GB2258805A

GB2258805A - A curtain tensioner

Info

Publication number: GB2258805A
Application number: GB9217641A
Authority: GB
Inventors: John David Church
Original assignee: SEAKA PROD Ltd
Current assignee: SEAKA PROD Ltd
Priority date: 1991-08-20
Filing date: 1992-08-19
Publication date: 1993-02-24
Anticipated expiration: 2012-08-19
Also published as: NZ239486A; GB2258805A8; GB9217641D0; AU665201B2; AU2080792A; GB2258805B

Abstract

A curtain tensioner (suitable for tensioning the curtains fitted to a motor vehicle such as a truck) is of one-handed operation and includes a handle coupled to a tensioning means adapted to be coupled to a roller holding a curtain. Rotation of the handle imparts tension to the roller. Extreme rotation of the handle releases the tension. <IMAGE>

Description

This invention relates to a curtain tensioner: and is applicable particularly, but not exclusively to a curtain tensioner for tensioning and releasing the tension of side curtains as used in vehicles such as trucks, trailers, railway wagons or the like.

Side curtains are widely used to form part of an enclosure of the load-carrying space of such vehicles.

Typically, each curtain is suspended along the top thereof on a form of track, along which the curtain can travel for opening and closing purposes. One upright edge of the curtain is fixed and the other upright edge is releasably fastened to an elongate roller, of which the axis of rotation is vertical.

The roller normally remains attached to the relevant upright edge of the curtain and may travel along therewith as the curtain is opened and closed.

When the curtain is to be closed, the roller then rotates about said axis to wind surplus curtain onto the roller until the curtain is put into substantial tension, to reduce flapping of the curtain.

The rotation of the roller is effected by a curtain tensioner, from which the roller is optionally detachable.

The curtain tensioner is normally permanently attached to the vehicle, at the base of the roller when the latter is in the curtain-tensioning location.

According to a broad aspect, the invention, provides a curtain tensioner, comprising a body adapted for mounting to a vehicle, said body mounting a rotatable member adapted to be engageable with a curtain roller 8o that, when engaged thereto, rotation of the member causes corresponding rotation of the roller, a rotatable handle means operable by an operator, means interconnecting the handle and said member such that rotation of the handle in one direction of rotation imparts rotation of the member in a first direction to tension the curtain, and disengageable anti-rotation means operable on said member to inhibit rotation of the member in a second direction counter to said first direction of rotation of the member.

Preferably, said means interconnecting the handle and said member includes a first pawl on the handle means, said pawl movable between an engaged position and a disengaged position, and wherein, in the engaged position the pawl is biased into engagement with a toothed ratchet, fixed to rotate with said member, so as to allow relative rotation between the handle and the member in one direction but to inhibit relative rotation therebetween in the counter direction.

Conveniently, said ntirrotation means includes a second pawl movable between an engaged position and a disengaged position, and wherein, in the engaged position it is biased into engagement with the toothed ratchet so as to allow rotation of the ratchet and member relative to the body in one direction but to inhibit rotation of the ratchet in the counter direction, said first and second pawls being arranged such that when both are in the engaged position, rotation of the handle in said one direction of rotation thereof will rotate said member in the first direction thereof and during rotation of the handle in said other direction thereof the second pawl will inhibit rotation of the member in the second direction of rotation thereof.

Advantageously, disengagement of said second pawl from the ratchet is effected by rotation of the handle in said one direction thereof to an end of the rotational travel of the handle.

Various embodiments of the invention are described, by way of example only, with reference to the accompanying drawings, in which, Figure 1 is a perspective view of a curtain tensioner according to the invention, Figure 2 is a section in a horizontal plane along the line II - II in Figure 1, Pigure 3 is a section in a vertical plane along the line III - III in Figure 1, and Figure 4 shows an alternative construction to Figure 2.

In the dxawings, a curtain tensioner includes a channelsection body 10, preferably of cast high tensile aluminium alloy The upper and lower faces of the body 10 have similar integral formations comprising central bosses 11 joined by radial ribs 12 to edge pads 13. The inner faces 14 of the body 10 are smooth and parallel.

The bosses 11 have accurate co-axialbores 15 into which are pressed flanged unlubricated bushes 16, for example of molybdenum disulphide filled nylon Within the bushes there iw rotatably housed a shaft 17 preferably of stainless steel extending upwardly from the upper boss 11.

The shaft 17 has a short longitudinal round bottomed slot 18 therein.

In use, the body 10 is affixed to the floor of a vehicle or may, for example, be located in a slot in the edge of a coaming rail and fastened thereto by screws into tapped holes 19 in the pads 13. A flexible curtain 20, of which part is shown, is wrapped around a tubular aluminium roller 21 and is tensioned, as required, by rotation of the roller about the vertical axis thereof.

After the curtain 20 has been opened, the roller 21 is pulled until it stands above the shaft 17 and is lowered thereinto A drive pin 22 fastened diametrically through the roller 21 engages in the slot 18, so that rotation of the shaft 17 causes corresponding rotation of the roller 21.

An elongate forked lever 23, comprises a handle portion 24 parallel blades 25, all integrally formed as a high tensile aluminium casting. The bushes 16 protrude into bores in the blades 25.

A cylindrical sprocket 26 having asymmetric teeth 27 is mounted on the shaft 17 and fastened thereto by a tension pin 28 through aligned diametral holes in the shaft 17 and sprocket 26. The sprocket 26 lies between the blades 25. Thin nylon washers 29 separate the blades 25 from the body 10 and from the sprocket-26.

A first pawl 30 is rotatable between the blades 2S on a pin 31, which is parallel to the shaft 17. One end of the pawl 30 has teeth corresponding to the teeth 27 on the sprocket 26. The teeth on the pawl 30 are biased into engagement with those on the sprocket 26 by a compression spring 131 housed in a bore 32 in the handle 24 and bearing against an arm 33 integral with the pawl 30 and lying adjacent the handle 24. The teeth on the sprocket 26 and first pawl 30 are shaped so that when the handle 24 is rotated anti-clockwise in Figure 2 the teeth on the pawl 30 disengage and ride ovar the teeth on the sprocket 26. Thereby, the handle 24 can rotate about the shaft 17 without corresponding rotation of the sprocket 26. Clockwise rotation of the handle 24 causes the teeth on the pawl 30 and sprocket 26 to engage firmly, whereby the handle 24 causes corresponding rotation of the sprocket 26 and the shaft 17.

Thus, clockwise rotation of the handle 24 causes the roller 21 to rotate to tension the curtain 20. To inhibit unwinding of the curtain 20, a second pawl 34 is pivoted within the body 10 on a pin 35. The paw7~34 has teeth corresponding to the teeth on the sprocket 26, the teeth being biased together by a compression spring 36 acting between the second pawl 34 and part of the body 10.

When not in use, the handle 24 lies within part of the coaxing rail and is prevented from rotation by the engagement of the first pawl 30 with the sprocket 26.

The later is prevented from rotation by the tension in the curtain and by the second pawl 34.

After the curtain 10 has been opened, it is re-tensioned by engagement of the roller 21 to the shaft 17. The operator then gxasps the handle, whilst pulling the arm 33 towards the handle 24, thereby realising the first pawl 30 from the sprocket 26 and freeing the handle 24, whiah can be swung outwards to a convenient position.

The arm 33 is then released and the handle reciprocated back and forth so as to rotate the shaft 1? in steps, thereby tensibning the curtain 20. When tension is adequate the handle 24 is returned to its inoperative position.

The curtain 20 may be slackened by pulling the arm 33 towards the handle 24 and rotating the latter through a large arc until a pin 37 extending between the blades 25 strikes the second pawl 34 and knocks it out of engagement with the sprocket 26. The sprocket 26 is thereby freed and the curtain 20 becomes slack.

The sprocket 26 and the pawls 30, 34 are preferably made of stainless steel, but can be made of glass filled acetyl, Preferably the tips and roots of the teeth on the sprocket 26 and the pawls 30, 34 are rounded to reduce wear and stress.

In an alternatlve embodiment shown in Figure 4 the pin 37 is omitted and a different form of the pawi 34 is used, which has an arm 38 protruding from the body 10.

The arm 38 can be manually operated so as to release the second pawl 34, when required.

Claims

1. A curtain tensioner comprising a body adapted for mounting to a vehicle, said body mounting a rotatable member adapted to be engageable with a curtain roller so that, when engaged thereto, rotation of the member causes corresponding rotation of the roller, a rotatable handle means operable by an operator, means interconnecting the handle and said member such that rotation of the handle in one direction of rotation imparts rotation to the member in a first direction to tension the curtain, and disengageable anti-rotation means operable on said member to inhibit rotation of the member in a second direction counter to said first direction of rotation of the member.

2. A curtain tensioner as claimed in claim 1 wherein the rotatable member is couple8 to a toothed ratchet.

3. A curtain tensioner as claimed in claim 2 wherein the means interconnecting the rotatable handle and said member includes a pawl biassed into contact with said ratchet so as to permit relative rotation between the handle means and the member in one direction but to inhibit relative rotation therebetween in the counter direction.

4. A curtain tensioner as claimed in claim 2 or claim 3 wherein the anti-rotation means includes a second pawl movable between an engaged position and a disengaged position, and wherein, in the engaged position it is biassed into engagement with the toothed ratchet so as to allow rotation of the ratchet and member relative to the body in one direction but to inhibit rotation of the ratchet in the - counter direction, said first and second pawls being arranged such that when both are in the engaged position, rotation of the handle in said one direction of rotation thereof will rotate said member in the first direction thereof and during rotation of the handle in said other direction thereof the second pawl will inhibit rotation of the member in the second direction of rotation thereof.

5. A curtain tensioner as claimed in claim 4 wherein disengagement of said second pawl from the ratchet is effected by rotation of the handle in said one direction thereof to an end of the rotational travel of the handle.

6. A curtain tensioner as claimed in claim 5 wherein the handle means carries a projection to contact and impart movement to said second pawl against the biassing thereof to effect said disengagement.

7. A curtain tensioner as claimed in any one of the preceding claims wherein said pawl is pivotally mounted on said handle means and said biasing means comprises a spring acting between said handle means and the pawl

8. A curtain tensioner as claimed in any one of claims 2 to 7 wherein the teeth of said toothed ratchet are asymmetric in shape.

9. A curtain tensioner as claimed in any one of the preceding claims wherein the body is in the shape of a substantially U-shaped channel.

10. A curtain tensioner substantially as herein deacribed with reference to the accompanying drawings.