A drive gear arrangement for a movable wall or movable partition system, which system comprises at least one wall element and a guide rail having an upper portion configured to be disposed toward a ceiling structure and a lower portion configured to be disposed away from a ceiling structure, said drive gear arrangement comprising:
- a hanging structure;
- said hanging structure being configured to hang at least one wall element
- a carrying roller;
- said carrying roller being configured to operatively support the weight of at least one wall element;
- said carrying roller being configured to run along a guide rail to permit movement of said drive gear arrangement;
- said carrying roller having an axle about which said carrying roller rotates;
- said carrying roller having a running surface being configured to contact a lower portion of a guide rail;
- guiding rollers;
- each of said guiding rollers being configured to roll along an upper portion of a guide rail and to guide said carrying roller along a path of a guide rail;
- each of said guiding rollers having a corresponding axle about which each of said guiding rollers rotates, said axle being disposed substantially transverse to said axle of said carrying roller;
- each of said guiding rollers having a contact surface disposed around the circular circumference of each of said guiding rollers, which contact surface being configured to be disposed to contact an upper portion of a guide rail;
- each of said guiding rollers having a side surface being disposed on either side of each of said guiding rollers and being configured to radially extend from the central axis to said contact surface of each of said guiding rollers;
- at least one of said guiding rollers, being disposed on a first side of said carrying roller, being configured to be disposed in the path of movement of said carrying roller along a guide rail;
- at least one of said guiding rollers, being disposed on a second side of said carrying roller opposite said first side, being configured to be disposed in the path of movement of said carrying roller along a guide rail;
- each of said guiding rollers disposed substantially immediately adjacent said carrying roller being disposed to form a minimal gap between each of said guiding rollers and said carrying roller to minimize the length of said drive gear arrangement, which length of said drive gear arrangement being minimized to permit minimization of the radii of curvature of a curved portion of a guide rail;
- and
- said side surface of each of said at least one guiding rollers disposed on said first side and said second side of said carrying roller comprising a conical surface, said conical surface being configured and disposed to permit at least a portion of said conical surface to lie essentially on a tangent to said running surface of said carrying roller.