Patent Publication Number: US-2012043290-A1

Title: Length Adjustable Member

Description:
FIELD OF THE INVENTION 
     The present invention is directed to a length adjustable member and its associated mechanism. It will be appreciated that the member may be used in either a horizontal or vertical orientation. The length adjustable members find particular application as support uprights, e.g. poles and stands, for rack assemblies, being particularly, though not exclusively, suitable for merchandising display structures. 
     BACKGROUND OF THE INVENTION 
     In retail stores, clothing and goods for sale are displayed on racks that either protrude from a wall or are freestanding and therefore include a vertical member. In the case of “mid-floor” display stands, the vertical member may have any one of a number of types of heads, such as a circular hangrail that has supporting members that fix it to the vertical member. The rack may include a single horizontal member or a plurality of, usually four, horizontal members that protrude from the top of the vertical member. A single horizontal member may extend between two vertical members. 
     Display racks, particularly those used for displaying clothing, are configured to a height so that the clothing garments are suspended without the bottom of the garments touching the floor and generally so that the garments are displayed at eye level. However, it is advantageous that these same display racks can be used for garments of different lengths and for other goods. It is therefore advantageous to make the vertical member adjustable. 
     There have been several attempts to provide an adjustable vertical member for “mid-floor” display racks. These generally include an inner tube housed within an outer tube, such that the overall length of the vertical member may be adjusted by sliding the inner tube with respect to the outer tube. The tubes may be held at the required height by providing apertures spaced down the length of the inner and outer tubes and inserting a pin through respective apertures that line up. There are a number of other systems that require additional hardware or tools to lock the vertical members at the desired height. 
     One way to lock the inner tube at the required height without additional tools or components is to provide a plurality of apertures that are spaced down the length of the outer tube. A retractable pin extends from the inner tube and locks into an aperture on the outer tube. To adjust the vertical member, the pin is manually pushed, using a finger, out of engagement with the aperture and the tubes are slid to the desired height and the pin is lined up and is biased to lock into another aperture. A substantial amount of force or a tool is usually required to disengage the pin. 
     If additional tools are required, it can be difficult for staff to quickly and easily adjust the rack. External apertures and pins make the appearance of display racks relatively industrial looking and detract from the garments and goods for sale. 
     It is a preferred object of the present invention to provide an improved length adjustable member that is adaptable as an upright in merchandising display structures, is visually appealing and can be adjusted without additional tools. 
     Reference to any prior art in the specification is not, and should not be taken as, an acknowledgment or any form of suggestion that this prior art forms part of the common general knowledge in Australia or any other jurisdiction or that this prior art could reasonably be expected to be ascertained, understood and regarded as relevant by a person skilled in the art. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention provides, a length adjustable member, including:
         an outer tubular member;   an inner tubular member slidably disposed within the outer tubular member;   a central post fixable at its base with respect to the outer tubular member and extending within the outer tubular member, the inner tubular member being slidable between the outer tubular member and the central post; and   an actuating means having an upper end and a lower end extending from the top of the inner tubular member, the lower end associated with a releasable locking mechanism and the upper end having a release mechanism;   wherein the central post includes longitudinally spaced slots and the locking mechanism includes a hinged pawl biased to engage in the slots, whereby activation of the release mechanism causes the locking mechanism to disengage the hinged pawl from a slot allowing the inner tubular member to be slid with respect to the outer tubular member and the central post.       

     Preferably, the tubular members have a rectangular cross-sectional shape. 
     The central post may be of generally rectangular cross-section. Alternatively, the central post may be formed from a flat plate of metal, which may be bent longitudinally along two lines to create a generally U-shaped cross-section, having a front central panel and two side panels. 
     The actuating means is preferably a push rod extending the length of the inner tubular member. The release mechanism at the upper end of the actuating means is preferably a push button arrangement actuable from the outside of the length adjustable member, as it preferably extends out the top of the inner tubular member. 
     The slots are preferably of a generally triangular cross-sectional shape, with a shelf portion and an angled face, cut out of the side of a solid central post. Alternatively, the slots may be apertures cut out of the front central panel of a central post with a U-shaped cross-section. 
     The hinged pawl may be attached to a guide that is slidable along the central post and encompasses the central post. The guide is preferably fixed to the lower end of the inner tubular member, such that as the inner tubular member is moved with respect to the outer tubular member and central post, the hinged pawl and connected guide move with it. 
     The hinged pawl is preferably biased by a spring to an engaged position, where a first end of the hinged pawl engages with a corresponding slot. The hinged pawl may be shaped to correspond to the shelf portion and angled face, or be shaped to have a cut-out portion to engage under an upper edge of an aperture slot. 
     Preferably, at a second end of the hinged pawl is a formation which is able to be engaged by the push rod. When the push button is pressed, the push rod pushes down on the cut out section causing it to pivot against the bias of the spring and disengage from the slot. 
     The push rod preferably includes an abutting means, such as a circlip, above a spring. When the push rod is pushed down, the abutting means preferably compresses the spring against the guide, and, when released, the spring biases the push rod upward and away from the cut out section, allowing the hinged pawl to pivot back into engagement with a corresponding slot. 
     Preferably, the upper end of the push rod is stabilised by a stabilising means that slides along the inside of the inner tubular member with the push rod. 
     Advantageously, the length adjustable member is incorporated in a merchandising display stand. 
     Preferably, at the upper end of the length adjustable member is a substantially horizontal arm. The push button preferably protrudes through the arm. 
     According to a further aspect of the invention, there is provided a mechanism for a length adjustable member having an outer tubular member and an inner tubular member slidably disposed within the outer tubular member, the mechanism including:
         a central post fixable at its base with respect to the outer tubular member and capable of extending within the outer tubular member; and   an actuating means having an upper end capable of extending from the top of the inner tubular member and a lower end, the lower end associated with a releasable locking mechanism and the upper end having a release mechanism;   wherein the central post includes longitudinally spaced slots and the locking mechanism includes a hinged pawl biased to engage in the slots, whereby activation of the release mechanism causes the locking mechanism to disengage the hinged pawl from a slot allowing the inner tubular member to be slid with respect to the outer tubular member and the central post.       

    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will now be described, by way of example only, with reference to the accompanying drawings, in which: 
         FIG. 1  is a perspective view of a length adjustable member according to an embodiment of the present invention; 
         FIG. 2  is a perspective view of the member of  FIG. 1  with the upper section exploded; 
         FIG. 3  is a cross-sectional side view of a member in the engaged position; 
         FIG. 4  is a cross-sectional side view of the member of  FIG. 3  in the disengaged position; 
         FIG. 5  is a perspective cut-away view of the member; 
         FIG. 6  is a partially exploded perspective view of the member; and 
         FIGS. 7A to 7F  are perspective views, with exploded detail of a mechanism for a length adjustable member according to a second embodiment of the present invention, with  FIG. 7B  showing two alternative button embodiments; 
         FIG. 8  is a cross-sectional front view of the mechanism of  FIG. 7  with the release mechanism depressed and the hinged pawl disengaged; 
         FIG. 9  is a cross-sectional front view similar to  FIG. 8 , with the release mechanism released and the hinged pawl engaged; 
         FIG. 10  is a perspective view, with a tubular member shown in cross-section, of the mechanism of  FIG. 7 ; 
         FIG. 11A  is a cross-sectional side view of the mechanism of  FIG. 7  installed in a length adjustable member; 
         FIG. 11B  is a perspective view of the push button of  FIG. 11A ; 
         FIG. 11C  is a cross-sectional side view of the base of the length adjustable member of  FIG. 11A ; 
         FIG. 11D  is a cross-sectional partial side view of a length adjustable member and mechanism according to a further embodiment; and 
         FIG. 11E  is a perspective view of a push button. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     A length adjustable member  10  is illustrated as including an outer tubular member  12  and an inner tubular member  14 , slidably disposed within the outer tubular member  12 , such that the overall height of the length adjustable member  10  may be varied. The tubular members  12 ,  14  are of generally rectangular cross-section. At the top of the inner member  14  extends, relatively perpendicularly, an arm  16  for displaying articles, such as clothing from hangers. The outer tubular member  12  may be fixed to a structure or stand. 
     The arm  16  is removable, such that different shaped or sized arms can be used to suit the application of the member  10 . As shown in  FIG. 2 , the arm includes a downwardly projecting attachment portion  18  of generally rectangular cross-section that slots into the open top  19  of the inner tubular member  14 . The inner tubular member  14  and attachment portion  18  have corresponding holes  20 ,  22  through which a fastener  24  is secured. In the embodiment illustrated, the arm is of circular cross-section and the tubular members are of square cross-section, therefore a cap  26  is inserted over the attachment portion  18  to ensure a snug fit and visually appealing appearance, as seen in  FIG. 1 . Cap  26  has a bottom edge  26   a  that engages and matches the top edge of tubular member  14 , and an upper profile  26   b  that conforms to the transverse curvature of arm  16  and therefore snuggly seats the arm. The fastener  24  is easily removed, allowing the substitution of an alternate arm, having either circular or rectangular cross-section. The arm may extend out in more than one direction from the length adjustable member  10 . 
     At the upper end of the inner tubular member  14 , projecting through a hole in the top of the arm  16 , is a release mechanism in the form of a push button  28 . When the button  28  is pressed it releases a locking mechanism  48 , to be described below, that allows the inner tubular member  14  to be slid in and out of the outer tubular member  12  to adjust the overall height of the member  10 . This allows articles, such as garments, to be displayed at different heights, depending on the need of the particular garments. 
     As can be seen best from  FIGS. 3 and 4 , inside the member  10  is a central post  30  which is fixed at its lower end  32  to the outer tubular member  12  via a base  33 , secured by fastener  35 . The inner tubular member  14  is slidable between the central post  30  and the outer tubular member  12 . The central post includes an array of longitudinally space slots  34  on one side. As best shown in  FIG. 5 , the central post  30  is of generally rectangular cross-section, with the slots  34  cut out of one side. The slots  34  are of a generally triangular shape with a shelf portion  36  and an angled face  38 . 
     An actuating means  40  includes a push rod  42  that has an upper end  44  and a lower end  46  and extends from the top to the bottom of the inner tubular member  14 . The upper end  44  is attached to the push button  28 . The lower end  46  is associated with a releasable locking mechanism  48 . 
     The locking mechanism  48  includes a hinged pawl  50  that is pivotable about pivot pin  52 . The pawl  50  is attached to a guide  54  that is slidable along central post  30  and encompasses the post ( FIG. 5 ). The guide  54  provides support to the central post  30  at this higher point, as it is otherwise only fixed at lower end  32 . The guide  54  is fixed to the lower end of the inner tubular member  14 , by the inner tubular member  14  slotting over the upper portion  54   a , the lower portion  54   b  extends out of the bottom of inner tubular member  14  ( FIG. 6 ). The inner tubular member  14  is moved with respect to the outer tubular member  12  and central post  30 , the hinged pawl and connected guide  54  move with it. The upper portion  54   a  includes a channel  55  that creates room for a spring  56 . The lower portion  54   b  has the hinged pawl  50  pivotally mounted via pin  52 . 
     The hinged pawl  50  is biased by the spring  56 , as shown in  FIG. 6 , to an engaged position, in which a first end  58  of the pawl engages with a corresponding slot  34 . The pawl  50  is shaped to correspond to the shelf portion  36  and angled face  38  and prevents movement of the inner tubular member  14 . 
     At a second end  60  of the hinged pawl  50  there is a formation, or cut out section,  62 . When the button  28  is pressed, the push rod  42  is pushed down and its lower end  46  pushes down on the cut out section  62 , causing the hinged pawl  50  to pivot against the bias of spring  56  and disengage from the slot  34 . The push rod  42  includes an abutting means in the form of circlip  66 , and when the push rod  42  is pushed down, the circlip  66  compresses a spring  64  against the guide  54 . When the button  28  is released, the spring  64  biases the push rod  42  upward and away from the cut out section  62  of the pawl  50 , allowing the pawl  50  to pivot back into engagement with a corresponding slot  34 . The upper end  44  of the push rod  42  is stabilised by a brace  68  that slides along the inside of the inner tubular member  14  with the push rod  42 . 
     As shown best in  FIGS. 3 ,  4  and  6 , the push rod  42  includes a number of bends. The uppermost bend at  43   a  is to enable space for the attachment portion  18  and fastener  24 . The bend at  43   b  brings the push rod  42  back to the centre of the inner tubular member  14 . The bend at  45   a  brings the push rod  42  beside the central post  30  and spaced from it to minimise interference. The bend at  45   b  then brings the lower end  46  closer to the central post  30  to line up with the cut out section  62  and make room for the spring  56 . 
     An alternative embodiment is illustrated in  FIGS. 7 through 11 , where like reference numerals preceded by a 1 are used to denote like parts. The embodiment shows a mechanism or kit  101  for use with a separate outer tubular member  112  and/or inner tubular member  114  to create a length adjustable member  100 . The main difference between this embodiment and the embodiments shown in  FIGS. 1 through 6  is that the central post  130  is made from a flat plate of metal, being bent longitudinally along two lines to create a generally U-shaped cross-section, having a front central panel  129  and two side panels  131 . Slots  134  are cut into the central panel  129  for engagement by the hinged pawl  150  of the releasable locking mechanism  148 . This construction reduces weight and manufacturing costs. 
     The guide  154  for the hinged pawl  150  is longer and includes a slot  151  that slides over the central post  130 . The upper portion  154   a  includes a passage  153  into which the lower end  146  of the push rod  142  is inserted. The push rod  142  in this embodiment is straight along its length. Its upper end  144  includes a threaded section, which enables the push button  128  to be screwed on. At the bottom of the push button  128  is a brace  168  that ensures the push button and push rod are securely located within the inner tubular member  112  without lateral movement. An alternate push button  128 ′ is shown in  FIGS. 7B ,  11 D and  11 E and is rectangular and is able to protrude directly out of the upper end of the inner tubular member  112 . In the embodiment shown in  FIG. 11D , the support arm  116  is welded to the inner tubular member, instead of being removably attached, as in the other embodiments. 
     The length adjustable member is visually appealing, as it has a smooth outer surface, without interruption from external apertures spaced along the length of the outer tubular member, which can create a rather industrial looking product. The easy press button action of the present invention requires no extra tools and is very simple to operate, particularly in comparison to prior art systems. A press button action is more intuitive and easier to operate than more complicated prior art systems that require alternate means for adjusting. The push button mechanism is able to be used for round and square cross-sectional tubular members, as opposed to rotational locking mechanisms, which are only appropriate for circular tubular members. Another advantage over some prior art systems is that the locking mechanism relies on mechanical locking, rather than frictional locking, which is known to fail after multiple uses. 
     It will be understood that the invention disclosed and defined in this specification extends to all alternative combinations of two or more of the individual features mentioned or evident from the text or drawings. All of these different combinations constitute various alternative aspects of the invention.