US3635413A

US3635413A - Break detection and correction system for threadlike materials

Info

Publication number: US3635413A
Application number: US888434A
Authority: US
Inventors: Davis S Gish
Original assignee: Hercules LLC
Current assignee: Hercules LLC
Priority date: 1969-12-29
Filing date: 1969-12-29
Publication date: 1972-01-18
Anticipated expiration: 1989-01-18

Abstract

A device for detecting the breakage of a filament as a filament passes to a working surface is provided. The detection device has a conduit through which a filament and a gas passes. This conduit is connected through a pressure port to a device for measuring pressure change. If a filament being pulled from a supply source through the conduit of the device is broken, the filament will be pulled out of the conduit. When the broken filament is pulled out of the conduit a change in pressure occurs in the pressure port. The change in pressure is sensed by the device for measuring pressure change and a filament breakage alarm is activated. A break detector and correction system is also provided in which a broken filament is replaced. In this system the change in pressure at the pressure port activates a filament-replacing system.

Description

United States Patent [151 3,635,41 3 Gish [451 Jan. 18, 1972 [54] BREAK DETECTION AND 2,988,294 6/1961 Neff ..242/75.52 X CORRECTION SYSTEM FOR 3,088,175 5/1963 Aoki ..19/240 THREADLIKE MATERIALS 3,462,936 8/1969 Boucek et al ..57/80 [72] Inventor: Davis S. Gish, Bel Air, Cumberland, Md. Primary Examiner-George F. Mautz [73] Assignee: Hercules, Incorporated, Wilmington, Del. AtwmeyMlchael Keehan [22] Filed: Dec. 29, 1969 [57] ABSTRACT [21 Appl. No.: 888,434 A device for detecting the breakage of a filament as a filament passes to a working surface is provided. The detection device has a conduit through which a filament and a gas passes. This [52] Cl conduit is connected through a pressure port to a device for [51] Int Cl 865', 65/02 B65h 25/08 measuring pressure change. if a filament being pulled from a [58] Field 542 54 57 38 75 upply source through the conduit of the device is broken, the 57/80 f d filament will be pulled out of the conduit. When the broken 1 ,5 240 4 d filament is pulled out of the conduit a change in pressure occurs in the pressure port. The change in pressure is sensed by the device for measuring pressure change and a filament [56] References Cited breakage alarm is activated. A break detector and correction UNITED STATES PATENTS system is also provided in which a broken filament is replaced.

In this system the change in pressure at the pressure port acyalnwrrght 19/240 UX tivates a fil t l i system. ewrs et a 2,909,275 10/1959 Hitchcock ..242/75.53 X 11 Claims, 10 Drawing Figures PATENTEU JAN I 8 I972 SHEET 1 [IF 3 FIG.2

FIG.|

FIGS

DAVID S. GISH INVENTOR FIG.5

BY WM 1640 ATTORNEY PATENTEU JAN 1 8 m2 sum 2 or 3 FIG. IO

DAVID S. GISH I N VENTOR ATTORNEY Pmimeuumrwrz 3635413 SHEET 3 [1F 3 DAVID S. GISH INVENTOR ATTORNEY BREAK DETECTION AND CORRECTION SYSTEM FOR THREADLIKE MATERIALS This invention relates to a device for detection of filament breakage in the manufacture of tape and broad goods. In another aspect this invention relates to a break detection and correction system for automatically determining filament breakage in the preparation of a multifilament tape or broad goods and automatically replacing the broken filament.

It is oftentimes desirable when preparing self-supporting articles from high-strength filaments by techniques such as filament winding to employ tapes or broad goods comprised of a plurality of high-strength filaments bonded together, rather than to manufacture the article from single filaments. Tapes or broad goods, as these terms are used herein, are sheet products prepared from a plurality of high tensile strength filaments laid down in parallel relationship in contact with a suitable binding material. The tape or broad goods thus produced are particularly suitable for manufacture of self-supporting articles by filament winding methods.

In the manufacture of tape and broad goods filament breakage is a serious problem. If filament breakage occurs during preparation of the tape or broad goods, the tape or broad goods produced will have gaps or discontinuities within it which adversely affect strength. Large quann'ties of defective tapes and broad goods produced as a result of filament breakage cause considerable loss in valuable product and production time.

Accordingly, it is an object of this invention to provide an apparatus for detection of filament breakage in a filament processing system.

It is another object of thisinvention to provide a filament break detection and correction system for use in manufacture of tapes and broad goods which will automatically detect a broken filament and replace the broken filament.

It is still anotherobject of this invention to provide an apparatus for detection of filament breakage which also functions as a collimator for filaments causing the filaments to arrive at a work'surface in proper spaced relationship.

Other objects of this invention will, in part, be obvious and will, in part, appear hereinafter. For a complete understanding of the nature and objects of this invention reference is made to the following detailed description.

In accordance with this invention there is provided a filament break detector havingin combination (a) a filament sensor body having a conduit therethrough said conduit being of a size sufficient to allow a filament to pass endwise through said conduit and to allow gas to pass about the filament through said conduit, and a port communicatively connecting said conduit to the exterior surface of the sensor body and (b) a means communicatively connected to the port of the sensor body responsive to changes in pressure in the port of said sensor body, as a result of a filament breaking for indicating filament breakage.

Further, in accordance with this invention a filament break detector and correction system is provided for an apparatus for manufacture of tape or broad goods or other filament derived products in which filament is passed through a filament sensor to a working surface, said system comprising (a) a filament sensor body having a conduit therethrough said conduit being of a size sufficient to allow passage of a filament and a gas through the conduit and a port communicating said conduit to the exterior surface of the sensor body, (b) a filament supply means for providing filament for delivery through the conduit in the sensor body, means for advancing filament from the filament supply means through the conduit in the sensor body to a pull means, (d) a gas supply means providing gas flow through the conduit in the sensor body, and (e) means communicatively connected to the port of the sensor body responsive to changes in pressure in said port resulting from a broken filament being pulled past said port, for actuating the means for advancing filament from the filament supply means through the conduit in the sensor body to the pull means.

The following. drawings more fully illustrate this invention. In the drawings like symbols are used for like parts where applicable.

FIG. lis a'front view of a filament'break detector of thisinvention.

FIG. '2 is aside view of the filament break detector of FIG. I, partly broken away and 'partlyrin section.

FIG. 3 is a cross section along line 33 of FIG. 2.

FIG. 4 is a partial end view of'the break detector of FIG. 1.

FIG. Sis an elevation of another embodiment of a filament break detector of this invention.

FIG. 6is a side viewof the filament'break detector of FIG. 5, partly broken away and'partlyin'section.

FIG. 7 is a schematic drawing of-anenibodiment of the'filament break detector system of'this invention.

FIG. 8 is a schematic drawing ofan embodiment of the filamentbreak detector and correction system of this invention.

FIG. 9.is a schematic drawing of another embodiment of the filament "break detector and correction system-of this invention.

FIG. 10 is afront view partly broken away and partly in section illustrating a filament supply magazine employed in this invention.

In FIG. 1 a sensor body of the filament break detector of this invention is shown prepared-in two sections, a top section 10 and a bottom section 12. The assembled sensor body has a cavity 14 therethrough. A plurality of filament tubes (conduits) 16 each having an input-end and an output-end are positioned in two rows,-a top row 18 and a bottom row 20, in side-by-side relationship in the sensor body cavity 14. The size of the sensor body cavity 14 and the number of tubes 16 in the cavity 14 are determined so that precise control of the relative positions of each tube 16 in the sensor body cavity 14 can be maintained. In this way the sensor also acts as a collimator for the filaments. The inside diameter of each filament tube is sufficient to allow passage of a filament and gas therethrough. The tubes in the top row 18 and bottom row 20 are staggered relative to each other so that filaments (not shown) passing to a working surface through saidtubes are in uniformly spaced relationship when they contact the working-surface. The space 22 remaining between tubes 16 and between the tubes 16 and the sensor body cavity walls 24 is filled with a curable resin to hold the tubes finnly within the cavity I4. A plurality of pressure ports corresponding to the number of filament tubes and as illustrated by

pressure ports

26, 28, 30 and 32 communicatively connect each filament tube 16 to the exterior surface of the sensor body.

In FIG. 2 a side view of the filament break sensor body of FIG. 1 is shown illustrating the relative position of the filament tubes 16 having an input-end 34 and an output-end 36 and

pressure ports

26, 28, 30 and 32within the sensor body. The scale of the drawings shown in FIGS. 1 and 2 is about l2.5/l. Thus, due to the small size of the sensor body, the desirability of staggering the filament tubes 16 and employing

pressure ports

26, 28, 30 and 32 passing through both the top section 10 and bottom section 12 of the sensor body is apparent considering the space available. A filament 38 is illustrated passing endwise through filament tube 16. Filament 38 partially blocks the intersection 40 of pressure port 28 and filament tube 16. The outside diameter of the filament 38 approaches the inside diameter of the tube 16 but the filament 38 can readily pass through the filament tube 16 and still provide space for a gas to pass around-the filament 38. In this embodiment of this invention gas enters the filament sensor through the filament tube 16. FIG. 3 is illustrative of the relative diameters of filament 38 and the inside diameter 41 of filament tube 16 and also of the gas space 42 about filament In FIG. 4 the spacing of conduits in the filament sensor body of this invention is illustrated for a prepared application of this invention of making tapes or broad goods. In this arrangement a line 43 drawn through the center of each conduit perpendicular to the longitudinal'axis of each

conduit row

44, 45 is tangent to the outside diameter of the adjacent conduit(s) 46 in the opposite tube row.

In FIGS. 5 and 6 a second embodiment of the filament break detector of this invention is illustrated. The filament break detector is comprised of a sensor body having a top section 47, a bottom section 48, a cavity 50, a plurality of filament tubes 52 in two rows in side-by-side relationship and a pressure port 54, for each filament tube (shown by illustration of port 54 only). Each pressure port 54 communicatively connects a filament tube 52 to at least the exterior surface 56 of the sensor body. In this embodiment, gas providing pressure for operation of the detector system passes through a gas supply port 58 and flows through filament tube 52 and past pressure port 54. This gas exhausts at the output-end 60 of the filament tube 52. The gas supply port 58 intersects filament tube 52 at an acute angle so that there is a continuous flow of gas in the filament tube 52 toward the output-end 60 thereof.

OPERATION OF THE FILAMENT BREAK DETECTOR AND CORRECTION SYSTEM FIGS. 7, 8 and 9 illustrate various systems for employing the filament break detector system of this invention. In describing this operation, reference is made to only one filament and conduit, it being understood that operation of the device is the same regardless of the number of filaments and conduits employed.

In FIG. 7 a simple break detector system is shown comprised of a filament supply magazine 62, a filament break sensor 64, a pneumatic logic amplifier 66, a pneumatically actuated filament breakage alarm 68, an air supply 70, pull rolls 72 and a takeup reel 74 having a working surface 75 and operated by motor 76. A filament 77 supplied from filament supply magazine 62 passes through conduit 78 and into a filament tube 80 in the filament break sensor 64. Filament 77 passes through the pull rolls 72 onto a sheet of resin paper 82 and then to working surface 75. The resin paper 82 contains a resin coated side on which the filament(s) 77 lie and are bonded together thereon, and a noncoated side. The filament supply magazine 62 has an airtight body capable of withstanding moderate air pressure. Air from air supply 70 passes through conduit 84 into air inlet 85 in filament supply magazine 62 and through the filament outlet 86 of the filament supply magazine 62 through conduit guide means 78 and through filament tube 80 in filament break detector 64 after which it exhausts through the output-end 88 of filament tube 80. The air passing about filament 77 puts an air drag on the filament 77 which aids in drawing the filament 77 through the filament sensor 64. A pressure port 90 communicatively connects filament tube 80 to the exterior surface of the filament break sensor and a conduit 92 connects pressure port 90 to the pneumatic amplifier 66. Air from air supply 70 establishes a first reference pressure at input-1, 94, of pneumatic logic amplifier 66. Filament breakage alarm 68 is connected to the output-l, 96, of pneumatic amplifier 66. In a typical operation of the system described, filament is delivered from filament supply magazine 62 to the working surface 75. Air flowing through conduit 84, magazine 62, conduit 78 and the filament tube 80 in filament break sensor 64 establishes a pressure at pressure port 90 which is received at pressure input-2, 98, of pneumatic amplifier 66. The pneumatic amplifier 66 is calibrated for a given pressure balance across input-1, 94, and input-2, 98, and is set for a nonactive mode when the system pressure balance is within a precalibrated pressure range. If a filament should break between the break detector and the filament supply magazine the pull rolls 72 will draw the broken filament through the filament tube 80 in break detector 64 causing the pressure at pressure port 90 to change thereby establishing a pressure imbalance to occur at pneumatic amplifier 66. The pressure imbalance activates the pneumatic amplifier 66 which in turn activates the filament breakage alarm 68. This alarm 68 can be programmed to stop all equipment or give any type of signal desired to indicate filament breakage.

In FIG. 8 the preferred embodiment of the filament break detector and correction system of this invention is shown. This system is similar to the system of FIG. 7 with the exception that the output from the pneumatic amplifier 66 is connected to an air motor 100 which drives a gear 101 which in turn engages the geared surface 102 of filament supply reel 104 for imparting angular rotation thereto (see FIG. 10). In a typical operational sequence in which a filament 77 breaks, the detector and correction system functions as follows. A pressure imbalance is sensed by pneumatic amplifier 66 as the end of the broken filament 77 is pulled past pressure port 90. Pneumatic amplifier 66 is activated sending air through conduit 105 into air motor 100. Air motor 100 immediately drives the reel 104 on filament supply magazine 62 in a clockwise direction forcing filament 77 through conduit 78 and through filament tube in break sensor 64. As filament 77 passes through the intersection of pressure port and filament tube 80, balance is restored at pneumatic amplifier 66. Pneumatic amplifier 66 immediately goes into a nonactive mode and air to the air motor is immediately shut off. In the foregoing sequence the filament break detection and correction system is sufficiently responsive for most filamentary materials to permit manufacture of tapes in which substantially no gaps occur. Any gap that does occur is very small generally less than about 0.25 inch.

In FIG. 9 another embodiment of a filament break detection and correction system is shown employing a filament break sensor as illustrated in FIGS. 5 and 6.

This system is similar to the system of FIG. 7 with the exception that air from air supply 70 is fed directly through conduit 106 to an air supply port 108 in break sensor 110 and exhausts at the output-end 112 of filament tube 114 in break sensor 110. In operation of this system, filament 77 from filament supply magazine 62 passes through conduit 78 to the inputend 116 of the filament tube 114 in break sensor 110 and passes through the output-end 112 of the filament tube 114 into pull rolls 72 and then to a working surface 75. If filament 77 should break, a pressure imbalance will occur as the end of the broken filament is pulled past pressure port 118 activating pneumatic amplifier 66 whereby air is sent through conduit starting air motor 100 on the filament supply magazine 62. Air motor 100 on filament supply magazine 62 drives the reel of filament supply magazine in clockwise direction forcing filament through conduit 78 and break detector 110. As filament 77 passes through the intersection of pressure port 108 and filament tube 114, pressure balance is restored at pneumatic amplifier 66. Residual motion of the filament supply reel advancing the filament through the sensor body brings the new advancing filament into contact with the pull rolls 72.

In FIG. 10 filament supply magazine 62 is illustrated. The magazine has a top section 118, and a bottom section 120. The sections are secured together by

wing bolts

122, 124. A filament supply reel 104 is rotatable about shaft 126. Filament supply reel 104 has a geared surface 102. The air supply motor (not shown) drives gear 101 which engages gear 102 to impart angular rotation to reel 104. Filament (77) stored on reel 104 passes through filament outlet 86. Air from air supply (not shown) enters filament supply magazine 62 through air inlet 85 and exhausts through filament outlet 86. Other means of driving the filament supply reel 104 such as by fraction friction drive or by connecting an air motor directly to shaft 126 are satisfactory.

In the break detection system of this invention the pressure change occurring within the filament breakage sensor is a result of a broken'filament being drawn past the port in the sensor body and out of the sensor. Gas flows through the sensor at a constant input pressure and rate when filament is passing through the sensor. The pressure in the conduit is sensed by the pneumatic amplifier at the pressure port intersecting said conduit. When a filament breaks it is drawn through the sensor body. With the restriction provided by the filament removed, pressure within the sensor body decreases. This change in pressure is sensed by the pneumatic amplifier which operates in a sequence designed to advance filament from the filament supply magazine into the system. Pneumatic amplifiers are illustrative of means responsive to change in pressure in the pressure port of the sensor body of this invention. A particularly suitable pneumatic logic amplifier is ARO model 59176, sold by the ARO Corporation, Bryan, Ohio.

From the foregoing description it is clear that the filament passing through the conduit in the sensor body must have a large enough diameter in relation to the diameter of the conduit to restrict the flow of gas through the conduit. The ratio of the diameter of the conduit in the sensor body to the diameter of the filament passing through the conduit is important in establishing a measurable pressure change in the port of the sensor body. Thus, a measurable change in pressure must occur in the filament break detector of this invention between the condition of filament continuously passing through the detector in a steady state operation, and the condition of a filament being pulled out of the detector because of filament breakage. The ratio of the diameter of the conduit(s) in the sensor body to the filament diameter for any given system will vary depending in particular on the sensitivity of the pressure sensing means, and the surface characteristics such as the smoothness of both the conduit and the filament. In general, the ratio of the filament tube diameter to the filament diameter should be about 4/1 or less. Preferably, the ratio of filament tube diameter to the filament diameter is less than about 2/1. ln a typical filament break and detection system employing boron filaments, the outside diameter of the filament is 0.004 inches and the inside diameter of the conduit in the sensor body is 0.006 inches.

The method employed for advancing filament from the filament supply magazine through the conduit in the sensor body to the working surface will depend on the type of filament employed. When employing stiff filaments such as boron filaments, the filament can be advanced through the system by pushing the filament such as by rotating a reel of filament and guiding the unwound filament to the conduit in the sensor body and to the working surface. This method can also be employed for stiff glass filaments.

When employing filaments, which do not have the stiffness of boron filaments such, for example, as carbon filaments the filaments are advanced from the filament supply magazine to the pull rolls and working surface of the apparatus by directing a flow of gas through a conduit guide means connected to the supply magazine and to the conduit in the sensor body, said gas exhausting at pull rolls adjacent to the output-end of the filament break sensor. The gas passing through the conduit means continuously imposes a fluid drag or tension on the filament thereby urging the filament toward the working surface. With this type of system both the filament supply magazine and guide means are preferably gastight. Gas drag on the filaments is employed in combination with a means for imparting rotation to the filament supply reel so that filament is readily released from the reel for advancement through the conduit guide means.

What I claim and desire to protect by Letters Patent is:

l. A filament break detector device comprising:

a. a filament sensor body having a conduit therethrough, said conduit being of a size sufficient to allow a filament to pass endwise through said conduit and a gas to pass about the filament in the conduit, and a port communicatively connecting the conduit to the exterior surface of the sensor body,

b. means for directing a gas into and through said conduit in the direction of movement of said filament to urge said filament through said conduit and to provide a predetermined pressure in said conduit, and

c. means communicatively connected to the port of the sensor body responsive to changes in pressure in the port of the sensor body as a result of filament breaking for indicating filament breakage.

2. The filament break detector of claim 1 wherein the sensor body has a plurality of conduits, a pressure port communicatively connecting eachconduit tothe exterior surfaceof the sensor body, and a means communicatively connected to each pressure port responsive to changes in pressure in the port of the sensor body as a result of filament breaking for indicating filament breakage.

3. The filament break detector of claim 2 wherein the means responsive to changes in pressure in the port of each conduit through the sensor body for indicating filament breakage is a pneumatic logic amplifier in combination with a pneumatically actuated alarm.

4. The filament break detector of .claim 2 wherein the conduits through the sensor body are tubes arranged in one or more rows in a spaced relationship.

5. The filament break detector of claim 4 wherein the sensor body comprises a top section and a bottom section, said top section and bottom section being assembled to form the sensor body and defining a cavity through the assembled sensor body, said defined cavity holding a first row and a second row of tubes in parallel and side-by-side relationship, such that a line passing through the center of each tube and perpendicular to the longitudinal axis of each tube row is tangent to the outside diameter of the adjacent tube or tubes in the opposite row.

6. A filament break detection and correction system having in combination:

a. a filament sensor body having a conduit therethrough said conduit being of a size sufficient to allow a filament to pass endwise through said conduit and a gas to pass about the filament in the conduit and a port communicatively connecting said conduit to the exterior surface of the sensor body,

b. a filament supply means,

c. means for advancing filament from the filament supply means through the conduit in the sensor body to a pull means,

d. gas supply means for providing gas flow through the conduit in the sensor body, and

e. means communicatively connected to the port of the sensor body, responsive to changes in pressure in said port resulting from a broken filament 'being pulled past said port by said pull means, for activating the means for advancing filament from the filament supply means through the conduit in the sensor body to the pull means.

7. A filament break detection and correction system comprising:

a. a filament sensor body having a conduit therethrough said conduit being of a size sufficient to allow a filament to pass endwise through said conduit and a gas to pass about the filament in the conduit, and a port communicatively connecting said conduit to the exterior surface of the sensor body,

b. a filament supply magazine comprising a magazine body having a filamentoutlet, a supply reel, filament wound about said supply reel, and means for mounting said reel within said supply magazine to permit rotation of said reel,

c. means for imparting angular rotation to said filament supply reel whereby filament is released from said reel through the filament outlet,

d. guide means providing a passageway from the filament outlet through the conduit inthe sensor body to a pull means,

e. means for advancing filament along the guide means into the pull means,

f. gas supply means forproviding gas flow through the conduit in the sensor body, and

.g. means communicatively connected to the port of the sensor body responsive to changes in pressure in said port resulting from a broken filament being pulled past said port for actuating the means for advancing filament from the filament supply magazine through the sensor body to the pull means.

8. The filament break detector and correction system of claim 7 wherein the filament is boron filament and the means for imparting angular rotation to the filament supply reel and the means for advancing filament along the guide means comprises an air motor which drives the filament supply reel imparting angular rotation thereto whereby the boron filament from said reel is released and pushed along the guide means through the sensor body and to the pull means.

9. The filament break detection and correction system of claim 7 wherein the magazine body is gastight and has a gas inlet and a filament outlet which is also the gas outlet and said filament guide means comprises a gastight passageway connecting the magazine body to the inlet of the conduit of the filament sensor body, the gas supply means being connected to the gas inlet of the filament supply magazine body providing gas flow through the filament and gas outlet of the magazine body through the filament guide means and conduit in the filament sensor body.

10. A filament break detection and correction system comprising:

a. a filament supply means b. a filament sensor body having a conduit therein of a size sufficient to allow the filament and a gas to pass therethrough,

c. means for directing a gas into said conduit in the direction of movement of said filament to urge said filament through said conduit and to provide a predetermined pressure in said conduit. and

d. means responsive to a change in pressure in said conduit indicating filament breakage for advancing the broken filament from said supply means into said conduit.

11. A filament break detection and correction system as set forth in claim 10 wherein said filament supply means includes a supply reel having filament wound thereon, and wherein said advancing means includes means for rotating said reel to advance the broken filament therefrom, and means for guiding the filament from said reel into said conduit.

* i I I. i

Claims

1. A filament break detector device comprising: a. a filament sensor body having a conduit therethrough, said conduit being of a size sufficient to allow a filament to pass endwise through said conduit and a gas to pass about the filament in the conduit, and a port communicatively connecting the conduit to the exterior surface of the sensor body, b. means for directing a gas into and through said conduit in the direction of movement of said filament to urge said filament through said conduit and to provide a predetermined pressure in said conduit, and c. means communicatively connected to the port of the sensor body responsive to changes in pressure in the port of the sensor body as a result of filament breaking for indicating filament breakage.

2. The filament break detector of claim 1 wherein the sensor body has a plurality of conduits, a pressure port communicatively connecting each conduit to the exterior surface of the sensor body, and a means communicatively connected to each pressure port responsive to changes in pressure in the port of the sensor body as a result of filament breaking for indicating filament breakage.

4. The filament break detector of claim 2 wherein the conduits through the sensor body are tubes arranged in one or more rows in a spaced relationship.

6. A filament break detection and correction system having in combination: a. a filament sensor body having a conduit therethrougH said conduit being of a size sufficient to allow a filament to pass endwise through said conduit and a gas to pass about the filament in the conduit and a port communicatively connecting said conduit to the exterior surface of the sensor body, b. a filament supply means, c. means for advancing filament from the filament supply means through the conduit in the sensor body to a pull means, d. gas supply means for providing gas flow through the conduit in the sensor body, and e. means communicatively connected to the port of the sensor body, responsive to changes in pressure in said port resulting from a broken filament being pulled past said port by said pull means, for activating the means for advancing filament from the filament supply means through the conduit in the sensor body to the pull means.

7. A filament break detection and correction system comprising: a. a filament sensor body having a conduit therethrough said conduit being of a size sufficient to allow a filament to pass endwise through said conduit and a gas to pass about the filament in the conduit, and a port communicatively connecting said conduit to the exterior surface of the sensor body, b. a filament supply magazine comprising a magazine body having a filament outlet, a supply reel, filament wound about said supply reel, and means for mounting said reel within said supply magazine to permit rotation of said reel, c. means for imparting angular rotation to said filament supply reel whereby filament is released from said reel through the filament outlet, d. guide means providing a passageway from the filament outlet through the conduit in the sensor body to a pull means, e. means for advancing filament along the guide means into the pull means, f. gas supply means for providing gas flow through the conduit in the sensor body, and g. means communicatively connected to the port of the sensor body responsive to changes in pressure in said port resulting from a broken filament being pulled past said port for actuating the means for advancing filament from the filament supply magazine through the sensor body to the pull means.

10. A filament break detection and correction system comprising: a. a filament supply means, b. a filament sensor body having a conduit therein of a size sufficient to allow the filament and a gas to pass therethrough, c. means for directing a gas into said conduit in the direction of movement of said filament to urge said filament through said conduit and to provide a predetermined pressure in said conduit, and d. means responsive to a change in pressure in said conduit indicating filament breakage for advancing the broken filament from said supply means into said conduit.