US 5,293,811 A · Missile control fin actuator system

Abstract

A control fin actuator (28) for a guided missile (20) includes a pressure actuator (40) having a slidable piston (44) inside a housing (42). Rolling diaphragm seals (50, 56) of the top piston face (46) and the bottom piston face (48) to the inside wall of the housing (42) divide the interior of the housing (42) into at least two chambers (54, 58). The rolling diaphragm seals (50, 56) eliminate sliding friction as the piston (44) moves within the housing. The two chambers (54, 58) are controllably pressurized to slide the piston (44) within the housing (42), thereby moving a push rod (78) attached to the piston (44) and extending out of the housing (42). The push rod (78) is connected to a missile control fin output shaft (24) by a taut band connector (80) that avoids backlash. A magnet (86) may be positioned adjacent to the push rod (78) to induce eddy currents in the push rod (78), thereby providing a damping force that increases with increasing rate of movement. Pressure in the control chamber (54) is achieved by operating the inlet valve (70) and the exhaust valve (72) in response to feedback information from a rotary position sensor (29), a linear position sensor (88), and/or pressure sensors (90, 92).

Claims15

Dependent claims

A missile control fin actuator that produces rotation of a control fin output shaft, comprising:

a pressure actuator, including
a housing,
a compound piston slidable within the housing, the compound piston having a first face piece and a second face piece slidable relative to each other,
a first rolling diaphragm seal between the first face piece and the housing wall, thereby defining a first pressure chamber of the pressure actuator between the first face piece and the housing,
a second rolling diaphragm seal between the second face piece and the housing wall, thereby defining a second pressure chamber of the pressure actuator between the second face piece and the housing,
a push rod connected to the first face piece and extending out of the housing, and
a push sleeve connected to the second face piece and extending out of the housing, the push sleeve overlying the push rod;
a third rolling diaphragm seal between the push sleeve and the housing, completing the seal of the second pressure chamber;
means for controllably pressurizing the first pressure chamber and the second pressure chamber to cause the first face piece and the second face piece to slide within the housing and relative to each other;
and
means for connecting the push rod and the push sleeve to a control fin output shaft.

8 more elements

Dependencies are inferred from the claim text.

Missile control fin actuator system

Life of this patent

Missile control fin actuator system

Life of this patent

Abstract

Claims15