US1993182A

US1993182A - Hydraulic expansive reamer

Info

Publication number: US1993182A
Application number: US688112A
Authority: US
Inventors: James J Santiago
Original assignee: Individual
Current assignee: Individual
Priority date: 1933-09-05
Filing date: 1933-09-05
Publication date: 1935-03-05
Anticipated expiration: 1952-03-05

Description

March 5, 1935.

J. J. SANTIAGO HYDRAULI C EXPANS I VE BEAMER Filed Sept. 5, 1933 Eig. 2

and may be considered primarily as a valve member, although it may also perform as a pressure head, as will be pointed out. Lower head 32 operates in a liner 33 which forms the lower reduced part of the cylinder bore; this head carries packing 34 and fits the liner bore closely. The liner rests at its lower end on body shoulder' 33a, and a compression spring 35 rests on the upper endof the liner and pushes upwardly on upper head 30 to move the plunger upwardly and normally to hold it in its upper position, (Fig. 1) .v

In this position of the plunger cutters 12 are collapsed; when the plunger moves down the cutters are expanded.

In the normal position of Fig. 1 lower plunger head 32 covers the port 16a where passage 16 communicates with the cylinder bore. The long skirt 30h of upper head 30 lies above the relief port 40 such a distance that preferably that port is not covered by head 30 until about the time port 16a is opened by head 32. The drawing shows such relative positions of the ports that port 40 begins to close as port 16a begins to open; it is preferable that the two ports be not fully open together.

When uid pressure from the drill pipe is applied to the plunger in the position of Fig. 1, that pressure, acting on -the lower head 32 causes the plunger to move down, and to expand the cutters, under the full fluid pressure relieved only by the small port 40. The action of expansion is therefore positive, and under almost full pressure, until circulation port 16a is opened. Port 16a (passage 16) is of a size to allow relatively free circulation from the cylinder bore, but is smaller than the passage through the drill pipe (indicated at 41), so that sufficient back pressure is set up in the cylinder still to force the plunger down. And, additionally, there is some pressure exerted downwardly on upper head 30, although the passages 30a have a larger area thanpassage 16 and the back pressure above head 30 is therefore smaller than that on lower head 32. The back pressure on head 30 may be increased by making openings 30a smaller; they may be made in total area as small as that of passage 16;` but I prefer to keep them relatively large to minimize wear 1ianddto keep higher the back pressure on the lower In any case, the pressure on the lower head after port 16a opens, is sufficient to cause complete cutter expansion. Port 16a does not open until the cutters are well toward the fully expanded position of Fig. 2; the dotted lines show cutter positions with the port about half uncovered. At this time relief port 40 is closed or closing; and, the cutters being then far enough out to take a biting engagement with vthe wall of the hole, the fluid pressure on the plunger and the upward thrust of the formation on the cutters as the tool is lowered, cause the completion of positive expansion. Port 16a may be lowered if desired to a point where'the cutters are substantially completely expanded when the port is uncovered, but I prefer to have it uncovered and fluid circulation to the cutters begin, at about the time the cutters reach the position shown and begin cutting more or less fully.

On relief of pressure the spring immediately moves the plunger up and collapses the cutters.

Relief port 40 is then open` and allows drainage of fluid from the drill pipe as it is raised from the hole. A relatively small port at 40 suffices for drainage-a port much smaller than pipe passage 41 or circulation passage 16; so that port 40,

to care for drainage, does not have to be largefV enough to relieve any considerable fraction of' the pressure in the cylinder. And the size of port 40 may be changed to suit differing situations; it may be enlarged if work is being done in soft strata where expansion is easy; it may be reduced where expansion is difficult. Provision of port 40 in the removable bushing 40a facilitates such change by substitution; and the bushings may be of hardened steel to minimize wear of the orifice. And whenever that port becomes Worn by the fluid flow, the bushing may be replaced by a `new one. In cases where expansion is exceptionally difficult a solid plug may be substituted for the bushing so that full unrelieved pressure is then exerted on the plunger. And the suggested lower placement of port 16a provides for a longer application of that full pressure. I prefer, however, to use a bushing with at least a small port 40 wherever possible, to provide for drainage.

I claim:

1. In an hydraulic expansive tool, a body with a cylinder therein, an expansively movable cutter on the body, a plunger movable in the cylinder, connected to the cutter to move it and exposed to fluid pressure from the drill pipe to which the body is connected, a circulation port leading from the cylinder and discharging from the body, and a relief port leading from the cylinder, said circulation port arranged to be opened by movement of the plunger in cutter expanding direction, and said relief port being closed by the same movement of the plunger.

2. In an hydraulic expansive tool, a body with a cylinder therein, an expansively movable cutter on the body, a plunger movable in the cylinder, connected to the cutter to move it and exposed to fluid pressure from the drill pipe to which the body is connected, a circulation port leading from the cylinder and discharging from the body, and a relief port leading from the cylinder, said circulation port arranged to be opened by movement of the plunger in cutter expanding direction, and

said relief port being closed by the same movement .i

iid

on the body, a plunger movable in the cylinder,

connected to the cutter to move it and exposed to uid pressure from the drill pipe to which the body is connected, a circulation port leading from the cylinder and discharging from the body, and a relief port leading from the cylinder, said circulation port arranged to be opened by movement of the plunger in cutter expanding direction, and said relief port being closed by the same movement of the plunger, and said relief port being formed in a removable and substitutable bushing whereby the size of the relief port may be adjusted.

4. In an hydraulic expansive tool, a body with a cylinder therein, an expansively movable cutter on the body, a plunger movable in the cylinder, connected to the cutter to move it and exposed to fluid pressure from the drill pipe to which the body is connected, a circulation port leading from the cylinder and discharging from the body, and a relief port leading from the cylinder, said circulation port arranged to be opened by movement of the plunger in cutter expanding direction, said relief port being closed by the same movement of culation port, and said relief port being formed in a removable and substitutable bushing whereby the size of the relief port may be adjusted.

5. In an hydraulic expansive tool, a body with` -a cylinder therein whose upper end'is in communication with the drill pipe to which the body is attached, an expansively movable cutter on the body, a plunger movable in the cylinder and connected to the cutter to move it, the plunger having a lower head tting the cylinder and an upper passaged head also fitting the cylinder, a circulation passage leading from the cylinder at a point to be uncovered by the lower head on downward movement of the plunger, and a relief port leading from the cylinder at a point to be covered by the upper head on downward movement of the plunger.

6. In an hydraulic expansive tool, a body with a cylinder therein whose upper end is in communication with the drill pipe to which the body is attached, an expansively movable cutter on the body, a plunger movable in the cylinder and connected to the cutter to move it, the plunger having a lower head tting the cylinder and an upper passaged head also tting the cylinder, a circulation passage leading from the cylinder at a point to be uncovered by the lower head on downward movement of the plunger, and a relief Yport leading from the cylinder at a point to be covered by the upper head on downward movement of the plunger at a time not later than the uncovering of the circulation passage.

7. In an hydraulic expansive tool, a body with a cylinder therein whose upper end is in communication with the drill pipe to which the body is attached, an expansively movable cutter on the body, a plunger movable in the cylinder and connected to the cutter to move it, the plunger having a lowerhead tting the cylinder and an upper passaged head also fitting the cylinder, a circulation passage leadingfrom the cylinder at a point to be uncovered by the lower head on downward movement of the plunger, and a relief port leading from the cylinder at a point to be covered by the upper head on downward movement of the plunger, said relief port being formed in a bushing whereby its effective size may be adjusted.

JAMES J. SANTIAGO.