Lock mechanism for telescopic hold open rod

A telescopic hold open rod having an axial centerline that extends between a first axial end and a second axial end, comprising:

• a control sleeve (CS) having a first CS cavity section defined by a first CS inner radial surface, a second CS cavity section defined by a second CS inner radial surface, a CS channel disposed in the second CS inner radial surface, and a pin extending radially inward from the second CS inner radial surface;
• an outer cylinder (OC) having an OC inner cavity, an OC inner radial surface, an OC outer radial surface, an OC axial end wall, a plurality lock ball apertures extending between the OC inner radial surface and the OC outer radial surface, and a pin guide slot configured to receive the pin, wherein the outer cylinder extends axially within the first CS cavity section and the second CS cavity section;
• a plurality of lock balls, each configured to pass through a respective lock ball aperture;
• a lock sleeve (LS) having an LS bore, wherein a portion of the lock sleeve is disposed in the OC inner cavity;
• a piston having a first section and a second section, and a piston shoulder surface that extends radially between the first section and second section, wherein the first section and the second section extend axially within the OC inner cavity, and the second section extends axially within the LS bore;
• a piston head (PH) having a PH outer radial surface, a first PH channel disposed in the PH outer radial surface, and a piston bore, wherein the first PH channel extends around a circumference of the PH outer radial surface, the piston bore is configured to receive the first section of the piston, and the piston head is disposed within OC inner cavity;
• a release spring disposed between the OC outer radial surface and the first CS inner radial surface and configured to bias the control sleeve toward the first axial end;
• and
• a lock spring disposed between the OC outer radial surface and the lock spring and configured to bias the lock sleeve toward the second axial end.