US3393658A

US3393658A - Spray system

Info

Publication number: US3393658A
Application number: US540874A
Authority: US
Inventors: Richard J Ott
Original assignee: Respond Inc
Current assignee: Respond Inc
Priority date: 1966-04-07
Filing date: 1966-04-07
Publication date: 1968-07-23
Anticipated expiration: 1985-07-23

Description

July 23, 1968 v R. .1. OTT v 3,393,658

SPRAY SYSTEM July 23, 1968 R. J. @TT 3,393,658

SPRAY SYSTEM Filed April 7, 1966 4 Sheets-Sheet 2 Wie/01@ J Mw, fi@ a/wk, //Mgl July 23, 1968 R, 1. OTT 3,393,658

SPRAY SYSTEM y Filed April '7, 1966 4 Sheets-Sheet 3 Zag 314 i @Mm ma@ www Magg R. J. OTT

SPRAY SYSTEM July 23, 1968 4 Sheets-Sheet t Filed April '7, 1966 3,393,658 Patented July 23, 1968 Uid Se@ Patent G 3,393,658 SPRAY SYSTEM f Richard J. Ott, Baroda, Mich., assgnor to Respond Inc.,

. Baroda, Mich., a corporation of Michigan Filed Apr. 7, 1966, Ser. No. 540,874

11 Claims. (Cl. 1181-7) .ABSTRACT OF THE DISCLOSUREy There is disclosed an apparatus for -sprayinga release agent onto dies in a die-castingA machine. The'apparatus includes a manifold structure carrying a plurality of spray guns and having internal passageways for release agent and air under pressure. The manifold structure is carried on the ends of the piston rod and-a guide rod for movement between retracted and advanced positions. Control means responsveto movement of the manifold are provided for controlling the flow of air and release agent.

from the mold. In addition to increasing the lost time during a production operation a stuck casting is frequently damaged while being removed from the die and must be scrapped. To increase production efficiency and to reduce the scrap rate itis a common practice to apply a releasing agent to the-dies or molds. The releasing agent lubricates adjoining surfaces of the mold andthe casting to prevent the casting from sticking to the mold.

A die or mold has a cavity Ain which the casting is formed. This die cavity commonly has a number of protuberances and indentations which give shape to a casting. The application of a releasing agent to all the irregular surfaces of the die cavityisusually accomplished by means of a manually actuated spray '.gun. To obtain complete coverage of the irregular die or mold surface the gun= is moved back and forth several times while being tilted at various angles to the surface ofthe die cavity. After the mold has been covered with releasing agent in this manner, the casting machine is actuated to continue the casting operation.

Due to variations in the movements of the spray gun operator, the manual Vapplication of releasing agent to a mold or die generally results in an uneven coating. Excess releasing agent is applied to parts of the die where the operator has moved the gun slowly. Conversely the coating of releasing agent will be skimpy and discontinuous at places where the spray gun is moved too rapidly. This uneven manual application of releasing agent to the mold results in increased production costs due to the sticking of castings where the coating is too skimpy. or interrupted. Production costs are further increased by the wasting of time and releasing agent by the spray gun operator as he applies the agent. This loss of time and releasing agent results from needless application of excess releasing agent to surfaces of the mold. Thus, the production efficiency of a highly developed die casting machine is greatly reduced by the manual application of releasing agent to the molds by means of a single spray gun.

The spray gun itself commonly has a nozzle for directing a stream of releasing agent onto the surface of the die. The nozzle is usually positioned adjacent to the hot dies, immediately after forming a casting, to spray the die for the next casting operation. Elastomeric seals in the nozzle soon deteriorate, due to the heat from the dies when the spray gun is used. Thus the efficiency of the prior art method of applying releasing agent to dies or molds is further reduced by the lost time required to periodically change the seals in the nozzle of the spray gun.

Therefore, one of the objectives of this invention is to provide a novel means for automatically spraying a releasing agent evenly and quickly onto a die or mold cavity.

Another object of this invention is toreduce the quantity of releasing agent applied to a die when spraying the die.

Another object of this invention is to provide a spray gun nozzle suitable for continuous use adjacent to a hot die.

Another object of this invention is to increase the production rate of die casting machines.

Another object of this invention is to provide a novel spray system to selectively apply a releasing agent to the irregular surfaces of a die cavity.

These and other objects and features of the invention will become more apparent from a reading of the following detailed description taken in combination with the accompanying drawings wherein:

FIG. 1 is an elevational view of a die casting machine embodying the invention;

FIG. 2 is a perspective view of the spray system utilized with the die casting machine of FIG. l; f

FIG. 3 is a fragmentary detailed sectional -view of the carriage or boom for the spray system of FIG. 2;

FIG. 4 is a fragmentary exploded view of the mounting means for the carriage in FIG. 3;

FIG. 5 is a fragmentary sectional view taken along the line 5-5 of FIG. 2;

FIG. 6 is a perspective view of a spray gun;

FIG. 7 is a fragmentary sectional view taken along the line 7-7 of FIG. 6; and

FIG. 8 is a schematic drawing of the control system for the spray assembly.

Referrng now to the drawings in greater detail, there is shown in FIG. 1 a die casting machine 10 of a conventional construction. The die casting machine 10 includes a stationary die or mold 12 and a movable die 14 which cooperates with the stationary die 12. During the die casting operation, the two dies 12 and 14 `are forced together by a hydraulic toggle mechanism 16. The toggle mechanism 16 will retain the

dies

12 and 14 in an abutting relationship. Molten metal is forced between the two abutting dies 12 and 14 by means of a shot mechanism 18 which fills the mating die cavities with a suitable metal for forming a casting. The construction of the die casting machine 10, and the operation of the shot mechanism 18, is well known and does not per se constitute a part of this invention.

After an object has been cast between the two

dies

12 and 14, the toggle mechanism separates the dies and the casting is removed. As previously explained, the hot casting tends to adhere to the surface of the

dies

12 and 14. To facilitate the removal of the casting from the dies, a suitable releasing agent is applied to the surfaces of the die cavities. A spray assembly 20 is utilized to apply the releasing agent to the surfaces of the

dies

12 and 14, so that the cast object can be readily removed from the dies.

Referring now to FIG. 2, the spray assembly 20 is fastened to the tie bars 22 `and 24 of the die casting machine 10 by means of a support frame 26. The support frame 26 includes two vertically extending support bars 2S and 30 which are interconnected by

end plates

32 and 34. The support frame 26 is connected to the tie bars by means of movable connection assemblies 36 and 38. The connection assemblies are attached to the tie bars 22 and 24 by

roller chains

40 and 42. The

roller chains

40 and 42 are secured to the

connection assemblies

36 and 38 by the nuts 47 and bolts 48. When the nuts 47 and roller chains are loosened the support frame 26 can be moved horizontally to adjust the position of the spray assembly relative to the dies 12 and 14. It will also be apparent that the

adjustable roller chains

40 and 42 permit the spray assembly to be easily connected to die casting machines having tie rods of different diameters.

' The

connection assemblies

36 and 38 include sliding

plates

44 and 46 which are positioned intermediate the support bars 28 and 30. Backing

plates

50 and 52 are fastened, by welding or other means, to the sliding

plates

44 and 46. V-

blocks

54 and 56 are connected to the

backing plates

50 and 52 by the bolts 60 and nuts 62. When the nuts 62 are tightened, the V-

blocks

54 and 56 will clampingly engage the support bars 28 and 30. By loosening the nuts 62 the support frame 26 can be moved up and down to vary the vertical position of the spray assembly 20 relative to the dies 12 and 14. This vertical adjustment f also permits the spray assembly to be used with die casting machines having tie bars spaced apart by various distances.

From the foregoing remarks it is apparent that the support frame 26 can be utilized to connect the spray assembly 20 to any desired die casting machine. The

roller chains

40 and 42 enable the

connection assemblies

36 and 38 to engage tie bars of various diameters on different die casting machines. Since the support bars 28 and 30 may be adjusted vertically, relative to the connector blocks 36 and 38, the support frame 26 may also be attached to die casting machines having tie bars spaced apart by various vertical distances. If the spray assembly is to be used with a die casting machine which does not have tie bars, simulated tie lbars may be utilized for mounting the support frame 26 on the die casting machine. This is done by the use of suitable cylinders which are securely connected to the die casting machine and act as substitute tie bars for mounting the spray assembly. Thus, the support frame 26 may also be connected to a die casting machine of a type which does not utilize tie bars.

The spray assembly 20 is mounted on a main frame 64 which is adjustably fastened to the support bars 28 and 30 by means of the

bolts

66 and 68 which engage the

slots

70 and 72 in the side of the main frame 64. The

slots

70 and 72 permit the main frame to be adjusted horizontally relative to the support bars 28 and 30. From an examination of FIG. 4, it will be apparent that the main frame 64 is advantageously made up of two identical support beams 76 and 78. The support beams are separated by a central slot 80 which provides, as will be explained in greater detail subsequently, a means for mounting the drive mechanism for the spray system on the main frame 64.

v Referring now to FIG. 3, the drive mechanism includes an air cylinder 82 which is connected to the main frame 64 by means of bolts 84 which extend through the central slot 80 between the two

support beams

76 and 78. The air cylinder 82 has an outer end plate 86 and an opposite inner end plate 88 for closing the ends of the air cylinder 82. The two

end plates

86 and 88 are clamped in a rm sealing engagement with the air cylinder 82 by means of tie rods 90. A piston 92 is slidable within the air cylinder 82 from a position adjacent the rear end plate 88 to a position adjacent the forward end plate 86. A carriage assembly 94 is connected to the piston 92 by means of a connecting rod 96. It will be apparent that forward and rearward movement of the piston 92 will also move a carriage assembly 94 relative to the air cylinder 82 and main frame 64. The carriage assembly 94 is guided for forward and rearward movement by means of a support- 4 ing guidebar 98 which slides in a casing or cylinder 100 positioned immediately below the air cylinder 82.

The carriage assembly 94 includes a releasing agent or coating uid maniflold 102 and an air or carrier fluid manifold 104.

Spray guns

106 and 108 are connected to the

manifolds

102 and 104 by connections which will `be explained in greater detail subsequently. When the carriage assembly 94 is moved forwardly, by the connecting rod 96 and piston 92, the spray guns V106 and 108 will be positioned adjacent to the two `dies 12 and 14 of the die casting machine 10. A cam rod 110 is connected to the

manifolds

102 and 104 and is moved forwardly with the spray guns 106 and 10S. The cam rod 110l is guided by means of a guide block 112 which is supported by the guide cylinder 100. The cam rod 110 has a plurality of cam members' 114 mounted in a slot 115 in the cam rod 110. The cam members 114 may, by loosening the connecting bolts 116, be adjusted relative to the cam rod 110. The cams 114 actuate a limit or sensing switch 118 which is fastened by a bracket to the end plate 86 of the air cylinder 82. The limit switch 118 is connected by suitable electrical leads 122 to a main control box 124 which is mounted on an outer end of the main frame 64 (see FIG. 1).

The mainv control box 124 coordinates and controls the movements of the carriage assembly 94 and the actuation of the

spray guns

106 and 108 by means of control valves and switch mechanisms. When the

spray guns

106 and 108 are 'actuated a coating fluid or releasing agent is applied to the dies. The releasing agent is supplied, under pressure, to the spray assembly 20 4by means of a suitable fluid passage or conduit 126 which is connected to a pressurized source of releasing agent 128 (see FIG. 8). A normally closed releasing agent solenoid valve 130 (see FIG. l) is connected to the conduit 126 and a conduit 132 which extends from the solenoid valve 130 to the releasing agent manifold 102. The solenoid valve 130 controls the low of releasing agent between the conduit 126 and the releasing agent manifold 102.

The solenoid valve 130 is connected to the main co'ntrol box 124 by means of a suitable electrical connection 134. When the limit or sensing switch 118 is actuated by one of the cams 114, the normally lclosed solenoid Value 130 will be opened to enable the releasing agent or coating fluid to flow through the conduit 132 to the releasing agent or coating fluid manifold 102. The releasing agent or coating Huid is conducted from the manifold 102 to the

spray guns

106 and 108 by the connecting conduits or

hoses

136 and 138. As will be explained in greater detail subsequently, when the sensing switch 118 is actuated by one of the cams 114 the

spray guns

106 and 108 will be in a spray position, relative to the dies 12 and 14. The opening of the solenoid value 130 will then allow the pressurized releasing agent or coating fluid to be conducted to the

spray guns

106 and 108 onto the dies at the predetermined spray location.

When the

spray guns

106 and 108 are not in a spray position, they will not spray releasing agent or coating uid onto the dies since the supply of releasing agent is cut olf by the closing of solenoid valve 130. Thus, the cams 114, which actuate the limit or sensing switch 118 when the spray guns are in a spray position, permit the spray assembly to only spray the dies with releasing agent at predetermined locations. It will be apparent that this feature will reduce production costs by reducing the wastage of releasing agent or coating liuid.

The carriage assembly 94 is moved into the spray position, relative to the dies 12 and 14, by the piston 92 which is forced forwardly by `air pressure on a rear surface 140 of the piston. The piston 92 and spray carriage assembly 94 are moved rearwardly by air pressure on a forward surface 142 of the piston. High pressure air, to move the piston 92, is conducted to the aircylinder 82 from a suitable source 143 by means of the pipe or conduit 144. The pipe orconduit 144 is connectedvto the air supply control valve146 by means of a T-connection 148 and conduit 150. -In a manner to l:be .explained in greater detail subsequently, the control valve 146 selectively `directs the airpressure into either the conduit or air hose 152 which is connected vtohthe rear of the air cylinder 82 or the conduit 154 which is connected to the forward end of the air cylinder 82. It will be apparent that when the control valve -146 directs the high pressure air through the conduit 152 to the rear of the air cylinder 82, the piston 92 will be forced forwardly by air pressure on the rearsurface 140 of the piston. When the air is conducted through the conduit 154 it will be directed against the forward surface 142 of the piston 92 to move the carriage assembly and piston rearwardly relative to the main frame64. t

The air control valve 146 is a two-way valve which is actuated by means of a solenoid 156 which is connected to the main control box 124 by a suitable electrical connection 158. When the air control valve 146 isactuated to direct the high pressure air through the conduit 152 to the rear of the piston 92, the conduit l154 lwill be connected to an exhaust port 160.` Thus, the air between the forward surface 142 of the piston and the end plate 86 of the air cylinder 82 will be returned to the air control valve 146 -by the conduit 154 and exhausted to the atmosphere through the exhaust port 1.60. When the forward portion of the cylinder is at the relatively low exhaust or atmospheric pressure, the piston 92 will move forward under the force of the high pressure air against the rear surface 140y of the piston. When the air control valve 146 is returned to its normal or unactuated position, the conduit 152 will be connected to the exhaust port 160. The high pressure air, from the conduit 150', will then be directed through the conduit 154 to the forward end of the air cylinder 82 to apply air pressure against the forward surface 142 of the piston. The high pressure air on the forward sur-face 142 of the piston will force the piston and carriage assembly `94 rearwardly to the return or starting position. The air between the rear surface 140 of the piston 92 and the end plate 88 will be conducted, through the conduit 152, to the exhaust port 160 to permit the piston 92 to move rearwardly.

The rate of movement of the carriage assembly, relative to the main frame 64, is controlled by means of a throttle valve 164 and a normally open speed control valve 166 (see FIG. 8). The forward end of the air cylinder 82 is connected to the throttle valve 164 by

air conduits

168 and 170. The air cylinder is also connected to the speed control valve 166 by means of a conduit 172. It will be apparent from an examination of FIG. 8 that the speed control valve 166 and throttle valve 164 are connected in a parallel relationship by means of the

conduits

174 and 176.

The adjustable throttle valve may be set to permit a predetermined quantity of return air to flow through the

conduits

170 and 176 to the return conduit 154. When the normally open speed control valve 166 is actuated to the closed position, it will be apparent that the setting of the throttle 164 will regulate the rate of ow of return air, and therefore the speed with which the piston 92 can be driven forward by the high pressure air on the rear surface 140 of the piston. The throttle valve 164 is set to restrict the flow of return air from between the forward surface 142 of the piston 92 and the end plate 86 of the air cylinder 82. The resulting low piston speed, as will be explained in greater detail subsequently, corresponds to a relatively slow spray speed. Thus, the carriage assembly 94 will, when the speed control valve 166 is closed, move forwardly at a relatively slow speed to permit the

spray guns

106 and 108 to thoroughly coat the dies with the releasing agent or coating uid.

When the carriage assembly 94 is being returned to its original position after spraying the dies, and during the non-spray forward movement of the carriage assembly,

tha-t is when the cams 114 are not in actuating contact with the sensing switch 118, the carriage assembly is moved at a relatively high traverse speed. When the carriage is moving at this relatively high traversespeed, the speed control valve 166 is open to enable the return air to flow through the

conduits

172 and 174 to the return conduit 154. It will be apparent that when the speed cont-rol valve 166 is open the return air can be conducted from the forward part of the air cylinder 82 at a much greater rate. Therefore, the ,piston 92 will move forward at a higher speed under the force of the high pressure air on the rear surface of the piston 92.

From the foregoing remarks, it will be apparent that the rate of movement of the carriage assembly 94 is controlled by regulating the llow of return air from the cylinder 82. When the flow of return air from the cylinder 82 is restricted by the adjustable throttle valve 164 and the speed control valve 166 is closed, the carriage assembly will move at a relatively slow spray speed. When the speed control valve 166 is open, the flow of return air will, to some extent, bypass the throttle valve 164 so that the carriage assembly 94 will move at a relatively high traverse speed. Thus, the time required for a spray cycle is held to a minimum by enabling 'the carriage to move at a first relatively high speed to the spray position, then reducing its rate of forward movement during the spray operation. After the dies have been sprayed the carriage is returned to its initial position at the relatively high traverse speed.

To coordinate the rate of movement of the carriage 94 with the position of the

spray guns

106 and 108 relative to the dies, the speed control valve 166 is actuated by the closing of the limit or sensing switch 118 by the cams 114. The cams 114 are positioned on the cam rod 110 at predetermined locations so that the carriage and spray guns will be in a spray position relative to the dies when the sensing switch 118 is actuated. As previously explained, the closing of the sensing switch 118 also actuates the normally closed releasing agent solenoid valve 130. Thus, the closing of the sensing switch slows the rate of movement of the carriage 94 from the traverse speed to the spray speed While simultaneously opening the releasing agent solenoid valve 130 to enable releasing agent to be conducted to the

spray guns

106 and 108.

In addition to supplying air for moving the carriage assembly 94, the air conduit or hose 144 conducts air to a normally closed spray air supply control valve by a conduit 182. The spray air supply control valve 180 is connected to the air manifold 104 by a conduit 184. When the normally closed spray air supply control valve 180 is opened, high pressure air will ow from the conduit 144 through the valve to the manifold 104. As will be explained in greater detail subsequently, the air will then flow from the manifold 104 to the

spray guns

106 and 108 to entrain the releasing agent or coating uid for application to the dies. The actuation of the spray air supply control valve 180 is controlled by the solenoid 186 which is connected to the main control box 124 by the electrical connector 188. When the air supply valve 186 is in its normal or closed position, the air manifold 104 will not be pressurized and the spray guns 106 and 1108 will not napply coating fluid or releasing agent to the ies.

The actuation of the releasing agent flow control solenoid valve 130, the air supply control valve 146 and the spray air supply control valve 180 are all coordinated by the main control box 124. The main control box 124 senses the position of the carriage assembly 94 relative to the main frame by means of the sensing switch 118 which is connected to the main control box by the electrical leads 122. Referring now to FIG. 8, the main control box 124 is supplied with power by

lines

190 and 192 which are connected to

terminals

196 and 198 of a terminal block 194. To begin the spray cycle a start switch, not shown, is actuated by the operator of the die casting machine. The start switch is connected by means of

leads

200 and 202 to the

terminals

204 and 206 of the terminal block 194. A timer 208 is connected to the power line 190 by means of a lead 210 which is connected to a terminal 211 of the timer and terminal 212 and terminal block 194. Terminal 214 of the timer 208 is in turn connected to the limit switch 118 and air supply control valve 146 by means of the leads 216, 218 and 220. The terminal 214 of the timer is also connected to a terminal 222 of a selector switch 224 by a lead 226. It will be apparent that actuation of the timer 208, to interconnect terminals 211 and 214, is necessary to complete the circuit from the power line 190, through the solenoids for the control valves to the power line 192.

The timer 208, of a known construction, may be set for any predetermined time, during Iwhich the terminal 211 will be connected to the terminal 214 by the timer switch 230. At the end of the predetermined time, the timer 208 will open a switch 230 so that the terminal 214 is no longer connected to the terminal 211. When the switch 230 is opened, the various control solenoids will be released and the control valves will 'be returned to their normal position.

The limit or sensing switch 118 is connected by the

leads

232, 234 and 236 to the releasing agent supply control valve 130. The releasing .agent supply control valve 130 is in turn connected by the lead 240 to the power line 192 through

terminals

228 and 198 of the terminal block 194. Actuation of the normally open limit switch 118, will close the circuit between the two power leads 190 and 192 to actuate the releasing agent control valve 130.

The limit switch 118 is connected by means of

leads

232 and 241 to the carriage speed control valve 166. The carriage speed control valve 166 is connected to the terminal 238 of the terminal block 194 by means of the

leads

242 and 248. The limit Switch or sensing switch 118 is also connected to the spray air supply control valve 180 through the selector switch 224 by means of the

leads

232, 234, 250 and 252. The leads 250 and 252 are interconnected, at the selector switch 224, by means of the switch bar 254 and the

contacts

256 and 258. When the selector switch is moved to the left the limit switch 118 `will be connected to the spray air supply control valve 180. The spray air supply control valve 180 is also connected to the power line 192 by means of the

leads

260 and 248.

The above circuitry interconnects the components of the spray assembly so that closing of the limit switch 118 by the calms 114 will simultaneously cause the a-ctuation of the liquid solenoid valve 130, the spray air supply control valve ,180, and the cylinder speed control valve 166. Since the cams 114 have a length corresponding to the duration of a spray period and are located :to actuate the switch when the spray guns are in a spray position, it lwill be apparent that the closing of the limit switch will occur only at spray positions for :a predetermined spray period. During the spray period releasing agent will be supplied to the

spray guns

106 and 108 through the actuated releasing agent control valve 130. High pressure air will simultaneously be supplied to the guns by the actuation of the spray air supply control valve 180. The speed control valve 166 is closed so that the carriage travels at a relatively slow rate during the spray period. The limit or sensing switch 118, by sensing the positioning of the carriage assembly in a predetermined spray position, coordinates the conducting of releasing agent and the air to the

spray guns

106 and 108 while simultaneously reducing the rate of travel of the carriage assembly 94.

The air supply control valve 146 is connected to the timer 208 by the leads 216 and 220. The air supply control valve 146 is also connected to the power line 192 by means of the leads 264 and 248. Thus, the air Supply control valve 146 will be actuated to supply high pressure air against the rear surface of the piston 92, through the conduit 152 whenever the timer switch 230 is closed. When the timer switch 230 opens, at the end of a predetermined time the air supply control valve` 146 will be released .and the carriage 94 will be returned to its normal position by high pressure air which will be connected to the forward end of the air cylinder 82 by means of the return air conduit 154.

When the selector switch 224 is placed with the selector bar 254 between

contacts

266 and 222, that is with the selector switch moved to the right of the position shown in FIG. 8, the spray air supply control valve will be connected to the power line through the

leads

252, 226 and 210. Since the other side of the spray air supply control valve 180 is connected directly to the power line 192 -by the

leads

260 and 248, the spray air supply control valve 180 will be continuously actuated when the timer 208 is closed. Thus, a continuous stream of air will ow out of the

spray guns

106 and 108. The releasing agent or coating fluid will -be controlled by the solenoid 130 which is actuated in response to the limit switch 118 sensing a spray position. The continuous flow of air, when the selector switch is across

contacts

266 and 222, will cool the hot -dies while the carriage assemly is moving at the relatively high traverse speed to a spray position. When an intermittent air supply is desired, the selector switch 224 may be moved across

contacts

256 and 258, so th-at the sensing or limit switch 118 must be actuated in order to complete the circuit through the spray air supply control valve.

Referring now to FIGS. 3, 6 and 7, high pressure air is supplied to the

spray guns

106 and 108 through the air manifold 104. The

spray guns

106 and 108 are connected to the air manifold 104 by means of a universal mounting 270. The universal mounting 270 is connected to the -manifold 104 Iby a' threaded connector tube 272 which is screwed into an aperture 274 in the manifold. The threads 276 on the connector tube 272 mate with threads on the interior of the aperture 274. When the connector tube 272 has been threaded into the aperture 274, a jam or lock nut 278 is tightened to secure the connector tube 272 in position. A fitting or elbow 280 is fastened to the opposite end of the connector tube 272. A second, upwardly directed, connector tube 282 is connected to the fitting 280 and is threaded into an aperture 283 in the body member 284 of the spray gun. The connector tube 282 is locked into position by means of the jam or lock nut 288. A channel or passage 290 is provided in the center of the

connector tubes

272 and 282 and the fitting 280. The channel 290 will conduct high pressure air from the manifold 104 into the body 284 of the spray gun.

The spray gun may be pointed in any desired direction by adjusting the universal connection 270. It will be apparent that the spray gun, as shown in FIG. 6, may be pointed downwardly by pivoting the universal connection 270. The universal connection 270 is pivoted, relative to the manifold 104, by loosening the jam or lock nut 278 and turning the connector tube 272 in the threaded aperture 274. When the spray gun is pointed in the desired direction, the lock nut 278 is tightened to retain the connector tube 272 and the spray gun in the desired position. In a similar manner, the spray gun may be adjusted to point in any horizontal direction, as viewed in FIG. 6, by loosening the lock nut 288 and moving the body member 284 on the threaded end portion of the connector tube 282. When the spray gun has been pointed in the desired horizontal direction, it will be apparent that it can be locked in that position by merely tightening the lock or jam nut 288.

As is best shown in FIG. 7, the spray gun includes a forward nozzle member 292 which is connected to the body 284 by means of threads 294 in the end portion of the nozzle. The threads 294 mate Withthreads 296 on the interior of an aperture 298 in the body member 9 284. The nozzle 292 includes a frustoconically shaped mouth or orifice 300 which has a base portion 302 and a head portion 304. A channel or passage 306 is connected to the head portion 304 of the mouth 300. A cylindrical chamber 308 is defined by a side wall 310 connected to a base wall 312 and the base 302 of the frustoconical orifice 300 of the nozzle 292. From an inspection of FIG. 7, it will be apparent that air from the manifold 104 will flow through a passage 290 to the chamber 30S. The air will then flow through the base 302 of the nozzle 292 to the channel 306. When the air flows from the frustoconically shaped mouth or orifice 300 into the channel 306, a releasing agent will be entrained in the air in a manner to be explained in greater detail subsequently.

The spray gun is supplied with releasing agent, as previously explained, by the conduit 136 which is connected to the releasing agent manifold 102. The releasing agent will flow from the conduit 136 through a valve 314 into a chamber 316 in the body member 284 of the spray gun. The releasing agent chamber 316 is connected to -an expansion tube 318 by means of the nozzle or orifice 320. The nozzle or orifice 320 is frustoconical in shape and has a head portion 322 connected to the chamber 316 and a base portion 324 abutting the expansion -tube 318. It will be apparent that the releasing lagent will fiow through the tube 136 and the valve 314 into the chamber 316. The pressurized releasing agent will then flow from the chamber 316 through the head 322 of the nozzle or orifice 320 into the expansion tube 318. Since the nozzle 320 is frustoconical in shape, the releasing agent will tend to atomize when it flows from the chamber 316 to the expansion tube 318 through the nozzle 320. The atomized releasing agent will fiow through the tube 318 into the channel 306 inthe nozzle 292. The atomized releasing agent will be entrained, in the channel 306, in the air flowing from the chamber 308 through the nozzle 292. The entraining of the releasing'agent, in the -air which acts as a carrier fluid, is facilitated by an expansion area 330 in the end portion of the tube member 318. v

The valve 314 includes a ball check 332 which is seated against the conduit fitting 334 by the spring 336. The pressure exerted on the ball check 332 by the spring 336 can be varied by turning the adjustment screw 338. When the adjustment screw 33-8 is turned `downwardly the spring will exert a greater pressure seating the ball check on the fitting 334. Similarly, if the' adjustment screw 338 is unscrewed or turned upwardly, the spring 336 will exert less pressure on the ball check 332. When the adjustment screw 338 has been positioned to give the desired seating force on the Iballcheck 332, the jam or lock nut 340 is tightened to retain the adjustment screw in the desired position.

If the pressure on the releasing agent or fluid coating in the conduit 136 is insufficient to overcome the spring pressure on the ball check 332, it will be apparent that the valve 314 will prevent the -releasing agent or coating fluid from flowing into the chamber 316. Thus, the flow of the releasing agent, through the spray gun, will be controlled by both the valve 314 and the releasing agent control solenoid valve 130. The spray gun may also be utilized with ya system which does not supply releasing agent or coating fiuid under pressure. When used with suc'h a system the adjustment screw is positioned to apply a very light pressure on the ball check 332. When this is done air flowing through the nozzle 292 will draw or Siphon the releasing agentfromthe chamber 316 and the conduit 136 through the expansion tube 318. The siphoned releasing agentor coating fluid will be entrained in the high pressure air, flowing aroun-d the expansion tube 318, in the manner previously explained for a system utilizing apressurized source of releasing agent or coating fiuid.

The spray gun, as will be seen in FIG. 7, does not require the use of any elastomeric seals in order to obtain a fluid tight connection between the various components of the spray gun. The Aexpansion tube 318 is forced into a 10 circular aperture 342 in the' body member 284. The. various other threaded connections are all tightened to form a seal so that they do not leak. Since there are no elastomeric seals in the spray gun, it will be apparent that the gun may be utilized in a relatively hot environment for a long period of time. Thus, the heat from the dies 12 and 14 of the die casting machine 10 willnot, after a relatively short period of use, cause leaks at the joints between the components of the

spray guns

106 and 108.

For purposes of affording a more complete understanding of the invention, it is advantageous now to provide a functional description of the mode in which the component parts thus `far identified cooperate. The spray assembly support frame 26 is clamped to the tie bars 22 and 24 of the die casting machine 10. The main frame 64, which is connected to the vsupport frame 26, positions a carriage assembly 94 adjacent to the dies 12 and 14 of the die casting machine 10. The support frame 26 can be adjusted vertically, by means of the

connection assemblies

36 and 38 to position the

spray guns

106 and 108 adjacent to the center of the die. The two

slots

70 and 82 enable the main frame 64 and spr-ay guns to -be adjusted horizontally relative to the dies 12 and 14.

`When a suitable starting switch, not shown, is actuated, the air supply control valve 146 will be actuated to connect air from the high pressure air supply conduit 144 to the conduit 152. The conduit 152 is connected to the rear end the air cylinder 92 so that the high pressure air will force the piston 92 to move forwardly in the cylinder 82. The return air, from the forward end of the cylinder 82 will then ow through the

conduits

168, and 172 to the speed control valve 166 and throttle valve 164 (see FIG. 8) and into the return air conduit 154. When the two-way air supply control valve 146 was actuated to connect the high pressure air to the conduit 152, the return air con-duit 154 was connected to the exhaust port 160 of the control valve. Thus the .return'ai'r will ow from the return air conduit through the exhaust port into the atmosphere `as the piston moves forward.

The carriage assembly 94 and the piston 92 will move forwardly until the spray guns 106 and 608 are adjacent a portion of the dies which is to be sprayed. When this predetermined spray position is reached, the sensing switch 118 will 4be actuated or closed by contacting a cam 114. When the switch 118 is closed, the speed control valve 166 will be closed to block the flow of air from the conduit 172 to the conduit 174. The return air from the air cylinder 82 will then be able to fiow only through the throttle valve 164. Thus, the rate of forward movement of the piston 92 and the carriage assembly 94 will be reduced and the carriage will slow down to a predetermined spray speed which can be adjusted by means of the throttle valve 164.

In addition to reducing the rate of forward movement of the carriage assembly, the closing of the limit switch 118 actuates the releasing agent or coating fiuid control valve 130 to enable the pressurized releasing agent or coating fiuid to flow through the

conduits

126 and 132 to the releasing agent manifold 102. The pressurizedreleasing agent or coating fiuid will flow from the manifold 102 through the

conduits

136 and 138 to the

spray guns

106 and 108. Simultaneously with the actuation of the releasing agent control valve 130 a spray air supply control valve will be actuated by the closing of the sensing switch 118. When the spray air supply control valve 180 is actuated, high pressure air will then fiow through the

conduits

144 and 184 to the air or carrier fluid manifold 104.

The air or carrier fluid manifold 104 is connected to the

spray guns

106 and 108 through the passages 290 in the universal mounting 270. The releasing agent or coating fiuid will be entrained in the high pressure air or carrier fiuid in the nozzle 292 of the

spray guns

106 and 108. The entrained releasing agent will be sprayed onto the dies 12, 14 by the

spray guns

106 and 108. It should be realized that while only two

spray guns

106 and 108 have been shown, it is contemplated that any desired number of spray guns can be connected to the air manifold 104 by removing plugs 400 and mounting air guns in the apertures in the air manifold 104. Similarly, plugs 402 are provided for apertures in the releasing agent manifold 102. Thus, additional releasing agent conduits, similar to 132 and 136, could be connected to the added spray guns to conduct releasing agent from the manifold 102 to the spray guns.

When the cams 114 are moved out of contact with the sensing switch 118, the carriage assembly will have moved past the spray position and the sensing switch will open, When the sensing switch 118 has opened, the releasing agent control valve 130 and spray air supply control 180 will be closed. Thus, the

spray guns

106 and 108 will, when the carriage assembly 94 moves past the spray position, stop spraying releasing agent on the dies 12 and 14. Simultaneously with the release of the

control valves

130 and 180, lthe speed control valve 166 will be opened. The return air, from the air cylinder 82, will then flow through the

conduits

172 and 174 to enable the piston 92 to travel at a higher forward speed in the air cylinder 82. The carriage assembly 94 will continue to move at this relatively high traverse speed until the limit switch 118 again contacts a projecting cam 114.

It will be apparent that the duration of the spray period of any given spray position will be determined by the length of the cam 114. Since the cams 114 may be of any desired length, the spray period at each of the spray positions may be of any desired duration. The cams 114 are also independently adjustable longitudinally on the cam rod 110 to vary the location of a spray position relative to the dies 12 and 14. Thus, the spray positions may be adjusted so that the

spray guns

106 and 108 will apply the releasing agent to die cavities having any shape in accordance with the object to be cast.

A timer 208 is connected to the air supply control valve 146. When the timer indicates that a predetermined time period has elapsed, the timer will open to break the circuit retaining the air spray control valve 146 in open or forward position. The air supply valve 146 will, when the timer 208 breaks the circuit, be actuated to connect the forward air supply conduit 152 to the exhaust port 160 and the rearward air supply conduit 154 to the source 143 of high pressure air. The high pressure air will then travel through the

conduits

154, 174 and 176 and the throttle valve 164 and speed control valve 166 to the forward end of the air cylinder 82. The high pressure air will contact the forward surface 142 of the piston 92 to move the piston rearwardly in the air cylinder 82. rlChe piston 92 will return to the original or starting position adjacent to the end plate 88 of the air cylinder 82 until the next spray cycle. The carriage assembly, in the original or starting position, will be spaced apart from the dies 12 and 14 so that the die casting machine can bring the two dies together for a die casting operation.

A continuous flow of spray air, through the control valve 160 may be applied to the air or carrier fluid manifold 104 by placing the selector switch 224 across

contacts

222 and 266. When the selector switch is in this position a continuous stream of cooling air will be applied to the surface of the hot dies on both the outwardly and inwardly movements of the carriage assembly 94. When the selector switch 224 is placed across

contacts

256 and 258, the spray air supply control valve 180 will be actuated, as previously explained, when the sensing switch 118 is closed by the cams 114. Thus, with the selector switch in this positionthere will be an intermittent flow of carrier fluid or air from the

spray guns

106 and 108 at only the spray position when the coating fluid or releasing agent will be entrained in the air by the spray guns.

The spray guns, which may be of any desired number by merely mounting additional guns in place of the plugs 400 in the air manifold 404, are connected to the air manifold 104 by means of a universal mounting 270. The universal mounting permits the guns to be pointed in any desired direction to provide an optimum angle of contact for the stream of air-entrained releasing agent to contact the dies 12 and 14. It will be apparent that this feature is particularly useful with a deep die having angled surfaces.

The spray guns are made of metal parts which are heat resistant. The heat from the hot dies will not therefore deteriorate the joints between the components of the spray gun. Thus, the spray guns can be utilized for a relatively long period of time without replacing any of the component parts. f

Although the preferred embodiment of the invention has been shown with a carriage mounted in a horizontal position, it -Will be apparent to those skilled in the art that the spray assembly could be mounted with the carriage assembly in the vertical position. Also, while a fluid releasing agent has been found to be most satisfactory for most applications to dies, it is contemplated that a powdered releasing agent `could be used with the spray assembly. In addition to these modifications, it will be apparent to those skilled in the art that the spray will have applications in environments other than die casting. Thus, a coating fluid, other than a releasing agent, could be applied by the

spray guns

106 and 108 to a given object. The spray guns are capable of entraining any desired coating fluid in a given carrier fluid.

In view of the foregoing remarks, it shoul-d be understood, that the invention is not limited to the particular embodiment shown. These and many other modifications may be made; and it is, therefore, contemplated to cover by the appended claims any such modifications as fall within the spirit and scope of the invention.

What is claimed is:

1. An apparatus for applying a lrelease agent to dies in a die-casting mac-hine comprising a frame mountable a'djacent a die-casting machine, manifold means including a first portion connectable to a source of release agent and a second :portion connectable to a source of air under pressure, spray gun means mounted on said manifold means and connected to said release agent portion and said air portion, a pair of parallel space-d apart elongated rod-like members `reciprocably mounted on said frame and connected to and supporting said manifold means for movement between a retracted position and advanced spraying positions laterally outwardly from said frame and adjacent said dies, drive means connected with one of said members for selectively advancing and -retracting said members and said manifold means, an elongated cam support member parallel to said rod-like members and connected for movement in unison with said manifold means, cam means on said cam support member, and control means for controlling said drive means and flow of release agent and air to said manifold means and including a sensor mounted on said frame and engageable with said cam means.

2. An apparatus, as defined in claim 1, wherein said cam means includes a plurality `of independently adjustable cams, each of said cams representing a predetermined spraying position, and said sensor comprises a single sensing switch actuated by said cams upon movement of the manifold means to said predetermined spraying positions.

3. An apparatus, as defined in claim 2, wherein said switch is a double acting switch -responsive to b-oth advancing and retracting movements of the manifold means.

4, An apparatus, as defined in claim 1, wherein said control means includes an air control valve connected between the source of air under pressure and said air rportion of the manifold means, a valve control connected to said valve to actuate the valve from a first closed position to a second open position, and selector means connected to said valve control and actuatable from a first selector position to a secondselector position, said valve control being connected to said sensor when said selector meansv is in said first position so that .saidvalve will be actuated from the closed position to the 4open position when said sensor indicates the spray gun means to be in aspraying position, said valve means being held contiuuously in said open position by the valve control when saidV selector meansis in said second position.

5. An apparatus, as defined in claim 1, whereinsaid control means-includes timer means for actuating said drive means to move said spray lgun means from an advanced spraying position to said retracted positionat the end of a predetermined time.

- 6. An apparatus, as defined in claim 1, wherein said release agent portion of the manifold means comprises a block-,like .member having a passageway therein with a plurality of outlet ports, said air portion ofthe manifold means comprises a rigid tube structure secured to said block member and having. an internal passageway with a plurality of Aoutlet ports, said spray gun means comprises a pluralityof separate spray guns, saidZ apparatus including fitting means rigidly and adjustably mounting said spray guns of said air manifold tube structure and respectively connecting spray guns to the outlet ports of the air passageways, and a plurality of conduits respectively connecting spray guns to the outlet ports of said release agent passageway.

7. An apparatus, as defined in claim 6, wherein sai-d block member traverses and is secu-red to ends of said elongated rod-like members and said cam support member.

8. An apparatus, as defined in claim 1, wherein said frame comprises la -frame member disposed transversely with respect to said elongated rod-like members and extending outwardly in opposite directions therefrom, and attachment means on opposite end portions of said frame member for secu-ring said frame to tie-rods of a die-casting machine.

9. An apparatus for spraying material such as a release agent onto workpieces such as dies in a die-casting machine comprising a frame mountable adjacent a diedcasting machine, an elongated air cylinder mounted on said frame, an elongated piston rod telescopically associated With and operable by said cylinder and having an outer end piroL jecting laterally of said frame, 4a guide rod reciprocably mounted on said frame in parallel spaced relationship with respect to said piston rod, a manifold block connectedto and carried by outer ends of said rods yand having intern-al passageway means including an inlet port connectable with a source of release agent and a plurality of outlet ports, a rigid tube manifold structure secured to and carried by said block and having an internal passageway with an inlet port connectable with a source of air under pres'- sure and a plurality of outlet ports, a plurality of spray guns each having a release agent inlet port and an air inlet port, a plurality of pipe fitting means rigidly and adjustably mounting said spray guns on said tube manifold structure and connecting the outlet air ports of said manifold structure with the inlet air fports of the spray guns, and a plurality of flexible conduits respectively connecting the outlet ports of said block manifold member lwith the release agent inlet ports of the spray guns.

10.- An apparatus, as defined in claim 9, which includes an elongated cam support member parallel to said rods and connected with said block member, said support member having a longitudinally extending slot therein, cam means adjusta-bly mounted in said slot on said support member, and control means mounted on said frame for controlling the flow of the release agent and air to said spray guns, said control means including a sensor en-gageable with said cam means.

11. An apparatus, as defined in claim 10, wherein sai-d cam support member and said cam means are disposed over said rods and substantially over said frame in an exposed position for facilitating adjustment of the cam means.

References Cited UNITED STATES PATENTS 2,672,844 3/l954 Flint 118--315 2,878,058 3/ 1959 Gauthier et al. 1118-323 X 3,027,095 3/ 1962 Paasche 118-323 X 3,050,416 8/1962 Yahnke et al 118-315 X 3,266,729 8/1966 Baskett 239--186 CHARLES A. WILLMUTH, Primary Examiner.

J. P. MCINTOSH, Assistant Examiner.