby rotation of the shaft causes movement of the cables.

8. A blind as claimed in any one of Claims 1 to 7, wherein the longitudinal support members comprise wires.

9. A glasshouse provided with at least one blind as claimed in any one of Claims 1 to 8.

10. A blind as claimed in Claim 1, substantially as hereinbefore described with reference to Figures 1 to 4 of the accompanying drawings.

11. A blind as claimed in Claim 1, substantially as hereinbefore described with reference to Figures 1 to 4 of the accompanying drawings, modified substantially as hereinbefore described with reference to Figures 5 and 6 of said drawings.

12. A glasshouse, provided with a blind as claimed in Claim 10.

13. A glasshouse, provided with a blind as claimed in Claim 11.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. The blinds can differ in length (as seen in Figure 2), and in width also. The elongated support members 4, 4a, which can comprise metal strips, may be placed on top of the support wires 7 so as to be directly supported thereby. The pins 5 may be replaced by clips. WHAT I CLAIM IS: -

1. A blind for covering crops in a glasshouse, comprising an elongated sheet of non- or partially opaque flexible material, a lateral support member of elongated form attached to and extending laterally along one end of the sheet, means anchoring the other end of the sheet, a plurality of longitudinal support members extending lengthwise of the sheet and in substantially parallel array so as to slidably support the elongated support member and the sheet, and conveyors means, including conveyor cables, for moving the lateral support member lengthwise relative to the longitudinal support members so as to extend or reduce the effective length of the sheet, and means for yieldably clamping the conveyor cables to the lateral support member.

12. A glasshouse, provided with a blind as claimed in Claim 10.

13. A glasshouse, provided with a blind as claimed in Claim 11.