초록 ▼

By using an existing ball nut and ball nut screw of a ball nut screw assembly as master models, imprint molds can be molded from a silicone rubber material which positively profiles the threading of the ball nut and ball nut screw with the crossover channel in the master model of the ball nut. A the

By using an existing ball nut and ball nut screw of a ball nut screw assembly as master models, imprint molds can be molded from a silicone rubber material which positively profiles the threading of the ball nut and ball nut screw with the crossover channel in the master model of the ball nut. A thermoset resin is added to the imprint molds and cured to form unitized all plastic ball nuts and ball nut screws with the helical grooving for accommodating the train of balls including the crossover channel in the ball nut molded therein to thereby provide an easily reproducable ball nut and screw assembly.

대표청구항 ▼

A method of pour molding a one-piece plastic ball nut for a ball nut and screw assembly, the ball nut have formed therein an internal helical ball groove and a ball return crossover channel, the method comprising the steps of: placing a master model ball nut within a container, the model ball nut ha

A method of pour molding a one-piece plastic ball nut for a ball nut and screw assembly, the ball nut have formed therein an internal helical ball groove and a ball return crossover channel, the method comprising the steps of: placing a master model ball nut within a container, the model ball nut having a cylindrical body with inner and outer cylindrical walls and an opening formed axially through the body, the inner cylindrical wall having an internal helical ball groove, with turns connected by an internal crossover channel, formed therein for carrying a train of balls, the master model ball nut cylindrical body being a metal body provided with a radial opening formed in its outer wall which intersects the longitudinal axis of the nut and two adjacent turns of the helical ball groove, and there being a plastic insert provided in the radial opening which has a crossover channel internally formed therein to provide a ball path which interconnects the two adjacent turns of the helical groove; adding a silicone rubber material to the container until the material covers the outer cylindrical wall of the master model ball nut and fills the axial opening thereof; curing said silicone rubber material; removing the master model ball nut from the cured silicone rubber material so that said silicone rubber material forms a unitized resilient and slippery imprint mold for said one-piece ball nut, the unitized imprint mold having a cylindrical wall and an upstanding cylindrical core integrally joined to the cylindrical wall, the wall and the core defining a cavity between them; filling the cavity of the unitized imprint mold with a plastic resin; allowing said resin to harden to form an all plastic ball nut with a helical ball groove and crossover channel formed therein; and removing the plastic ball nut from the imprint mold to clear said imprint mold so that another plastic ball nut can be molded therein.