US3150025A - Apparatus for processing fibers - Google Patents

Description

Sept. 22, 1964 G. sLAYTER ETAL APPARATUS FoR PROCESSING RISERS 5 Sheets-Sheet 1 Filed May 25, 1957 1 ATTYS.

Sept 22, 1954 G. sLAYTER ETAI. 3,150,025

APPARATUS PoR PROCESSING PIBERs Filed May 25, 1957 5 Sheets-Sheet 2 I E -4: :NVENORS f @A MB 5 BLAY TER MPM SePf- 22, 1954 G. sLAYTER ETAL APPARATUS Foa PROCESSING FxBERs 5 Sheets-Sheet 3 Filed May 23, 1957 Sept. 22, 1964 G. sLAYTER E'rAl. 3,150,025

APPARATUS PoR PROCESSING PIBERs Filed May 23, 1957 5 Sheets-Sheet 4 zes INVETORS: 'AMES SLAYTEH, BY DALL/'IN DMEM/:Ln

:Pj-E- M,

Sept. 22, 1964 G. sLAYTER ETAL APPARATUS FOR PROCESSING FIBERS 5 Sheets-Sheet 5 Filed May 23, 1957 United States Patent O 3,150,025 APPARATUS FOR PROCESSING FIBERS Games Slayter and Calvin C. Mericle, Newark, Ohio, assignors to Owens-Corning Fiberglas Corporation, a corporation of Delaware Filed May 23, 1957, Ser. No. 661,247 1 Claim. (Cl. 156-376) This invention relates to a method of and apparatus for treating and processing fibers formed of mineral materials and more particularly to a method of and apparatus for fabricating or making mats or bonded bodies of mineral fibers having comparatively high insulating characteristics especially for use as heat and sound insulation.

In the production of fibrous products fashioned from mineral fibers such as fibers formed from glass, slag or fusible rock, it has been a practice to attenuate streams of glass or other mineral fiber-forming material into fibers by engaging the streams with gaseous blasts such as steam, air or blasts of gases above the attenuating temperature of the glass, the attenuation taking place within a forming hood. A binder or adhesive is delivered onto the fibers and the mass of fibers compressed to a desired density and the compressed mass delivered into a heating or curing zone or oven for setting the binder.

In fibrous mats or bodies fashioned by this method, the fibers, which may be in varying lengths from a few inches to several feet, are arranged in the mat or end product in generally parallel planes in the direction of the major surfaces of the mat so that very few, if any, of the fibers are arranged normal to the major faces of the mat or body, and hence the mass of fibers must be compressed to a comparatively high density in order to secure desired compressive strength characteristics. The binder is preferably sprayed or delivered onto the newly formed fibers in the fiber-forming hood but due to the substantial thickness of the mass of fibers, certain regions of the mass may be devoid of binder or the binder is not uniformly distributed so as to effectively bond the fibers throughout the mass. Furthermore, as the fibers are arranged in generally parallel planes in mats formed from the mass, there is a marked tendency for the fibers to delaminate and especially at regions where the fibers are incompletely bonded together.

lel with the major faces of the mat lacks strength characteristics in transverse directions.

The present invention embraces a method of processing mineral fibers to effect a reorientation of the fibers involving the step of feeding a mass of binder impregnated or coated mineral fibers to a region at which the fibers are picked apart, shredded or broken up into comparatively short fibers which are recollected or reformed into a fibrous mat or body having improved strength characteristics and high insulating efficiency.

' An object of the invention is the provision of improved apparatus for disintegrating a mass of mineral fibers and reorienting the fibers to form mats or fibrous bodies.

Another object of the invention is the provision of a method of reorienting mineral'fibers involving the features of applying an adhesive or binder to a mass of fibers, feeding the binder-bearing fibers in a partially cured condition to a station at which the fibers are separated and broken u p into short fibers and tufts of short fibers which are rendered tacky by the partially cured binder, and collecting the separated fibers and tufts of short fibers in a mass or mat of a character having high heat insulating characteristics in which the binder is dispersed substantially uniformly throughout the reformed mass of reoriented fibers.

Another object of the invention is the provision of a method of reforming or reconstructing the fiber orienta- Furthermore, a mat formed of comparatively long fibers lying generally paraltion of a mass of mineral fibers wherein the longer fibers are broken up into short length fibers which are collected out of an air stream in a manner whereby the short fibers are haphazardly arranged and disposed in various directions whereby the transverse strength characteristics of the mat formed therefrom are improved and the density of the mat reduced as compared with mats formed of longer fibers.

Another object of the invention is the provision of a method of processing mineral fibers such as glass fibers which involves the steps of partially curing a polymerizable or thcrmosettable binder or adhesive, such as phenolformaldehyde, in a mass of fibers and breaking up, or shredding the binder-bearing fibers into short length fibers which become grouped in tufts of haphazardly arranged fibers under the infiuence of the partially cured binder and which may be readily collected and compacted to form a fibrous body or mat having high strength properties and heat and sound insulating characteristics, and the binder further cured to establish increased mass integrity in the fibrous body or mat.

Another object of the invention is the provision of a method of processing binder-laden mineral fibers to break up the fibers into short length fibers and reorienting the fibers, the method being applicable for reclaiming, reorienting and reforming waste mineral fibers of various kinds resulting from other processes as Well as reorienting newly formed mineral fibers into usable end products.

Another object of the invention is the provision of a method of processing and reorienting mineral fibers whereby the reoriented fibers may be collected and compacted into various shapes usable for many purposes such as heat insulation for pipes, insulation bats or bodies for appliances such as refrigerators, or structural components such as wall boards, roof boards, panels or the like.

Still another object of the invention involves a method of processing mineral fibers wherein fibers bearing a partially cured binder applied to the fibers in a liquid vehicle are picked apart and broken up to form tufts of short bers rendered in tacky condition by the partially cured binder and wherein the short fibers in the tufts are haphazardly arranged extending in substantially all directions whereby the fibers of the tufts formed into a mat, body or other end product, tend to resist delamination.

Still another object of the invention is the provision of a mat or body of comparatively short length fibers haphazardly arranged whereinA a binder or adhesive is uniformly dispersed throughout the fibers whereby a mat or body of improved strength characteristics is obtained with a minimum quantity of fibers.

Further objects and advantages are within the scope i of this invention such as relate to the arrangement, op-

eration and function of the related elements of thestructure, to various details of construction and to combinations of parts, elements per se, and to economies of manufacture and numerous other features as will be apparent from a consider-ation of the specification and drawing of a form of lthe invention, which may be preferred, in which:

FIGURE l is a semidiagrammatic elevational view illustrating a form of apparatus for carryingout or per-V a modified from of apparatus for carrying out or performing steps in the method of the invention in producing a brous body, mat or board;

FIGURE 6 is an end elevational view of the arrangement shown in FIGURE n FIGURE 7 is a semidiagramma-tic elevational view illustratingv the steps in the method of forming insulation for pipes from the reoriented fibers;

FIGURE 8 is a transverse sectional view taken substantially on the line S-S of FIGURE 7, and

FIGURE 9 is an isometric view illustrating a length of finished pipe insulation fashioned from reformed fibers through the use of the method of the invention.

The method of the invention and the novel apparatus are especially usable in processing orV reorienting glass fibers to form mats or fibrous bodies, but it is to be understood that the method and apparatus may be utilized for processing and fabricating other fibers such as those formed from slag, fusible rock, or other materials.

Referring to the drawings in detail, the arrangement illustrated in FIGURES 1 and 2 is particularly adaptable for processing and reorienting mineral fibers, such as those formed from glass, and collecting-the reoriented fibers in a body of predetermined configuration forming a heat insulating medium for the walls of an appliance, such as a refrigerator, or the like.

As shown in FIGURES 1 and 2, theapparatus for carrying out the method is inclusive'of a frame structure 10 formed with upwardly extending frame members or posts 12, longitudinally extending members 14 and transversely extending bars or cross members 15. Secured to the posts 12 is a plate or member 18 which supports several components of the apparatus hereinafter described.

The apparatus shown in FIGURES 1 and 2 includes a fiber or fiber mat receiving station indicated at A, a fiber picking or carding station B, means for establishing an air stream-for conveying the picked fibers and tufts of reoriented fibers into a fiber Vcollecting and mat forming region.

The fiber receiving station lindicated at A is inclusive of a movable conveyor 2f) of the endless belt type, the upper flight 21 thereof being adapted to Vcontinuously convey,

a group or mat of fibers in a right-hand direction as viewed in FIGURE 1 tothe picker station B. The feeding conveyor 20 is supported'by rolls 2d and 25 which are mounted on suitable journalmeans (not shown) carried by the frame structure 10. yDisposed at each side of the upper flight 21 of the conveyor is a guide plate 28 which preventslateral displacement of the fibers on the conveyor.

Disposed at the upper end region of the conveyor fiight 21 are feed or'nip rolls 30 and 31 which are preferably of corrugated cross-section spaced to facilitate movement` of the fibers to be processed between the rolls. The corrugations assist4 in gripping the fibers to advance the same to the picker apparatus at station B; Supported upon one pair of frame members 14 is an electrically energizable motor 34 which is equipped with a speed changing mechanism (not shown) Venclosed Withinra casing or housing 36, the speed changing mechanism being provided with a driven shaft 33.

"The Vshaft 3 8 supports a pulley'39 which is connectedY by a driving belt 40 with apulley 42 on the shaft sup,-

porting the feed roll 31. v A driving belt 44 is connected` with suitable pulleys for driving the-conveyor ZtlV from the motor '34. The feed roll 3f) is concomit-antly driven from theffeed roll y31 by a suitable means (not shown).

The speed changer 36 is of the'adjustable type and is adapted for regulating the rate of feed ofthe conveyor fiight'Zl andthe feed rolls 30 and 31.

. Supported-upon theframe lf is a suitablehousing 48 which houses or'rencloses picker rolls or mechanism for picking apart, shreddingand breaking Yup the fibers ofV the group' or mat delivered to the yrolls by the'conveyor fiight 2.1. Iournally stuaportedV in suitable bearings within the enclosure 48 are shafts 50 and 52. In the embodiment illustrated, the shaft 50 is equipped with a picker roll 54, the peripheral area of which is provided with a large number of radially projecting circumferentially spaced teeth, spikes or pins 55.

The shaft 52 is equipped With a smaller, though sirnilarly shaped, picker roll 57. The rolls 54 and 57 are disposed so that the teeth or spikes pick apart and break up the fibers delivered to the rolls. The shaft 50 is equipped with a pulley 59 connected by a belt 60 with a pulley 61 mounted upon shaft 62, the latter being journalled in bearings supported by the frame 19.

The shaft 62 is driven by a belt 64 from a pulley 65 on the shaft of an electrically energizable moto-r 67, the latter being supported upon the table or plate 18. A belt 66 cooperates with pulleys on the shafts 50 and 52 whereby the picker rolls S4 and S7 are simultaneously rotated but at differential speeds to effectively pick apart and break up the fibers delivered to the rolls. The wall of the housing 43 is provided with an opening 68 through which the mat or group of fibers is advanced by the feed rolls 3@ and 31 into engagement with the rolls 54 and 57.

The picker or carding rolls function to tear apart or disintegrate the mat'or group of fibers, breaking up the longer fibers into short length fibers and tufts or clumps of the short fibers which are preferably delivered into an air stream and conveyed to a region at which the separated or picked fibers and tufts of fibers are reformed into a mat or fibrous body.

As shown in FIGURE 1, the picker housing 48 is pro-A vided with a tangentialiy arranged, fiber conveying tube or duct '70 which is of substantially rectangular crosssectional configuration. The duct 70 is in communication with a housing or casing 72 in which is disposed a suitable valve, gate or metering means which prevents reverse air iowV through the duct 70 from the air stream employed to convey the separated fibers or tufts of fibers toward a fiber collection zone. l

As particularly shown in FIGURE 1, the valve means is in the form of a rotor 73 supported upon a shaft '74 driven by a chain 75 from a sprocket 76 mounted upon a shaft 77 which is driven by suitable speed reducing means contained Within a housing 79 which in turn is driven by a motor (not shown).

The rotor 7S is formed with circumferentially spaced, radially extending plates or vanes 81 which provide metering chambers or spaces 82 defined by adjacent vanes.

The arrangement is inclusive of a means for establishing Vair flow through the housing 72 for entraining separated fibers and tufts of fibers in the compartments or chambers 82 as they are successively moved into registration -Withthe air stream. As shown in FIGURE 1, a blower 85 preferably of these-called Roots type includes a transversely elongated housing S7 in which are journalled shafts 89 and 90. p A V Y 'Ifhe shafts 89 andV 9i) respectively, support blower rotors 91 and 92 which are rotated simultaneously andare suitably shaped or configurated to establish an intermreshingrrelationfor moving air from an inlet tube 95. 'to an outletttube 96, the latter being Vin communication` with a lower region lof the metering housing 72 as shown in FIGURE V2. The air inlet tube 95 is equipped withV an air filter or strainer 97. The rotors 91Vand 92 of the blower-85 are drivenby a belt 1,03 from a pulley mounted tion uproviding insulation for thewalls of an applianceV Y such as a refrigerator V107. i

The arrangement is inclusive ofrneansV for establishing a substantial air stream of high velocity for entraining and conveying the fibersY and-fiber tufts delivered thereinto from the conveying tube or duct 105. As particue larly shown in FIGURE 1, this means is inclusive of a substantially circular blower 109 having a housing 110 in which is disposed a rotor (not shown) driven by a motor 112 mounted upon a support 114 which is secured to the plate or table 18 of the frame construction.

The central or axial region of the blower housing 110 is provided with an air inlet pipe 116 to admit air into the housing. The tube 116 is equipped with a fitting 118, the latter being provided with a movable valve member 120 which may be adjusted to regulate the admission of air into the blower 109. The blower housing 110 is configurated to provide a tangential air outlet 122 connected with an air conveying tube 124.

As particularly shown in FIGURES 1, 3 and 4, the outlet end of tube 124 is equipped with a tubular fitting 126 which is equipped with a tubular branch member 127 arranged at an acute angle to the axis of the tubular fitting 126 as illustrated in the drawings. The tube 105, which conveys the separated fibers and tufts of fibers from the metering means 72, is connected with the branch tube 127 so that the fibers are delivered through the tubes 10S and 127 into the high velocity air stream moving through the tube 124 and fitting 126 from the blower 109. The entrainment of the picked fibers and tufts of fibers in the air stream is exemplified in FIGURE 4.

The picked fibers and tufts of fibers are separated out of the air stream by suitable means as by filtering the fibers out of the stream upon a reticulated, perforated or foraminous surface. FIGURES 1 through 4 illustrate the collection or deposition of the picked fibers and tufts of fibers in a shape or configuration providing an insulating body or medium for the walls of an appliance, such as a refrigerator, indicated at 107. In insulating an appliance of this character it is desirable that the insulation be of substantially uniform thickness and of uniform density throughout the regions of the exterior walls of the appliance.

As particularly shown in FIGURES 3 and 4, there is fitted into the interior of the appliance a substantially rectangular box-like member or liner 130 of dimensions whereby a space 132 of substantially uniform width is provided between the walls of the box-like member 130 and the walls of the appliance 107. The member 130 becomes, in effect, a matrix for sizing the insulating body or batt formed as the picked fibers and tufts of fibers are delivered into the space 132. The tubular fitting 126 is secured to a Wall 134 of the member 130 in the manner shown in FIGURE 4.

As shown in FIGURES 3 and 4, the forward edges 136 of the appliance walls and the edges 138 of member 130 terminate substantially in a common plane, and a member or element 140 of foraminous or reticulated character spans the space `132 atthe edges 136 and 138 of the appliance and member 130 respectively. The member 140 may be wire mesh, perforated sheet metal or the like, having sufficient open areas to provide for the passage of air, but which are spaced so as to present bridge portions to filter the fibers from the air stream. A wire mesh screen such as that conventionally used for screening windows, has been found to be adequate for the purpose. FIGURE 4 exemplifies the path of traverse of the picked fibers and tufts of fibers delivered into vthe air stream moving through the tube, duct or passage 124. During the initial delivery of picked fibers and tufts of fibers into the space 132,` the fibers entrained in the stream are carried into engagement with the mesh material 140 in the region of least resistance to air flow and the fibers pile up oraccumulate on `the mesh material as shown in FIGURE. 4 As the depth of collectedl fibers increases in one region of the space 132, the air fiow at such region is reduced because of the increasedresistance of the accumulated fibers. This increase in resistance automatically diverts the air` stream and fibers entrained therein toward other regions having a lesser accumulation of picked bers and tufts of fibers. Thus, as the fibers are accumulating in the space 132, the air stream is diverted to the regions of least resistance, viz. the regions having the least accumulation of fibers so that eventually the space 132 is completely filled with picked fibers and tufts of fibers substantially uniformly cornpacted to a uniform density so that the insulating factor is constant throughout the entire wall area of the appliance.

The initial mat, group or mass of fibers delivered onto the conveyor flight 21 is impregnated with a thermosetting resinous binder in a partially cured stage or condition. A resin such as phenol-formaldehyde or urea-formaldehyde in a liquid carrier, such as an emulsion, is applied to the fibers prior to their delivery onto the conveyor and the partial curing may be effected by applying sufficient heat or heated air to volatilize a portion of the liquid carrier and thus effect a partial curing of the resin rendering the same tacky or sticky.

The fibers delivered onto the conveyor fiight 21 are usually of varying lengths from a few inches. to several feet and the binder thereon partially cured. The fibers are conveyed upwardly by the conveyor flight 21 through the feed rolls 30 and 31 into the housing 48 and are delivered into engagement with the rapidly rotating picker rolls 54 and 57. The picker rolls are continuously rotated to effectively pick apart, separa-te and break up the fibers of the mass or mat, the picking, separating and fracturing of the fibers being accomplished through engagement of the spikes or pins on the picker rolls with the fibers.

The picker rolls are operated a-t differential speeds, as for example, the peripheral linear speed of the large picker roll 54 may be six thousand feet per minute, while the smaller picker roll 57 may have a peripheral linear speed of upwards of three thousand feet per minute. The spikes on the picker rolls break the longer fibers into `short length fibers and, due to the presence of the partially cured or tacky binder or resin on the fibers, the short length fibers tend to gather or collect into small tufts or clumps.

The separated or picked fibers or clumps or tufts of bers are discharged into the duct or tube 70 and are f conveyed into a compartment or chamber 82 of the metering means 72 in registration with the terminus of the tube '70. The metering rotor or valve means 73 is continuously rotated at a comparatively low speed to bring the compartments or chambers 82 into successive registration with the outlet of the tube 96 fromthe blower 85 and the inlet of the tube 105.

During the registration of each compartment 82 with the tubes 96 and 10S, the air stream developed or established by the blower 85 scavenges or entrains the picked fibers and tufts of fibers-in a compartment of the metering rotor 73 and conveys them through the tube 105 into the air stream iiowing through the tubular fitting 126 from the tube 124. The separated fibers and tufts of fibers are entrained in such air stream and conveyed into and throughout the space 132 shown in FIGURE 4.

The fibers accumulate in the space 132 in the manner hereinbefore explained to form the insulating mat or body of substantially uniform density throughout the space. In order `to further cure or set the binder or adhesive dispersed through the fibers, the air admitted to the blower 109 through the inlet tube 118 may be heated to a temperature suiiicient to set up or further cure the binder on the fibers.

When the space 132 has been filled with fibers the operator closes Vthe valve and the air inlet to the blower 85. The matrix or memberV may then be withdrawn from the interior of the appliance 107 and replaced by the permanent inner wall construction of the appliance, thus completing the operation of insulating the wall areas of the appliance. The matrix or liner 130 may then be inserted in an uninsulated appliance and the above described operations repeated.

The fibers of the mass or group deliveredonto the conveyor ight 21 may be formed or attenuated from molten glass or other mineral material by engaging gaseous blasts, such as steam, compressed air or intensely hot gases of combustion with molten streams of the material. The adhesive or binder in an emulsion or liquid carrier may be sprayed or otherwise applied to the attenuated libers prior to their delivery onto the conveyor flight 21. Y

The'method of the invention may be utilized in reclaiming otherwise Waste libers as such waste fibers may be blended into the group of newly formed fibers delivered to the conveyor. In addition to the glass fibers, other materials may be blended therewith such as Wood fibers, asbestos libers, vermiculite or other filler materials of a character which may be readily dispersed through the mineral libers by the action of the picker or carding mechamsm;

FIGURES and 6 illustrate a modied form of apparatus for performing the steps in the method of the invention and has particular utility in forming flat mats or comparatively Vdense fibrous boards of the reformed mineral libers. The arrangement illustrated is inclusive of a frame 150 formed of pairs of upwardly extending members or posts 152, 153 and 154 which are joined by longitudinally extending frame members or beams 156, 157 and 158, the pairs of upwardly extending members being joined by transversely extending bars or members 160.

The arrangement is inclusive of a conveyor or liber feeding or advancing means 162, the upper ight 163 of which moves angularly upwardly in a left-hand direction as viewed in FIGURE 5. Secured to the pair of upwardly extending members 152 are journal blocks or bearings 167 which journally carry a roller 162 supporting the conveyor 162. The pair of longitudinally extending members 157 carry journals (not shown) which support a second conveyor supporting roll 170.

The conveyor flight 163 is adapted toreceive the mass of libers 165V from a feeding conveyor 172, one end of which is supported by a roller 174. The conveyor 172 supports and advances the mass'of fibers received from a'flber-forming or liber attenuating mech- Vanism (not shown). The'mass of libers 165 is treated prior to its delivery onto the conveyor flight 163 with an adhesive or other coating material delivered in the form of an emulsion or contained ina suitable liquid car rier onto the Ymass 165.

Where phenol-formaldehyde, urea-formaldehydeY or other thermosettable resin is utilized as an adhesive or bonding materiahthesame may be partially cured by volatilizing a portion of theliquid carrier or subjecting *Y the advancing mat to a sutiicient amount of heat or warm air to partially cure the binder andrenderthe same tacky or sticky. l Y The conveyor flight 163 advances the mass of binder bearing mineral fibers, such as glass libere, to a picker or flberseparating and conditioning station D The picker station-D is inclusive of a housing l?? formed of sheet metal or theVY like supported upon theframe 150. The upper region of the housing 177 forms a chamber '179 in which is disposed a large picker roll Y1130 and two picker rolls 182,V and 184 Vof lesser diameter.VV f

The picker roll 180 is mounted upon a shaft 136V journalled in suitable bearings (not shown) carried byY the frame members 157. The picker roll V182V is mounted upon a shaft V188 and thepicker roll 184 issupported upon a shaft 189 supported uponbearings 191mounted upon vbrackets 193. 'The shaft 188 supporting the picker roll 182 is mounted in substantially theV same manner. I ,Mounted upon frame members 156 is lan lelectrically energizable motor 1792, the shaft of which is equipped with i a pulley 194 which drives arpulley 195 on the pickerrollY shaft 186through a driving belt 196; Also'mounte'd on 8 the shaft 186 is a pulley 198 which drives a pulley 199 mounted upon shaft 188 through a driving belt 200. A driving belt 202 cooperates With pulleys supported upon shafts 188 and 189 to establish a drive to the picker roll 184.

A stripper roll 205 may be utilized equipped with radially disposed pins supported upon a shaft 207, the pins on the roll 205 being longitudinally spaced so as to traverse paths adjacent but not overlapping the pins on the large picker roll 180 for the purpose of stripping bers or tufts of fibers from the picker roll 180. In the embodiment illustrated, the picker rolls 180, 182, 184 and the stripper roll 205, rotate in the same direction as indicated by the arrows in FIGURE 5.

Disposed adjacent and Within an opening formed in the wall of the housing 177 adjacent the upper terminus of the conveyor 162 is a pair of feed rolls 209. The peripheral areas of the rolls 209 are formed with longitudinally extending flutes or recesses forming ridges to grip the mass, mat or group of fibers delivered between the feed rolls. As particularly shown in FIGURE 5, the feed rolls 209 are disposed so as to direct the continuously advancing mass or group of fibers into contact with the spikes or pins on the picker rolls.

Mounted upon the frame members 156 is an electrically energizable motor 212 for rotating the feed rolls 209 and the supporting roll for the conveyor 162. The motor drives a speed reducing mechanism contained within a housing 214, a shaft 215 driven by the speed reducing mechanism being equipped with a pulley 216 and through the medium of a driving belt 217 rotates a pulley (not shown) mounted upon the shaft supporting the lowermost feed roll 209.

The feed rolls are connected by gearing (not shown) for rotating the feed rolls in directions to deliver the bers to the picker rolls. The roll 170 supporting the conveyor 162 is driven by means of a driving belt 218 connecting pulleys carried by the shaft of the lo-wermost feed roll 209 and the shaft supporting the conveyor operating roll 170.

Y The peripheral linearspeed of the large picker roll is preferably about twice the peripheral speed of the smaller picker rolls 182 and 184. The diderential speeds of the picker rolls cause the spikes to tear and separate the fibers' and break up the longer fibers into short lengths. The picked fibers and Vshort length fibers (bearing tacky adhesive'tend to be formed into small tufts, clumps orV groups ofshort length fibers under the Vinfluence of the tacky adhesive. Y

The housing 177 is formed with an angularly disposedY A front wall 22e which terminates adjacent and just above the upper surface of the upper flight 226 of an'endless belt conveyor 228, the conveyor being of foraminous or Y reticulated character upon which the picked or separated Vfibers and tufts of libers are collected out of the chamber 230 defined by thehousing 177.

Y Y The conveyor 22S is supported upon rollers 232, 233,

234 and 235. The rollers 232 and 233 are journalled on brackets supported uponrtheV pairs of upwardly extending frame members 153 and the roller 234l 'is supported upon brackets supported by the frame member 154. The roller 235 isV journalled V,upon brackets carried by extending por'- Y tions of the horizontal frame members 158.

Disposedvbeneaththe upper flight 226 of the conveyor and vin registration with the chamber23l) is a suction box .or receptacle 238 formed of sheet metal and which is adjacent theV feed Vrolls 209,V and ydownwardly through Y chamber 239 intorthe suction chamber 234.

The air stream moving through the chamber 230 entrains the separated fibers and tufts of fibers from the picker rolls and carries or conveys them onto the upper surface of the conveyor liight 226. The conveyor, being foraminous, permits the passage of air from chamber 230 into the suction chamber 234, but the short length fibers and tufts of fibers are filtered out of the air stream and collected upon the conveyor fiight 226 which is continuously moving in a left-hand direction as viewed in FIGURE 5. The conveyor 228 is driven by suitable motive means (not shown) connected with one of the conveyor engaging rollers.

As shown in FIGURE 5, a slidable plate, bafiie or valve member 242 may be provided adjacent the conveyor flight 226 arranged for slidable adjustment lengthwise of the ight 226 so as to vary the effective opening for the passage of air through the flight 226 into the suction chamber 234 whereby to vary or regulate the velocity of the air stream moving through the chamber 230.

The apparatus is inclusive of a gate means for regulating the dimension of the exit, outlet opening or passage above the conveyor flight 226 through which the collected fibers are delivered to be formed into a mat or body. Such means is made adjustable in order that the collected fibers effectively close or seal the exit so as to prevent air fiow through the opening into the chamber 230. The gate means is inclusive of a panel or plate 245 which is mounted for vertical slidable movement in Ways or guides 246 and 247 as shown in FIGURE 6 in parallelism with the apron 222.

The panel 245 is equipped with journal members or bearings 249 which support a shaft 250 on which is mounted a roll 252 which snugly yet slidably fits into a recess 254 fashioned in the plate 245 as particularly shown in FIGURE 6. The periphery of the roll 252 engages and compacts the collected fibers advanced by the conveyor fiight 226 to form an effective seal to avoid air fiow through the passage existent beneath roll 252 and the conveyor fiight 226.

It is desirable to adjust the relative vertical position of the roll 252 in order to compact or compress the fibers adjacent the roll to a desired extent in order to form an effective seal. The ways or guide bars 246 and 247 are provided with bearing members 256 supporting a shaft 258. Keyed to the shaft 258 are toothed pinions 260 which mesh with teeth 262 formed on racks or members 263 secured to the panel 245.

Fixedly mounted upon one end of the shaft 258 is a Worm wheelY 264. Secured to one of the frame members 154 is a shelf 266 equipped with bearing members 268 which journally support a shaft 269, the latter being provided with a worm 271 enmeshed with the worm wheel 264. The worm shaft 269 is equipped wtih a manipulating `or hand wheel 273 for rotating the worm, worm wheel 264 and pinions 261i in order to raise or lower the panel 245 and sealing roll 252. By adjusting the relative position of the roll 252, the fibers between the roll and conveyor liight 226 maybe compressed or compacted to an extent to effect the seal of the ber passage.

Means is provided for compressing or compacting the collected fibers at a compacting station EL The compacting means illustrated includes an endless belt or caterpillar-like member 277 carried by rollers 278 and 279 and an intermediate pressure roller 280. The rolls are supported in bearings carried by a suitable frame (not shown) and are adjustable vertically for regulating the extent of compression of the collected fibers and tufts of fibers delivered out of the chamber 230.

The shaft 250 supporting the sealing roll 252 is equipped with a sprocket 282 connected by a driving belt 283 with a sprocket 284 associated with the conveyor supporting roll 279. The roll 279 may be driven by suitable means (not shown) which also drives the fiber compacting belt 277 and the sealing roll 252.

The apparatus shown in FIGURES and 6 may be utilized -for forming fibrous mats of various densities and thicknesses and is suitable for forming fibrous roof boards of densities varying from about three to twelve pounds per cubic foot. Thus the space between the fiber compressing member 277 and the conveyor flight 226 and the depth of the accumulationv of fibers in the chamber 230 upon the collecting surface provided by the conveyor flight 226 determine the thickness and density of the end product or mat M.

The apparatus is inclusive of means for completing the curling or setting of the binder in the fibers. An oven 286 provides a chamber 287 which may be heated by suitable heaters 288 or by circulating heated air of temperature sufiicient to cure the binder.

Endless belts 290 and 291 are disposed respectively above and below the fibrous mat M and engage the mat as the same moves through the curing over in order to maintain the fibers and tufts of fibers held in a cornpressed state until the binder is effectively set or cured to impart mass integrity to the mat. The cured mat delivered from the oven 286 may be severed into desired lengths or shapes for use as insulating batts or as roof boards or for other purposes.

In the operation of the arrangement shown in FIG- URES 5 and 6, mineral fibers 165, such as glass fibers of varying lengths, are impregnated or coated prior to their delivery onto the conveyor flight 163 with a binder such as phenol-formaldehyde or urea-formaldehyde which may be partially cured by the application of heat or partial evaporation of the liquid or carrier for the adhesive. The adhesive or binder in an intermediate stage of curing is in a tacky or sticky condition, and the mass of fibers 165 and tacky adhesive are advanced by the conveyor flight 163 to the moving feed rolls 209 and into contact with the spikes or pins on the rotating picker rolls 180, 182 and 184.

The fibers 165 of the mass, subjected to the disintegrating action of the picker rolls, are separated or torn apart and broken up into short length fibers preferably of one inch or less in length. The picking operation effectively disperses the binder or adhesive throughout the short length fibers whereby the binder in the end product is very thoroughly and homogeneously distributed throughout the product.

The separated and broken up fibers from the picker rolls tend to form into small clumps or tufts under the influence of the tacky adhesive, and the separated fibers, tufts or clumps are entrained in the air stream flowing downwardly through the chamber 230 established by the differential or reduced pressure existent in the suction box or chamber 234. Y

The conveyor 228 is continuously advancing whereby the fibers collecting upon the upper fiight 226 are conveyed toward the exit passage beneath the sealing roll 252. The rate of feed of the mass 165 of fibers and the rate of movement of the collecting conveyor 5228 may be regulated to vary the depth or quantity of the accumulated fibers depending upon the density and thickness desired in the mat or end product.

The relative vertical position of the sealing roll 252 is adjusted by manipu-lating the hand wheel 273 so as to compact the fibers moving through the passage between the roller 252 and the conveyor fiight 226 to prevent flow of air to the interior of the passage 23). By sealing the exit passage for the fibers from the chamber 230, the air is admitted to the chamber 230 through the space adjacent the feed rolls 289 so as to establish a continuously moving air stream around the picker rolls and downwardly through the chamber 230 to entrain the fibers for disposition upon the conveyor fiight 226.

The accumulation of bers on the conveyor flight 226 are advanced beneath the fiber compacting or compressing means` at station E which determines the thickness of the mat M. The mat M is continuously advanced between the retaining belts 290 and 291 through 4the i l curing oven 286 in which the binder in the mat is completely set or cured under the iniiuence of heat or by the flow of heated air therethrough. t

FIGURES 7 and 8 are illustrative of another form of apparatus for carrying out the method of the invention. In this form the reconstructed or reformed mineral fibers may be oriented into hollow cylindrical or tubular configuration of a character suitable for forming insulation for pipes and the like, the end product produced by the method performed on the apparatus being illustrated in FIGURE 9.

The arrangement of FIGURE 7 illustrates an apparatus for forming fibers from molten glass or other fusible mineral material. The fiber-forming apparatus is inclusive of a pair of hollow rotors 300 having perforated peripheral walls. The rotors are supported upon hollow shaftstlZ which are rotated by suitable motors (not shown) at speeds sufficient to project molten glass or other mineral material delivered into the interior of the rotors through the perforations under the influence of centrifugal forces.

A stream of glass or other mineral material is directed from a forehearth and feeder construction (not shown) into each of the hollow shafts 302, the glass being at a temperature rendering it fiowable so that it may be projected through the orifices in the rotor constructions 3fi0.

Surrounding each of the shafts 302 and disposed adjacent each of the rotors is an annular burner 364 of the Vinternal combustion type having an annular orific through which are annularlyshaped, high'velocity gaseous blast 3% is projected in concentric relation with the peripheral surface of a rotor which engages the outwardly projected bodies or primary filaments of glass from the rotors to vattenuate the same to fibers.

The burners 304 are arranged to receive a mixture of fuel gas and air which is substantially completely burned within a combustion chamber formed in each of the burners 3ft/fand the intensely hot burned gases projected through the annular restricted orifices. The fibers thus formed are directed downwardly by the blasts through a forming hood or enclosure 310. A suitable binder such as phenol-formaldehyde or urea-formaldehyde in an emulsion or liquid carrier is sprayed onto the fibers in the forming hood 310 by means of applicators 312.

The fibers in the forming hood fait) are collected or deposited upon an upper flight 3i5 of an endless belt conveyor 3i7 of the foraminous or reticulated type, the conveyor being supported upon rolls 3i9, one of which may Y be driven by a suitable motor (not shown) so as to advance the upper flight 315 in a right-hand direction as viewed in FIGURE 7. The forming hood Si@ and the conveyor supporting Vrolls are, mounted upon a suitable frame 320. A Y

, Disposed beneath the upper flight SiS is a receptacle 322 which defines a chamber 324i. A'ftube or duct 32S in communication with the chamber 324- is connected with a suction blower or other suitable means (not shown) for establishinga subatmospheric Vor reduced pressure in the Y I, chamber 324. -Thereduced pressure in chamber 324iV as- FIGURE l.

' adaptable for insulating pipes. matrix or mold 332 of generally cylindrical configuration Y the mat or group of ,fibers from the forming hood 310 and convey them between the feed rolls 30' and 31.

The feed rolls deliver the mat of fibers into a housing 48 containing the ber picking or carding apparatus. The picking apparatus is inclusive of a roll S4', the periphery of which is formed with radi-ally extending spikes or pins. Arranged adjacent the roll 54 is a picker roll 57 of lesser diameter, the periphery of which is provided with radially projecting pins which rotate close to but do not overlap the pins on the roll 54 during rotation of the rolls.

The conveyor 20 and the feed rolls 30 and 31 are driven by a suitable motor 34. The picker rolls S4' and 57 are driven through suitable pulleys and driving belts 60 and 64 from a motor 65. The housing 48 enclosing the picker or oarding rolls is equipped with a discharge duct '/"fi' which conveys the picked fibers, short lengthl fibers `and clumps or tufts of fibers to a fiber metering or valve means contained within a housing 72.

The metering means is inclusive of a rotor 73 equipped with radially extending blades Si' providing compartments or chambers which are adapted to be brought into successive registration with the fiber discharge duct 79 during rotation of the rotor 73. The rotor is driven at a comparatively low speed through a gear reducing mechanism and motor arrangement of the character shown in A blower 8S establishes an air Astream to convey the fibers in the chambers of the metering means yaway from the metering means.

Y The blower 85 is driven by a suitabley driving belt 103' which is driven through a pulley arrangement and belt 64 from the motor The blower Se" is provided with a suitable air inlet and an air outlet tube 9S which is in communication with the fiber metering chamber 72'. An outlet tube MP5 is connected with the metering chamber whereby the stream of air established by the blower engages the fibers in the metering chambers of the rotor 73' and conveys them through the tube M5.

A blower 169. drivenby a motor lf2 is connected with an air inlet pipe 116 equipped with a heating arrangement 330 for preheating the air admitted to the blower. The air outlet pipe l24 from the blower 199 is connected with a fitting 126' equipped with a branch tube E27 which is connected with the outlet tube .1165 of the fiber metering frneans, 72. Y

VIn the embodiment illustrated in FIGURE 7, the fibers from the picker or carding apparatus at station B are reformed or reoriented in forming hollow cylindrical or tubular shaped fibrous bodies of acharacter particularly The apparatus includes a one end of the mold 332V are fashioned to cone-shaped con- URE'l. VThe apparatus at the Vpicker station B is inciu-V t theconveyor is inclined upwardly and adapted to receive figuration, the convergent regions of the cone-shaped cony figuration being equipped with a collar or annular member 339which surrounds the mandrel and is in snugl engagement therewith but permitting rotation of the mandrel S37 independently of the mold 332. Y Y The fitting 126 is connected with the cone-shaped configuration of the matrix component 335 as shown in FIG- ridge 349 which, during rotation of the mandrel 33,7 assists Y Vin advancing the fibers accumulating in the matrix 332.

Disposed adjacent the end of the mandrel 337 exterior of the mold is a housing 342 enclosing gear reduction mechanism which is connected with suitable transmission gearing contained in a second housing 344 driven by a motor 346. The mandrel is rotated at Ia comparatively low speed through the speed reducing and power transmission gearing contained within the housings 342 and 344.

Surrounding a portion of the matrix or mold 332 is a hood 348 equipped with an exhaust duct 350 which may be vented to the atmosphere or connected with a suction blower. The region of the mold 332 in registration with the hood or chamber 348 is provided with a comparatively large number of perforations or openings 354. The openings or perforations 354 facilitate the passage of air from the interior of the mold 332 into the exhaust hood 348 but are small so yas to prevent the passage of tufts of bers which are retained within the annular space between the matrix 332 and the mandrel 337.

The air stream in the tube 124', laden with the picked fibers or tufts of fibers delivered into the air stream by the tube 135', conveys the fibers and tufts of fibers into the conically-shaped end region of the mold or matrix 332. The velocity of the air carries the fibers and tufts of fibers in a right-hand direction into the annular space between the mold 332 and the mandrel 337, the fibers accumulating against the fibers and tufts of fibers already compacted by the air stream in the said annular space.

The mandrel 337 is supported by the housing 342 enclosing power transmission gearing and is rotated in a direction to cause the spiral ridge 340 to assist in conveying the fibers in a right-hand direction as viewed in FIG- URE 7.

The fibers are substantially uniformly compacted in the region surrounding the mandrel under the influence of the velocity of the air stream. The moving air and fibers entrained therein will be automatically diverted Within the mold toward the region of least resistance, that is, toward the region which has not received its proper complement of fibers. Thus the air-entrained fibers are uniformly deposited and compacted or compressed throughout the entire crosssectional area of the mold 332. The air of the stream escapes through the perforations 354 and is exhausted through the hood 348.

Disposed adjacent the hood 34S and surrounding a perforated region 360 of the mold 332 is a second hood or chamber 358. The hood 35S is formed with an air inlet pipe 362 which is connected with a supply of heated air at a temperature suicient to effect a further curing of the adhesive or binder dispersed throughout the compacted fibers `and tufts of fibers in the annular space surrounding the mandrel.

Disposed adjacent the second hood 358 is an exhaust hood 366 provided with an exhaust outlet 367. The extremity of the mold 332 preferably terminatesat an openin a Wall 368 of the exhaust hood 366 through which the annular' body 370 of fibers is delivered from the mold 332.

Thus heated air is delivered under pressure by a blower or other means through the inlet pipe 362 through the hood 358 and through the perforations in the region 36) of the mold 332 so that the heated air is Vforced through the compacted fibers adjacent the region 360, the air being moved through the fibers toward the exhaust hood 366 and is exhausted through the outlet pipe 367. Thus the binder or adhesive in the reconstructed or reformed fibers forming the body 375 is further cured, for example, to a so-called C stage, through the delivery of heated air through the cylindrically shaped body 370. The continuous rotation of the mandrel 337 is effective to prevent the adherence of the fibers to the mandrel during the body forming and binder curing operations.

The short length fibers in the tufts of fibers extend in virtually all directions and the binder is homogeneously dispersed throughout the fibers.` Thus the fiber orientation in the annular body 370 is greatly improved yand the strength characteristics are substantially uniform throughi4 out the body. The improved orientation of the short length fibers and uniform distribution of the binder in the body provides more efiicient insulation with a reduced quantity of fibers.

One or more additional hot air chambers and exhaust chambers may be employed until full and complete curing of the binder in the fibrous body is obtainned. As shown in FIGURE 7, an additional hood 372 is provided equipped with a hot air inlet tube 374 through which hot air is delivered into the chamber 375 through which the body 37() is advanced. The air in the chamber 375 may be exhausted through an additional exhaust chamber (not shown) similar to the exhaust hood 366.

The raised spiral configuration 340, which may be provided on the mandrel 337, is preferably heated as for example by electrical induction or other suitable means in order to foster or accelerate the curing of the binder on the fibers adjacent the periphery of the mandrel.

It is to be understood that other means of heating the binder or adhesive in the librous body 370 in order to set or cure the binder may be utilized if desired. For example, electrically heated elements or units may be disposed longitudinally of the fibrous body 370 to project heat onto the body in order to cure the binder. Pairs of guide rolls 376 may be disposed along the fibrous body 370 in order to support and guide the body during its traverse through the curing stations.

The hollow cylindrical fibrous body 370 which is to form pipe insulation may receive an overwrap or covering of material 380 which may be applied by a suitable wrapping apparatus. The covering material 38d may be cloth or textile or may be a thin mat of bonded mineral fibers or other suitable covering.

As diagrammatically shown in FIGURE 7, a frame construction supports a rotatable spider or member 384 equipped with one or more rolls 386 of wrapping material 380, the spider 384 being rotated by suitable means (not shown) for revolving the rolls 386 of Wrapping material around the body 370. The overwrapping operation is carried on continuously at a speed proportionate to the rate of advancement of the brous body 370 in order to establish a uniform Wrapping on the body.

The body 370, after receiving the overwrap material 380, may have a wall thereof slitted longitudinally by means of a rotatable slitting or severing knife 390, the wrapped body being supported by one or more supporting and guide rolls 392, one of which is shown in FIG- URE 7. The wrapped fibrous body may be severed into predetermined lengths by means of a severing knife or cutter 394 forming individual wrapped bodies 370', one of which is shown in FIGURE 9. The longitudinal slit 395 formed by the slitting or severing member 390 is shown in FIGURE 9. The overwrap material 380 may be coated with a suitable adhesive or other coating to causethe material to adhere to the cylindrical periphery of the fibrous body 370. i

At the region of entrance of the air tube'126 into the mold construction 332, the interior of the mold in the space between the periphery of the mandrel 337 and the inner Walls of the mold components 334 and 335 may be equipped with semi-cylindrical nozzles (not shown) connected with the extremity of the air tube 126 in order to assist in the distribution of the short length fibers and tufts of fibers circumferentiallyof the mold in which the fibers are collected and compacted.

From the foregoing description of the arrangement `shown in FlGURE 7, it will be 4apparent that the method resulting from the use of the apparatus is continuous from the formation of the mineral fibers to the completion of severed lengths lof pipe insulation material. Briefly the operation of the arrangement of FGURE 7 is as follows: The glass or other mineral fibers are formed by directing annular blasts into engagement with outwardly projected bodies or primary filaments of glass extruded through the perforations in the rotors Stift under the action of centrifugal forces of rotation. The attenuated fibers move downwardly through the forming hood 31th and during such movement a binder is applied to the fibers by means of the applicators 312 or other suitable means. Additional binder may be delivered onto the fibers exteriorally of the forming hood 31d if desired. The binder coated fibers are collected upon the fiight 315 of the endless belt conveyor 317 under the influence of subatmospheric pressure existent in the chamber 324 disposed beneath the conveyor flight 315. i

The mass or mat of fibers collected on the fiight 315 is continuously advanced to the conveyor flight Z1 which directs the mass or mat of fibers between the feed rolls 30 and 31 for delivery to the picker station B. The mat of fibers delivered to the picker rolls 54 and 57 is picked apart, shredded and the longer fibers broken up into short length fibers which, under the infiuence 4of the tacky adhesive collect or tend to collect in small clumpsor tufts which are delivered through the tube '70 to the metering means 72.

Air from the blower 85 entrains the fibers .and tufts of fibers in the metering means 72' and conveys them through the tube 195 into the air stream moving through the tube 124 which entrains the fibers and delivers them into the interior of the mold or matrix 332. The mandrel 337 is continuously rotatedat a comparatively slowV speed and through the medium of the spiral ridge configuration 340 and the pressure of the air stream delivered into the mold advances the fibers andV causes them to .be com= pacted and compressed to a substantially uniform density in the mold space. The rotation of the mandrel 357 also prevents the adhesion Vof the fibers to the mandrel.

The heated air delivered into the mold through the tube 126' is exhausted Vthro-ugh perforations 354 in Vthe wall of the mold in registration with the exhaust hood 348. Additional heated air is introduced into the hood 353 and into contact with the binder in the fibers within the mold .and is exhausted Vthrough an exhaust hood 365; Additional heated air may be directed through the hoody 372 into contact with the fibers in the fibrous body 370 in order' to complete the curing operation of the binder or adhesive. The body 37d in which the binder has been completely cured is advanced to the wrapping station at which `the wrapping material 36) is applied. The rotary slitting knife V39? slits or severs one-wall of the hollow cylindrical body throughout its length and the cutter 394` severs the wrapped body 370 into desired lengths.

It is to be understood that while a rotary apparatus 3th) t the longer'fibers into shortv length fibers, the binder or adhesive onrthe fibers is uniformly dispersed andthe short length fibers reoriented `so that when they are compacted in the ,final product, theV fibrous body is of comparatively low density having high strength characteristics and au efiicient insulating factor.

The method of the invention hasmany advantages and Y merits over prior `methods ofV forming insulating mats.V By completely disrupting a mass or mat of fibers coated with binder in a tacky condition Iat a picker or carding station,V

the longer fibers are broken up into short length fibers and the fibers, which in the original mass or mat were generally disposed in parallel planes, are completely reoriented and reformed in the mats, batts or products formed by reassembling andV compacting the picked fibers. The fiber orientation or reformation wherein the short length fibers Vproject or extend in all directions ,results in products endowed with substantially uniform strength characterf istics in all directions whether the end product is fashioned as insulation for an appliance as illustrated in FGURE 4, a fiat fibrous mat, batt or dense roof board such as may be fashioned through the use of the method performed by the apparatus shown in FlGURE 5 or a hollow cylindrical body such as pipe insulation formed through the use of the arrangement shown in FIGURE 7.

The fibers are uniformly distributed throughout theV end product through the use of the method and the binder or adhesive uniformly dispersed throughoutV the short length fibers so that the end product has no unbonded fibrous regions. rhere is substantially little or no wastek of fibers in the utilization of the method. The methodV is especially adapted for blending various kinds of fibers delivered to the picker station as the action of the pickers distributes and disperses the binder throughout the short length fibers resulting from the action of the pickers. Furthermore fibers impregnated with bonding material as waste from other processes resulting through defective processing, trimming or sizing may be coated with tacky binder and fed to the picker or they may be blended with newly formed fibers and the blend delivered to the picker station and processed4 in accordance with the method disclosed and described.

It is apparent that, within the scope of the invention, modifications and different arrangements may be made other than is herein disclosed, and the present disclosure is illustrative merely, the invention comprehending all variations thereof.

We claim:

Apparatus for processing mineral fibers including7 in combination, a plurality of picker rolls, means for delivering a mass of mineral fibers of Varying lengths bearing a re-sinous material in a tacky condition to the picker rolls, means for rotating the roll-s to pick apart the fibers of the mass and break up the longer fibers into short length fibers and disperse the tacky resin through the fibers whereby the picked fibers are adhered in small tufts by the tacky material, a reiatively stationary cylindricallyshaped matrix, a mandrel of lesser diameter than the matrix extending into the matrix, means establishing an air stream adapted to entrain and convey the tufts of fibers into the matrix to form a hollow brous body defined by the matrix and mandrel, aspiral ridge formed on the mandrel, means for rotatingV the mandrel, means for applying heat to the fibrous body in the matrix to set the resinous material and impart mass integrity to the body, means for applying a covering material to the fibrous body,

a rotatable slitting means disposed in the path of the adand severing means arranged to sever the advancing fibrous body int-o predetermined lengths.

vReferences Cited inthe file ofiy this patent UNITED STATES PATENTS 1,984,649 McDonald et `al. Dec. 18, 1934 2,048,817 jlosengarth T July 2S, 1936 2,152,901 Manning Apr, 4, Y1939 2,219,285 Allen et al. t Oct. 29, 1940 2,288,072 Collins a June 30,V 1942 2,5s9,`oss Laxman j g Mar. Y1i, 1952 2,609,312 FarrellV a Sept. 2, 1952 2,539,759 Simison a May 26, 1953 2,653,355 Essman Sept. 29, 1953 2,702,069 Lannan Feb. 15, 1955.V 2,702,261 Bacon et al. u Feb. l5, 1955 2,723,705 Collins New 15, 1955 Y FOREIGN PATENTS Vi Y 161,843 Australia V Mar. 10, 1955

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