US3771343A

US3771343A - Swaging tool

Info

Publication number: US3771343A
Application number: US00237990A
Authority: US
Inventors: J Dawson
Original assignee: McDonnell Douglas Corp
Current assignee: McDonnell Douglas Corp
Priority date: 1972-03-24
Filing date: 1972-03-24
Publication date: 1973-11-13
Anticipated expiration: 1990-11-13

Abstract

A swaging tool for joining the ends of a number of tubes by a coupling member that may be a straight sleeve, an elbow, a tee, a cross, or some other configuration, said tool comprising swaging elements normally loosely mounted when in open position for receiving the members to be joined, and force supplying means acting substantially simultaneously on the die elements to move the die elements relative to each other and to the members to be joined so as to circumferentially enclose and radially inwardly swage the members.

Description

PATENTEBnuv 13 I975 sum 1 [IF 3 SWAGING TOOL This application is a continuation of my prior application Ser. No. 28,578, filed Apr. 15, 1970, now abandoned.

This invention relates to improvements in radial swaging tools, and is more particularly directed to an unique small-sized, but extremely efficient and powerful radial swaging tool.

The present tool has been developed for the purpose of practicing the swage-joining of tubes in a high pressure hydraulic system and the like; one such fitting being disclosed in my application Ser. No. 739,528 filed June 24, 1968 and entitled Coupling Fitting for Connecting Two Parts. In that prior application the fitting was swaged by axial movable dies. In the embodiment shown in this application the swaging tool performs the swaging operation by a plurality of die elements that are interchangeably carried in a pair of movable die blocks which do not have to be directly interconnnected but which cooperate with each other in a unique manner to be set forth in the following specification.

The objects of the invention are to provide a simple lightweight and compact swaging tool, to provide a swaging tool that may be manually held and which will fit into small, generally hard to reach areas where tubing is required to be joined, to provide a simple arrangement in which the tool may be mounted and dismounted without requiring an excessive amount of space or working area, and to provide a tool that may be quickly mounted and dismounted so that the joining of two tubes can be accomplished with the expenditure of a minimum amount of time.

The foregoing objects of the invention are obtained in a swaging tool comprising a pair of die blocks operatively mounting swaging elements which make up a complete complementary circumference surrounding the coupling member to be swaged, and force supplying means acting substantially simultaneously on the die blocks to move the die blocks relatively toward each other and effectively close the swaging elements radially onto the coupling member with the required amount of force to radially contact the coupling member over the end of a tube.

The objects of the invention are also obtained in an improved swaging tool for swaging a sleeve member onto a tube, which tool comprises a body having a working space closed at the bottom and two opposed spaced sides with the working space open at the opposite ends between the sides so as to receive the sleeve member and tube to be swaged, a die block mounted adjacent the bottom wall in the working space, a second die block receivable in the working space adjacent the first die block and in position to engage both the sleeve and tube, means between the side walls and the second mentioned die block to retain the latter die block in the working space, force applying means adjacent the bottom wall engaged with the first mentioned die block to force the die blocks relatively toward each other, and means adjacent one of the open sides of the tool body and generally in alignment with the die blocks so as to be in a position to resist the axial thrust of the elongation of the sleeve member upon circumferential swaging thereof.

DESCRIPTION OF THE- DRAWINGS FIG. 1 is a perspective of the radial compression tool of this invention;

FIG. 2 is a top view of the tool seen in FIG. 1;

FIG. 3 is an exploded perspective veiw of the tool of FIG. 1 showing the components of the tool with the main frame partly broken away;

FIG. 4 is an exploded perspective view of the inner and outer die blocks and the parts and elements operatively carried by the die blocks;

FIG. 5 is a sectional view of the assembled tool as seen along line 55 in FIG. 1;

FIG. 6 is a fragmentary sectional view taken at line 6--6 in FIG. 5;

FIG. 7 is another sectional view taken at line 7-7 in FIG. 5 showing the tube ends mounted in a sleeve with one portion of the sleeve radially swaged upon a tube end;

FIG. 8 is a sectional view of the tool seen at line 88 in FIG. 7 but with an elbow sleeve radially swaged upon a tube end; i

FIG. 9 is a fragmentary sectional view taken at line 99 in FIG. 7, showing the tool in closed position; and

FIG. 10 is a further fragmentary sectional view showing additional details of a modification of radial swaging dies having faces configured for indenting both cylindrical sleeve and tubing end portion.

DESCRIPTION OF THE SWAGING TOOL Reference will be made to FIGS. 1 and 2 for a general understanding of the radial swaging tool construction. The tool comprises a body 12 formed with a bottom wall 13 apertured at 14 to open to a piston chamber 15 supplied with pressure fluid by a conduit or swivel connection 16. The means 16 also exhausts the chamber 15. The body 12 has opposite side walls 17 and a connecting end wall 18 opposite an open end formedwith facing parallel slide grooves 19 formed in the respective side walls 17 adjacent the open end. The end wall 18 is formed with a semi-circular socket 20 having a groove 21 formed therein. The upper margin of each side wall 17 is formed with spaced and inwardly projecting teeth 22 the bottom surfaces 23 of which'are an- I gularly undercut for a purpose to appear.

The body 12 (FIG. 3) receives a lower die block 24 in which are operably assembled a plurality (three in number) of die elements 25. The die block 24 is moved into the body 12 through the open end between slide grooves 19, and a cylindrical boss 26 on its lower surface is adapted to seat in the body aperture 14 when properly installed in the body 12. An upper die block 17 is formed to receive a plurality of die elements 25 (these die elements may be seen in FIGS. 4 and 5), and the opposite margins of the die block have a plurality of'spaced teeth 28 the upper surfaces 29 of which are bevelled to match the bottom surfaces 23 of the body side wall teeth 22. The spacing of the body-side wall teeth 22 is such that the teeth 28 on the margins of the upper die block 17 may pass therebetween upon moving the die block 27 into position on top of the lower die block 24. After insertion of the upper die block 17, it is moved axially until the teeth surfaces 23 and 29 fully mesh.

The components of FIG. 3 include a locking slide 30 for the

die blocks

24 and 27, the slide having side flanges 31 which are received in the slide grooves 19 in the open end of the body 12, and a removable back-up fitting 32 of U-shape having a flange 33 received in the slide groove 21 in the end wall 18. A lock element 34 is secured to end wall 18 by a threaded member 35 engaging in a threaded opening 36. The die block locking slide 30 is provided with a suitable handle 37 located centrally below a tube-receiving upwardly opening cutout 38.

The several components carried by the

respective die blocks

24 and 27 may be seen in FIG. 4 to which reference will now be directed. It will be understood that each die block carries a plurality of die elements 25 which are substantially similar and each of which, in FIG. 4, is formed with a forming face 39 which is an axially elongated segment of a cylinder having opposite outwardly bevelled ends 40 and a projecting lip 41. One longitudinal margin of each die element 25 is formed with a recess 42 to receive a resilient spacer element 43 which operates to maintain the die elements in an open position, substantially evenly spaced, to permit coupling insertion for joining tube ends. In FIG. the die elements are shown in open position, and in FIG. 9 they are closed about a tube and coupling sleeve.

The lower die block 24 (FIG. 4) is formed with three interior elongated faces 44. The die elements 25 are placed against these faces 44, and opposite end keepers 45 of semi-circular form are mounted by radially extending flanges 46 in receiving grooves 47 in the opposite ends of the die block 24. Keeper clips 48 are placed across the back of the die block 24 such that the arms 49 fit into radial end grooves 50 in the die block 24 and extend inwardly. The respective ends 51 of the clip arms 49 snap into receiving sockets 52 in the respective keepers 45 to retain the keepers engaged over the respective axially projecting lips 41 on the die elements 25. The keepers 45 loosely retain the die elements 25 so that there is radial and tangential movement, and initially the resilient elements 43 hold the die elements in spread-out positions against the die block inner faces 44.

The upper die block 27 is similarly formed with keep- 7 ers 45 and retainer clips 48, and the several parts thereof will have similar reference numerals to designate the same as for the lower die block components. The upper die block 27, however, is provided with axial seats 53 and aligned end grooves 54 to receive the clips 48 and clip arms 49 respectively. Since the upper die block is inserted as a separate loose assembly, an auxiliary locating member 55 is required. The auxiliary keeper 55 is formed with spaced axially inwardly directed fingers 56 at opposite sides of a central cut-out 57. The fingers 56 extend inwardly to locate the sleeve fitting (FIGS. 7 and 8) axially and retain it in position.

The keeper 55 is secured by opposite ears 58 and threaded elements 59 against the end of the die block 27 at the at the threaded apertures 60. Ears 58 also act as stops to bear on the end of outer teeth 22, thereby locating die block 17 in side walls 17 and accurately positioning dies 25 mounted in block 27.

The assembly of the tool of FIG. 1 is seen in greater detail in FIGS. 5, 6 and 7 and reference is now made to these views. The cylindrical boss 26 on the underside of the inner die block 24 fits into the body aperture 14 and serves as a piston rod for the die block 24. A snapin retainer plug 61 is received in the bore 62 of the boss 26, and a pair of depending fingers 63 having bulbous end portions 64 snap downwardly into a socket 65 in the central portion of the power piston 66 to hold the die block and piston in operative association. The power piston is initially seated in the socket 67 of a closure cap 68 threadedly received in the open lower end of the cylinder 15. A seal ring 69 is mounted in the axial flange of the cap 68 to engage the inner wall 70 of the cylinder. The power piston 66 has its enlarged skirt 71 slidably received in the cylinder and a seal ring 72 is carried thereby to engage the cylinder wall 70. A piston return spring 73 is mounted in an annular recess 74 in the piston and its inner end abuts the bottom wall of the body 12.

TOOL OPERATION Supply of pressure fluid through conduit 16 drives the piston 66 upwardly (FIG. 5) against the return spring 73 and raises the inner die block 24 by engaging the boss 26. The inner die block 24 moves toward the outer die block 27 which is securely held by the engagement of the teeth 28 with body side wall teeth 22 (FIG. 5). The initial spacing of the inner and

outer die blocks

24 and 27 is chosen such that the respective die elements 25 have the desired operating reaction to close radially upon the coupling sleeve S (FIG. 7) and swage it upon the end portion of the tube T positioned within the sleeve S. The radial swaging of the sleeve S produces some axial elongation of the sleeve and this is accommodated by clearance between the back-up fitting 32 carried in the end wall 18 of the tool body 12 and spring fingers 56. As is seen, the end wall 18 is spaced from the die

blocks

24 and 27 to accommodate the length of the sleeve S that extends outwardly from the die blocks. After the first portion of the sleeve S has been swaged onto the tube T the fluid pressure is exhausted to allow the die blocks to open up (FIG. 5).

The tool body 12 may then be taken off and turned end for end or rotated (FIG. 7) an d l ocated with the d'i' elements 25 over th e left hand portion of sleeve S, whereupon the admission of pressure fluid will actuate the

die blocks

24 and 27, as before, to complete the swaging of the sleeve upon the second tube T.

During the application of pressure fluid on the power MODIFICATIONS The present tool is small and compact so it willeasily fit into restricted spaces, and it may be initially angularly located or turned on sleeve fittings to a position where the pressure fluid conduit 16 will not interfere with adjacent structures such as can be found in aircraft construction. The body is capable of withstanding pressure fluid up to several thousand pounds per square inch. The view of-FIG. 7 is of the present swaging tool as applied to a straight sleeve for connecting two tube end portions in axial alignment.

The tool may also be applied to other types of fittings and one has been shown in FIG. 8 where the tube T is (see FIG. to provide guidance for the elbow E and I prevent its movement from the desired alignment.

In FIG. 10 there is shown amodified configuration for the swaging die elements, and in this view the die elements 25A are formed with a corrugated or suitable configured face 39A which will produce a circumferentially indented sleeve portion on the elbow E, as well as also indenting the tube T. In other respects the tool shown in FIG. 10 is substantially identical with the tool heretofore described.

The tool heretofore described, including its modifications, is intended to radially swage and effect joining of tubes by either straight sleeves, elbows, tees or crosses, to name a few of the various tube joining devices. A wide variety of tubing materials may be assembled with the present tool. Fittings may be formed of steel, aluminum, titanium,'copper or other material and the tubes may be formed of corresponding material or or different materials. For example, a steel sleeve may be used for joining high or medium strength stainless steel tubing or for joining high strength steel tubing, titanium tubing, or aluminum tubing.

It will be understood that the present tool is equipped with six swaging die elements which are loosely contained in inner and outer die blocks, and all are subject to the swaging action upon delivery of a pressure fluid at one point on the inner die block. The present tool may be utilized for a range of fittings merely by interchanging the die elements. In mounting the tool in operative position it is necessary to remove the outer die block 27 and this is done by sliding the die block axially the distance of one tooth 28 so that the respective teeth 28 will pass through the spaces between the teeth 22 of the body walls 17. The tube coupling sleeve, elbow, tee, or cross is inserted in the lower die block and the outer die block is then slid back into position so that the die elements 25 are loosely positioned surrounding the portion of the sleeve or connector that is to be swaged. Pressure fluid is then admitted at the conduit 16 and this results in the displacement of the lower die block 24 (FIG. 5) outwardly toward the outer die block 27. The die elements 25 close about a fitting and apply a radial inwardly directed swaging force simultaneously around the circumference of the fitting. As the fitting is swaged, axial loads are generated which are taken at the back-up element 32 (FIG. 7) and by the resilient fingers 56 of auxiliary keeper 55. The axial and radial loads cause the elements to slide in the inner and outer die blocks. To minimize friction under the tremendous swaging loads imposed, Teflon is applied to one surface of each sliding pair of surfaces. Lubricants, as fluorocarbon spray, baked-on dry film lubricants, or other type may be used. It may be preferable to treat the surfaces 44 in the die blocks 24 and 27, although the back surfaces of the die elements 25 may be coated or treated with suitable lubricant material. The friction minimizing coating is not conveniently shown in the drawing, but it is appreciated that the surface subject to sliding reaction can be treated in the manner set forth.

It is comtemplated that for low strength materials such as copper or aluminum, it is possible to avoid the use of pressure fluid by replacing the member 68 with a screw threaded jack element, cam device, or other force amplification mechanism that will exert the required swaging pressure on the boss 26 at the underside of the inner die block 24. A small, externally mounted hand crank may be used to exert the required swaging pressure. Electrical or pneumatic motor drives may also be employed.

It should be appreciated that the present tool is uniquely designed to obtain great swaging force with an exceedingly small and low weight tool. The present tool is unique in that the fitting is accurately positioned during the swaging to prevent axial squeeze-out of the fitting. The principle of using normally loosely mounted die elements is unique, and all of the die elements are reversible and interchangeable. The die sector interior conical angle of approximately 15 imparts an improved gripping function between the sleeve and the tube being joined. The material flash which is usually formed between the parting line of swaging dies is kept to an acceptable limit, and the ramp angles where the die elements are supported in the die blocks may be optimized for good reaction with proper lubricant treatment so that the swaging force may be easily transmitted, substantially uniformly around the circumference of the fitting being swaged.

Versatility of the tool is unique in that various types of threaded fitting ends may be swaged to many tube types. A significant reduction is expected in tubing rejects due to tube end preparation, as in flaring.

Although six die sections have been employed in the present design, it becomes obvious that a greater or lesser number of dies may be employed with a corresponding change in die block ramp angles.

What is claimed is:

1. A swaging tool for joining the end of a tube in a coupling member by swaging the tube and coupling into connection, said tool comprising a pair of die blocks movable relative to each other between open and closed positions, each of said die blocks operatively supporting at least three swaging die elements in side-by-side position such that an intermediate one of said-die elements is movable between a position floating in said die blocks with said die blocks open and a position solidly engaged in said die blocks with said die blocks closed and the other die elements are slidable relative to and in said die block and movable substantially radially from said die element to a position to embrace said die element upon die block closing movement and force said intermediate die element into said solidly engaged position, and means engaged with both of said die blocks to apply swaging force thereon simul- I taneously, said last means having a substantially rigid body engaged with one die block and a force applying means in said body engaged with the other one of the die blocks and movable in said body.

2. The tool of claim 1 wherein said body is formed with a working space defined between a pair of opposed walls having retaining elements and a third wall joining said pair of walls and formed with a cylinder to receive said piston, said one of said die blocks being normally engaged by said retaining elements and said other one of said die blocks being initially engaged on said third wall and movable therefrom into closed position by said piston.

3. In a tool for circumferentially swaging a sleeve member onto a tube, the improvement which comprises a tool body having a working space therein defined by bottom and opposed spaced side walls, said working space being generally open at opposite sides between said side walls to receive the sleeve member and tube to be swaged, a first die block mounted in said working space adjacent said bottom wall, a second die block receivable in said working space adjacent said first die block and in position to engage upon the sleeve and tube to be swaged, means on said side walls and second die block engaged with each other to retain said die block in the working space, force applying means adjacent said bottom wall engaged with said first die block, and means on said tool body adjacent both of said open sides and located generally in alignment with said die blocks, said last means allowing axial elongation of the sleeve member and resisting the axial thrust of the sleeve and tube with circumferential swaging of the sleeve member.

4. The tool improvement of claim 3 wherein said second die block retaining means includes spaced elements on said opposed side walls and matching spaced elements on said second die block, said spaced elements being movable into engaging registration upon relative axial displacement of said tool body and second die element, the axial movement amounting to substantially the axial dimension of one space between said spaced elements.

5. A swaging tool for radially swaging a sleeve over an internally telescoped part, said tool consisting of a body formed with a piston chamber adjacent one end and said body having an opposite end extending axially outwardly from said piston chamber, a first die block at said opposite end, a second die block received in said opposite end of the body between said first die block and said piston chamber, a piston recipracably operative in said piston chamber, a piston rod movable axially in said body and engaged between said piston and second die block, a source of pressure fluid connected to said piston chamber to supply fluid to displace said piston rod and second die block toward said first die block, swaging die means carried by said die blocks in position to engage the sleeve around its circumference and swage it about the internally telescoped part, said die means responding to the application of pressure fluid on said piston by conforming to the configuration of the sleeve and swaging it onto the internally telescoped part, and means in said piston chamber retracting said piston to permit separation of said second die block from said first die block upon completion of the swaging.

6. The swaging tool set forth in claim 5 wherein said swaging die means have configured faces to radially indent the sleeves into the internally telescoped part, and said die means are removably mounted in said die blocks.

7. The swaging tool set forth in claim 5 wherein said first and second die blocks are relatively slidable into and out of said opposite end of said body, and said body is provided with means adapted to engage said first die block upon sliding the same into said opposite end.

UNITED js AT s PATENT OFFICE 1 I CERTIFICATE OF CORRECTION Patent No. 3,711,343. Dated Nov; .13, 1973 Inventor(s) -A- n I Q 7 v It is certified that error appears in th above-ident ifid patent and that said Letters Patent are hereby corrected as shown below:

In Column 2, at i.r 1e."53, humeral, 1-7 shouic l i l' xgrie" 27', i n: th'sam'e colxIInrI a t l i ne th' numeral I7 have bee 27-, irI the' sia jni c hImI Iat' lin e' 6 3, 17 shou'ld-haxfe v In 3 t li n eirs9 f Izh eixjptneral '17 (first c aceru' r lc i) v s l loiil-d have 27'. f i

S ig n ed' arid s 'a le d t' zhis 214t da of Septembr 1'9 74; j

, (SEAL) Attest: I

McCOY GIBSON 'J'RLQY c. MARSHALL .Attesting Officer I mi s n r 15 f FORM PO-1050 (10-69) v v

Claims

1. A swaging tool for joining the end of a tube in a coupling member by swaging the tube and coupling into connection, said tool comprising a pair of die blocks movable relative to each other between open and closed positions, each of said die blocks operatively supporting at least three swaging die elements in side-by-side position such that an intermediate one of said die elements is movable between a position floating in said die blocks with said die blocks open and a position solidly engaged in said die blocks with said die blocks closed and the other die elements are slidable relative to and in said die block and movable substantially radially from said die element to a position to embrace said die element upon die block closing movement and force said intermediate die element into said solidly engaged position, and means engaged with both of said die blocks to apply swaging force thereon simultaneously, said last means having a substantially rigid body engaged with one die block and a force applying means in said body engaged with the other one of the die blocks and movable in said body.