The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 06, 1981
Filed:
Aug. 13, 1979
Daniel A Worsham, San Jose, CA (US);
Pacific Western Systems, Inc., Mountain View, CA (US);
Abstract
In a lead screw drive, such as that used in a lightweight lathe or milling machine for driving the workpiece relative to the cutting tool, the core of a drive nut is made of a material having a relatively low melting temperature, such as babbitt metal or a relatively rigid thermoplastic material. The low melting point material is contained within a nut housing as of steel. The openings in the nut housing for passage of the lead screw are scaled in a fluid type relation by means of elastic sealing members as of silicone rubber having a melting point above that of the relatively low melting point core portion of the nut. An electrical heating cartridge element is contained within the nut housing in good thermally conductive relation with the low melting point core material. When backlash develops due to wear of the core material of the nut, the heating element is energized under control of a controller to melt the core of the nut so that the core material is caused to flow and to reform itself to the thread profile of the lead screw. A thermocouple disposed in thermally conductive relation with the core senses the temperature of the core. A controller responsive to the sensed temperature, causes the nut to cool in accordance with a predetermined sequence of time and temperature and to be run in on the lead screw while lubricant is caused to be sprayed on the lead screw.