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. 05, 1981
Filed:
Jul. 16, 1979
Applicant:
Inventor:
Ned E Dammeyer, New Bremen, OH (US);
Assignee:
Crown Controls Corporation, New Bremen, OH (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B66F / ; B60K / ; G05B / ; H02P / ;
U.S. Cl.
CPC ...
187 / ; 180170 ; 180271 ; 318333 ; 318652 ;
Abstract
A speed control circuit is provided for a lift truck which is driven by an electric truck drive motor powered from a power source through a motor controller. The motor controller is responsive to a power control signal generated by summing a speed sensor signal, which is derived by comparing a tachometer signal with a speed selection signal. A fork height sensor provides a fork height signal which is used to limit the maximum level of the speed control signal. A safety circuit monitors operation of the speed control circuit and disconnects the circuit from the motor controller upon occurrence of a malfunction.