US2912041A - Core compactor - Google Patents

Description

H. D. BOGGS CORE COMPACTOR Nov. 10, 1959 4 Shecs-Sheet 2 Filed Jan. 28, 1954 j g) "3 J Ill 4 Sheets-Sheet 3 INVENTOR I 6 67/6497? flufigylfs' ATTORNEYS Nov. 10, 1959 H. D. BOGGS CORE COMPACTOR Filed Jan. 28, 1954 Win (A H. D. BOGGS CORE COMPACTOR Nov. 10, 1959 4 Sheets-Sheet 4 Filed Jan. 28, 1954 gall/ INVENTOR #9758750. 50 52535 BY mpw MW ATTORNEYS 2,912,041 Patented Nov. 10, 1959 Pi ce CORE COMPACTOR Herbert 'D. Boggs, Tulsa, Okla, assignor to H. D. Boggs Company, Ltd., Omaha, Nebn, a limited partnership This invention relates generally to a method and apparatus for making tubular formations of randomly dis- 1 tributed fibers. More particularly, this invention relates to the making of such tubular formations for use, for example, as reinforcing liners or blanks in so-called plastic pipe or tubing.

Representative methods 'and apparatus for producing such articles are disclosed and claimed in the copending applications of H. D. Boggs, Serial No. 200,l93,'filed December 11, 1950, now Patent No. 2,776,450 and Serial No. 264,976, filed January 4, 1952, now Patent No. 2,785,442 and in thecopending application of Lewis Perrault, Serial No. 391,821, filed November 13, 1953, all assigned to the assignee of the-present invention. These techniques involve impregnating a fibrous reinforcing liner with a thermo-setting plastic material. It has been proposed to make the initial fibrous reinforcing formation by wrapping sheets of matted fibrous material, such as glass fibers, about a mandrel or other form, inserting the thus-formed liner into a mold, then impregnating the liner of fibrous material with the liquid sealable matter by centrifugal or other forces, and then subjecting the entire mass to sufiicient heat to cure the'mate rial within a suitable molding apparatus.

It has been determined. that a considerable saving in both machinery and labor may be derived by the elimination of the use of material which has to be wound or otherwise formed on the mandrel as discussed above. Rather, it is now proposed to directly prepare tubular blanks or cores of matted fibers to serve as reinforcing liners, although the use of such blanks or cores is by no means so limited. In accordance with the present invention, the fibers are matted into a formation roughly approximating the size and shape, though not necessarily the thickness, of the completed plastic impregnated pipe. These formations are made continuously and may be directly inserted into a mold for casting, or they may be removed and preserved for future use in molds as desired.

It is, therefore, an object of this invention to provide a method of making tubular formations of randomly matted fibers.

It is a further object of this invention to provide amethod of forming such a fibrous formation with a light tacking of plastic material.

It is another object of this invention to provide'apparatus for forming tubular blanks of randomly matted fibrous material. I

It is still another object of this invention to provide apparatus for making tubular formations of randomly matted fibers having a light tacking of plastic material.

These and other objects of my invention will be fully understod from the following detailed description of typical preferred forms and applications of the invention,

throughout which description reference is made to the accompanying drawings in which:

Figure 1 is a schematic flow diagram of the process showing the relative location and arrangement of the various parts of the apparatus;

Figure 2 is an elevational view taken in section of a portion of a collection chamber and apparatus associated therewith;

Figure 3 is an elevational view taken in section of a further portion of the apparatus shown in Figure 2;

Figure 4 is an enlarged view taken in section along the lines 44 of Figure 5;

Figure 5 is a section taken along the line 5--5 of Figure 2;

Figure 6 is a section taken along line 66 of Figure 1, illustrating a modification of the invention;

Figure 7 is an elevational view taken in section of a modification of the collection chamber and associated apparatus;

Figure 8 is a section taken along line 88 of Figure 7; Y

1 Figure 9 is an elevational view taken in section of a modification of the face of the reciprocating ram; and

Figure 10 is a perspective view of a core or blank made in accordance with this invention.

Referring generally to Figure 1, a fiber storage container 10 is provided with a depending gravity feed dispenser 12 feeding a tumbler 14. The tumbler may be of any conventional design suitable for breaking up bundles of short fibers which are received from the dispenser 12, and may consist of a mechanically energized revolving chamber having interiorly disposed ribs or flukes as in awell-known cement mixer. The tumbler is supplied with a large mass of high velocity air from fan 16. The air may be preheated by heating unit 18 which may be constructed in any conventional and well-known design. The large volume of air speeding through the tumbler interior will pick up the individual short fibers, for example, glass fibers, and will carry them in a suspended state through conduit 20.

Disposed adjacent conduit 20 is a resin storage dispenser 22 which is provided with suitable metering means forcontinuously distributing a small amount of resinous material, in either a liquid or powdered form, into the stream of air and suspended fibrous material passing through the conduit. This material will be further de scribed hereinbelow.

The conduit 20 leads to the compactor collector hood 26, which is a cone-shaped hood designed to funnel the fiber-laden air stream delivered to its periphery through its apex 24. The conical construction of the hood, to gether with the peripherally-disposed entrance of the fiber-laden air stream, will create a whirling or cyclonic action of the air within the hood and will thus create a radial placement of the fibers in the collection chamber, as Will be discussed hereinafter.

Y Referring more particularly to Figure 2, the apex 24 of the conical hood 26 communicates with an annular collection chamber 30 which is formed by an exterior tubular wall 32 and an interiorly-disposed hollow mandrel defining an inner wall 34. As shown in Figures 2 and '3, the mandrel, indicated generally at 36, comprises an extended tubular structure, the structural details of which will be discussed hereinafter.

Referring especially to Figure 2, the mandrel 36 is securely fixed to and cantilevered from upstanding structural member 37, which is securely fixed to the base, or foundation, of the compactor machine. The mandrel may also receive some support from upstanding structural member 33, fixed to the base or foundation of the machine, which supports sleeve 41 surrounding the mandrel, and ram 40, as will be discussed hereinafter. The mandrel extends beyond the mouth or first end of the collection chamber 30, as defined by the outer wall 32, for substantial distance and has its interior in communication withan evacuating means, which may be the intake 17 of fan 16 (Fig. l) or any other suitable evacuating means. The walls of the mandrel, that is, the inner walls of the collection chamber, are provided with apertures substantially over the entire circumference thereof, these apertures having fine mesh replaceable screens 38 disposed therein. The provision of such large apertures in the wall 34 of the mandrel may serve to weaken the cantilevered structure, so the remaining portions of the mandrel wall may be built up or thickened to form support beams 39 having sufficient strength to support the weight of the free end of the mandrel. The operation of the evacuating means in communication with the interior of the mandrel will create a partial vacuum effect at the screened mouth of these apertures, and it will be seen that the stream of air entering the conical hood 26 will effect a whirling motion in ever-diminishing circles until its exits the hood and enters into the collection chamber. The suction applied to the surface of the screen will draw the air into the mandrel, from which it is removed by the evacuating mechanism, leaving the short fibers and the plastic impregnating material from dispenser 22 (-Figure 1) arrayed on the surface of the mandrel. or, more particularly, on or about the screens which act as retaining strainers. The continued straining effect will rapidly build up a substantial layer of fibers and plastic material on the exterior peripheral surface of the mandrel. This layer of fibers will, of course, conform to the tubular shape of the collection chamber which, for example, may be round, and will thus form the initial annular matted formation. Due to the whirling effect of the air passing through the collection chamber the fibers will be randomly oriented when they come to rest upon the screen 38. However, while these fibers will be randomly oriented, only a negligible number of fibers will come to rest in a radially extending position.

Slidably disposed upon the mandrel is a tubular ram 40 which is adapted to be reciprocated axially along the mandrel by electrically energized prime mover 42. The free end of the ram is provided with pivoted connecting arms 44 which are in turn pivotally mounted upon the crank shaft 46 which is mechanically engaged to the motor 42 by any suitable means, such as the belt and pulley arrangement shown generally at 48. The crank may be off center, that is, its axis at bearings 47 may be below or above the path of travel of the ram 40, the choice depending upon the selected directional rotation of the crankshaft, the arrangement being such that the ram will have a prolonged period of forward motion and a shortenedperiod of retracting motion. The effect of this arrangement will be that the ramming action will be considerably slower than the relatively rapid withdrawal or retractional movement. The face of the ram 40 comprises a pliable sleeve slidably disposed on the mandrel and has an exterior diameter slightly smaller than the interior diameter of the outer wall 32 of the collection chamber. During a portion of its reciprocating period, it will slide into the collection chamber for a substantial distance, and, during another portion of its reciprocating period, it will be withdrawn clear of the mouth of the chamber as indicated by arrow 43.

When the ram moves axially into the collection chamber, it will compress and pack the randomly-matted fibers which have collected on its surface adjacent the screens.- This compression will form amuch denserfibrous formation which will be forced to conform exactly with the predetermined shape of an annular collector chamber.

Each stroke of the ram will not only compress the fibers collected within the collection chamber, but will move the matted formation toward the exit or second end of the chamber. As this apparatus is operated con tinuously, the ram effects a continuous, though periodic, ejection of a compacted mat from this end of the collection chamber. short fibers, the mats will have a tendency to expand or slip back into the collection chamber upon removal of the pressure of the ram 'when it moves back for a new stroke. Therefore, the outer wall 32 is provided with a Due to the natural resiliency of the plurality of depending uni-directional stop dogs 50, which may be spring-biased to project into the end of the collection chamber and thus engage and prevent any re-expansion of the compacted fibers.

Referring to Figures 2, 3, and 4, the collection chamber exits into a congruent and coaxial heating chamber 52 which is defined by the enclosing of the exterior wall 32 with a steam chest 54. The steam chest is provided with entrance ports 56 for the introduction of live steam, hot water, or some other heating medium, as may be appropriate. The mandrel 36 is provided with an interiorlydisposed plug 58 which further defines the location of the heating chamber 52. The hollow mandrel acts as an evacuating air conduit, as discussed hereinbefore, but a Small portion of its interior is utilized to carry steam entrance pipe 60 and steam exit pipe 62, which extend through the evacuating air portions of the mandrel, through the plug, and into the heating portion of the mandrel 64. t The heating area of the mandrel is terminated adjacent the end of the heating chest 54 by interiorly-disposed plug 60'.

The outer wall 32 and inner walls 34 continue to form a precooling area which may be of any suitable length, and then enter a portion of the apparatus utilized as a cooling or chilling area. This area or portion 63 of the annular passage is defined by a peripheral cooling chest 65 surrounding the outer wall 32. A supply of compressed, air is introduced into the chilling chest through apertures 66 whichmay be arranged in communication with any suitable compressed air-supplying means. The portion of the outer wall 32 circumscribed by the cooling chest 65 is perforated (at 68) as is the exterior wall of the mandrel, thatis, the inner wall of the passage (at 70). The free end 72 of the mandrel 36 is provided with large apertures 73 allowing the free exhaust of the compressed air through the end of the tubular fibrous formation (not shown).

The periodic reciprocation of the ram compacts the fiber in the collection chamber and slowly forces the tubular formation through the annular passage 30, 52, and 63.

As the matted core or blank passes through the heating.

area 52 defined by the steam heating chambers, the thermosetting resin previously introduced into the fibrous material will react to form a light tack or binder which will be distributed through the fibrous mass. Further movement of the blank or core through the precooling and thence the chilling area 63 will permanently set such a plastic material so that the blank is permanently formed ina semi-rigid tubular shape, as shown in Figure 10.

As the blank is extruded from the end of the chilling area 63, it may be cut off into suitable lengths (by means not shown). As hereinabove mentioned, one use of such blanks or cores is as reinforcing lines for centrifugally-cast plastic" pipe as defined, for example, in the copending application of Lewis Perrault, Serial No. 391,821.

Referring to Figure 6, there is shown a modification of the invention in which the beams 39 converge slightly to define a circle having a diameter somewhat smaller than that of the mandrel wall 34. Each beam carries radiallyprojecting pins 75. In this modification the air-straining means comprises a tubular sleeve of fine mesh screening material which encompasses the beams 39 and pins 75, and which may be fixed to the latter by suitable bolts or other detent means. This tubular sleeve will have a diameter equal to or somewhat smaller than that of the exterior wall 34 of the mandrel 36. The effect of this arrangement will -be that the entire circumference of this portion of the mandrel, excluding the negligible area of the heads of the bolts, will define an air-straining surface.

Referring 'toFigures 7 and 8, I have shown a modification-of the invention in which the air strainer is placed on the outer periphery of 'the collection chamber 30. In such a case, the fine mesh screens 74 will be disposed within apertures in the outer wall 32. The screened area is provided with a circumscribing hood 76 which is placed '5 in communication with evacuating mechanism as describedhereinabove.

In Figures 7 and 9, there is shown a modificationof the ram 40. The free end of the sleeve of the compactor ram 40 may have an irregular face with lugs or knobs 78 projecting therefrom. Such knobs apparently have a circumferental packing eifect on those fibers immediately adjacent the face of the ram, tending to prevent slippage of loose fibers on the end of the matted formation. Moreover, this arrangement permits the quantities of fibers picked up by each pass of the ram to be interengaged with those already compacted into the tubular formation.

Referring to Figure 1, it should be noted that the dispenser 22 is arranged to dispense a very small amount of the thermo-setting material into the stream of air and suspended fibrous material passing through conduit 20. This resin is utilized to tack together some of the individual fibers forming-the finishedfibrous core or blank. It is well known that the expression tacking connotates a light adhesive effect, and it is not intended that the fibers be saturated or impregnated with the plastic material. This tacking operation only uses enough of the thermo-setting material to lend some rigidity to the core or blank, as it is a purpose of this invention to form a liner which may be thereafter submitted to a saturating or completely impregnating bath of plastic material to form the finished plastic pipe. It has also been determined that, unless the tacking material is used rather sparingly, the tacking material may serve to impede the subsequent saturation or impregnation of the liner when it is being utilized in the process of making plastic pipe as discussed hereinabove.

While reference has been made to short fibers, it is with the contemplation of this invention to use longer fibers when circumstances so dictate. It has been found that spun glass fibers make a particularly suitable reinforcing material, but the invention should not be restricted to fibers of any particular composition.

:Having described only a typical preferred form and application of the invention, it is not to be limited or restricted to specific detail-s herein set forth, but I wish to reserve to myself any variations or modifications that may appear to those skilled in the art and falling within the scope of the following claims.

I claim:

1. Apparatus for making an elongated annular formation of randomly matted fibres comrising an elongated annular collection chamber, means for whirlingly introducing a supply of fibrous material suspended in an air stream into said collection chamber, said collection chamber having a first open end to receive the air and the fibrous material, strainer means forming a portion of the structure of said collection chamber, and evacuation means juxtaposed to said collection chamber in communication with said strainer means, the arrangement being such that the fibrous material is collected against the strainer means, and ram means disposed for axial movement into said first end of said collection chamber for removing collected fibrous material from the strainer means.

2. The apparatus defined in claim 1, a second open end of said collection chamber, means for introducing a tacking resinous material into said supply of air and fibrous material, and fibrous formation heating means come municating with a second end.

3. In the apparatus defined in claim 2, fibrous formation cooling means communicating with said heating means.

4. Apparatus as defined in claim 1, wherein said collection chamber is formed by an exterior wall and an interior wall, said interior wall extending beyond the first end of said chamber, said ram means comprising a sleeve slidably disposed about said interior wall, said ram means being eccentrically engaged with rotational means, whereby said sleeve spends a relativelysmall por tion of each cycle within said collection chamber.

5..In the apparatus defined in claim 1, said collection chamber comprising an exterior wall, and an inner wall extending beyond the first end'of said collection chamber, said strainer means forming a portion of the said inner wall of said collection chamber.

6. In the apparatus defined in claim 1, said collection chamber comprising an exterior wall, and an inner wall extending beyond the first end of said collection chamber, said strainer means forming a portion of the said exterior wall of said collection chamber.

7. In the apparatus defined in claim 4, a second open end of said chamber, unidirectional stop means depending into said collection chamber between a second end and said strainer means to prevent re-expansion of the formation of fibrous material compressed by said ram' means. v

8. The process of making annular fibrous formations comprising suspending fibrous material in an air stream, whirlingly delivering said stream to a collection chamber, straining said stream through a forming strainer, compacting said material within a forming mold, and extruding the compactedmaterial from said mold.

9. A process of making annular fibrous formations comprising suspending fibrous material in an air stream, dispensing a resinous material into said air stream, whirlingly delivering said stream into a collection chamber, straining said stream through a forming strainer, compacting said fibrous material and said resin retained by the strainer within a forming mold, heating said compacted material while it is enclosed in said mold, cooling said material while still confined within said mold and extruding said material from said mold.

10. The process for making annular fibrous formations comprising suspending fibrous material in an air stream, dispensing a resinous thermosetting material into said air stream, delivering said stream to an annular collection chamber, straining said stream through inte- Iiorly disposed forming strainers compacting the material retained by said strainers within an annular forming mold, periodically conveying said material through a steam heated portion of said mold, periodically conveying said material through an air cooled portion of said mold, and periodically extruding said material from said mold.

11. The process of forming an annular fibrous formation comprising whirlingly depositing fibrous material and thermosetting resinous material in a collection chamber, collecting said material by the application of vacuum to foraminous strainers forming a portion of the collection chamber, compacting the fibrous material retained by the strainers and resinous material within an annular mold, forcing said material through a heated portion of said mold, forcing said material through a chilled portion of said mold and extruding said material from said mold.

12. Apparatus for making a substantially continuous elongated annular formation of randomly matter fibres comprising an elongated annular collection chamber, strainer means forming a portion of the structure of said collection chamber, evacuation means juxtaposed to said chamber in communication with said strainer means, and means for whirlingly introducing a supply of fibrous material suspended in an air stream into said chamber, said last-mentioned means comprising fan means, tumbler means, and vortex conduit means, said collection chamber having a first end open to said vortex conduit means to receive the whirling air and fibrous material, and ram means disposed for periodical axial movement into said first end of said collection chamber for compressing and removing fibrous material collected against said strainer means.

13. Apparatus defined in claim 12 wherein said collection chamber is formed by an exterior wall and an interior wall, said interior wall extending beyond the first end o s id ch mh r sai am me c mp i ng a s e v slidably disposed about said interior wall said ram means b n o o t i al y a e wit ot t o a moa wh r y said ram p n r ati e y ma Po t o o each cycle within d o l tion ch mber In the pp atu de i Q c a m a un di e tional stop means depending into said collection chamber between a second 1 5 @1 5 said t in mean to pr t ro-expansion t th o matio o vfibr u m te ia compressed by said ram means.

Apparatus for aking a substantial y co ou elongated annular formation of randomly matted fibers co p i an 9n a s chamber JnQ o w l y duc n sup y o fibrous mat r a su pended in an air-st eam int o 99.2 of sai o le t o chamber in a direction generally axially thereto, fixed strainer means forming a portion of the structure of said collection chamber, evacuation rclef ms J'UK BPQSed to said collection chamber in communication with saidofitrainer means, the arrangement being such that the ,fibrousrna' terial is collected against the strainer means, andjmeans for removing theannular formation ,formed in said annutar col ectio cham e om ,a secon .c d h r o .by causing mpvementgf the formation in adirection axially t e et an aw y rom th fi st end .o v a d ll ct on v hamoor.

Refigrences Cited in the .file of this patent UNITED STATES PATENTS 2443,54? Edmond s V.. Jan. 10, 1939 2,386,796 Hotfecker Oct. 16, 1945 2 5 9 8 Hi a t p 1 1 PH -V-- 2,609,312 Farrell Sept. 2 19 52 2,633,605 Brucker Apr.{7, 1953 2,702,261 7 Bacon Feb. 15, 19,55

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