US3023729A - Metering device and method - Google Patents

Description

March 6, 1962 R. 1.; HAYDEN ET AL 3,023,729

METERING DEVICE AND METHOD INVENTORS Q m efd wope ATTORNEYS Filed Feb. 14, 1958 United States Patent 3,023,729 METERING DEVICE AND METHOD Ralph L. Hayden, Vienna, and Ralph R. Steele, Parkersburg, W. Va., assignors, by mesne assignments, to

Johns-Manville Fiber Glass Inc., Cleveland, Ohio, a

corporation of Delaware Filed Feb. 14, 1958, Ser. No. 715,229 2 Claims. (Cl. 118234) The present invention relates broadly to the treatment of continuous strands of textile materials and more particularly to a method and apparatus especially adapted for applying predetermined amounts of liquid sizes, binder or lubricants to textile strands.

This invention is of particular utility and will be described herein with reference to the coating of strands of glass fibers produced by grouping endless filaments of glass that are drawn and attenuated to extremely fine diameters. However, it is to be understood that the invention may also be used in connection with other processes and, in general, is adapted for use wherever filaments, natural or synthetic, are grouped and coated to form substantially continuous strands.

In forming continuous strands from finely drawn glass filaments, where the filaments are grouped into strand form by passing said filaments over a guide, the common practice is to provide the guide with applicator means for supplying a liquid coating material, such as a lubricant, size or binder, to said filaments. The liquid lubricant, binder or size serves to prevent the filaments within the strand from scratching each other, or the coating may serve to give mass integrity to the group of filaments in strand form, thereby preventing loose ends from fraying or breaking apart from the strand.

it is customary in coating strands by the aforementioned method to provide the guide with a pad of felt or other absorbent material. The pad is then saturated with the liquid coating material and serves to wipe the coating liquid onto the filaments as they pass thereover. The liquid is usually applied to the absorbent pad by means of a flexible tube positioned directly over said pad and connected directly to a liquid supply line.

Ordinarily, in the above-described system, where the liquid is allowed to flow from a tube suspended above the applicator pad onto said pad, a valve is provided in circuit with the flexible tube in order that an operator may adjust the flow so that the pad is kept completely saturated with the liquid coating material thereby assuring a proper wiping action of the filaments passing thereover.

It has been found however that, in actual practice, the operator seldom makes the proper adjustment for providing an optimum flow of liquid coating material onto the applicator pad. Thus an operator sometimes may close the valve to too great an extent, and this in turn results in an incomplete saturation of the pad and improper coating of the strand. The more usual failing is that the operator will open the valve to too great an extent, which of course insures saturation of the applicator pad but, in turn, results in flooding the pad with the liquid coating material. The latter case, although resulting in a proper coating of the strand, results in an excessiveloss of coating material, which results in excessive production costs in the over-all commercial operation.

The present invention aims to overcome the afore mentioned dificulties by providing a novel method and apparatus whereby predetermined quantities of liquid coating materials may be metered onto the applicator pad.

It is another object of this invention to provide a novel metering device which permits the application of predetermined amounts of liquid coating material at an optimum and uniform flow and which, at the same time, does not require periodic valve adjustments in the liquid supply line.

Other objects and advantages of the invention will become apparent from the following description taken in conjuncton with the drawings.

In the drawings, wherein like numerals are employed to designate like parts throughout the same:

FIG. 1 is an elevational view of the apparatus of this invention shown in conjunction with two filament forming and drawing devices in series;

FIG. 2 is an enlarged sectional view of the metering deevice of this invention taken along the line 22 of FIG. 1;

FIG. 3 is an enlarged sectional view taken along the line 3-3 of FIG. 2;

FIG. 4 is a side view of FIG. 2; and

FIG. 5 is a side view of the sealing member.

Referring now to the drawings, and particularly to FIG. 1, the letter A designates generally a filament forming and drawing apparatus for mechanically drawing and attenuating molten glass in the form of continuous fine glass fibers or filaments. This apparatus comprises a container or bushing 10 for molten glass. The molten glass flows from the container through a plurality of small orifices in the bottom thereof in the form of individual streams of molten glass and these streams of molten glass are drawn downwardly and attenuated into fine glass fibers or filaments 11 by means of a winding spindle 12 on which the fibers are wound to form a package with the aid of a suitable traverser 13, as is well known in the art.

Located intermediate the bushing 10 and winding spindle 12 is a guide, indicated generally by the numeral 14, adapted to group and combine the filaments 11 into a strand 15 and to apply a suitable size, binder or other liquid coating material to the filaments substantially at the point at which they are grouped. The guide 14 ordinarily comprises an arm or plate 16 provided with an applicator pad 17 of felt or other suitable absorbent material for receiving the coating liquid as it flows from the flexible tube 18 and for wiping said liquid coating material onto the filaments as they are drawn thereover.

The liquid supply apparatus which is designed to provide for a predetermined optimum and uniform flow of liquid coating material onto the applicator pad is indicated generally by the numeral 19. This apparatus comprises a reservoir 20 for storing the liquid coating material and a conduit 21 through which the liquid is forced from the container under a constant pressure by means of a pump 22 interposed in the conduit 21. Carried by the conduit, at a point above the applicator pad 17, is a metering device, indicated generally by the numeral 23, and leading directly from this metering device to a position directly over the applicator pad 17 is the flexible tube 18 for supplying a constant flow of liquid coating material to said applicator pad.

The metering device 23 comprises a housing 24, a readily compressible sealing member 25 located in said housing, a backing plate 26 secured to the housing, and a needle or capillary tube 27, extending through the sealing member. The housing 24 is shown as being in the form of a rectangular block having a circular hole 28 drilled therethrough, and being secured to the conduit 21 by suitable means such as by welding or the like. Circular holes 29 and 30 are provided, respectively, in the conduit 21 and backing plate 26. The holes 29 and 30 are in alignment with one another and are relatively smaller than the hole 28 in the housing, being disposed centrally thereof.

The sealing member 25 is preferably formed of rubber and comprises a body portion 31 having two oppositely directed nipple- like protuberances 32 and 33. The body portion 31 is received within the opening 25 in housing 24, with the protuberance 32 projecting through the hole 30 in backing plate 26 and the protuberance 33 projecting through the hole 29 in the conduit 21. A hole 34 is drilled centrally through the body portion 31 and nipple-like protuberance 32, as shown by the dotted lines 34 in FIG. 5,

while protuberance 33 is slit to form the two opposing lips 35 and 36.

In practice, the tube 27 is inserted through the hole 34 in the sealing member 25 so that the opposite ends of the tube project beyond the sealing member as shown in FIG. 3. The sealing member 25, carrying tube 27, is then positioned in the housing 24 so that the nipple-like portion 33 extends through hole 29 in conduit 21. The backing plate 26 is then suitably secured over the body 31 of the sealing member 25 and to the outwardly directed wall of the housing 24 such as by means of screws 37. The parts 31, 32 and 33 of sealing member 25 are all slightly larger than the respective holes in which they are positioned so as to provide a liquid tight sealbetween tube 27 and the housing 24, backing plate 26 and conduit 21 respectively.

It will be readily evident that the sealing member could be completely drilled therethrough to receive the tube 27. However, it has been found, in actual practice, that a more perfect seal results between the walls of hole 29 and tube 27 if the nipple-like member 33 is slit as shown in FIG. to provide the opposing lips 35 and 36 which serve to grip the tube 27. Finally, one end of the tube 18 is fitted over the outwardly projecting end of tube 27, with its opposite end in position over the applicator pad 17.

In operation, the liquid coating material in tank 20 is pumped through conduit 21 by means of pump 22 which maintains a constant pressure on the liquid in conduit 21. This liquid then flows under constant pressure through the metering device 23, by means of the needle or capillary tube 27, into and through the flexible tube 18 onto the applicator pad 17. The amount of liquid flowing through the tube 18 will be proportional to the size of the opening in, and the length of, the needle or capillary tube 27 and the pressure and viscosity of the liquid coating material in conduit 21. Once the optimum amount of liquid flow necessary for complete saturation of the applicator pad has been ascertained, the size and length of the capillary tube and the fluid pressure necessary for achieving this flow may be readily determined.

By way of example, it was determined that a flow of 76 cc. of liquid binder per minute would be the optimum flow required to saturate the applicator pad. The liquid binder in the supply conduit was under pounds pressure and the length of the delivery tube, extending from the metering device to the applicator pad, was 72 inches. The tube 27 in the metering device which would deliver the required flow was 1 /2 inches in length and had a 0.018 inch orifice.

It is also within the scope of this invention to encompass liquid supply systems diifering from that shown in FIG. 1. Thus, conduit 21 may be continued so as to connect into the reservoir 20, thereby forming a complete cycle. Also, a gravity feed of liquid coating material may be established by positioning the liquid reservoir above the metering device. The critical factor which must be maintained constant is the pressure of the liquid coating material entering the tubular portion of the metering device and other well-known apparatus which will accomplish this result are within the scope of this invention.

Also, as shown in FIG. 1, the metering apparatus of this invention may be employed to serve one or more additional filament forming and drawing devices B the only limitation being the elfective pressure which must be stituted for the guide 14,

As shown in the drawings, the needle or capillary tube 27 enters conduit 21 from the side. This arrangement is preferable as it places the entry orifice of the tube at a point well above the bottom of conduit 21, which may possibly contain sediment to a certain extent. It is contemplated, however, that the needle or capillary tube may be positioned in various parts of the conduit 21 and yet be within the scope of the invention.

It is to be understood that the form of the invention herewith shown and described is to be taken as the preferred embodiment of the same, and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the scope of the subjoined claims.

We claim:

1. An apparatus for supplying a predetermined and constant volume of liquid coating material to a plurality of glass fiber strands comprising a supply of coating material, a conduit connected to the liquid supply, pressurizing means to convey liquid coating from the supply through said conduit at a constant pressure, an applicator of liquid coating, a capillary tube, of constant internal cross-sectional area and being of a predetermined length, projecting into the passing stream within said conduit and being approximately at right angles to the direction of flow of the coating material so as to permit said coating material to exit at a predetermined rate as determined by the capillary characteristics of the tube, the pressure head on the coating material and the viscosity thereof, said tube projecting stant volume of liquid coating material to a plurality of glass fiber strands comprising a supply of coating material, a conduit connected to the liquid supply, pressurized means to convey liquid coating from the supply through said conduit at a constant pressure, an applicator of liquid coating, a capillary tube projecting into the passing stream within said conduit and being approximately at right angles to the direction of flow of the coating material so as to permit said coating material to exit at a predetermined rate as determined by the capillary characteristics of the tube, the pressure head on the coating material, and the viscosity thereof, a housing secured to said conduit encompassing the tube adjacent the conduit, a deformable sealing member within said housing and through which the tube passes, a portion of said sealing member comprising spaced lips projecting into the conduit, said lips being tightly engaged with said tube and the conduit wall to prevent leakage out of the conduit adjacent the tube, means to conduct coating material from the tube to the applicator, and means to combine a plurality of glass fiber strands into a single strand adjacent the applicator and to bring said glass fiber strands into contact with the coating material on the applicator.

References Citedin the file of this patent UNITED STATES PATENTS 1,208,664 Russak et al Dec. 12, 1916 1,449,342 Morrell Mar. 20, 1923 1,621,303 Altemus Mar. 15, 1927 1,934,796 Friederich Nov. 14, 1933 2,224,149 Fisher Dec. 10, 1940 2,373,078 Kleist Apr. 3, 1945 2,659,343 Kucher Nov. 17, 1953 2,693,096 Quinn Nov. 2, 1954

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