Patent ID: 8333255

Claim:
A downhole tool assembly configured to be tripped through a drill string, comprising: a core barrel head assembly comprising an outer sleeve; a non-dragging latching mechanism configured to be tripped into a drill string without dragging against an interior surface of the drill string, wherein the latching mechanism is configured to selectively move between an engaged position and a retracted position, wherein when in said engaged position, at least a portion of said latching mechanism extends outward of said outer sleeve; and a detent mechanism configured to selectively lock said latching mechanism in said retracted position as said core barrel head assembly is tripped into the drill string, wherein said detent mechanism comprises: a first pair of opposed recesses extending into an inner surface of said outer sleeve; a second pair of opposed recesses extending into said inner surface of said outer sleeve, wherein said second pair of opposed recesses is spaced distally with respect to said first pair of opposed recesses; a pair of balls configured to be selectively biasably received within said first pair of opposed recesses when said latching mechanism is in said retracted position and within said second pair of opposed recesses when said latching mechanism is in said engaged position; and a spring positioned therebetween said pair of balls and configured to selectively bias said pair of balls outwardly toward the one pair of the respective said first or second pairs of opposed recesses.