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:
May. 26, 1992
Filed:
Apr. 20, 1990
Martin A Keane, Arlington Heights, IL (US);
William H Englehardt, Wood Dale, IL (US);
Life Fitness, Franklin Park, IL (US);
Abstract
A control for a DC motor coupled to a user interface to provide a counterforce which simulates a weight stack in an exercise machine. The control includes a position transducer coupled to the motor to provide a signal proportional to the displacement of the user interface. In one embodiment a circuit is provided to generate a control signal which follows the displacement signal when it is less than a maximum torque signal, the control voltage following maximum torque signal when it is less than the displacement signal. In a second embodiment a microprocessor control unit is responsive to the displacement signal to provide a control signal for the motor which starts increasing from a first value when the user interface is displaced an initial amount and which continues gradually increasing to a maximum value as the user interface is moved through a given displacement from the initial displacement. The control signal is used to soft start the motor such that the counterforce provided by the motor simulates a weight stack supported by a spring over small displacements of the user interface.