operation the guide pin 48 on tab 44 slides along slot 52 while link member 54 remains essentially stationary and the link member 64 is pulled forwardly through its pivot pin 62 at tab 46 such that the link member 64 slides relative to guide pin 66 when the lower shelf 38 is pulled all of the way forward as seen in fig4 link member 64 may be pivoted about pin 66 which has moved relative to slot 68 such that it is near the distal end 65 of link member 64 and pivoting movement of link member 64 can occur without the shoe member 72 engaging stop 73 once the lower shelf 38 has been pulled completely forward then it can swing downwardly as seen in fig5 at this point the link members 54 64 pivot at each end around pins 48 56 and 62 66 respectively the lower shelf 38 continues to swing downwardly until a bumper member 74 engages the rear liner wall 24 of the refrigeration compartment the distance 76 from the rear liner wall 24 to the rear guide pin 66 attached to the shelf support bracket 30 is less than the distance 78 from the rear liner wall 24 to the pivot pin 62 secured to the rear upstanding tab 46 on the arm member 41 such that there is a continuing gravity bias downwardly and rearwardly to hold the lower shelf member.