expand the collet heads 22 apart as they jump up on raised groove 40 this is the position shown in fig5 in this position the mandrel has moved up enough to open the valve not shown and the mandrel 10 is precluded from moving down because collet heads 22 will not clear no go 34 when on raised groove 40 at the same time spring 42 keeps the mandrel 10 from moving uphole as the spring force keeps mandrel 10 up against a stop not shown the lock l in the preferred embodiment is automatically triggered as the downhole valve goes into the open position the lock l can be defeated by inserting a tool that extends the mandrel 10 by shifting dogs not shown in a manner that lets the lower end of mandrel 10 not shown be forced down to close the valve while allowing the portion of mandrel 10 shown in fig5 be biased up by spring 42 with collet heads 22 moving relatively to sleeve 26 so that the collet heads 22 go into upper groove 36 so that the position of fig1 is resumed the downhole valve can now be cycled the 12 times mentioned before to get it to open and lock open as described above the release procedure is illustrated in an u2018 rb u2019 valve shown in fig6 fig6 is a split view showing the u2018 rb u2019 valve locked open on one side and at the instant.