Pneumatic actuator for a stores carriage and ejection system

A stores carriage and ejection system which is operable to carry the stores on an aircraft in flight and to eject those stores from the aircraft on demand, comprising:

• at least one pneumatic actuator having an actuating member which includes an actuating rod portion which extends from a differential area piston having two piston portions, the cross-sectional areas of which are different, the differential area piston being slidable in a closed chamber which is filled with gas under pressure when the actuator is operated and from which the actuating rod portion projects, one of the piston portions being slidably engageable in a cavity which is formed in an end wall of the closed chamber and which has a cross-section similar to that of said one piston portion, means operable when said one piston portion is engaged in said cavity to apply gas under pressure to a surface of said one piston portion which is formed at an end thereof remote from the other piston portion whereby to apply an actuating thrust to the actuating member and to displace said one piston portion from the cavity so that the greater cross-sectional area of the differential area piston is subjected to the gas under pressure within the closed chamber, and releasable hold-back means operable to hold the piston in the location that is furthest from the location of the piston at which the volume within the chamber is at its maximum, wherein the chamber is a cylinder closed at one end and separated by said end wall from a second chamber to be charged with compressed gas in use of the actuator, the end wall having an aperture that serves as said cavity, the two piston portions form a stepped piston and the actuating rod portion is a piston rod, the stepped piston being mounted at one end of the piston rod by the one piston portion, wherein the piston rod extends through the aperture and the second chamber and has a cross-sectional area smaller than that of the aperture that slidably receives said one piston portion of the stepped piston, the releasable hold-back means being operable to hold the piston adjacent to the end wall with said one piston portion received in the aperture.

A stores carriage and ejection system which is operable to carry the stores on an aircraft in flight and to eject those stores from the aircraft on demand, comprising:

• at least one pneumatic actuator having an actuating member which includes an actuating rod portion which extends from a differential area piston having two piston portions, the cross-sectional areas of which are different, the differential area piston being slidable in a closed chamber which is filled with gas under pressure when the actuator is operated and from which the actuating rod portion projects, one of the piston portions being slidably engageable in a cavity which is formed in an end wall of the closed chamber and which has a cross-section similar to that of said one piston portion, means operable when said one piston portion is engaged in said cavity to apply gas under pressure to a surface of said one piston portion which is formed at an end thereof remote from the other piston portion whereby to apply an actuating thrust to the actuating member and to displace said one piston portion from the cavity so that the greater cross-sectional area of the differential area piston is subjected to the gas under pressure within the closed chamber, and releasable hold-back means operable to hold the piston in the location that is furthest from the location of the piston at which the volume within the chamber is at its maximum, the releasable hold-back means including an external latch.