Patent Publication Number: US-3878814-A

Title: Coating machine

Description:
United States Patent Brastow Apr. 22, 1975 [54] COATING MACHINE 3.653.356 4/1972 Brastow ll8/26l x [75] Inventor: Carl H. Brastow. Foxborough Mass Primary Examiner-Dorsey Newton [73] Assigneez lmemafional Shoe Machine Anurne v Agent. or F1rmAlbert Gordon Corporation. Nashua. NH.  
 [22] Filed: June 8, 1973 [57] ABSTRACT [2]] Appl&#39; 368437 A machine that applies coating material, by means of an applicator roll and a scraper blade, to a portion of [S2] U.S. Cl. 8/203; ll8/238; ll8/24l; the amp of 1! shoe upper that is mounted on a carlt8/261; 118/503 riage while the carriage is moving forwardly past the {5 l Int. Cl. B05 [/02 applicator roll and the scraper blade to thereby form a [58] Field of Search l l8/l04, 202 26! 238 box toe and that removes any blob of coating material 118/247, 241, 503 203 that had previously been formed on the scraper blade onto said portion of the vamp while the carriage is [56] Reference Cited moving rearwardly past the scraper bladei UNITED STATES PATENTS 9 Cl 23 D F&#34; 3,277 867 10/1966 Kilham ct 111. 1. 118/261 x rawmg in i l k mQ 46 I04 40 sf PATENTEUAPRZZIHIS SHEET 01 [1F 13 PATENTEU 3,878,814  
 SHEET UZOF 13 SHEET PIJENTEBAPRZZEYS 3 7 14 SHEEI 120F 13 l I I\\ \\W FIG. 17  
 FIG. 22  
 aa&#39;aa-aga sm i COATING MACHINE BACKGROUND OF THE INVENTION In my U.S. Pat. No. 3,653,356 and in my pending applications Ser. Nos. 185,022 filed Sept. 30, I971, which has been granted as U.S. Pat. No. 3,759,219. and 305,390 filed Nov. l0, l972, which has been granted as U.S. Pat. No. 3,807,354 there are disclosed machines for applying a coating to a portion of a workpiece wherein the workpiece is so supported on a block that the workpiece to be coated lies on top of the block. The workpiece is so held on the block that a part of the portion of the workpiece that adjoins the periphery of the workpiece portion to be coated extends downwardly of the block periphery. In these machines, the coating is applied to the desired portion of the workpiece by a rotating applicator roll that has a film of coating material of a prescribed thickness adhering to its periphery. The film is transferred from the applicator roll onto the desired workpiece portion while the applicator roll is so rotating about a prone axis that its bottom moves rearwardly and while a carriage, on which the block is mounted, is moving forwardly. The thickness of the coating transferred onto the workpiece is determined by a rearwardly facing scraping edge of a scraper blade that is located, heightwise, between the upwardly facing surface of the workpiece portion to be coated and the applicator roll bottom.  
  In the operation of the aforementioned machines. a residue of the coating material tends to adhere to and form a blob on the scraper blade at the end of the machine cycle. If this blob is not wiped off before the commencement of the coating operation during the forward carriage motion in the next machine cycle. the blob can transfer onto a part of the workpiece that it is not desired to coat. In order to solve this problem, the aforementioned machines include an arrangement wherein, during the rearward movement of the carriage at the beginning ofa machine cycle, the workpiece portion to be coated is wiped against the scraper blade to thereby wipe the blob onto the workpiece portion to be coated. While this arrangement is effective in wiping the blob off the scraper blade. it has been found to cause an undesired accumulation of the coating material to be forced upwardly between the scraper blade and the rotating applicator roll during the rearward movement of the carriage which is then transferred onto the workpiece during the forward movement of the carriage as to apply an excess quantity of coating material onto the workpiece that overflows beyond the periphery of the workpiece portion that it is desired to coat to thereby form an undesired ridge on the periphery of the coated workpiece portion.  
 SUMMARY OF THE INVENTION The problem ofthe undesired ridge, referred to in the preceding paragraph, is overcome by this invention. This is accomplished by so locating the block as it passes the scraping edge during the rearward carriage movement that the upwardly facing surface of the workpiece portion to be coated is spaced a greater dis tance from the applicator roll bottom than the thickness of the film of coating material adhering to the applicator roll and by so locating the scraper blade, during this rearward carriage movement, that the scraping edge bears against the upwardly facing surface of the workpiece portion to be coated.  
 BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an isometric view of the machine looking at the front of the machine;  
  FIG. 2 is a view similar to FIG. 1 which shows certain interior portions of the machine, not visible in FIG. I, in solid lines and shows other parts of the machine in phantom;  
  FIG. 3 is an isometric view of part of the machine looking at the back of the machine;  
 FIG. 4 is a front elevation of the carriage;  
 FIG. 5 is a view taken on the line 5-5 of FIG. 4&#39;,  
 FIG. 6 is a view taken on the line 6-6 of FIG. 4;  
  FIG. 7 is a plan view of a mechanism, in the machine, for applying the coating material;  
 FIG. 8 is a view taken on the line 88 of FIG. 7;  
 FIG. 9 is a view taken on the line 9-9 of FIG. 8;  
 FIG. 10 is a view taken on the line l0l0 of FIG. 8;  
  FIG. 11 is a side elevation of a cam follower mount and cam followers mounted thereto that are incorporated in the machine;  
 FIG. 12 is a view taken on the line l2l2 of FIG. I I;  
 FIG. 13 is a view taken on the line l3-I3 of FIG. 11&#39;,  
 FIG. 14 is a view taken on the line I4-l4 of FIG. 2;  
  FIG. 15 is a schematic representative of the pneumatic control circuit of the machine;  
  FIG. 16 is a representation of the cam followers and cams with which they cooperate at the beginning of the machine cycle.  
  FIG. 17 is a representation of the workpiece in the machine at the beginning of the machine cycle;  
  FIG. 18 is a representation of the workpiece in the machine during the rearward carriage movement while the blob of coating material is being wiped from the scraper blade onto the workpiece;  
  FIG. 19 is a representation of the cam followers and the cams at the completion of the rearward movement of the carriage;  
  FIG. 20 is a representation of the cam followers and the cams as the carriage commences its forward movement;  
  FIG. 21 is a representation of the workpiece in the machine during the forward carriage movement while the coating material is being applied to the workpiece;  
  FIG. 22 is a plan view of the workpiece with the coating applied thereto; and  
 FIG. 23 is a view taken on the line 2323 of FIG. 22.  
 DESCRIPTION OF THE PREFERRED EMBODIMENT The operator is intended to stand to the left of the machine as seen in FIG. I. The parts and positions closest to the operator will be designated front&#34; and the parts and positions furthermost from the operator will be designated back.&#34; Movements toward the operator will be designated as forward&#34; and movements away from the operator will be designated as rearward.  
  Referring to FIGS. 1-6, the machine comprises a mount 10 in which a carriage I2 is mounted for forward-rearward movement. An air-operated motor 14 is mounted to the back of the carriage 12. The motor 14 comprises a cylinder 16 rigidly mounted to the carriage l2 and a vertically movable piston rod 18 extending through the cylinder so as to project above the top of the cylinder and below the bottom of the cylinder. A collar 20 is mounted to the bottom of the piston rod 18. A bellcrank lever 22 is pivotally mounted, by means of a pivot pin 24, to the back of the carriage 12. An arm 26 of the lever 22 extends forwardly of the pivot pin 24 and is adapted to be interposed between the collar 20 and the bottom of the cylinder I6. Another arm 28 of the lever 22 extends laterally of the pivot pin 24 rearwardly of the back of the carriage 12. A bolt 30 is secured to and extends rearwardly of the back of the carriage l2 and has a nut 32 threaded thereon. The bolt 30 extends through the end 33 of the arm 28 remote from the pin 24 and the arm end 33 is yieldably urged rearwardly about the pin 24 against the nut 32 by a compression spring 34 that is entwined about the bolt 30 and is interposed between the back of the carriage I2 and the arm end 33. The spring 34 also acts to yieldably urge the arm 26 toward the piston rod 18.  
  A base 36 is rigidly mounted to the carriage above the cylinder 16. The base has a clearance hole 28 (FIG. 4) extending therethrough through which the top of the piston rod 18 extends. A plate 40 is secured to the top of the piston rod 18 by a screw 42 (see FIG. so as to be moveable heightwise in unison with this piston rod. The plate 40 extends between a pair of lateral flanges 44 on the carriage 12. A block 46, whose sides are rearwardly convergent. is secured to the top of the plate 40 thus forming a step 48 (see FIG. I7) in the sides of the plate 40 adjacent the peripheries of the sides of the block 46. A clamp 50 is secured in holders 52 that are mounted to the flanges 44. The sides of the clamp 50, which are located outwardly of the block 46 and converge rearwardly similarly to the sides of the block 46, are located above the step 48 outwardly of the sides of the block 46 (see FIG. 17).  
  An air operated motor 54, mounted to a bracket 56 that is secured to and extends upwardly of the mount 10, has a piston rod 58 that is secured to the carriage 12 so as to effect forward-rearward movement of the carriage.  
  Referring to FIG. 1, a cement melting chamber 60, which is shown in greater detail in the aforementioned applications Ser. No. 185.022 and 305,390. is fixedly mounted to the mount so as to extend above the carriage t2 and the members mounted to the carriage for forward-rearward movement therewith. A channel in the chamber 60 is in communication with a channel 62 (FIG. 10 as shown in said applications Ser. Nos. 185,022 and 305,390. The channel 62 is located between channel walls 64 and 66 that are fixedly secured to the mount I0 and the channel 62 extends from the channel 60 to a position above an applicator roll 68 and between a front wall 70 and a back wall 72. The applicator roll 68 and the front and back walls 70 and 72 are located between fixed side frame members 74. The applicator roll 68 is mounted in the side members 74 and is connected via a sprocket 76 (FIG. 8). a chain 78, (FIGS. 1 and 3) and a sprocket 80 (FIG. 3) to an electric motor 82 that is adapted to rotate the roll counterclockwise as seen in FIG. 10 so that its bottom moves rearwardly.  
  Flexible seals 84 and 86 (FIG. 10), made ofa heat resistant material such as silicon, respectively extend between the front wall 70 and the channel wall 64 and the back wall 72 and the channel wall 66.  
  In the manner shown in the aforementioned patent application Ser. Nos. 185.022 and 305,390, when the machine is running and the applicator roll 68 is rotating, the walls 70 and 72 are located in the FIG. l0 posi tion wherein they are spaced from the periphery of the applicator roll 68.  
  A scaper blade 88 (FIG. 10), having a rearwardly and downwardly extending bottom, is located below the front wall and forwardly of the applicator roll 68. The back of the scraper blade 88 extends circumferentially about and spacedly from the applicator roll 68 and terminates in a rearwardly facing scraping edge 90 that is located below the applicator roll. The blade 88 is mounted at its opposite ends to a pair of longitudinal bars 92 and 94 (FIG. 7). A transverse bar 96 is secured to and connects the bars 92 and 94. The bars 92 and 94 are pivoted to the side members 74 by pins 98 (FIGS. 7 and 10). A bracket 100 (FIG. I) is secured to and extends outwardly of the bar 92 and a bracket 102 is secured to and extends outwardly of the bar 94. Tension springs 104 secured to and extending between the brackets I00 and 102 and the mount 10 act to yieldably urge the bars 92 and 94 and the scraper blade 88 downwardly about the axis of the pins 98.  
  As shown in FIG. I, an inner cam 106 and an outer cam 108 are mounted to the carriage I2 so as to extend in forward-rearward directions alongside a side of the carriage. A cam follower mount 110 is affixed to the bar 94 and is located above the cams I06 and 108. Referring to FIGS. 11-13, an upper outer cam follower roll 112 is rotatably mounted to the mount 110, by means of a pin 113, so as to be in vertical registry with the outer cam 108. An inner cam follower roll H4, in vertical registry with the inner cam 106, is located at a lower level than the roll 112. The roll 114 is mounted to a holder 116 that is pivoted to the mount H0 by means of the pin 113. A spring I18 coiled about the pin I13 acts to yieldably urge the roll I14 rearwardly to a position wherein a pair of lugs 120 on the holder I16 abut a bar 122 on the mount 110. A lower outer cam follower roll 124, in vertical registry with the outer cam 108, is mounted forwardly of the cam follower rolls 1 I2 and 114. The roll 124 is mounted in a holder I26 that is pivoted to the mount I10 by means of a pin 128. A spring coiled about the pin I20 acts to yieldably urge the roll 124 rearwardly to a lower level than the cam follower roll 112. When the spring 118 urges the holder I16 to a rearward position wherein the holder I16 abuts the bar 122, the spring 130 urges the holder 126 to a rearward position, as shown in FIG. 11, wherein a lug 132 on the holder I16 abuts a latch 134 on the holder 126 to thereby preclude forward move ment of the holder II6 together with the cam follower roll 114. Referring to FIGS. 2, 3, and 14, a bellcrank level 136 is pivotally mounted by a pin 137 to a holder 138 that is affixed to the mount 10 rearwardly of the carriage 12. The bellcrank lever 136 has an arm 140 that extends downwardly of the pin 137 and an arm 142 that extends forwardly of the pin 137. A compression spring 143 interposed between a ceiling 144 of the holder 138 and a finger 145 on the lever 136 that ex tends rearwardly of the pin I37 urges the arm 140 forwardly and the arm 142 upwardly about the axis of the pin 137 to a position wherein the arm I42 engages the ceiling 144 and wherein a button 146 on the bottom of the arm 140 is in horizontal registry with a lug 148 on the back of the carriage 12, as seen in FIGS. 2 and 3. The bar 92 has a rearwardly projecting tail 150 that is below and in vertical registry with the lever arm 142.  
  When the machine is running in its idle condition: the piston rod 18 of the motor 14 is forced into its lowermost position in the cylinder 16 so that the step 48 is spaced from the clamp 50, (see FIG. 17 l; the spring 34 is yieldably urging the arm 26 against the piston rod 18 in a location that is between the collar 20 and the bottom of the cylinder 16 and is spaced from the collar 20; the piston rod 58 is projected out of the motor 54 so that the carriage 12 is in a forward position; the motor 82 is rotating the applicator roll 68 counterclockwise (FIG. and the walls 70 and 72 are spaced from the periphery of the applicator roll 68. In the idle condition of the machine, the springs 104 are yieldably urging the scraper blade 88 downwardly about the axis of the pins 98 to an idle scraper blade position determined by the engagement of the outer cam follower roll 112 with the rear of the outer cam 108 (see FIG. 16). At this time, the lug 132 is disengaged from the latch 134 so that the spring 118 urges the inner cam follower roll 114 downwardly against the back of the inner cam 106 and the spring 130 urges the outer cam follower roll 124 downwardly against the outer cam 108 (see FIG. 16). Molten thermoplastic coating material, which is melted in the melting chamber 60, flows through the channel 62 onto the rotating applicator roll 68 and adheres to the rotating roll so as to form a film on the periphery of the roll.  
  Referring to the schematic diagram of the pneumatic control circuit of the machine shown in FIG. 15, pressurized air is forced at all times, at a relatively low pressure, to the bottom of the cylinder 16 of the motor 14 so as to cause the motor 14 to yieldably urge the piston rod 18 upwardly under this relatively low pressure from a source 154 through lines 156, 158 and 160, a low pressure regulator 162, a line 164, a shuttle valve 166 and a line 168 to the bottom of the cylinder 16. The motor 14 is maintained in its idle position by pressun ized air under relatively high pressure passing through a high pressure regulator 169 in the line 156, the line 158, a line 170, a valve 172 and a line 174 to the top of the cylinder 16 so that the relatively high pressure in the line 174 overcomes the relatively low pressure in the line 168 to thus force the piston rod 18 downwardly to its lowermost position. The motor 54 is maintained in its idle position by pressurized air passing from the line 158 through a line 175, a valve 176 and a line 178 to the blind end of the motor 54.  
  Referring to FIG. 17, the vamp 180 of a shoe upper is placed on the block 46 in such a manner that its convergent sides are draped on the step 48 below and spaced from the clamp 50.  
  A manually actuated valve 182 is now momentarily shifted by the operator to permit pressurized air to flow from the line 156 through a line 184, the valve 182 and a line 186 to a pulse valve 188 to enable the pulse valve 188 to transmit a pulse of air from the pulse valve 188 through a pilot line 190. Pressurized air passes from the pilot line 190 through a pilot line 192 to the left side of the valve 172 to thereby shift the valve 172. The shifting of the valve 172 cuts off the flow of high pressure air to the top of the cylinder 16 ofthe motor 14 through the line 174 so that the low pressure air flowing into the bottom of the cylinder 16 through the line 168 can now raise the piston rod 18, together with plate 40 and the block 46, to a median position determined by the en gagement of the collar with the arm 26. In this position, the step 48, as shown in FIG. 18, is still spaced from the clamp 50 but the vamp 180 is held under relatively light clamping pressure between the clamp 50 and the block 46 with an exposed portion 194 of the vamp 180 located slightly higher than the top of the clamp 50.  
  After the shifting of the valve 172 and the raising of the piston rod 18, a flow control valve 196 in a pilot line 198 enables pressured air to flow from the line 190 through the line 189 to he left side of the valve 176 to shift this valve to thereby vent the pressurized air in the line 178 through the valve 176 and enable pressurized air to flow from the valve 176 through a line 200 to the rod end of the motor 54 to thereby cause this motor to move the carriage 12, together with the lightly clamped vamp 180, rearwardly. The outer cam 108, as shown in FIG. 16, has a rear upper segment 204 and a front lower segment 206 that are separated by an incline by an incline 208 that extends forwardly and downwardly from the upper segment 204 to the lower segment 206. As the carriage 12 moves rearwardly, the incline 208 moves past the cam follower roll 122 so that the springs 104 moves the mount 110, together with the scraper blade 88, further downwardly about the axis of the pins 98 to a level determined by the bearing of the cam follower roll 112 with the lower cam segment 206. This causes the scraping edge of the scraper blade 88 to be lowered downwardly about the periphery of the applicator roll 68 so as to bear against the exposed portion 194 of the vamp 180, as shown in FIG. 18, to pro vide the advantages described below.  
  Near the end of the rearward movement of the car riage 12 and when the cam follower roll 112 is approaching the front end of the lower cam segment 206. the lug 148 in the carriage 12 engages the button 146 to so swing the lever 136 about the axis of the pin 13&#39;! as to lower the lever arm 142 to thereby lower the tail 150 of the bar 92 and thus swing the scraper blade 88 and the mount upwardly about the axis of the pins 98. This rise of the mount 110 raises the cam follower roll 112 upwardly away from the lower cam segment 206, raises the cam follower roll 124 upwardly away from the outer cam 204 and raises the cam follower roll 114 upwardly away from the inner cam 106 to enable the springs 118 and 130 to respectively move the cam follower rolls 114 and 124 rearwardly until the cam follower roll 114 is locked against forward movement by the lug 132 and the latch 134 and is locked against rearward, movement by the abutment of the lugs against the bar 122 (FIG. 11). At this time, the cam follower roll 114 is substantially in vertical registry with and above the front of the inner cam 106 as indicated in FIG. 19.  
  Referring to FIGS. 2 and 3, a bumper 210 is mounted to the bracket 56 rearwardly of and in horizontal registry with the end 33 of the arm 28. As shown in FIGv 2, a spring return valve 212 is mounted to the mount 10 and is so related to a lug 214 depending from the arm 26 that the valve 212 and the lug 214 are in lateral horizontal registry when the carriage 12 has been moved by the motor 54 to its rearmost position.  
  Near the end of the rearward movement of the carriage 12 the bumper 210 engages the arm end 33 to move the arm 28 of the lever 22 forwardly with respect to the carriage 12 about the axis of the pivot pin 24 and to move the arm 26 of the lever 22 laterally away from the piston rod 18 in such a manner as to cause the lug 214 to engage and shift the valve 212 from its normally closed position to an open position. The lateral movement of the lever arm 26 causes it to be disengaged from and move out of vertical registry with the collar 20 to thereby enable the motor 14 to raise the piston rod 18, together with the plate 40 and the block 46, upwardly of the median position referred to above. The opening of the valve 212 enables pressurized air to pass from the line 158 through a line 2I6, the valve 212, a line 2I8 and a pilot line 220 to the right side of the valve 176 to shift the valve I76 to thereby vent the pressurized air in the line 200 through the valve 176 and enable pressurized air to flow through the line 178 to the blind end of the motor 54 so as to cause the motor 54 to move the carriage I2, together with the clamped vamp 180, forwardly. The opening of the valve 2I2 also enables pressurized air to flow from the line 218 through a pilot line 222 to the right side of a valve 224 to shift the valve 224. The shifting of the valve 224 enables pressurized air to flow from the line 158 under the relatively high pressure regulator I69 through a line 226, the valve 224, a line 228, the shuttle valve 166 and the line 168 to the bottom of the cylinder I6 of the motor 14.  
  From the foregoing it can be seen that. at the commencement of the forward movement of the carriage I2, at which time the exposed portion 194 of the vamp 180 is rearward of the bottom of the applicator roll 68 and the scraping edge 90, the piston rod 18 of the motor 14, together with the plate 40 and the block 46, is raised to an upper position, shown in FIG. 21, wherein the vamp I80 is tightly clamped between the step 48 and the clamp 50 and the exposed portion I94 of the vamp which is to be coated is situated above the clamp 50. The movement of the arm end 33 forwardly of the bumper 210, pursuant to the forward movement of the carriage 12, causes the spring 34 to again swing the lever arm 26 towards the piston rod I8 until the lever arm 26 abuts against the periphery of the collar 20. The movement of the lug I48 forwardly of the button I46, pursuant to the forward movement of the carriage l2, enables the springs 104 to lower the mount I10. together with the scraper blade 88, about the axis of the pins 98 until the cam follower roll II4 bears against the front of the inner cam 106, as shown in FIG. 20, to move the scraping edge 90 of the scraper blade 88 about the periphery of the applicator roll 68 to the position shown in FIG. 21, which is at a higher level than the FIG. 18 level of the scraping edge, wherein the scraping edge 90 is in contact with the exposed vamp portion I94.  
  The piston rod 18 is urged upwardly under the relatively low pressure of the air passing through the line I64 to place the block 46 in the median FIG. 18 position with the collar 20 bearing against the arm 26 so that there will not be such a frictional resistance to movement of the arm 26 away from the collar 20 as to inhibit such movement of the arm 26 at the end of the rearward movement of the carriage I2. The piston rod I8 is then urged upwardly under the relatively high pressure of the air passing through the line 228 to place the block 46 in the upper FIG. 2] position so as to rigidly clamp the vamp for the coating operation de&#39; scribed below.  
  The thickness of the film of thermoplastic coating material adhering to the periphery of the rotating applicator roll 68 is determined by the spacing between the front wall 70 (FIG. and the periphery of the roll 68. In the FIG. 21 position the heightwise distance between the top of the exposed vamp portion 194 and the lowermost portion of the periphery of the applicator roll 68 is less than the thickness of the film of coating material adhering to the roll so that coating material is trans ferred from the roll periphery onto the exposed vamp portion during the forward movement of the carriage 12 to form a coating 229 (FIGS. 22 and 23) on the vamp. The thickness of the coating of the thermoplastic material is determined by the spacing between the scraping edge and the vamp portion 194 with the scraping edge 90 scraping off that portion of the coating material that intersects it. The scraped off coating material is returned upwardly of the roll 68 into the chamber 62 by the rotating roll 68.  
  As shown in FIG. 20, the inner cam 106 has a rising portion 230 that rises in a rearward direction and a level portion 232. At the commencement of the forward movement of the carriage I2 the cam follower roll II4 bears against the cam portion 230 so that the scraping edge 90 is bearing against the exposed vamp portion 194. As the carriage 12 moves forwardly the cam follower roll 114 gradually rises to raise the scraping edge 90 about the axis of the pins 98 until the cam follower roll 114 levels off when it reaches the cam portion 232 to thus level off the elevation of the scraping edge 90. The coating 229, as indicated in FIG. 23, therefore is of graduated thickness at one end, as indicated by the number 234.  
  After the coating 229 has been applied to the exposed vamp portion 194 during the early part of the forward movement of the carriage 12, the cam follower roll I24 engages the incline 208 of the outer cam I08 which causes the cam follower roll 124 to swing forwardly against the force of the spring 130 to release the latch 134 from the lug I32 and thereby enable the cam follower roll 114 to swing forwardly against the force of the spring 118. As a result, the springs 104 during the remainder of the forward movement of the carriage 12 force the mount downwardly about the axis of the pins 98 until the cam follower roll 2 bears against the upper cam segment 204 of the outer cam 108 as in the idle condition of the machine.  
  Referring to FIGS. land 3, a cam 236 mounted to the carriage 12 is in intersecting relationship with a valve actuator 238 of a valve 240. The valve actuator 238 is so constructed. in a conventional manner, as to be moved by the cam 236 to momentarily open the valve 240 near the end of the forward movement of the carriage 12 and to not open the valve 240 when engaged by the cam 236 during the rearward movement of the carriage 12.  
  The momentary opening of the valve 240 near the end of the forward movement of the carriage 12 enables pressurized air to flow from the line 158 through a line 242, the valve 240 and a pilot line 244 to the right side of the valve I72 to shift the valve I72 to its idle condition. This shifting of the valve 172 enables pressurized air under the high pressure set by the pressure regulator I69 to again flow through the line 170, the valve 172 and the line 174 to the top of the motor 14. This shifting of the valve 172 also enables pressurized air to flow from the line 174 through a pilot line 246 to the left side of the valve 224 to shift the valve 224 to its idle position to thus cut off the flow of high pressure air to the bottom of the motor 14 by way of the line 228. The shifting of the valve I72 thus results in the lowering of the piston rod 18 to its idle position to lower the plate 40 and the clamp 50 to their idle FIG.  
 17 position so that the vamp 180 is released from the clamp 50.  
  The machine cycle is now completed and the vamp 180 with the coating 229 applied thereto may be removed from the machine. The coating 229 regidifies into a stiffener or box toe on the vamp 180 which. in a completed show, stiffens the toe portion of the shoe, The graduated portion 234 of the coating 229 forms the feathered edge which is desirable in box toes.  
  It has been found that at the end of a machine cycle a residue of coating material tends to adhere and form a blob on the scraping edge 90 and the portion of the scraper blade 88 contiguous thereto. If this blob is not wiped off before the commencement of the coating operation during the forward movement of the carriage 12 in the next machine cycle. the blob can be transferred onto the vamp portion 194 forwardly (leftwardly in F107 22) of the front of the coating to the left (FIG. 23) of the graduated portion 234. The placement of the scraper blade 88 and the exposed vamp portion 194 in the FIG 18 position during the latter part of the rearward movement of the carriage 12 causes the blob to be wiped off the scraper blade 88 by the vamp portion 194 during this rearward movement Since the blob thus wiped onto the vamp portion 194 forms a part of the coating 229 that is applied to the vamp portion 194 during the subsequent forward movement of the carriage 12, the wiping off of the blob onto the vamp portion 194 does not adversely affect the coating operation. In the FIG. 18 position, the exposed vamp portion I94 and the scraping edge 90 are spaced heightwise from the periphery of the applicator roll 68 a greater distance than the thickness of the film of coating material that adheres to the periphery of the applicator roll 68. Therefore no coating material is transferred from the applicator roll 68 onto the vamp portion 194 when the blob is wiped off the scraper blade 88 onto the opposed vamp portion during the rearward movement of the carriage 12. It has been found that if the vamp portion 194 and the scraper blade 88 are so located during the blob wiping operation as to transfer coating material from the applicator roll 68 onto the vamp portion 194, the transferred coating material tends to be forced upwardly into an accumulation between the scraper blade 88 and the rotating applicator roll 68 during the rearward movement of the carriage 12. This accumulation is then transferred onto the exposed vamp portion 194 during the forward movement of the carriage 12 when the coating 229 is applied to the vamp portion 194 in such an excess quantity that some of the coating material overflows downwardly beyond the periphery 248 (FIG. 21) of the exposed vamp portion 194 to thus form an undesired ridge on the periphery of the coating 229. This undesired ridge is alleviated, in accordance with this invention, by spacing the scraper edge 90 and the exposed vamp portion 194 during the blob wiping operation a greater distance from the periphery of the applicator roll 68 than the thickness of the film of coating material on the periphery of the applicator roll 68 so that no coating material is transferred from the applicator roll 68 onto the exposed vamp portion 194 during the blob wiping operation.  
 I claim:  
  1. A machine for applying a coating to a portion of a workpiece comprising: an applicator roll mounted for rotation about a prone axis; means for so rotating the applicator roll about said axis that the bottom of the applicator roll moves rearwardly; means for so dispensing coating material to the applicator roll as to cause a film of the coating material of a prescribed thickness to adhere to the roll periphery; a scraper blade located adjacent to and spacedly from the applicator roll having a rearwardly and downwardly extending bottom that terminates in a rearwardly facing scraping edge; means mounting the scraper blade for heightwise movement; a carriage. located below the applicator roll and the scraper blade, mounted for forward-rearward movement; a workpiece supporting block, mounted to the carriage for heightwise movement, so constituted as to support the workpiece with said workpiece portion lying on top of the block and at least a portion of the workpiece adjoining the periphery of said workpiece portion extending downwardly of the block periphery; means for initially maintaining the carriage in a front position wherein the workpiece may be placed on the block in a location that is forward of the applicator roll and the scraping edge; means for moving the carriage rearwardly from said front position to a back position wherein said workpiece portion is rearward of the scraping edge and the applicator roll bottom; means, effective when at least a part of said workpiece portion is moving rearwardly past the scraping edge, to place the block in a lower block position wherein the block top is so spaced from the applicator roll bottom that the upwardly facing surface of said workpiece portion is a greater heightwise distance from the applicator roll bottom than the thickness of the film; means, effective when the block is in said lower block position. to place the scraper blade in a lower scraper blade position wherein the scraping edge bears against said upwardly facing surface; means for thereafter moving the carriage forwardly from said back position to said front position; means, effective during the forward movement of said workpiece portion past the applicator roll bottom and the scraping edge, to place the block in an upper block position wherein the block top is so spaced from the applicator roll bottom that said upwardly facing surface is a lesser heightwise distance from the applicator roll bottom than the thickness of said film; and means, effective during the forward movement of said workpiece portion past the applicator roll bottom and the scraping edge to place the scraper blade in an upper scraper blade position wherein said scraping edge is located heightwise between said upwardly facing surface and the applicator roll bottom; whereby, during said forward carriage movement, the applicator roll transfers coating material to said workpiece portion of a thickness determined by the heightwise spacing between said scraping edge and said upwardly facing surface; and whereby, during said rearward carriage movement, any blob of coating material that had previously been formed on the scraper blade is wiped onto said workpiece portion.  
  2. The machine according to claim 1 wherein said means to place the scraper blade in said lower scraper blade position and said means to place the scraper blade in said upper scraper blade position comprises: forwardly-rearwardly extending cam means mounted to said carriage; a cam follower mount connected to the scraper blade for heightwise movement therewith; cam follower means, mounted to the cam follower mount, located above and in heightwise registry with the cam means; means for yieldably urging the cam follower mount, together with the scraper blade, downwardly to thereby yieldably urge the cam follower means against the cam means; and means so constructing and arranging the cam means and the cam follower means as to cause the cam follower mount to be in a lower cam follower mount position. to thereby place the scraper blade in said lower scraper blade position, during at least that part of said rearward carriage movement wherein said part of said workpiece portion is moving rearwardly past the scraping edge and to cause the cam follower mount to be in an upper cam follower mount position, to thereby place the scraper blade in said upper blade position, during at least that part of said forward carriage movement wherein said workpiece portion is moving forwardly past the applicator roll bottom and the scraping edge,  
  3. The machine according to claim 2 wherein said cam follower means comprises: a first cam follower fixedly mounted to said cam follower mount; a second cam follower so movably mounted to said cam follower mount that it may be in a locked condition wherein it is locked against movement on the cam follower mount or in an unlocked condition wherein it is free to move upwardly of a locked position wherein it is in said locked condition; and further comprising: means enabling said second cam follower to be in said unlocked condition during said part of said rearward carriage movement wherein said part of said workpiece portion is moving rearwardly past the scraping edge to thereby enable said first cam follower to bear against the cam means so as to cause the cam follower mount to be in said lower cam follower mount position; and means enabling said second cam follower to be in said locked condition during said part of said forward carriage movement wherein said workpiece portion is moving forwardly past the applicator roll bottom and the scraping edge to thereby enable said second cam follower to bear against the cam means so as to cause the cam follower mount to be in said upper cam follower mount position.  
  4. The machine according to claim 3 further compris ing: means so constructing the cam follower means as to move said second cam follower into said locked condition in response to movement of the cam follower means upwardly of the cam means; means so constructing the cam means and the cam follower means as to enable said second cam follower to be released from said locked condition into said unlocked condition dur ing said forward carriage movement after said workpiece portion has moved forwardly past the applicator roll bottom and the scraping edge, means, effective during said rearward carriage movement when said part of said workpiece portion has moved rearwardly past the scraping edge, to so raise the cam follower mount as to raise the cam follower means upwardly of the cam means so as to enable said second cam follower to move into said locked condition; and means, effective pursuant to said forward carriage movement, to enable the cam follower mount to descend to thereby lower said second cam follower, in locked condition, against the cam means.  
  5. The machine according to claim 4 further comprising: a frame member; a rearwardly extending tail so movably mounted to the frame member and so rigidly connected to the scraper blade and to the cam follower mount as to cause the scraper blade and the cam follower mount to move downwardly in response to upward movement of the tail and to cause the scraper blade and the cam follower mount to move upwardly in response to downward movement of the tail to thereby provide said heightwise mounting of the scraper blade and the cam follower mount; a holder located rearwardly of the carriage; a lever, pivoted to the holder, having a forwardly extending arm that is located above and in intersecting relation with the tail and a downwardly extending arm that is located rearwardly of and in intersecting relation with the back of the carriage; and means for applying a yieldable force to the lever so as to urge the forwardly extending lever arm upwardly and the downwardly extending lever arm forwardly; whereby the engagement of the back of the carriage with the downwardly extending lever arm overcomes said yieldable force to thereby cause the forwardly extending lever arm to move downwardly and engage the tail to move the tail downwardly and thus serve as said means, effective during said rearward carriage movement, to raise the cam follower mount; and whereby the movement of the carriage forwardly of the downwardly extending lever arm enables the yieldable force to raise the forwardly extending lever arm upwardly of the tail and thus serve as said means, effective pursuant to said forward carriage movement, to enable the cam follower mount to descend.  
  6. The machine according to claim 1 further eomprising: a rod, mounted in the carriage for heightwise movement, located below and connected to the block to thereby provide said mounting of the block to the carriage for heightwise movement; a motor operatively connected to the rod to impart heightwise movement to the rod and the block: a collar mounted to the rod below and spacedly from the block; an arm mounted to the carriage for movement toward and away from the rod; means, effective during the rearward carriage movement when said part of the workpiece portion is moving rearwardly past the scraping edge, to cause the motor to force the rod to a lower rod position wherein the top of the collar abuts the bottom of the arm to thereby place the block in said lower block position; and means, effective during the forward carriage movement when said workpiece portion is moving past the applicator roll bottom and the scraping edge, to move the arm outwardly of the collar and to cause the motor to move the rod, together with the block, upwardly of said lower rod position to an upper rod position to thereby place the block in said upper block position.  
  7. The machine according to claim 6 wherein said arm is a forwardly extending lever arm that forms part of a lever mounted by a pivot to said carriage and extends forwardly of said pivot; and further comprising: a laterally extending arm of said lever extending laterally of the pivot and rearwardly of the carriage; spring means interposed between the lever and the carriage effective to yieldably urge the laterally extending arm rearwardly and the forwardly extending arm inwardly towards the rod; and a stationarily mounted bumper so located rearwardly of and in registry with the laterally extending arm as to swing the laterally extending arm forwardly about said pivot in response to engagement with the laterally extending arm at the end of the rearward carriage movement to thereby swing the forwardly extending arm outwardly of the collar.  
  8. The machine according to claim 7 further comprising: an actuator so located and constituted as to be intersected and actuated by said forwardly extending arm during said outward swinging of the forwardly extend-