Patent ID: 6539578
Filing Date: 2003-04-01
Classification: B60B,G01G,Y10T

Abstract:
A wheel assembly comprising:an elongate generally U-shaped flex member having a first leg and a second leg joined by a bridging bight, the first leg comprising a support portion adapted to be secured to an article, the second leg having a wheel rotatably mounted thereto for rotation about a wheel axis, the bight comprising a resilient first spring member which biases the first leg and the second leg away from each other to an unbiased position and is resiliently deflectable to move the wheel relatively closer to the support portion to retracted positions, a longitudinal center line extending along the length of the U-shaped flex member through each of the first leg, bight and second leg, the center line defining a U-shape lying in a flat plane normal the wheel axis when the flex member is in the unbiased position, the flex member in moving between the unbiased position and the retracted positions maintaining the center line substantially in said flat plane, the first leg comprises a central portion having a first end, a second end and two sides extending between the first and second ends with each side carrying first leg side flanges, the central portion of the first leg comprising the support portion adapted to be secured to an article, the central portion of the first leg coupled to the bight at the second end of the first leg, the first leg side flanges extending away from the central portion of the first leg towards the second leg to define with the central portion of the first leg a first channelway, the second leg comprising a central portion having a first end, a second end and two sides extending between the first and second ends with each side comprising second leg side flanges, the central portion of the second leg coupled to the bight at the first end of the second leg, each of the second leg side flanges extending away from the central portion of the second leg towards the first leg to define with the central portion of the second leg a second channelway, one of the first channelway and second channelway slidably received within the other of the first channelway and second channelway for engagement with each other to constrain the first and second legs during relative movement between the biased position and the retracted positions so that the center line is maintained substantially in said flat plane.