a specific embodiment of the present invention will now be described in detail with reference to the figures . 100 — item of luggage 110 — extendible handle 120 — retractable wheels 130 — cover 140 — compartment 150 — non - rotating member 160 — crossbar 170 — rotating members 180 — wheel bracket 190 — first slot 200 — secondary slot 210 — retractable pin 220 — hole ( upper ) 230 — hole ( lower ) 240 — wheel 250 — button 260 — bracket assemblies 270 — wheel housing 280 — load bearing projections 290 — plate holes 300 — supporting brackets 310 — reinforcement member 320 — blocking projection 330 — screws 340 — slots 350 — tab 360 — blocking panel 370 — spring 400 — alternative reinforcement member 410 — screw 420 — slot 430 — blocking projection 440 — spring 450 — tab 460 — engaging panel 470 — linking member fig1 shows an item of luggage 100 with an extendible handle 110 and retractable wheels 120 . further , it can be seen that the handle 100 comprises a cover 130 , which , when in a retracted position closes a compartment 140 . fig2 illustrates the underside of the luggage 100 , and clearly shows the handle 110 comprising the cover 130 and the compartment or recess 140 . fig3 shows the majority of the wheel retraction mechanism of the present invention . handle 110 is shown without the cover 130 , and is seen to comprise two substantially identical non - rotating members 150 ( each defining a secondary member ) interconnected by a crossbar 160 with an ergonomic grip which forms the portion of the handle 110 that the user holds . this crossbar could be made of plastic , composite or metal , and may be coated in textiles . non - rotating members 150 slide inside two rotating members 170 ( each defining a primary member ), each of which is connected to a wheel bracket 180 at its lower end ( with the upper end being defined as that nearest the crossbar 160 ). each rotating member 170 comprises a first actuation surface and first bearing surface comprising elongated slots : a first slot 190 and secondary slot 200 respectively . the first slot 190 is elongated and helically shaped , extending circumferentially around the rotating member 170 as it extends along its length . the first slot 190 enables and actuates the rotation of rotating member 170 . the secondary slot 190 is larger in diameter and much shorter . it does not extend along the longitudinal direction of the rotating member 170 , but instead extends purely circumferentially . both slots extend by a substantially identical angle in the circumferential direction . a retractable pin 210 is present on the inside of each non - rotating member 150 . this pin is controlled to withdraw against the action of a spring when a button on the crossbar 160 is depressed . in use these pins 210 are designed to engage with holes 220 and 230 when the non - rotating member is in an extended and retracted position respectively . these pin and hole pairs are used to lock the non - rotating member 150 with respect to the rotating member 170 . fig4 and 5 depict the rotating members 170 with wheels 240 attached . fig6 shows the majority of the wheel retraction mechanism of the present invention in a retracted position . it can be seen that locking pins 210 have engaged holes 230 . in order to retract the handle 110 , thus withdrawing non - rotating members 150 from rotating members 170 , button 250 , located on crossbar 160 , must first be pressed to withdrawn pin 210 . fig7 again depicts the wheel retraction mechanism in a retracted state , although with the inclusion of bracket assemblies 260 . bracket assemblies 260 extend through elongated slot 190 and rotating member 170 and attach to non - rotating member 150 . as the non - rotating members 150 are withdrawn from rotating members 170 , the handle 160 prevents the non - rotating members from rotating . due to the interaction of the first slot 190 and the bracket assemblies 260 ( which are fixed to the non - rotating members 170 and so can also not rotate ), the helical first slots 190 force the rotating members 170 to rotate . rotating members 170 are therefore both rotated outwards , in a direction whereby both wheel brackets 180 end up pointing upwards ( as viewed in fig7 ) when the non - rotating members 150 , and thus handle 110 is fully extended . fig1 depicts the handle 110 in a fully extended position , although this figure depicts what is the underside in fig1 . when the handle is fully extended , the retractable pins 210 mate with holes 220 . fig1 also depicts supporting brackets 300 . these brackets may contain bearings , and are also responsible for taking a proportion of the load as the luggage 100 is pulled by the handle 110 . this prevents the entire pulling force being conveyed through the bracket assemblies 260 and first slots 190 , reducing distortion , damage and wear . fig8 shows the wheel retraction mechanism in a fully retracted position . this figure illustrates the wheel housing unit 270 , which in use is attached to the luggage 100 . additionally this figure highlights how the cover 130 totally covers and conceals both the wheels 240 , and the rotating and non - rotating members 170 , 150 with respect to the outside of the luggage in which the mechanism is contained . fig9 illustrates the same image as fig8 , but this time focussing on the retracted wheels 240 . also , load bearing projections 280 are shown which act as second bearing surfaces . load bearing projections 280 are attached to the luggage 100 by screws or rivets attached via the plate holes 290 and the wheel housing 270 . load bearing projections 280 mate with secondary slots 200 . as the rotating member 170 rotates as the handle 110 is withdrawn or retracted , load bearing projections 280 move relatively along the length of secondary slots 200 . as the handle 110 , and thus wheels 240 , reach their fully extended or retracted position , load bearing projection 280 abuts the end of secondary slot 200 . load bearing projection 280 and secondary slot 200 is the main weight transferring connection between the luggage and rotating member 170 , thus it is robust in design . fig1 shows a close up of the crossbar section 160 of the handle 110 and illustrates the placement of the button 250 . fig1 shows a close up of the wheel - end of the rotating members 170 . it illustrates how the load bearing projections 280 are attached to the wheel housing 270 via the load bearing projection plate holes 290 . the wheels are shown partly absent to allow the details to be seen . fig1 to 16 show an embodiment of the reinforcement member 310 . reinforcement member 310 prevents the rotating member 170 from rotating in a retracting direction when it is locked in an extended position . fig1 and 15 show the reinforcement member 310 in a non - engaging state , when the wheels 240 are in a retracted state . fig1 and 16 depict the reinforcement member 310 , when the wheels 240 are in an extended state , and thus the reinforcement member 310 engages a blocking projection 320 located on the rotating member 170 . reinforcement member 310 is slidably attached to the luggage 100 by screws 330 located in slots 340 . as the non - rotating member 150 is extended , the bracket assemblies 260 move along first slot 190 , rotating the rotating member 170 . as the bracket assemblies 260 approach the end of the first slot 190 , they engage tab 350 . then , as the bracket assemblies 260 complete the final distance to reach the end of the first slot 190 , reinforcement member 310 is moved in a direction “ x ”. this locates the reinforcement member 310 in the position shown in fig1 and 16 . before reinforcement member 310 reaches this position , blocking projection 320 has rotated through gap a , thus when the reinforcement member 310 reaches the position shown in fig1 and 16 , blocking projection 320 is located adjacent blocking panel 360 . when in this extended state , pin and holes 210 and 220 maintain the bracket assembly 260 in position , which in turn keeps the reinforcement member 310 in the position shown in fig1 and 16 . in this position , blocking panel 360 prevents blocking projection 320 from passing , and thus prevents the rotating member 170 from rotating in a retracting direction . this produces a more robust system , since any bumps the wheels take on their side face when they are in the extended position , do not cause the wheels to distort or damage the bracket assembly 260 or first slot 190 . the shock load is taken by the reinforcement member through blocking panel 360 and blocking projection 320 . spring 370 is attached between the reinforcement member 310 and the screw 330 and pulls the reinforcement member 310 back towards the state shown in fig1 . fig1 to 20 illustrate an alternative embodiment of a reinforcement member 400 according to some aspects of the present invention . reinforcement members 400 , located on either side of one panel / side of the luggage , prevent the rotating members 170 from rotating in a retracting direction when locked in an extended position . fig1 and 19 show a reinforcement member 400 in a non - engaging state — when the wheels 240 are retracted . fig1 and 20 show the reinforcement member in an engaging state — when the wheels 240 are extended ; in this position , the reinforcement member 400 ( and in particular an engaging panel ) engages a blocking projection 430 located on the rotating member 170 , preventing the rotating member 170 from rotating back to a retracted position . the reinforcement member 400 is substantially an elongated bracket located parallel to the rotating members 170 and non - rotating members 150 . the reinforcement member 400 is slidably attached to the luggage 100 by screws 410 in elongated slots 420 . a spring 440 is connected between each reinforcement member 400 and the screw 410 located furthest from the wheel brackets 180 , biasing the reinforcement member 400 into a retracted , or non - engaging , position . similar to the reinforcement member 310 embodiment depicted in fig1 to 16 , reinforcement member 400 comprises a tab 450 located on the distal end of the reinforcement member 400 . as the non - rotating member 150 is extended , the bracket assemblies 260 move along the first slot 190 , rotating the rotating member 170 . as the bracket assemblies 260 approach the end of the first slot 190 , they engage the tab 450 . then , as the bracket assemblies 260 complete the final distance to reach the end of the first slot 190 , reinforcement member 400 is moved in a direction “ y ”. this locates the reinforcement member 400 in the position shown in fig1 and 20 . the bracket assemblies 260 should be shaped so as to engage the tab 450 . the reinforcement member 400 comprises an engaging panel 460 located adjacent the wheel bracket end of the reinforcement member 400 . the engaging panel 460 may lie in a plane substantially perpendicular to that of the tab 450 . the engaging panel 460 may extend substantially parallel to the surface or panel of the luggage 100 to which the reinforcement member 400 is attached . the engaging panel 460 is substantially “ l ” shaped , extending out from the side of the reinforcement member 400 . as such , the engaging panel 460 forms a shape similar to a square hook at its end . a linking member 470 connects the two reinforcement members 400 , located on either side of the luggage 100 . the linking member 470 comprises a substantially cylindrical rod , rigidly attached to both reinforcement members 400 at either end . a blocking projection 430 is located on the rotating member 170 . the blocking projection 430 comprises a substantially rectangular protrusion , extending from the surface of the rotating member . the blocking projection 430 is in a position such that when each rotating member 170 and reinforcement member 400 are in an extended position , the engaging panel 460 engages the blocking projection 430 . as the bracket assemblies 260 force the reinforcement members 400 in a direction away from the wheel brackets 180 , the engaging panels 460 are moved in to a position to substantially trap the blocking projection 430 , as illustrated in fig2 . due to the shape of the first slot 190 , the blocking projection has already completed it &# 39 ; s rotation into an extended position , before the bracket assemblies 260 move the engaging panels 460 into position , to engage the blocking projection 430 . when in this extended state , pin and holes 210 and 220 maintain the bracket assembly 260 in position , which in turn keeps the reinforcement member 400 in the position shown in fig1 and 20 . in this position , engaging panel 460 prevents blocking projection 430 from moving in a retracting - direction . unlike with the reinforcement member 310 of fig1 to 16 , with the reinforcement member 400 of fig1 to 20 , if the wheels 240 are forced in a retracting - direction due to an impact load , each blocking projection 430 exerts a force on the engaging panel 460 in a direction “ z ”, parallel to the panel of the luggage 100 to which the reinforcement member is attached . this is due to the arrangement of the contact between the blocking projection 430 and the engaging panel 460 . an arrangement such as that illustrated in fig1 to 20 results in the impact loads — transferred by the blocking projection 430 to the reinforcement member 400 — acting in parallel and opposite directions on each reinforcement member 400 . as such , there is no impact force transferred to the luggage 100 via the screws 410 due to the rotating members 170 attempting to move in a retracting - direction . the linking member 470 acts to connect the two reinforcement members 400 , so that any impact loads ( which would act to force the two reinforcement members 400 in opposite directions ), can cancel each other out . this reduces the stresses experienced by the panel to which the reinforcement members 400 are connected , and thus increases reliability , robustness and durability of the luggage 100 as a whole . it will be appreciated that it is not intended to limit the present invention to the above specific embodiments only . many variants will be readily apparent to one of ordinary skill in the art without departing from the scope of the appended claims .
a wheel retraction mechanism for use on travel luggage , the retraction mechanism causing the extension and retraction of one or more wheels upon relative movement of two adjacent members . the members comprise two engaging actuation surfaces which , upon relative longitudinal movement , create a movement in a different direction , which can be used to extend or retract wheels from a piece of travel luggage .