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:
Jun. 14, 1994
Filed:
Jul. 02, 1992
Michel A Pierrat, Boulder, CO (US);
Other;
Abstract
A reversible drive system is provided that is particularly adaptable to low-power drives in which precision mechanical control must be obtained with the lowest possible cost and the highest reliability. The drive is described as incorporated in a lead screw drive in which a control nut reciprocates between two fixed positions. At the end of the movement in one direction, the control nut strikes a fixed abutment that stops the motion thereby increasing the load on the drive motor and causing an increase in the current drawn by the motor. This increase in current is utilized to disconnect the power source from the motor. In such systems, in particular where there is a large reduction in the speed between the motor and the driven object, as with the use of a lead screw drive arrangement, it is desirable to store energy at the end of each stroke that is available to decrease the starting torque required to reverse the direction of motion. To provide additional starting torque, the motor coupling includes a lost-motion coupling by which no significant load is placed on the motor until the output shaft of the motor, or an element driven by the motor, has moved through some fraction of a revolution. For most applications a lost-motion arrangement equivalent to about one hundred eighty degrees of motion is practical.