US 4,356,900 A · Drive system

Abstract

An improved heavy duty motor clutch drive system is disclosed which includes a motor adapted to be drivingly connected to apparatus to be driven by means of a clutch unit of the oil shear type which may be selectively actuated by application of fluid pressure. Improved electrically actuated control valve means are provided for controlling the application of actuating fluid pressure to the clutch unit and includes associated control circuitry for operating the control valve so as to accelerate the driven apparatus in a predetermined manner. Additionally, in some applications a plurality of such drive systems may be utilized to drive a common apparatus in which case the clutch actuating controls may be interconnected so as to provide progressive predetermined delay actuation of the various clutch units. Safety override means are also incorporated into the control circuitry which are designed to deactuate the clutch unit so as to disconnect the motor from the driven apparatus in response to abnormal operating conditions.

Claims27

Dependent claims

A drive system comprising:

driven means;
motor means;
fluid actuated clutch means selectively actuable to drivingly connect said motor means to said driven means;
and
control means for controlling the actuation of said clutch means, said control means including
pressure relief fluid control valve means;
and
drive means operatively connected to control actuation of said valve means, said drive means being operative to progressively move said valve means from a first position to a second position at a first predetermined rate and to move said valve means from said second position to a third position at a second predetermined rate,
said valve means being operative to progressively increase actuating pressure to said clutch means whereby said driven means may be accelerated at a first rate during movement of said valve means at said first predetermined rate and at a second rate during movement of said valve means at said second predetermined rate.

6 more elements

In a drive system including driven means, motor means, fluid actuated clutch means operative to selectively drivingly connect said motor means to said driven means, valve means for selectively applying actuating fluid pressure to said clutch means and control means for controlling operation of said valve means, said control means comprising:

a stepping motor operative to drive said valve means through a predetermined number of steps so as to move said valve means between open and closed positions;
first circuit means connected to said stepping motor for driving said stepping motor through said predetermined number of steps in a first direction;
second circuit means connected to said stepping motor for driving said stepping motor through said predetermined number of steps in the second direction;
resetting circuit means operative to drive said stepping motor through said predetermined number of steps in one of said first and second directions upon energization of said control means;
low speed circuit means operative to control said first circuit means so as to drive said stepping motor through a portion of said predetermined number of steps in another of said first and second directions at a low speed whereby said valve means will operate to gradually apply actuating pressure to said clutch means so as to slowly accelerate said driven means;
and
high speed circuit means also operative to control said first circuit means so as to drive said stepping motor in said another direction and through the remaining portion of said predetermined number of steps at a higher speed whereby said valve means will operate to increase said actuating pressure applied to said clutch, said high speed circuit means being actuated in response to a predetermined sensed condition being achieved within said clutch.

4 more elements

Dependencies are inferred from the claim text.

Drive system

Life of this patent

Drive system

Life of this patent

Abstract

Claims27