US20050221963A1

US20050221963A1 - Dispenser/retraction unit

Info

Publication number: US20050221963A1
Application number: US11/087,928
Authority: US
Inventors: Ian Prismall; Karl Prismall
Original assignee: Primac Ltd
Current assignee: Primac Ltd
Priority date: 2004-03-31
Filing date: 2005-03-23
Publication date: 2005-10-06
Also published as: GB2412646B; GB0505915D0; GB0407216D0; GB2412646A

Abstract

A dispenser/retraction unit comprises an elongate flexible member 14 and at least one tensioning means 16, the flexible member 14 passing around at least part of the tensioning means 16, the tensioning means 16 having a biassing load 16 applied thereto urging the tensioning means 16 in a direction tending to retract the flexible member 14.

Description

This invention relates to a dispenser/retraction unit suitable for use in the dispensing and retraction of an elongate flexible member. The invention relates, in particular, to a unit suitable for use in the dispensing and retraction of the elongate flexible member of a retractable barrier system. The unit may, however, be used in a wide range of other applications, for example in the dispensing and retraction of seat belts, ropes, electrical cables or flex, hoses, or for use in bungee jumping or fire exit applications. Although suitable for use in a wide range of applications, for convenience the description herein relates primarily to retractable barrier systems.
The dispenser and retraction unit of a retractable barrier system typically takes the form of a rotatable spool, a coiled spring being provided to apply a biassing load to the spool. A flexible elongate member, usually but not exclusively in the form of webbing, is wound onto the spool. In use, when a barrier is required, the webbing is pulled from the spool, rotating the spool and thereby stressing the spring. Upon release of the webbing, the spring causes the spool to rotate thus retracting the webbing.
It has been found that barriers formed using a long span of a flexible elongate member are severely limited where units of this type are used as the number of turns of flexible elongate member material and/or the number of windings permitted by the spring are limited.
It is an object of the invention to provide a dispenser/retraction unit of simple and convenient form which allows a long length of flexible elongate member material to be used.
According to the present invention there is provided a dispenser/retraction unit comprising an elongate flexible member and at least one tensioning means, the flexible member passing around at least part of the tensioning means, the tensioning means having a biassing load applied thereto urging the tensioning means in a direction tending to retract the flexible member.
The tensioning means conveniently comprises a pulley, roller or similar component, but it will be appreciated that other arrangements are possible, for example the tensioning means could comprise a rod or bar around which the flexible member extends. The tensioning means is conveniently arranged to translate, for example it may be moveable linearly or generally linearly by the biassing load, in use, but it will be appreciated that other forms of movement, for example movement along an arcuate path, are possible.
The flexible elongate member may be of an elastic material.
The tensioning means may be biassed by means of weight. Alternatively it may be resiliently biassed, for example by means of a spring or a length of a suitable elastic material. A further possibility is to use a gas strut to provide the biassing load.
The unit may further comprise one or more additional tensioning means around at least part of which the elongate member passes. One or more of the additional tensioning means may be fixed. One or more of the additional tensioning means may be moveable and have a biassing load applied thereto. The biassing load may be applied commonly to a plurality of the tensioning means, or alternatively separate biassing loads may be provided for each tensioning means. Alternatively, the tensioning means may be arranged in groups, biassing means being associated with each group. Combinations of these arrangements are also possible.
The elongate flexible member may take a range of forms. For example, it may comprise a length of webbing, a rope or rope-like material, of, for example, round or square cross-section, an elastic material, an electrical cable or flex, or a hose.
The unit conveniently includes a housing within which the tensioning means are located, the housing having an opening or openings from which the elongate flexible member can be drawn.
The invention will further be described, by way of example, with reference to the accompanying drawings, in which:
FIG. 1 is a diagrammatic sectional view illustrating a dispenser/retraction unit in accordance with one embodiment of the invention;
FIG. 2 is a view similar to FIG. 1 illustrating the unit in an alternative condition;
FIGS. 3 and 4 are views similar to FIGS. 1 and 2 illustrating an alternative embodiment;
FIGS. 5 and 6 are views illustrating a further alternative embodiment;
FIGS. 7 and 8 are views of another alternative embodiment;
FIGS. 9 and 10 are views of further alternative embodiments; and
FIGS. 11 to 15 illustrate further alternative embodiments
Referring firstly to FIGS. 1 and 2 there is shown a dispenser/retraction unit 10 forming part of a post 12 for use in a retractable barrier system. The unit 10 comprises a flexible elongate member 14 and a tensioning means in the form of a pulley 16 around at least part of which the flexible elongate member 14 is wound. The flexible elongate member 14 further passes around an idler pulley 18. The unit 10 is located within a housing 20 defining an upright part of the post 12, the housing 20 being mounted upon a base 22 to support the housing 20 in a generally vertical or upstanding configuration.
Adjacent the idler pulley 18, the housing 20 is formed with an opening or slot (not shown) through which the flexible elongate member 14 extends. One end of the flexible elongate member 14 is firmly attached to the interior of the housing 20 by means of a suitable attachment device 24.
Within the housing 20, a weight 26 forming part of the unit 10 is provided, the weight 26 being secured to the pulley 16 to apply a downward biassing force to the pulley 16 so that, in the configuration illustrated in FIG. 1, a part of the elongate flexible member to one side of the pulley 26 lies adjacent the part of the flexible elongate member 14 to the other side of the pulley 16. In this configuration, it will be appreciated that a relatively long length of the flexible elongate member 14 is held under tension within the housing 20.
In use, when it is desired to dispense the flexible elongate member 14, for example to form part of a retractable barrier, the free end 28 of the flexible elongate member 14 is pulled to withdraw a length of the flexible elongate member 14 from the housing 20. The action of pulling the free end 28 of the flexible elongate member 14 causes the weight 26 to lift, the weight 26 occupying the position shown in FIG. 2 when the flexible elongate member 14 is almost completely dispensed.
When the barrier is no longer required, the free end 28 of the flexible elongate member 14 is released and the load applied by the weight 26 to the pulley 16 will cause the pulley 16 to fall under the action of gravity thereby retracting the flexible elongate member 14 back into the housing 20, returning to the condition illustrated in FIG. 1.
Although FIG. 1 illustrates the use of a weight 26 to apply the biassing load to the pulley 16, it will be appreciated that the biassing load may be applied through other means. For example, FIGS. 3 and 4 illustrate an arrangement in which a length of elastic material 30 is used to apply the biassing load, the material 30 being anchored at one end to the interior of the housing 20, the material 30 passing around a pulley 32 and being secured to the pulley 16 to apply the biassing load thereto. Operation of the arrangement illustrated in FIGS. 3 and 4 is very similar to that described hereinbefore and so will not be described in further detail.
It will be appreciated that a range of other modifications or alterations to the arrangements shown in FIGS. 1 and 2 are possible. For example, springs or gas struts could be used in the biassing of the pulley 16.
FIGS. 5 and 6 illustrate a further modification in which the device 24 used to secure the flexible elongate member 14 is not secured to the upper part of the housing 20, but rather is secured to the base 22 within the housing 20. A second moveable pulley 34 is provided around which the flexible elongate member 14 is wound, the additional moveable pulley 34 being urged towards the upper end of the housing 20 by means of a spring 36 whilst the pulley 16 is urged in a downward direction by means of a spring 38. In use, during dispensing of the elongate flexible member 14 from the unit, the action of pulling the free end 28 of the elongate flexible member 14 will cause the moveable pulley 16 to lift against the resilient biassing action of the spring 38 and cause the moveable pulley 34 to be forced in a downward direction against the biassing action of the spring 36. Once the elongate flexible member 14 has been dispensed to almost its fullest extent, as illustrated in FIG. 6, the pulleys 16 and 34 will be located approximately adjacent each other and, depending upon the rates of the springs 36, 38 the pulleys 16, 34 may be located close to the mid-point of the housing 20. However this need not always be the case.
Upon release of the free end 28 of the flexible elongate member 14, the springs 36, 38 will act to move the pulleys 34, 16 towards the positions illustrated in FIG. 5, thereby retracting the flexible elongate member 14 back into the housing 20.
Although in the arrangement illustrated in FIGS. 5 and 6 the pulleys 16, 34 are both biassed by means of springs 36, 38 it will be appreciated that other biassing means could be used, for example the pulleys 16, 34 could be biassed by means of elastic members as in the arrangement of FIGS. 3 and 4, and the pulley 16 could be biassed by means of a weight 26 as in the arrangement shown in FIGS. 1 and 2. A further alternative biassing means which could be used in the arrangement of FIGS. 5 and 6 is the use of gas struts, which could incorporate a damping mechanism to slow the speed at which the elongate flexible member 14 is retracted and/or dispensed. It will further be appreciated that different biassing means could be used in combination, if desired, for example to achieve a desired retraction load.
FIGS. 7 and 8 illustrate diagrammatically another arrangement using gas struts to provide the biassing loads for the pulleys. In the arrangement of FIGS. 7 and 8, four upper pulleys 40 and three lower pulleys 42 are provided each of the pulleys being biassed towards a respective end of a housing 44 by means of an associated gas strut 46. One end of a flexible elongate member 48 is secured within the housing 44 by means of a suitable fixing device 50, the elongate flexible member 48 being wrapped around the pulleys 40, 42 and passing around an idler pulley 52 before exiting the housing 44 through a slit or opening formed therein.
In use, in order to dispense the elongate flexible material 48 from the housing 44, a free end thereof is pulled, the action of pulling the elongate flexible member 48 applying a force to the pulleys 40 urging them in a downward direction against the action of the associated gas struts 46, and applying an upwardly directed force to the pulleys 42 against the action of the associated gas struts 46. FIG. 8 illustrates the position where the elongate flexible member 48 is almost entirely withdrawn from the housing 44. In this position, the gas struts 46 are stressed and urging the pulleys 40, 42 towards the positions illustrated in FIG. 7.
When the elongate flexible member 48 is to be retracted back into the housing 44, the free end thereof is released or allowed to feed in and the gas struts urge the pulleys 40, 42 towards the positions illustrated in FIG. 7 thereby retracting the elongate flexible material 48 back into the housing 44.
It will be appreciated that as, in the retracted condition shown in FIG. 7, the elongate flexible material 48 is wrapped around a number of pulleys, a relatively long length of elongate flexible material 48 can be stored within the housing 44 thus where used as part of a retractable barrier system, barriers of a relatively long length may be formed.
Although the arrangements described hereinbefore are all intended to operate with the tensioning means moving in a generally vertical direction, in use, it will be appreciated that this need not always be the case, for example where gas struts, elastic or springs are used to apply the biassing load. As a result, the housing need not be of elongate, upstanding form and could be arranged to extend horizontally or at an angle. Further, the tensioning means do not need to be moveable in the same direction as one another, and so arrangements of, for example, star-like shape are possible.
In each of the arrangements described hereinbefore, the moveable pulleys are individually biassed. However, it will be appreciated that this need not be the case and the moveable pulleys, or groups thereof, may be interconnected and biassed by a common biassing arrangement. For example FIG. 9 illustrates an arrangement in which a series of moveable pulleys 55 are provided, the pulleys 55 all being secured to a common weight 54 which is used to apply a biassing load to all of the moveable pulleys 55 simultaneously.
As well as showing the possibility of providing a common biassing arrangement for a number of pulleys the arrangement of FIG. 9 further illustrates that a single length of flexible elongate material 56 may be wrapped around the pulleys of two separate housing 58. As a result, where used as part of a retractable barrier arrangement, when a barrier is not required the two housings 58 are located adjacent one another and the elongate flexible material 56 is housed almost entirely within one or other or both of the housings 58. When a barrier is required, one of the housings 58 is moved away from the other of the housings 58, the flexible elongate material 56 forming a barrier interconnecting the two housings 58. As the two housings 58 both contain a relatively long length of flexible elongate material 56, it will be appreciated that a barrier of relatively long length can be formed.
FIG. 10 illustrates a further modification in which rather than having one end of the elongate flexible material anchored within the housing 60, both ends 62, 64 of the elongate flexible material 66 protrude through openings or slits formed in the housing 60. In use, both of the free ends 62, 64 of the flexible elongate material 66 may be retracted from the housing to form a relatively short barrier made up of upper and lower lengths of elongate flexible material 66. Alternatively, one or other but not both of the free ends 62, 64 may be pulled from the housing to form a barrier of relatively long length.
FIGS. 11 and 12 illustrate an arrangement similar to that of FIG. 9 but in which the pulleys 55 are arranged coaxially. The arrangement shown uses rope or the like as the flexible elongate member, but other types of flexible elongate member may be used. FIG. 12 shows that two units of this type may be attached to each other or formed integrally with one another. It will be appreciated that the modifications shown in FIGS. 11 and 12 may be applied to others of the arrangements described herein.
FIGS. 13 and 14 illustrate an arrangement in which the elongate flexible member 70 is wound around pulleys 72 so as to form loops of elongate flexible member material located one inside the other. The member 70 passes through a vertically or generally vertically orientated slot 74 provided in a housing 76. In order to allow the member 70 to pass through a slot so oriented, an angled deflection bar or pulley 78 is provided to move the member 70 from a horizontal configuration to a generally vertical configuration. The positioning and orientation of the deflection bar or pulley may be varied to suit the application. Alternative deflection means are possible. Again, it will be appreciated that elements of this arrangement may be incorporated into the embodiments described hereinbefore.
FIG. 15 illustrates a post suitable for use in housing a unit in accordance with the invention. Although the arrangement shown in FIG. 15 is of square cross-section, it will be appreciated that other configurations, fixed or moveable, are possible.
In the description hereinbefore, numerous references have been made to the provision of a flexible elongate member. The flexible elongate member may take a wide range of forms. For example, where the dispenser/retraction unit is to be used as part of a retractable barrier system, then the elongate flexible member may take the form of webbing. Alternatively, the elongate flexible member may take the form of a rope or rope-like material of a range of cross-sectional shapes, for example including circular and square cross-section. The material of the flexible elongate member may, in some applications, be of elastic form thereby further increasing the length of barrier which can be erected.
In the description hereinbefore reference is made to damping of the operation of the gas struts to damp dispensing and/or retraction. Damping means may also be provided where other forms of biassing means are used. For example, where weights are provided, the weights may be sized to fit the housing leaving only a small air gap therebetween. The weight and housing will thus act, to some extent, as a piston damping movement of the weight. Other damping mechanisms and techniques may be used, including damping the movement of the elongate flexible member instead of the tensioning means.
Although the description hereinbefore is of the use of the dispenser/retraction unit as part of a retractable barrier system, it will be appreciated that it may be used in a number of other applications. For example, it could be used in the dispensing and retraction of electrical cables or flexes or hoses for gas or liquids. Further possibilities include vehicle seat belts, bungee jump application, harness-type fire exit arrangements or arrangements for use in parachute jump training.
Although the description hereinbefore refers to the provision of tensioning means in the form of pulleys, it will be appreciated that the tensioning means used could take a number of forms and the term pulley should not be taken as limiting in any way.
It will be appreciated that the arrangements described hereinbefore are merely examples of arrangements falling within the scope of the invention and that a number of other possible modifications or alterations may be made.

Claims

1. A dispenser/retraction unit comprising an elongate flexible member and at least one tensioning means, the flexible member passing around at least part of the tensioning means, the tensioning means having a biassing load applied thereto urging the tensioning means in a direction tending to retract the flexible member.

2. A unit according to claim 1, wherein the tensioning means comprises a pulley, roller or similar component.

3. A unit according to claim 1, wherein the tensioning means comprises a rod or bar around which the flexible member extends.

4. A unit according to claim 1, wherein tensioning means is moveable linearly or generally linearly by the biassing load, in use.

5. A unit according to claim 1, wherein the tensioning means is movement along an arcuate path.

6. A unit according to claim 1, wherein the flexible elongate member is of an elastic material.

7. A unit according to claim 1, wherein the tensioning means is biassed by means of weight.

8. A unit according to claim 1, wherein the tensioning means is resiliently biassed.

9. A unit according to claim 8, wherein the tensioning means is biassed by means of a spring or a length of suitable elastic material.

10. A unit according to claim 8, wherein a gas strut to provide the biassing load.

11. A unit according to claim 1, further comprising one or more additional tensioning means around at least part of which the elongate member passes.

12. A unit according to claim 11, wherein one or more of the additional tensioning means are fixed.

13. A unit according to claim 11, wherein one or more of the additional tensioning means are moveable and have a biassing load applied thereto.

14. A unit according to claim 13, wherein the biassing load is applied commonly.

15. A unit according to claim 13, wherein separate biassing loads are provided for each tensioning mens.

16. A unit according to claim 13, wherein the tensioning means are arranged in groups, biassing means being associated with each group.

17. A unit according to claim 1, wherein the elongate flexible member comprises at least one of a length of webbing, a rope or rope-like material, an elastic material, an electrical cable or flex, and a hose.

18. A unit according to claim 1, further comprising a housing within which the tensioning means is located, the housing having an opening or openings from which the elongate flexible member can be drawn.

19. A retractable barrier comprising a unit according to claim 18.