AU2004100095A4 - Retractable bollard - Google Patents

Description

P/00/011 Regulation 3.2B

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR AN INNOVATION PATENT Name of Applicant: Address of Applicant: Actual Inventor: Address for Service: Image Bollards Pty Ltd 477B Charles Street NORTH PERTH WA 6006 Michael DIXON Griffith Hack, Patent and Trade Mark Attorneys, 6th Floor, 256 Adelaide Terrace, Perth, Western Australia, 6000.

Complete Specification for the invention entitled: RETRACTABLE BOLLARD Details of Associated Provisional Applications: Application No.: 2003905135 Dated: 22 September 2003 The following is a full description of this invention, including the best method of performing it known to me:- 2 Retractable Bollard Field of the Invention The present invention relates to a retractable bollard.

Background of the Invention Retractable bollards are characterised by a tubular housing in which resides a post that can be extended from and retracted into the housing. When the bollard is not in use the post is fully retracted within the housing.

When it is desired to deploy the bollard in order to control access to and from an area, the post is extended from the housing and locked in the extended position.

The posts are made from steel and, necessarily in order to perform their function, are of a substantial strength and mass. As a result, reasonable physical strength is required in order to move the post to the extended position. When returning the post to the retracted position, a user may either simply unlock the post and allow it to fall by action of gravity back into its housing or alternately hold the post and lower it into the housing. If the user simply allows the post to fall by action of gravity to the retracted position then the bollard and in particular any associated locking mechanisms may become damaged. Alternately, an operator must have sufficient strength to hold the post and slowly lower it into the housing. In addition when physically lifting or lowering the post a user will often bend over, rather than squat and use their legs, which can cause back injury.

h:\rosg\keep\speci\inn\P52192 Image Bollards Retractable Bollard Innovation February 2004 3 Summary of the Invention The present invention was developed to alleviate the abovementioned problems. In its broadest form the present invention is a retractable bollard which incorporates a system or mechanism for assisting in the extension and/or retraction of the post.

According to one aspect of the present invention there is provided a retractable bollard comprising: a housing; a post moveable between a retracted position where said post is substantially wholly disposed within said housing and an extended position where a length of said post is extended from said housing; and, a bias system coupled to said post to bias said post toward said extended position.

In one embodiment, said bias system comprises at least one counterweight coupled to said post, said at least one counterweight moveable within said housing in a direction opposite to a direction of motion of said post as said post is moved between said retracted and extended positions.

Preferably said bias system comprises first and second counterweights, one of each coupled to opposite sides of said post.

Preferably said housing comprises a central compartment in which said post is retained and first and second side compartments one on each side of said central compartment, wherein said first counterweight is located in said first h:\rosg\keep\speci\inn\P52192 Image Bollards Retractable Bollard Innovation February 2004 4 compartment and said second counterweight is located in said second compartment.

Preferably said bollard further comprises a first releasable lock for releasably locking said post in said extended position.

Preferably said first releasable lock is automatically deployed when said post reaches said extended position.

Preferably said first releasable lock comprises a first member biased toward a locked state and a first capture means provided in said housing and in a position whereby said first member engages said first capture means when said post is in said extended position to thereby lock said post in said extended position.

Preferably said first member is supported by said post.

Preferably said first member comprises a pin or rod and a bias mechanism for biasing said pin or rod into engagement with said first capture means.

Preferably said first releasable lock includes a release mechanism coupled to said first member to disengage said first member from said first capture means against the bias of said bias mechanism.

Preferably said bollard further comprises a second releasable lock for releasably locking said post in said retracted position.

Preferably said second releasable lock is automatically deployed when said post is in said retracted position.

Preferably said second releasable lock comprises a second member biased toward a locked state and a second capture h:\rosg\keep\speci\inn\P52192 Image Bollards Retractable Bollard Innovation February 2004 5 means provided in said housing at a position whereby said second member is engaged by said second capture means when said post is in said retracted position to thereby releasably lock said post in said retracted position.

According to a further aspect of the present invention there is provided a retractable bollard comprising: a housing; a post moveable between a retracted position where said post is substantially wholly disposed within said housing and an extended position where a length of said post is extended from said housing; and, an energy storage apparatus coupled to said post whereby energy can be transferred between said energy storage apparatus and said post to control motion of said post between said retracted and extended positions, wherein when said post is required to be moved in a direction opposite to a direction of action of gravitational force on said post, energy is transferred from said energy storage system to said post to assist moving said post against said gravitational force and, when said post is required to be moved in a direction coincident with said direction of gravitational force, energy derived by application of said gravitational force to said post is transferred to said energy storage apparatus to thereby reduce the effect of said gravitational force on said motion of said post.

Preferably said energy storage apparatus comprises at least one counterweight coupled to said post in a manner whereby said post and at least one counterweight move simultaneously in mutually opposite directions whereby at least a portion of energy gained by motion of one of said post and said at least one counterweight in said direction of action of said gravitational force is at least partially offset by energy h:\rosg\keep\speci\inn\P52192 Image Bollards Retractable Bollard Innovation February 2004

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6 expended by motion of the other of said post and said at least one counterweight in the opposite direction.

In an alternate embodiment, said energy storage apparatus comprises one or more springs.

In yet a further embodiment, said energy storage apparatus comprises one or more pneumatic struts.

Brief Description of the Drawings An embodiment of the present invention will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 is a perspective view of an embodiment of the retractable bollard in a retracted state; Figure 2 is a perspective view of the interior of another portion of the retractable bollard with an associated bollard cap removed; Figure 3 is a view of the interior of the top portion of the bollard with the bollard cap attached; Figure 4 is a perspective view of first and second locking mechanisms incorporated in the bollard; Figure 5 is a view from an alternate angle of the locking mechanisms depicted in Figure 4; and, Figure 6 is an interior view of a bottom portion of the bollard depicting an associated post in a retracted position.

h:\rosg\keep\speci\inn\P52192 Image Bollards Retractable Bollard Innovation February 2004 7 Detailed Description of Preferred Embodiment With reference to the accompanying drawings, a retractable bollard 10 in accordance with an embodiment of the invention comprises a housing 12, a post 14 moveable between a retracted position (shown in Figures 1-3) where the post 14 is substantially wholly disposed within the housing 12, and an extended position (not shown) where a length of the post is extended from the housing 12; and, a bias system 16 disposed within the housing 12 and coupled to the post 14 for biasing the post 14 toward the extended position.

The housing 12 comprises a central compartment 18 defined by a central elongated sleeve 20 in which the post 14 is retained and first and second side compartments 22 and 24 on each side of the central compartment 18, the compartment 22 being defined by a sleeve 26 and the compartment 24 being defined by a sleeve 28. An upper end 30 of the housing 12 is closed by a cover plate 32 which is provided with a central aperture 34 through which the post 14 can move. The plate 32 extends laterally beyond the sleeves 20, 26 and 28.

A length of angle iron 36 is fixed to opposite surfaces near a lower end of the housing 12 and extends transverse to the length of the housing. The angle iron 36 assists in retaining the housing 12 within the ground.

The post 14 is in the form of a square section metal tube 38 which is closed by a plate 40 at an end adjacent the end of the housing 12 when the post 14 is in the retracted position.

The bias system 16 comprises a pair of counterweights 42 (see Figures 2 and 3) both of which are coupled to the post 14 and moveable within the housing 12, and more particularly compartments 22 and 24 of associated sleeves 26 and 28, in a direction opposite the motion of the post 14 as the post 14 is moved between its retracted and extended positions. For h:\rosg\keep\speci\inn\P52192 Image Bollards Retractable Bollard Innovation February 2004 8 example, with reference to Figure 3 where the post 14 is shown in a retracted position, if the post 14 were to be moved to the extended position so that it moves in an upward direction the counterweights 42 would move in an opposite downward direction. Similarly, assuming the post 14 were fully extended, and it was desired to return the post 14 to the retracted position, the post 14 would move in a downward direction and the counterweights 42 move simultaneously in an upward direction.

The counterweights 42 are attached by the respective straps 44 to the post 14. The straps 44 pass about rollers 46 mounted on respective axles 48 that in turn are supported by respective brackets 50 attached at the upper end of the sleeves 26 and 28 respectively. The straps 44 pass through apertures 52 provided adjacent the rollers 46 formed in the sleeves 20, 26 and 28, and extend into the central compartment 18 on either side of the post 14. The distal end of each strap 44 is passed into the post 14 through a corresponding aperture 54 near a lower end of the post 14 and engaged by a respective buckle 56 (see Figure 6) to thereby attach them to the post 14.

The counterweights 42 bias the post 14 toward the extended position by virtue of gravity acting on the counterweights 42 urging them to move toward a lower end of the housing 12 which by virtue of the connection via the straps 44 urges the post 14 toward the extended position. By forming the counterweights 42 to have a combined mass approximately the same as that of the post 14 it would be appreciated that very little external force is required to be applied to the post 14 in order to lift it to the extended position.

Indeed, after an initial external physical pull on the post 14, the bias provided by the counterweights may be sufficient to fully extend the post 14 without the need for any further lifting or pulling on the post 14 by a user.

h:\rosg\keep\speci\inn\P52192 Image Bollards Retractable Bollard Innovation February 2004 9 Similarly, when it is desired to retract the post 14 from the extended position to the retracted position, the counterweights 42 by continuing to bias the post 14 in the opposite direction effectively support the post 14 as it is retracted preventing it from free falling at an acceleration of 1g. While gravitational forces are acting on the post 14 urging it toward the retracted position, the gravitational force is effectively being countered by the motion of the counterweights in an opposite direction against gravitational force.

With the combined mass of the counterweights 42 about the same as the mass of the post 14, the effects of gravity are substantially balanced by the counterweight thereby resulting in the post 14 either moving of its own accord very slowly back into the housing 14 or requiring only a light push in a downward direction by an operator to cause it to move to the retracted position.

The counterweights 42 may be seen as a specific form of energy storage apparatus which is coupled to the post 14 enabling the transfer of energy between the energy storage apparatus on the post 14 to control the motion of the post between the retracted and extended positions. When the post 14 is in the fully retracted position, the counterweights 14 store a maximum amount of potential energy derived from gravitational force acting thereon. When it is desired to move the post 14 from the retracted position to the extended position, this potential energy is converted to kinetic energy by motion of the counterweights 42 in a downward direction which is transferred by the straps 44 to the post 14 to counter the effects of gravitational force which is acting against extension of the post 14. With the post 14 fully extended, the counterweights 42 possess a minimum amount of potential energy while the post 14 presents a maximum amount of potential energy. When it is desired to return the post 14 from the extended position to the h:\rosg\keep\speci\inn\P52192 Image Bollards Retractable Bollard Innovation February 2004 10 retracted position, kinetic energy of the post 14 is transferred to the counterweights 42 lifting them within the housing 14 thereby increasing their potential energy.

The effect of transfer of energy between the post 14 and the counterweights 42 leads to a substantial reduction of force or energy required by an external operator to physically move the post 14 between the extended and retracted positions.

The bollard 10 further comprises first and second locking mechanisms for releasably locking the post 14 in the extended and retracted positions.

The first locking mechanism 58 locks the post 14 in the extended position. The locking mechanism 58 comprises a first biased member in the form of a spring biased pin which is held within a tube 62 extending transversely of the post 14 and supported in a bracket assembly 64 attached on the inside and at a lower end of the post 14 (see in particular Figure The pin 60 engages a capture means in the form of a hole (not shown) formed transversely through an upper end of the sleeves 20 and 28. Thus when the post 14 is in the extended position, the pin 60 will by virtue of its bias automatically extend into the hole thereby automatically locking the post 14 to the extended position.

The lock 58 includes a cord 66 which acts as a release mechanism to disengage the pin 60 from the hole in order to allow the post 14 to be returned to the retracted position.

The cord 66 is attached at one end to a cam 68 on the inside near an upper end of the post 14. An opposite end of the cord 66 passes about a pulley 70 rotatably mounted in the bracket assembly 64 and coupled to the pin 60. Ideally, the cam 68 is operated by a key which turns the cam 68 to pull on the cord 66 thereby retracting the pin 60 from the hole, disengaging the locking mechanism 58 and allowing the post 14 to be returned to its retracted position.

h:\rosg\keep\speci\inn\P52192 Image Bollards Retractable Bollard Innovation February 2004 11 A second separate releasable locking mechanism 72 is provided to lock the post 14 in the retracted position. The second locking mechanism 72 comprises a second member in the form of a tongue 74 that passes through a hole 77 formed in the post 14 and which is biased toward a locked state by a spring 76 and an aperture 78 (see Figure 6) formed in the sleeves 20 and 28 which engages the tongue 74 when the post 14 is in the retracted position. The tongue 74 is provided at an end of a transversely extending plate 80 which in turn is mounted on a longitudinally extending rod 82. The rod 82 extends at its upper end through a bracket 84 attached on the inside near the top of the post 14. The upper end of the rod 82 passes through the bracket 84 and is formed with a tang 86 that can be engaged by a key (not shown) for rotating the rod 82 about its longitudinal axis. To facilitate engagement of the key with the tang 86, the plate is provided with a hole 88 through which the key can pass. The spring 76 acts on the rod 82 biasing the tongue 74 toward the locked state where it extends into the aperture 78. Thus, when the post 14 is fully retracted, the tongue 74 automatically extends into the aperture 78 thereby self-locking the post 14 in the retracted position.

Now that an embodiment of the present invention has been described in detail it would be apparent to those skilled in the relevant arts that numerous modifications and variations may be made without departing from the basic inventive concepts. Most notably, the present invention describes the use of counterweights 42 in a bias or energy storage system for assisting in the extension and retraction of the post.

However the counterweights 42 may be replaced by other mechanisms to achieve the same effect. For example, counterweights 42 may be replaced by pneumatic or gas struts which are in a relatively compressed (and thus relatively high energy) state when the post 14 is in the retracted position and bias the post 14 to the extended position.

When the post 14 is in the extended position, the gas struts h:\rosg\keep\speci\inn\P52192 Image Bollards Retractable Bollard Innovation February 2004 12 are also in a relatively extended position corresponding to a relatively low energy state. Returning the post 14 to the retracted position retracts the gas struts compressing the gas thereby increasing the potential energy of the struts.

This has the effect of supporting the post 14 as it is retracted so that it is not allowed to free fall at an acceleration of 1g. Should gas struts or similar devices be used, the straps 44 would need to be replaced by a suitable coupling system such as flanges extending laterally from the post 14 and through longitudinal slots formed in the sleeves 26 and 28 and coupled to the gas struts. It is further envisaged that the same effect can be achieved by replacing the counterweights 42 with springs. Also if desired embodiments may be formed with the use of pulleys acting between the counterweights and post to obtain a mechanical advantage (ie the pulleys can act to multiply the effect of the counterweights) thereby enabling the use of smaller (lower mass) counterweights. In such an embodiment the strap 46 may be more conveniently replaced by a steel cable and the rollers 46 replaced with pulleys. Further while the post 14 is depicted as having a square section, it can take other shapes most notably circular in which case the post resembles a cylindrical post or tube.

All such modifications and variations together with others that would be obvious to a person of ordinary skill in the art are deemed to be within the scope of the present invention the nature of which is to be determined from the above description.

In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the h:\rosg\keep\speci\inn\P52192 Image Bollards Retractable Bollard Innovation February 2004 13 presence or addition of further features in various embodiments of the invention.

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Claims (5)

1. A retractable bollard comprising: a housing; a post moveable between a retracted position where said post is subtantially wholly disposed within said housing and an extended position where a length of said post is extended from said housing; and, a bias system coupled to said post to bias said post toward said extended position.

2. A retractable bollard according to claim 1 wherein said bias system comprises at least one counterweight coupled to said post, said at least one counterweight moveable within said housing in a direction opposite to a direction of motion of said post as said post is moved between said retracted and extended positions.

3. A retractable bollard comprising: a housing; a post moveable between a retracted position where said post is substantially wholly disposed within said housing and an extended position where a length of said post is extended from said housing; and, an energy storage apparatus coupled to said post whereby energy can be transferred between said energy storage apparatus and said post to control motion of said post between said retracted and extended positions, wherein when said post is required to be moved in a direction opposite to a direction of action of gravitational force on said post, energy is transferred from said energy storage system to h:\rosg\keep\speci\inn\P52192 Image Bollards Retractable Bollard Innovation February 2004 15 said post to assist moving said post against said gravitational force and, when said post is required to be moved in a direction coincident with said direction of gravitational force, energy derived by application of said gravitational force to said post is transferred to said energy storage apparatus to thereby reduce the effect of said gravitational force on said motion of said post.

4. A retractable bollard according to claim 3 wherein said energy storage apparatus comprises at least one counterweight coupled to said post in a manner whereby said post and at least one counterweight move simultaneously in mutually opposite directions whereby at least a portion of energy gained by motion of one of said post and said at least one counterweight in said direction of action of gravitational force is at least partially offset by energy expended by motion of the other of said post and said at least one counterweight in the opposite direction.'

5. A retractable bollard according to any one of claims 1- 4 further comprising a first releasable lock for releasably locking said post in said extended position. Dated this 13th day of February 2004. IMAGE BOLLARDS PTY LTD By Its Patent Attorneys GRIFFITH HACK Fellows Institute of Patent and Trade Mark Attorneys of Australia h:\rosg\keep\speci\inn\P52192 Image Bollards Retractable Bollard Innovation February 2004