US2534528A

US2534528A - Combined anchor and packer for use in wells

Info

Publication number: US2534528A
Application number: US707435A
Authority: US
Inventors: John S Page
Original assignee: PAGE OIL TOOLS Inc
Current assignee: PAGE OIL TOOLS Inc
Priority date: 1946-11-02
Filing date: 1946-11-02
Publication date: 1950-12-19
Anticipated expiration: 1967-12-19

Description

J. S. PAGE COMBINED ANCHOR AND PACKER FOR USE IN WELLS Dec. ,19, 195o 2 Sheets-Sheet 1 Filed Nov. 2, 1946 Dec. 19, 1950 J. s. PAGE 2,534,528

COMBINED ANCHOR AND PAOKER FOR USE 1N WELLS Filed Nov. 2, 1946 2 Sheets-Sheet 2 'llllllllfllll/Il/ I4 4 'Illlllllllllllllllllllllll111111111111111 /N VENT By gagnes: page! www Patented Dec. 19, 1950 UNITED STATES PATENT OFFICE COMBINED ANCHOR AND PACKER FOR USE IN WELLS Application November 2, 1946, Serial No. 707,435

(Cl. 16S-12) 6 Claims.

This invention is concerned with a combined anchor and packer for use in wells and it is useful, generally, in wells where it is desired to anchor a part such as a tubing to provide packing at the point of anchorage, it being a general ob- J'ect of the invention to provide a simple, dependable, improved unit of this general character.

The structure that I have provided is useful in wells under various conditions or t perform various operations. However, it is particularly useful in repressuring wells, that is, when high pressure gas is introduced into a marginal well to induce production of one or more central or adjacent wells, and I will therefore describe a form of the invention designed for this type of use, it being understood that I contemplate modification and variation of the design to suit other uses to which the invention can be put.

The structure that I have provided is designed to be coupled onto or in a string of tubing to be run in a casing or well liner and it is provided with a lateral passage for free Comunication between the tubing and casing while being run into the well and is operable when located at the desired point in the well to close such passage and to set slips which anchor the tubing in the casing in a most secure and dependable manner, subject to being released, if necessary, by either upward pull on the tubing or by downward pressure of fluid applied between the tubing and casing.

Tools or structures of the general class to which this invention relates are commonly used at great depths and in practice are generally subject to high pressures or great strains, with the result that it is not uncommon for shifting or working to occur between parts as conditions vary, with the result that when ordinary constructions are employed the anchoring means may be released when such action is not intended. y

A general object of this invention is to provide a structure of the general character above outlined which involves a slip mechanism for anchoring a tubing or the like which mechanism is releasable either by pulling up on the tubing or by the application of fluid pressure downward between the tubing and the casing in which the tubing is located.

It is a further object of this invention to provide a structure of the general character referred to wherein there is a simple practical slip mechanism which is full oating relative to the string of tubing, that is, which is bodily rotatable as well as longitudinally shiftable relative to the tubing so that its action is not dependent upon accurate positioning of the tubing and so that limited working or movement of the tubing may occur without effecting its release,y

A further object o f the invention is to provide a structure of the general character referred to involving a packer which is free to rotate relative to the tubing which it seals and which is operatively connected with the slip mechanism to operate the slip mechanism when forced down by pressure applied from the top of the well by the casing and tubing. I

Another object of this invention is to provide a structure of the general character referred to involving several packers individually rotatable at least one of which is coupled to the slip mechanism to serve as a means whereby such mechanisrn can be operated.

The various objects and features of my invention will be fully understood from the following detailed description of a typical preferred form and application of the invention, throughout which description reference is made to the accompanying drawings, in which:

Fig. l is a longitudinal sectional view of a typical cased well showing a tubing within a liner and showing the structure that I have provided within the liner positioned to be moved therethrough. Fig. 2 is an enlarged sectional view of a portion of the structure shown in Fig. l, showing the upper portion of the tool that I have provided positioned to be moved through the liner. Fig. 3 is a view similar to Fig. 2 showing the lower portion 0f the tool. Fig. 4 is a view similar to Fig. 2 showing the structure that I have provided set or in operating position anchoring the tubing in the liner. Fig. 5 is an enlarged transverse sectional View taken as indicated by line 5 5 on Fig. 4. Fig. 6 is an enlarged transverse sectional view taken as indicated by line 6 5 on Pig. 4. Fig. 7 is a view taken as indicated by line 'l-l on Fig. 6. Fig. 8 is an enlarged plan View taken as indicated by line 8 8 on Fig. 4. Fig, 9 is an enlarged side elevation of the slip mechanism included in the structure showing it expanded and Fig. l0 is an enlarged transverse sectional view taken as indicated by line lll-I0 on Fig. 2.

In the drawings I have shown the structure that I have provided under typical conditions or in a typical situation and have there illustrated a well bore lined with a casing A within which there is a liner B. A string or tubing T is shown extending into or through the liner B and the structure which I have provided is carried on or included in a string of tubing. The tool is so related to the tubing and liner as to be operable to establish a seal between these parts by packing between them and it is operable to anchor the tubing in the liner. In the case illustrated the structure that I have provided is incorporated in the string of tubing T vrather than being applied to the lower end thereof as it may be in some cases.

The tool of the present invention involves, generally a central tubular body C, a slip mechanism or grip device D supported on the body and engageable with the liner B, a mechanical operating means E for the slip mechanism, control means F for the means E, by-pass means G maintaining free communication between the inside of the structure and the outside thereof when the slip mechanism is held inactive or retracted and packing means H operable to pack between or to establish a seal between the tubing and liner and coupled with the slip mechanism through the means E to operate it.

The body C of my construction includes a central tubular part which I will term a core I which part is joined to the upper section of tubing T to depend therefrom. In practice I may couple the core IG to the tubing in any suitable manner, for instance, in the drawings I have shown the core coupled to the tubing 'I by a coupling lila so that the core forms, in effect, a continuation of the tubing. The core I continues downwardly through the mechanism D and serves as a mounting or carrier for the mechanism D.

The slip mechanism D includes, generally, a wedge member II slidable on the core Il), a plurality of slips I2 cooperating with the wedge member and mounting means for the slips including a bracket sleeve I3 mounted on the core I0 and carrying sets of spaced lugs I4, arms I5 projecting upwardly from the slips, ears I6 on the upper ends of the arms cooperating with the lugs I4, a follower ring Il carried on the core confining the ears to the lugs and a compression spring IS normally yieldingly urging the follower downwardly.

The wedge member II is in the nature of a collar with a central longitudinal bore receiving the core Ii! so the wedge member is slidable longitudinally on the core. The wedge member has its outer surface IIa tapered so that the wedge member is considerably smaller at one end than at the other and it is arranged with its small end up so the surface or exterior Ila extends downwardly and outwardly. The slips I2 cooperate with the wedge member I I and they are mounted to depend downwardly to t around the wedge member when in operation. In the case illustrated there are three slips I2 symmetrically arranged around the central longitudinal axis of the structure and each has an outer gripping face provided with wickers or teeth I2a and has an inclined or pitched inner face lh to engage and cooperate with the exterior lia of the wedge member. The exterior of the wedge member and the faces I2b of the slips are related so that when they are engaged as shown in Fig. 4 of the drawings the toothed outer faces of the slips are parallel with the longitudinal axis of the structure and are in gripping engagement with the interior of the liner B.

The bracket sleeve I3 is mounted on the core Ill at a point spacedA above the portion of the core that carries the wedge member. The sleeve I3 is slidably mounted on the core I and when it is in its down position it rests on or stops against the upper end of an enlargement I3a of the core Iii. The sleeve I3 is provided with three sets or pairs of lugs IB, there being a pair of lugs for each slip and the pairs of lugs being spaced around the axis of the structure, as shown in Fig. 6 of the drawings. The lugs I4 are spaced apart forming vertical channels or guideways Ida passing the upper end portions of the slip arms I5.

The slip arms I5 are preferably formed integral with the slips I2 and project upwardly therefrom to extend between the lugs I4. The ears it project from the sides of the arms I5 at the upper ends thereof and are downwardly tapered to suitably t or operate in V-shaped notches la provided in the upper edges of the lugs Ill. The t of the ears in the notches of the lugs is such as to allow the ears to not only move vertically relative to the lugs but to also rock or tilt somewhat relative thereto, as the slips move between an in position such as is shown in Fig. 2 and an out position such as is shown in Fig. 4. It is to be observed that the ears fit the lugs so that the slips are held or coupled to the body through the sleeve which is on the body and yet they are free to shift bodily in order to most advantageously conform to the interior of the liner, an action which is difficult if not impossible to obtain when a common pivotal connection is provided to support the slips.

rThe follower I'I is a ring-like member slidably mounted on the core ID above the ring I3 to rest upon or bear downwardly upon a, bearing point Illa at the upper ends of the arms I5 and their ears I6. The follower I'I with the spring I8 serves as a means retaining the ears in the notches of the lugs. The spring I8 is a helical compression spring surrounding the upper end portion of the core IIB and acting between the coupler Ia and the follower I'I. In the preferred form of the invention a stop sleeve I9 surrounds the core Ill between the coupler Ita and the follower I'I to limit upward movement of the follower on the core and a shoulder ring I9a is interposed between the upper end of the spring and the lower end of the coupler Illa. The relationship of parts is such as to allow for a certain limited longitudinal movement of the follower I'I on the core IU.

The specific slip mechanism that I have just described is more fully set forth and is claimed in my copending application entitled Slip Mechanism for Well Tools, filed November 2, i946, Serial No. 797,436.

The operating means E for the slip mechanism involves an elongate tubular body 2li forming a continuation of core IG, a sleeve 2i slidably supported on the body 2t and a plurality of longitudinally disposed spring fingers Z2 carried by the sleeve. The body 2t is arranged immediately below the core I, in fact, it is preferably joined directly thereto by a threaded connection Zta or the like, so that it forms a continuation of the core and becomes, in effect, a part of the body C of the structure.

The sleeve 2i of means E surrounds body 20 to rotate thereon and to move longitudinally thereon, and it serves primarily as a mounting or carrier for the spring fingers 22. The spring ngers or grips 22 are peferably of the type com- Inonly found in tail pieces or the like employed in well tools and are shaped and carried by the sleeve 2| to normally frictionally engage the interior of liner B. In the case illustrated the lower end portions of the fingers 22 are made fast or secured to the lower end portion of sleeve 2| by suitable fastening devices 23 while the upper end portions slidably bear on the upper end portion of the sleeve where they extend under guards 29. The middle or outwardly bowed portions of the ngers 22 are free and project or bow outwardly to bear on the liner in the Inanner clearly illustrated in Figs. 1 and 2 or" the drawings.

In accordance with my present invention the sleeve 2| is coupled to the wedge member of means D so that these parts move together longitudinally of the body parts. The preferred coupling of the sleeve and wedge member permits of relative rotation between these parts. In the drawings I have illustrated a coupling in the form of a ring 2 la split diametrically and having a lower end portion 2lb screw threaded into the upper end of sleeve 2| and having an inwardly projecting flange 2|c at its upper end engaged in a channel 2 ld in the wedge member at its lower end. When the sections of the ring are together or assembled the portion 2 |b can be threaded into the sleeve 2| and when so engaged with the sleeve the ring is held assembled around the lower end portion of core l!) and the flange portions 2|c are held engaged with the wedge member, this engagement being such as to allow for free rotation of the wedge member relative to the ring.

The control means F for operating means E may involve a simple inverted L slot construction. In the drawings I have shown a pin 46 projecting from the exterior of body section 2S and entering a slot in sleeve 2|. The slot has a vertically disposed or longitudinal portion :il and a top or lateral portion d2 at the upper end of portion 65|. When the pin d@ is engaged in the lateral portion or notch 42 the sleeve 2| is locked against longitudinal movement relative to body section 2l! but when the pin is in register with portion :il the sleeve is free to move longitudinally far enough to permit the full operation of the wedge member relative to the slips l2.

The bypass means G establishes free communication between the inside and the outside of the tool when the control means F is set holding the wedge member in the down position shown in Figs. l and 2. The means G is formed of suitably ported portions of the body 2&3 and sleeve 2| and it may involve one or more bypass ports 50 in the body section intermediate its ends where it is covered by the sleeve 2|. Separate or individual ports can be provided in sleeve 2| to cooperate with ports e. However, as shown in the drawings, I may ultilize the lower end portien of the slot to cooperate with the port 50 to be in register therewith when the pin is engaged in the lateral portion 42 of the slot. In practice it may be desirable to provide more than one port 5d or more ports 553 than there are slots, in which case longitudinal ports 5de may be provided in the sleeve 2S at suitably located points around the sleeve to properly cooperate with the ports iis so that all the ports 5) are open when the pin d@ is in the lateral portion of the slot, but are closed when the pin is in or in register with the longitudinal portion 4| of the slot. In practice I preferably provide packing means or sealing rings E5 between the body and sleeve above and below the ports 50.

The packing means H that I have provided is located below the structure thus far described.

In other words, it is located immediately below the means E or on the lower end portion of the tool. In its preferred form the packing means involves an elongate tubular body section 60 and one or more packing units 6| carried on the body. The body 6|) may be a simple tubular part having its upper end joined to the lower end of body 20 to form a continuation thereof and to thereby become, in effect, a part of the body C of the tool. I have shown the upper end of the body section is threaded into the lower end of the body section 2D at 62.

The body section 6% is suciently long to properly accommodate the desired number of packing units 6| and it will be apparent that it can be made of any length to accommodate any desired number of packing units. The lower end of the body 66 may be provided with any suitable form of end part to finish the tool in any desired manner, or, as shown in the drawings, it may be coupled to the upper end of the lower section of tubing B. In the drawings I have shown a threaded connection 63 between the lower end of body 5d and the upper end of the lower` tubing section. Where the tubing is joined to the lower end of body section @El the upper end of the tub- .ing section forms or becomes a stop or retainer for the packing units 6| and to that extent is a part of the present tool.

In the drawings I have illustrated the structure as involving three packers, the uppermost o1" which is faced upwardly to pack against downward pressure while the lower two are faced downwardly to pack against upward pressure. It will be understood that any desired number and arrangement of packers can be employed as circumstances require.

Each packer tl is, in general, an independent or individual unit freely movable cn the body section 553. In the preferred form of the invention each packer unit involves an elongate tu bular sleeve Ee having a bore or opening 'H slidably passing body section (it. The sleeve is provided at one end with an enlargement or head l2 which carries packing 'i3 and forms an abutment or shoulder M for a packing support l5. The head is shown formed separate from the rest of the sleeve and is secured thereto by welding lt. The packing 'I3 is a suitable packing or sealing ring carried in a channel provided on the sleeve lll).

The packing support 'l5 may be a simple collar slid onto the sleeve from the end opposite head 'i2 until it bears against shoulder Eil and it has a projecting flange which forms a retainer for the annular body o1 the packing element. The packing element 'i3 is preferably a unit oi rubber or the like having an annular body portion iid carried on the sleeve iti in engagement with support 'F5 so that it extends under the flange of the support. An annular extension or lip part di projects from the body Sii to bear outwardly against the inner wall ci liner B. Through this construction there is a chamber or cavity 62 within or behind the lip portion for the reception of fluid so that iluid pressure acts to hold the lip portion out against the liner. A retainer or collar S3 is applied to the sleeve 'i9 to retain the packer in engagement with the support i5. The retainer is shown threaded en the end of the sleeve and a spacer Sd is arranged between the collar and the body 6d defining the channel in which the packing is carried. The spacer 84 is long enough so that the collar 83 is outward of or beyond the free end of lip 8l where it is easily accessible.

In accordance with my present invention I couple one or more of the packing units with the wedge member of the means D and in the preferred arrangement I employ packer units that are independent of each other, and I couple only the uppermost packer unit to the wedge member l l of means D through the sleeve 2i of means E, the sleeve 2! being coupled to the wedge member ll through the construction hereinabove described. In the particular case illustrated I couple the uppermost packer unit iii with the lower end or" sleeve 2l by a diametrically split coupler 98 which has a threaded upper end portion til that threads into the lower end of sleeve 2 l and which has an inwardly turned flange 92 that extends into an annular channel 93 in the upper end portion of the part or collar S3 of the uppermost unit Si. Through the split coupler 9B which is held assembled when it is threaded into the lower end of sleeve 2 l, the upper packer unit El is coupled to the sleeve to move longttudinally therewith and yet these parts are free to rotate independently of each other.

A typical use or application of the structure that I have provided involves attachment of the structure to or in a string of tubing T as shown in the drawings. With the means F latched holding the slip mechanism released, that is, holding the wedge member Il down relative to the slip, the tool is run into the well or into the liner B. The spring fingers 22 frictienally engage the interior of the liner and slide along inside the liner as the tool is lowered therein. As the tool is lowered free circulation is maintained between the inside of the tool and the outside thereof through the ports 50.

When it is desired to set the tool, as for instance, to operate it so that the ports S are closed and the slip mechanism set, the tubing 'I' is rotated to turn the body 2li of the means E to disengage pin All) from the notch 42 of the slot. The tubing T is then lowered so that pin i9 moves down in the portion 4l of the slot, sleeve 2l being held against movement by the engagement of the spring lingers 22 with the interior of the liner B. As this operation occurs the slips l2 are moved down over the wedge member li which is held against movement with the liner, and the ports 5] of the means G are covered and closed by sleeve 2 l. The said movement or operation will continue until the slips l2 are wedged tightly out in the liner B by the wedge member ii, whereupon the slip means D is fully set and forms an anchor on which the tubing T rests.

It is to be understood, of course, that the packing units El being in engagement with the interior of liner B paola the tool in the liner so that the only now possible through the tool is through the body sections thereof. If the tooi is being used in a repressuring operation gas or suitable uid is circulated down through the tubing T and through the structure that I have provided to enter the well below the packers and any upward pressure occurring on the tool acts on the packers tending to force them up and thereby causes the wedge member i l to be tightly engaged in the slips l2. The relative rotation that I have provided between the various essential parts allows for free turning and manipulation and the freedom of movement that I have provided for the slips as well as the wedge member of the slip mechanism assures proper maintenance of the slip mechanism in the engaged position during all normal operation of the device.

When it is desired to Withdraw the device er the tubing from the liner it is ordinarily merely necessary to pull up on the tubing which operation causes the slips I2 to be lifted up or away from the wedge member H so that they are freed thereof and allowed to collapse from the expanded position to a collapsed position such as is shown in Fig. 2. If for any reason it is not desired to pull up on the tubing to release the slip mechanism or if this cannot be done easily I may release the mechanism by introducing pressure from the top of the Well between the liner B and the tubing T so that it acts on the uppermost packer unit BI, forcing it down so that the sleeve 2l is moved down with corresponding downward movement of the wedge member which is coupled to the upper end of the sleeve. When the Wedge member is thus pulled or moved down it is released from the slips allowing them to collapse and free themselves from the liner.

I-Iaving described only a typical preferred form and application of my invention, I do not wish to be limited or restricted to the specific details herein set forth, but Wish to reserve to myself any Variations or modications that may appear to those skilled in the art and fall within the scope of the following claims.

Having described my invention, I claim:

l. In a tool of the character described, an elongate tubular body, a tapered Wedge member shiftable longitudinally on the body, slips mounted on the body to shift bodily relative thereto and engaged by the wedge member and expansible into gripping engagement with a surrounding tubular well part by the wedge member upon longitudinal movement of said wedge member on said body relative to said Slips, a sleeve slidable longitudinally on the body, spring iingers carried by the sleeve frctionally engageable with a surrounding tubular well part, means swivelly coupling the sleeve and wedge member together to move together longitudinally of the body, the sleeve having an inverted L-shaped slot therein, a pin projecting from the body and into the slot controlling movement of the sleeve and wedge member longitudinally of the body, and a packer located below the sleeve and surrounding the tubular body, the packer being freely rotatable on the body and shiftable longitudinally thereof with the sleeve and being engageable with a surrounding tubular well part to establish fluid tight sealing engagement therewith.

2. In a tool of the character described, an elongate tubular body, a tapered wedge member shiftable longitudinally on the body, slips mounted on the body to shift bodily relative thereto and engaged by the Wedge member and expansible into gripping engagement with a surrounding tubular well part by the wedge member upon longitudinal movement of said wedge member on said body relative to said slips, a sleeve slidable longitudinally on the body, spring lingers carried by the sleeve frictionally engageable with a surrounding tubular Well part, means coupling the sleeve and wedge member together to move together longitudinally of the body, the sleeve having an inverted L-shaped slot therein, a, pin projecting from the body and into the slot controlling movement of the sleeve and Wedge member longitudinally of the body, a packer slidable on the tubular body below the sleeve and engageable with a surrounding tubular well part to establish fluid tight sealing engagement therewith, and means coupling the packer and sleeve together to move together longitudinally of the body.

3. In a tool of the character described, an elongate tubular body, a tapered wedge member shiftable longitudinally on the body, slips mounted on the body to shift bodily relative thereto and engaged by the wedge member and expansible into gripping engagement with a surrounding tubular well part by the wedge member upon longitudinal movement of said wedge member on said body relative to said slips, a sleeve slidable longitudinally on the Ibody, a spring nger carried by the sleeve frictionally engageable with a surrounding tubular well part, means swivelly coupling the sleeve and wedge member together for free relative rotation and to move as a unit longitudinally of the body, the sleeve having an inverted L-shaped slot therein, a pin projecting from the body and into the slot controlling movement of the sleeve and Wedge member longitudinally of the body, a packer slidable on the tubular'body below the sleeve and engageable with a surrounding tubular Well part to establish fluid tight sealing engagement therewith, and means coupling the packer and sleeve together to move as a unit longitudinally of the body.

4. In a tool of the character described, an elongate tubular body, a tapered wedge member shiftable longitudinally on the body, slips mounted on the body to shift bodily relative thereto and engaged by the wedge member and expansible into gripping engagement with a surrounding tubular well part by the wedge member upon longitudinal movement of said wedge member on said body relative to said slips, a sleeve slidable longitudinally on the body, spring ngers carried by the sleeve frictionally engageable with a surrounding tubular well part, means coupling the sleeve and wedge member together to move together as a unit longitudinally of the body, the sleeve having an inverted L-shaped slot therein, a pin projecting from the body and into the slot controlling movement of the sleeve and wedge member longitudinally of the body, a. packer slidable on the tubular body below the sleeve and engageable with a surrounding tubular well part to establish fluid tight sealing A'engagement therewith, and means swivelly coupling the packer and sleeve together for free relative rotation and to move together as a unit longitudinally of the body.

5. In a tool of the character described, an elongate tubular body, a tapered wedge member shlftable longitudinally on the body, slips mounted on the body to shift bodily relative thereto and engaged by the wedge member and expansible into gripping engagement with a surrounding tubular well part by the wedge member upon longitudinal movement of said wedge member on said body relative to said slips, a sleeve slidable longitudinally p on the body, a spring finger carried by the sleeve frictionally engageable with a surrounding tubular well part, means swivelly coupling the sleeve and wedge member together to rotate freely relative to each other and to move together as a unit longitudinally of the body, the sleeve having an inverted L-shaped slot therein, a pin projecting from the body and into the slot controlling movement of the sleeve and wedge member longitudinally of the body, a packer slidable on the tubular body below the sleeve and engageable with al surrounding tubular Well part to establish iluid tight sealing engagement therewith, and means swivelly coupling the packer and sleeve together to rotate freely relative to each other and move together as a unit longitudinally of the body.

6. In a tool of the character described, an elongate tubular body, a tapered wedge member rotatable on the body and shlftable longitudinally on the body, slips mounted on the body shiftable bodily around the body and longitudinally relative thereto, the slips being engaged and expanded by the wedge member upon movement of the wedge member longitudinally on the body, a sleeve slidable longitudinally on the body and rotatable thereon, bypass ports in the sleeve and in the body where the body is surrounded by the sleeve, the ports in the body and sleeve being in register and providing communication between the interior and exterior of the body when the sleeve is down holding the Wedge member released from the slips and the port in the body -being closed by the sleeve when the sleeve is up holding the wedge member engaged with the slips, means at the sleeve controlling longitudinal movement of the sleeve on the body operable by rotation of the body relative to the sleeve and normally releasably holding the sleeve in position where it holds the wedge member down relative to the slips, spring lingers carried by the sleeve establishing frictional engagement with a surrounding tubular Well part, means swivelly coupling the sleeve and Wedge member together to rotate freely relative to each other and to shift as a unit longitudinally of the body, the sleeve having an inverted L-shaped slot therein, a, pin projecting from the body and into the slot controlling movement of the sleeve and Wedge member longitudinally of the body, a packer around the body below the sleeve, and means swivelly coupling the packer and sleeve together to rotate freely relative to each other and to shift as a unit longitudinally of the body.

JOI-IN' S. PAGE.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 2,085,997 Phipps July 6, 1937 2,182,196 Brown Dec. 5, 1939 2,187,482 Baker et al. Jan. 16, 1940 2,378,374 Roe June 19, 1945 2,380,612 Quintrell July 31, 1945