US1966725A - Pipe coating method and machine - Google Patents

Description

I July 1-7, 1934.

w. A. KRANER PIPE COATING METHOD AND MACHINE Filed June 14, 1933 6 Sheets-Sheet l W Mw 4 A Z r M wf w JH mHHLH July 17, 1934. w. A. KRANER PIPE COATING METHOD AND MACHINE Filed June 14, 1953 6 Sheets-Sheet 2 INVENTOR. Warren ,4. k ra/v'er ATTORNEYS.

July-l7, 1934. w. A. KRANER PIPE COATING METHOD AND MACHINE Filed June 14, 1933 6 Sheets-Sheet 3 INVENTOR. VZ a/"rer/ A. {fa/7e! ATTORNEYS.

Judy 17, 1934. w. A. KRANER PIP E COATING METHOD AND MACHINE Filed June 14, 1953 6 Sheets-Sheet 4 INVEN TOR. H arren 4. M'afler m Ii F F W swig. N W34 w. A. KRANER PIPE COATING METHOD AND MACHINE Filed June 14, 1933 6 Sheets-Sheet 5 F'IE E IN VEN TOR. Warren 4. Kramer ATTORNEYS.

W. A. KRANER PIPE COATING METHOD AND MACHINE Filed June 14, 1933 6 Sheets$heet 6 INVENTOR. Warren ,4. Era/76f ATTORNEYS.

m chine incorporating Patented July 17, 1934 PIPE COATING METHOD AND MAQJHINE Warren A. Kroner, San Francisco, Calif" assiznor to Cement Wrapped Pipe Company,

PATENT OFFICE Ltd San Francisco, Calif" a corporation of Arizona Application June 14, 1938, Serial No. 675,659 24 Claims. (Cl. 2M0) This invention relates generally to methods of applying protective coatings like hydraulic concrete to metal piping or and to machines useful for methods.

It isa general cylindrical forms,

carrying out such.

object of the invention to generally improve methods and machines of the above character, to make possible the manulecture of a uniform coating or armor or high protective value at relatively low cost.

A further object of ride an improved method oi ter which will make possible the invention is'to pro the above charac= a dense and hard protective coating which will be relatively tree or objectionable voids.

Another object or the invention is to provide a machine for applying plastic material like hydraulic concrete or .to a pipe or cylindrical form.

hydraulic concrete mortar which will operate a relatively high speed, and which will apply a foraminous reinforcement in proper embedded position simultaneously with plastic material.

application of the Further objects or the invention will'appear the following description irlwhich the preferred embodiment of the invention has set forth in detail in conjunction with the eo= companying drawings.

Figure l is end view,

illustrating a rue the present invention.

2 is a view similar to Fig. 1, out looking toward the opposite end of. the machine.

Fig. 3 is a side elevational view oi a portion of the machine shown in illustrating particularly means the pipe being coated.

side elevational detail, partly in illustrating the centers tor roupper side of Fig. i is a cross section,

Figs. 1 and 2, and

i or vibrating the tatacly supporting small pipe or other term he= ins coated.

Fig. 5 is a plan view, or the reinforcing material.

Fig. 8 is a plan view,

illustrating the wrapping illustrating the complete machine in operation for the coating cl 2. length of pipe.

Fig. '7 is a plan view,

in cross section, illustrating a portion or the carriage which supports certain operating parts of Fig. 8 is a side elevational view.

the machine. partly in cross section, illustrating means for supporting the pipe or other form to be rotated, and to be coated.

Fig. 9 is a side section, of the continuation Fig. 8.

elevatlonal view, partly in cross of the left side of 'Referrlng first to the shown in Fig. 8, the machine consistsgenerally plastic Fig. 10 is a side elevational detail, incross section, showing the guide structure over which the plastic material passes in its advance upon the pipe or other form being coated.

Fig. 11 is a cross sectional detail taken along 60 the line ll-ll of Fig. 10.

Fig. 12 is an enlarged detail, showing the manner in which the toraminous reinforcement becomes embedded in the layer of plastic mate rial, thru the eflects of tension and vibration. M

Fig. 12A is a cross section taken along the line 12Al2li of Fig. 12.

Fig. 13 is a cross sectional detail, illustrating periorating means which can be utilized where paper is employed as an outer surfacing.

The method incorporating in the invention can be best understood after a detailed description of the machine illustrated in the drawings.

general layout in plan,

of a pair of structures it and it for supporting a pipe 12 or other cylindrical term, for axial rotation. Arranged along one side or the pipe 12 there is a carriage 13 adapted to operate along a traclr is. The carriage 13 supports various mechanical elements which serve'to apply the material to the pipe 12, and may also carry a mixing apparatus it for supplying plastic material in proper condition. It he explained that while the machine is in op eration with the pipe 12 being continuously ro tatcd in one direction, the carriage is moved continuously lengthwise or the pipe, and the plastic material is applied spirally or helicoiclally,

as illustrated.

Referring now to Figs. land 2, the carriage it consists of a suitable irarne llwhichcan he formed of structural steel members, as shown. The lower portion of this frame carries wheels 18 for operating upon the track i l. Carried by the frame 17, thru certain elements to he presently described, there is a guide structure 19. It is over this guide structure that the plastic material is conveyed, during its applicstion to the pipe 12.

The particular details shown for the guide structure 19 can be explained by reference to Figs. 10 and 11. The principal part of this guide structure is formedv by a channel 21 having its flat back side uppermost. In order to operativcly support channel 21, a plate 23 underlies its intermediate portion, and the ends of this plate are secured to the depending side channel flanges 24. A stirrup 26 underlies plate 23 and these parts are pivotally connected to- 1 i of bolts 31 which can be engaged in any one of several apertures in the upright members 30.

Yoke 28 is in turn adjustably mounted on ele- It is.

ments 98 as will be presently explained. evident from what has been explained that the support for the channel 21 permits universal movement of this channel with respect to the pipe being coated. In other words this channel can be swung about a generally upright axis at various angles with respect to the axis of rotation of the pipe, or it can be tilted at various angles with respect-to the horizontal,

In order to provide means for continuously feeding a layer of plastic material upon the upper surface of the channel 21, I provide a hopper 33, which can be made of sheet metal plates, welded together. 21, and is preferably positioned substantially co-axial with the axis of pivot pin 27, so that varying amounts of material within the hopper has substantially no effect upon counterbalancing of the channel. For reasons which will be presently apparent it is desirable to retain hopper 33 in its operating position by a hinge connection, so that it can be unlocked and swung to one side. Thus one sideof the hopper has been shown connected to one side of the channel 21 by hinge structure 34. The other side of the hopper is adapted to be retained in operating position by releasable locking means which may be formed as follows:-A rod 36 base. pivotal connection 37 with one side of the channel 21. A collar 38 is slidably positioned upon rod 36 and is urged toward the pivotal connection 37 by compression spring 39. Mounted upon the corresponding side of hopper 33, there is a bracket 41, having a lower flange 42 which is slotted to receive rod 36. Upon swinging rod 36 outwardly and downwardly, collar 38 is freed with respect to flange 42, to permit the hopper to be swung to one side about the axis of hinge structure 34. When the hopper is returned to its normal position, rod 36 can be swung upwardly to again engage collar 38 above the slotted flange 42. In this connection it will be noted that the surfaces of collar 38 are so formed, as to permit its automatic engagement with the upper surface of flange 42, when the rod 36 is swung upwardly.

Certain parts associated with the hopper 33 serve to determine the thickness of the coating applied to the pipe. Therefore it isdesirable to have this hopper occupy a predetermined position with respect to the channel 21 when it is in its operating position. For this reason spacer elements 44 have been shown interposed between the lower side edges of the hopper 33, and the side edge portions of channel 21. The hopper rests upon these spacer bars or elements, when it is in normal. operating position as shown in Fig. 11. Plastic material fed into hopper 33 is fed forwardly over channel 21, towards the pipe to be coated. A smooth'surface for the upper side of the channel can be assured by a sheet metal surfacing 46. In order to prevent any forward hopper wall 51.

This hopper overlies the channel the hopper.

flow of plastic material in the reverse directerial from the hopper in a direction towards the pipe, a plate 49 is removably secured to the The lower portion of plate 49 is provided with a forwardly curved lip portion 52, which overlies the upper surfacing 46 of the channel 21. With this arrangement it is evident that the thickness of spacer elements 44 determines the thickness of the coating applied.

Inorder to secure a uniform and continuous flow of plastic hydraulic Portland cement or Portland cement mortar from hopper 33, below the lip portion 52, I provide means which serves to subject certain parts to rapid and continuous vibration. Thus mounted upon the forward wall 51 of hopper 33, by way of a bracket 56, there is a pneumatic hammer 57. The operating plunger 58 of this hammer bears upon a bar 59, which in turn rests upon lip portion 52. Since lip 52 is somewhat resilient and has its side edges free with respect ,to the hopper, it is vibrated in a vertical direction to insure a smooth continuous flow of plastic material from In addition the main part of the hopper 33; and-particularly the rear wall 47, is subjected to continuous vibration by means of an additional pneumatic hammer 61.

During its movement from the hopper to the pipe, the layer of plastic material fed from the hopper is conveyed along by a strip of suitable material, such as a strip 62of wire screening, or like foraminous metal reinforcement. As is evident from Fig. 10, this stripof reinforcement passes beneath the lower edge of gate 48 and is therefore substantially flat upon the upper surfacing 46 of channel 21 as it passes beneath the hopper toward the pipe. The mounting for the reel supplying this reinforcement will be explained in the subsequent part of the present detailed description. I-Iowever, at this point it may be explained that the reinforcement is preferably placed under tension, and is flattened before it is passed beneath hopper 33. Thus, referring to Fig. 10, the reinforcing strip 62 is shown passed beneath a roller 63 fixed to the side brackets 64. From roller 63 the reinf0rcement passes over roller 66 and fixed roller 6'7, before it passes beneath the hopper 33. Rollers 66 and 67 are carried by the side brackets 68, and roller 66 is adjustable by hand screws 69. The manipulation of -screws 69 makes it possible to keep the reinforcing strip from becoming narrow; that is, it enables an operator to keep one side of the strip from advancing ahead of the other side. In the event the reinforcement tends to advance too rapidly on one side, the screw 69 on that side is turned down to force that end of the roller66 against roller 67, thus causing sufficient friction on roller 67 to allow the retarded side of the reinforcement to 4 catch up.

an extension plate 71. The upper surface of this plate is substantially coplanar with the upper surfacing 46 of channel 21, and interposed between the forward end edgeof channel 21, and adjacent edge of plate 71. there is a lateral slot 72. Plate '71 is fixed to side structural members 73, which in turn are secured to the side flanges 2 of channel 21. For! reasons which will be subsequently explained. plate 711s preferably vibrated rapidly in a vertical direction. For this purpose I have shown pneumatic hammer '74 mounted upon structural members 13. beneath the plate 71. The operating plunger 76 for this hammer engages a cross-bar '17, which in turn engages the under side of plate 71. In order to confine the layer of plastic material during its movement from hopper 33 to plate 71, side guide strips 75 are mounted upon the edge portions of channel 21 (Fig. 19).

During operation of the machine it is desirable to have plate '11 yieldably urged upwardly against the lower side of the pipe, but under varying conditions of operation, it is desirable to adjust the amount of this force- To enable such adjustments there is shown a cross-bar '79 secured to structural members "13, and upon which various counterbalancing weights 79 can be disposed. An increased amount of weight applied to cross-bar 78, obviously tends to reduce the force normally urging plate 11 upwardly against the lower side of the pipe.

Simultaneously with the application of plastic material and iorarninous reinforcement to the pipe, it is desirable to apply an outer surfacing material. Good results have been secured by utilizing ordinary cotton cheesecloth, although paper can be employed if desired.

Thus referring to Fig. 19, there is shown a strip S1 of cheesecloth, which is supplied from a reel to be presently described. As this strip comes from the supply reel, it is passed between a of parallel bars 82, to remove wrinkles and the iike. From bars 82, the clothstrip passes over a guide plate 83, which is carried upon the under side of channel 21. Upon leaving the forward end of guide plate 83, the cloth strip is passed over a roller 8 1, and from thence is passed upwardly thru slot 72, to the upper side of plate 71. 1

1n the event paper is employed in place of cloth, it is desirable to provide the paper with erfo ations to permit extrusion of water and to facilitate subsequent curing. This can be accomplished by the attachment illustrated in detail in Fig. 13. In this case. in place of passing the paper between the bars 82. the paper is passed between a pair of perforating rolls 86 and 87, which are carried by the rear end of channel 21. After being perforated, the paper passes over the guide plate 83, and eventually thru the slot 72 upon the upper side of plate 71, as has been previously described for application of cloth surfacing.

Referring now to Fig. 1, it. will be noted that the foraminous metal reinforcement 62 is supplied from a reel 91, and the surfacing strip 81 supplied from a reel 92. rotatably carried by brackets 93 and 94, which in turn are carried by the upright structural members 96 of a sub-frame 97- The horizontal structural elements 98 of sub-frame 9'? are disposed upon the lower platform 99 of the carriage frame 17. lteferring to Fig. 11 it will be noted that yoke 28 is mounted upon the structural elements 98, and that the sub-frame as a whole at this point is pivotally'connected to the pressure to the ends lower platform 99, by means of pivot pin 101. This pivotal connection permits general adjustment of the sub-frame 97 about a vertical axis alined with the axis of pivot pins 29, so as to enable a general alinement of the reels 91 and 92 with respect to the entire guide structure 19. When the sub-frame 97 is adjusted to a proper position with respect to guide structure 19, it is clamped in such adjusted position to the lower platform 99. For this purpose Fig. 7 shows a portion of the platform-99 provided with a series of holes 103, which can receive clamping bolts.

During certain times, as for example in set- I ting the machine up for operation; it is desirable to raise the outer end of guide structure 19 upon a relatively fixed rest. Thus referring to Fig. 10, a rod 106 has been shown excentrically pivoted to the upright members 96 of the subframe 97. When this rod is swung upwardly it serves as a rest for the guide structure 19, as shown in Fig. 1. However when swung downwardly as shown in Fig. 10, it is disengaged with respect to the guide structure.

Referring to Fig. 1, it will be noted that the sides of channel 21, for that portion of the channel lying between the uprights 96, are pro vided with side rollers 101. These rollers serve to engage the inner opposed faces of uprights 96, thereby limiting lateral movements of the channel, but permitting movements in a vertical direction with a minimum of resistance.

A suitable arrangement for supporting large sized pipes to be coated is shown in Figs. 8 and 9. In this case a rotatable shaft 111 is carried by the journals 112. suitably supported upon a base 113, which can be formed of a pair-"of rails. An expansible chuck 114 is fixed to shaft 111 and serves to engage one end portion of the pipe 12. Arranged below shaft 111, there is a countershaft The journals are in turn 115, adapted to be driven by a motor 116 (Fig.

2) thru the change speed gear sets 11'? and 118, and the gear box 119. Pinion 121 is splined to shaft 115, and engages with a gear 122 fixed to shaft 111. To secure a different drive ratio, another pinion 123 is likewise splined to a shaft 115, and is adapted to engage a gear 124 fixed to shaft 111. A suitable clutch 126 is interposed between the connection from gear box 119 and shaft 115, to disrupt the drive connection if desired.

The other end of the pipe 12 is engaged by an expansible chuck 128 which in turn is rotatably secured to one end of a longitudinally slidable plunger 129. Plunger 129 is splined in the standard 131 and extends through a stationary, hydraulic cylinder 132. A piston 133 operates within cylinder 132, and is fixed to the plunger 129. The parts just described are supported upon a carriage 134, which is provided with wheels to operate upon the rails 113. Hydraulic pressure for operating piston 133 can be provided by a gear pump 136, driven by an electric motor 137. I The hydraulic circuits connected to In order to afford means for quickly shifting carriage 134 longitudinally of the rails 113, I have shown a hydraulic or pneumatic cylinder 139, which is mounted upon the carriage 1134. Within the cylinder 139 there -.is a piston 141, connected to a piston rod 142. The cutcr cnd of piston rod 142 is anchored to an abutment 143, which is fixed to the rails 113. By selectively introducing compressed air or liquid under of cylinder 139, the carriage 13 to its initial position.

134 can be moved along the'rails 113 to a desired position.

Fig. 4 illustrates an arrangement which can be employed when relatively small pipe is to be coated. In this case, in place of utilizing expansible chucks engaging the ends of the pipe,

'the ends of the small pipe 146 are engaged by '14 at a speed bearing a definite ratio to the speed of rotation of the parts. Thus a drive connection tothe carriage is illustrated as follows:-Mounted upon the shaft 111 (Figs. 2 and 8) there isan expansible pulley 151. Mounted within the base 113 there is a rotatable shaft 152, carrying a pulley 153. Pulleys 151 and 153 are connected by cables 154, which are maintained tensioned by the idler pulley 156. Ex-

tending laterally of the track 14, there is a shaft 157, which is driven from shaft 152 thru bevel gears 158. The end of shaft 157 which terminates between the rails of track 14 (Fig. 2) carries a sprocket 159, which is engaged by one end of an endless chain 161. Chain 161 extends the full length of movement of carriage 13, and its other end engages the idler sprocket 162. Underlying the main carriage 13 (Fig. 1) there is a guide channel 163 thru which the upper run of the chain extends. Mounted upon the carriage 13 there is a suitable mechanism, under the control of the operator whereby the upper run of the chain can be locked to the carriage, to drive the same. This locking means need not be described in detail, as its construction will be apparent to those skilled in the art.

After coating 9. section of pipe it is desirable to provide means for quickly returning carriage For this purpose I have shown a suitable motor 171 (Fig. 7), which may operate from pneumatic pressure, and which is adapted to drive the axle for one or more of the wheels of the carriage, thru a chain connection 172, and clutch 173.

- coating operation, it is desirable to provide a mixing apparatus 16 upon the carriage 13. The details of this mixing apparatus need not be described, as many apparatuses of this character which will operate satisfactorily are known upon the market. However it may be, explained that the hydraulic plastic mix prepared in this apparatus is discharged thru a launder 178. to the hopper 33 as shown in Fig. 1. The gate 179, controlling the discharge of the plastic mix, can be operated to eifect opening and closing of the same, by the hydraulic or pneumatic cylinder 181.

To secure a denser final coating it has beenfound desirable to apply vibration to the plastic coating along the upper side of the pipe. For this purpose I have shown a plate 186 (Fig. 3) supported by a bracket 187, through the parallel motion links 188- and 189. A pneumatic vibrator 191 is attached to plate 186 to rapidly vibrate the same ina vertical direction. During operation of the machine plate 186 rides upon the coating immediately after its application, whereby :all of the plastic material applied passes beneath the same and thereby is subjected to vibration. When the machine is not operating, plate 186 can be retained in an elevated position by latch 192, which is adapted to engage pin 193.

Operation of my machine is as follows:The machine is initially set up and adjusted to secure the thickness of coating desired, and to insure proper operation consistent with diameter of the pipe being coated. In this connection the subfra me 97 must be so adjusted that the angularity of guide structure 19 with respect to the axis of the pipe, will apply the material to the pipe with the proper pitch. The metal reinforcing 62 and the cloth strip 81 are properly threaded ,with respect to the guide structure 19, and the ends of these strips are then secured to that end of the pipe 12 at which the coating is to be started. A proper plastic mix prepared-in the mixing apparatus 16, and a charge of this mix is then introduced into the hopper 33. The various pneumatic hammers and vibrators are now put into operation, and rotation of the pipe is commenced, with simultaneous synchronized movement of the carriage 13 longitudinally of the pipe. As the strip of foraminous reinforcement progresses beneath hopper 33, a layer of the plastic mix is applied to the same, for substantially the full width of the reinforcement, and this layer of plastic material is then conveyed together with the reinforcement. In other words the reinforcing strip serves as a conveying medium for the layer of plastic material'fed from the hopper. As the reinforcement progresses over plate 71, the cloth strip 81 is applied to the under side of the same, to be simultaneously wrapped upon the pipe. As has been previously explained the foraminous reinforcement is under tension as it is applied to the pipe. The rapid vertical vibration of plate 71 serves to repeatedly pound the layer of plastic material and likewise the accompanying reinforcement, against the lower side of the pipe, adjacent to or at the region of initial contact with the pipe surface. The effect of such combined tension and vibration upon the reinforcement, causes the reinforcement. to embed itself to an intermediate depth in the layer of plastic material, This can best be explained by reference to Figs. 12 and 12A. As illustrated in these figures the foraminous reinforcement 62 is gradually embedding itself into the layer 9 of plastic material, as the reinforcement progresses along the upper side of plate 71. It has been found that with a Portland cement mix containing sand, and possibly somewhat coarser aggregate material such as fine gravel, the metal screening forming the reinforcing strip will embed itself to an intermediate depth, but will not become embedded sufficiently for it to contact with the outer surface of the pipe. At this point it may be explained that the reinforcement, in order to be effective, must be embedded to an intermediate depth in the layer of plastic material applied to the pipe. If it is applied directly to the outer surface of the pipe, then it will not properly perform its desired reinforcing function. wise if it is permitted to occupy a position adjacent the outer surface of the plastic layer, and then it will not properly reinforce thecoating, and it will be exposed to corrosion.

Likeill In further explanation of the manner in which memes the reinforcement is embedded in the plastic material, as explained with respect to Figs. 12 and 12A, it should be noted that embedding movement of the foraminous reinforcement necessarily is accompanied by extrusion of the plastic material thru the apertures in the reinforcement. Ordinarily extruded plastic material would not form a smooth outer layer portion over the reinforcement, unless troweled. However application of the cloth strip 81 over the plate 71 together with vibration makes a troweling operation unnecessary. Thus it will be noted that while the plastic material is extruding thru the foraminous reinforcement, it is being confined by the cloth strip, which is under a certain degree of tension, and such coniinernent of the plastic material, accompanied by the vibration to which the plastic material is being subjected by plate '31, effectively compacts the extruded plastic material to form a dense outer layer portion. Use of the cloth strip also makes possible application of the coating material at relatively high speed, because the cloth prevents throwing off of the plastic material by centrifugal force.

Plate ii also assists in forming an effective junction between successive convolutions of the plastic material as this material is supplied. Thus referring to Figs. 5 and 12A, it will be seen that the pitch at'which the reinforcement is applied together with the plastic material, is such as to cause adjacent edges of the reinforcement to overlap. Since the layer of plastic material is appliedto substantially the full width of the reinforcement, there is also an overlap with respect to the adjacent edges of the plastic material applied. Plate ll, due to the rapid vibration to which. it is subjected, effec tively pounds down this overlap, so that the resulting coating is of substantially uniform thick ness. Not only does this overlap provide a relatively strong junction between successive convolutions but likewise these junctions are rendered relatively free of voids, due to the surplus plastic material utilized in these regions and the pounding down of the same. it will also be noted from Figs. 5 and 12s. that as the cloth 81 is applied, it is offset so that one edge portion sic of the same extends beyond the adjacent edge of the reinforcement and of the plastic material. This serves to form an overlap between adiacent convolutions of the cloth strip. Likewise the offset manner in which the cloth is applied leaves exposed a certain amount of the plastic material, to form a proper junction with the next convolution. By an inspection of Fig. 12A, the effectiveness of the bond secured between successive convolutions will be appreciated.

The upper vibrating plate 186 has been found highly effective in removing trapped air bubbles from the plastic material. It is desirable to largely remove such trapped air bubbles, in order to densify the coating, so that after the coating material sets and hardens, it affords utmost strength and is less pervious to moisture and chemicals. The lower vibrating plate '11 is not effective in removing air bubbles, for the reason that air bubbles tend to rise upwardly at this point towards the outer surface of the pipe. However when vibration is applied to the upper side of the pipe byplate 186, the air bubbles rise from the outer surface of the pipe towards the outer surface of the coating.

During a coating operation considerable water is squeezed from the hydraulic plastic material, due to the pounding to which it is subjected and to the tension of the cloth surfacing. Although it is desirable to resort to hydraulic curing to insure proper strength and hardness, squeezing out of excess water at this time aids insecuring a highly densified coating.

After the machine has operated to apply the coating to one section of the pipe, further operation is discontinued, and the metal and cloth strips are out. This coated section is now removed from the machine and a new pipe ap-' plied .in position to be coated. The carriage 13 is returned to the other end of the pipe and the operations described above are repeated. After the concrete has set, the ends of the pipe can be trimmed. in any desired manner.

The present specification is a continuation in part of subject matter disclosed in my copending applications Serial Nos. 494,822 and 537,009, filed November 10, 1930 and May 13, 1931, respectively.

I claim:

l. in a method of applying a layer of hydraulic plastic material to a form, the steps of continuously applying a layer of the plastic material upon a strip of foraminous metal reinforcement, wrapping the strip spirally about the form, and applying vibration and tension to the reinforcement as it is applied to cause it to embed itself to an intermediate depth in the layer of plastic material.

2. In a method of applying a layer of hydraulic plastic material to a form,, the steps of continuously applying a layer of the plastic material upon a strip of foraminous metal re-- inforcement, wrapping the strip spirally about the form, simultaneously wrapping a strip of covering material upon the form upon top of the plastic material and the foraminous reinforcement, and applying vibration and tension to the reinforcement as it is applied to cause it to embed itself to an intermediate depth in the layer or" plastic material.

3. in a method of applying a layer of hydraulic plastic material to a form, rotating the form about its axis, continuously supplying a layer of theplastic materialupon a strip of foraminous metal reinforcement. wrapping the strip spirally about the form with the strip together with the plastic material advancing towards the lower side of the form, simultaneously applying a strip of outer surfacing material upon the under side of the metal reinforcement as this reinforcement is advanced toward the form, and then applying vibration and tension to the reinforcement as it is applied to the form to cause it to embed itself to an intermediate depth in the layer of plastic material.

4.111 a method of applying a layer of hydraulic plastic material to a form, the steps of rotating the form about its axis, continuously supplying a layer of the plastic material upon a strip of foraminous metal reinforcement.

wrapping the strip together with the layer ofplastic material spirally upon the form, with the reinforcement being advanced toward the under side of the form, simultaneously applying a strip of surfacing material spirally about the form, with the strip of surfacing material being advanced upon the form upon the under side of the foraminoiis reinforcement as this reinforcement is being applied to the form, applying tension to the foraminous reinforcement and applying vibration to the reinforcement and theplastic material as it is being applied to the form, whereby the reinforcement is caused to embed itself to an intermediate depth in the layer of plastic material, and whereby that portion of the plastic which material is caused to assume a position overlapping the foraminous reinforcement is made relatively compact.

5. In a methodof applying a layer of hydraulic plastic material to a form, the steps 'of rotating the form about its axis, advancing a layer of the plastic material to the underside of the form whereby the layer is wrapped spirally upon the form, rapidly pounding the plastic material near the region where it is being applied to the under side of the form, and then rapidly pounding the applied layer adjacent the upper side of the form, thereby causing removal of air bubbles.

6. In a method of applying a layer of hydraulic plastic material to a form, the steps of rotating the form about its axis, wrapping a strip of foraminous reinforcement spirallyabout the form, causing the metal reinforcement to be applied to the form together with a layer of the plastic material extending for substantially the full width of the reinforcing strip, causing a substantial overlap between adjacent edge portions of the reinforcing strip and of the plastic material applied together with the same, upon the form, and rapidly pounding the regions ofsaid overlap to produce a resultant coating of substantially uniform thickness.

'7. In a method of applying a layer of hydraulic plastic material to a form, the steps of rotating the form about its axis, advancing towards the lower side of the form, a strip of foraminous reinforcement, a strip of surfacing material underlying the foraminous reinforcement, and a layer .of the plastic material upon the foraminous reinforcement and extending for substantially the entire width of the reinforcement, causing the foraminous reinforcement, together with a strip ofsurfacing material, and the plastic material, to be wrapped spirally about the form, with adjacent edges of the foraminous reinforcement overlapping, causing the strip of surfacing material to be likewise applied with overlapping edge portions adjacent the region of the overlap between the edge portions of the foraminous reinforcement, applying tension to. the reinforcement as it is applied upon the form, then applying rapid pounding to the plastic material applied to the form before hardening of the same, to reduce the thickness of. the coating along the region of the overlap and to cause the reinforcement to embed itself to an intermediate depth in the layer of plastic material.

8. In amethod of applying a layer of hydraulic plastic 'material to a form, the steps of continuously rotating the form, continuously advancing a strip of material to the form whereby the strip is wrapped spirally about the form, and continuously squeezing excess water from the plastic material as it is applied.

9. In a method of coating a pipe or like form, advancing superposed strips of foraminous reinforcement and surfacing material toward the form, with the surfacing outermost, causing these strips to be wrapped spirally upon the form, applying a layer of plastic material upon the inner side of the reinforceing strip, and then causing the reinforcing strip to embed itself into the layer of plastic material while simultaneously compacting that portion bf the plastic material which is extruded thru the reinforcing strip.

10. In a machine of the character described; means for supporting and rotating a pipe or other form to be coated, a hopper adapted to receive a mass of hydraulic plastic material and having a lowerdischarge opening, means for guiding a foraminous strip beneath said opening, whereby plastic concrete fed thru said opening is deposited upon said strip, means for applying tension to the foraminous strip as this strip together with the plastic material, is applied spirally about the form, and means for applying vibration whereby during application of the strip to the form it is caused to embed itself to an intermediate depth in the layer of plastic material.

'11. In a pipe coating machine, means for supporting and rotating a form to be coated, a hopper adapted to receive a mass of hydraulic plastic material and having a lower discharge opening, means for guiding a strip of formainous reinforcement beneath said opening, whereby concrete fed thru said opening is deposited upon said strip, means for progressing the hopper and guide means longitudinally of the pipe, whereby the strip of reinforcement together with the layer of plastic material carried by the same, is wound spirally upon the pipe, means for repeatedly pounding the coating'as it is applied to the under side of the pipe, and means overlying the pipe for repeatedly vibrating the coating, before setting of said plastic material.

12. In a machine of the character described, means for supporting and rotating a form to be coated, a framework disposed alongside the form means for progressing the framework longitudinally of the axis of rotation of the form, a guide structure movably carried by the framework and normally disposed at an angle to the axis of the form, said structure having a substantially flat bottom and having its one end terminating adjacent the lower side of the form, said guide structure being adapted to receive a strip of foraminous reinforcement to be wound spirally about the pipe, means for feeding said strip into said guide structure and for tensioning the same, a hopper carried by the frame above the guide structure and adapted to receive hydraulic plastic material, said hopper having a lower discharge opening overlying said guide structure and of a width substantially the same as that of the guide structure, a plate underlying the form" and serving as an extension of said guide structure, and means for feeding a strip of surfacing materialover the upper surface of said plate and beneath said reinforcement.

13. In a. machine of the character described, a guide structure over which a layer of hydraulic plastic material may pass to be applied helicoidally upon a pipe or like form, a hopper overlying said structure to receive a charge of said material, means for feeding a conveying strip beneath said hopper and over said structure, a resilient lip formed upon the'hopper beneath which the plastic material may flow, and means for rapidly vibrating said lip.

14; In a method of coating pipes or like forms with concrete, the steps of applying a layer of the concrete in plastic form' upon a strip of foraminous metal reinforcement, wrapping the strip about the pipe with the concrete between the outer surface of the pipe and the reinforcement, and applying vibration and tension to the V 3,968,725 reinforcement to cause it to embed itself into the layer of concrete.

15. In a method of coating pipes or like forms with concrete. the steps of applying a layer of the concrete in plastic form upon a strip of foraminous metal reinforcement, wrapping the strip about the pipe with the concrete between the outer surface of the pipe and the reinforce-' ment, applying vibration and tension to the reinforcement to cause it to embed itself into the layer of concrete, and then smoothing over the concrete thereby extruded thru the perforations of the reinforcement.

16. In apparatus for coating pipes or like forms, means for wrapping a strip of foraminous metal reinforcement helicoidally about a pipe, means for applying a layer of plastic concrete upon one side of the reinforcement whereby the layer is wound upon the pipe together with the reinforcement, means for applying tension and vibration to the reinforcement. to cause it to embed itself into the layer of concrete on the pipe, and means for smoothing over the concrete thereby extruded thru the perforations of the reinforcement.

17.. In a method of coating pipes or.like forms with plastic 'materiaLthe steps of applying a layer of plastic material upon a strip of foraminous metal reinforcement which is relatively narrow compared to the length of the pipe, wrapping the strip together with the plastic layer helicoidally upon the pipe, tensioning the reinforcement and tamping the plastic material together with the reinforcement as it! is applied to the pipe to cause the reinforcement to embed itself in the plastic material. thereby forming both outer and innerlayer portions of plastic material on the sides of the reinforcement without further application of plastic material, and compacting the outer layer portion to-form an uninterrupted covering for the reinforcement;

18. In a process of the character described, the steps of continuously forming a layer of plastic concrete from a mass of the same. con-,

tinuously conveying said layer away from the mass and wrapping the same about a form, and

"rapidly pounding the layerimmediately upon contacting the same with the form. g 19. In a process of thecharacter described, the steps of continuously forming a layer of plastic concrete from a mass of the same, continuously conveying said layer away from the mass and wrapping the' same spirally about a pipe or like form, and continuously vibrating the layer prior to contacting the same with the.

Pipe.

reinforcement toward the pipe and causing the the steps of rotatfiig a pipe or like form to be coated, applying a layer of plastic concrete spirally to the pipe in sucha manner as tooverlap successive convolutions, land tamping the concrete after application .to produce a substantially uniform coating.

21. In a method of the character described, advancing a strip of foraminous metal reinforcement toward a pipe or like form and causing the same to wrap upon the pipe spirally, continually supplying concrete to said strip while the strip is advancing toward the pipe, causing said concrete to be distributed to cover both sides of said strip, and utilizing said strip as a conveying medium to carry the concrete upon the pipe to form a continuous reinforced'coating.

22. In a method of the character. described, the steps of rotating a pipe or like form to be coated. advancing a strip of foraminous metal same to wrap .upon the pipe spirally, continually supplying concrete to one side of said strip while the strip is advancing toward the pipe. causing said concrete to be distributed to cover both sides of said strip, and utilizing said strip as a conveying medium to carry the concrete upon the pipe to form a continuous reinforced coating.

23. In a method of the character described, the steps or rotating a pipe or like form to be coated, continuously advancing a strip of foruminous metal reinforcement toward the pipe and causing the strip to wrap upon the pipe spirally, continually delivering plastic concrete to one side of the strip while the strip is advancing toward the pipe. causing the concrete to be distributed to cover both sides of the strip. and applying a-covering strip upon the pipe simultaneously with the reinforcing strip and the concrete carried by the same, said latter strip being 5 likewise wound spirally and applied on the outer surface of the concrete.

24. In a method of the character described.

the steps of rotating a pipe or like form to be taneously with application of the reinforcement strip and the concrete, said cloth strip being likewise wound spirally and applied on the 1 outer surface of the concrete under tension.

- WARREN A. KRANER.

Images