US3446684A - Method and apparatus for forming tubular fibrous insulating articles - Google Patents

Description

3,446,684 ULAR FIBROUS May 27, 1 D. B. PALL ET METHOD AND APPARATUS FDR FORMING TUB INSULATING ARTICLES Sheet Filed March 24, 1965 QWJVJJTORS 3,446,684 ROUS May 27, 1969 D. B. PALL ET AL METHOD AND APPARATUS FOR FORMING TUBULAR FIB INSULATING ARTICLES Sheet Filed March 24, 1965 ATTORNEY;

May 27, 3, FALL ET AL 3,446,684 METHOD AND APPARATUS FOR FORMING TUBULAR FIBROUS INSULATING ARTICLES Sheet Filed March 24., 1965 lnlilhf N u-hivlf r Am I F hzHI NHhH U r l ung H u INV TOR-S A 531 A {5 ATTORNEYS g). B. PALL ET AL May 27, 1969 3,446,684 ous METHOD AND APPA ATUS FOR FORMING TUBULAR FIBR INSULATING ARTICLES Filed March 24 Sheet May 27, 1969 FALL ET AL 3,446,684

METHOD AND APPARATUS FOR FORMING TUBULAR FIBROUS INSULATING ARTICLES Sheet Filed March 24 .ATTORNEYJ 3,446,684 IBROUS May 27, 1969 D. B. PALL ET AL METHOD AND APPARATUS FOR FORMING TUBULAR F INSULATI NG ART ICLES Sheet Filed March 24, 1965 QQQ A T ORNEYS 3,446,684 IBROUS May 27, 1969 3, FALL ETAL METHOD AND APPARATUS FOR FORMING TUBULAR F INSULATING ARTICLES Sheet 7 of 9 Filed March 24, 1965 ATTURNEY May 27, 1969 D 5 FALL ET AL $446,684

METHOD AND APPARATUS FOR FORMING TUBULAR FIBROUS Filed March 24, 1965 INSULA'i'lNG ARI'ILCLES Sheet 8 of9 Q n50 \INVEN 7 ,4 T TaRNE VS May 27, 1969 v 4 9 H 8 r N 6 o M 6 T 4 r AQU... A 30 t R e r "w R A L U B U N m T m E T R L A L G A m .P m B m a D m METHOD AND APPARATUS FOR FORMING Filed March 24, 1965 United States PatentOfice 3,446,684 METHOD AND APPARATUS FOR FORMING TUBU LAR FIBROUS INSULATING ARTICLES David B. Pall, Roslyn Estates, and Robert Earle Belfield, East 'Islip, N.Y., David J. Rosenberg, Mountaintop, Pa., and Arthur C. Vogel, Glen Cove, N.Y., assignors to Certain-Teed Saint Gobain Insulation Corporation, a corporation of Maryland Filed Mar. 24, 1965, Ser. No. 442,441

Int. Cl. B32b 31/00; B65h 81/00 US. Cl. 156-184 34 Claims ABSTRACT OF THE DISCLOSURE Equipmentand method for forming tubular fibrous insulation articles, including a mandrel, means for rotatively mounting the mandrel in a mandrel station in which fibrous blanket material incorporating a heat settable fiber binder-is fed from a supply source and is wrapped upon the mandrel and after a plurality of layers are applied, the wrapped material is severed from the supply source. The article is formed on the mandrel by means of an endless conveyor belt having a re-entrant loop surrounding a large part of the periphery of the mandrel, and heat to set the fiber binder is applied by passing heated gas through the mandrel and radially outwardly through the mandrel perforations and thence through the fibrous' material, and also by heating the conveyor belt.

I Field ofinvention and statement of general objects and advantages This invention relates to production of tubes of fibrous insulating material and the invention is especially concerned with the production of such tubes or tubular articles from mineral fibers, for example glass fibers. Moreover,'the invention is particularly concerned with the production of articles of the'kind mentioned in which a large percentage of voids are present in the fibrous article, but in which the fibers are bound together by means of a binder-or adhesive, thereby consolidating the fiber structure and contributing substantial strength thereto, notwithstanding the presence of a high percentage of voids. u

The invention is concerned with improvement in the strength and insulating characteristics of fibrous tubular articles, such as insulating sleeves used for thermal insulation purposes, for instance by being applied exteriorly to pipes or piping carrying fluids with reference to which itis desired to reduce heat transfer.

The invention also has in view improved apparatus and production methods applicable to the manufacture of tubes of fibrous insulating material. In general, the method and equipment arranged according to the present invention provides for much more rapid production of tubular articles than has been practicable heretofore, and further provides for the production of tubes of insulating material of a wide variety of sizes, both with respect to inside. dimension, as well as with respect to tube wall thickness.

In considering certain additional objects and advantages, it is first to be noted that in accordance with the preferred production technique of the invention, the mineral'fibers (for example glass) are initially prepared in the form of a blanket or continuous web incorporating the fibers in random orientation. The blanket of fibers to be employed preferably also incorporates a heat settable or heat hardenablebinder or adhesive, for instance a binder incorporating a thermosetting resin. The blanket or web of fibers is then wound or rolled upon a mandrel,

. at the outer surface of Patented May 27, 1969 a multiplicity of layers preferably being applied, in order to shape the tubular article to be made. Thereafter heat is applied to the shaped article in order to set the binder and consolidate the article.

While it has been proposed heretofore to shape a tube of insulating material by winding it upon a mandrel and thereafter setting a binder therein by applying heat, the winding and setting operations have heretofore been effected at different stations, either by moving a series of mandrels from a winding station to a heating station, or by removing the article from the mandrel after winding and then placing the article in an oven. In contrast to this, the present invention provides for effecting the binder setting operation at the same station as the winding and while the article remains on the mandrel upon which it was initially wound to give it shape. This aspect of the invention is of advantage in increasing production rate with given equipment, because it is no longer necessary to handle the articles being made at a point in the production thereof between the winding operation and the binder setting operation. Moreover, only a single mandrel is needed in order to make articles of a given inside diameter. Still further, since the articles are not moved from station to station, there is no opportunity for damage to the articles.

In accordance with still another aspect of the invention, equipment is provided adapted to receive a roll of binder impregnated blanket material having a web of sheet material such as paper rolled therewith, the equipment being arranged to successively unwind fractional portions of the roll and successively wind up the portions of the fiber blanket on a mandrel on which the binder is cured, the Web of sheet material also being wound up independently.

In this way equipment is provided by which a series of tubular fibrous articles are produced from rolls of fibrous blanket (with intervening sheet material wound therewith) without the necessity for separately handling the blanket material which, of course, is relatively delicate or frangible, especially prior to the setting of the binder.

Still another aspect of the invention relates to the equipment and method employed for curing of the shaped tubular article, provision being made for penetration of a heating gas into the tube wall from the interior thereof and also for the development of a cured layer or skin the tube. This provides for uni formity of curing or setting of the binder within thetube wall and also for a well cured shell at the surface. of the article, both of which factors are of importance, especially with tubular articles having a relatively thick wall.

With further reference to the setting of the binder, the invention provides for effecting substantially uniform cur? ing of the binder throughout the thickness of the tube wall and without subjecting either the interior of the tube wall or the exterior surface thereof to excessive heat, such as tends to overcure the resin and even to damage the fibers. As will be explained more full hereinafter, this is accomplished by employment of a perforated mandrel and also of a perforated element surrounding theouter wall of the tube, and by maintaining the mandrel at a temperature below the temperature of the heating gases which are passed through the perforations of the mandrel for the purpose of setting the binder.

In connection with the feature just mentioned, it is also of advantage in accordance with the present inven tion that the binder of the tubular article is heated to effect setting thereof while the article is retained in confinement between the mandrel and an external surround; ing element, which takes the form of a perforated belt, as will further appear. This provides for maintenance of more accurate wall thickness than is practicable where an external element surrounding the article is not present during the heating to set the binder.

Brief description of figures How the foregoing objects and advantages are attained, together with others which will occur to those skilled in the art will be clear from the following description referring to the accompanying drawings, which illustrate two embodiments of equipment according to the invention and in which:

First embodiment FIGURE 1 is a side elevational view of one form of apparatus according to the invention, for receiving and winding up fibrous blanket material to form a tubular article and for heating the material to set the binder thereof;

FIGURE 2 is a view similar to FIGURE 1 but illustrating certain parts of the equipment in different positions;

FIGURE 3 is a front elevational view, taken from the right of FIGURE 1, but with a mid-portion broken out;

FIGURE 4 is an enlarged fragmentary view of portions of a mandrel on which fiber blanket is adapted to be wound, a portion of an article also being shown;

Second embodiment FIGURE 5 is a side elevational view of a second embodiment of equipment according to the invention, this embodiment being adapted to receive rolls of fiber blanket and being adapted to successively unroll fractional portions of the rolls delivered to the machine and to form and cure individual tubular articles from such successive portions of the blanket roll;

FIGURE 6 is a top plan view of the equipment shown in FIGURE 5 FIGURE 7 is a front elevational view on an enlarged scale, taken from the left of FIGURE 5;

FIGURE 8 is a vertical sectional view taken substantially as indicated by the line 8-8 on FIGURE 7, and showing the equipment in condition just preceding the commencement of an operation for winding a piece of fiber blanket on the forming mandrel;

FIGURE 9 is a view of certain parts shown in FIGURE 8 but illustrating various of the parts in the positions occupied during the curing or heating of an article on the mandrel;

FIGURE 10 is a fragmentary view illustrating a mandrel clamping arrangement to be further described;

FIGURE 11 is a further enlarged view fragmentarily illustrating certain parts of the mechanism taken as indicated by the section line 1111 on FIGURE 12 including the arrangement for mounting and driving the mandrel and various other parts to be described;

FIGURE 12 is an elevational view of various parts shown in FIGURE 11, FIGURE 12 being taken from the right of FIGURE 11; and

FIGURE 13 is a vertical sectional view taken substantially as indicated by the section line 13--13 on FIG- URE 12.

Brief statement of certan arrangements common to both embodiments In both of the embodiments to be specifically described hereinafter, a mandrel is employed which is hollow and has a perforate wall, the fibrous blanket being wound upon the mandrel so as to shape the article being made. In addition, in both embodiments an endless belt formed of foraminous material, such as perforated sheet material or metal mesh, is provided with guide means shiftable between two positions. In one position the belt is separated from the mandrel and in the other position a. reentrant run of the belt surrounds most of the periphery of the mandrel.

In both embodiments the article preferably is formed by winding a multiplicity of layers of fibrous blanket upon the mandrel and the layers are interfelted by virtue of rotation of the mandrel and of the surrounding run of the belt; and in both embodiments heating gases are delivered to the interior of the mandrel to flow through the perforations thereof into the article being formed, and in addition heat is applied to the outside surface of the article by means of the perforated surrounding belt, the internal and external heating cooperating to effect curing or setting of the binder and thus consolidation of the article.

Description of the first embodiment Referring to FIGURES 1 to 4 inclusive, the machine there shown is built up on frame members indicated at 14 which are interconnected with transverse structural tubes 14a. Toward one side of the machine (the right hand side as viewed in FIGURE 3) the frame members support two sets of rollers or discs 15 which cooperate to rotatively mount the sleeve 16 which is adapted to be driven by a motor 17 through a reduction gear unit 18 and a sprocket and chain drive 19.

The rotative sleeve 16 comprises a rotative support for the mandrel 20.

Advantageously as shown in FIGURE 3 the mandrel 20 is adapted to be removably mounted upon the left hand end of the support 16, a removable fastening bolt 21 being provided for this purpose, and it is contemplated that any of a plurality of different sized mandrels may be alternatively mounted upon the supporting shaft or sleeve 16.

As illustrated in the drawings, the mandrel is provided with a multiplicity of performations or apertures 22 and in addition the left hand end portion of the supporting sleeve 16 is also perforated as indicated at 23. The interior of the shaft 16 is hollow and is adapted to be connected to a hot gas supply pipe 24 (at the right of FIG- URE 3) through a rotati-ve seal or joint 25, so that the support 16 and the mandrel carried thereby may be freely driven by the drive chain 19 while being supplied with hot gases from the stationary or nonrotative supply pipe 24.

The employment of a multiplicity of apertures 23 in the mandrel support and also the employment of a multiplicity of apertures 22 in the mandrel itself both aid in securing uniform distribution of heating gases both lengthwise and circumferentially of the mandrel and thus both lengthwise and circumferentially of the article being formed on the mandrel.

As best seen in FIGURES l and 2, an endless belt 26 which is mounted in part by means of supporting rollers 27 and 28 which are movably carried, respectively upon pairs of pivoted arms 2929 and 30-30. The pair of arms 29 project from the sleeve 31 (see FIGURE 3) which is carried by the transverse shaft 32, so that the arms 29 may move together about the axis of shaft 32 between the position shown in FIGURE 1 and the position shown in FIGURE 2. Similarly the arms 30 project from sleeve 33 which is carried between transverse shaft 34, providing for conjoint movement of arms 30 between the position shown in FIGURE 1 and the position shown in FIGURE 2.

To insure conjoint pivotal movement of the pairs of arms toward and away from each other between the positions shown in FIGURES l and 2, the shafts 32 and 34 carry eccentrics 35 and 36 which are connected by adjustable links 37 and 38 with the slide 39 which slides in a fixed guide block 40 secured to one of the frame members 14. This arrangement provides for conjoint movement of the pairs of arms 29 and 30 and the links 37 and 38 provide for adjustment to vary the throw of the arms. The slide 39 is adapted to be moved by a reversible motor 41 through a reduction gear 42 and the link 43.

The belt 26 also passes over certain additional guide rollers and through the nip between rolls 44 and 45 which serve to drive the belt. The roll 44 is driven by means of the motor 46 through a reducing unit 47 (see FIGURE 1 and lower right of FIGURE 3).

Referring particularly to FIGURE 3 it will further be seen that a gas supply pipe 48 extends parallel to the mandrel 20 somewhat below the mandrel and to one side, .the pipe being provided with one or more series of apertures 49 directed toward the mandrel (see FIGURES 1 and 2) and serving as a burner so as to heat the belt and surface layer of the article, the belt desirably having perforations or being made of metal mesh.

Operation of the first embodiment With the foregoing description of the principal parts of the equipment in mind, a typical operation of the equipment is now described as follows:

With the arms 29 and 30 open, as in FIGURE 1, a piece of fiber blanket, :for instance glass fiber blanket, as indicated at F is laid by hand over the belt 26 on the run thereof passing over the upper guide roll 27, with the leading end of the blanket extended to a point closely adjacent to the mandrel 20. The operator now actuates the mechanism (motor 41) to close the pivoted arms 29 and 30 to the positions indicated in FIGURE 2. This position may be adjustably set by means of the adjustable abutment screws 50. It will be seen that in the position of FIGURE 2, the belt 26 is wrapped most of the way around the mandrel 20, i.e., there is a reentrant loop or run of the belt surrounding most of the periphery of the mandrel. When the arms first close following the condition shown in FIGURE 1, the operator starts both the mandrel motor 17 and also the belt motor 44, the two motors desirably having a common control, as a result of which the piece of fiber blanket which had been laid upon the machine as in FIGURE 1 is drawn into the re-entrant loop and is wound in multiple layers upon the mandrel. This rotation of the mandrel and belt is continued for an interval so as to effect interfelting of the fibers of the several layers and thus consolidate and homogenize the structure of the article being made.

In a typical operation, it is contemplated that the fibers of the blanket will have been impregnated with a liquid heat settable fiber binder, for instance phenol formaldehyde resin, and upon wrapping of the piece of blanket on the mandrel to form a given article, hot gases are delivered from the pipe 24, which is suitably valved for this purpose, to the interior of the mandrel, to flow through the perforations in the mandrel and radially outwardly through the fibrous article thereon and thereby effect curing or setting of the binder.

Advantageously in the operation of the equipment as shown in FIGURES l to 4, the mandrel is driven at a relatively high rotative speed during the initial heating with the gases supplied through the interior of the mandrel, and thereafter the mandrel speed is reduced, and for this purpose the mandrel motor 17 is desirably of variable speed.

After the initial period of heat treatment at the relatively high speed, and desirably at the time when the speed is reduced, the gas burner 48-49 is turned up so as to effect heating of the article being formed by heating the belt 26 and also by exposure of the article through the perforations in the belt. The gas burner may be provided with a pilot and may be turned on only during the time desired for treatment, or alternatively, the gas burner may normally be adjusted to burn at a very low flame or level throughout the entire operating cycle, except for a limited period of treatment immediately following the reduction in mandrel speed. Valving in the gas supply line may be provided for this purpose.

After an interval of operation with the hot gases delivered into the article through the perforations in the mandrel and with the hot gases impinging upon the belt and article from the burner 48-49, the burner is then turned down and the gas supply to the mandrel turned off. The operator then opens the arms 29 and 30 so as to unwrap the belt 26 with reference to the mandrel and the formed article. The mandrel drive is stopped and the operator may then readily withdraw the formed article by sliding it endwise from the mandrel (toward the left as viewed in FIGURE 3).

The belt drive is so adjusted as to avoid surface slippage on the article, and after completion of an article, the belt drive is terminated, and will only be restarted after an operator or attendant has again placed a piece of fiber blanket F into initial feed position, as shown in FIGURE 1.

Referring to the mandrel itself, it will be noted from FIGURE 4 that the mandrel is provided with longitudinal grooves 51, the presence of which results in formation of corresponding longitudinal ridges on the inside surface of the article being formed. This arrangement is advantageous for several reasons. In the first place the presence of the grooves in the mandrel provides an interlock between the mandrel and the article being formed, so that the mandrel and the article will be assured of rotation in unison. The ridges formed on the inner surface of the article are also of advantage in use of the article, such ridges acting to compensate for slight variations in the diameter either of the articles or of the piping to which the insulation is to be applied. The ridges will readily be somewhat deformed, in the event the pipe to which the insulation is applied is of slightly larger diameter than that of a circle defined by the inner edges of the ridges.

Although the insulating pieces may readily be employed in unbroken tubular form for certain purposes, it is also practical, and for most purposes preferred, to slit the tubular articles axially along one side thereof, so that the insulating tube may be opened by deformation of the material at the opposite side and then slipped laterally over a pipe to be insulated. Depending upon the thickness and size of the insulating piece a groove may also be cut in the inner surface of the article opposite to the slitted side in order to reduce the thickness of material required to be deformed when the article is opened up to apply it to a pipe.

With articles shaped, interfelted and cured, in accordance with the present invention, the material of the insulating piece has unusual capability for deformation and subsequent return to its initial shape. This is of great importance and advantage because the articles are capable of withstanding much abuse.

With regard to the cycle of heating employed, several factors of importance are to be noted, as follows:

First, since the heat is applied to the fibrous material of the article being formed through perforations in an internal member (the mandrel) and through an external member (the belt), the setting of the binder in the fibers is effected while the article is accurately sized to predetermined dimensions. Moreover, since the heating gases delivered through the mandrel to the article are turned off during certain portions of the cycle, the mandrel has an opportunity to cool somewhat in between the treatment of successive articles. This is of importance because the mandrel surface in contact with the interior of the article is thus maintained at a temperature lower than that of the curing gases. This avoids overheating of the internal surface of the article and thus avoids severing or damage to the fibers or binder. Similarly, and for two reasons, the surrounding belt is maintained at a temperature lower than the heating gases applied to the external surface of the article being formed. The two reasons for this are-first, that the belt has a relatively large closed loop, most of the path of feed of which is remote from the region of the gas heater 4849, so that the belt is continuously being cooled before it comes into engagement with the piece on the mandrel. Second, the gas flame is preferably turned down during certain portions of the cycle of operation of the equipment, and this also provides opportunity for the metal of the belt to cool off. Moreover, no appreciable harm will result even if the belt temperature rises to a high value when passing the burner, because the mesh elements of the belt do not remain in a given position of contact with the article throughout the curing period. It will be seen therefore that both the inside and the outside surfaces of the article are subjected to heating through or by means of confining elements establishing the size of the piece and at least the inside one of which is maintained at a temperature appreciably lower than that of the heating gases and the external one of Which changes its points of contact with the article. This avoids overheating of the internal and external surfaces of the article, and thereby avoids tendency for scorching or damage to the binder or fibers at the inner and outer surfaces of the article, while at the same time providing a relatively rapid curing rate, because gases may be passed through the mandrel at a temperature higher than that of the mandrel surface in contact with the piece.

In considering another important factor involved in the heating or curing cycle, it is first pointed out that although the invention contemplates that the burner 4849 shall either be turned off or adjusted to a low value or so as not to apply any appreciable heat to the article during the initial portion of the curing cycle (when the mandrel and belt are running at a relatively high speed) with either low heat or no heat from the burner, this initial portion of the curing will be effected chiefly under the influence of the hot gas introduced through the mandrel. This provides for a relatively slow curing during the initial portion of the curing cycle which is also of importance in order to avoid overcuring or scorching of the inner surface of the article being formed. After the first phase of the curing, the temperature of the article may be raised, as by the turning on of the burner 48-49 and this will serve to complete the curing without however subjecting either surface of the article to excessive heating. By combining the effect of the initial low heat and subsequent high heat phases of the curing cycle, with the effect of applying the heating gases through a perforated mandrel maintained at a temperature below that of the heating gases, articles of exceptional quality are attained with reference to uniformity of curing throughout the thickness thereof, and without surface damage due to localized overheating.

It may also be mentioned that by dividing the heating cycle into the low temperature and the high temperature phases, and at the same time providing for rotation of the mandrel and the belt at a high rate during the low temperature phase and at a low rate during the high temperature phase, the rate of curing pieces is accelerated so that the production rate of articles from the machine is increased. In a typical operation for making a sleeve of four inches inside diameter and one inch thickness, the high speed of the mandrel may be of the order of 70 r.p.m., and the low speed of the mandrel may be of the order of 7 rpm.

Mandrels of a variety of sizes may 'be mounted in the equipment so as to produce tubular members of a variety of sizes. Adjustments may also be made to vary the thickness of the piece, for instance by adjusting the extent of closure of the arms carrying the guide rolls 27 and 28.

For articles of certain sizes it may be advantageous to provide for opening of arms 29 and 30 even wider than that shown in full lines in FIGURE 1. For example the links 37 and 38 may be adjusted to positions in which the guide rolls 27 and 28 will open to the positions indicated in dot and dash lines at 27a and 28a.

The specific temperatures to be employed for the heating gas delivered through the mandrel and also the amount of heat applied by the burner 4849 will depend upon several factors, especially the nature of the particular binder employed and also the rates of rotation of the mandrel in the high and the low speed phases of the curing cycle. Those temperatures would also vary according to the size of the piece being made, its thickness, etc.

Moreover, the nature of the binder may be varied according to purposes and uses to be met, and the invention is not specifically concerned with particular binders, or specific temperatures, or the like, but rather with relative values, e.g., a low temperature phase, followed by a high temperature phase, etc.

It is to be understood that in the equipment of FIG- URES 1 to 4, it is contemplated that the belt and the mandrel shall be driven at relative speeds such as to avoid any appreciable slippage or creepage of the belt with reference to the external peripheral surface of the article being formed.

Descritpion of the second embodiment Many of the important features and operating characteristics of the first embodiment described above are also present in the second embodiment which is illustrated in FIGURES 5 to 13 inclusive. The equipment of FIGURES 5 to 13 inclusive has additional operating features and advantages, notably a more fully automatic cycle of operation, eliminating for example the necessity for manual preparation of individual pieces of fiber blanket to be used, and for manual feed of such pieces to the machine.

In the second embodiment as in the first, the article is formedby wrapping fibrous blanket between a mandrel and a belt having a re-entrant run surrounding most of the circumference of the mandrel; and as in the first embodiment, the arrangement of the second embodiment contemplates curing of the article by passing a heating gas through apertures in the mandrel and also by applying heat to a perforated belt in contact with the exterior surface of the article. Various parts of the equipment provided for these purposes, however, differ in the second embodiment as compared with the first and have certain distinctive advantages as will be pointed out. In addition to the general features just mentioned, the second embodiment also includes a number of additional features and structural arrangements, as will be developed, particularly in connection with the feed of the blanket material to the mandrel.

The machine of the second embodiment is built up upon a number of structural elements including the three upright frame plates 52, 53 and 54, which are interbraced by means of transverse elements such as transverse rod 55 and the transverse tube 56, this portion of the supporting structure serving to mount the mandrel, the belt and various devices associated therewith. In addition a skeleton frame structure composed of uprights 57 and transverse braces 58 and 59 serves to carry the fiber blanket receiving and feeding mechanism later to be described.

In the second embodiment, the mandrel support (see FIGURES 7 and 11) comprises a tubular structure 60 which is mounted on the upright frame plates 52 and 53 by means of two sets of triangulated rollers 61 (see also FIGURE 12) similar to the rollers 15 of the first embodiment. The right hand end of the support 60 as viewed in FIGURES 7 and 11 is adapted to receive a fitting 62 centrally apertured to mount a mandrel such as that indicated at 63, it being here noted that the particular mandrel shown as mounted in the equipment of the figures illustrating the second embodiment is a mandrel of relatively small diameter for example of the order of one inch. It is here mentioned that the mandrel mounting sleeve is adapted to mount mandrels of a variety of sizes, for which purpose different sized fittings 62 may be employed,

The mandrel is hollow and provided with perforations 64 as in the first embodiment, and hot gasses are adapted to be fed into the mandrel for delivery radially to the article formed through the mandrel support 60, for which purpose the mandrel support 60 is coupled with a gas supply pipe through a rotative connection 66, the gas supply pipe being branched as at 67 and 68 (see FIG- 9 URES 6 and 8), the branches being provided with valves 69 and 70 for regulating the quantity of gases entering the respective branches from the supply lines 71 and 72. The valves 69 and 70 are equipped with solenoid operated control devices such as indicated at 1C and 1H later to be described.

The mandrel is adapted to be driven by a motor 73 (see FIGURE 11) which is provided with a sprocket and chain output indicated at 74 coupled with a speed reducing uni-t 75 the output shaft of which carries a spur gear 76 meshing with a gear 77 arranged externally of the sleeve 60. The mandrel drive motor 73 is advantageously of variable speed, and provided with appropriate speed control, so as to provide for rotation of the mandrel at different speeds as desired, and particularly for the purpose of providing an initial phase of operation at 'a relatively high speed, followed by a phase of operation at a lower speed, during the curing cycle.

-It may here be pointed out that the mounting of the mandrel support by means of rollers such as indicated at 61 in the second embodiment and also as indicated at 15 in the first embodiment provides a sturdy and accurate support for the mandrel and at the same time avoids certain difiiculties which might be encountered by the employment of more conventional bearings, having in mind the fact that the hotcuring gases for the mandrel are passed through the mandrel support requiring operation at quite high temperatures.

Turning now to the arrangement of the belt in the second embodiment, it will be seen that this belt is indicated at 78, the belt as in the first embodiment being made of foraminous material and preferably being composed of a metal mesh. As seen particularly in FIG- URES 7, 8 and 9, the belt 78 is carried by a number of roller elements or supports, including rollers 79, 80 and 81, with a threading path over roller 79 and between rollers 79 and 80 and thence under roller 80 to the nip between rollers 80 and 81, after which the belt passes in the region of the mandrel 63. With the parts in the position of FIGURE 8, the run of the belt in this region passes over the burner pipe 82, and thence over a guide 83 to travel downwardly therefrom in a loop rejoining the upward run approaching the roller 79.

Attention is now called to the fact that the guide 83 is mounted upon a pair of arms 84 which in turn are pivoted to swing arms 85 by pivots 86, the arms 84 being pivotally adjustable with respect to the swing arms by means of adjusting bolts 87 which cooperate with arouate slots in the swing arm. I

The two swing arms 85 are rigidly interconnected by the tube 88 and the swing arm structure as a unit is adapted to be angularly shifted between the position shown in FIGURE 8 and the position shown in FIGURE 9 by means of a swing arm mounting shaft 89 journalled in the frame plates 52 and 53, and by a pivot 89a pivoted in frame plate 54 as seen in FIGURES 6 and 7. When the swing arm assembly shifts from the position shown in FIGURE 8 to the position shown in FIGURE 9, it 'will be noted that the guide element 83 shifts over and above the mandrel 63 and is brought down to a position close to the mandrel, thereby causing the belt 78 to adopt a reentrant run encircling much of the mandrel periphery. At the same time another guide element 90 carried by the swing arms cooperates with the belt to establish a run thereof from the guide 83 over the guide 90 and thence downwardly to rejoin the upwardly extended run approaching the roller 79. The motion of the swing arm assembly is effected by means of the motor 91 which is coupled by a sprocket and chain drive 92 (see particularly FIGURE 11) with a speed reducing unit 93 the output of which is coupled with the swing arm mounting shaft 89. The motor 91 is advantageously a reversible motor so that it may be employed to both raise and lower the swing arm assembly between the positions shown in FIG- URES 8 and 9.

An adjustable guide or roller 94 (see FIGURES 8 and 9) is arranged to cooperate with the lower portion of the belt and to take up the slack therein when the parts are in the position as illustrated in FIGURE 9. For this purpose the guide 94 is mounted on a pair of vertically adjustable racks 95, the position of which may be regulated through pinions 96 mounted on a shaft 97 and adjustable by means of the handle 98 (FIGURE 7). A pointer 99 with a scale 100 may be employed to indicate the adjustment of the racks 95 and thus of the slack takeup guide roll 94.

Attention is now called to the fact that the belt rollers 79, 80 and 81 are journalled on mounting arms or plates 101 (see FIGURES 5, =8 and 9) and further that these plates project upwardly at opposite sides of the machine from a base or supporting plate 102. The base plate 102 is supportedupon a pair of screwjack devices including the threaded elements 103 which project downwardly from the plate 102 and are received in the housings 104 containing rotative threaded screwjack nuts adapted to be actuated by a drive shaft 105 (see FIGURES 7, 8 and 9), this drive shaft being coupled through a sprocket and chain connection 106 with a reversible motor 107 by means of which the nut elements of the screwjacks may be rotated and thereby provide for raising or lowering of the threaded elements 103, to raise and lower the parts carried thereby. The housings 104 of the screwjack devices are mounted upon a supporting structure 108 which interconnects the upper ends of the pair of upright brackets or plates 109, the lower ends of which are provided with separable blocks adapted to embrace the rigid mounting tube 56 of the frame structure of the machine. This arrangement provides for angular adjustment motion of all of the parts carried by upright bracket or plate members 109 about the transverse axis of the rigid mounting tube 56. This adjustment is adapted to be made by turnbuckle adjustment devices 110. As an aid in making this angular adjustment a pointer 108b (see FIGURES 5 and 7) is fixed to the framework to give a reading on a scale 1080 carried by the extension 108a of the screwjack supporting structure 108. It will now be seen upon comparison of FIGURES 8 and 9, that when the screwjack devices 1031-0 4 are adjusted, the rollers 7-9, 80 and 81 are carried upwardly and downwardly toward and away from the mandrel 63, in the upper position, the uppermost roller 81 serving to cooperate with the guide element 83 in establishing a deep re-entrant run of the belt surrounding most of the periphery of the mandrel. When mandrels of different sizes are used and when articles of different thickness are being made, the devices 110 are adjusted to shift the angular position of the supports 109 so that the belt roller 81 is brought into the desired position in relation to the mandrel when the screwjacks are actuated to raise the belt rollers 79, 80' and 81. Suitable adjustment of the guide 83 is also made in order to accommodate mandrels of different sizes.

Attention is now directed to the drive system provided for the belt 78. This system includes a motor 111 which is mounted by brackets (not shown) from the structure comprising the supporting plates 101 and the base member 102, the motor being coupled by means of a sprocket and chain connection 112 with a speed reducing unit 113 having an output shaft 114 (see FIGURES 6, 8 and 9). The output shaft 114 is connected by a sprocket and chain drive 115 with the shaft of belt roll 79 and also with the shaft of another roll 116 to be described herebelow. The shafts of rolls 79, 80 and 81 are intergeared so as to rotate together, and being retained in close proximity to each other, these rolls act as a drive system for the belt 78.

The belt drive motor 111 is also desirably of variable speed or provided with speed control means so that the belt may be operated at different speeds according to that desired in various phases of the cycle of operation.

Attention is now called to the fact that an overrunning clutch 76a is included in the mandrel drive (see FIG- URE 11) providing freedom for overrunning of the mandrel support 60 with respect to the output shaft of the speed reducer 75; and further that there is an overrunning clutch 115a (see FIGURE 6) between the chain drive 115 and the shaft for belt roll 79, providing freedom for overrunning of the belt with respect to its drive. These overrunning devices ensure that the fibrous material being wrapped upon the mandrel will not be damaged in consequence of positive drive of both belt and mandrel at speeds not properly corresponding to the circumferential speeds of the internal and external surfaces of the article. One may overrun the other and therefore not damage the article being made. These overrunning devices will also automatically compensate for build up of wall thickness of the article while the multiple turns of the blanket are being wound upon the mandrel.

As above noted, the sprocket and chain drive 115 serves not only to drive the belt roll 79 through the overrunning clutch 115a but also serves to drive the roll 116 through the overrunning clutch 116a (see FIG- URE 6). As seen in FIGURES 8 and 9, roll 116 comprises one of a pair of rolls 116-117 which serve to carry an endless belt 118. In turn the belt 118 cooperates with another belt 119 running on rolls 120, 121 and 122. The two belts 118 and 119 comprise a feed conveyor which serves to deliver fiber blanket from the supply conveyor indicated at 123 to the mandrel 63. Roll 117 for belt 118 is desirably mounted on pivoted arms acted upon by springs 124 to tension the belt 118. Similarly belt 119 is tensioned by means of the mounting of roll 122 on pivoted arms which are biased by springs 125. Belts 118 and 119 may be made of a variety of materials, but advantageously comprise metal mesh belts.

The supply conveyor 123 may also be made of a variety of materials, a canvas belt being satisfactory for this purpose. At one end the conveyor 123 rides upon a roll 126 which is mounted upon the bracket or plate members 101 and which is therefore movable with all the parts carried by those brackets, including the feed conveyor belts 118 and 119 and the belt rolls 79, 80 and 81. The other end of the conveyor 123 is mounted by means of a roll 127 (see FIGURES and 6) and roll 127 is provided with supports 128 which are pivotally connected with the frame elements 59 by means of pivots 129. The journals for the roll 127 may also move toward and away from the roll 126 at the opposite end in order to accommodate the motions of the roll 126, which must follow the other parts which are mounted upon the bracket members 101.

As seen in FIGURES 5 and 6, the fiber blanket supply portion of the equipment includes an endless conveyor belt 130 supported by a pair of rolls 131 and 132 having substantial slack so as to form a cradle on which a roll R of fibrous blanket material may be placed.

In accordance with the practice contemplated by the invention, the fiber blanket material is preferably impregnated with the desired fiber binder at an early stage in the manufacture of the blanket, and the fiber blanket impregnated with the uncured binder is then rolled with a web of sheet material, advantageously paper. Preferably the paper is one having a wax or waxy surface to which the binder of the blanket will not readily adhere. The blanket and paper are wound together to form a roll such as shown toward the top of FIGURE 5 incorporating a multiplicity of turns and preferably including a quantity of fiber blanket sufficient to form a multiplicity of the tubular insulating articles being made.

Such a roll is placed in the cradle formed by the upper run of the endless conveyor belt 130 being positioned so that the free end of the blanket and paper project toward the right when viewed as in FIGURE 5 and pass over the roll 131 and thence downwardly at the right hand side of the machine to the region of a roll 133 which comprises one of a pair of rolls 133134 for supporting still another endless conveyor belt 135 also provided with slack so as to form a cradle for receiving the roll ofthe paper which is adapted to be separated from the roll in the manner now to be described. The fiber blanket itself which is indicated at F is fed downwardly past the roll 133 and the paper P is fed under the roll 133 and under the lower run of the conveyor 135, around the roll 134 and thence again to the right above the upper run of the conveyor, where it is wound upon a floating shaft or mandrel 136. This mandrel 136 need not be driven in any positive manner but will serve to roll up the paper as the conveyor belt 135 is driven, thereby feeding the paper to the mandrel 136.

Drive mechanism for the conveyor belts and includes the following parts most of which are best shown in FIGURES 5 and 6, it being noted first that the belt drive motor 111 (see FIGURE 8) serves as a source of power for this purpose. The power takeoff shaft 114 of the speed reducer 113 is connected by a sprocket and chain drive 137 with the shaft of roll 126 for the conveyor 123, a controllable clutch 138 being included in this drive. The shaft of roll 126 is further connected by a sprocket and chain drive 139 with a countershaft 140 carried by an upright or standard 141. In turn shaft 140 is connected by a sprocket and chain'drive 142 with shaft 143, and power is taken from shaft 143 to drive the conveyors 130 and 135. Conveyor 130 receives power from shaft 143 by means of a sprocket and chain drive 144 which interconnects shaft 143 and the shaft of roll 132, an overrunning clutch 145 again being included in the drive system. The clutch 145 not only serves to couple the chain drive 144 with the roll 132 but also serves to couple the shaft 143 with the roll 131 through still another sprocket and chain drive 146.

Power for driving the belt 135 is taken from shaft 143 through another overrunning clutch 147 and delivered through a sprocket and chain drive 148 to the shaft of roll 134. The shaft of roll 134 is connected by a sprocket and chain drive 149 with the shaft for roll 133. In this way both supporting rolls for the conveyor 135 are driven, as is also true of both rolls for the conveyor 130.

In addition to the power drive provided for belts 130 and 135, provision is made for manual movement of either of these belts in order to simplify the initiation of an operation with a fresh roll of fiber blanket and paper. For this purpose a hand operable crank 150 is adapted to be temporarily mounted upon the shaft for roll 133, thereby providing for manual rotation of roll 133 and thus of the belt 135 and thereby for initiation of the rolling up of the paper strip upon the mandrel 136. Manual overrunning of the belt 135 with reference to the belt 130 is permitted by virtue of the interposition of the overrunning clutch 147 in the drive which is extended to the belt 135.

Either the same handle 150, or another similar one is adapted to be temporarily mounted upon the shaft 151 which is connected by a sprocket and chain drive 152 with the shaft carrying the roll 131 for the belt 130. Manual rotation of the shaft 151 and thus of the roll 131 will serve to manually advance the belt 130, which motion is permitted because of the interposition of the overrunning clutch 145 between the shaft 143 and the sprocket and chain drives 144 and 146.

In view of the arrangements just described, it is possible to manually initiate the unrolling of blanket and paper strip and to thread them into the machine, for instance, to thread the fiber blanket F to the position illustated in FIGURE 5, without the necessity of operating the controllable clutch 138 which is normally used to concurrently operate all three of the conveyor belts 130, 135 and 123.

As shown in FIGURES 5 to 9, mechanism for cutting off the fiber blanket after winding the desired length thereof on the mandrel 63 is provided and preferably comprises a series of spikes 153 arranged transversely of the feed of the blanket and mounted upon a bar-154 which is vertically reciprocable under the influence of the fluid pressure cylinder and piston device 155.

The action of this cut-ofli mechanism will be referred to again hereinafter, but it is here noted that upon penetration of the spikes 153 into the blanket, and concurrent cessation of the motion of the conveyor 123, the continued action of the feed conveyor belts 118 and 119 acts to tear off and sever the blanket in the region of the spikes and to do this in a manner tending to feather the trailing end of the piece of blanket being wound upon the mandrel, rather than provide a sharp trailing end, such as would be present as a result of the use of a shear. This is of advantage in avoiding a permanent axial mark on the tubular article being formed. Indeed, upon the interfelting action occurring as the layers of blanket are rolled between the mandrel and the surrounding belt, the trailing end of the outer layer of the blanket is, in effect, obliterated, so that no mark in the final article remains.

During the winding up of a piece of the blanket upon the mandrel 63, the free end of the mandrel is preferably supported by a tailstock 156 (see FIGURE The tailstock is mounted on a bracket 157 supported upon the main vertical frame plates 54 of the machine and is pivotally movable by means of links 158 and 159, the latter of which is in the form of a bell crank having an arm 160 adapted to be actuated by a fluid pressure piston and cylinder device 161. During the winding of an article upon the mandrel 63 the parts are positioned as in FIG- URE 10 and the tailstock is in engagement with the mandrel to rotatively support the free end thereof. After a piece has been wound the piston and cylinder device 161 is actuated to displace the tailstock 156 away from the end of the mandrel 63 and also to a side of the axis thereof, in order to provide clearance for the removal from the tubular article formed, the displaced position of the tailstock being shown in dot and dash lines at 156a in FIGURE 10.

The removal of an article is advantageously effected by means of a stripper mechanism including a stripper plate 162 (see particularly FIGURES 7, 8 and 11 to 13). This stripper plate is apertured to pass the mandrel and, when mandrels of different size are employed, it is contemplated that stripper plates of different shapes will be used. The stripper plate is mounted upon a shaft 163 which in effect comprises the piston rod projecting from one end of a cooperating fluid pressure cylinder 164, in which a piston (not shown) connected with the rod 163 is movable in either direction under the influence of pressure admitted to one end of the cylinder or the other. When an article has been formed and the tailstock opened, the stripper device is operated to move the stripper plate 162 outwardly along the mandrel (to the right as viewed in FIGURE 7), thereby pushing the formed piece off the free end of the mandrel. Advantageously, the stripper mechanism carries a means for applying a material to the surface of the mandrel adapted to avoid sticking of the article to the mandrel. A waxy or oily material may serve this purpose and may be applied to the mandrel by means of a brush 165 positioned just behind the stripper plate 162 and receiving the material to be applied to the mandrel in liquid form, for instance in the manner of a wick, the liquid supply reservoir being indicated in FIGURE 8 at 166 and the supply pipe at 167. The reservoir 166 and the supply pipe 167 may be mounted on the stationary bracket 168 in position (see FIGURES 7, 8, 11 and 12) so that each time the stripper returns to its inner position,

the pipe 167 will drip the mandrel coating liquid into a well 169 at the base of the brush 165.

Before considering the operation of the second embodiment it is noted that the gas burner pipe 82 is joined with downwardly extended supply pipe 82a (see FIG- URES 7 and 8) which is mounted for adjustment movement toward and away from the mandrel by means of the screw device 170. By this means the gas tube may be moved toward and away from the mandrel 63 in accordance with the size of the piece being made or the wall thickness thereof.

Operation of the second embodiment In a typical operation in the making of a series of articles, the following sequence of events will occur.

First, for the purpose of preparing the machine to produce the articles, a roll R of the fiber blanket F and paper P are placed in the cradle of the conveyor 130, and by hand, the blanket and paper are fed into the machine, the blanket being laid upon the conveyor 123 up to the position indicated in FIGURE 5 and the Winding of the paper is started upon the floating mandrel 136 cradled in the conveyor 135.

Now assume a starting condition in which the stripper 162 has returned to its inner position and the tailstock 156 has been shifted to support the free end of the mandrel 63 as shown in full lines in FIGURE 10. In addition assume that the cut-off spikes 153 have been raised, and that the base plate or carriage 102 and the parts supported thereby are in the lower position, for instance the position of those parts shown in FIGURE 8. Finally, assume that a small size mandrel such as shown in the drawings is being employed so as to produce an article having a relatively small inside diameter, of the order of one inch or less, with a wall thickness of about one inch. With the apparatus thus conditioned the conveyor motor 111 and mandrel motor 73 are started and the supply conveyor clutch 138 is engaged. The leading end of the fiber blanket F is now fed by the supply conveyor 123 into engagement with the feed conveyors 118119 and the mandrel 63, the belt 78 and feed conveyors 118-119 are rotated until the leading end of the fiber blanket reaches the position indicated at F in FIGURE 8. At this point the motors 111 and 73 are stopped, thereby stopping all of the conveyors as well as the mandrel and belt, and carriage motor 107 and swing motor 91 are started in the direction to raise the carriage from the position shown in FIGURE 8 to the position shown in FIGURE 9; and to swing the arms from the position shown in FIGURE 8 to the position shown in FIGURE 9. Upon attaining the position of FIGURE 9 the motors 107 and 91 are stopped and the motors 111 and 73 are again started, thereby reactivating the conveyor belts and effecting rotation of the mandrel. With a mandrel of small diameter, the cut-off spikes 153 may also be lowered at this time, as is shown in FIGURE 9, and the clutch 138 for the supply conveyors is disengaged. In consequence the conveyors 118 and 119 and the belt 78 and the mandrel 63 will cause feed -to the mandrel of the piece of fiber blanket extended from the spikes 153 to the point P, the piece being wrapped upon the mandrel in a plurality of layers.

It should here be noted that with a mandrel of larger diameter or where greater wall thickness is desired, or both, the cut-off spikes 153 would not be lowered until additional blanket material had passed that point, for which purpose the clutch 138 would of course also be retained in engagement for a longer interval of time. In any event, whether the disengagement of the clutch 138 and descent of the spikes 153 coincide in time with the restarting of the conveyors 118-119 and of the belt and mandrel, or whether the disengagement of the clutch 138 and the lowering of the spikes 153 occurs at an interval subsequent to the restarting of the feed conveyors 118-119, a piece of the blanket from the roll R is fed to the mandrel and wrapped thereon in a plurality of layers between the mandrel itself and the surrounding re-entrant run of the belt 78.

Preferably rotation of the mandrel and of the surrounding belt is continued for an appreciable interval after the piece of the fiber blanket is wound upon the mandrel, in order to subject the several layers on the mandrel to an interfelting action which, in effect, re-

15 sults in substantial consolidation of the fibers of the several layers, thereby making the article more homogeneous.

During the winding of the blanket on the mandrel and during the continued rotation of the piece on the mandrel following the winding, warm air is delivered through the mandrel from the pipe branches 67 and 68 and through the connection 65. Advantageously during this phase or stage of the operation a mixture of hot gases from the pipe 72 and of cool or room temperature air through the pipe 71 is delivered to the mandrel, this mixture being provided by appropriate adjustment of the solenoid controls 10 and 1H for the valves. Moreover some heating may be applied externally to the article being formed by operation of the burner 82 at a relatively low flame.

After an interval of operation under the conditions just described, the motors 111 and 73 are then operated at a lower speed, and the heating of the article being formed is intensified, both interiorly and exteriorly, by closing off some or all of the cool air supplied from the pipe 71 and by raising the burner or flame level of the burner 82. An interval of treatment at the lower speed and higher temperature is then maintained, after which the burner is again shut down, or adjusted to its low or pilot level, and the hot air from pipe 72 to the interior of the mandrel is diminished and the cool air from pipe 71 is increased. Substantially concurrently with this change in the temperature conditions, the motors 111 and 73 are stopped, so as to stop the conveyor system, the belt 78 and the mandrel. The motors 107 and 91 are then operated in the reverse direction so as to again lower the carriage 102 to the position in FIGURE 8 and also return the swing arms 85 from the position of FIGURE 9 to the position of FIGURE 8. With all of the conveyors, the mandrel and the belt at rest, the tailstock cylinder 161 is actuated to displace the tailstock 156 to the position shown at 156a in FIGURE 10, and thereafter the stripper 162 is operated to eject the completed, formed and cured article. After ejection of a formed article the stripper is returned to its inner position, which completes a cycle of operations or events which are then repeated in the manner already described.

Although the foregoing operations may be carried out in whole or in part manually, as by means of control buttons with or without the interposition of servo-mechanisms such as solenoids, it is contemplated that for most purposes, at least certain of the operations shall be effected automatically or triggered by others in order to simplify the manipulation of the equipment. For example note the following features which are advantageously included in the control system for the overall operation of v the machine. First note that as seen in FIGURE 7, when the stripper 162 returns to its inner position, it engages the operating element 171 of a microswitch 172 which may be employed to initiate operation of the motors 111 and 73 to start the feed of the fiber blanket for the next succeeding article to be formed. Either manual or timing means may be used to control the feed of the blanket to the position indicated at F in FIGURE 8, and such means may also be employed to initiate the raising of the carriage 102 and of the swing arms 85. When the swing arms approach their upper position as shown in FIGURE 8 the switch 173 (see FIGURE 13) operated by cam 174- car-ried by the swing arm shaft 89 may be employed to shut off the motor 91. Preferably the cam 174 is angularly adjustable about shaft 89, the adjusted position being indicated on a scale 175 so that the swing arm motion in the upper direction may be terminated at any desired point, depending upon the size of the mandrel being used and the thickness of the article to be made.

Similarly the upward motion of the carriage 102 (see FIGURES and 7) may be relied upon to operate the switch 176, this switch being supported by the bracket 177 which depends from a vertically movable part of the carriage, the switch being positioned so that when it rises with the carriage, the switch actuating element 178 engages an abutment 179 carried on the extension 108a of the screwjack supporting structure 108. The switch is adjustable in position with reference to the bracket 177 by means of a screw adjustment device 180, whereby the operation of the switch 176 to shut off the carriage lifting motor 107 may be adjusted to cause the carriage and thus the feed conveyors to rise to whatever extent is desired, depending upon the size of the mandrel and the thickness of the piece being made.

Restarting of the motors 111 and 73, and also initiation of the operation of the burner 82, as well as regulation of the valves 70 and 69 for controlling the hot and cool gases to be delivered to the interior of the mandrel may be accomplished by manual or timing means, as may also the reduction in speed of the mandrel and belt and the increase in the heat supplied by the burner 82 and through the mandrel.

In addition, the operation of the cut-off spikes 153 may be accomplished by manual or timing means, providing for cut off of the blanket at a point providing suflicient blanket to produce the article being made.

Proceeding to the next phase of the operation, upon stopping of the mandrel and belt, and turning down of the external and internal heat sources, either by manual or timing means, the carriage motor 107 and the swing arms motor 91 are reversely operated, either manually or by timing means. Preferably the swing arm motor is shut off by means of a switch 181 (see FIGURES 8 and 9) having an actuating element 182 which is engaged by the cross connecting tube 88 between the swing arms. Similarly, the downward motion of the carriage may be arrested by means of a switch 183 having an actuating element 184 adapted to engage the extension 108a of the screwjack supporting structure 108 (see FIGURES 5 and 7). After the swing arms and the carriage have both been lowered, the stripper element 162 is actuated either manually or by timer means. The return motion or return stroke of the stripper is adapted to be initiated by a switch 185 (see FIGURES 7, 8 and 11). The switch 185 advantageously comprises a proximity switch which is triggered by the piston connected with the piston rod 163 travelling in the cylinder 164. When the piston reaches a point adjacent to the switch 185 this switch is triggered by virtue of the proximity of the piston to operate the stripper actuating piston and cylinder in order to retract the stripper and again trip the switch 171, to start on a new cycle of operation, as described above.

Advantages From the foregoing description of the structure and operation of the two embodiments of apparatus disclosed, it will be noted that the two embodiments have numerous advantages in common, many of which are already mentioned above including the curing of the articles being made on the mandrel on which they are wound and shaped, thereby eliminating various handling operations heretofore resorted to. The curing of the articles while held between the mandrel and the surrounding belt also provides for accuracy and uniformity of shape and dimension of the pieces. The application of heat both internally and externally of the piece being made, and also the application of heat in two stages, the first of which is at a lower temperature than the second, also diminishes overcuring or scorching, with resultant damage to the articles.

The use of a perforated mandrel and also of a mandrel having longitudinal grooves therein is contemplated in both embodiments of the equipment although it appears only in FIGURE 4 relating to the first embodiment, and this is of advantage in avoiding slippage of the article being formed on the mandrel, as well as in providing longitudinal ridges on the interior of the article, with the accompanying product advantages already discussed.

The first embodiment is distinctly advantageous be- 17 cause of its relative simplicity and yet substantial capacity for production. In addition, in equipment according to the first embodiment a wide range of sizes may be made, it being practical to form articles by equipment according to the first embodiment running for example for an inside or mandrel diameter of about 2 or 3 inches, up to an inside or mandrel diameter of the order of 16 to 18 inches.

Although equipment constructed according to the second embodiment may not have the capability of producing articles of quite as broad a range of sizes as the first embodiment, nevertheless the equipment of the second embodiment is capable of producing articles of a smaller size than is practicable with equipment of the first embodiment. Thus a given machine constructed according to the equipment of the second embodiment may be employed to produce articles having inside diameter or mandrel size running from about 4 or 5 inches down to a diameter of the order of /2 inch.

The equipment of the second embodiment also readily lends itself to automatic and timer control with respect to at least many phases of its operation and for this reason is capable of very large output with a minimum of attendance.

We claim:

1. Equipment for forming tubular articles from a fiber blanket, including a mandrel, rotative mandrel mounting means establishing a mandrel station and providing for support of the mandrel from one end thereof with the other end of the mandrel free to provide for axial stripping of a formed article from the mandrel in said station, a closed loop travelling conveyor belt for the blanket, a guide for the belt movable between a position establishing a conveyor run lying toward a side of the mandrel mounted in said station and adapted to receive the leading end portion of the fiber blanket and a position in which the conveyor belt is wrapped partway around the mandrel and adapted to wrap the blanket around the mandrel in said station, and drive means for the mandrel and for the belt providing for wrapping of a plurality of layers of the blanket on the mandrel and for interfelting the fibers of the several layers on the mandrel.

2. Equipment for forming tubular articles from a fiber blanket incorporating a heat settable fiber binder, including a mandrel, rotative mandrel mounting means establishing a mandrel station and providing for support of the mandrel from one end thereof with the other end of the mandrel free to provide for axial stripping of a formed article from the mandrel in said station, a closed loop travelling conveyor belt for the blanket, a guide for the belt movable between a position establishing a conveyor run lying toward a side of the mandrel mounted in said station and adapted to receive the leading end portion of the fiber blanket and a position in which the conveyor belt is wrapped partway around the mandrel and adapted to wrap the blanket around the mandrel in said station, drive means for the mandrel and for the belt providing for wrapping of a plurality of layers of the blanket on the mandrel and for interfelting the fibers of the several layers on the mandrel, and means for heating the interfelted fibrous article on the mandrel in said station to set the binder and consolidate the article.

3. Equipment for forming tubular articles from a fiber blanket, including a mandrel, rotative mandrel mounting means establishing a mandrel station and providing for support of the mandrel from one end thereof with the other end of the mandrel free to provide for axial stripping of a formed article from the mandrel in said station, a closed loop travelling conveyor belt for the blanket, and a pair of guides for the belt movable with respect to the mandrel between a first position establishing a conveyor run at least a portion of which extends to one side of the mandrel mounted in said station to receive the leading end portion of the fiber blanket and a second position in which the conveyor run between the guides is wrapped most of the way around the mandrel but in which the second position the guides are spaced from each other sufficiently to admit additional blanket to the mandrel for wrapping multiple layers thereon while the conveyor run is wrapped around the mandrel in said station.

4. Equipment for forming tubular articles from a fiber blanket incorporating a heat settable fiber binder, including a mandrel, rotative mandrel mounting means establishing a mandrel station and providing for support of the mandrel from one end thereof with the other end of the mandrel free to provide for axial stripping of a formed article from the mandrel in said station, a perforate closed loop travelling conveyor belt for the blanket, a pair of guides for the belt movable with respect to the mandrel between a first position establishing a conveyor run at least a portion of which extends to one side of the mandrel mounted in said station to receive the leading end portion of the fiber blanket and a second position in which the conveyor run between the guides is wrapped most of the way around the mandrel but in which second position the guides are spaced from each other sulficiently to admit additional blanket to the mandrel for wrapping multiple layers thereon while the conveyor run is wrapped around the mandrel in said station, and means for heating the article externally and internally while it is rotating with the mandrel in said station to set the fiber binder and consolidate the article.

5. Equipment for forming tubular articles from a fiber blanket incorporating a heat settable fiber binder, including a mandrel, rotative mandrel mounting means establishing a mandrel station and providing for support of the mandrel from one end thereof with the other end of the mandrel free to provide for axial stripping of a formed article from the mandrel in said station, a closed loop travelling conveyor belt for the blanket, a pair of guides for the belt movable with respect to the mandrel between a first position establishing a conveyor run at least a portion of which extends to one side of the mandrel mounted in said station to receive the leading end portion of the fiber blanket and a second position in which the conveyor run between the guides is wrapped most of the way around the mandrel in said station, the mandrel and the belt being perforate, and means for passing heating gases through the perforations of the mandrel and for applying heat to the perforated belt to set the fiber binder and consolidate the tubular article formed.

6. Equipment for forming tubular articles from a fibrous blanket incorporating a heat settable fiber binder, including a rotative mandrel, a closed loop travelling conveyor belt for the blanket, means for wrapping the conveyor belt and the blanket around the mandrel to form a tubular fibrous article thereon, the mandrel being hollow and having a perforate wall, and conduit means including a rotative conduit joint for delivering heated gas to the interior of the mandrel to flow through the perforations thereof into the fibrous article while the mandrel is rotating.

7. Equipment as defined in claim 6 and further including rotative mounting means for the mandrel comprising a plurality of rollers angularly spaced from each other about the axis of the mandrel intermediate said rotative conduit joint and the opposite end of the mandrel.

8. Equipment for forming tubular articles from a fibrous blanket incorporating a heat settable fiber binder, including a rotative mandrel, a perforate closed loop travelling conveyor belt for the blanket, means for wrapping the conveyor belt and the blanket around the mandrel to form a tubular fibrous article thereon, and heating means adjacent the side wall of the fibrous article on the mandrel for curing the binder by applying heat to the perforated belt.

9. Equipment as defined in claim 8 in which the belt comprises metal mesh and in which the heating means comprises a burner for directing a flame against the mesh belt.

10. Equipment for forming tubular articles from a fibrous blanket incorporating a heat settable fiber binder, including a rotative mandrel, a closed loop travelling conveyor belt for the blanket, means for wrapping the conveyor belt and the blanket around the mandrel to form a tubular fibrous article thereon, the mandrel being hollow and having a perforate wall, means for delivering heated gas at a relatively high temperature to the interior of the mandrel when an article is wrapped thereon to flow through the perforations thereof into the fibrous article to effect curing of the binder, means providing for removal of a cured article from the mandrel, and means for delivering gas at a lower temperature to the interior of the mandrel after removal of an article therefrom to flow through the perforations of the mandrel and effect reduction in temperature thereof.

11. Equipment for forming tubular articles from a fibrous blanket incorporating a heat settable fiber binder, including a rotative mandrel, a closed loop travelling conveyor belt for the blanket, means for wrapping the coni veyor belt and the blanket around the mandrel to form a tubular fibrous article thereon, means for driving the belt and rotating the mandrel at one speed, means for flowing heating gas at one temperature through the fibrous article during rotation at said one speed, means for driving the belt and rotating the mandrel at a lower speed, and means for flowing heating gas at a higer temperature through the fibrous article during drive of the belt and rotation of the mandrel at said lower speed.

12. Equipment for forming tubular articles from a fibrous blanket incorporating a heat settable fiber binder, including a rotative mandrel, a closed loop travelling conveyor belt for the blanket, means for wrapping the conveyor belt and the blanket around the mandrel to form a tubular fibrous article thereon, the mandrel bein hollow and having a perforated wall, and mechanism for flowing gas into the interior of the mandrel and through the perforations into the fibrous article including a first conduit for supplying gas at one temperature, a second conduit for supplying gas at a higher temperature, and valve means for said conduits providing alternatively for delivery of gas predominantly from said second conduit for setting the fiber binder and for delivery of a lower temperature mixture of gases from both conduits for reducing the temperature of the mandrel.

13. Equipment for forming tubular articles from a fibrous blanket incorporating a heat settable fiber binder, including a mandrel, rotative mandrel mounting means establishing a mandrel station and providing for support of the mandrel from one end thereof with the other end of the mandrel free to provide for axial stripping of a formed article from the mandrel in said station, a closed loop travelling conveyor belt for the blanket having a re-entrant run wrapped partway around the mandrel and leaving a portion of the mandrel exposed to receive fibrous blanket to be wound on the mandrel, conveyor means for delivering fibrous blanket from a source of supply to the mandrel in the region of the exposed portion thereof, means for driving the belt and rotating the mandrel to wind the fibrous blanket on the mandrel, and means for heating the article on the mandrel while the mandrel is rotating in said station.

14. Equipment as defined in claim 13 in which the means for rotating the mandrel includes an overrunning clutch providing freedom for rotation of the mandrel under the influence of advancement of the belt.

15. Equipment as defined in claim 13 in which the means for driving the belt includes an overrunning clutch providing freedom for advancement of the belt under the influence of the rotation of the mandrel.

16. Equipment for forming tubular articles from a fibrous blanket, including a rotative mandrel, a closed loop travelling conveyor belt for the blanket having a re-entrant run wrapped partway around the mandrel and leaving a portion of mandrel e p s d o recei e fi rous blanket to be wound on the mandrel, conveyor means for delivering fibrous blanket from a source of supply to the mandrel in the region of the exposed portion thereof, means for driving the belt and rotating the mandrel to wind fibrous blanket on the mandrel, and blanket cut-off means operative to cut ofi the blanket after a plurality of layers have been wound on the mandrel.

17. Equipment as defined in claim 16 in which the blanket cut-off means comprises a plurality of spikes arranged in a series across the blanket and mounted for movement to penetrate the blanket and thereby cause tearing of the blanket under the influence of the delivery conveyor means.

18. Equipment for forming tubular articles from a fibrous blanket, including a rotative mandrel, a closed loop travelling conveyor belt for the blanket having a re-entrant run wrapped partway around the mandrel and leaving a portion of the mandrel exposed to receive fibrous blanket to be wound on the mandrel, a feed conveyor f r feeding fibrous blanket to the mandrel in the region of the exposed portion thereof, a supply conveyor for supplying fibrous blanket to the feed conveyor, blanket cut-01f means for cutting off the blanket in a zone in advance of the feed conveyor, and disconnectible means for driving the supply conveyor independently of the feed conveyor.

19. Equipment as defined in claim 18 and further including common driving means for the belt and feed conveyor.

20. Equipment for forming tubular articles from a fibrous blanket, including a rotative mandrel, a closed loop travelling conveyor belt for the blanket having a re-entrant run wrapped partway around the mandrel and leaving a portion of the mandrel exposed to receive fibrous blanket to be wound on the mandrel, means for supporting a supply of fibrous blanket incorporating a multiplicity of interconnected turns thereof, means for paying out the blanket from said turns, and conveyor means receiving the payed out blanket and delivering it to the mandrel.

21. Equipment for forming tubular articles from a fibrous blanket, including a rotative mandrel, mechanism for wrapping fibrous blanket on the mandrel, means for supporting a supply of fibrous blanket in a form having a web of sheet material at one side thereof and having a multiplicity of interconnected turns, means for paying out said turns, means for separating said web from the fibrous blanket, and conveyor means receiving the payed out fibrous blanket and delivering it to the mandrel.

22. Equipment as defined in claim 21 and further including means for separately rolling up the sheet material of said web.

23. Equipment for forming tubular articles from a fibrous blanket incorporating a heat settable fiber binder, including a mandrel support and a mandrel removably mounted thereby for rotation, the mandrel support having mandrel mounting means adapted alternatively to mount mandrels of different diameter for use in forming tubular articles of different diameter, mechanism for wrapping fibrous blanket around a mandrel mounted on the support to thereby form a tubular article, the support and the mandrel having interior hollows communicating with each other when the mandrel is mounted on the support, the mandrel when mounted on the support extending therefrom in one direction axially of the support and means for setting the fiber binder of a fibrous article formed on the mandrel including a supply conduit for a heating gas and a rotative joint between the gas supply conduit and the interior hollow of the mandrel support, the joint being located axially of the support at the end thereof opposite to the extension of the mandrel, the mandrel having a perforate side wall through which the heating gas is delivered into the tubular article formed on the mandrel.

24. Equipment for forming tubular articles from a fiber blanket, including a rotative mandrel, a closed 100p travelling conveyor belt for the blanket, a guide for the belt movable between a position establishing a conveyor run lying toward a side of the mandrel and adapted to receive the leading end portion of the fiber blanket and a position in which the conveyor belt is wrapped partway around the mandrel and adapted to wrap the blanket around the mandrel, a feed conveyor for delivering fibrous blanket to said run of the belt, and mounting means for the feed conveyor and the belt guide providing for conjoint movement thereof with respect to the mandrel.

25. Equipment as defined in claim 24 in which the belt guide comprises a rotative member and in which the feed conveyor includes a rotative mounting member, and further including common driving means for both of said rotative members.

26. Equipment as defined in claim 24 in which the mandrel is removable and replaceable by a mandrel of different diameter, and further including means for conjointly shifting the position of the belt guide and the feed conveyor with respect to the mandrel to accommodate mandrels of ditferent diameter.

27. Equipment for forming tubular articles from a fibrous blanket material incorporating a heat settable fiber binder, including a rotative mandrel on which the fibrous material is adapted to be wound, a closed loop travelling conveyor belt adapted to engage the fibrous blanket material on the mandrel, a guide for the belt, mounting means for the guide movable between a positio establishing a conveyor run lying toward a side of the mandrel and a position in which the conveyor belt is wrapped partway around the mandrel and adapted to engage the material wound on the mandrel and thus rotate the mandrel with the material wound thereon, and adjustable means for varying the relation of the guide to the mandrel and thus of the belt to the mandrel.

28. Equipment as defined in claim 27 in which the guide mounting means comprises a pivoted arm.

29. Equipment as defined in claim 28 in which the adjustable means for varying the relation of the guide to the mandrel comprises an adjustable abutment stop for limiting pivotal motion of the guide mounting arm.

30. Equipment as defined in claim 28 in which the adjustable means for varying the relation of the guide to the mandrel comprises a device for shifting the position of the guide with respect to the pivoted guide mounting arm.

31. Equipment for forming tubular articles from a fibrous blanket material, incorporating a heat settable fiber binder, including a rotative mandrel on which the fibrous material is adapted to be wound, a closed loop travelling conveyor belt adapted to engage the fibrous blanket material on the mandrel, a pair of guides for the belt, a pair of pivoted arms for mounting the guides, the arms with their respective guides being pivotally movable between positions establishing a conveyor run lying toward a side of the mandrel and positions establishing a re-entrant conveyor run extended around the major portion of the circumference of the mandrel.

32. A method for forming a tubular article from a fibrous material incorporating a heat settable fiber binder comprising wrapping a blanket of the fibrous material on a rotatable mandrel to shape'the tubular article and while the article is rotated with the mandrel, fio'wing heating gas through the fibrous material to set the binder, the temperature of the heating gas being higher at the later stage of curing the binder than the temperature at the initial stage of curing the binder.

33. A method for forming a tubular article from a fibrous material incorporating a heat settable fiber binder, comprising shaping a blanket of the fibrous material to an article of tubular form, confining the tubular article between internal and external perforate members, flowing heating gas through the perforations of said internal member into said tubular article, ap lying heat to said external member and maintaining the temperature of the internal member below that of the heating gas.

34. A method for making tubular articles from fibrous mineral material comprising forming a blanket of the mineral fibers incorporating an unset heat settable fiber binder, rolling up a length of the blanket with a web of sheet material, the rolled length of the blanket being sufiicient to form a plurality of the tubular articles being made, successively unrolling fractional portions of said length of blanket and separating the sheet material therefrom as it is unrolled, wrapping each successively unrolled portion of the blanket on a mandrel to shape a tubular article therefrom, and setting the fiber binder by passing a heating gas through the fibrous material while it is wrapped on the mandrel.

References Cited FOREIGN PATENTS 570,945 2/1959 Canada.

PHILIP DIER, Primary Examiner.

U.S. o1. X.R.

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