Slider door mechanism, running gear mechanism and closure return

A wheel and track unit for supporting a structure for movement on a track, the unit comprising:

• a wheel having a substantially flat bearing surface and supported on an axis for running on a track;
• a housing for supporting the wheel, including a convex-shaped guide separate from the wheel for maintaining the wheel on the track;
• and
• a track having a non-flat supporting surface for supporting the unit through contact with the substantially flat bearing surface of the wheel.

A wheel and track unit for supporting a structure for movement on a track, the unit comprising:

• a wheel supported on an axis;
• a housing for supporting the wheel, including a convex-shaped protruding guide separate from the wheel for maintaining the wheel on a track;
• and
• a track for supporting the wheel and housing through contact with the wheel.

A closure unit comprising:

• a track;
• a panel;
• a wheel unit for supporting the panel on the track wherein the wheel unit includes at least one rotatable wheel having a substantially flat bearing surface and supported on an axis for running on the track;
• and
• a housing for supporting the wheel, including a convex-shaped guide for maintaining the wheel on the track.

A closure unit comprising:

• a track having a non-flat supporting surface;
• a panel;
• a wheel unit supporting the panel on the track wherein the wheel unit includes at least one rotatable wheel having a substantially flat bearing surface for supporting the weight of the panel and supported on an axis for running on the track and wherein the rotatable wheel includes substantially straight internal side walls for laterally guiding the wheel unit on the track;
• and
• a housing for supporting the wheel.

A wheel and track unit for supporting and guiding a structure for movement on a track, the unit comprising:

• a housing having a guide;
• a wheel having a contact surface having a first dimension, and supported by the housing to rotate about an axis;
• and
• a track for supporting the housing and wheel and including a contact surface for contacting the contact surface of the wheel and wherein the contact surface of the track has a second dimension larger than the first dimension of the contact surface on the wheel and wherein the guide keeps the wheel on the track while permitting the wheel to move laterally on the track.