US3025195A

US3025195A - Fiber depositor and method for distributing cut fiber and plastic

Info

Publication number: US3025195A
Application number: US755246A
Authority: US
Inventors: Kozma Otto
Original assignee: Ibis Enterprises Ltd
Current assignee: Ibis Enterprises Ltd
Priority date: 1958-08-15
Filing date: 1958-08-15
Publication date: 1962-03-13
Anticipated expiration: 1979-03-13

Description

March 1962 o. KOZMA 3,025,195

FIBER DEPOSITOR AND METHOD FOR DISTRIBUTING CUT FIBER AND PLASTIC Filed Aug. 15, 1958 5 Sheets-Sheet 1 IN VEN TOR. 0 7 70 KOZMA A TTOE/VEY March 13, 1962 o. KOZMA 3,025,195

FIBER DEPOSITOR AND METHOD FoR DISTRIBUTING CUT FIBER AND PLASTIC 3 Sheets-Sheet 2 Filed Aug. 15, 1958 INVENTOR. 07-70 KOZMA 0. AND

March 13, 1962 KOZMA 3,025,195

FIBER DEPOSITOR METHOD FoR DISTRIBUTING (,UT FIBER AND PLASTIC Filed Aug. 15, 1958 3 Sheets-Sheet 5 J INVENTOR.

U 7 7 0 KOZMA BY @a,%m [flaw 3,25,l95 Patented Mar. 13, 1962 3,025,195 FIBER DEPOSITOR AND METHOD FOR DISTRIB- UTING CUT FIBER AND PLASTIC Otto Kozma, Cleveland, Ohio, assignor, by mesne assignments, to Ibis Enterprises Limited, Hamilton, Bermuda, a corporation of Bermuda Filed Aug. 15, 1958, Ser. No. 755,246 13 Claims. (Cl. 83-24) This invention relates to improvements in a fiber distributor and more particularly to a fiber distributor for a plastic depositor apparatus.

One of the objects of the present invention is to provide a construction for separating and distributing fibers for deposit in random orientation on a surface.

A further object of the present invention is to provide in a plastic depositor apparatus a fiber dispersing means for separating and distributing fibers so that they are directed in an organized stream in random orientation onto a surface with the fibers thereon wetted by plastic to provide a reinforced plastic laminate thereon with the fibers oriented in substantially evenly distributed random orientation.

A further object of the present invention is to provide a device for separating and distributing fibers for deposit in random orientation with this device including a venturi, a vortex producing means, means to prevent substantial back flow of the fibers during agitation thereof, and/ or to deposit the fibers on a surface in random orien tation without undesirable disturbance of the fibers deposited on the surface.

A further object of the present invention is to provide a fiber distributing apparatus characterized by its structural simplicity, economy of manufacture, and ability to separate and distribute fibers from a group into individual fibers for deposit in evenly distributed random orientation on a surface.

Other features of this invention reside in the arrangement and design of the parts for carrying out their appropriate functions.

Other objects and advantages of this invention will be apparent from the accompanying drawings and description and the essential features will be set forth in the appended claims.

In the drawings,

FIG. 1 is a perspective view of the plastic depositor apparatus;

FIG. 2 is a vertical, longitudinal sectional view taken generally along the line 2-2 of FIG. 1;

FIG. 3 is a transverse sectional View taken along the line of 3-3 of FIG. 1 with the surrounding band removed;

FIG. 4 is an enlargement of a portion of FIG. 2; while FIG. 5 is a schematic view of the operation of the apparatus.

Before the apparatus here illustrated is specifically described, it is to be understood that the invention here involved is not limited to the structural details or arrangement of parts here shown since an apparatus or structure embodying the present invention may take various forms. It is also to be understood that the phraseology or terminology herein employed is for purposes of description and not of limitation since the scope of the present invention is denoted by the appended claims.

The apparatus disclosed herein is a fiber depositor apparatus for depositing lengths of fibers in random orientation on a surface to form a reinforced plastic construction. This apparatus is especially designed to replace the hand lay-up method of making glass fiber reinforced plastic products.

' The apparatus has a frame in FIGS. 1 and 2. Tubular handle 10, having handle grips 11 secured at its opposite ends, is secured at its mid-portion by screws 12 to left side wall 13 of the frame. Right side wall 14 is secured in parallel relationship to wall 13 by

spacers

15, 15 and 16 in FIG. 2 detachably secured at opposite ends to these walls by screws 17. Spray nozzle manifold tube 18 is clamped intermediate its end in wall 13 by screws 12.

Cutter unit 20 cuts and feeds glass fibers in appropriate fiber length toward the surface 21a on article 21 to be coated, as in FIG. 5. Electric motor 23 in FIG. 1, mounted on wall 13 and controlled by electric switch 2 on handle 11, rotates rubber sleeve in FIG. 2, which sleeve rotates cutter drum 28 by peripheral contact friction. Drum 28 and sleeve 26 are rotatably supported on parallel shafts between walls 13 and 14. Continuous fiber glass roving 30 is fed in FIG. 2 into the apparatus by having one or more bundles of continuous fibers threaded through one or more guide holes 32a in roving guide shoe plate 32 pivotally carried on spacer 16; then between rubber sleeve 34, rotatably mounted between walls 13 and 14, and portion 32b of plate 32 biased counterclockwise into tangential contact with said sleeve 34 by tension spring 35, secured at opposite ends to portion 32b and spacer 16, to provide frictional drag on the roving; and then between sleeve 26 and drum 28. As motor 23 is driven, sleeve 26 and drum 28 rotate in the direction of the arrows on FIG. 2 to draw the roving 3i therebetween; and radially extending cutters 28a on drum 28 chop the roving into desired lengths 3%, determined by the peripheral arcuate distance between cutters 28a, and feed the fibers toward the right in FIG. 2.

A spray unit 33 is provided in FIG. 1. Air tube 13 supplies air from a source through line 39, valve and line 36 to spray

heads

37 and 38 for dispersing rwpectively accelerated resin and catalyzed resin, which comprises the plastic compound, in flow under pressure from resin handle grips 11 and depresses switch 24- and valve 41.

The plastic streams from the

heads

37 and 38 converge in FIG. 5 on the travel path 465 of fiber lengths 30a traveling at 40a and then the wetted fibers are deposited on surface 21a. After each layer is deposited on article 211, it is rolled down by hand to make an air free laminate.

Heads 37 and 33 are mounted by ball and socket joints 37d and 38d to'opposite ends of tube 18 so that the angle of the heads may be adjusted to suit the dispersion pattern of the fibers 30a in path 40.

Of course, if desired, the fibers Stia may be chopped and deposited on a previously or subsequently wetted surface Zlla without using spray heads 3'7 and 38, by keeping valve 41 in off position.

Variations in structure and use readily come within the scope of this invention. Although the specific cutter unit 20 has been disclosed, it should be readily apparent that any suitable feeding means may be provided on the frame for feeding in groups fiber length 30a along their path of travel to surface 21a. Also not only glass fibers but also any other suitable material may be used in the apparatus.

With heretofore described apparatus, the problem sometimes occurs that the fiber lengths 30a do not distribute themselves evenly over the surface 21a in random orientation but instead are oriented in generally the same direction or are arranged in piles or windrows. Uniform fiber distribution in random orientation is necessary to provide article 21 with a high mechanical strength, desirable characteristics, and a generally homogenous construction. If the fiber lengths are oriented generally in the same direction or are arranged in piles with low points therebetween, it should be readily apparent that article 21 will have a low strength and will not be satisfactorily made. If the group of fiber lengths 30a do not naturally separate themselves into their constituent fibers as they are ejected by cutter unit 20, it is desirable to provide a fiber dispersing means 50 for separating and distributing the fiber lengths 30a by a suitable disrupting force applied thereto so that the fibers will be directed in an organized stream 40 in random orientation onto surface 21a.

This fiber distributing means 50 includes a member 60 detachably secured by clamp 52 to air manifold tube 18. Clamp 52 includes a bracket 53 suitably telescopically secured to tube 18 and having a slot 53a extending therethrough within which one end of strap 54 is clamped by screw 55 threaded in bracket 53. The other end of strap 54 is welded or otherwise secured to a. portion of member 60.

Member 60 has a through bore 61 therein serving a passageway for the fiber lengths 30a in their travel along path 40 with this bore having inlet end 61a for receiving fibers fed by cutter unit 20 and outlet end 61b for directing the dispersed fibers toward receiving surface 21a.

While traveling through bore 61, suitable fiber distributing means separates and distributes the fibers within this bore so that they will be directed in an organized stream in random orientation onto surface 21a. Bore 61 has formed therein a venturi having a venturi throat 60a with an annular shoulder 6% at the throat of the venturi to provide a sudden increase in the transverse dimension of bore 61 on the downstream side of throat 60a.

The fiber distributing action is aided by injected fluid agitating the fibers. This fluid, such as air, is supplied from a pressure source 39 in FIG. 1 and line 62 having a controlling needle valve 64 for adjusting the fluid pressure from the source to jet ports 60c, through hole 60d in member 60, through an annular header 66 formed by peripheral groove 600 in member 60 surrounded by a. band 67 clamped around member 60 by the screw and nut connection 68, and inwardly through the equally spaced ports 60c providing fluid injection jets directing the fluid into the bore 61. These ports 60s are located downstream from shoulder 6%. Each port 60c is in clined in the downstream direction toward the center of the passageway at an angle A, is inclined at an angle B to. a radius of bore 61 to be generally tangential to a circle located in bore 61 transverse to the path of fiber travel. It has been found that satisfactory results are obtained with the following approximate dimensions: A=9-ll, B=l-l7, C=9-11', and the diameter of each port 60e being 0.03125 inch to 0.0625 inch. Angle C is the angular relationship of the frustoconical surface 60f of member 60 gradually increasing in diameter in the downstream direction from the jet forming ports 602, to form the gradual expansion of the venturi.

The mode of operation now should be readily apparent. The fiber lengths 30a, ejected from cutter unit 20, will be properly separated and dispersed, whether these fibers entering inlet end 61a be laterally dispersed or compactly associated together in a bundle or group.

The venturi shape of bore 61 will cause the air carried by the fibers 30a to increase in velocity at the venturi throat 60a The air jets from ports 60c will produce a vortex action to provide a rapidly rotating air stream with this rotating motion transferred to the fibers 30a to provide disruptive forces for breaking up the fiber bunches by high centrifugal forces. In a vortex, as the distance from the center increases, the velocity decreases and the pressure increases. The jets from ports 6012, directed tangentially to the vortex flow, agitate the fibers within bore 61. However, it should be readily apparent that any other suitable vortex flow producing means might be used.

The quantity of air emerging through ports 60c may be controlled by adjusting throttling needle valve 64 so that the inrushing air breaks up the fiber groups into individual fibers for random orientation on surface 21a without adversely disturbing the fiber deposit pattern on this surface in any manner, such as by creating too strong an axial blast of air that might tend to blow the fibers off this surface. The quantity and velocity of air is sufficient to supply the disruptive energy necessary to break up the fiber bunches. The preferred quantity and velocity of air is dependent on the length of chopped fibers and type and quantity of fibers. Longer fibers or a greater quantity of fibers requires more air. However, large excess air flow is undesirable because of disturbing effects on the deposit on surface 21a. It is preferred that the fibers 30a should land on surface 21a by inertia forces instead of by carrier air flow.

It is preferable that strap 54 be adjusted in bracket 53 so that the distance between cutter unit 20 and member 60 is so adjusted that the effective diameter of the rotating air stream vortex from ports 60:: is very close to the group diameter, or transverse dimension thereof, of the fiber groups fed into bore 61 and coincides therewith.

Means is provided for resisting any tendency of fibers 30a to back flow through the bore 61 caused by the agitation of the vortex. The shoulder 60b is a step in the bore to reduce the tendency for any of the air injected through ports 60c from traveling back upstream. The venturi throat 60a, located on the upstream side of the vortex producing jets 60c, increases the velocity of the air flowing through bore 61 to provide an induced flow for sweeping the fibers 30a forwardly and to minimize back flow. The fluid jet ports 60c, being inclined forwardly at an angle A, exert a forward component of force on the fibers 30a in their movement along path 40 to sweep these fibers forwardly. However, the forces caused by the inclination of jet ports We at angle A in the forward or throwing direction are modest (about the same order as achieved by fiber discharge from cutter unit 20 without member 60). If the forward forces are too great, there is always the danger of having the excess air disturb the random orientation condition of the fibers in three dimensions after they emerge from the discharge end 61b.

The gradually enlarging surface 60 provides a gradually increasing diameter in bore 61 in the downstream direction from the vortex ports 602 so as to expand the roving or fibers into individual filaments in a uniform pattern of distribution. This smooth expansion controls the size of the pattern. This expansion of the venturi also slows down the speed of the air traveling axially through bore 61 so that high speed air doesnt disturb the random distribution of the fibers. However, a modest axial flow is still maintained.

The venturi shape of bore 61 permits control of the air stream to meet the desired conditions. The air travels at higher speeds and lower pressure through throat 60a, but expands and travels more slowly as it moves axially forwardly along the length of surface 60 These differences in pressure and velocity, caused by the venturi shape, also help add to the agitation of the fibers.

Now, it should be apparent that the fibers 30a land on surface 21a in random orientation of substantially uniform distribution. Also, the air flow is not so great as to disturb adversely the fiber deposit on surface 21a. It will not blow the previously deposited fibers off the surface 211: or cause the fibers to bunch up as they are deposited.

Various changes in details and arrangement of parts can be made by one skilled in the art without departing from either the spirit of this invention or the scope of the appended claims.

What is claimed is:

1. A fiber depositor apparatus for depositing lengths of fibers in random orientation on a surface comprising, a frame, fiber dispersing means on said frame for separating and distributing fibers so that they are directed in an organized stream in random orientation onto a surface, and feeding means on said frame for feeding in groups fiber lengths into said dispersing means in their path of travel to said surface; said dispersing means including a passageway for said fibers along their path of travel, and fiber distributing means for separating and distributing the fibers within said passageway so that they are directed in an organized stream in random orientation onto said surface, said fiber distributing means including vortex means for producing a vortex flow Within said passageway in the path of fiber travel.

2. An apparatus, as set forth in claim 1, with said vortex means including fluid inlet jets arranged around said passageway and directed tangentially in generally the same direction to said vortex flow, and including means for supplying said jets with fluid from a pressure fluid source.

3. An apparatus, as set forth in claim 2, with said vortex means including means for adjusting the fluid pressure from said source to said jets so that the fluid breaks up the groups into individual fibers for random orientation on said surface without adversely disturbing the fiber deposit pattern on said surface.

4. An apparatus, as set forth in claim 1, with adjustable means for orienting said feeding means and fiber distributing means on said frame so that the transverse dimension of the fiber groups fed into said dispersing means by said feeding means coincides with and is approximately equal to the effective diameter of the vortex flow.

5. An apparatus, as set forth in claim 1, with means on said frame for resisting any backflow through said passageway of said fibers caused by said vortex means.

6. An apparatus, as set forth in claim 5, with said backflow resisting means including a step in said passageway with an inwardly directed shoulder located on the upstream side of said vortex means.

7. An apparatus, as set forth in claim 5, with said backflow resisting means including a venturi throat on the upstream side of said vortex means.

8. A fiber depositor apparatus for depositing lengths of fibers in random orientation on a surface comprising, a frame, fiber dispersing means on said frame for separating and distributing fibers so that they are directed in an organized stream in random orientation onto a surface, and feeding means on said frame for feeding in groups fiber lengths into said dispersing means in their path of travel to said surface; said dispersing means including a passageway for said fibers along their path of travel, and fiber distributing means for separating and distributing the fibers within said passageway so that they are directed in an organized stream in random orientation onto said surface, said fiber distributing means including a venturi formed in said passageway through which said fibers pass in their movement path, said fiber distributing means located near the throat of the venturi and surrounding said passageway for agitating said fibers within said passageway, said venturi having a gradually increasing diameter in said passageway in the downstream direction from said agitating means.

9. Apparatus for dispersing in random orientation lengths of fibers fed thereto, comprising a member having a bore therethrough as a passageway with said bore having an inlet end for receiving fed fibers and an outlet end directing the dispersed fibers toward a receiving surface, said passageway formed into a venturi with an annular shoulder at the throat of the venturi to provide a sudden increase in the transverse dimension of said passageway on the downstream side of said throat, said member having fluid injection jets directing fluid into said passageway and located downstream from said shoulder and equally spaced about said passageway, each jet being inclined in the downstream direction toward the center of said passageway and being generally tangential to a circle located in said passageway transverse to the path of fiber travel, said passageway gradually increasing in diameter in the downstream direction from said jets.

10. Apparatus as in claim 9 mounted on a frame, and wherein fiber-cutting means including a rotating roll is mounted on said frame in position to throw out fibers from said roll into said inlet end of said bore.

11. Apparatus, as set forth in claim 10, with adjustable clamp means connecting said roll and member for relative movement so that the transverse dimension of the fibers fed by said roll into said inlet end coincides with and is approximately equal to the effective diameter of the vortex produced by said jets.

12. A method of depositing lengths of fibers in random orientation on a surface, comprising feeding in groups fiber lengths in a conveying fluid along a path of travel toward said surface, decreasing the pressure and increasing the velocity of said fluid at a zone along said path, and subsequently suddenly dropping the pressure of said fluid and simultaneously applying a vortex motion to said fiber lengths immediately downstream from said zone for swirling the fiber lengths around the general axis of said path while said fiber lengths advance along said path so that said fibers are deposited in random orientation on said surface.

13. A method, as set forth in claim 12, with the steps of feeding said fiber in a continuous length, cutting said fiber into groups of fiber lengths, and then feeding in groups said fiber lengths in the manner described.

References Cited in the file of this patent UNITED STATES PATENTS 2,136,158 Thomas Nov. 8, 1938 2,317,895 Drill Apr. 27, 1943 2,787,314 Anderson Apr. 2, 1957 2,850,421 Thompson Sept. 2, 1958 2,860,687 Cole Nov. 18, 1958 2,929,436 Hampshire Mar. 22, 1960 FOREIGN PATENTS 1,124,895 France July 2, 1956

Claims

12. A METHOD OF DEPOSITING LENGTHS OF FIBERS IN RANDOM ORIENTATION ON A SURFACE, COMPRISING FEEDING IN GROUPS FIBER LENGTHS IN A CONVEYING FLUID ALONG A PATH OF TRAVEL TOWARD SAID SURFACE, DECREASING THE PRESSURE AND INCREASING THE VELOCITY OF SAID FLUID AT A ZONE ALONG SAID PATH, AND SUBSEQUENTLY SUDDENLY DROPPING THE PRESSURE OF SAID FLUID AND SIMULTANEOUSLY APPLYING A VORTEX MORTION TO SAID FIBER LENGTHS IMMEDIATELY DOWNSTREAM FROM SAID ZONE FOR SWIRLING THE FIBER LENGTHS AROUND THE GENERAL AXIS OF SAID PATH WHILE SAID FIBER LENGTHS ADVANCE ALONG SAID PATH SO THAT SAID FIBERS ARE DEPOSITED IN RANDOM ORIENTATION ON SAID SURFACE.

13. A METHOD, AS SET FORTH IN CLAIM 12, WITH THE STEPS OF FEEDING SAID FIBER IN A CONTINUOUS LENGTH, CUTTING SAID FIBER INTO GROUPS OF FIBER LENGTHS AND THEN FEEDING IN GROUPS SAID FIBER LENGTHS IN THE MANNER DESCRIBED.