US2641303A - Method of making flexible hose - Google Patents

Description

June 9, 1953 J. E. VANCE 2,641,303

METHOD OF. MAKING FLEXIBLE HOSE Original Filed June 14, 1949 2 Sheets-Sheet 1 mi'sm'on. John L. Vance BY I D fi/ ATTORNEY.

June 9, 1953 J. E. VANCE 2,641,303

METHOD OF MAKING FLEXIBLE HOSE Original Filed June 14, 1949 2 Sheets-Sheet 2 4 mwmron.

John 1!: Wm:

Qy-Y

ATTORNEY.

Patented June 9, 1953 METHODZOF MAKINGFLEXIB'EE HOSE.

John: Vance, North Canton; Dhio assignor to; The HoovcroGompany, NosthefiantomwOhiO -{aw corperation'of :Ohi'o;

Original application" Jime 1'4, 1949, Serial "No; 98,920; Divi'cledhncl this application March 16, 1951; Seri'2'ti N0."215',945

s .C-la'ims. (CL-:154-8) This inventionirelatestoilexiblehose for suction cleaners and to the method of making the same;

The presentapp-lica-tion is e, division of my "application; Serial No. 98-,9'20gfileqilune le, 19'4'9, Patent No. 2,550,099;datednp-ril-z l, 19511 7 parent application-claims the hose p'er se -while The this application is drawn to the meme: of mak ing the'hosei A" suctioncleaner hose must be-'a-s= flexible'-as possible for ease in manipulating-the cleaning tools ;'it must be rigid'again'st compressivestresses so as "to resist coliepsewvhen accidental-1y "trocl 'upon' or placed beneath articles of furniture-and "th'einrpervious Wall must be'supportedega-inst collapse duetmthesuction applied on its interior.

According to the present invention the thin impervious tlibecomprises" amelastomeri-c 'thermoplastic, such aspolyvinylchiorid'e'or copolymer'ofvinyl, of'about0.'026 inchfiir'thiokness'and about 1% inches inside-diameter: 'A' spirally wound reiniorcin'gwire' of spring" steel is posttioned interiorly of"the-tube "and-"an elastomeric thermoplastic cord is wrapped spirally over the tube between the -conv'o1ution's of the "wirenmder constant tension suflicient toorawthemateril of the tube inwardly between the wire convolix tion's "so' as to "render the" completed hose more According to the method of this invention the "steelspringis spirally woundfin' 'sliitableflength's 'with'epitch of'substantiaily A; inch: Thespri'ng isspreferably originally Wound. on "a; mandrel of :somew'ha't smaller diameter thantherdiameter of [the desired "coil." (In makmg'sucti'on'clea'ner iiose f' it been "found that af'fi'nail inside "diameter-of approximately 1% inches "is suitable). thecoil is .relea'sed'it will expand tbth'e properv -Wh'en diameter-under'itso'wn'resiliency:

The spiral spring fthus iforme'ofisplaced on a mandrelhavinga: diameters few thousandths 'ofaninch'smaller than the free 'insidedielmeter 0f the coil and one end taped to I the mandrel,

'or *'to" a" fitting sleeve-anchored to "the mandrel, preferably by a pressure sensitive tape: "The pitch of "the coil 1 in its freesta-te is slightly- 'l'ess than it is inthe-"finished lios'e -ss' is tlie member "of-it's convolution-s;

A spacing tool isthen applied "to tlie taped end of "the e oil and the mandrel 1 rotated reverselyto expandthe pitcl'i' df the'coiis axially 'and to'spaee *them"-equidistant and-to tightly griii' the mandrel *while at the same 1 time --ti ie tool -.a;ppl-ies==:a fcon traictingieifeot spiralty upon the :coilstasFtheware 'xspac'ed to' mnd thezcoiis closely aboutsitheaman- -si'oningdevice so that i when the txibe dtel: with :the resutt that :there is sabgi'eatera mime bcr ofi'loops'formedzthan that which-wasmresent in the coil .in: itsr free state. Theacombined efiect .of s'spacing the :coils augreater 'distanceaapartand 'the -"formingiof additional loops-cause the coils to itightly grip: thegmandrel son-that :each loonis sub'sta-ntiatll'y immovable axially of .vthezmandrelz After theispac'ingaoperation lthe othemendnof the coil is suitably attachedjto. thezmanclrel lorz to 'a oouplingvfittingztub;positioned on the mandrel.

Ana elestomeric thermoplastic; tube is then appliedz-oyerlthe mandrel andLSpringt-in any able "manner,- such was r by; expanding; it ,vibygaiir press uirep-and. .&s1i'ding .=;it axiallyvoverrthe mandrel andithe: spiralcspring ositioned thereon.

few turnssofzthe-yinyl norct amezzthen wmppfid bwhan d -oyerith'e avinyl tube-wait one. end.-iimidway of thev'conyolutionsrof the wire. amivtapeehto the tubepreferablyzby atpi'essurefsensitivea tape: The

mandrel, wire, and tube are then'. .rota;ted;:-while 'a tensioning 'devicexholdingthe acord :isrnzdvanced axially "to nwindttheword about thestubezmidway of thew-wire convoiutionsr. Whenz-thes-cond apply -ing operation is completed the sine; BIIdiOf i the eorct islseverezzl-"emt taped .to theztubeat theaotbier end by means hint-pressuresensitwettape.

Preferablm'a suitable solventiszsimultaneously eord during the vtrinningoperattionntorlzromi the word to the -tube midivayof. the wire convolntirms sa that the cordmannot bemovedifromzbetween oneiwire convolution toen iadjaeentaonetorivice "verse;v

The vinyl cord is stretched slightlyibystheitem 'iremoved from the mandrel tlie=coils=-of -th e vinyl-icord #will -co-ntrac=t-to=press the walls of the tubeiinwamdly "between" the '-Wire convolutions 1 to *form ar corn-1 gated "effect and render thetube more-flexible.

' -"the same 1 time the convolntionsxo-f the Wire will tenof-"to" return-to their original :pit-ch send number-1rso'ithat-the zcoils' 'will impanidmMtWardly by anaamount permitted;ibytthes:elasticity oitthe yinyltube andzcord.

The tube preferably extendsvbeyend ltneends of; the wireand vinyl cordzancl turned ..;backwardlyeovert-the tube- .and.,viny1 cord solasstmperr ;mit:an-attaching fitting to be applied. t

otherg objects and advantages .of this invention will become apparent .asithetdescrilitionyproneeds whenz-taken in v\c-onnection .with :the accom- Darryingzdrawingsin which:

Figure -.1 -.shows Jeschematic view ofsa machine :forwspacingsthe wireicoilssonrthe mandrel-anoint winding the vinyl cord about the tube;

II as shown in Fig. 4.

lar to an ordinary turning lathe.

Figure 2 is a detailed view showing the operation of the spacing nut;

Figure 3 is a plan view of the spacing device showing how it is mounted on the machine; and

Figure 4 is a longitudinal cross-sectional view through the tube of this invention showing one form of an attachment coupling applied thereto.

Referring to Fig. 4 the hose of this invention comprises an inner spirally wound spring wire stressed axially and spirally from its normal unstressed state, an elastomeric thermoplastic together and to the support 48 at 50, the lower vinyl tube l l positioned thereover and forced between the convolutions of the wire ID by a spirally wound elastomeric thermoplastic vinyl cord l2.

The end connection for the suitable form but as shown in Fig. 4 comprises an inner swivel tube l3, an outer swivel tube l4 having a swivel connection with the inner tube [3 generally indicated by the reference numeral l5 in the form of inwardly pressed annular grooves in the tubes. The end N5 of the wire In rests in the groove of the outer swivel tube l4. The few end turns of the wire ID are secured to the tube l4 by a pressure sensitive tape l1 spirally wound over the wire. Near its end the tube II is anchored to the tube l4 over the end l6 of wire 10 by waxed threads 8. The threads l8 and the end coils of the cord 12 are secured to the tube II by a pressure sensitive tape [9. The end of the tube 1 l is then turned 'backwardly over the threads 18, tape l9, and the first few coils of cord [2 and a phenolic or other plastic sleeve 2| attached to the inner swivel sleeve l3 so as to surround the end 20 of the tube It is within the scope of this invention that other types of end couplings be used, the one of Fig. 4 being shown as an example.

The hose of Fig. 4 is formed by any suitable apparatus such as the machine of Fig. 1 generally indicated by the reference numeral 30, similar to a turning lathe. The machine com prises a bed plate 3|, a head stock'32, a tail stock v33, a lead screw 34, and a traveling carriage connectible to the lead screw 34 by a manually actuatable clutch 36 in a manner simi- The driving mechanism for the head stock 32 and for the lead screw 34 are geared to both in a manner similar to an ordinary turning lathe. A mandrel 31 is rotated by the head stock 32 and is rotatably mounted by the tail stock 33.

The carriage 35 carries a coil spacing device generally indicated by the reference numeral 40,

a reel holder 4| for carrying a reel of vinyl cord, a tensioning pulley 42, and a cord tension measuring device 43. Carriage 35 is also provided with suitable guide pulleys to guide the cord from the reel 4| to the tensioning pulley 42, from the tensioning pulley 42 to the tension measuring device 43 and from the tension'measuring device to the mandrel 31. The tension measuring device 43 includes a clocklike dial and hand which register the tension on the cord to constantly inform the operator of the tension applied. It has been found in the example given that a tension of 56 to 64 ounces is satisfactory for the conditions specified.

The spring spacing device includes a sort of nut 45 split axially to form two halves 46 and 41, the lower half 46 being secured to the traveling carriage 35 by means of a supporting hose may take any half 46 being slotted at 5i on the side opposite the pivot 50 to receive a clamping bolt 52 pivoted to the upper half as shown in Fig. 3.

"The carriage 35 may also carry a solvent applying dispenser in the form of a container 53 as shown in Fig. 1 having a valved tube leading to apoint immediately above the mandrel at a point a few turns ahead of where the cord is wrapped about the mandrel. The solvent used may be a 50-50 by volume mixture of toluene and methyl ethyl ketone.

Method of forming ho se A steel spring wire of suitable diameter is spirally wound into a coil of substantially the same internal diameter as the diameter of mandrel 3! and with a pitch slightl less than that of the wire I0 in the finished hose. The wire is preferably wound on a mandrel slightly smaller than the mandrel 31 so that when it is released the coils will expand to the proper diameter and pitch.

It has been found in practice that a wire having a diameter of {0.058 inch and a tensile strength of 275,000 pounds per square inch is suitable. The free diameter of the coil should beclose to 1% inches and have a pitch of approximately /4 inch.

Coupling sleeves similar to the sleeves l3 and I4 are positioned on the mandrel at the head stock end thereof. The wire coil is placed on the mandrel 31, which in practice is approximately 1% inches in diameter, the sleeves l3 and I4 slid onto the tail stock end of the mandrel beneath the wire coils with the end coil [5 posi-- tioned in the peripheral groove l5, it being noted, Fig. 4, thatthe inside diameter of the inner end of tube [4 is substantially the same as the inside diameter of tube [3 whereby they can be positioned on the mandrel. The wire In is taped to the sleeve M by the pressure sensitive tape I! at the tail stock end thereof and the sleeves l3 and I4 anchored against rotation relative to the mandrel.

The turns of the wire on the sleeve and the first few turns on the mandrel are suitably spaced by hand or otherwise and the spacing nut 45 arranged over the turns with the wire lying" in the spiral grooves 49. It has been found in practice that the pitch of the spiral grooves in the nut 45 should be about 0.286 inch when the normal free pitch of the wire coils is inch.

The diameter of the spacing nut and the depth of the grooves 49 is such that the nut will grip the wire coils quite firmly when the bolt 52 is clamped.

After the nut 45 is applied to the first few coils of wire positioned on the mandrel at the tail stock end, the clutch 36 is manually operated to engage the carriage 35 with the lead screw 34 and the head stock 32 rotated forward or counterclockwise as viewed from the tail stock end.

Such rotation of the mandrel will cause the coils to be spaced uniformly thereon and the gripping action of the nut will also deform or stress the coils circumferentially so that under #15 -the eonditions given aboveth'ere will' be appr'o'xiemately one percent more "coils formed ion ithe l mandrel than there areiin the coiled wireimits unstressed state. The foregoing action will wounditoipermitiitheisurfaceofztheitubertozsetten sufficientlyithat-fthe"cordrwillfnrmly 'aidherestorthe tube as itfiis wound aboutiit.

The "tail'stock t3-isa'agaim removed and thifin- 'cause-ithe' coils to grip'ithe mandrel tightly-s that ished tubing* 'removed*from theimandrel 31 -iby l t-hey will 1 not move dtiring: the" subsequent ap- :iplication of the elastomeric thermoplastic 5 vinyl 'tube. When the spacing nut reaoh es thefi-left L: hand-end of r'themandrel, tothe sleeve positioned mapplying; a," 'twistingfaaction im'a-zdirectionito ex- "pand the coils. I 0 whereby ithel'f'finished tube can be slid backwardly 'ofi "the tai1' st0ck" ?endfIof the mandrel 31.

fithereom the few endturns' of the 'coil'ed wirezare l0 Theetension applied"to the cord l2 w'ill force tightly taped to a "sleeve' l 4 by"pressure sensitive tape and "the sleeve "claniped to bhe mafidleliiin '-any suitable mannen v Tail stock- 335 maythen be removed" and" a vinyl tube applied 'by 1 air "pressure" in a manne I vance and male C;"Gerber, SeriaI NOT- ZB'T; "4, :filed 'November -"22 1047. According to i that"a'pplication a tapered sleeve'-having an lnside dithe walls of itheirtube- '-l I' 'inwardly between the "convolutions bf the wire -I 0. 1 Ad'ditionallm-" the wire spiral I0 will t'end to return to-its original pitch *and' diameter so as to force the tube =I I disl5 outwardly between the convolutions of the cord los'ed in-a copendingapplication bywJohn E. v

'- 12 adistancepermitted by the elasticity-"'ofthe tube wall and of the cord so as'td forma very flexiblehose.

'Iheencl""couplings' 2I may then be applied-etc ameter of a size' suitable' to slide over 'the'coiled'i flo each end of the 'hose' imany" suitable manner,

The-air pressure-expands the tube suflicientlyi:

that it can be slid axially over the coiled wire positioned 'onjthe mandrel. ZItiiSf 'GO :be :notedzfrom Fig. 4 that-thelength-.ofethetube II should be greater than that of the coiled wire on the mandrelt'by an amount sufficient to form the-back? wardly extendingportions at eachend.

An alternate method is tom'ake the' mandrel "3 l'" hollow and apply "air" pressure to theinterior *"there'of through thehead' stock 32 and "plugthe pand the tube sufficiently that it can be slid over the coiled wire.

It has been found that a plastic tube, having a wall thickness of 0.026 inch, formed of elastomeric thermoplastic vinyl having a minimum tensile strength of 2,000 pounds per square inch at 80 F. is suitable.

The tail stock 33 is then reengaged with the mandrel 31, the first few coils of the cord I2 wound over the tube II and sleeves at the head stock end of the mandrel midway between the convolutions of the wire I0. The end of the tube H is also rigidly secured to the sleeves and the wire It by means of waxed threads I6. The first few turns of the cord I2 and threads I8 are taped to the tube II by pressure sensitive tape I9.

It has been found that a plastic cord of elastomeric vinyl having a minimum tensile strength of 2,000 pounds per square inch at 80 F. and a diameter 0.075 inch is suitable.

The tension on the cord is properly adjusted by adjusting the tensioning pulley 42, which tension will be registered on the tension measuring device 43. The clutch 36 is then manually operated to engage the carriage with the lead screw 34 and the head stock 32 rotated backwardly or clockwise as viewed from the tail stock end so as to spirally wind the cord over the tube I I midway between the convolutions of the reinforcing wire Ill from the head stock end to the tail stock end of the mandrel 31. The-"end coils of the cord are then taped to the tube II by a pressure sensitive tape I9. During the winding of the cord I2 about the tube II the valve in the solvent dispensing tube is properly adjusted to apply the proper quantity of solvent two or three coils ahead of the cord as the cord is wound about the tube. The solvent is applied sufliciently ahead of the point where the cord is being note" beingt'a-ken that the *er'id20 of "the tube I I is turned backwardly' over" the-"- end" 'coils' iiffthe cord-1'2. I

'Elastomeric thermoplastic""materials as 'such ""areold and well known andaremade by-mixing a thermoplastiwresin' with a "plasticizer. ""At ordinary temperatures they are] slightlyfelastic "in that the'm'aterialcan-be stretchedr'somewhat 'and"will return wh'en'release'd. Ifthe material remains in 'istretch'ed condition 'iit' will "remain under a definite'tensi'on.

' While I have 'shownand described'but' arsingle embodiment ofmy"invention itisto"be'under- '"stood' that this embodiment is "to be .takemasillustrativeohly and "not'in alimiting sense. Ido not wish to be limited to the particular structure shown and described but to include all equivalent variations thereof except as limited by the scope of the claims.

I claim:

1. The method of forming a flexible hose comprising, winding a spring wire into a cylindrical spiral having a given pitch and diameter, applying a stress axially and circumferentially successively to the coils of said spring from one end to the other to increase the pitch and number of the coils in said spiral, holding the coils of said spiral in their stressed position while applying an elastomeric thermoplastic tube over said coils having the same internal diameter as the unstressed internal diameter of said coils and spirally winding a tensioned elastomeric thermoplastic cord over said tube between the coils of said spiral while it remains in its stressed condition, anchoring the ends of said spiral coils and tube to each other while under their stressed condition and releasing the stress on said coils to place said cord under a circumferential stress, said tube under an axial stress,-said spring remaining tensioned axially and circumferentially.

2. The method according to claim 1 including the step of applying a solvent for the cord and tube as the cord is wound about said tube.

3. The method of forming a flexible hose comprising, winding a spring wire into a cylindrical spiral, anchoring one end of a coupling sleeve interiorly to the first few coils of one end of said spiral, applying a stress axially and circumferentially to the coils of said spring successively away from said sleeve to increase the pitch and number of said coils, anchoring a sleeve interiorly to the first few coils at the other end of said spiral, holding said spiral in its stressed condition while applying an elastomeric thermoplastic tube thereover having an internal diameter substantially the same as the internal diameter of said spiral in its unstressed condition, anchoring the end of an elastomeric thermoplastic cord to one end of said ,tube, spirally winding said cord under tension over said tube between the convolutions of said spiral while said spiral is maintained in its stressed condition, anchoring the other end of said cord to said tube and releasing the stress on said spiral. a

4. The method according to claim 3 including the step of simultaneously applying a solvent to said tube simultaneously with the spiral winding of said cord about said tube at a point spaced ahead of Where the cord is wound about the tube to permitthe surface of the tube to soften sufli ciently for the cord to adhere to the tube as it is wound about it. 7

5. The method according to claim 3 including the step of applying a solvent for the cord and tube to the tube beneath said cord. v

6. The method of forming a flexible hose comprising, winding a spring wire into a cylindrical spiral having a given pitch and diameter, successively spacing the coils of said spiral axially and simultaneously applying a circumferential stress to the coils of said spring from one end to the other to increase the pitch and number of the coils in said spiral, holding the coils of said spiral in their stressed position while applying an elastomeric thermoplastic tube over said coils having the same internal diameter as the unstressed internal diameter of said coils and spirally winding a tensioned elastomeric thermoplastic cord over said tube between the coils of said spiral while it remains in its stressed con- 'dition, anchoring the ends of said spiralcoils and tube to each other while under their stressed ;eter as the unstressed internal diameteriof said coils and spirally winding a tensioned elastomeric polyvinyl chloride cord over said tube between the coils of said spiral while it remains in its stressed condition, anchoring the ends of said spiral coils and tube to each other while under their stressed condition and releasing the'stress on saidcoils.

8. The method according to claim 7 includin the step of applying a solvent for the tube'and cord to the tube beneath the cord.

JOHN E. VANCE.

References Cited in the file of this patent- UNITED STATES PATENTS Number Name Date 2,160,371 Schnabel May 30, 1939 2,176,762 Forbes Oct. 17, 1939 2,262,861 Rugeley et a1 Nov. 18,1941 2,377,316 Billmeyer June 5, 1945 2,560,369

Roberts July 10, 1951

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