US2261775A - Apparatus for making insulating tape - Google Patents

Description

Nov. 4, 1941. c, MoslER ETAL 2,261,775-

APPARATUS FOR MAKING INSULATING TAPE Filed April 4, 1938 3 Sheets-Sheet 2 efon L. Makula, j.

Nov. 4, 1941. c. MoslER ETAL f APPARATUS FOR MAKING INSULATING' TAPE Filed April 4, 1938 3 Sheets-Sheet'l 'www m@ frwezaols Cczrl Wazf J. Q l a. J JM y Nov. 4, 1941. c. Mosll-:R ETAL APPARATUS FOR MAKING INSULATING TAPE 3 Sheets-Sheet 5 Filed April 4, 1938 Patented Nov. 4, 1941 APPARATUS FOR MAKING INSULATING v TAPE Carl Mosier and John L. Mohun, Jr., Chicago, Ill.,

assignors to Union Asbestos & Rubber Company, a corporation of Illinois Application April 4, 1938, Serial No. 199,752

5 Claims.

The present invention relates to apparatus for making insulating tape, and is particularly concerned with insulating tape of the type having a woven sheath and an insulating ller.

The present application is a continuation in part of our prior application, Serial Number 108,170, filed October 29, 1936, for insulating tape and methods of making the same.

One of the objects of the invention is the provision of an improved insulating tape, which includes a structure that is adapted tov entrap air between the tape and the pipe in dead air spaces, to increase the insulating value of the tape.

Another object of the invention is the provision of an improved filler structure which is adapted to be drawn into an insulating tape sheath with greater facility by virtue of its improved structure, which gives it greater tensile strength, and which tends to cause the ller to contract into a smaller space while the filler is being drawn into the sheath.

Another object of the invention is the provision of an improved machine whereby the insulating filler is adapted to be placed within a previously constructed woven sheath.

Another is the provision of an improved machine for use in making insulating tape which is adapted to draw the insulating filler into the tape in such manner as to insure the construction of a relatively flat continuous insulating tape of uniform insulating characteristics.

Other objects and advantages of the invention will be apparent from the following description and the accompanying drawings, in which similar characters of reference indicate similar parts I construction with the filler and sheath as they appear 'at theI beginning of the operation of drawing the filler into the sheath.

Fig. 3 is a diagrammatic fragmentary plan view of a portion of an insulatingf'lller constructed according to the present invention.

Fig. 4. is a fragmentary plan view of a pOrtion ofthe insulating sheath constructed according to present invention:

Fig. 5Y is a fragmentary view in perspective of an insulating tape constructed according to presbe adjacent to the article to be insulated uppermost.

Fig. 6 is an enlarged diagrammatic plan view of the upper side of the insulating sheath of Fig. 5 showing the details of its construction.

Referring to Fig- 5, the presentinsulating tape, which is indicated in itsv entirety by the numeral I0, preferably comprises a woven insulating sheath II, which is tubular in shape, and which is provided with an insulating filler, indicated in its entirety bythe numeral I2.

The ller preferably consists of a plurality of large, loose and soft rovingsof asbestos fibers, the rovings being indicated by the numerals I3,

I4, I5, It and I 'I.

These rovings may be made of relatively long fibers or short fibers, and in some cases other insulating fibers, such as vegetable or animal fibers, may be used. In the preferred embodiment of the inventionv the rovings have very little or practically no tensile strength, although a slight amount of vegetable fibers may be included to increase the tensile strength of the rovings to facilitate handling of the rovings during the manufacture 0f the filler l2.

These rovings are preferably so arranged that they overlap each other; that is, the rovings I6 and I1 arc disposed over the crack between the rovings I2 and I3 and I4 and I5 respectively. When the filler is complete, the rovings atten out to an elongated structure, which may be substantially rectangular vin cross section.

The filler I2 also preferably includes at each edge an asbestos rope I8, I9, which comprises asbestos or other fibers 'tightly twisted together,

for the purpose of giving the ller a greater tensile strength.

Referring to Fig. 3, the rovings I3 to I'I may be secured together by aplurality of threads 20, 2I and others extending spirally' around the assembly I2--Il in a left handdirection as viewed in Fig. 9, and by a plurality of other threads 22, 23, and others which extend spirally around the assembly l3-I9 in the opposite or right hand direction. These spiral threads 2li-'J3 and othersform a basket weave about the rovings and ropes and hold the parts of the filler together. When the spirally extending threads 2li-23 are subkjected to longitudinal tension with the rest of the ller, they tend to cause the filler to contract into a smaller space so that it can be more readily -:inserted in its sheath.

The ropes t8, I9, give the filler atensile strengthwhich enables it to be drawn into the ent invention, that side of the tape which ist@ sheath II in substantial lengths, such as, for exf ample, fifty feet, more or less. In addition to the threads 2li-23, other longitudinally extending threads 24, may be arranged at the edges of the rovings to increase the tensile strength of the assembly. It -shouldbe understood that any number of rovings may be used, and rovings are preferably used in the preferred form of the invention. In some embodiments of the invention, however, other forms of flat fillers of less insulating value might be used with the improved sheath.

Referring to Fig. 5, this shows the outside of an pressions 28 are adapted to entrap air between the sheath and the. pipe when the sheath is spirally wound on a pipe or when it is applied to any other surface. This greatly increases the insulating value of the sheath and causes this increase at a slight additional cost, which is not proportionate to the increased value of the tape.

The structure of Fig. 5 may be accomplished in different ways, one example being the addition to the sheath of longitudinally and transversely extending relatively large threads or ropes of asbestos.

In the embodiment of Fig. 1, however, additional longitudinally extending large threads or ropes 29 have been used, located on the lower outside of the sheath and equally spaced from each other. Referring to Fig. 4 and Fig. 6, in this embodiment 30 indicates the weft threads and 3| the warp threads. Every fourth weft thread extends over the large thread or rope 29 and binds it to the woven assembly. Thus, for example, the large thread or rope 29 in Fig. 4 is secured by the weft thread 30 at the bottom, the woven thread 30 at the middle of the gure, and left thread 30 at the top.

The weft threads 30 may be drawn so tightly in the weaving that they cause the portions 21 of the Warp threads 3| to project outward above the rest of the surface of the weave. In other words, the thread portions 21 project outward substantially'as much as the ropes 29. This gives the appearance of the sheath onthat side a waffle-like formation, as shown in Fig. 5, the transverse ridges being formed by the outwardly projecting portions 21 of the warp threads 3|.

' and 2|, and they are secured by engagement with the weft threads 30.

Referring to Figs. l and 2, these are diagrammatic illustrations of a part of the 'apparatus used in the manufacture of the insulating tape previously described. In Fig. 1, 50 indicates a table top which may be slightly longer than the longest length of sheath which is intended to be lled by one operation of drawing the filler into the tape; for example, if the tape is to be made in fifty-foot lengths, the table may be 55 or 60 feet that -may compriseanangle iron member 52,

provided with a relatively flat tubular member 53.

. The horizontal flange of the iron 52 is secured to the table 50 by a plurality of screws, bolts, or other-fastening means, and the vertical ange of the iron 52 carries the flat or oval tubular member 53.

The tubular member 53 is constructed of metal and it is of sufficient size, with respect to the sheath Il, so that the sheath Il is rather tightly stretched when it is placed upon the tubular member 53, as shown in Fig. 1.

In order to insure the securement of the sheath I on the tubular member 53, the apparatus may be provided with a cord having a loop, 54, embracing the sheath and tubular member 53, and drawn tight by means of a slip knot 55, the end. of the cord being tied to a peg 56 'in the table 50.

The shape of the .tubular member 53 end elevation approximates the shape of a flat tubular sheath I I, with which it is used. The tubular member 53 is adapted to serve as a rigid and xed eye for the end opening of the woven sheath II and also for securing the sheath II in place, while the -ller I2 is drawn into the sheath.

The filler I2 may be'as shown in Fig. 3 and may be provided in suitable lengths to correspond to the length of the sheath and is stored in coils in a suitable barrel 51. y A

It should'be understood that the table 50 may be provided with any number of different apparatus, including the fixture 5| andthe machinery for drawing ller into a multiplicity of sheaths at the same time.

The apparatus for drawingthe filler into the sheath is mounted at the right handend of the table in Fig. 1, and it comprises a suitableelectric motor, 58, provided with worm gear for driving `the gear wheel 59, which is mounted upon a horizontal shaft, 60. The shaft 60 is rotatably mounted in bearings carried by the brackets 6I, and it is provided withone or more drums, 62, which may be located between the vertical guides 63, 64.

Each drum 62 has secured toits periphery a tension member 65, which may consist of a length of flexible steel strap. The strap 65 of spring steel is longer than the length of the table 50 so that it may extend, when unwrapped from the drum, to a point beyond the fixture 5I, where it may be secured to the filler I2. At its free end, the steel strap is provided with a U shaped metal member 66, secured thereto by rivets or other fastening means and having a. loop for receiving a cord 61. The cord 61 may have a slip knot formed in its opposite en'd and maybe looped around the end of the ller I2 at 68.

In order to insure the wrapping of the strap 65 upon the relatively narrow drum 62, additional guide members 69 and 10 are provided on each side of the drum 62 for slidably engaging the edges of the strap 65 and confining it to the drum 62. Any number of drums in 62 may be employed upon the same shaft 60, depending upon the size of the motor, the length of the sheath into :which the filler is to be drawn, and the resistance encountered.

We have found it convenient to use a pair of drums on the same shaft and same table, but it Is not necessary to use both drums at the same time. The sheath is secured to the tubular member 53 at one end and is laid out on the table 50 in approximately a straight line and extending toward the drum 62. Each drum 62 is preferably loosely mounted on the shaft 60 and its connection to the shaft 60 is controlled by a clutch 1I, the clutch being actuated by a lever 12. The operation of the machine will be apparent from the foregoing description.

'Ihe spring steel strap 65 is sufficiently stili so that it can be threaded or inserted into the sheath I I, beginning at the right hand end 13. The naturl shape of the strap is straight so that it will lie flatly on the table and so that it can be pushed into the Isheath I I until it emerges from the tubu` f lar member 53. l

The operator may then grasp the cord B1 and place the loop 68 about the end of the filler I2. The loop 68 should not only embrace the rovings I3--I8, but it should also embrace the ropes I8, I9 and embrace threads 2I-23'of the ller. The loop 68 should also bearranged as close to the end of the filler as it can, while also making a secure connection between the cord (i1v and the ller I2.

Wei-ind that one good Way to accomplish' this result is t double over the end of the filler and arrange the loopI, embracing the double portion ofA the filler. The head I4 of the filler is thus formed by a doubled or bent over portion, which is less apt to be disintegrated during its passage through the sheath I I.

that it does not form an obstruction to the drawing of the ller I2 into the sheath I I.

The motor 58 may then be started and the drum B2 will wind up the lstrap 65 and draw the filler I2 into the sheath'II, until it emerges at the end 13. Thereafter the excess portions of filler I2 are cut off and the sheath is detached from the tubular member 53. The ller is, of course, detached from the strap 65. Care must be taken during the drawing in of 'the filler to see that it lies flat and does not become twisted and the sheath II must, of course, be laid out flat without any twists.

The nature ofthe basket weave of the enclosing -threads 2 I-23 is such that a tension on these threads tends to cause the ller to contract, whereby it may be more easily drawn into the sheath. I

Our method of the manufacture of insulating tape may be outlined briefly as follows:

The woven sheath is constructed als a unit and woven by a weaving machine into tubular. form, the threads being composed mainly of asbestos. In many cases a small percentage of cotton may be interwoven with the asbestos for the purpose of increasing its tensile `strength, and if desired, ne metal wires may also be included.

'Ihe ller I2 may be assembled as shown in Fig. 3 Aand embracing threads 2I-23, may be wrapped spirally in both directions about the filler and the edge ropes I8 and I9. The filler is coiled in a barrel or other container 51, so that it may be freely withdrawn from the container when it is to be assembled with the sheath.

The sheath is cut into predetermined lengths and laid out at upon the table, one end ofthe sheath being secured -to a tubular member. A relatively stilf tension member is threaded through the sheath from the opposite end until it emerges at the tubular member, whereupon the tension member is secured to one end of the filler; thereafter, the ller is drawn into the sheath by means of the tension member, the act of drawing this member, causing the embracing threads on the filler to contract the filler into a smaller space for The slip knot of the cord 61 is adapted t0 Compress this doubled head so applied by means'of rollers, the lowermost of4 facilitating its entry into the sheath; The filler is carefully guided and fed into the tubular mem' ber and sheath 'without twisting, so that itwill.v

lie flat within the sheath'.

The excess of filler atv each end of the-sheath is then cut olf and the insulating tape is then adapted to be used by being wrapped spir'aily about a pipe or other object.

In certain'embodiments of the invention the sheath will be provided with a dead airspace 28 on Fig. 5, by means of the longitudinally and transversely extendingridges 26 and 21 which are formed in the opera-tion of the` weaving of the sheath. y The side of the sheath,

vided with a waterproof covering which may be which dips into a container. of waterproong and impregnating compound, such as a compound including a rubber latex and an evaporating sol- Vent. The waterproof compound preferably extends to the ends of the sheath and over the rear side of the sheath, that is, toward the uppermost-side in Fig. 5, so' that the article `which is waterproofed coversenough of the. tape so that the waterproofed edges may engagey eachother when the tape is spirally wrapped upon a pipe.

It will th'us be observed Vthat we have invented an improved machine for use in the manufacture of insulating tape and improved methods of manufacture of insulating tape by. means of which the tapemay becovered with a properly woven asbestosk sheath. It is not necessary to turn the sheath inside out to ll it according'. to the present methods, nor is it necessary to stitch the edges of the sheath together after the ller has been placed in it, and the insulating tape is constructed with the present apparatus according to the present methods of substantially vuniform heat insulating characteristics and may be manufactured more cheaply than the insulation of the prior art, having equivalent insulating value. i

While we have illustrated a preferred embodiment of our nvention, many modifications may be Amade without departing from the spirit `of the invention, and we do not wish to be limited to the precise details of construction set forth,

but desire to avail ourselves of all changes within the scope of the appended claims.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent of the United states, is:

1..An apparatus for makinginsulating tape, Vcomprising an elongated support for supporting a length of sheath in extended position, a tubular member carried by one end of said support, having vits axis extending in the direction of the sheath on said support, means for securing one end of the sheath about said tubular member, a winding drum carried by the opposite end of said support, said winding drum being mounted on a shaft and having means for rotating said drum, and a relatively stiff, yet windable member, secured to s aid drum and adapted to be wound thereon, said stiff and windable member being normally substantially straight and insertable in said sheath when extended on vsaid support, whereby said latter member may be inserted through the sheath and through said tubular member and secured to a ller to draw the filler into the sheath.

2. An apparatus for making insulating tape, comprising an elongated support for supporting a length of sheath in extended position, a tubuor the side opposite to i the dead air spaces, I8, is also preferably prolar member carried by one end of said support,

. having its axis extending in the direction of the support, said winding drum being mounted on a shaft' and having means for rotating said drum, and av relatively stiff yet windable member secured to said drum and adapted to be Wound thereon, said stiff and windable member being normally substantially straight yand insertable in said ysheath when extended on saidA support, whereby said latter member may be inserted through the sheath and through said tubular member and secured to a ller to draw the filler into the sheath, said driving means comprising an electric motor and clutch means interposed between said motor, and saiddrum, to permit unwinding of said stii. and windable member.

3. An apparatus for making insulating tare,

4comprising an elongated support for supporting a length of sheath in extended position, a tubular member carried by one end of said support, having its axis extending in the direction of the sheath on said support, means for securing one end of'thesheath about said tubular member,

a winding drum carried by the opposite end of said support, said winding drum being mounted on a shaft and having means for rotating saiddrum, and a relatively stift yet windable member secured to said drum and adapted to be wound thereon, said stiff and windable member being normally substantially straight and insertable in said sheath when extended on said support, whereby said latter -member may be inserted through the sheath and through said tubular member and secured to a iiller to draw the filler into the sheath, said stii and windable member comprising a steel tape.

4. In an apparatus for filling the sheath of an insulating tape, the combination of a supporting table with a winding mechanism mounted on one end of said table, said mechanism comprising a motor drive, speed reducing gearing and a drum shlaft, a plurality of drums on said shaft, a. clutch interposed between each of said drums and said drive shaft, and a steel tape wound upon said drum, said steel tape being normally straight and relatively stii, althoughI Vsuiiciently exible to be wound on the drum, and means for securing one end of a wovenA sheath to the other end of the table, with the sheath in extended position, substantially in alignment with said tape, when extended, and means for securing a filler to the end of said steel tape after .it has been threaded through a sheath on said table.

45. An apparatus Afor lling insulating tape. comprising a supporting table, a bracket carried by said table adjacent one lend thereof, said bracket having a tubular supporting member fixedly secured thereto for supporting one end oi a tubular sheath, a tension member adapted to be looped about the sheath to bind it tothe tubular member, and means for securing said tension member to the table, a drawing mechanism at the opposite end of said table, including a drum and a normallystraight resilient metallic ribbon carried by said drum, said ribbon having one end secured to the drum and having a tension member provided with a slit loop carried by the other end of said ribbon for securement to a illler for said sheath, an electric motor and speed reducing gearing for driving said drum, and clutch means interposed between said drum and said motor whereby the metallic ribbon may be ,threaded through the sheath while the sheath is supported by said tubular member and extended in a straight line on said table and the metallic .ribbon may be secured to a ller so that the iiller may be drawn into said sheath by means of said motor and drum.

CARL MosIER. JOHN L. MOHUN, Jn.

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