Two stage cementing collar

Claim 1

In a cementing collar comprising an elongated vertically extending tubular body having a central bore extending longitudinally therethrough and means for connecting said body in a pipe string, at least one radially extending port communicating between the exterior and interior of said tubular body, an elongated tubular sleeve axially received within said bore of said tubular body, said sleeve having a central bore extending therethrough and with at least one radially extending orifice communicating between the exterior and interior of said sleeve, first securing means for releasably securing said sleevE in a closed upper position within said body, said upper position being such that said orifice and said port are completely out of register when in the upper position, first releasing means received within said body for releasing said first securing means such that said sleeve takes an intermediate position with said port and said orifice in overlapping registration for establishing communication between the interior of said sleeve and the exterior of said body, second securing means engaged with a first groove in the exterior of said sleeve and engagable with a circumferential groove within the interior of said body for maintaining said sleeve and said body in said intermediate position to maintain the open condition, second releasing means received within said body for releasing said second securing means, a hollow cylindrical member axially slidable within said sleeve and releasably secured in inoperative relationship with said second securing means by third securing means maintaining said inoperative relationship by relative positioning of said member and said sleeve, the improvement comprising: said member having a substantially cylindrical outer surface with a plurality of axially elongated radially outwardly extending elements thereon said elements having downwardly tapering ramp surfaces thereon which are parts of a conical surface extending upwardly and outwardly at least to the full diameter of said sleeve, said sleeve having upwardly extending a plurality of circumferentially spaced separate portions receivable between said outwardly extending elements of said member, said ramp surfaces being engageable with said second securing means by axial movement of said member to bias said second securing means radially outwardly from the said groove in said outer surface of said sleeve to release said sleeve for downward movement into a second closed position wherein said port and said orifice are completely out of register.