US2194257A - Ram with tapered wear plates - Google Patents

Description

March 19, 1940. H. ALLEN RAM WITH TAPERED WEAR PLATES Filed July 2, 1'93? 3 Sheets-Sheet 1 n A on fin m M Q 4 mm ATTORN EYE.

March 19', 1940. H. ALLEN 'RAM WITH TAPERED WEAR PLATES Filed Jul y 2, 1937 3 Sheets-Sheet 2 V HERBERTALLEN.

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March 19, 1940. H. ALLEN 2,194,257

RAM WITH TAPERED WEAR PLATES Filed July 2. 193'? s Sheets-Sheet s HERBERT ALLEN Patented Mar. 19, 1940 PATENT y OFFICE 2,194,257 RAM wrrn TAPERED WEAR PLATES Herbert Allen, Houston, Tex., assignor to Cameron Iron Works, a corporation Application July 2, 1937, Serial No. 151,655 4 Claims. ci. 251-51 "The invention relates to a blowout preventer of the type which is attached to well heads wherein a closure is to be made across the well opening.

It is one of the objects of the invention to provide a blowout preventer construction wherein the rams of the blowout preventer are adapted to close about a pipe in the well bore and to maintain a seal about the pipe even though the pipe is subjected to rotation for long periods of time.

Another object ofthe invention is to provide a ram construction for blowout preventers wherein a packing and wear plates are provided in such a manner that wearing away of the packing material will be automatically compensated for by displacement of additional packing material to the wearing position by the movement of the wear plates. 1 I

Another object of the invention is to provide a blowout preventer ram with a tapered groove across its front face, which is arranged to receive a packing assembly in such a manner that when the assembly is forced into the groove some;

of the packing material will be displaced and extruded forwardly to maintain a seal with the pipe in the well bore.

Another object of the invention is. to provide 1 tapered plates on a blowout preventer packing so that as the wear increases the amount of packing material displaced will-be increased. Other and further objects of the invention will be readily apparent when the following description is considered in connection with the accompanying drawings, wherein:

' Fig. 1 is a side elevation of the blowout preventer with certain of the parts shown in section and the rams in open position.

Fig. 2 is a side elevation similar to Fig. 1 but illustrating the rams as being closed about a pipe in order to form a seal therewith.

Fig. 3 is a. perspective View of the ram body and illustrating the grooves and recesses therein which are to receive the packing assembly. I

Fig. 4 is a perspective view of the packing assembly. I

In Fig. l the blowout. preventer body is -illus-' trated generally at 2 and comprises a' construction which is provided with a vertical passage 3 therethrough; which is the passage from the well bore. The preventer is attached to the well head passage 3. These chambers are arranged to movably receive the ram members 9 and Ill, these ram members being identical in construction so that the description of one of them should suflice. v

The chambers I and 8 are closed at their outer ends by a bonnet such as l2, which is held in position by the bolts l3. This bonnet carries 3 a stem ll which is enclosed by a stufling box l5 and is rotatable in the bonnet, but is restrained from longitudinal'movement by virtueof the retainer rings l'l, one of which is positioned on each side of the flange i8 which is formed on the stem. The inner end of the stem is threaded at 20 and in this manner engaged in the'cap 2! which forms a portion of the ram I0.' It seems obvious that rotation of the stem I will cause the ram to move to and fro to open and closed position.

Particular attentioh is directed to the construction of the ram body II) as best seen in Fig. 3. This body is made up of a head25 and a shank 26. These two parts are preferably in the form of an integral casting or forging and it will be observed that the shank 2B is of less diameter than the head 25 and that a. shoulder 21 defines these differences in diameter. While this ram construction is shown as circular it is to be understood that it may take any other desired configuration, so long as it embodies the spirit of the invention. The, forward face 29 of the ram is provided with agroove 30. This groove is somewhat tapered and extends entirely across the front face 29 of the rampthe widestIportion of the groove being at the forward end. The base 3| of the groove is shown as being curved and at its end it merges with the side recesses 32, one of which is shown on each side of the head 25. These recesses 32 extend rearwardly along the side of thehead to' the shoulder 21.

The forward face 29 is vertically grooved with. the semi-circular openings 33 which are arranged to pass about a pipe in thewell bore. openings 33 will be made of different sizes of course to accommodate different diameters of pipe. on the other hand ifthe preventer is to be used when there is no pipe in the well both these recesses 33 will be omitted and the face 29 i will extend in a single plane across the. front of the ram.

The top and bottom of the ram may be provided with a. cutaway portion 34, so as to provide a fiat face 35 surrounding the opening33.

These This arrangement is provided so that a coupling on the drill pipe 36 may be deposited upon the face so as to support the weight of the string of pipe on the blowout preventer, if desired. In event of excessive pressures and movement of the drill pipe the collars can come in contact with this face 35 and there is a tendency to form a seat in this way for the tool joint or coupling on the pipe. A small opening 31 on the inner face of each of the recesses 32 is provided in order to receive a pin which may be formed upon the inner surface of the packing member so as to assist in holding the packing assembly in position.

The shank 26 is illustrated as cylindrical but, of course, if the head 25 is of a different configuration the shank may or may not be made of this same configuration.

The packing assembly is illustrated in perspective in Fig. 4 and is made up of a packing body which is of resilient material, such as rubber or other suitable substance which will flow under pressure to some extent, so that a pressure applied at one point thereof will be distributed throughout the material to provide a seal of uniform pressure at all points, This body of packing material is of a peculiar configuration in order that it may be deposited in the groove 30 and comprises a flat body portion 4i which is thickened at 42 near the rear end thereof, the beveled shoulders 43 defining the thick from the thin areas. The rear end 45 may be curved to fit the configuration of the base 3!. The thin portion 4| is preferably of uniform -thickness throughout its length and width and may be cut away at 41 to conform to the size and shape of the openings 33 which are to receive the pipe 36. Extending rearwardly from the body 40 are the legs 48, one of which is positioned at each side at the rear of the body. These legs are of rectangular configuration except for the outer periphery 49 which may be curved to conform to the periphery of the head 25.

Particular attention is directed to the wear plates 50 and 5f which are positioned on the top and the bottom of the packing member in order to complete the assembly. These wear plates are deposited on each side of the thin portion 4land may be vulcanized or otherwise aflixed to the rubber so that they are retained thereby and, will float upon the rubber. Each of these plates has a thickened forward end 53 and the plate gradually tapers away toward the rear which is the thinnest part thereof. A beveled face 54 on the inside rear of each plate is formed to cooperate with the beveled face 43 on the packing.

When the packing assembly 40 is positioned in the ram it will completely fill the groove 30 and the legs 48 will be positioned in the grooves 32. As seen in Figs. 1 and 2. the packing assembly is of such size that it will project from the forward face 29 of the ram so that the front face of the packing material and the front faces 6| of the plates 50 and 5| will all extend ontwardly into the opening 3 in front of'the ram. This is desirable because when the rams are moved to closed position as shown in Fig. 2 it is intended that these front faces will abut against the pipe 36 in order to form a seal.

As the stem I4 is rotated the ram member will be moved forwardly and forced into engagement with the pipe. This pressure is, of course, trans ferred from the pipe to the ram through the face II. It seems obvious that due to the flexibility of the packing material that this pressure will be transferred through the packing material so that it will be expanded against all of the faces of the groove 30 and transferred along the legs 48 to the grooves 32. The outer periphery of the packing will, of course, form a seal against the inside surface of the cylinder 8, so that a complete seal is formed in this manner transversely of the housing 2.

In event the drill stem is rotated and the friction caused by the pressure of the packing against the surface of the pipe results in wearing away of the face ill where it contacts the pipe, then, of course, there will be a tendency for the packing material to flow forwardly to replace the material which has been worn away. In order to assist in this movement of the packing material the wear plates 50 and-5| of course are constantly applying pressure to the thickened portion 42 of the packing material. There is, of course, a tendency for the entire ram Hi to move forward and inasmuch as the wear plates 55 and 5| remain stationary, then the packing material from the thickened portion 42 will move forwardly around the beveled face 54 of the wear plates and be extruded forwardly between the plates in order to compensate for wear.

The wear plates 50 and 5| being thicker at their forward ends tend to be forced toward each other as the ram advances, due to the tapered faces of the groove 30. In this manner the greater the wear and the greater the movement of the ram toward the pipe, the greater volume of packing material will be displaced because of the tapered construction of the groove 30 and the tapered construction of the plates 50 and 5|.

In order that a seal may be formed about the head 25 of the rams an annular packing ring 10 is deposited against the shoulder 21 and is arranged to abut the ends H of the legs 48. This ring 10 is held in position by the end 12 of the cap 2|, this cap in turn being clamped in position by the bolts 13 which pass through the cap and are threaded into the end of the shank 26. The ram is held in n0n-rotatable position by the cooperating rib and groove at 14 in the bonnet l2.

It seems obvious that the cap 2| may be clamped in position with any desired pressure being applied to the ring 1| so that when the packing assembly abuts against the pipe the additional pressure transmitted through the legs 48 will tend to form a peripheral seal about the rear of the head 25 so that a complete seal will be formed at each side of the blowout preventer.

What is claimed is:

l. A packing assembly for valves comprising a body of resilient material, side legs thereon, the forward portion of said body being of reduced thickness, a tapered shoulder joining the thin and thick portions of the body, and a rearwardly tapering metal wear plate disposed on each side of the thinner area.

2. A packing assembly for valves comprising a body of resilient material, side legs thereon, the forward portion of said body being of reduced thickness, a tapered shoulder joining the thin and thick portions of the body, and a metal wear plate disposed on each side of the thinner area,

said-plates being tapered with the thicker portion at the front.

3. A device adapted to abut an object to seal an opening against pressure, a packing carried by the device, means on the packing disposed 60 abut and confine the packing, means to force the device toward the object to compress the packing andestablish a pressure in the confined packing of a value greater than that in the opening to be closed, said first means comprising tapered plates.

4. A device adapted to abut an object to seal an opening against pressure, a packing carried by the device, means on the packing disposed to abut and confine the packing, means to force the device toward the object to compress the packing and establish a pressure in the confined packing of -a value greater than that in the opening to be closed, said first means compacking.

. HERBERT ALLEN.

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