Patent ID: 7314101

Claim:
An inner core barrel head assembly for releasably latching in a latch seat provided in a drill string, said assembly comprising: an upper hollow latch body; a plurality of latching elements retained in said latched body; a hollow locking sleeve disposed within said upper latch body, said locking sleeve having a latching surface of a first outer diameter and a release surface of a second outer diameter less than said first outer diameter, said locking sleeve axially moveable relative to said upper latch body between a locking position and a release position, said locking position characterised by said latching elements being in abutment with said latching surface forcing said latching elements to move radially outwards where said latching elements can engage said latch seat to lock said assembly to said drill string, and said release position characterised by said release surface juxtaposed radially inside of said latching elements to allow said latching elements to move radially inwards out of engagement with said latch seat; an internal passage constituted in part by said hollow locking sleeve through which fluid can flow when said inner core barrel assembly is tripped through said drill string; and a first valve for opening and closing said internal passage, said first valve comprising a first moveable stop located in the internal passage and a first seat formed on an up hole end of the locking sleeve wherein the first moveable stop closes the internal passage when seated on the first seat to block flow of fluid in a down hole direction.