JPS628227B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coating device for coating workpieces with granular material, and in particular to a device for wrapping, storing and applying the granular material in a more controlled manner so as to obtain coatings of superior quality. .

1971 with Melton et al. as inventors
U.S. Patent Application No. 198,806, dated Nov. 15, ``Method and Apparatus for Applying Granular Coatings to Workpieces,'' and U.S. Pat. It describes the equipment used to process processed products.

In the device described in the above patent application specification,
Utilizes a combustible fuel-air mixture that is introduced into a combustion chamber with a constricted outlet nozzle at a rate sufficient to increase the pressure substantially above atmospheric pressure. In this case, the mixture is ignited while the inlet valve is closed and the pressure is still at a high level. The combustion that occurs is confined by a narrow outlet nozzle, creating even higher pressures. The hot combustion gases then exit through the restricted outlet nozzle at high velocity during the blowing period. The particulate material is injected into the combustion chamber preferably near the end of combustion and substantially before peak pressure has decreased. The granular material is thus heated and propelled at high velocity from the nozzle toward the workpiece. In this case, the granular material flattens and adheres to the workpiece, forming a coating.

The apparatus described in U.S. Pat. No. 2,972,550, except that the detonable mixture must be used in a long tubular calcining chamber with an open end adapted to sustain detonation waves. Use roughly the same method. The detonation wave causes a virtually instantaneous pressure rise in this chamber due to very rapid combustion. The hot gas also heats the particles that must be ejected just before detonation. The gas is forced out of the open end of the tubular chamber under high pressure, propelling the particles at high velocity toward the workpiece.

In each of these devices, the repetition rate of pulsating combustion is relatively high, for example on the order of 10 times/sec. The coating efficiency, ie the percentage of particles that stick to the workpiece and the quality of the coating, depend primarily on the repeated and uniform injection of particles into the combustion chamber at very precise moments. One of the major drawbacks with conventional devices has been the injector of the particles used. Each device utilized a bulk hopper for particulate material and some type of mechanical-pneumatic dispensing device to meter and dispense the very small amount of particulate material required for each jet. Bulk handling of granular material results in undesirable separation of larger particles from smaller particles. Such devices also generally
Granular material tends to harden from the bulk hopper, resulting in uneven feeding. Furthermore, the highly abrasive particulate material causes the pneumatic valves and conduits to wear out very quickly and are therefore susceptible to failure. Additionally, many particulate materials are subject to oxidation and other adverse effects due to exposure to atmospheric moisture. It is extremely difficult to protect these materials from oxidation during handling in bulk at the coating site.

Similar problems also exist with continuous coating equipment such as flame guns and plasma guns. In this case, the granular material is continuously fed into the hot gas by means of a pneumatic feeding device. In some such devices, a rod or tube containing particulate material is passed directly into a combustion chamber where the hot combustion gases melt the rod or tube, causing
All material is consumed by the flame or becomes part of the cladding. However, in many instances, particulate material is pneumatically picked from the bulk hopper to the coating over a substantial distance, causing equipment wear and clogging of the tubing.

In U.S. Pat. No. 3,461,268, particulate material is enclosed within a pocket of tape and substantially positioned to form one wall of a high voltage spark chamber.
Sparks in the chamber create an explosion that propels the heated particles and the material forming the package toward the workpiece to form a coating. Although such devices are suitable for some types of coatings, the entrainment of the material forming the encapsulating tape has a substantial negative effect on the quality of the coatings concerned here.

According to the present invention, particulate coating material is encapsulated in an elongated tape such that each unit length of the tape contains a predetermined amount of particulate material. The tape is moved past the stripping area at a controlled rate to strip the particulate material from the tape and entrain it into the carrier gas stream. The gas stream heats the particles and gas stream and directs the particles at high velocity through the outlet into the hot gas stream to impinge on the heated particles and form a coating.

One embodiment of the invention includes a combustion chamber with an open outlet, an inlet valve for introducing a series of separate combustible materials into the combustion chamber, and an ignition device for igniting the combustible materials in the combustion chamber. , an encapsulating tape having a plurality of separate pockets each containing a measured amount of granular coating material, a source of air pressure, a stripping location, a drive for sequentially moving each encapsulating pocket of the tape through the stripping location, and a granular material. A pulsating coating system is used, consisting of a control system that produces a separate series of combustion cycles in which the fuel is stripped from the encapsulating tape and injected into the combustion gases.
Due to the extremely high degree of control available for particulate materials, the injection point into the combustion chamber can be controlled to compensate for different particle sizes and different types of coatings.

Another embodiment of the invention provides a continuous cladding device with sources of fuel gas and oxidizing gas that mix within a combustion chamber and ignite so that hot combustion gases exit the combustion chamber at a high rate. The particulate material encapsulated within the continuous tape is continuously moved to a stripping site and a combination of pneumatic and mechanical devices strips the particulate material from the tape and injects it into the combustion chamber of the flame gun.

Yet another embodiment of the invention provides a plasma coating apparatus in which a gas stream is heated by an electric arc and the heating propels the gas stream toward the workpiece at high velocity. The particulate material encapsulated in the tape is moved to a stripping location and a combination of pneumatic and mechanical devices strips the particulate material from the tape and injects it into the gaseous stream either before or after heating the gaseous stream with an electric arc. In this case, these particles are heated and impact the workpiece, forming a coating.

In the method of the present invention, the granular material is enclosed in an enclosure having an inflow surface and an outflow surface, and air pressure is injected into the capsule through the inflow surface to spread the capsule and rupture the outflow surface, thereby dislodging the entrained granular material. A method is utilized which consists of heating the granular material and directing it in intermixing relation to the accelerating hot gas toward the workpiece.

According to the present invention, the encapsulating tape is formed from two film strips. One of these strips is shaped in such a way as to facilitate the introduction of air pressure into the interior of the capsule so that the outlet surface can be ruptured by this air pressure. Preferential air pressure permeation points or holes or weakened areas on the inflow surface may be formed in the tape during manufacture or mechanically formed in bare locations.

In addition, according to the invention, the exposed area and the tape are shaped to facilitate selective penetration of the inner surface of the capsule by air pressure and rupture of a similarly selected area in front of the outflow surface, and to prevent air turbulence within the capsule. Flow channels are created to allow sufficient scavenging of particulate material from the capsule.

In the present invention, a control device can be used that pulls the encapsulating tape past the stripping site with a continuous, uniform force. The position of the capsule is sensed as it approaches the exposed area and a combustion cycle is initiated in response to the capsule reaching a predetermined position. The tape is momentarily tightened at the exposed area, and the granular material is injected from inside the capsule into the exposed combustion chamber using air pressure.

The present invention may also utilize a rotating device that positions each capsule of the encapsulating tape in the open area to provide a high rate of combustion cycles. The invention also relates to tapes of particular shapes suitable for use in such rotating devices.

Embodiments of the coating device and tape according to the present invention will be described in detail below with reference to the accompanying drawings.

A coating apparatus 10 according to the invention as shown in FIG.
has a generally spherical combustion chamber 12 with an elongated narrow outlet nozzle 14. Nozzle 14 directs the hot combustion gases and the particulate material entrained therein to the workpiece. A relatively large inlet valve 16 compared to the outlet nozzle 14 directs the fuel-air mixture into the combustion chamber 1.
2. Air supply 18 delivers compressed air at a relatively high pressure, such as 1000 psi, through pressure regulator 20. The regulator 20 is connected to the vaporizer 22
Generates a pressure of 100psi. In the vaporizer 22 , gaseous fuel is mixed with air and the mixture is sent into the combustion chamber 12 via the inlet valve 16 . The high pressure air is also directed to an injector 24, which will be described in detail below. An injection tube 26 extends from the injection device 24 into the combustion chamber 12 . A conventional igniter 28 ignites the flammable mixture supplied to the chamber 12 by means of an igniter 30 . Timing device 3
2 is the inlet valve 16, the ignition device 28 and the injection device 2
4 are controlled in the order described with respect to the time diagram of FIG.

Encapsulating tape 4 according to the invention as shown in FIG.
0 includes a relatively thick piece or sheet of tape 42 having a series of pockets 44 spaced uniformly apart from each other. Each pocket 44 is filled with a measured amount of granular dressing 46. The granular dressing 46 is sealed within the pocket 44 by a relatively thin sheet material 48. Each sheet material 42, 48 is preferably a plastic material such as polyethylene, but may also be a moisture resistant material if such a seal is desired. The relatively thick sheet material 42 has a thickness
Although it is about 0.004 inch, it is a relatively thin sheet material 4
8 has a thickness of about 0.0005 inches. Each pocket 4
4 is on the order of 1/8 inch to 1/4 inch in diameter depending on the particular application. A series of holes 50 are formed along either or both edges of the laminated tape 40 to provide a positive indexing action as described below with respect to FIG.

2a and 2b show an encapsulating tape 40a according to a variation of the invention. tape 40a
comprises a relatively thick orthopedic sheet material 41 with a hole 41a at each capsule location. Granular material 46a
is a pair of relatively thin film sheet materials 43, 45
Enclose in between. Each capsule is placed within hole 41a. Each sheet of material 41, 43, 45 may be any suitable plastic material, such as polyethylene, and is bonded together at a common location by heat or other suitable means. The relatively thick sheet material 41 may have the same thickness as the sheet material 42 of FIG. Also, the relatively thin sheet materials 43 and 45 are the thin sheet materials 48 in FIG.
The thickness should be approximately the same as that. Tape 40a increases the ease and effectiveness of pneumatically rupturing the capsule, yet is strong enough for high speed indexing and handling.

As shown in FIG.
and suitable equipment (not shown) for transporting it past. Tape 40 is pulled past location 52 by index drive sprocket 54 and then wound onto a suitable take-up reel 56. The exposed area 52 is
An outflow header 58 and an inflow header 60 supported at the end of the injection pipe 26 are provided. The header 60 includes a solenoid-operated valve 64 for admitting air from the high pressure air source 18 for the carrier gas stream.
A pneumatically driven tightening seat plate 68 is pneumatically moved downward to tighten the tape 40 and seal around the pocket 44, and the tape 40 is spring-biased upward by the spring piece 70.

The operation of the coating device 10 is clearly illustrated by the timing diagram in FIG. Timing control 32 actuates sprocket 54 to positively position enclosing pocket 44 of tape 40 over the hole in outflow header 58. This hole communicates with the injection pipe 26. In this case, the combustion cycle represented by pressure line 72 in FIG.
It begins at time 0 by opening the inlet valve 16 as indicated by 4. The pressure within the combustion chamber 12 is then increased through the narrowed outlet nozzle 14 and the fuel-air mixture into the chamber 12.
The high rate of injection by high pressure air source 18 increases the pressure to approximately 100 psi, as shown by portion 72a of line 72. When valve 16 closes, ignition voltage is applied to ignition spark 30 as indicated by line 76 to ignite the combustible mixture within chamber 12. In this case, a very rapid pressure rise occurs, as shown by section 72b of pressure line 72. At approximately the same time that the air-fuel mixture is ignited by a spark, the pneumatic injector 64 is connected to line 78.
Open as shown. 1000psi as mentioned above
The high-pressure air is then introduced into the inflow header 60 and the seat plate 6
8 to push the seat plate 68 downward and tighten the tape 40 to seal the periphery around the enclosed pocket 44 located in the exposed area. In this case, the high pressure carrier gas immediately ruptures the tape 40, stripping the particulate material from the tape 40 and entraining it in the high velocity, high pressure air stream entering the interior of the combustion chamber 12 via the injection tube 26. As soon as valve 64 closes, the pressure equalizes around seat plate 68 and spring piece 70 lifts seat plate 68 to release tape 40. The high pressure blowback from the combustion chamber 12 blows tape fragments up from the top of the injection tube 26. The time limit for injection of particulate material is represented by line 80 in FIG. The granulator then impinges on the workpiece 15 during the time period represented by line 82. The entire combustion cycle occurs within a time period of about 15 msec, and the injected particulate material is added to the combustion chamber during a very short period of this cycle.

In accordance with the present invention, the end of the injection tube 26 is adjustable within the chamber 12 to control the time period during which the particulate material remains within the combustion chamber and is heated by the hot combustion gases. For example, when coating larger particles or particles with a higher temperature, the end of the injection tube 26 may optionally be raised relative to the outlet nozzle 14 so that the larger particles can be deposited into the combustion chamber 1 after combustion of the gas.
heating to a higher temperature by increasing the residence time in the When injecting finer particles or particles with a lower temperature, the injection tube is connected to nozzle 1.
Position it closer to 4.

Adjustment of the location of the end of the nozzle is accomplished using the device 24a shown in FIG. In the device 24a, the first
Corresponding parts of the device illustrated in the figures have been provided with the same reference numerals followed by the reference letter a. In this case, the injection pipe 26
a is slidably disposed within the combustion chamber 12a, and the annular portion between the two is sealed by a 0-shaped ring 90.
The outflow manifold 58a is adjustable and positioned by a nut 92 screwed into a rod piece 94 to raise and lower the end of the injection tube 26a.

As shown in FIG. 6, another encapsulation tape 100 according to the present invention includes a longitudinally extending tubular pocket for encapsulating particulate material. The length of each separate pocket can be varied as desired to provide suitable starting and stopping points, and is formed by the first and second plastic films 102, 104 as described above. Film 102 is grooved to form a tubular cavity for receiving particulate material 106, while the other film 104 is substantially flattened. The side edges of each tape film 102, 104 are, for example, welded seams 1 along the tape longitudinal direction.
They are joined to each other by 08 and 110. tape 1
00 has a substantially uniform cross section along its longitudinal direction, so it encloses a predetermined amount of granular material per unit length. Films 102 and 104 have the same thickness or are relatively thin.

FIG. 7 shows an apparatus 1 using an encapsulating tape 100.
20 is shown. The tape 100 is wrapped around a frame 100a between a pair of fixed cylindrical anvils 122 and 124.
Send from. Each roller may be used in place of the anvils 122 and 124. The film 102 is pulled around the anvil 124 by a pair of positively driven rollers 126, 126 and stored in the take-up reel 128;
30. Each drive roller 126 and take-up reel 130 has sufficient force to separate the films 102, 104 and the weld seams 108, 110 and force the particulate material 106 into the air conduit 132. The above-mentioned stripping device is in an airtight chamber 1.
It is confined within 34.

Oxidizing agent from source 136 is supplied to valve 13 under pressure.
8 and a conventional flame gun 140 via conduit 132.
send to. Gaseous fuel from source 142 is routed to flame gun 140 via valve 144 and conduit 146. In the flame gun 140, this fuel is mixed with an oxidizer and combusted in conventional manner to produce hot combustion gases. These combustion gases exit the chamber through the nozzle at high velocity and impinge on the workpiece 159. A source 148 of inert gas or air is provided to pressurize the chamber 134 via an automatic regulator 150 . The regulator 150 is
The pressure within conduit 132 is sensed via control line 152 and the pressure within the chamber is adjusted to a value slightly higher than the pressure within conduit 132.

In operation of apparatus 120, oxidizer and fuel are supplied to flame gun 140 by opening each valve 138, 144 to ignite a combustible mixture and produce hot gas exiting the gas at high velocity. . When the particulate material is to be applied to the workpiece 159, each drive roller 126 is driven so that the take-up reel 130 maintains sufficient tension on the film 104 to separate the two films 102, 104 from each other. Anvil 12
The film 102 is pulled along the line 2. In this manner, the particulate material is deposited into the conduit 132 at a uniform rate determined by the rate at which the tape 100 is moved along the anvil 122.
exposed to an oxidant stream acting as a carrier gas passing through the oxidizer.

It is clear that the tape 100 provides a highly accurate measure of particulate material and facilitates storing and handling the particulate material. Additionally, the conduit 132 between the location where the particulate material is introduced into the air stream and the flame gun 140 is
Of course, the absolute minimum length can be used to improve powder control and significantly reduce wear on the conduit 132 resulting from the high speed movement of highly abrasive coating materials such as tungsten carbide into the flame gun 140. .

The purpose of the pressurized enclosure 134 is to equalize the pressure on the tape 100 so that the pressure within the conduit 132 does not return to the tape 100 and cause it to break. That is, if the pressure within the conduit 132 does not exceed the pressure that the tape 100 can withstand, then the tape 100 and each film 102, 104 should be placed in the vicinity of the anvils 122, 124 to reduce the size and complexity of the device. It is clear that it can be easily sealed. It is also clear that the oxidizing agent is air, and that air or an inert gas can be used as a carrier in conduit 132 in place of oxygen, and that oxygen be supplied to the flame gun from a separate source. When supplying this oxygen, the need to maintain a positive differential pressure from the interior of enclosure 134 to the interior of conduit 132 is significantly reduced because the potential hazards of using oxygen as a fluid carrier are eliminated. It will be appreciated that in this case the amount of air required to entrain the particulate material is so small that the temperature of the flame within gun 140 does not need to be substantially cooled. Of course, in many applications of flame guns, it is desirable to introduce an inert gas to lower the flame temperature. In this case, it is very advantageous to use air or an inert gas as carrier for the particulate material.

Another coating apparatus 160 utilizing the encapsulating tape 100 of FIG. 6 is shown in FIG. roll 100
The tape 100 from a is passed through a pair of rollers 163,
163 pulls take-up reel 165 around bare mandrel 162 at a controlled rate. Knife 1
64 cuts the film 104 as described below with respect to FIG. The above-mentioned device is a pressurized chamber 16
It is located within 6. A suitable carrier gas, such as an inert gas, is delivered by source 168 to the interior of pressurized chamber 166 via regulator 170 . Conduit 172 is positioned adjacent mandrel 162 with its open end exposed so that high pressure air emanating from chamber 166 entrains particulate material from tape 100 as described below. The entrained particulate material and carrier gas are then injected into plasma gun 174.

Plasma gun 174 is of conventional construction and uses an electric arc to heat and ionize inert gas from gas source 176 and regulator 178. The particulate material entrained in the carrier gas in conduit 172 is preferably introduced into the inert gas after it has passed through the electrodes to prevent coating the electrodes. However, the particulate material can of course be injected into the gaseous stream at any desired location. In some cases, all feed gas may be passed through conduit 172. In all cases, the granular material is heated with hot gas and accelerated to a high speed to form processed product 1.
Collision with 80.

As shown in FIG. 9, grooved film 102 of tape 100 is positioned adjacent bare mandrel 162. As shown in FIG. The knife 164 is arranged to cut the other film 104, as shown in FIG.
The lower edge of mandrel 162 has a lateral dimension d that is less than the width between weld lines 108 and 110 of film 102. That is, the tape 100 is attached to each roller 12.
6c around the bare mandrel 162, the knife 164 cuts the upper film 104. Due to the resistance of the blade 164 when cutting the film 104 and the reverse tension applied to the winding frame 100a, the tape film 102 is pushed around the mandrel 162 until it assumes the shape shown in cross section in FIG. 10 as it passes around the mandrel 162. It becomes flat against the surface. The particulate material is thus effectively stripped from the encapsulating tape 100 and entrained in the carrier gas entering the conduit 172.

Encapsulating tape 200 according to the modification shown in FIG.
The tape 100 is made up of a groove-shaped strip-shaped film 202 similar to the tape 100 and a flat strip-shaped film 204. Each film 202, 204 has a seam 20
6,208 and filled with granular material 210. However, the flat film 204 has a line 21
2 to substantially weaken the film 204. If desired, the score lines 212 may actually be perforations to facilitate separation of the film 204. The tape 200 is coated by the coating device 160
It can be used without making any changes other than removing the knife 164. Bare the tape 200 and remove the mandrel 162
When passed around the tape 200, the tension of the tape 200 forces the particulate material 210 outwardly against the film 204, causing the film 204 to rupture along the score line 212, rather than being cut by the knife 164 as described above.

From the foregoing description of the preferred embodiments of the present invention, those skilled in the art will appreciate that a unique and highly advantageous system for handling particulate materials for use in pulsating and continuous spray coating systems is provided. The device provides excellent control of the amount of material delivered to the combustion chamber and ensures control of the amount of material deposited on the workpiece. The quality of the coating applied to the workpiece is ensured since the coating is sealed within the encapsulating tape from the point of production of the granule material essentially to the point of introduction of this granule material into the combustion chamber.
Additionally, granular materials do not undergo particle size separation due to bulk handling. The particulate material is stripped from the encapsulating tape so that the tape material does not contaminate the coating. The device has a long service life because no valves are required in the pneumatic system after entraining the particulate material. The device provides precise control over the moment of introduction of granular material into the combustion cycle of a pulsating device, with the exact point of introduction being controlled by positioning the end of the injection tube within the combustion chamber, thus reducing particle size. Suitable for single application machines that apply particles with different melting points as a coating. Encapsulating tapes are easily made, and the precise amount of encapsulating particulate material per unit length of tape is easily controlled by simply filling the deformed tape with particulate material prior to welding the flat tape. The encapsulating tape can be made from an inexpensive plastic material such as polyethylene, a sealable plastic film material, or other suitable material.

Yet another tape 350 according to the present invention as shown in FIGS. 13, 14, 15 and 16.
consists of a relatively thick plastic film strip 362 and a relatively thin plastic film strip 364. Each film 362, 364 may be polyethylene or a similar plastic material, preferably heat weldable. Relatively thick film 362
defines a series of elongated pockets 366 extending laterally of the tape 350. Each pocket 366
has an arc-shaped cross section as shown in Figure 14.
5 and 16, it has a flattened end 366a. The effect of the arcuate cross-section of pocket 366 and flattened end 366a is shown by arrow 368 in FIG. 14 when flat film 362 of tape 350 is clamped between the inlet and outlet manifolds as described below. The objective is to form a structure that can withstand a broken frame under a pressure load applied in the direction indicated. A pair of T-shaped notches 370, 370 at the end 366a of each pocket 366 extend completely through the film 362 to form a pair of flaps. These flaps are indicated by arrows 368
The curvature of the arcuate portion of each pocket 366 normally resists movement in the opposite direction to retain the particulate material, although it opens when subjected to air pressure represented by . A relatively thin film 364 is sealed to a relatively thick film 362 by a heat weld extending around the entire circumference of each pocket 366 to form a capsule enclosing a quantity of particulate material.

The material selected for the thinner film 364 should be such that it will tear when rapidly blown with extremely high pressure air, but will not create fragments and will prevent any pieces of material from entering the fuel chamber. Polyethylene film with a thickness of about 0.0005 inches can be used for this purpose. The thicker film 362 may also be polyethylene on the order of 0.004 inches thick. The total width of the encapsulating tape 350 is
On the order of 0.375 inches, each pocket 366 is on the order of 0.280 inches long and 0.080 inches wide. pocket 3
Of course, the size and shape of 66 may vary over a wide range depending on the amount of particulate material to be injected during each combustion cycle, as discussed below.

As shown in FIG. 17, the exposed area 354 is
An outflow manifold 380 and an inflow manifold 382 are provided which together form a pneumatic stripping chamber 384 . The outflow manifold 380 has a short passage 386 leading directly to the combustion chamber as shown in FIG.
It is equipped with The inflow manifold 382 is raised to index the next capsule next to the enclosing tape 350 into the stripping chamber 384 and then lowered to index the next capsule next to the enclosing tape 350 into the stripping chamber 384 .
0 can be tightened around the periphery of each capsule as described below. A valve 388 directs high pressure air from the compressed air source 322 into the stripping chamber 384 . The injection ports 386 are constantly open to the combustion chamber.

Inflow manifold 382 defines a cavity shaped to closely receive each pocket 366, as shown in FIG. The outflow manifold 380 has a cavity shaped as shown in cross-section in FIGS. 17 and 18, and particles can freely circulate within the inflated capsule due to expansion of the outlet surface, and the capsule can be opened at the outlet 386.
It is designed to trap enough distension force to cause rupture at the top. The inlet manifold 382 has a pair of orifices 390, 392 located above the T-shaped notch 370 at the end of each capsule. Outflow manifold 380 includes a pair of mutually opposed shoulders 394';
394 to guide the encapsulating tape 350 as it passes through the exposed area.

In operation, the front portion of the encapsulating tape 350 is guided through the capsule detector and the stripping location 354, past an idler roller, and onto a take-up reel. When you are about to start coating, drive the take-up reel and remove tape 3.
50 begins to be pulled at a uniform rate through the exposed location 354. When the capsule detector detects the presence of a capsule or pocket 366, the sequence of events illustrated in FIG. 4 begins. When the pocket 366 is close to the exposed location 354, the inflow valve 1
6 opens as shown by time line 74. When valve 16 closes, igniter 2 is activated as shown by time line 76.
8 applies voltage to the ignition spark 30. As the valve 16 closes, the spark from the ignition bolt 30 causes the line 7 to
A pressure is created within the combustion chamber as shown by 2. The gently sloping portion 72a indicates the time period during which the pressure in the chamber increases due to the inflow of the fuel-air mixture through the valve 16, and the steeply rising portion 72b indicates the time period during which the pressure in the chamber increases due to the combustion of the mixture in this chamber. The slope represents the droplet pressure increase and the slope represents the time period for which the combustion gases are blown out through the nozzle 14.

Some time before the application of the ignition voltage, the inlet manifold 382 is moved downwardly to tighten the encapsulating tape.
As soon as the tape is tightened, the injection valve 388 is opened. Therefore, extremely high pressure air flows into orifice 3.
T
The flap formed by the glyph cut 370 is deflected to pressurize the pocket 366. This pressure causes thin film 364 to extend downwardly onto the underside of the exposed chamber formed by outlet manifold 380 and to
6. Stretch until it bursts. The turbulent air in the pocket 366 pushes all the particulate material into the pocket 3.
66, and the particulate material is pneumatically conveyed through passageway 386.

By resisting the arcuate pocket 366 from being crushed by the pressure applied to its top and by preferentially allowing pressure into the interior of the pocket 366 through the T-shaped notch, the two films 362, 364 are able to resist air flow. This makes it impossible to capture and hold particles during that time.
The very small volume of the cavity between the valve 388 and the exposed chamber ensures a very high response rate to the opening of the valve 388, thus injecting the particulate material 372 into the combustion chamber in a very short time. In this case, all particles are heated to some extent and propelled out of the combustion chamber at approximately the same velocity, ensuring high coating efficiency and improved coating quality.

Exposed area 41 due to the deformation shown in Figure 20
2 has a T-shaped cut 3 compared to the encapsulating tape 350.
A similar encapsulating tape 350a is utilized except that 70 is not provided. The exposed area 412 is substantially the same as the exposed area 354, and therefore each corresponding part is designated by the same reference numeral followed by the reference letter a. The only significant difference between location 412 and location 354 is that instead of a T-shaped cut, a piercing device 414 is provided to mechanically tear the end of each pocket of tape 350a. The piercing device 414 has a pair of sharp tips 4 bent downward.
14a and 414a. Each tip 414a
lowers the inlet manifold 382a and lowers the valve 388a.
Tightening tape 350a before opening pierces pocket 366a'. The arm-shaped configuration of each pocket 366a' and the particulate material provide sufficient crush resistance to allow each tip 414a to pierce relatively thick film. This structure prevents high-pressure air from crushing the upper film, allowing the pocket 366
a' to allow particulate material to be scavenged from the interior of pocket 366a' as described above with respect to FIG.

As shown in FIGS. 21 and 22, another encapsulating tape 420 according to the present invention includes a relatively thick strip of film 422 that is embossed to form a series of dome-shaped pockets 422a; A relatively thin film 424 seals a measured amount of particulate material 462 within 422a. The top of each domed pocket 422a is recessed to form a very thin section 422b. The thin portion 422b yields and perforates due to the high pressure applied to the surface of the dome before it collapses.

Encapsulating tape 420 is used in exposed locations such as location 354 with inlet manifold 430 and outlet manifold 432 shaped as shown in FIG. Each manifold 430, 432 includes a respective circular cavity 430a, 432a and an inlet orifice 430b and an outlet orifice 432b. When high pressure is applied through the inlet orifice 430b, the high pressure penetrates the thin recessed portion 422b and the pressure enters the interior of the pocket, inflating the lower film 424 downwardly until it ruptures above the outlet orifice 432b.

As shown in FIG. 24, another encapsulation tape 440 according to the present invention is similar to encapsulation tape 420 except that a series of score lines 442 are formed to facilitate the entry of high pressure into the top of the dome.

Around the periphery of the flat 464, the tape 450 has a notch 46 in place of the T-shaped notch 452 of FIG.
2 is formed. The effect of the pie-shaped flap formed by each notch 462 is that the T-shaped notch 452
is almost the same.

Although preferred embodiments of the present invention have been described above in detail, specific examples of the configuration of the present invention are summarized as follows.

(1) Using a heating chamber as the first chamber with an inlet for receiving the carrier gas flow and the particulate material and an outlet for directing the hot gas to the workpiece.
The device described in.

(2) The device described in the preceding paragraph (1), in which the stripping device is installed outside the heating chamber.

(3) the elongated tape has a plurality of separate capsules each containing a predetermined amount of particulate material, and the stripping device includes an inlet manifold having an inlet and an outlet manifold having an outlet communicating with the chamber; a source of air pressure higher than the pressure in the chamber and a pulse of air pressure at the inlet which passes through the capsule and into the chamber. The apparatus according to item (1), further comprising a first valve provided between the air source and the inlet for injecting particulate material into the air.

4. An apparatus according to claim 1, wherein the stripping device includes a piece for mechanically progressively opening the elongated tape before stripping the particulate material from the tape.

(5) The tape described in the preceding paragraph (4), in which the elongated tape is composed of at least two strips of film, and the part that mechanically opens the tape is composed of a part that separates the two strips of film. Device.

(6) The device according to the preceding paragraph (4), in which a piece that mechanically opens the tape is moved progressively to the exposed area.

(7) The device according to the preceding paragraph (4), wherein the part that mechanically opens the tape is composed of a part that distorts and ruptures the tape.

(8) A tape according to claim 2, comprising a strip of film joined along two seams to form a substantially continuous enclosed pocket.

(9) The tape according to item (8) above, wherein one of the band-shaped films is grooved to form a pocket.

(10) Claim 2 or (8) above, wherein one of the two sides of the pocket is weakened to make it easier to burst in a predetermined manner when subjected to a predetermined distortion force.
The tape described in (9).

(11) A series of equally spaced holes along at least one edge provides positive indexing for navigation through exposed areas. Or the tape described in any of the preceding sections (8) to (10).

(12) A series of equally spaced holes along at least one edge to provide positive indexing for navigation through exposed areas. The tape described in .

It goes without saying that the present invention can be modified in various ways without departing from its spirit.

[Brief explanation of the drawing]

Fig. 1 is a layout diagram showing a part of an embodiment of the coating device of the present invention in an axial section, Fig. 2 is a partial perspective view of an embodiment of the granular material-encapsulating tape of the present invention, Figs. 2a and 2b. 3A and 3B are plan views of different variants of the encapsulating tape of FIG. 2; FIG. 3 is an enlarged axial sectional view of the injection device of the coating device of FIG. 1 which utilizes the encapsulating tape of FIG. 2, and FIG. 4 is a time diagram showing the operation of the coating device of FIG. 1. 5 is an axial sectional view of a modification of FIG. 3, FIG. 6 is a perspective view of another embodiment of the encapsulating tape of the present invention, FIG. 7 is a block diagram of a coating device using the tape of FIG. 6, and FIG. The figure is a block diagram of another coating apparatus using the tape of FIG. 6. Figure 9 is an enlarged side view of the stripping location of the coating device in Figure 8;
The figure is a cross-sectional view taken along line 10-10 in Figure 9,
The figure is a plan view taken along line 11-11 in FIG. 10 in the direction of the arrow. FIG. 12 is a perspective view in cross section of a portion of another embodiment of the tape of the invention that can be used in the coating device of FIG. 7, and FIG. 13 is a plan view of still another embodiment of the encapsulating tape of the invention. 14 and 15 are enlarged sectional views taken along lines 14-14 and 15-15, respectively, in FIG. 13, and FIG. 16 is an enlarged perspective view of a part of FIG. 13.
Fig. 17 is an axial sectional view of the peeling location of another modification of Fig. 3, Fig. 18 is an enlarged sectional view of Fig. 17 along a plane orthogonal to the plane, and Fig. 19 is a different version of Fig. 18. FIG. 3 is an axial cross-sectional view shown in an operating state. 20 is an axial sectional view of a modification of FIG. 19, FIG. 21 is a plan view of still another embodiment of the encapsulating tape of the present invention, FIG. 22 is a sectional view taken along the line 22-22 of FIG. 23
24 is a partial perspective view of a variant of the tape of FIG. 21; and FIG. 25 is a still further variant of the tape of FIG. 21. Partial perspective view, Figure 26 is the 21st
FIG. 6 is a perspective view of a further variant of the tape shown; 10... Coating device, 12... Combustion chamber, 24...
Injection device, 40... Enclosing tape, 42, 48...
Sheet material (film), 44...pocket, 46
... Granular covering material, 52 ... Exposed area.

Claims (1)

[Scope of Claims] 1. In an encapsulating tape for delivering a predetermined amount of granular coating material to an exposed area where the granular coating material is exposed from within the tape, at least one seam so as to form a substantially continuous encapsulation pocket; at least one elongated strip of film bonded along the length of said encapsulation pocket, and a predetermined amount of granular coating enclosed within each unit length of said enclosing pocket to impart a hard surface coating to the workpiece when heated and impacting the workpiece at high speed. An encapsulating tape containing materials. 2. In an encapsulating tape that delivers a predetermined amount of the granular coating material to a pneumatic stripping site where the granular coating material is stripped from inside the tape by air pressure, the encapsulating tape is positioned at a predetermined distance from each other along the film body and each has a hard surface attached to the workpiece. A pair of extremely thin pneumatically rupturable strips of film bonded to each other to form a plurality of pockets filled with a predetermined amount of coating material to provide a coating; an encapsulating tape comprising a substantially thicker elongated support film defining a hole for receiving each filled pocket;