US2038745A - Method and apparatus for forming conduits - Google Patents

Description

pxrl 28, 1936. E, D L OWRlE 2,038,745

f METHOD AND APPARATUS FOR FORMING CONDUITS Filed April 12, 193 2 sheets-Sheet 1 I 11m u Tr'l'l' v ATTORNEY E R W O L D. E

METHOD AND APPARATUS FQR FORMING CONDUITS Filed April Y 12,. 1952 2 Sheets-Sheet 2 Hg Z.

A TTORNEY Patented Apr. 28, 1936 UNITED STATES PATE OFFICE METHOD AND APPARATUS FOR FORMING CONDUITS Application April 12, 1932, Serial No. 604,695

16 Claims.

This invention relates to new and useful irnprovements in a method and apparatus for forming conduits and more particularly automotive brake cable conduits.

An important object of the invention is to provide a method and apparatus which will continuously form conduit material without requiring manual handling from the time it enters the apparatus until it emerges therefrom in the form of completed conduit material.

Another important object of the invention is to provide means for forming a leakproof covering upon the metallic conduit usually employed for the guidance of exible brake cable whereby lubricant provided in the flexible metallic conduit will not escape through the Walls thereof nor will the covering permit the entrance of extraneous material into the flexible conduit.

A further object of the invention is to provide means for braiding a fabric tube upon the iiexible metallic conduit and for giving the' same successive coats of liquid coating composition in rapid succession, there being provided means and arrangement between successive stages of coating for proper treatment of the previous coating and preparation of the strands for subsequent coatings in a manner which precludes scarring or marring the previous coating imparted to the strand.

A further object of the invention resides in the provision of a drive mechanism for propelling the strand through the apparatus which will automatically become inoperative whenever the flexible metallic conduit ceases being fed into the apparatus or whenever the braiding machine ceases operation due to breakage of the strands of yarn or when the spools carrying such yarn require replenishment.

Other objects and advantages of the invention will becomeY apparent during the course of the following description.

In the accompanying drawings forming a part of the description and wherein like numerals are employed to designate like parts throughout the several views,

Fig. l is a side elevation of the apparatus shown more or less diagrammatically for the sake of clarity.

Fig. 2 is a vertical transverse section of the same taken on the line 2 2 of Fig. l.

Fig. 3 is a vertical transverse section taken on the line 3 3 of Fig. l.

Fig. 4 is a top plan of a series of liquid coating receptacles forming a part of the apparatus,

Fig. 5 is a vertical transverse section of the same.

Fig. 6 is a vertical section through the automatic cutoff for the braiding machine.

Fig. 'l is an enlarged perspective view of a .sec- 5 tion of the partially formed continuous conduit illustrating a portion of the same in an exaggerated manner to show the means by which the individual sections of metallic flexible conduit are united by the fabric covering material formed l0 thereon by the braiding machine.

Referring now more particularly to the draw ings wherein for the purposes of illustration is shown one form of the apparatus, the numeral i designates the usual electrically operated braidl5 ing machine mounted on a suitable platform 2 by a stand 3. As is well known in braiding machines, the table Il thereof is provided with a serpentine or sinuous track for guidance of rotary spool carriers, each of which carries a spool 5 of 20 thread or yarn. The threads- 6 from the individual spools converge upwardly as illustrated to be formed into a braided fabric tube as is well understood in the braiding art and therefore a detailed description of the braiding mechanism 25 per se will be omitted. The braiding machine is provided with a support 'l for a rotary sheave wheel S for guiding the strand 9 coming from the braiding machine upwardly over the same and thence downwardly under a second sheave wheei 30 It suitably mounted upon the platform 2. This platform is grooved so that the strand 9 can be guided beneath the upper surface of the platform so as not to interfere with operations around the braiding machine. As is customary, the 35 braiding machine is provided with an automatic cutoif which causes it to cease operation whenever any of the strands or threads 6 break or their supply from the spools 5 becomes exhausted.

In order to properly guide sections of flexible 40 metallic conduit material` II into the braiding machine, whereby such sections will be united and covered with a braided fabric covering, a guide tube I2, extends into the braiding machine beneath the table thereof to the center of the 45- machine where it is curved to extend upwardly, as illustrated, to a point above the tops of the yarn spools 5 and slightly below the point where the individual threads 5 converge together to form the braided tube or strand. As better shown in Fig. 6, the guide tube I2 adjacent its upper end is provided with a slot I3. Just below this slot is a bracket I4 pivotally supporting a bell crank lever I5 as at I6 with one arm thereof rotatably supporting the roller I'I which is 55 and Vmoving it outwardly. This engagement-ofv the arm 2| with contact I9 completesa circuit in the braiding machine which starts it in operation. The bell crank is of course suitably insulated from the bracket and is connected with wire 22 of the electrical circuit controlling the 'braiding machine so that when additional sections of metallic conduit are not fed into the guide tube and the last one has passed therethrough, the Contact roller I1 moves inwardly of the gui-de tube under the influencer of the spring I-B'and breaks the Contact between the arm 2I and the contact I9 to cause the braiding machine to cease operation. During the normal operation of the machine, the metallic conduit sections are fed into the lower end of the guide tube I2, one right after the other in twelve foot sections and with the forward end of each section engaging the trailing end of the preceding section or substantially so, whereby the contact roller I1 will not move into the guide tube and cut off operation of the braiding machine. As shown at Fig. 7 the various sections of the metallic conduit' are'united by the braided :fabricV covering or coupling 23 formed by the braiding machine as the sections pass through the same.

This fabric covering i's ofcourse of sufficient strength to withstand the pull or tension imparted to the strand as it is drawn through the apparatus in the manner now to be described.

- If desired, either sheavewheel 8 or II)Y may be driven by the braiding machine or any other suitable source toassist in feeding the fabricated metallic conduit or strand through the apparatus. After Ythe sectionsof metallic conduit, which usually consist of one or more spirally wound strands of metallic wire are united and Vprovided with Vthe braided fabric covering by the braiding machine to form a continuous strand, this strand isv guided as it comes from. under the platform 2, around an idler sheave wheel 24 suitably mounted inV bearings on a standard 25 of a suitably formed frame work 26, approximately 20 or 25 feet in height and made up of any suitable arrangement of structural elements. The sheave wheel 24v guides the strand 9 upwardly through a paint receptacle 21 and then through an elongated vertical tubular oven 28 which is supplied at its lower end by the conduit 29 leading from a thermostatically controlledv heater 30. This receptacle 21 is adapted to'contain a quantity of liquidV coating material, in this instance being a lacquer which will thoroughly impregnate and coat the fabric covering of the metallic conduit. ThisY receptacle 21 is suitably supported upon the standard 25 and its Ytop and bottom walls are provided with aligned apertures for the vertical passage of the strand 9. Surrounding the Yaperture in the bottom of the tank is an internalleakage of the liquid coating material from the bottom of the tank.

The top of the tank or receptacle 21 is provided with a ring 34 which forms a circular recess on top of the tank. Within this recess is a floating hub having an annular flange considerably smaller in diameter than the internal diameter of the ring 34, thereby providing a substantial clearance between these elements so that the hub can oat or move in all directions 'in a plane parallel with the top of the tank. This hub is provided with a bore therethrough, the inner end of which is restricted as illustrated, for the passage of the strand while the shoulder of this reduced bore forms a support for packing material 36 in the form of one or more felt Vwashers provided with registering openingsY for ter is prevented from becoming scarred by contact with the metal parts after receiving the coating material.

From this point, the strand 9 is moved vertically through the elongated drying oven 28, the

heated -air from which exhausts from the upper Y end of the oven by means of a by-pass pipe 38 which leads to a blower 39 from whence it is Y propelled through the by-pass pipe 49 into a secondary oven or drying chamber 4I. This by-pass 40 is provided with a control damper 42 Where- Y by the amount. and velocity of the heated airV may be controlled at will.V If desired, the bypass 38 may return to the heater 30 when it isVV not desired to convey the heated air to the sec-` ondary drying compartment, or the blower 39 may be provided with a. by-pass back to the heater 30 for passage of the warm air when the controlE damper 32 is completely closed.

After passing through the top of the oven, the strand 9,. is trained about an idler sheave 43 mounted in` suitable bearings atfthe top .of the supporting structure to guide the strand downwardly in the atmosphere between the two ovens to another idler sheave 44 loosely mountedvupon a transverse shaft 45 mounted in suitable bearings upon a leg of the supporting structure.

From this sheave 44., the strand 9 is directed inV 46 are provided in the main receptacle by Yequipping it with a series of partitions 41 as clearly shown in Fig. 4. The top and bottom of each of these individual paint receptacles is of thev same description as shown and described in Fig. 5 for the primary receptacle 21 and the same numerals to designate corresponding parts of the two receptacles have Vbeen employed in Fig. 4. Y

The strand after passing through receptacle 46 passes upwardly into the enclosed oven 4I to pass around a sheave wheel 48 loosely mounted upon a shaft 49 carried at the top of the supporting structure. A series of sheave wheels corresponding to the one 48 are loosely mounted upon the shaft 49 and a similar number of sheaves 44 are mounted upon the lower shaft 45 so that the strand can be guided from the rst sheave 48 downwardly to a second sheave 44, thence up through a second liquid coating compartment 50 containing a liquid coating compositio-n of different viscosity, thence up to the second sheave 48 of the series back again to the third sheave 44, thence upwardly through the third paint receptacle containing still a different grade of liquid coating composition, thence up through the drying compartment to another sheave 48, from whence it is directed back around the corresponding sheave 44 and thence upwardly for the final time through a paint receptacle 52 back to the upper sheave 48 from whence the strand, now containing 5 coats of liquid coating composition is directed to the strand propelling mechanism to be presently described,

The strand before entering the paint receptacle 46 has been dried by passage through the oven 28 and thence through the atmosphere so that it is ready to receive the second coat of material from the receptacle 46. The casing 4| is completely closed with the exception of apertures in the bottom of the casing extension for the passage of the strand, and a vent opening 53 near the top of the casing which may be damper controlled if desired. Within this casing is provided a separate compartment 54 the lower end of which communicates with the by pass 40 for concentrating the by-passed heated air around the portions of the strand which come from the first few paint receptacles mounted beneath the secondary oven. The compartment 54 may be larger or smaller to house a larger or lesser number of portions of the strands 59 which pass upwardly in the compartment and may be completely enclosed at top and bottom with the exception of openings for the passage of the strand or the compartment may be left completely open at top and bottom as illustrated.

From the last of the sheaves 48, the strand 9 now having five coats .of liquid coating composition applied thereto is directed downwardly through the oven 4|, passing down through the bottom thereof into engagement with a guide roller 55 carried by a bracket 56 whereby the down coming strand is guided over against a flange 51 of a driven sheave 58. 'I'his sheave as well as all others from a point after the strand has received its first liquid coating composition, may be provided with a surfacing material 58 in the groove of the sheave whereby the painted conduit is prevented from adhering to the sheaves. I have found that `a rubber facing admirably accomplishes this purpose. 'Ihe strand 9 is directed around the -driven sheave 58 one-and-a-half times after which it is taken off at the bottom as illustrated and directed over a discharging roller 60 which guides the completed conduit to an automatic takeup reel or other place of distribution.

Since the entire formation of the conduit is accomplished automatically, without manual assistance and continuously, it is necessary to provide the apparatus with an automatic drive which will disengage whenever the braiding machine fails to properly form the fabric covering for the flexible metallic conduit or whenever there is a cessation in the feeding of the lengths of metallic conduit. As will be obvious, due to the tortuous paths through which the strand is caused to travel to properly coat the conduit and dry the same between successive coatings to render the conduit leak-proof, the strand is subjected to considerable friction and is placed under tension. It is therefore proposed to make use of the strand itself for effecting automatic stoppage of the driven sheave 58 which pulls the strand through the entire apparatus. 'I'his is accomplished by mounting thevsheave V58 upon a lever 6| pivotally connected at one end to the supporting structure while its opposite end is free to move and has imposed thereon a sufficient weight 62 to normally retain the flange 51 of sheave 58 in frictional driving contact with a friction drive wheel 63 keyed to shaft 64 which is mounted upon the supporting structure as illustrated. Also keyed to this shaft is a dual pulley 65 having a belt 66 connected with a variable speed electric motor 61 or any other suitable source of power. A belt 68 also passes around the dual pulley 65 and is extended to rotate the take-off roll 60.

In operation, and as long as the braiding machine continues its operation, the driven sheave wheel 58 and associated parts are heavy enough to overcome the friction created on the strand in its passage through the various adjuncts and over the many sheave wheels to permit frictional engagement by gravity of the sheave 58 with the drive wheel 63 so that the former, due to the strand passing one-and-a-half times about the same is capable of pulling the strand over the various sheave wheels and .through the entire apparatus. However, should the braiding machine cease operation from one of the causes hereinbefore recited, the strand 9 will be prevented from being pulled through the apparatus due to friction plus the restraining effect on the movement of the strand 9 by the sum total of the strings or threads 6, or the failure of feeding effect of the sheave 8 or I8 in the event of either being used to assist in feeding the strand through the apparatus, thereby resulting in the strand 9 or rather its fabric coupling 23 being tensioned sufficiently so that the sheave 58 will climb up the same and automatically become disengaged from the drive wheel 63 thereby throwing the entire apparatus out of operation until the braiding machine is again started.

Due to the pulling action on the fabric covering of the strand as it is pulled through the apparatus, uncoiling of the convolutions of metallic coiled wire forming the conduit is prevented by the fabric covering distributing the pulling force or tension uniformly over the entire lengths of coiled wire sections. This slightly tensions the coiled wire so that whenV the strand of conduit material issues from the apparatus the tension thereon is relieved, the coiled wire core convolutions slightly contract, and since the coatings never become inflexible, this slight contracting becomes advantageous from the standpoint of preventing cracking of the coating and fabric when the conduits are placed in use and flexed.

In cases where higher production is demanded, this apparatus can be duplicated side by side with the power shaft 64 being extended entirely across the structural frame work to simultaneously drive any number of driven sheaves 58 found necessary to anticipate the desired production.

Having thus described the invention it will be understood that various changes in the size, shape and arrangement of parts may be resorted Ytowithout'departing'fromthe spirit of me in- ,ventionor the scope of the appended claims. J

-I claim: A

..1. In an apparatusfor; covering rmetallic-con- Vduits without manual handlinggmeans for enveloping a fabric covering over a plurality of separate conduits of spirally coiled wire to form one continuous strand, means forpulling on the enveloping fabric covering to miove the strand through the apparatus and uniformly distribute stress over the entire length of the coiled metallic V'Wire so 'as not to excessively uncoil the coiled Vvmetallic wire, an oven, a receptacle for liquid coating composition arrangedvbetween said rst named means and oven through which the stand Y is passed prior to entering said oven, and a second oven spaced from the rst whereby said strand is subjected to atmospheric drying prior to entering the second oven.

f2; In an apparatus for covering metallic conduits without manual handling, means for enveloping a fabric covering over a plurality of separate conduits of spirally coiled metallic wire to form a continuous strand, means for pulling Yon the enveloping fabric coveringV to move the strand through the apparatus and-uniformly dis'- vtribute stress over the entire length Vof the coiled metallic wire so as not to excessivelyuncoil the coiled metallic wire, an open, a receptacle for `liquid coating composition arranged between said duits without manual handling, means for enveloping a fabric covering over a plurality of separate conduits of spirally coiled metallic wire to form a continuous strand, means for Vpulling on the enveloping fabric covering to move the strand through the apparatus and uniformly distribute stress over the entire length of the coiled metallic wire so as not to excessively uncoil the coiled metallic wire, an oven, a receptacle for liquid coating composition arranged between said first named means and said oven throughrwhich the strand is passed prior to entering said oven, a second oven spaced from the first whereby said strand is subjected to atmospheric drying prior to entering the second oven, saidsecond oven having a compartment therein heated to a higher degree than the oven, and a by-pass for heat from the rst oven into the compartment of the second oven.

' 4. In an apparatus for covering metallic conduits without manual handling, means for enveloping a fabric covering over a plurality of separate conduits of spirally woundV metallic wire to form a continuous strand, means for Vpull- A ing on the enveloping fabric covering to move the strand through the apparatus and uniformlil distribute stress over the entire length of the coiled metallic wire so as not to excessively uncoil the coiled metallic wire, an oven, a receptacle for yliquid coating composition arranged between said `first named means and said oven through which 'Y position through one of Ywhich the strand passes each time it enters said second oven.

rv5. In an apparatus for covering metallic conduits without manual handling, means for enveloping a fab-ricV covering over a plurality of separate conduits of spirally wound metallic wire to form a continuous strand, means for pulling on the enveloping fabric covering to move the strand through the apparatus and uniformly distribute stress over the entire length of the coiled metallic Y wire so as not to excessively uncoil the coiled me- Vtallic wire, an oven, a receptacle for liquid coating composition arranged between said first named means and said oven through which the strand is passed prior to entering said oven, a second oven, and a second receptacle for liquid coating composition through which-the strand passes' prior to entering said second oven.

6. In combination, means for enveloping a fab- Y Vthrough said treating means,` drive means frictionally engaging said mechanism for operating the same, and said mechanism becoming disengaged from the drive means upon tension being increased on the fabric covering by said first mentioned means. 7 In combination with an apparatus for treating continuous strands of material including means for enveloping a fabric covering over a plurality of longitudinally separated sections of spirally coiled metallic wire to form the same into a continuous strand, said means having operating means for stopping the same, guide mechanism imparting tensionito the fabric covering, driven -mechanism supported by the strand for moving the same through the guide mechanism, drive mechanism'engaging the driven mechanism'for driving the same, and said driven mechanismybeing'movable along the strand to become automatically disengaged' from th-e drive mechanism when tension on the strand exceeds a `predetermined amount caused by stopping of said first mentioned means.

' 8. In combination with an apparatus for treat- Ylo ing a continuous strand of material including means for enveloping a fabric covering over a 9. In a'braiding machine having means forV braiding a fabric tube, means for guiding 'longitudinally separated sections of metallic conduits formed from sections of spirally coiled metallic wire into said machine so that the fabric tube is braided about the Vcoiled lconduit sections to form a continuous strand, a receptacle containingra liquid coating composition through which said strand is passedfrom the braiding machine, a Wall of said receptacle having an opening thro-ugh which the strand is moved, a member associated with said opening and having movement in all directions in a plane parallel to said wall, and packing material associatedV with said member having an vopening through which the strand is passed to remove surplus coating material Without scarring the strand.

10. In a braiding machine having means for braiding a fabric tube, means for guiding longitudinally separated sections of metallic conduits formed from sections of spirally coiled metallic wire into said machine so that the fabric tube is braided about the conduit sections to form a continuous strand, a receptacle containing a liquid coating composition through which said Astrand is passed from the braiding machine, a

wall of said receptacle having an opening through which the strand is moved, said wall having a circular recess concentric with said opening, a circular hub loosely seated in said recess to have movement in all directions in a plane parallel to said wall, a retaining ring overlapping the edges of said hub, and a flexible packing mounted in said hub and having an opening through which the strand is passed to remove surplus coating without scarring the strand.

11. A braiding machine having operating means for stopping the same, said machine having means for braiding a fabric tube, a guide tube for guiding sections of metallic tubing into said fabric tube as it is being formed, said guide tube having an opening, control means operatively connected to said operating means and extending into said opening tc be engaged by said sections of tubing as they pass through to maintain the o-perationof the braiding machine, and said control means automatically actuating the operating means to stop the braiding machine upon movement into said guide tube.

12. The method of covering sectional spirally coiled metallic strand material Without subjecting the same to severe uncoiling stress, consisting of feeding a plurality of longitudinally separated sections of coiled metallic material to a fabric covering device to cover and unite said separate sections into a continuous strand with only the fabric covering forming couplings between the sections, and drawing the strand through a treating appliance whereby the greater tension is exerted upon the fabric couplings to slightly uniformlystress the convolutions of coiled metallic material covered with the fabric.

13. The method of covering sectional spirally coiled metallic strand material without subjecting the same to severe uncoiling stress, consisting of feeding a plurality of said longitudinally separated sections of spirally wound metallic tubing to a fabric covering device to cover and unite said separate sections into a continuous strand with onlythe fabric forming couplings between the sections, and drawing the strand through a treating appliance whereby the greater tension is exerted upon the fabric covering to slightly uni-V formly stress the convolutions of metallic tubing.

14. In an apparatus for covering a spirally wound metallic conduit, means for applying a fabric covering to said conduit to snugly embrace the same, treating means, and means for pulling the fabric covered conduit through the treating means by exerting a pull principally on the fabricI whereby the stress on the covered conduit is uniformly distributed to the spirally wound metallic conduit by the fabric covering.

15. In combination with an apparatus for treating a continuous strand without manual handling, means for enveloping a fabric covering about a plurality of longitudinally separated conduit sections of spirally wound metallic. wire to form the same into a continuous strand, means for feeding the strand, means frictionally engaging the strand for pulling it through the apparatus with the assistance of the feeding means, drive means for operating the pulling means, and said pulling means becoming disengaged from the drive means upon increased tension being placed upon the strand when said strand enveloping means becomes inoperative.

16. In combination with an apparatus for treating continuous strands of material, means for enveloping a fabric covering about a plurality of longitudinally separated conduit sections of spirally wound metallic wire to form the same into one continuous strand, guide means imparting tension tothe strand, mechanism frictionally engaging the strand for moving it through the guide means, drive means frictionally engaging said mechanism for operating the same, and

means for disconnecting the drive means from engagement with said mechanism when tension on the strand exceeds a predetermined amount when said strand enveloping means becomes inoperative.

EDWARD D. LOWRIE.

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