GB1594138A - Roller blind mechanism - Google Patents

Description

(54) A ROLLER BLIND MECHANISM (71) I, Bo VALTER SEGERLJUNG, Karlbergsvägen 10, S-186 00 Vallentuna, Sweden, a Swedish Citizen, 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: The present invention relates to roller blind mechanisms.

Roller blind mechanisms usually comprise an elongate carrier member in the form of a rod or pipe to which the foil or cloth material is attached either permanently or releasably.

The mechanism includes mounting pins at the end of the elongate carrier member which are adapted to be fixedly received by supports so that when the foil or cloth material is being unrolled from or rolled up on the carrier member the latter rotates with respect to the pins.

Usually the carrier member is spring loaded so that unrolling of the foil or cloth material by manual operation simultaneously tensions the spring and when the manual actuation is removed the spring tension causes the carrier member to return to its initial position causing the foil or cloth material to become rolled up on the carrier member. To prevent such rolling up action when not required the mechanism also includes a latch which can be set to hold the unrolled foil or cloth material in a desired position but which can be released to allow the spring to roll up the foil or cloth material when required. Usually the latch has several lightweight members which are movable radially with respect to the longitudinal axis of the roller blind mechanism and these members are held in their inoperative position when the mechanism rotates due to centrifugal force.

The return spring for the carrier member is usually tensioned to an extent proportional to the amount by which the foil or cloth material has been unrolled from the carrier member and consequently the tensioning varies and to provide adequate tension for a relatively short length of unrolled foil or cloth material causes consequential establishment of an excessive tension when the foil or cloth material is unrolled to its maximum extent. This tends to result in an overrapid rotation of the carrier member when driven by the spring tension resulting in damage to the mechanism, to the supports to which the mechanism is secured and to the foil or cloth material.

It is an object of the present invention to provide an improved form of roller blind mechanism.

According to the present invention there is provided a roller blind mechanism comprising an elongate carrier member for foil or cloth material the carrier member being rotatably mounted on a shaft arrangement adapted for fixed attachment to a support, spring means interconnecting the carrier member and the shaft arrangement whereby the carrier member is resiliently biassed towards a predetermined rotational position, a latch for releasably securing the carrier member in a selected rotational position in opposition to said resilient bias, and brake means for restricting the rotational speed of the carrier member in rotating towards said predetermined rotational position under the influence of said resilient bias, said brake means comprising at least one non-rotatable brake element forming part of the shaft arrangement, at least one weight segment constrained for rotary movement with said carrier member and radially movable by centrifugal force, and means for effecting engagement between said brake element and said weight segment consequential to said centrifugally induced radial movement whereby braking of the rotational speed of the carrier member is provided by friction action being established.

Embodiments of the present invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is a longitudinal section view of part of a roller blind mechanism in accordance with a first embodiment; Figure 2 is a sectional view on line II-II of Figure 1; Figure 3 is a sectional view on line III-III of Figure 1; Figure 4 is a longitudinal sectional view of part of a roller blind mechanism in accordance with a second embodiment; and Figure 5 illustrates a third embodiment.

In the drawings an elongate carrier member 10 is in the form of a tube having a longitudinally extending groove 13 in which is secured by means of a metal or plastics rod 12 one end of a foil or cloth material 11. Thus the material 11 is quickly attachable to the tube 10 without the need for nails or the like. As is shown in Figure 1 the end of tube 10 is closed with a cap assembly which provides bearing surfaces for a shaft pin 16 which protrudes from the cap assembly to be received in a fixed manner by a support member (not shown). The other end of tube 10 is closed in a similar manner and similarly has a projecting pin or shaft so that the mechanism can be mounted on fixed supports with the tube 10 and the end cap assemblies rotatable as a body with respect to the shafts or pins 16.

As is best shown in Figure 1 pin 16 projects into the interior of the tube 10 where it is secured to an extension rod 17 the left hand end of which provides a fixed attachment for one end of a coil spring 18 the other end of which is secured to wall 15' which forms an inner part of the end cap assembly and which is secured to tube 10 by means of sleeve portion 14'. Thus rotation to tube 10 caused by manual pulling of material 11 causes spring 18 to become tensioned since pin 16 and rod 17 are held against rotation by the support members (not shown).

In order to latch the mechanism in any desired position of the material 11 the pin 16 has a central portion which is provided with a series of circumferential abutments 21 and the end cap assembly houses three discs 19 each between radially extending walls 20, 20' secured to or integral with an outer cap portion 14 which in turn is secured to the inner cap portion 14', 15'. The latch operates by virtue of gravity actuating two of the three discs 19 so that when material 11 is being unroled from tube 10 the discs 19 ride over the abutments 21 on pin 16 due to the curvature of pin 16 in one rotational direction and when this unrolling action ceases one of the three discs will act as a stop and be engaged by one of the abutments 21.

It will be appreciated that the latch mechanism may utilise pivotal hook members arranged to engage with or be disengaged from the abutments on pins 16 according to gravitational forces.

In addition to the latch the end cap assembly incorporates a centrifugal brake which is arranged to operate automatically to prevent overrapid return of the tube 10 to its initial position when driven by spring 18.

In the first embodiment the brake comprises a circular flange 16' integral with the pin 16 and which is engageable with the adjoining face of wall 15' in accordance with the radial position of three arcuate weight segments 27 located between walls 20, 20' so as to be constrained to move in rotation with the outer cap portion 14.

Centrigugal forces cause segments 27 to be moved radially outwardly from the positions illustrated in Figures 1 and 3 resulting in inclined end faces 31 engaging the similarly inclined face 22 on wall 15 of cap portion 14 and resulting in axial movement of the weight segments so that faces 31 engage flange 16'.

Thus both surfaces of flange 16' engage rotating surfaces with the consequential establishment of friction forces providing an automatic braking action which is obtained at a predetermined rotational speed and which is maintained to prevent overrapid return of the tube to its initial position.

In the second embodiment as illustrated in Figure 4 pin 16" carries two conical brake discs 29,29' which are axially displaceable by means of splines on the pin 16" to engage conical faces 26,26' on the end cap assembly in accordance with the radial position of weight segments 28,28' each having opposed inclined surfaces. In this embodiment weight segments 28,28" are radially movable along pins 30,30' extending through the end cap assembly. The latch of the type described in the first embodiment is of course also present in Figure 4.

In the third embodiment which is illustrated schematically in Figure 5 the end cap assembly is in two halves 23 each containing a weight segment 24 with a planar surface 24' which bears against a bead 23'. The segments 24 have inclined side surfaces (not shown) which can be brought into engagement with brake discs 29, 29' or conical surfaces 26,26' (as in Figure 4).

The upper part of Figure 5 shows the position of the weight segment 24 when the mechanism is being returned to its initial position under the influence of the spring. Thus segment 24 is illustrated as having been displaced by centrifugal force toward the periphery of member 23.

The lower part of Figure 5 shows the position of segment 24 when the mechanism is being rotated away from its initial position in which case segment 24 is displaced away from the periphery of member 23. The latch of the previous embodiments may also be used with Figure 5.

WHAT I CLAIM IS: 1. A roller blind mechanism comprising an elongate carrier member for foil or cloth material the carrier member being rotatably mounted on a shaft arrangement adapted for fixed attachment to a support, spring means interconnecting the carrier member and the shaft arrangement whereby the carrier member is resiliently biassed towards a predetermined rotational position, a latch for releasably securing the carrier member in a selected rotational position in opposition to said resilient bias, and brake means for restricting the rotational speed of the carrier member in rotating towards said predetermined rotational position under the influence of said resilient bias, said brake means comprising at least one non-rotatable brake element forming part of the shaft arrangement, at least one weight segment constrained for rotary movement with said carrier member and radially movable by centrifugal force, and means for effecting

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

Claims (5)

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

   11 is quickly attachable to the tube 10 without the need for nails or the like. As is shown in Figure 1 the end of tube 10 is closed with a cap assembly which provides bearing surfaces for a shaft pin 16 which protrudes from the cap assembly to be received in a fixed manner by a support member (not shown). The other end of tube 10 is closed in a similar manner and similarly has a projecting pin or shaft so that the mechanism can be mounted on fixed supports with the tube 10 and the end cap assemblies rotatable as a body with respect to the shafts or pins 16.

   As is best shown in Figure 1 pin 16 projects into the interior of the tube 10 where it is secured to an extension rod 17 the left hand end of which provides a fixed attachment for one end of a coil spring 18 the other end of which is secured to wall 15' which forms an inner part of the end cap assembly and which is secured to tube 10 by means of sleeve portion 14'. Thus rotation to tube 10 caused by manual pulling of material 11 causes spring 18 to become tensioned since pin 16 and rod 17 are held against rotation by the support members (not shown).

   In order to latch the mechanism in any desired position of the material 11 the pin 16 has a central portion which is provided with a series of circumferential abutments 21 and the end cap assembly houses three discs 19 each between radially extending walls 20, 20' secured to or integral with an outer cap portion 14 which in turn is secured to the inner cap portion 14', 15'. The latch operates by virtue of gravity actuating two of the three discs 19 so that when material 11 is being unroled from tube 10 the discs 19 ride over the abutments 21 on pin 16 due to the curvature of pin 16 in one rotational direction and when this unrolling action ceases one of the three discs will act as a stop and be engaged by one of the abutments 21.

   It will be appreciated that the latch mechanism may utilise pivotal hook members arranged to engage with or be disengaged from the abutments on pins 16 according to gravitational forces.

   In addition to the latch the end cap assembly incorporates a centrifugal brake which is arranged to operate automatically to prevent overrapid return of the tube 10 to its initial position when driven by spring 18.

   In the first embodiment the brake comprises a circular flange 16' integral with the pin 16 and which is engageable with the adjoining face of wall 15' in accordance with the radial position of three arcuate weight segments 27 located between walls 20, 20' so as to be constrained to move in rotation with the outer cap portion 14.

   Centrigugal forces cause segments 27 to be moved radially outwardly from the positions illustrated in Figures 1 and 3 resulting in inclined end faces 31 engaging the similarly inclined face 22 on wall 15 of cap portion 14 and resulting in axial movement of the weight segments so that faces 31 engage flange 16'.

   Thus both surfaces of flange 16' engage rotating surfaces with the consequential establishment of friction forces providing an automatic braking action which is obtained at a predetermined rotational speed and which is maintained to prevent overrapid return of the tube to its initial position.

   In the second embodiment as illustrated in Figure 4 pin 16" carries two conical brake discs 29,29' which are axially displaceable by means of splines on the pin 16" to engage conical faces 26,26' on the end cap assembly in accordance with the radial position of weight segments 28,28' each having opposed inclined surfaces. In this embodiment weight segments 28,28" are radially movable along pins 30,30' extending through the end cap assembly. The latch of the type described in the first embodiment is of course also present in Figure 4.

   In the third embodiment which is illustrated schematically in Figure 5 the end cap assembly is in two halves 23 each containing a weight segment 24 with a planar surface 24' which bears against a bead 23'. The segments 24 have inclined side surfaces (not shown) which can be brought into engagement with brake discs 29, 29' or conical surfaces 26,26' (as in Figure 4).

   The upper part of Figure 5 shows the position of the weight segment 24 when the mechanism is being returned to its initial position under the influence of the spring. Thus segment 24 is illustrated as having been displaced by centrifugal force toward the periphery of member 23.

   The lower part of Figure 5 shows the position of segment 24 when the mechanism is being rotated away from its initial position in which case segment 24 is displaced away from the periphery of member 23. The latch of the previous embodiments may also be used with Figure 5.

   WHAT I CLAIM IS: 1. A roller blind mechanism comprising an elongate carrier member for foil or cloth material the carrier member being rotatably mounted on a shaft arrangement adapted for fixed attachment to a support, spring means interconnecting the carrier member and the shaft arrangement whereby the carrier member is resiliently biassed towards a predetermined rotational position, a latch for releasably securing the carrier member in a selected rotational position in opposition to said resilient bias, and brake means for restricting the rotational speed of the carrier member in rotating towards said predetermined rotational position under the influence of said resilient bias, said brake means comprising at least one non-rotatable brake element forming part of the shaft arrangement, at least one weight segment constrained for rotary movement with said carrier member and radially movable by centrifugal force, and means for effecting

   engagement between said brake element and said weight segment consequential to said centrifugally induced radial movement whereby braking of the rotational speed of the carrier member is provided by friction action being established.
2. 2. A mechanism according to Claim 1, wherein said shaft arrangement comprises a stub shaft integrally incorporating a disc flange which forms said brake element, and said engagement effecting means comprises mutually-engaging inclined surfaces on the weight segment and on the carrier member.
3. 3. A mechanism according to Claim 1, wherein said shaft arrangement comprises a stub shaft to which is connected by splines a disc flange forming said brake element.
4. 4. A mechanism according to Claim 3, wherein two conical disc flanges are mounted on the stub shaft by said splines, the weight segment being located between said two disc flanges, and said engagement-effecting means comprises mutually-engaging inclined surfaces on the weight segment and on the disc fingers.
5. 5. A roller blind mechanism substantially as hereinbefore described with reference to any one of the embodiments illustrated in the accompanying drawing.