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. 13, 1978
Filed:
Apr. 30, 1976
Kazuo Suzuki, Katsuta, JA;
Hiroyuki Kataoka, Nakamachi, JA;
Hitachi, Ltd., , JA;
Abstract
A speed command voltage is generated which increases in proportion to the lapse of time so as to increase the speed of an elevator car at a constant acceleration after starting. Another speed command voltage is generated which decreases with the reduction in the distance between the position of the travelling elevator car and the target floor position so as to decrease the speed of the elevator car at a constant deceleration. The speed patterns provided by these speed command voltages are joined together to provide a continuous speed pattern for the elevator car instructed to travel to arrive at the target floor. In order to ensure shock-free operation of the elevator car at the joint between these speed command voltages, the speed command voltages in accordance with respective speed patterns for use in acceleration and deceleration are compared with each other, and the increase in the speed command voltage for acceleration is ceased when the difference therebetween attains a predetermined value. The speed command voltage is maintained constant at this level to provide a constant-speed command voltage. Then, the constant-speed command voltage and speed command voltage for deceleration are applied to a lower-level signal passing circuit, in which two input signals are compared with each other and the lower level signal of them only is passed, to obtain a completely continuous speed pattern for the elevator car. A reference command voltage is generated, which increases up to a predetermined level with the increase in the speed command voltage for acceleration, and the rate of increase of which decreases gradually upon attainment of such a level. This reference command voltage is used to maintain always constant the length of time of this constant-speed command voltage. The increase in the speed command voltage for acceleration is ceased to obtain the constant-speed command voltage when the difference between the speed command voltage for acceleration and the speed command voltage for deceleration is reduced to a value less than that of the reference command voltage.