US2701584A - Thread and tube protector - Google Patents

Description

Fell 8, 1955 R. A. PHILIPS THREAD AND TUBE PROTECTOR Filed May 29. 195o E INVENTOR Rnvfmond Phi lips BY i ATTORNEYS Z THREAD ANDr TUBE PROTECTOR Raymond A. Philips, Cleveland, Ohio, assignor to Protctor Products Inc., Cleveland, Ohio, a corporation o Ohio Application May 29, 1950, Serial No. 164,980v

8 Claims. (Cl. 13S-96) This invention relates to protector caps for covering andv protecting the plain or threaded ends of pipes, tubes, and the like, while performing various operations thereon, and during packing, shipping, and handling of the same.

The'general object ot' the invention is to provide a new and improved thread protector.

A more specific object or' the invention is to .produce a metal thread protector having a soft lining held therein more securely than in prior art devices of this character.

Another specific object of the invention is to provide an 4improved thread protector and liner assembly that may be formed with a single stamping operation of a punch press or the like, whereby the assembly of separately formed metal shells and liners is eliminated.

Characteristic features of the method aspect of the invention are the simultaneous severing of plates or discs of metal and liner material from superposed sheets thereof and movement of severed metal and liner plates or discs together against a mandrel or stake, followed by pressing the twoy plates or discs together over the end of the mandrel, substantially without drawing the metal and 1n such manner as-to fold the metal forming the sides of the resultingmetal shell and to lock compressed portions of the liner between the folds of the metal.

The resulting thread protector,` in the form of a generally cylindrical metal shell having one end open andv the other end closed, or partially closed, is characterized by longitudinal folds in the side wall of the shell that begin at the open end thereof and terminate short of the closed or partially closed end thereof. The thread protector is also characterized by a liner that covers the interior surface of the metal shell and that is gathered or bunchedv between the folds in the side wall of the metal shell so as to be securely held against removal or slippage with respect to the metal shell.

Further objects, advantages and features of the invention will become apparent from the following more detailed description of an illustrative form of the device and a' preferred method of making the same, and fromv the accompanying drawing in which- Figure 1 is a plan viewyof the threaded end of a length of pipe with a thread protector embodying the present invention applied thereto, portions of the thread protectork and pipe being broken away to show the interior construction of the thread protector and its relationship with the pipe;

Fig. 2 is an end elevation of the thread protector shown in Fig. l, looking at the open end thereof with the pipe removed.

Fig. 3 is a fragmentary longitudinal section through the thread protector of Figures l and 2, the plane of the section being indicated by the line 3-3 in Fig. 2; and

Fig. 4 is a vertical section through a die and punch assembly for forming thread protectors of the type il lustrated in Figures 1 to 3 and showing sheets of metal and lining materials in. position for stamping blanks therefrom and showing folded blanks of the metal and lining materials as they appear in the die assembly at the conclusion of the forming operation.

Referring first to Fig. 1 the protector cap of the invention preferably comprises a generally cup-shaped metal shell 10, entirely open at one end and at least partially closed at' the opposite end by a radially inwardly directed end wall 11. The end wall 11, in this instance, is shown as having a large aperture therethrough so that this wall, in effect, takes the form of an inwardly directed annular ange. f

Completely covering the interior surface of the shell 10,v including the interior of the end wall 11, is a liner 12 that is preferably formed from a relatively soft, compressible or deformable, and substantially inelastic sheet material, such as kraft paper, paperboard, a plastic film, sheet lead, sheet aluminum, or the like. This liner is preferably sufficiently soft to permit the shell to be forced over the threaded end of a pipe 13.

This composite cap of metal and soft lining material is preferably formed from at sheets in a single stamping operation, ask hereinafter more fully described. The manner in which this stamping operation is performed avoids any substantial drawing of the metal and shapes'r the flat sheet materials by folding them as they are drawn snugly around'the sides of the mandrel or stake of a suitable die assembly. As best shown in Figs.,1 and 2, the folds.14` begin at the open end of the cap and extend in an axial direction inthe side wall thereof, terminating short of the closed or partially closed end of the cap. Because of thesymmetryfof the forming mechanism, there is generally some semblance vof regularity in the size, shape, and spacing of the folds 14, but precise regularity is not particularly sought.

The nature of the individual folds 14 may best be described as double reverse bends. Considering any one of these double reverse folds, as viewed in Fig. 2, an outermost cylindrically curved metal portion 16 is first reversely bent back upon itself to form an intermediate fold section 17, which is then bent back upon itself a second time to form an innermost cylindrical portion 18. n

Now, considering the next adjacent double reverse foldA ineither direction from the one first considered, it will be observed that it is formed in the same manner as the first but that each bend is directed oppositely tothe corresponding bend in the'first, folding of alternate double reverse bends around the cap are the same and the folding of the intermediate double v reverse bends is in opposite directions.

The lining material 12 is somewhat similarly folded, to a degree, but the folding of the liner is generally so Virregular as to present no clearly discernible repeating pattern. In the course of the folding operation, the nonresilient, soft and compressible lining material is forced to conform to the interior contour of the metal shell, being hunched or gathered in a rather highly compressed condition into all of the spaces between adjacent vfolds of the metal shell. The interior surface of the liner is relatively smooth and is more accurately cylindrical than either surface of the folded metal shell, -but is covered with an irregular pattern of tightly compressed creases predominantly running generaly axially thereof and producing only slight surface indentations and ridges, ras indicated in Fig. 3.

The packing of the substantially non-resilient lining material tightly into the spaces between folds of the metal shell causes the liner `to be firmly gripped thereby and held in place.

hesive between the metal and the liner.

The finished cap should be somewhat larger in its inl-i side 4diameter at the open end thereof than at the opposite end to produce a taper more or less conforming tothe normal taper of pipe threads.

metal shell. The rigidity of the cap is increased by the longitudinally extending folds in the cylindrical side wall of the shell, and these reinforcing foods contribute materially to the force with which the cap grips the end of a pipe or tube to which it is applied.

According to the invention, the above described cap -and the liner forming a part thereof are formed in their assembled relationship by a single stamping operation. Suitable stamping tools for this operation essentially comprise a die 21 having a cylindrical opening 22 therein; an

annular punch 23 having cylindrical inner and outer conii-'tours and adapted to move into the cylindrical die open vPatented Feb. 8,11955 Thus, the directions of v However, if desired, this gripping action may be supplemented by the use of a thin layer of :id-.1

This taper may be contlnuous from end to end of the cap or may start at a ing 22`with small"cle`arance` for shearing discs from sheet material-passed-betweenthe-dieandthe-punch;a-tapeied` generally cylindrical stake or Amandrel 24 concentrically disposed within the die opening 22 with the upper end of tliewmandrel disposed slightly below; the upperwend'lof the-*die :opening 22'; and an iinner punch .'26 :concentrically mounted=withiri'thefffirstiimentioned,V p unchl':y In the. eventi. vra cap :havin g f acompletely Iclosed i end is desired, the :inner punch ,26fmay-be1ornittediand. the mandi-ell 24ey whic'hfis'lshown withfafcentral borewZf'-'for accommodating the'inner-punch26, -maybe made as-a;solid lpiecez.

These tools may be-'assembled upon la base 343;,7 the mandrel 24-being outwardly- 1 flanged.' at its lower Aend' to provide al seati f31frf forr the die 2liL The seat 1.31:'fis; =pro t vided withfa pa-ir of apertures'- 32 at` diametrically opposite,` v pointslfor accommodating a p luralityof pins `33 imountedi therein for vertical'lslidingmovementand preferably. urged upwardly lint a well'knoww manner fby suitable I springs orf hydraulic oushioningmeans; (not shown).- The upper ends=fof= the lpins 33 V"bear-,against an ejecting ring Vv311i thatis=- disposedz withinv the die 21'y and surroiindsf'the` mandrel' 24-with a-fieesliding'iit; The ejecting ring v3141is normally. urged upwardly bythe-Springactuated pins 33 andv is heldfwithan'lannular shoulder 3i6l`on^fthev ejeeting ring-y inengagement".withY an` interior annulareshoulder 37 l of theidief- 21;

The outer contourof .the mandrela24-is-icylindr`ical overy most ofits=lengthfbut"tapers'from a point to -the upper end'thereofftoprovide substantially greater clearance betweenthe*y mandrel andthe inner vcylindricall surfaceof the punch 23\"at the -upper end ofl the mandrel than-below'the poir'it38 whereithe taperbegins 1 The=innerpunch 26 and theouter punch `23 are rigidly mountedy for movement together, and a sleeve 41'isA slidably mounted. around the inner` punch 26` and vinsidethe outer punch 231 Thefsleeve 41"is-normallyheld'downwardlyiwithzits lowerend: even; withthe lowerend of the outerpunch-ZS in any/suitablel manner, las lbya spring or"hydr'auliccontr.ol ('not shown),- so that'thesleeve4'1 engages` the'. work' at: the same .time as the louter punch 23 and movesitherewith` duringthe-i'rst punchingvoperation `and until punched i discs. are carriedV1 downwardly against. the end kof thefmandrel 24. The sleeve 41`is.then stopped andserves' to holdthe punched discs rmly inV placet againstthemandrel during the remainder of 'the punching andlformingoperation.

metal sheetf43ffand'- a sheet oflining material 44` disp'osed'together in` superposed .relationshipare yfedi over th'ewdi'e opening 22. These sheetsmaybe adhered; to-

gether byia.. suitable adhesive or may be merelyv fed .to-

gether. asrdesi'red. When the punchassembly is lowered, theouter punch,v 23 severs-.di'scs.;from themetalsheet 43"` and the liner sheet 441simultaneously,.and the outer punch 23' and sleeve 441 'move the severed. discsdownwardly. onto the mandrell 24 vwhile'the die 212 maintains the discs in registry: The 'sleeve 41exerts a constantdownward pressure against the discs opposite the periphery ofl the upper end'of the mandrel as the downward movement ofthe. outer die 23 "is continued toV the lowermost position, illuS- trated in Fig. 4; DuringA they latter part of this move,- menttheinner punch 26'punches an aperturethroughboth of "the discs, and the severed blanks drop downwardly through the hollow mandrel and out of the die` assembly. Iii'the'eventyan aperture.. inthe end ofthe cap isnot desired',- a solidimandreliis employed and the inner punch 26 'is omitted. In this case, a. solid rodis preferably substituted' for the 'sleeve 41V so that the pressure applied to the metal sheet thereby will' be applied `entirely over the upper endof thezmandreli The^minmum-cl`earance"between the outer punch 23 and; the" mandrel 24` below the. tapered portion of the mandrel should beat least three. times the' initial thickness'of the metal sheet 431 The-clearance abovethe point 38fwhere the taper-ofthe mandrel begins; is substantially greater lthan the' minimum gclearance, as. illustratedin Fig. 4: With this large-'clearancebetween theouter punch 23- andthe mandrel y241, little drawing'of the discs is -effected as they are formed over the mandrel 24. Since'the forceexerted-upon` the upper surfaceofl themetal discy by the outer; A'punch 23 is vsubstantially uniformlyV distributedl entir'el'y around? its periphery throughout the forming ope-ra tion; the' metal tends toxfold in th'ef'manner"describedv` above-andl shownin: Figures: l-and 2, andthe lower edges: 4'and'f4f'of the resulting-capa'lie-almostfinthesame plane. The l'owerf innenedgefoff-'the *punch 21tr-isf:preferablyvv rounded, as shown at 49, to slide smoothly over the metal being Vformedasth'e"direction of'tl'ie force ofthe die on the metal being formed is directed more and more in a radially inward direction as the rounded edge of the punch passes downwardly over and beyond the periphery of the partially formed cap.

As long as the minimumclea-rance between the outer punch 23 andthemandrel24,below the Ataperiofthe mandrel does not exceed'three times the initial'thickness of themetal sheet-,43,v theu folds; in the` ,.sidesof, tlregmeta-15,1h

s hell will,be ,tightly/creas ed,-.` as 'shown in Eig-2g anllthe lining material will be tightly packed and compressedso as to completely fill the spaces between adjacent folds in the metalshell;

The clearance between the inner punch 26 and the bore 27 of the mandrel"24iis'fpreferablyslightly greater than that required to produce a clean shearing cut. As a result, the inner edge of the ange 11 of the metal shell is-:turneddo'wnwardlyover-the adjacent Yedgeofthe liner, y as-v showfnat..48.^` ThisA provides Ianv additional"'barrierl againstY slippage-of-therliner :withinF the meta-l shellf? Where ranaperti-irein the: endofl the cap Ais desired; 'the diameterfof Cthealiierture is preferably'.y `selectedslightly e larger than the interior diametreoffthe *pipe* to which' the" cap vis'to lbe'applie'drv This prevents the-cap from obstructingfthe-interioif-boie ofthe pipe to any degree andlpermits. various^operatioiis to 'beperformed upon'the interior of" thepipefafterit-has.been `threadedand the capA hjasbeeri applied over the threads;

Uponwithdrawal of* the punch assembly fromthediey 21,- thee1ectorrring34 follows the punch23upwardly until theshoulder '36 of theA ring engages the. shoulder 3T of'thedie.' During-upward movementjof'the ring '.i'lity engages the flower edge 46v ofthe metalshell" of theA cap and lifts the cap upwardly` Oithe m andre.l"24.A Thisk frees the finished 1'cap so Vthatitcaribet lifted "o ut ofthe die'21feither manually or mechanically, Aas desired.'

The' particular embodimentsofthe invention shown and described in, detailihereininvolve caps ,having theI generalilshape,` of; a circular cylinder vvthat is, 'formed'L from z discs (circular plates) of"metaLandjjlinitig material. Itf will be apparent, however,thatcaps having ovalgipolygonal,` or other cross-sectional outlines,l may readily be. formediin the same .manner from,..appropria1tely shaped,

plates ofmetal vand'liningmaterial; Suchother shapes.

are desirable for applicationloithe endsl of correspondingly shapedrods,tubesand the jlike.- A

Accordingly, ini this specification. andin the ,appended glaims, unless. the kconteiitotherwiserequires the vterm cylindrical, is intended'L tol be construedin its: broad` geometricalsense and to cover the various shapesgemV erated by a straight linegeneratrix as. it moves,normal` to itself along'k av closedlpath;whether oval,- elliptical, polygonaL: or irregularA inoutline.

The ythread protectors .manufacturedinaccordance, with:

the`.present invention may be applied overthecnds ofI either threaded or Unthreaded 'pip,e,s, rods,l tubesor. the

like,` andiwillrmly. grip the ySameandbe retainedLsecurelythereon.V They. may. beiappliedina simpleiman-l-- ner. by merely jamming them over the. ends of: members Atobeprotected, either manually, preferably usinggamallet pending application, Serial No. 85,580, ledAprilS, 1949,`

for a Thread and Tube Protector, now abandoned;

Havingrdescribed, my invention, I ,claim;

l. AA thread protectory comprisingl an outerl cup-shapedg. metal .capof generally cylindrical .for.m;havingf;a ,plug

rality ofi double :reverse folds', in the side walll 4thereof. spaced. circumferentially 'around-.the cap; and extending.

longitudinally' thereof, anda a; continuousl liner of ,a rela'- tively soft sheet material covering the inner- .;surfaceroh.

said cap and having portions bunched between and tightly gripped by adjacent pairs of said folds.

2. A thread protector comprising an outer cup-shaped metal cap of generally cylindrical form having a plurality of double reverse folds in the side wall thereof spaced circumferentially around the cap and extending longitudinally thereof, and a continuous liner of a relatively soft sheet material covering the inner surface of said cap and having portions bunched between and tightly gripped by adjacent pairs of said folds, the side wall of said cap adjacent the closed end thereof being tapered toward said closed end.

3. A thread protector comprising a generally cylindrical metal shell having one end open and the opposite end partially closed by a flange extending radially inwardly, the generally cylindrical wall of said shell having a plurality of axially extending double reverse folds therein, said folds beginning at the open end thereof and terminating short of the partially closed end thereof, and a continuous liner of a relatively soft sheet material covering the interior surface of said metal shell and being bunched between and tightly gripped by adjacent pairs of said folds.

4. A thread protector comprising a generally cylindrical metal shell having one end open and the opposite end partially closed by a flange extending radially inwardly, the generally cylindrical wall of said shell having a plurality of axially extending double reverse folds therein, said folds beginning at the open end thereof and terminating short of the partially closed end thereof, and a continuous liner of a relatively soft sheet material covering the interior surface of said metal shell and being bunched between and tightly gripped by adjacent pairs of said folds, said ange having an inner edge turned inwardly in an axial direction over the adjacent edge of said liner. y

5. A thread protector comprising a generally cylindrical metal shell having one end open and the opposite end partially closed by a ange extending radially inwardly, the generally cylindrical wall of said shell having a plurality of axially extending double reverse folds therein, said folds beginning at the open end thereof and terminating short of the partially closed end thereof, and a continuous liner of a relatively soft sheet material covering the interior surface of said metal shell and being bunched between and tightly gripped by adjacent pairs of said folds, the generally cylindrical wall of said shell being tapered for a portion of its length adjacent and toward the partially closed end thereof.

6. A thread protector comprising a generally cylindrical metal shell having one end open and the oppositie end partially closed by a iiange extending radially inwardly, the generally cylindrical wall of said shell having a plurality of axially extending double reverse folds therein, said folds beginning at the open end thereof and terminating short of the partially closed end thereof, and a continuous liner of a relatively soft sheet material covering the interior surface of said metal shell and being bunched between and tightly gripped by adjacent pairs of said folds, the generally cylindrical shell, adjacent the partially closed end thereof, being tapered inwardly toward said ange, and said flange having an inner edge turned inwardly in an axial direction over the adjacent edge of said liner.

7. A thread protector comprising a generally cylindrical metal shell that is substantially circular in cross section and is at least partially closed at one end by a radially inwardly extending wall and open at the opposite end, the generally cylindrical wall being longitudinally folded into tightly creased double reverse folds at a plurality of locations spaced around the circumference thereof, alternate ones of said double reverse folds beginning with a fold under and circumferentially back in one direction, and the remainder beginning with a fold under and circumferentially back in the opposite direction, and a continuous liner of relatively soft sheet material covering the inner surface of said shell and adhered thereto, said liner being bunched into compressed portions filling the interior spaces between adjacent oppositely bent folded portions of the shell and being tightly gripped thereby.

8. The thread protector of claim 1 in which said liner is adhered to said metal shell.

References Cited in the iile of this patent UNITED STATES PATENTS

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