Elevator cab guidance assembly

An elevator cab assembly guidance system for guiding movement of a cab assembly over elevator guide rails in a hoistway, said guidance system comprising:

• a) a guide assembly mounted on said cab assembly for reciprocal movement against an associated one of the guide rails, said guide assembly comprising a guide means mounted at corners of the cab assembly, with each of said guide means being mounted on respective pivot arms;
• and comprising spring means operable to bias said pivot arms thereby urging said guide means against the associated guide rail;
• b) stop means on each of said pivot arms, said stop means being operable to limit the extent of spring-compressing movement of said pivot arms in a direction away from the associated guide rail;
• and
• c) automatic adjustment means connected to said spring means and operable to prevent extended contact between said cab assembly and said stop means during operation of the elevator by selectively increasing the force exerted by said spring means on said pivot arms.

An elevator cab assembly guidance system for at least partially correcting canting of the cab assembly in a hoistway resulting from uneven loading of the cab, said guidance system comprising:

• a) a pair of guide roller assemblies mounted at opposed corners of a lowermost component of the cab assembly, said guide roller assemblies being operable to contact opposed guide rails in the hoistway, each of said guide roller assemblies including guide rollers mounted for reciprocal movement within a predetermined range, against said guide rails;
• b) spring means operable to bias each of said guide roller assemblies toward said guide rails to cushion said cab assembly against vibration;
• c) contact stop means operable to limit the extent of movement of each of said guide roller toward said cab assembly;
• d) driver means connected to each of said spring means and selectively operable to increase the spring force of said spring means in response to increases in rail pressure exerted on either of said pair of guide roller assemblies;
• and
• e) detector means operably connected to said driver means to actuate the latter when said increases in rail pressure are detected, whereby one of said guide roller assemblies will be spatially adjusted to at least partially correct canting of the cab assembly resulting from uneven cab loading.