US3024846A

US3024846A - Dual completion packer tool

Info

Publication number: US3024846A
Application number: US696652A
Authority: US
Inventors: Lonnie L Gage
Original assignee: Individual
Current assignee: Individual
Priority date: 1957-11-15
Filing date: 1957-11-15
Publication date: 1962-03-13
Anticipated expiration: 1979-03-13

Description

March 13, 1962 L.. L. GAGE DUAL. COMPLETION PACKER TOOL Filed Nov. 15, 1957 INVENTOR.

Lonnie L. Gag- EYQMW@ A TTORN lin- .n m Il Maw , Y A 4 V 3,024,845 Patented Mar. 13, 1962 ffice 3,024,846 DUAL COMPLETION PACKER TQQL Lonnie L. Gage, i707 Birch St., Duncan, Okla. Filed Nov. l5, 1957, Ser. No. 696,652 5 Claims. (Cl. 166226) This invention relates to improvements in packers for producing oil wells, and more particularly, but'not by way of limitation, to a dual packer apparatus for permitting dual or multiple completion of oil wells in order to produce well fluid from two or more fluid bearing formations.

Many oil well bores extend downwardly into the earth through more than one oil or gas bearing subsurface formation. It will be apparent that it is very desirable for purposes of economy to produce uid from all of the fluid bearing formations through one well bore in lieu of drilling additional well bores into each of the oil or gas bearing subsurface formations. However, due to governmental regulations, the several oil bearing formations must be produced separately, and may not be allowed to flow simultaneously. At the present time it is Very diflicult to obtain separate oil production from the multiple subsurface formations, and particularly when the fluid bearing sands are disposed at substantially great depths in the well bore, such as in excess of four thousand feet below the surface of the ground.

The most common method today for producing7 fluid from two or more oil bearing sands is to place a packer between the tubing and well casing within the well bore, and disposed between the producing sands. One of the oil sands may then be produced through the annular space between the well tubing and well casing, whereas the other oil sand may be produced through the well tubing itself. One disadvantage of this type of dual completion for oil wells is that paralin tends to accumulate on the inner walls of the well casing. It is very dillicult to remove the paraffin from the walls of the casing, and the accumulation of the paraflin not only interferes with the flow of the well fluid, but also greatly hinders the removal of the packer from the well bore when it is necessary to service the well for any reason.

The present invention contemplates a novel dual completion packer apparatus which provides for producing from multiple oil or gas sands entirely through the tubing, thereby eliminating any possibility of paraffin accumulation within the casing. Paran which may adhere to the inner walls of the tubing may be readily removed in any well known manner, such as by introducing a hot fluid into the tubing for melting the paraflin. This method for remoyal of paraffin is not practical for utilization in well casing.

The novel packer joint is adapted to be interposed within the well tubing string at substantially any desired depth within the well bore in order to produce fluid from multiple subsurface formations separately, regardless of the depth of the oil bearing formation. The novel tool comprises a pair of telescopically disposed tubular members which function in the manner of a slide valve for alternately producing fluid from the multiple subsurface oil sands. For example, in the event two vertically spaced oil bearing sands are present within the well bore, the novel packer joint may be interposed in the tubing string whereby one position of the tubular members will provide communication between the upper oil sand and the interior of the well tubing. Simultaneously, the lower oil sand is sealed or packed off whereby the uid contained therein cannot enter the well tubing. The Huid from the upper sand may thus be produced from the well as desired. When it becomes desirable to cease the flow of fluid from the upper oil sand, and begin the production from the lower o-il sand, thepacker tool may be positioned whereby communication is established between the lower sand and the interior of the tubing, while the upper sand is simultaneously sealed or packed off in order to stop the ow or production of the fluid thereinto. The fluid from the lower sand may then be produced from the well in any well known manner. The tubular members may be readily telescopically raised and lowered with respect to each other by raising or lowering the well tubing at the surface of the well in any well known manner.

It is an important object of this invention to provide a packer joint unit for permitting the dual completion of an oil well whereby multiple oil sands may be produced independently of each other from one well bore.

It is another object of this invention to provide a dual completion packer joint whereby a plurality of vertically spaced oil sands may be produced through the well tubing.

Another object of this invention is -to provide a dual completion packer joint for oil wells wherein a plurality of vertically spaced oil sand may be produced independently from each other through a single well bore.

A further object of this invention is to provide a novel packer joint for an oil well tubing string which may be easily positioned from the surface of the well for selectively producing well uid from a plurality of subsurface oil bearing formations.

It is a still further object of this invention to provide a packer joint for an oil well tubing string for a dual cornpletion of the Well whereby multiple oil bearing sands may be produced in a manner wherein the accumulation of parat-lin on the inner Walls of the well casing is substantially eliminated.

A still further object of this invention is to provide a dual completion packer joint for an oil well tubing string which is simple and efhcient in operation :and economical and durable in construction.

Other objects and advantages of the invention will be evident from the following detailed description, read in conjunction with the accompanying drawings, which illustrate my invention.

In the drawings:

FIGURE 1 is a broken vertical sectional view of the upper portion of the novel packer joint in a position providing for production from one oil bearing formation.

FIGURE 1A is a vertical sectional View depicting the lower portion of the tool shown in FIG. l.

FGURE 2 is a view similar to FIG. l with the novel tool in a position for providing for flow of fluid from a second oil bearing formation.

FIGURE 2A is a view similar to FIG. 1A and depicts the lower portion of the tool shown in FIG. 2.

Referring to the drawings in detail, reference character l@ generally indicates a dual completion packing joint adapted to be interposed within an oil Well tubing string (not shown). The packing joint shown herein is particularly designed and constructed for utilization with two vertically spaced oil or gas bearing formations (not shown). However, it will be apparent that the tool 10 may be lengthened and modied for use with more than two vertically spaced fluid bearing formations, if desired.

The packer tool 1d comprises an inner mandrel l2 slidably or telescopically disposed within an outer sleeve 14. The upper end i6 of the mandrel 12 is threaded to receive a suitable sub or tubular member 13 for a purpose as will be hereinafter set forth. The sub member 1S is provided with suitable threads Ztl at the upper end thereof for threaded connection with the oil well tubing string (not shown) in any well known manner. An inwardly extending circumferential shoulder 22 is provided in the tubular member 18 and spaced above the mandrel 12 to provide a seat for a suitable nipple member (not shown) in order to seal the tubing string from the flow of fluid when it is necessary to pull the tubing and the packer joint from the Well for any reason.

An upper stationary' packing sleeve 24 is provided between the inner mandrel 12 and the outer sleeve 14. The packing sleeve 24 is preferably constructed from a suitable packing rubber or may be constructed from suitable steel packing material when the unit or tool 10 is utilized under high temperature conditions. The packing sleeve 24 rests on an upper shoulder 26 of an inwardly directed circumferential lug member 2S provided on the inner periphery of the outer sleeve 14. The upper end 30 of the outer sleeve 14 is internally threaded to receive a retaining ring 32. The ring 32 bears downwardly against the packing sleeve 24 for assuring an eillcient seal between the inner mandrel 12 and outer sleeve 14, as will be hereinafter set forth. A suitable jamb nut 34 is threadedly secured to the upper end 30 of the sleeve 14 for urging the retaining ring 32 downwardly into a tight engagement with the packing sleeve 24.

The mandrel 12 extends longitudinally through the j.:n1b nut 34 and is slidable therein. A suitable set screw 36, or the like, extends transversely through the sidewall of the jamb nut 34 and into disposition within a longitudinal groove 3S provided on the outer periphery of the inner mandrel 12. In this manner, the mandrel 12 may move longitudinally with respect to the nut 34. However, any rotational movement of the mandrel 12 is transmitted to the jamb nut 34 through the connection between the female spline 38 and the set screw 36. The upper end of the groove 38 is closed at 3% in order to preclude any accidental disengagement of the groove and the screw 36.

The inner mandrel 12 is provided With a plurality of spaced apertures 40 for a purpose as will be hereinafter set forth. An outwardly extending circumferential flange 42 is provided on the outer periphery of the mandrel 12 and spaced below the apertures 40. The flange 42 is adapted to contact the lower shoulder 44 of the flange 28 in order to limit the upward movement of the inner mandrel 12 with respect to the outer sleeve 14. A suitable packing sleeve member 46 is provided around the mandrel 12 below the flange 42 to preclude leakageof uid between the mandrel 12 and the sleeve 14. The mandrel 12 is provided with an externally threaded portion 48 at the lower end thereof for receiving a packing retainer ring 59. The retainer ring '50 is preferably threadedly secured on the mandrel 12 for urging the packing member 46 upwardly against the flange 42, thereby assuring an eicient seal between the mandrel 12 and the sleeve 14.

The outer sleeve 14 is threaded at the lower end 52 thereof to receive a lower sleeve member 54.. A lower mandrel member 56 is threadedly secured to the lower end 48 of the mandrel 12 and extends longitudinally through the lower sleeve 54. An outwardly extending circumferential llange 58 similar to the flange 42 is provided on the outer periphery of the lower mandrel 56 for contacting an inwardly directed circumferential flange 60 provided on the inner periphery of the lower sleeve 54. In this manner, the downward movement of the mandrel 12 and mandrel 56 connected thereto is limited with respect to the outer sleeve 14 and lower sleeve 54. The lower mandrel 56 is provided with a plurality of spaced apertures 62 and disposed below the llange 53, for a purpose as will be hereinafter set forth. A transverse partition member 64 is suitably secured to the inner periphery of the lower mandrel S6 by welding, or the like, and is spaced below the apertures 62. A plurality of spaced apertures 66 are provided in the lower mandrel 56 below the partition 64 for a'purpose as will be hereinafter set forth.

A lower stationary packer sleeve 68 is provided in the lower sleeve 54 around the lower mandrel 56 and is positioned below the flange 6i). The lowermost end 70 of the lower sleeve 54 is internally threaded to receive a retainer ring 72. The ring 72 is preferably disposed adjacent the packing sleeve 68 for urging the packing sleeve upwardly against the flange 60. It will be apparent that the longitudinal compression of the packing sleeve 63 between the ring 72 and flange 60 will cause a radial expansion of the packing sleeve for assuring an eillcient sealing between the lower sleeve 54 and lower mandrel A suitable coupling member or jamb nut 74 is threadedly secured in the lower end 70 of the sleeve 54 and into abutment with the retainer ring 72 for securely retaining the ring 72 in a tight engagement with the packing sleeve 68.

The jamb nut 74 is threaded at its lower end 76 for receiving any suitable well tubing packer joint 78, such as is normally utilized for anchoring the well tubing securely within the well casing. There are many types of these packer joints in use in the industry, and any suitable packer joint may be utilized. A frangible disc member St) is threadedly secured within the packer joint 78 in the proximity of the lower' end 76 of the jamb nut 74. A rod member 82 is welded, or the like, to the transverse partition plate 64 and extends longitudinally downward therefrom through the open lower end 84 of the lower mandrel 56. A suitable centering spider member 86 is secured adjacent the open end 34 in any well known manner for maintaining the rod 82 concentrically positioned within the lower mandrel 56. A downward movement of the rod 82 with respect to the jamb nut 74, as will be hereinafter set forth, will force the rod 82 through the frangible disc for a fracturing thereof, thus opening the interior of the lower mandrel 56 and mandrel 12 to the ilow of the well fluid.

Operation When it is desired to produce oil or oil and gas products from more than one producing horizon or oil bearing formation (not shown) in one Well bore, a packer joint 14 is interposed in the well tubing in such a manner that the joint 1t? will be disposed within the well casing in the proximity of the oil bearing formations. It will be apparent that the over-all length of the tool 10 may vary according to the vertical spacing of the oil bearing horizons.

A plurality of spaced apertures 88 are provided in the outer sleeve 114 spaced below the flange 28 whereby the apertures 88 will be in communication with the uppermost of the two oil bearing formations. The well tubing packer member 78 is expanded or set in any suitable manner (not shown) as is well known for securely anchoring the tubing string and the tool joint 10 within the well casing. The packer member 78 is preferably vertically disposed within the casing between the upper and lower oil bearing formations in order to provide a seal between the two iluid producing zones. In this manner, the fluid of the upper oil zone will be maintained separate and independent from the lower oil zone. The lower end of the well tubing (not shown) is normally open for receiving the tluid of the lower oil zone therein, as will be hereinafter set forth.

After the packer 78 has been set for securing the tubing and dual packing joint 10 within the well casing, the weight at the surface of the well bore may be slacked off whereby the well tubing will tend to move downwardly in the well casing. The outer sleeve 14 and lower sleeve 54 are precluded from any downward movement by their direct connection with the anchoring packing member 78. Thus, the inner mandrel 12 and lower mandrel 56 will be moved downwardly through the outer sleeve 14 and lower sleeve 54 by the weight of the tubing string thereabove. The downward movement of the inner and lower mandrels causes the rod 82 to move downwardly through the frangible disc 8G whereby the disc will be fractured. In this manner, communication is established between the interior of the lower mandrel 56 and the open lower end of the well tubing, as hereinbefore set forth. The well tluid from the lower oil zone may thus low into the lower aca/geste mandrel 56. It will be apparent that the llow of the well uid may be induced in any suitable manner, such as pumping or the like, in instances wherein the well pressure is not suflicient for a natural ow of the oil.

The partition plate 64 limits the upward travel of the well fluid from the lower oil zone through the lower mandrel 56. Thus, the well uid will flow outwardly through the apertures 66. it will be apparent, however, that the apertures 66 are disposed adjacent the lower stationary packing sleeve 68 when the mandrel 56 is in its lowermost position, as shown in FIG. 2, thus the uid from the lower oil zone cannot low out of the mandrel 56, and is contained therein as long as the mandrel 56 is maintained in the lowermost position. As hereinbefore set forth, the downward movement of the mandrel 56 is limited by the contact between the

flanges

58 and 60, thereby assuring that the apertures 66 will be disposed adjacent the packing sleeve 68 in the lowermost position therefor. As shown in FIG. 2, the apertures 40 of the inner mandrel 12 are positioned in the proximity of the apertures 88 provided in the outer sleeve 14 when the mandrel 12 is in its lowermost position therein. e well uid present in the upper oil zone is then free to ow into the sleeve 14 and into the interior of the inner mandrel 12. The slidable packing member 46 precludes any downward ow of the well fluid around the mandrel 12, and the upper stationary packing sleeve 24 precludes any upward flow of the fluid around the mandrel 12. Thus, the uid in the upper oil zone will be directed into the interior of the inner mandrel 12. The partition 64 closes the lower portion of the inner mandrel 12, and since the lower apertures 62 are positioned adjacent the lower stationary packing sleeve 68, the Huid from the upper oil zone will accumulate within the mandrel 12 above the partition 64. As hereinbefore set forth, the well Huid may be produced in any suitable manner, such as by a natural ow or by pumping the Huid to the surface of the well bore.

As the well lluid from the upper oil zone moves upwardly within the mandrel 12, it will move through the tubular member 18, and into the well tubing string connected thereabove (not shown). Thus, the well fluid from the upper oil zone may be produced through the well tubing, thereby precluding contact of the well iluid with the inner periphery of the well casing, and eliminating the possibility of any paraliin accumulating thereon. The fluid from the upper oil zone may be produced through the well tubing in this manner as long as desired by maintaining the

mandrels

12 and 56 in their lowermost position with respect to the outer sleeve 14 and lower sleeve 54. The fluid from the lower zone will be positively sealed off and cannot in any manner be mixed with the fluid from the upper zone.

When it is desired to stop the flow of fluid from the upper zone and begin producing the fluid from the lower oil zone, the weight on the well tubing may be picked up at the surface of the well in any well known manner (not shown) whereby the inner mandrel l2 and lower mandrel 56 secured thereto will be raised vertically within the outer sleeve 1d and lower sleeve 54. As hereinbefore set forth, the upward movement of the mandrel 12 is limited by the contact between the flanges 28 and 4-2. With the

mandrels

12 and 56 in their uppermost position, as shown in FIG. l, the apertures 4t) of the mandrel 12 are disposed adjacent the upper stationary packing sleeve 24. Simultaneously, the slidable packer sleeve 46 is moved into a position adjacent the apertures 88 of the outer sleeve 14, thus shutting off communication between the upper oil zone and the interior of the mandrel i2. However, the apertures 62 and 66 of the lower mandrel 56 are moved upwardly and out of contact with the lower stationary packing sleeve 68. Thus, the well fluid of the lower oil zone which is contained within the lower mandrel S6 below the partition 64 may ow outwardly through the apertures 66 and into the annular space 9-9 between the sleeve 54 and mandrel 56, as shown in FIG. 1. The lower packing sleeve 68 precludes any downward flow of the uid from the annular space 90, and the slidable packing sleeve 46 precludes any upwardly ow of the fluid around the mandrels S6 and 12. The uid from the lower oil zone will thus flow into the interior of the mandrel 56 above the partition 64 through the apertures 62 for communication with the interior of the mandrel 12, whereby it will ow upwardly for production through the well tubing as hereinbefore set forth.

It will be apparent that the fluid from the lower oil zone may be produced through the well tubing as long as desired by maintaining the

mandrels

12 and 56 in their uppermost position with respect to the outer sleeve 14 and lower sleeve 54. The uid from the upper oil zone is positively sealed off from the interior of the mandrel 12, and can in no manner be intermingled accidentally with the fluid owing from the lower oil zone.

By way of summary, the present invention provides a simple and eliicient dual completion packing tool which may be easily installed within a producing well in order to produce well fluid from a plurality of vertically spaced subsurface oil bearing formations. The tool may be readily positioned for production from only one of the oil producing horizons by telescopically positioning the inner mandrel within the outer sleeve. An upper position for the inner mandrel provides communication between the upper oil zone and the interior of the well tubing while simultaneously sealing off the uid from the lower oil zone. Conversely, a lowered position of the mandrel provides communication between the lower oil zone and the interior of the well tubing while simultaneously sealing olf the ow of the tluid from the upper oil zone.

From the foregoing, it will be apparent that the present invention provides a novel dual completion packer joint which may be easily interposed Within the well tubing of a producing oil well for permitting a separate fluid production from multiple subsurface oil bearing horizons. The novel tool may be utilized at substantially any depth within the well bore in accordance with the disposition of the oil bearing horizons. The positive action of the novel tool provides Ifor a simplicity of operation with an eicient control of the flow of the fluid from the subsurface formations. The novel tool is simple and efficient in operation and economical and durable in construction.

Changes may be made in the combination and arrangement of parts as heretofore set forth in the specification and shown in the drawings, it being understood that any modication in the precise embodiment of the invention may be made within the scope of the following claims without departing from the spirit of the invention.

I claim:

l. A dual completion packer joint for an oil well having upper and lower oil bearing formations, and comprising an outer sleeve member adapted to be anchored within the well bore, an inner mandrel telescopically disposed Within the outer sleeve, means providing communication between the upper oil bearing formation and the interior of the mandrel, means providing communication between the lower oil bearing formation and the interior of the mandrel, an imperforate member disposed within the mandrel for precluding -a mixing of the fluids from the upper and lower formations, said inner mandrel in one position having communication with the upper oil bearing formation, a packing member carried `by the outer sleeve for precluding `communication of the lower oil bearing formation with the interior of the mandrel in the rst mentioned position for said inner mandrel, said inne-r mandrel in a second position having communication with the lower oil bearing formation, passageway means provided for bypassing the imperforate member in the said second position of the inner mandrel, and a second packing member carried by the outer sleeve and cooperating with the inner mandrel for precluding communication of the upper oil bearing formation and the interior of the mandrel in the second position for said inner mandrel, and a third packing member carried by the mandrel and cooperating with said mandrel and the outersleeve for precluding the comrningling of the upper and lower formation fluids.

2. A dual completion packer unit for an oil well having upper and lower fluid bearing formations, and comprising an outer sleeve member, an inner mandrel telescopically disposed within the sleeve member, means for limiting the telescopic movement of the mandrel member with respect to the sleeve member, said mandrel provided with open upper and lower ends, a packing sleeve provided in the upper portion of the outer sleeve mem-ber between the inner mandrel and outer sleeve member and stationary with respect to the outer sleeve member, a slidable second packing sleeve member provided between the mandrel and outer sleeve member and slidable with respect to the outer sleeve member, a plurality of apertures provided in the outer sleeve member below the upper packing sleeve and adjacent to the upper formation, a plurality of upper apertures provided in the inner mandrel, said mandrel in a first position relative to said outer sleeve providing communication between said apertures and the open upper end of the mandrel, a member disposed within the mandrel for precluding communication between the open lower end and the open upper end of the mandrel in the said -rst position of the mandrel, said mandrel in a second position relative to said outer sleeve member providing communication between the open lower end and open upper end thereof for permitting production from the lower formation, passageway means provided for bypassing the member within the mandrel when the mandrel is in the said second position, and the aforementioned packing sleeves precluding communication between the apertures in the outer sleeve and the open upper end of the mandrel in said second position for said mandrel, and the second packing sleeve cooperating with the outer sleeve and the inner mandrel for precluding commingling of the upper and lower formation uids.

3. A dual completion packer tool for an oil well having upper and lower fluid bearing formations, and comprising an outer sleeve, an inner mandrel telescopically disposed within 'the sleeve, said inner mandrel provided with a plurality of spaced upper and lower apertures, said sleeve provided with a plurality of circumferentially spaced apertures adjacent to the upper formation, lug means cooperating between the mandrel and sleeve for limiting the telescopic movement of the mandrel within the sleeve, a lower stationary packing sleeve provided between the mandrel and sleeve and stationary with respect to the sleeve for sealing the lower apertures of the mandrel in a lowered position thereof within the sleeve, said upper apertures of said mandrel positioned in communication with the apertures of the sleeve in the lowered position for the mandrel for production from the upper formation, means preoluding communication between the open lower end and the open upper end of the mandrel in the lowered position of the mandrel, passageway means for by-passing said last mention-ed means in the raised position of the mandrel, packing means provided between the mandrel and sleeve and Vstationary with respect to the sleeve for sealing the upper apertures and sleeve apertures in a raised position for the mandrel within the sleeve, said lower apertures open for receiving fluid from the lower formation in the raised position for the mandrel.

4. A dual completion packer tool for an oil well bore containing upper and lower iiuid bearing formations, and

comprising an outer sleeve member adapted to be anchored within the well bore, an inner mandrel telescopically disposed within the outer sleeve member, said outer sleeve member provided with a plurality of spaced apertures in communication with the -well uid of the upper formation, said inner mandrel provided with a plurality of spaced upper and lower apertures, cooperatingy fiange members for limiting the upward and downward movement of the inner mandrel, a packing sleeve member carried by the outer sleeve for sealing the lower apertures from the well fluid during a lowered position of the inner mandrel within the outer sleeve, said upper apertures disposed in communication with the apertures of the outer sleeve in a lowered position for the inner mandrel whereby the well fluid of the upper formation is directed into the inner mandrel, an imperforate member disposed within the mandrel and precluding the downward ow of the well lluid in the inner mandrel, a second packing sleeve member carried by the outer sleeve for sealing the upper apertures and the outer sleeve apertures in a raised position of the inner mandrel, said lower apertures opened to receive Well iiuid from the lower formation in said raised position of the inner mandrel whereby the well Huid is directed into the inner mandrel above said imperforate member, and a-third packing sleeve slidably carried within the outer sleeve by the mandrel and cooperating therebetween to preclude commingling of the upper and lower formation fluids.

5. A dual completion packer tool for an oil well bore containing upper and lower uid bearing formations, and comprising an outer sleeve member adapted to be anchored within the well bore, an inner mandrel telescopically disposed within the outer sleeve member, said outer sleeve member provided with a plurality of spaced apertures in communication with the well uid of the upper formation, said inner mandrel provided with a plurality of spaced upper and lower apertures, means cooperating between the outer sleeve and inner mandrel for |limiting the upward and downward movement of the inner mandrel, a packing sleeve member carried by the outer sleeve for sealing the lower apertures from the well fiuid during a lowered position of the inner mandrel within the outer sleeve, said upper apertures disposed in cornmunica'tion with ythe apertures of the outer sleeve in a lowered position for the inner mandrel whereby the well uid of the upper formation is directed into the inner mandrel, an imperforate member secured within the mandrel for preoluding the downward flow of the well fluid in the inner mandrel, a second packing sleeve member carried by the outer sleeve for sealing the upper apertures and the outer sleeve apertures in a raised position of the inner mandrel, said lower apertures opened to receive well fluid from the lower formation in a raised position of the inner mandrel whereby the well fluid is directed into the inner mandrel and the imperforate member is bypassed, and a third packing sleeve carried by the inner mandrel and cooperating with the outer sleeve to preclude commingling of the upper and lower formation uids.

References Cited in the iile of this patent UNITED STATES PATENTS 1,901,813 Johnston Mar. 14, 1933 2,327,610 Savitz Aug. 24, 1943 2,403,987 Lewis July 16, 1946 2,690,807 Moosman Oct. 5, 1954 2,720,926 Brown Oct. 18, 1955 2,951,536 Garrett Sept. 6, 1960