Thin-walled bridge mandrel

A bridge mandrel adapted for mounting on a shaft or roller having an outer surface, the mandrel comprising:

• a thin-walled, cylindrical metal tube having an inner surface, an outer surface, and two ends defining a length;
• a pair of end caps, one at each end of the metal tube, each end cap having an outer surface adjacent the inner surface of the tube, and a central bore to receive the shaft or roller, such that a cavity is created between the outer surface of the shaft or roller and the inner surface of the metal tube;
• at least one of the end caps further including a passageway from the cavity through the tube to the outer surface thereof, such that the cavity may be pressurized to assist in installing and removing an outer sleeve onto, and off of, the tube;
• and
• a polymeric layer outside the metal tube defining a precise, desired final diameter.

A bridge mandrel adapted for mounting on a shaft or roller having an outer surface, the mandrel comprising:

• a thin-walled, cylindrical metal tube having an inner surface, an outer surface, and two ends defining a length;
• a pair of end caps, one at each end of the metal tube, each end cap having an outer surface adjacent the inner surface of the tube, and a central bore to receive the shaft or roller;
• a fiber-reinforced layer covering the outer surface of the metal tube;
• and
• a polymeric layer covering the fiber-reinforced layer defining a precise, desired final diameter.

A bridge mandrel adapted for mounting on a shaft or roller having an outer surface, the mandrel comprising:

• a steel tube having an inner surface and an outer surface defining a wall thickness of 0.125 inches or less, and two ends defining a length of 96 inches or less;
• a pair of end caps, one at each end of the steel tube, each end cap having an outer surface adjacent the inner surface of the tube, and a central bore to receive the shaft or roller, such that a cavity is created between the outer surface of the shaft or roller and the inner surface of the metal tube;
• at least one of the end caps further including a passageway from the cavity through the tube to the outer surface thereof, such that the cavity may be pressurized to assist in installing and removing an outer sleeve onto, and off of, the tube;
• and
• a hard polyurethane layer outside the metal tube machined to achieve a precise final circumference of 36 inches or less.