US2639487A - Air blower for linearly feeding a continuous strand - Google Patents

Description

May 26, 1953 w. B. KELLEY 2,639,487

AIR BLOWER FOR LINEARLY FEEDING A CONTINUOUS STRAND Filed Aug. 30, 1951 3/ I?) l I i I llllllllllll m I m l0? I v 32 I /4 E h I fl llllllllllr 3/ A r E 32 25 23 INVEIYTOR. r----- 3/ l Y/Mam 5. Aefley FIE-j. i L

Patented May 26, 1953 AIR BLOWER FOR LINEARLY FEEDING A CONTINUOUS STRAND William B. Kelley, Pawtucket, R. I., assignor to Owens-Corning Fiberglas Corporation, a corporation of Delaware Application August 30, 1951, Serial No. 244,405

3 Claims.

This invention relates to an air blower parposition of strands of tough fibrous material such as glass fiber strands on the sheet material in heterogeneous arrangements of swirls and loops. The method of the Roberts patent contemplates that the fibrous material shall be fed at a relatively continuous linear rate and delivered onto a travelling sheet of material to be reinforced in random swirls and loops which, when adhered to the material by compression between the receiving sheet and a covering sheet or by adhesive spread on or between the sheets, will greatly strengthen and reinforce the paper by distributing stresses over large areas of its surface.

In order to effectively project the strands onto a travelling web of the material to be reinforced,

it is best to project them linearly through the air allowing the natural resistance of air to their travel to cause them to fall in random overlay loops and swirls.

It is, therefore, the principal object of this invention to provide an air blower for delivering continuous strands of material such as glass fibers in such a manner that the strands will swirl and loop and can be projected onto a sheet material to be reinforced.

It is a more specific object of this invention to provide an air blower through the axis of which a continuous strand of glass fibers can be fed by air pressure and which blower is so designed as to eliminate the necessity for close machining in order to provide for a constant rate of feed of the air through the blower and, consequently, of the strand.

More specific objects will be apparent from the specification and drawings in which:

- Fig. 1 is a generally schematic view in eleva- Fig. 4 is a sectional view taken along the line 4-4 of Fig. 3.

In the machine schematically illustrated in Figs. 1 and 2 a supply of continuous strands IU of tough fibrous strands, such as glass fiber strands, is provided in the form of a plurality of spools H which are mounted .upon a frame l2. Each of the strands In is led through a guiding eye I3 and then around the periphery of a driven feeding drum l4. Frictional engagement between the surface of the drum l4 and each of the strands In feeds the strands off the spools ll. Each of the strands is then led around and through the guiding eye [3 a second time and then through a central passageway [5 in a blower head [6 to which a supply of air under pressure is fed. In a manner to be described below the strand ID is projected to the right in Fig 1 from the blower head I6 at a substantial linear rate of feed. Air resistance to its movement causes the strand to gradually slow up as it proceeds farther away from the blower head 16 and it falls in random loop and swirl patterns on a continuously moving web I! of the material to be reinforced. The web I! is fed up an inclined table l8 providing the surface on which the random loops and swirls of strand I0 fall. After the strands fall on the web I! it is laminated with a second web I9 by means of pressure rollers 20 and then passes clown and around a tensioning roller 2| and onto a cutting table 22. When making reinforced laminated paper, asphalt or other adhesive may be applied to the web ll before it reaches the zone of strand deposition.

Each of the blower heads It consists of a machined body 23 and a generally fiat cover plate 24. The body 23 has an annular groove 25 cut in one of its faces concentric with a center bore 26 and that forms an annular chamber in communication with an air pipe 21 that is threaded into a radial hole 28 drilled through the body 23. The cover plate 24 has a central opening 29 coaxial with the bore 26 in the body 23 and having a flared inlet'to facilitate original insertion of a strand [0 to be fed thereby. A gasket 30 may be provided to tightly seal the plate 24 to the body '23 and a plurality of studs 3| may be threaded into tapped holes spaced around the rim of the body 23.

A plurality of inclined orifices 32 are drilled through the shoulder of a sleeve-like portion 33 of the body 23 which surrounds the central bore 26. The orifices 32 are spaced circumferentially from each other and inclined inwardly at an angle of less than 45 to the axis of the blower 16. Their outer ends lead to the annular space 3 formed by the groove 25 and inner face of the cover 24. Each of the orifices 32 functions to provide a straight jet of air along a line such that the force created thereby has its major components along the axis of the blower [.16. .By reason of their being. aplurality t circumferenfiiall-y spaced orifices 32, the radially directed components of the forces balance each other and the strand I0 is maintained generally at the center tion of the jet orifices" and "thus" the cubicfeet of air fed per minute for a certain pressure and,

consequently; th'eforc'es' acting onthestrand and the resultant rate 01. feed or the strand constitutes an important .snnplification over the jet head's" orblowers illustrated in Patent 23923882 to Roberts. In thezstruc'ture' of that patent carefill controlover'tbe machining or the mating portions or tlieblower' liea'dis essentialto maintain the, air passageways at a constant and. predetermined cross section. on the other-inane, in a blower embodying the instant invention no close tolerances are required.

The effective cross sectional areaoi the annular space formed by the groove 2!- andf inside ofithe cover plate 24' is substantially larger than the t'otaliicros'ssectional, area oi. the, orifices. Therefore, the dimensions of the annularspace are not critical andcontrol of rate or iee'doftne airior any given pressure depends solely upon the orifices 3'2 themselves.

comparative tests made between a; blower construction according to the showing Off the above mentioned, patent; and .a blomroomtructed according to the teachings; of tnelinsjtant application reveal that'iliorder to-oroduoe the same linear feed of the same type ofstranditneblower illustrated in'the patent mustbeopierated at-ia gauge pressure of rap". s.,i., anolrequires approximatel'y tcubie' feetiofiair germinate while a blower embodying the instant inventini-operates at only'5 ounds gaugepressure andconsumes only one cubicifoot of air per minute.

Thus not only does a blower embodying thejnstant' invention represent a simplification firom the standpoint. of manuiaoturabut. it is believed that by eliminatingxtheswirling movement'ot the air. in the central orifice ornassageway or the blower itself the jet forceis more eftectively employed in entraining and progressing the strand to be delivered.

The precise nature oitthe, improvements in construction constituting. th instant invention are set. forth. in the claims wniontoll'owi;

Having described.thecinvention.I claim:

.1. An air. blower for linearly; ieediugacontinu ous strand comprising, in combination, a body having an axial bore and a radially spaced annular groove cut in said body concentric with said bore, a centrally bored cover for such annular groove, secured to said. body and forming with such: groovexan annular space in communication with a source of air under pressure, the bore in said cover being axially aligned with the bore in said body, said body having a generally sleeve-like portion: surrounding said axial bore, .there being a plurality of circumferentially spaced ,,inclined orifices in said portion communiciatingbetween said annular space and said axial bore for delivering radially balanced jets of air into said axial bore for feeding a strand therethrough.-

2. An air blower for linearly feeding a continuous strand comprising, in combination, a generally cylindrical body having an axial bore and aradial'ly spaced annulargroov'e' cut oneend face of said b'o'dyconcentric with said-boraa centrallyboreo cover for such annular groove; secured to the end of. said'body and iormingwith such groove an annular space in communication with a source of air under pressure, thebore: in said cover being axially aligned with the bore in said body, said body-having agenerally annular, sleeve-like portion surrounding said axial bore and iorming' the insid wall or said annular groove, a plurality of, orifices through said sleevelike portion connecting said'annular space and said" axial bore, ,said orificesbeing. circuniijer ential'ly spaced and inclined to the axis of said body at an: angle less: than 925 wherebytl e resolution of forces created'by air 'jfettirl'g'through said orifices isfiba'lanced' radially and feeds a strand:introduced'through the bore in said cover axially through theibore said body, roje t ng said strand therefrom.

3. An air blowerior lineariyjeeding a continuous strand omprising in combination, a body having a. longitudinal borea'nd a radially spaced groove out, insaitt body concentric with bore, a'bored cover for such groove' secured' to said body andforming with suclrgro'oye' a spaceflin communication with. aisource' of air under pressure, thebore in said cover beingaligned the bore, in. said body, said body liaving a generallysleevedilie p o'rtion srmonnding said bore, there being a plurality of oircnrnrerentialiy spaced, inclined orifices in saidlportifon communicatingibetwjeen said space and said' bore for delivering radially balanced jets of air into said boreior, feeding a strand therethrouglr.

- References; Cited: ill-thiefile: of. patent UNITED STATEST PATENTS Number Name Date 2' ,3'0217'90' Modigliani Nov'., 24,1942

FOREIGNTATENTS Number Country Date $553,896 Great-Britain .-i June-9,1943

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