Safety lock for a linear fluid pressure actuator

Claim 1

For use in combination with a hydraulic ram having a cylinder body, a piston rod extendable and retractable through one end of said cylinder body, a clevis on the outer end of said piston rod, and a connecting pin extending between the legs of said clevis and having portions extending outwardly from the outer sides of said legs, a device for preventing retraction of the piston rod from its extended position comprising: a rigid, elongated spacer of generally U-shaped cross-section adapted to fit over the extended piston rod and having inner and outer ends engageable, respectively, with said cylinder body and said clevis, said spacer having a bight portion normally disposed adjacent to the piston rod, and a pair of generally parallel sides extending on opposite sides of said rod; and means for mounting said spacer on said clevis for swinging movement to an inoperative position away from said piston rod including a pair of arms fixed to the sides of said spacer and extending along opposite outer sides of said clevis, said arms having apertures therein receiving the portions of said pin extending outwardly from said clevis, said apertures being larger than said pin to permit limited movement of said spacer relative to said clevis in the direction of elongation of the spacer, said spacer being disposed between its extremes of movement relative to said clevis when the outer end of said spacer is engaged with said clevis.