|Publication number||US2105572 A|
|Publication date||Jan 18, 1938|
|Filing date||Sep 5, 1935|
|Priority date||Sep 5, 1935|
|Publication number||US 2105572 A, US 2105572A, US-A-2105572, US2105572 A, US2105572A|
|Inventors||Williams Wilbert S|
|Original Assignee||Solar Lab|
|Export Citation||BiBTeX, EndNote, RefMan|
|Referenced by (9), Classifications (4)|
|External Links: USPTO, USPTO Assignment, Espacenet|
m 1938- w. s. WILLIAMS ,3
STENC ILING APPARATUS Filed Sept. 5, 1935 9 Sheets-sheaf, 1
IN VEN TOR. 1mm 5. "47/6/75.
. I ATTORNEYS.
Jan. 18, 1938.; w. s. WILLIAMS 5,
' STENQILING APPARATUS Filed Sept. 5, 1935 9 Sheets-Sheet 2 INVENTOR. Wl/berf 5. MY/wms. *m%
Jan:. 18, 1938. w. s. WILLIAMS STENCILING APPARATUS Filed Sept. 5, 1935 9 Sheets-Sheet 4 INVENTOR. Wflberf 5 MY/jams.
18, 1%38. wJs. WILLIAMS 2,105,572
' STENCILING APPARATUS Filed Sept. 5, 1935 9 Sheets-Sheet 5 f f f 4 INVENTOR.
Jan. 18, 1938. w. s. WILLIAMS STENCILINGAPPARATUS Filed Sept. 5. 1935 9 Sheets-Sheet 6 IN V EN TOR. W/Iberf .5 Wl/llms ATTORNEYS.
jan. 18,1938. w. s. WILLIAMS 2,105,572
STENC ILING APPARATUS Filed Sept. 5, 1935 9 Sheets-Sheet 7 I N V EN TOR. Wi/bzrf .5 Williams M v ATTORNEYS.
Jan. 18, 1938. w. s. WILLIAMS 7 STEl ICILING APPARATUS 9 Sheets-Sheet 8 I N V EN TQR. Wilber/fi Williams.
Filed Sept. 5, 1935 BY v v M r ATTORNEYS.
Jan. 18, 1938. w. s. WILLIAMS STENCILING APPARATUS Filed Sept. 5, 1935 9 Sheets-Sheet 9 INVENTOR.
ATTORNEY Patented Jail. is, 1938 UNITED STATES PATENT OFFICE STENCILING APPARATUS- Application September 1935, Serial No. 39,305
49 Claims. (Cl. 101-124) My invention relates to stenciling apparatus. It has to do, more particularly, with an apparatus to .be used in stenciling designs or configurations on articles by the process commonly known 5 as the screen-stencil process. More specifically, it relates to a machine for stenciling designs or other markings on glass articles and, especially, on glass articles having a frusto-conical or tapered surface, although it is not necessarily lim- 19 lted thereto.
There have been a number of machines devised in the past for stenciling designs on articles by 'the screen-stenciling process. Most of these machines have been hand-operated but,
lately, there have been attempts to design a satisfactory automatic machine. Most of these attempts have resulted in machines which are cumbersome,of a complicated structure and requiring U more than one operator to keepthem in opera- 20 'tion.
In the decoration of glassware, and particularly such articles as tapered tumblers and footed goblets, one problem that arises is the provision of an apparatus that may be readily and efiectively adapted to the decoration of articles having a very slight ta'per or articles having a substantial taper. In the prior art, some efforts have been made to provide adjustments which will make possible the ready changing of the machine for decorating either slightly tapered articles or articles which are quite substantially tapered. These efforts have contemplated, mainly, the use of stencil screens of fiat or plane form, with either the article or the screen swinging so as to cause the article to traverse an arcuate path in contact with the screen during the decorating operation. The point about which either the article or the screen swings is made adjustable to change the arc of the swinging movement to adapt the apparatus to printing on articles of different degrees of taper. Another prior art machine has employed a frusto-conical or tapered stencil of substantialy drum-like form. It has been difficult, however, to adjust these machines for decorating articles of different taper. Also, all of these machines have been diificult to load and unload. In most of these machines it is necessary to provide a conveyor for bringing the article into position beneath the screen stencil.
However, the use of such conveyors involves certain complications and disadvantages and increases both the cost of the machines themselves and the cost of operation. Also, usually more than one operator is required for operating such I machines. These-prior art machines. have also been possessed of a number of other disadvantages.
One of the objects of my invention is to provide a machine for stencillng designs or markings on articles by use of the screen process which is automatic in its operation but which is of very simple and compact structure and which can be constructed at a comparatively low cost. 7
Another object of my invention is to provide a machine of the type indicated which may be operated by a single operator but which will have a large capacity.
Another object of my invention is to provide a machine for stenciling designs or markings on tapered articles and which is so designed that there will be no slippage between the surface of the article and the surface of the stencil and, consequently, there will be no smearing ofthe design or marking applied to the article.
-Another object of my invention is to provide a machine of the type indicated which may be very easily and quickly loaded and unloaded by a single operator and wherein it is not necessary to provide conveyors or other complicated mechanism to position the articles beneath the screen stencil.
In its preferred form, my invention conteme plates the provision of a machine embodying a screen stencil which takes the form of a segment of a cone which is caused to travel about the axis of said cone in first one direction and then in the other direction with the article in printing contact therewith during each movement. The screen stencil is so constructed that it is a segment of a cone which has a taper which approximates the taper of the article being decorated but the stencil is preferably of greater diameter than the article. It is adjusted to such a position that the axis of the cone of which it forms a part will intersect the axis of the tapered article at the apex of the said cone and at the apex of the cone which would be formed by continuation of the sides of the tapered article. This results in the movement of the screen stencil and the article in rolling contact in such a manner thatthe contacting points of the screen and article throughout the length of the article will travel at the same rate of speed with the result that slippage and consequent smearing of the design is avoided.
Furthermore, the *segmental conical screen stencil which-I utilize is so mounted for movement that the articles may be fed to the machine'and removed from the side thereof which is at the side where the operator stands and the form of my machine.
. master valve.
operator can remove a decorated article 'with one hand and immediately place an undecorated article on the chuck with the other hand. In addition, mechanism is provided for moving the screen stencil automatically while the chuck which holds the article is 'so constructed and operated that the placing of the article thereon will automatically initiate movement of the screen'while, at the termination of each movement, the'article will be released automatically. The screen stencil is preferably made of cloth and the article is disposed within the arcuate or seg-. mental screen stencil so that if the cloth stencil shrinks and tends to approach the chord of its are it will merely result in better contact of the screen stencil and the article. i
The preferred embodiment of my invention is illustrated in the accompanying drawings wherein similar characters of reference designate corresponding parts and wherein:
Figure 1 is a'perspective view of a machine constructed in accordance with the principles of my invention. I
Figure 2 is a view mainly in side elevation but partly in section of the machine illustrated in Figure 1. I 1 Figure 3 is a plan view of the machine illustrated in Figures 1 and 2.
Figure' i is a more or less diagrammatic view of the fluid actuating mechanism and associated parts of the machine.
Figure 5 is a detail in section of the vacuum chuck for supporting the article and the operating mechanism therefor.
Figure -6 is 'a detail in section of the clutch mechanism which controls reciprocation of the screen stencil.
Figure 7 is a section taken substantially on line l-I of Figure 6.
Figure 8 is a perspective view of a. portion of the clutch mechanism illustrated in Figure 6.
Figure 9 is a front elevation of a portion of the machine illustrated in Figures 1, 2 and 3'.
Figure 10 is a detail in section of a safety device incorporated in the driving mechanism.
Figure 11 is a detail partly in section and in perspective 'of a portion of the arcuate member which supports the screen stencil.
Figure 12 is a detail in perspective of part of the means employed for controlling the squeegee.
Figure 13 is a perspective view of a modified Figure 14 is. a detail, partly in section and partly in side elevation, of the machine illustrated in Figure 13.
Figure 15 is a sectional view illustrating how'a poppet valve may be provided for operating the Figure 16 is a sectional view taken substantially on line l6-l6 of Figure 15. p
Figure 17 is a perspective view, partly broken away, of a unit mounted, at each end of the screen stencil for preventing the paint or printing material from accumulating at the ends of the-screen stencil.
Figure 18 is a sectional view showing the unit illustrated in Figure 17 in oneposition during operation.
Figure 19 is a view similar to Figure 18 showing the unit in another position during operation.
Figure 20 is a plan view illustrating how one of the units is positioned at each end of the screen stencil.
With reference to the drawings, and particularly to Figures 1, 2 and 3, I have illustrated my which carries an electric motor l2.
machine as comprising mainly an article supporting chuck l, screen and squeegee printing mechanism 2 disposed above the article, clutch mechanism 3 for controlling the reciprocation of the screen stencil transversely of the article .and'for rotating the article about its own axis, and'a double unit cylinder and piston mechanism 4 for controlling the clutch mechanism 3. All of these various units are carried by a supporting frame 5,
which is adjustably mounted on a supporting table 6. The frame 5 carries at its lower end a curved plate 1 which rests in a curved cradle 8. The plate 1 is secured in position in the cradle by means of bolts 9 which pass through slots I 0 formed in the plate. It will be apparent that the bolts and slots willpermit adjustment of the plate 'I to various positions in the cradle so that the main portion of the machine, that is all the units carried by the frame 5, may be adjusted to any desired position relative to the horizontal and secured in adjusted position.
The supporting table 6 has a rear extension II This motor drives a pulley I 3- through the intermediary of a worm and worm wheel unit M. The pulley l3 drives a pulley l5 which is disposed adjacent the forward edge of .the table by'means of a. belt H5. The pulley i5 is keyed on the outer end of a shaft l1. This-shaft I1 is made in two sections which are rotatably mounted in suitable bearings and it extends to a point within the clutch housing 18 of the clutch unit 3.
In order to avoid injury to the machine in case a part or parts thereof bind or become inoperative for any reason, I interpose a safety device I9 between the two sections of the 'shaft IT. This safety device is illustrated best in Figure 10. As
shown, one section 20 thereof is keyed to the end of one of the sections of the shaft I1. section 2| is keyed to the adjacent end of the other section of the shaft. The two sections are normally caused to rotate together by means of a plurality of balls 22 which are normally pressed into the sockets 23, carried by the section. 20, by means of springs 24 However, if for any reason the driven section of the shaft I! will not rotate, the balls 22 will be forced inwardly against the springs 24 and out of the sockets 23 in the section 20, permitting the section 20 and'the section 2| each other and, thus, preventing injury to the machine. The springs 24 are of sufficient strength to normally maintain the balls 22in the sockets 23. They are carried in socket members which are carried by a member 25 that is screwed on the section 2| and held in adjustable position thereon by a set screw 2 la. The member 25 may be adjusted on the section 21 to vary the force exerted by the springs and to keep the balls 22 seated in the sockets 23.
As previously stated, the shaft l1 extends within the housing l8 which contains the clutch mechanismadapted to control the reciprocating movements ofthe screen stencil and rotation of the article. As shown in Figures 2, 4 and 6, the inner end of this shaft I! has a bevel gear 26 keyed thereon. This gear 26 drives a bevel gear 21 in one direction and a second bevel gear 28 in an opposite direction. These gears Hand 28 are disposed within the clutch housing and form part of the clutch mechanism. They are loosely mounted for rotation on a hollow shaft 29 which extends through the clutch housing. The gears 21 and 28 are constantly driven by the gear 26 Another carried by the section 2|.
to rotate relative to normally rotate on the shaft 29. Each of the 76 I gears 21 and 28 has a chamber 30 formed therein .member 32 which is keyed to theshaft 29. This arm member has pivoted to each end thereof a shoe .33 as at 34. Each shoe 33 is made of an inner and outer section both of which are pivoted to the arm 32. The inner section 33a may be spaced apart from the outer section to any desirable extent by adjustment ofwedge bolt 35 which is disposed between the two parts. A spring 35 is provided for normallyurging each shoe 33 to swing inwardly towards shaft 29. This spring is connected at one end to the pivot 34 and at its opposite end to a member 31 which is pivoted to the outer section of the shoe and has an extension 38. This extension 38 contacts with a small pin 39 on the inner section 33a. It will in such a manner that the shaft may freely rotate jbe understood that the spring 36 not only tends to swing the entire shoe 33 inwardly but also tends tokeep the inner section 33a of the shoe in contact with the outer section thereof since the member 31 tends to swing around its pivot and by means of extension 38 and pin 39 to force the inner, section 33a against the outer section. However, as previously stated, the wedge bolt 35 limits the extent to which these two members are spaced apart.
As shown in Figure 6, the inner surface of each of the sections 33a of the shoes 33 is beveled as indicated at 40. A sleeve member 4| which has frusto-conical ends is mounted on the shaft 29 therein. 'Also the sleeve may be moved. longitudinally of the shaft. The frusto-conical ends of housing and is pivoted thereto.
the sleeve 4| are adapted to be moved into the frusto-conical sockets formed within the shoe members 33 by the tapered surface 40. However, both ends of the sleeve are normally out of the sockets so that the clutch will normally be in neutral, as illustrated in Figure 6. The shoe members 33 carry brake bands 42 that are adapted to frictionally engage the inner peripheral wall of the drum-like chambers 30. When the frusto-conical end of the sleeve 4| is moved between the two shoe members 33 of one of the units 3|, it spreads the shoes apart causing the bands 42 to engage the wall of the chamber 30 and, consequently, causes the bevel gear to rotate with the shaft 29. The sleeve 4| may be moved longitudinally of the shaft 29 to cause either of the bevel gears to be clutched thereto by means of a lever 43 that extends upwardly from the It will be apparent that when the bevel gear 21 is clutched to the shaft 29, the shaft will rotate in one direction and when the bevel gear 28 is clutched tov the shaft, the shaft 29 will rotate'in an opposite direction.
The shaft 29 extends forwardly to the front end of the machine. This shaft 29 is adapted to cause the screen stencil support to reciprocate .and also to rotate the article about its axis. The forward end of the shaft 29 carries the chuck l, as illustrated best in Figures 2, 4 and 5. This chuck comprises a collar 44 which is keyed to the shaft 29 adjacent its forward end. One end of a spring 45 abuts this collar 44 andjhe other end of the The.
spring abuts the spider-like structure 46 which is disposed forwardly of the collar 44 and is free to slide on the shaft 29. A second structure 4'! identical with that just described is disposed on the shaft at a point spaced a short distance rearwardly of the first structure. However, the arms of the spider-like member of this structure are longer than those of the other. The article is adapted to be placed on the chuck, as illustrated.
in Figures 2 and 5. It will be firmly supported thereon since the spider-like structures are free to move inwardly to compensate for variations in the taper of the articles.
As previously stated, the shaft 29 is hollow and has a passage way 48 extending from one end thereof to the other. This passageway is adapted to be connected to a vacuum pump. The forward end of the shaft 29 has a suction cup 49 which is preferably formed of rubber mounted thereon.
The edge of this suction cup 49 is adapted to engage the bottom of the article as illustrated in Figure 5. The suction cup is removably held in position by a collar 50 threaded into the forward end of the shaft 29. The shaft 29 has a rod mounted therein for longitudinal movement.
This rod is normally urged outwardly by a spring 52 disposed in a chamber 53 into which the rear end of the rod extends. This chamber 53 is formed in a valve housing 54 which is bolted or otherwise secured to the rear end of the frame 5. The spring 52 engages a collar 55 on the rod. The rear end of the spring is disposed in a socket formed in the forward end of a plunger 56 which is slidably mounted in the chamber 53. This plunger 56 has an annular groove 51 formed therein. When the rod is pushed inwardly as illustrated in Figure 5, the groove 5'1 is in alignment with an opening 58 formed in the housing 54 and to which a vacuum line 58a is connected. It is also in alignment with aduct 59 which leads forwardly through thehousing 54 and communicates with the passage 48 in the hollow shaft 29 by means of an opening 50. Thus when the rod 5| is in its innermost position, the passage 48 is in communication with the vacuum line connected to the opening 58 in the housing 54. The
plunger 55 may. however, be moved into a position where the groove 51 will align with openings 6| and 62 that will permit air from the atmosphere to enter through the passage 59, opening 60 and into the passage 46. The rod 5| extends forwardlyv through the collar 50 and projects from the shaft. It is loose in the collar 50 so that air may be exhausted from within the vacuum cup 49 by means of the vacuum line connected with the passage 48. The forward end of the rod has a sleeve member 5|a threaded thereon as at 5Ib so that the length of 'the rod may be varied. The extreme forward end of the rod has a button 5|c of rubber adapted to contact with the bottom of the article.
When the article is not in position on the chuck, the rod will extend forwardly a considerable distance past the outer edge of the cup 49 as illustrated in Figure 4., At this time, the plunger 56 will be in such a position that air from the atmosphere will be permitted to enter the passage 48. As soon as an article is positioned on the chuck, the bottom thereof will strike the forward end of the rod and will move it rearwardly. This will move the plunger rearwardly and cause communication to be established between the vacuum line and the pasasge 48. Consequently, the air will be exhausted from the passage 48 and the interior of the vacuum cup 49 and the article will the rod 5! to be forced forwardly in order to release the article from the chuck.
Behind the chuck I the shaft 29 has a gear 83 keyed thereon. This gear 63 meshes with an arcuate rack 54 as illustrated in Figures 2, 4 and 9. The rack 64 is carried on the rear surface of an arcuate screen stencil supporting member 85. This screen stencil supporting member is supported on the machine in such a manner that it may be reciprocated by the gear 63 which engages the rack 84. As shown best in Figures 2 and 3, the member 65 is mounted for reciprocation in a cradle formed by a plurality of rollers 88. These rollers engage the edges of the member 85. I preferably provide a. pair of rollers that engage the 'top edge of the member 65 and two pairs of rollers that engage the bottom edge thereof. In other words, the member 65 will be supported at three points as illustrated best in Figure 3. The rollers 88 are supported on arms 81 which are suitably secured to a. plate 68 that has arms with curved rear surfaces. These arms are adjustably supported in a cradle 89 by means of bolts and slots 10. The cradles 89 are formed in arms carried by a member II. This member H has a curved rear surface 12 which fits into cradles formed in the forward surfaces of arms on a member 13. The member 1| is adjustably held in the cradle in the member 13 by means of slots and bolts 14. The member 18 has arms on a vertically disposed extension 15 extending upwardly therefrom which has a projection on its rear 'surface that slides in a 'guideway formed in a. vertically disposed plate I8 that is mounted on the clutch housing l8. The member 15 is adjustably secured to the member 18 by bolt and slot connections 11. Thus, the member 15 maybe vertically adjusted on the member 18 to raise or lower the screen stencil supporting member 85. The member 68 may be adjusted in its cradles and the member 1| may be adjusted in its cradles to tilt the support The member 65 may be tilted to any desired angle. This adjustment is important for reasons which will appear here-- inafter. The outer edges of the gear teeth of the rack 8.4 are rounded as at 18 (Figure 1) so that the gear 63 will firmly mesh with the rack :4 rcgardless of the tilted position of the mem- The member 65 has a forwardly projecting arm 19 secured thereto adjacent each end thereof.
Each arm 19 has a lug formed 'on its rear end which has a curved rear surface that fits on a correspondingly curved surface formed on a lug member 8| as illustrated at 82. The member 80 is secured to the member 8| by means of bolt and slot .connection 83. Because of this connection, the member I9 may be adjusted to .any desired position relative to the horizontal and secured in adjusted position. The lug III is secured to the member by a bolt and slot connection 88 and the member 85 is provided with a plurality of bolt openings 85 spaced therealong so that the lug 8| may be moved to various positions. The forward ends of the arms 19 are tied together-by a curved member 88..
The arms I9 are adapted to support the screen stencil 81. As shown, this stencil comprises a screen which is preferably made of silk that is stretched and fastened to'a wooden frame 88.
This frame 88 has plates 89 secured thereto at both ends and they project outwardly therefrom. These plates are adapted to be received between four lugs 98 formed on each of the arms [9. The two top lugs 98 have screw bolts 9| threaded downwardly therethrough and the two bottom lugs have screw bolts 9| threaded upwardly therethrough. Thus the plates 89 may be clamped between the bolts SI and these bolts may be adjusted to obtain slight vertical adjustment of the screen stencil relative to the arms 19.
As previously stated, the screen 8.1 is preferably in the form of a segment of a cone. This is important when it is desired to decorate tapered articles. The taper of the screen stencil should be approximately the same as the taper of the article in order to avoid slippage between the surface of the screen stencil and that of the article but the screen stencil is preferably of greater diameter than the article. However,
"in order.to avoid slippage, it is also necessary article.
I If the taper of the articles being decorated by the machine variesconsiderably from time to time, the screen stencil'should be replaced with a screen stencil having substantially the same taper as the articles to be decorated. Also, the
member 65 should be adjusted to a different tilted position so that the segmental screen will move back and forth about its axis line which intersects the axis of the article, as described above, in order to avoid'slippage. The member .65 may be readily adjusted, as previously described, and the screen 16 may be readily removed and replaced by a different screen.
In order to force the paint or other printing material through the screen stencil, I provide the squeegee mechanism 2, as previously described. This squeegee mechanism comprises a forwardly extending arm 92 which has its rear end secured to a vertical member 93 that is slidably mounted for vertical movement on a member 94. This member 94 is secured to an L- shaped bifurcated structure 95 that is pivotally secured as at 98 to the member 88 which carries the member 65. The member 92 has a slot 91' formed therein which receives the upper end of a support 98 that has the squeegee member 99 secured to its lower end. The member 98 is pivotally secured to the arm 92 asat Hill by a pivot pin which may be disposed in any of a number of openings NH along the arm 92. The
squeegee 99 embodies two plates I02 which clamp through this slot. This rod I08 has its rear end mounted in the upper end of member 93. Dis- '-posed in surrounding relation to the rod I08 at opposite sides of the member I06 are springs I09. These springs oppose each other. The force which they exert may be varied by adjusting nuts IIO which are threaded on the rod. The springs will permit the squeegee to rock about the .pivot point I30 in case of variations in the articles. Also,'th'e springs may be adjusted so that one exerts more force than the other and thereby tend to rock the squeegee about the pivot point in one direction. This would cause one end of the blade I03 to press down on the screen stencil with more force than the other end thereof. This adjustment may be desirable if the screen is not exactly the same taper as the article for slightly distorting the screen stencil so that it will assume substantially the same taper as the article. I It will be apparent that the member 65 will be reciprocated, causing movement 'in first" one direction and then the other ofthe screen stencil relative to the article and also relative to the squeegee. This will cause the squeegee to Wipe over the surface of the screen stencil. During this movement, the outer end of the squeegee supporting arm 92 is supported by means of the structure I05 which carries a roller III on its lower end that is spaced above member 86. The member 88 ismade of an angle iron and has an upstanding flange H2. The roller III is mounted on the outer end of a shaft II3 which is slidably I mounted in a hearing I I4 -on the lower end of ssrij member I05. A bar 4a is pivoted to the upper end of member I05 as at 5. The lower end of this bar bears against the outer end of the roller shaft II3. A spring I I6 is provided which .tends to swing the bar I I4a inwardly. This tends m to push the roller shaft II3 inwardly.
It will be apparent that when the screen stencil is moved in one direction to the extent of its movement, the paint or printing material will v be scraped over the surface of the stencil and the greater portion thereof will be carried to one end of the stencil. When the screen is then moved in the opposite direction, the paint piled up by the stencil would not be carried alon towards the other end of the stencil unless some means were provided for causing the squeegee to get to the opposite side of the small pile of paint. In order to always keep paint in front of the squeegee, regardless of the direction of movement of the'screen stencil, I provide the struc- :.7 ture to be described now. This structure comprises a track member I I1 that is mounted on the member 86 adjacent each end thereof. As shown in Figure 12, this member I" has an inclined track I I8 formed thereon directly adjacent the flange II2 of member 88. Directly adjacent the track H8 is a steeper track II9. The upper surface of the track H9 is at a slightly lower level than the upper surface of the track II8 so that a shoulder is formed at I20. The vertical surface of this shoulder is curved as indicated. When the screen stencil has moved almost tothe extent of its movement in one direction, the roller III will begin to ride up on the track II8. At. this time, there will be a pile of paint accumulated on the one side of the squeegee. As the roller III rides up on the track II8, the squeegee will be raised since the arm 92 will pivot about the point 95. Continued movement causes the s'queegeeto be raised above the point. The roller III will then drop from the track I I8 onto tend towards each other.
the track II9. At this time, the squeegee will be at the opposite side of the pile of paint but will be spaced above the screen stencil. Now if the screen stencil is moved in the opposite direction, the roller III will contact with the shoulder I20 and continued movement will cause the. roller to move forwardly a slight distance so that it will then roll along track II9. It will drop down ofi the track H9 and,. consequently, the squeegee will again be in contact with the stencil and the paint will again be in front of the squeegee. The spring 6 permits the necessary lateral movement of the roller III in moving from the track II8 to the track H9. The path of movement of the roller is illustrated by the arrows in Figure 12. 1
It will be understood that the screen stencil, although in the form of a segment of a cone, may have a radius as long as desired. It may have a radius a number of times longer than that of the article but it should have substantially the same taper as the article. The wood frame on the stencil will keep the paint from running off the surface. It will also be noted that the article is disposed within the arcuate screen stencil. This is important because the.
silk screen due to shrinkage tends to draw incil. However, this will be advantageous since the article is disposed within the arc and it will merely tend to cause the screen to more firmly contact with the article;
I will now describe themechanismthat operates the clutch lever 43 which, in turn, operates the clutch mechanism that controls rotation of the article and back and forth rotative movement of the screen stencil. This mechanism is illustrated best in Figures 1, 2 and 4. I provide a shelf I2I which is supported in an inclined position on suitable supports secured to the clutch housing I8. This shelf has a cylinder I22 supported on its upper end and a cylinder I23 supported on its lower end. The cylinder I22 has a piston I24 disposed therein which has a piston rod I25 secured thereto which projects from the cylinder. The cylinder I23 has a piston I26 therein having a piston rod I21 that projects from the cylinder. The shelf I2I has a slot I28 formed therein substantially midway between the ends thereof. The upper end of the clutch lever 53 projects up through this slot.
The piston rod I25 and the piston rod I2] ex- The outer end of the rod I25 has an L-shapedlatch I29 pivoted thereto as at I30. The outer end of the piston rod I21 has an L-shaped latch I3I pivoted thereto as at I32. The latch I29 has a notch I33 formed therein adjacent the outer end thereof and the latch I3I has a similar notch I34 formed therein. These notches are adapted to engage an extension I35 on the upper end of the lever 43. The outer end of each of the latches I29 and I 3| is provided with a cam surface I36. Springs I36a are provided for normally swinging the latches downwardly. In order to cause the latches I29 and I3I to swing upwardly about their pivots at the proper time, I provide a pair of plates I3I which support a. pin I38 at one end thereof and a pin I33 at the opposite end thereof. The pin I38 is adapted to be engaged by the upstanding portion I of the latch I29 and the pin I39 is adapted to be engaged by the-upstanding portion IlI of the latch I3I.. The upstanding portion I40 engages the pin I38 when the piston rod J25 is in its outermost position,
-wardly towards the chord of the arc of the stenas indicated in Figure tion I of latch I3I 4. The upstanding porbe in their outermost positions in the cylinders,
as indicated in Figures 1 and 4, as willbe better understood hereinafter. Assuming that the pistons are in the positions in the cylinders illustrated in Figures 1 and 4, it will be apparent that since the piston rod 1251s in its outermost position, the portion I of the latch I29 will be in contact withthe pin I38 and, consequently, the latch I29 will befswung around its pivotto' such an extent that the notch I33 will be disengaged from the extension I35 on the upper end of lever 43. Also, since the piston I 26 is in its outermost position in its cylinder, the notch I34 of the latch I3I will be out of engagement with the extension I35 on the clutch lever 43. Thus, when no article is on the machine, both the latch I29 and the latch I3I will be out of engagement with the clutch lever 43 and, consequently, the clutch will be in neutral position.
However, if air is admitted into the cylinder I22, in a manner to be described later, the piston I24 will move to the opposite end of the cylinder I22 causing the piston rod I25 to be retracted into the cylinder and will permit the latch I 29 to swing downwardly and engage the upper end of the clutch lever 43. The other latch I3I will be caused to engage the upper end of the lever 43 in the same manner by inward movement of the piston I26 in the cylinder I23. However, as will be described more fully hereinafter, when one v of the latches is in engagement with the clutch lever the other latch is out'of engagement with said lever. The initial movement of either of the pistons from the position indicated in Figure 4 causes the latch mechanism to which such piston is connected to become engaged with the clutch lever. Further movement of such piston causes the clutch lever to swing in a corresponding direction and to operate the clutch. Thus, one cylinder and piston mechanism swings the lever 43 in I one direction and the other cylinder and piston mechanism swings the lever 43 in an opposite direction. v A
When the. clutch lever 43 is moved to the left to the extent of its movement, as indicated in Figure 2, the bevel gear 28 will be clutched to the shaft 29. Consequently, the article will be rotated in one direction and the screen stencil will be moved in one direction transversely of the article.
' However, when the clutchlever 43 is moved to the ht .to the extent of its movement, the bevel gear 21 will be'clutched to thev shaft 29. Consequently, the article will then be rotated in an op- Posite direction and the screen stencil will move in an opposite direction relative to the article.
I will now described the various valves and associated parts together with the fluid system which controls operation of the machine. With reference to Figures 1, 2 and l, I illustrate a main air line I42 which is connected to a master valve I43. The main air line. is connected to this valve at one side thereof and a continuation thereof I42a leads from the opposite side' of the valve.
The master valve I43 is mounted below the valve housing 54. It comprises a main chamber' I44 having a piston I45 therein with a piston rod I46 projecting through the rear wall ofthevalvehous- I engages the pin I39 when the piston rod I21 is in its outermost position described subsequently ing. The piston I45 is normally kept in the rear portion of the chamber I44 by a spring I41. The rod I46 has a groove I48 which may be brought into alignment with the ends of the lines I42 and MM connected thereto to permit free passage of air through the line into line I42a, as illustrated in Figure 2. However, because the spring I41 tends to keep the piston I45 in its rearmost position, the groove I48 is normally out of alignment with the lines I 42 and I42a, as indicated in Figure '4, and, consequently, stops flow of air therethrough. The forward wall 'of the chamberl is provided with an air escape opening I49 so that the piston I 45 may be moved forwardly in the chamber I44 by mechanism to be described'.- A duct I59 which leads to the atmosphere and is under the control of a spring pressed ball valve I5I is provided so that when the piston I45moves into the forward end of the chamber I44, the valve I5I will be opened by the suction developed by movement of the piston, and air will be drawn into the chamber I44 through the duct I50. When the piston is permitted to move rearwardly under the influence of spring I41, the air in the chamber I44 will prevent rapid movement of the piston to its rearmost position, due to the fact that the valve I5I will close and the air will be permitted to escape very slowly through a small opening I52. As will be explained more in detail, the piston rod I46 is moved inwardly until the groove I48 aligns with the lines I42 and H211 and is then quickly released so that the spring I41 will gradually return it to its original position. This permits a pufi of air to flow through the main line past the master valve and into line I42a. An oil housing I53 is mounted in the line I42 for feeding oil throughout the fluid system.
The line 942a branches into two branches-which are connected to the cylinders I22 and I23. However, two valves I54 and I55 of identical structure control the flow of air through these branches to the cylinders. A line I421; leads from the line I42, at a pointbefore it reaches the master valve I43, and it branches into two branches which are connected to the cylinders I22 and I23 at the ends opposite to where the branches of the line I420; are connected thereto. The valves I54 and I55 also control flow of air through these branches to the cylinders. Each valve includes a plunger I51. Each plunger is moved inwardly against the force of the spring when the outer end thereof contacts with a cam member I58 secured to the rear surface of the screen stencil supporting member 65. A cam member I58 is disposed adjacent each end of the member 65 and'is a'djustably mounted in an arcuate groove I59 of T-shaped I cross section.
The valve I54 has a transverse duct I54a formed therein and one branch of the line M212 is connected to both ends of said duct. It also has a transverse duct I54b' formed therein and one branch of the line I42b is connected to both ends of said duct. Theplunger I56 of the valve I54 is provided with a groove I540a formed therein and a groove I549b which are adapted to be brought into alignment with the transverse duets I54a and I 54b, respectively, when the plunger is in its innermost position, as indicated in Figure 4. The line I 42a leads from the valve I54 to the piston rod end of the cylinder I22 where it is connected thereto as at IBM. The line I42b leads from the valve I54 to the closed end of the cylinder I23 where it is connected thereto as at I58b.
The valve I55 has a transverse duct I55a formed Z5 therein which has both ends connected to the line I42a and has a transverse duct I55b formed therein which has both of its ends Connected to the line I42b. The plunger I56 of this valve has a groove I556a and a groove I556b formed therein which are adapted to be brought into alignment with the ducts I550. and I551), respectively, when the plunger I56 is in its innermost position. The line I42a leads from the valve I55 to the piston rod end of the cylinder, I23 where it is connected thereto as at I66. The line I42b leads from the valve I55 to the cylinder I22 where it is connected thereto as at I6I..
Itwill be apparent that the lines 211 are connected to the piston rod ends of the cylinders I22 and I23 and that the lines I42b are connected to the opposite ends of the cylinders I22 and I23. Furthermore it will be apparent that when the plunger I56 of valve I54 is in its innermost position, as illustrated in Figure 4, and the master valve is opened by placing an article on the chuck, the air from the line I42 will be permitted to flow through the master valve into the line I420, duct 154:; of valve I54, again through the line I42a, and then into the piston rod end of cylinder I22. At the same time, air will flow through the line I42b from the line I42, through the duct I54b in valve I54, again through the line I42b and into the closed end of cylinder I23. Thus, both the pistons I24 and I26 will be in the positions indi- .cated in Figure 4 if the valve I54 is open and no article is on the machine, as illustrated in this figure. small air escape openings I62 which permit exhaust of air from the ends of the cylinders. at the proper time, as will be explained more in detail hereinafter. When the plunger of the valve I54 is in its innermost position, as illustrated in Figure 4, the plunger of the valve I55 is in its outermost position. Consequently, the transverse ducts I55a and I55b formed therein are closed and flow of air through the line I42a and the line l42b, connected to said valve, is interrupted. Operation of the valves I54 and I55 is controlled by movement of the member 65. When it is in the position illustrated in Figure 4, the valve I54 is open and the valve I55 is closed. However, when it is reciprocated in the other direction to the extent of its movement, the plunger I56 of valve I55 will forced inwardly to open said valve while the plunger l56 of the valve I54 will be in its outermost position and said valve will be closed. At this time, if the master valve I43 is opened by placing an article on the chuck, the air will flow from the line I42 through valve I43, line I420, through transverse duct I554; in the valve I55, again through line M to the piston rodend' of the cylinder I23. The air will also flow from the line I42 through line I42b through the transverse duct I55bin valve I55, and again through line I42b to the closed end of the cylinder I 22. At the same time, since the valve I54 is closed.
' flow of air to the opposite sides of the cylinders through the lines I42a and I42b that are con-" nected to valve I54 is interrupted.
The closed ends of the cylinders I22 and. I23 may be connected together by a valve controlled conduit I42c under the control of a manually operable valve I63 which is normally closed. This valve may be opened in order, at any time, to
' get the pistons in the positions illustrated in Figure 4, butthe valve I54 or I55 must also be opened. p
The main line I42 has another branch- 211 All of the lines are provided with very.
about the pivot point I1 I.
extension I11 with a sharp lower edge.
which is connected to a vacuum line 56a that is connected to a vacuum pump and to the valve 52. This line I42d is under control of a manually operated valve I64 which is normally closed. This valve may be opened and a valve I65 in the suclion line 58a may be closed to permit anunder pressure to flow through the line I42d, line 58a, opening 56, duct 59, opening 66, and then through the passageway 48 formed in the hollow shaft 26, in order to blow out any dirt that accumulates in the hollow shaft.
I will now describe the mechanism that controls movement of the plunger 56 of valve 52 and the plunger or piston rod I46 of the valve I43. This mechanism is illustrated best in Figures 1 and 2. The outer end of the piston rod I25 has a bifurcated member I66 pivotally secured thereto by the pivot, I46. This member I66 has a rearwardly extending thrust rod I61 secured to its upper end. The rear end of this rod I61 is pivotally secured to a lever I68 as at I66. This lever is pivoted to a support I16 as at "I. This, support I16 isbolted to the housing of valve 52. The lower end of the lever I68 has an extension I13 thereon which has a beveled edge. The piston rod I21 also has pivotallysecured thereto at I32 a bifurcated member I14 which has a thrust rod I15 secured to the lower end thereof. This thrust rod extends rearwardly and is pivotally connected to a-lever I16 which is pivoted for movement This lever I 16 has an The plunger 56 has a block I18 (Figure 1) formed on its outer 'end. This block is slotted as at I18. On one side or this block, a dog I80 is pivoted. This dog is normally urged upwardly by a spring I8I but its upward movement is limited by a pin I82 engaging an extension-on its outer end. The upper'edge of this dog is curved as at I83 and has a sharp corner I84 at its upper and outer edge. A second dog I85 of identical structure is-pivoted on the opposite side of the block. The corner I84 of the dog I86 is adapted to be engaged slightly by the extension I13 of the lever I 68 when the lever swings in such a manner that the lower end swings rearwardly. However, the dog I86 will pivot downwardly slightly in order to permit passage of the extension I13 and then pivot upwardly so that the point I84 will be in front of the extension I13. The lever I16 :1
and the dog I85 will cooperate in a similar manner.
- The block I18 has a third dog I66 (Figures 2 and 4f pivoted thereto and disposed in the slot I19. However this dog is reversed relative to the others and is pivoted for upward swinging. -It cooperates with an extension I81 on a pivoted lever I88 which is pivoted at the rear of the valveposition. During movement into such outermost position the dog I66 engages the extension I61 on the lever I68 and causes said lever to swing about its pivot forcing the piston rod I46 iorwardly and operating the valve I43 to permit a pufi of air to how into the line, I42a. The plunger 56 is moved into the position indicated in this figure merely by placing the article on the chuck,
through the medium of the rod When the plunger is moved rearwardly a sumcient distance,
the end of the extension I81 will slip off the cor her of the dog I85, permitting the upper endof lever I88 to'swing forwardly and allowing the rod' I45 and piston I45 to move rearwardly closing the valve I43. When the parts are in the positions illustrated in Figure 2 the extension I11 on lever' I16 will be out of engagement with the dog I85. The extension I13 on the lever I58 will be in its rearwardmost position in engagement with the dog I83.
If the piston I24 is'moved to the other end of the cylinder from the position indicated in Figure 2, the rod I 51 which is connected to the. piston rod I25 will cause the upper end of the lever I58-t0 swing rearwardly. The extension I13 of the lever is in engagement with the dog I89 and, consequently, it will move the plunger 55 forwardly until extension I13 swing s t'osuch a point that it will be disengaged from the dog. If the piston I26 is movedv to the opposite end of the cylinder I23, piston rod I21 will move to the right (Figure 2) and the rod I15 will cause the lever I16 to swing rearwardly until extension I11 snaps'behind dog I 85.
I will now describe the operation of the entire apparatus. Assuming that the various parts of J the operating mechanism of the machine are in the positions illustrated in Figure 4, it will be apparent that there is no article in position on the machine and that the member 55 has been,
- from the upper end of the clutch lever 43. The
piston I24 will also be in the position indicated -in this figure because when the valve I55 was previously opened by movement of the member 55 into the opposite position from that indicated in this figure, air flowed from the constant pressure line I42, through line I'42b, through valve E55 into the closed end of'cylinder I22, forcing the piston Q24 into the position indicated in this figure and, consequently, disengaging the latch I 29 from the Thus, with 29 will not be rotated and, consequently, the
' member 65 will remain stationary and the chuck will be stationary.
However, as soon asgan article is placed on the chuck, the machine will again be started in operation. In positioning the article'on the chuck, the rod 5| is forced rearwardly. This moves the plunger 56 rearwardly. This causes communication to be established between the vacuum line 58a and the passageway 48 in the'hollow shaft 29. Consequently, the vacuum force will hold the article in position v on the chuck. Rearward movement-of the plunger 55 also operates .the valve I43 through the medium of lever I88 and when the valve I43 is opened, air flows for a short period from the line I42 intothe line l42a until the valve; I43 gradually reaches closed position which will occur automatically. Since the member 55 is in such a position at this time thatthe' valve I54 is open, the air will flow from the line I42a through the valve I54 and into the piston rod end of the cylinder I22. This will force the grown piston I 24 into the opposite end of the cylinder which will cause the latch I29 to engage the upper end of the clutch'lever 43 and will swing this lever to the left, asindicated in Figure 2. This causes the bevel gear 28 to become clutched to the shaft 29 and drive the shaft in one direction. When the shaft is driven, it immediately causes movew ment of the member 55 through the medium of gear 53 and rotation of the article in one direction. The valve I 54 will be immediately closed.
The member 55 will continue to move until the cam I58 at the opposite end thereof strikes the plunger I55 of valve I55 and opens this valve. At this time, air will flow from the line I42, through line I42b and through valve I55 into the closed end of cylinder I22 and again force the piston I24 to the position indicated in Figure 4 which causes movement of the clutch lever 43 again into the position indicated in this figure and the latch I29 to be disengaged therefrom. The clutch will again be in neutral and rotation of the shaft 29 and, con--' sequently, movement of the member 55 and rotation of the article ceases. Movement of the piston I24 back to the position illustrated in Figure 4 causes the rod I61 connected thereto to move rearwardly which, in turn, causes the lower end of lever I68 to swing forwardly. Since, as indicated in Figure 2, the lower end ofthe lever is in engagement with the dog I89, before the piston starts to move back into the position indicated in Figure 4, such movement of the piston also causes forward movement of the plunger 55 which, in turn, causes forward movement of the rod 5| and also cuts olf the vacuum supply to the chuck. The. forward end of the rod 5I will strike the bottom of the tumbler and will automatically disengage it from the chuck so that the operator may remove it. Forward movement of plunger 55 also causes the extension I81 on member I88 to again engage dog I86, as shown in Figure 4. Q
In order to again start the machine in operation it is necessary to place another article on the chuck. Thiscauses the vacuum chuck to again be operated to hold the article in place.
Also, it causes opening of the valve I43 for a short period again. Since, however, valve I55 is open and valve I54 is closed at this time, the air will flow for a short period into the line I42a, through valve I55 and into the piston rod end of cylinder I23, forcing the piston I26 into the opposite end of the cylinder from that indicated in Figure 4. This causes the latch I3I to engage the upper end of the clutch lever 43 and to swing the clutch lever to the right (Figures 2 and '4). This causes the gear 21 to be clutched to the shaft 29 and brings about rotation of the shaft. Rotation of the shaft causes rotation of the article about its axis and movement of the member 65 v in the opposite direction which again closes valve I55. Movement of the piston I26 into the end of the cylinder I 23 opposite to that indicated in Figure! also causes rearward movement of the rod I15 (Figure 2) and, rearward swinging of the lever I15. The lever will swing until it becomes engaged with the dog I85. The article will continue to rotate and the member 55'will continue to move until it again reaches the position indicated in Figure 4 at which time the valve I54 will again be opened. At this time air will flow from line I42, through line I42b, through valve I54 and into the closed end of cylinder I23 anda'gain force the piston I25 back to the positionv indicated in Figure 4. This causes the clutch lever ill 43 to move back into neutral position and, consequently, rotation of shaft 29, rotation of the article, and movement of member 65 ceases. Movement of the piston I26 back into the position indicated in Figure 4, due to the engagement of lever I16 with dog I85, causes forward movement of plunger 56 which closes the vacuum line and also moves the rod 5| forwardly to cause the article to be disengaged slightly from the chuck. If an article is again placed on the chuck, the valve I43 will be opened for a short period and the piston I24 will again move to the opposite end of the cylinder from that indicated in Figure 4 and rotation of the article and movement of the member 65 will again occur.
The vents I62 are provided at the various places indicated to permit exhaust of air from one side of the pistons when air is supplied in the cylinders at the opposite side of the pistons so as not to interfere with movement of the pistons. The pistons are normally in such a position that the clutch is in neutral, as indicated in Figure 4, and the vents permit movement of the pistons into such positions. However, the vents are so small that during the time air under pressure is forced through the lines in which they arelocated, only a comparatively small amount of the air under pressure escapes. 'Thevents also prevent movement of the pistons by accumulated air which might leak past valves I54 or I5 5 when they are closed.
It will be apparent that one cylinder and piston mechanism causes the clutch to be operated in such a manner that it rotates the article in one direction and moves the member 65in one direction. The other cylinder and piston mechanism causes the clutch to be operated in such a manner that the article will be rotated in an opposite direction and the member 65 will move in an opposite direction. The two cylinder and piston mechanisms operate alternately, as previously described.
As previously stated, an article is finished during each movement of the screen stencil in one direction. The article and the screen stencil will be in rolling contact with each other along a single line. The screen stencil moves relative to the squeegee and, therefore, the paint will be forced through the stencil onto the article along a line of contact that progressively changes.
When the machine is used for decorating tapered articles, such as the tapered article illustrated in the drawings, the screen stencil 81, as previously stated, is in the form of a segment of a cone. screen stencil forms a part should be approximately the same as the taper of the article. The end of this screen stencil which has the greater radius of curvature lies adjacent the curved mem-- ber 65. The center of curvature of the member 65 should lie on the axis of the screen stencil. The opposite ends of the screen stencil will be of diflerent radii of curvature and the difference between the two radii of curvature ofthe two ends will depend upon the extent of taper of the article. of curvaturelying on the axis of the screen stencil whenthe' member 65 is reciprocated, the screen stencil will move-in a rotary path, first in one' direction and then the other, about the axis line of the screen stencil. As previously stated,-however, tilting of the member 65 also tilts the screen stencil and, consequently, tilts the axis of the screen stencil. The axis of the screen stencil, which is the axis ofthe cone ofwhich it forms a The taper of the cone of which the- Because the member 65 has its center.
part, should be tilted to such an extent that it intersects the axis of the article at a point which will be the common apex of the cone of which the stencil forms a part and the cone which would be formed by continuation of the sides of the article.
As previously stated, if the machine is being used for printing on articles of one taper and then it is desired to use the machine for printing on articles of a substantially different taper, it is necessary to replace the screen stencil with a screen stencil of substantially different taper. The center of curvature of the member 65 should always be on the axis of the screen stencil so that when .the member 55 is reciprocated the screen stencil moves in a rotary path about its own axis. Each time a screen of different taper is placed on the machine, it is necessary to adjust the member 65 to a different tilted position in order to change the inclination of the axis of the'screen stencil so that it will intersect the axis of the tumbler in the manner previously described. For example, if it is desired to print upon an article of considerably sharper taper'than the one illustrated on the machine in Figure 2 of the drawings, it is first necessary to replace the screen stencil with one having substantially the same taper as the new article. However, it will also be necessary to tilt the member 65 rcarwardly or to the "right (Figure 2) to a greater extent than that illustrated in Figure 2 in order to tilt the axis of the screen stencil so that it will intersect the axis of the tumbler at the c'ommon apexof the cone of which the screen stencil forms a part and the cone of,which the article forms a part However, if it is desired to print upon an article of substantially less taper than that illustrated in Figure 2, or in other words, a more nearly cylindrical article, it would be necessary to replace the screen stencil with a stencil of substantially the Because of the fact that the screen stencil is merely supported at one end, it is much easier to feed the article beneath the stencil than would be the case if supporting structures were provided at both ends of the stencil. The segmental screen stencil is supported at its larger end and the article may be fed therebeneath from a point at the opposite or smaller end. This facilitates positioning of the articles beneath the stencil and eliminates the necessity of having conveyers for bringing the articles beneath the screen stencil.
In Figures 13 and 14 I show a modification of my machine. All the mechanism of this machine is the same as that in the preferred form with the exception of the mechanism for reciprocating the screen stencil and the valve mechanism and operating mechanism therefor which is employed for controlling application of vacuum to the vacuum chuck.
As shown in Figure 13 a motor I2a is provided which drives -aworm and gear unit Ma. The unit I4a drives a shaft I90 through the medium of belt and pulleys drive I9I. The shaft I90 has a disk I92 keyed on its forward end. A rod I93 is pivoted eccentrically. to the disk at I94.
that carries the gear 63 which is in This rod I93 is pivoted at I95 to one end of the stencil supporting member 65. It will be apparent that when the disk I 92 is rotated, it will cause reciprot cation of the member 65. It will also cause rotation of the article which is mounted on a shaft engagement with rack 64 carried by member 65. c
The shaft I90 has a disk I96 keyed on the opposite end thereof. This disk has a rod I91 cc centrically pivoted thereto as at I 98. The opposite end of this rod is pivoted at I99 to and 200 mounted for movement longitudinally of itself. These cams 20! are adapted to engage the outer end of a plunger 56a. This plunger 56a controls a valve 54a substantially like the valve 54 previously described. This valve controls application of vacuum to the vacuum chuck. The plunger 56ais connected to a rod 5Ia which corresponds to the rod 5| of the preferred form of my machine.
It will be understood that the screen stencil .will reciprocate even when an article is not in position on the chuck. In order to keep the squeegee out of contact with the stencil during reciprocation thereof when an article is not in position on the machine in order to lessen wear on the stencil, I provide'the structure to be now described. This structure embodies a bell crank lever 202 pivoted to a support as at 203. This bell crank lever has a roller 204 adapted to, contact with the outerend of, plunger 56a. The p upper end of a lever 202 has a rod 205 slidably 'mounted in an opening therein. A spring 206 is provided around the rear end of rod 205 which tends to swing thelever 202 downwardly around its pivot so that roller 204 will be in contact with the e'nd'of plunger 56a. The forward end of this red is pivotally connected to a finger 201 as at 208. The finger 201 is pivotally connected at 209 to an upstanding support 210 pivoted at 2 I I. The
-finger 201 is adapted to cooperate with a fiat I member 2I2 on the rear. end of the squeegee supporting arm 92a.
When an article is in position on the machine,
' the rod 5| a and the plunger 5611 are pushed rearwardly. This causes the lower'end of the lever 2.02 to swing upwardly and the upper end thereof to swing rearwardly. Consequently, therod 205 and the finger 20'I-will be drawn rearwardly. This causes the finger 20'! to be retracted from over the member 2I2 and, consequently, the arm 92a will be permitted to swing downwardly so that the squeegee will contact with the screen stencil. However, as soon as an article is removed from the machine, the -rod 5Ia and the plunger 56a will be in their forwardmost positions, which will cause the finger 201 to again move forwardly over the member 2I2 causing the arm 92a to swing upwardly'and the squeegee to,
be raised out of contact with the screen stencil. Thus, when an article is not'in position on the machinathe squeegeewill be out of contact with the screen stencil. I
In Figure I have-illustrated a poppet valve unit 'which facilitates operationof the control for the vacuum chuck and operation of the master valve I43. In the form previously described, when the article is positioned on the chuck, the rod 5| must be pushed rearwardly with sufliicient force to cause the plunger 56 to move rearwardly to apply suction to .the chuckand the member I36 to swing the lever I88 about its pivot and force plunger I46 forwardly, thereby opening This rod carries a pair of spaced cams I.
valve I I43. This device works very satisfactorily. However, it maybe desirable to provide mechanism for facilitating operation of the valve for' mechanism illustrated in Figure 15 for facilitating opening of the valve I43.
A plunger 56a which corresponds to plunger 56 is provided but in this instance the rod 5Ia extends rearwardly through the plunger. The rear end of this rod has a sleeve 2 I3 adjustably threaded thereon. This sleeve is slidably mounted in a support 2I4. The sleeve 2I3 has an annular shoulder 2I5 on its forward end. A compression spring 2I6 surrounds the sleeve 2I3 and its forward end abuts the shoulder 2I5 while its rear end abuts the support H4. The plunger 56a and associated parts are exactly the same in all other respects as the plunger 56 and associated parts with the exception that the member I860, which corresponds to member I86, is mounted on the plunger 56a in such a manner that it will not pivot thereon. The member I88a, which corresponds to the member I88 and is pivoted to the plunger I4'na of the valve I43, is adapted to have its upper end I8Ia engaged by a shoulder I81?) on the member I86a. Member 3811 is also pivoted at I88b A poppet valve 2 I1 is provided for operating the valve I 43. Thispoppet valve has a chamber 2I8 which is alwaysv filled with air. under pressure through the medium of a line I 42d running from the main line I 42. This valve has a plunger 2I9 disposed therein and a spring 220 normally urges this plunger forwardly or in closed position. The forward end of the plunger projects from the 'is bevelled at its upper end as at 221. A com- 'pression spring 228 mounted in member 22I normally urges the pin 226, shaft 223 and the rollers V 225 upwardly so that they are always in engagement with cam surfaces 229. The upper end of the pin 226 is adapted to be engaged by the shoulder 2I5 on the sleeve 2I3 which is carried on the rear end of the rod 5la. A line M311 is connected to the chamber I44 of valve I43 behind the piston 2 I45 and is also connected to the poppet valve at a point in front of the valve seat 2I9a of the poppet valve 2I1. A portion 2I9b on the plunger-2H is normally seated on the seat 2I9a by the spring 220 to prevent the air from flowing from chamber 2"! through line I43a into chamber I44.
In the operation of this mechanism, assuming .that the parts are in the positions indicated in .Figure 15, if an article is placed on the chuck it will cause the rod 5Ia to move rearwardly and to slide relative to thevplunger 5611. When the rod moves rearwardly the shoulder 2I5 on sleeve 2I3-will engage the upper end of the pin 226. This ,will cause the member 22I to swing about the pivot 222 which, in turn, will cause the rollers to ,ride downwardly along the inclined cam sur-,
faces 229. The member 22I will contact with the end of plunger U9 and will move the plunger rcarwardly allowing the air to flow from the chamber 2I8 through line I43a'\to the chamber I 44 which will movcthe piston I45 forwardly wardly on the cam surfaces 229 a sufficient distance to draw the pin .226 downwardly and to disengage its upper end from the shoulder 2I5. At this time, the member 22I will again swing forwardly since the spring 229 will urge the plunger 2I9 forwardly. Furthermore, the poppet valve will be closed. Movement of the pis-, ton I45 forwardly also causes the plunger I46a to move forwardly and the member H381; to pivot around the point I88b so that its upper end swings rearwardly. The upper end I8'Ia engages the shoulder IBIb and forces the plunger 56a rearwardly. This connects the vacuum line to the vacuum chuck, as described in the other form of the apparatus. The plunger 55a will be returned to its forwardmost position by the mechanism previously described for returning the plunger 56 to its forwardmost position. valve I .3 will automatically close after -a short interval. The rod 5I will remain in its rearwardmost position until the plunger 55a is returned to its forwardmost position since the vacuum force of the vacuum chuck is sufficient to resist the tendency of the spring 2I6 to move the '-rod into its forwardmost position. However, as
soon as the vacuum supply to the chuck is interrupted by movement of the plunger 55a to its forwardmost. position, the spring 2I8 will move the rod into its forwardmost position. During movement of the rod 5-la into its forward position the shoulder 2I5 will strike the upper end 221 of pin 226 which will cause/the pin to move downwardly slightly and permit the shoulder to pass.
Thus, it will be ap arent .that with this mechanism, the rod 5I a may be moved rear: wardly very easily since the air pressure performs-the functions of moving the plunger I451:
ing at the ends of the stencil. As shown in Figure 20, I provide a. unit 230 at each end of the screen stencil 81 for this purpose. Each of the units 230 comprises a main casting 23I which is vertically adjustable on a supporting arm 232 by means of a bolt and slot connection 233. The otl 7 end of the arm 232 is adjustably secured by a bolt and slot connection 234 to a bracket 235 fastened to the screen stencil supporting member 65. The casting 23I has upwardly extending portions 236 at each side having slide 3. sfcrmed therein in which slide members 231 operate. These slide members 231 are part of unit 238 which is, consequently, vertically adjustable relative to the casting 23I. The unit 238 has a pair of upstanding spaced arms 239 between which is pivoted, as at 240, a bell crank lever 24I. One arm 242 ofthis bell crank lever engages a pin 243 extending between the upp "ads of the arms 235 of casting 23I. The othe. o 244 of the bell crank lever has a latch 245pivoted to the lower end thereof as at 246.
I and open valve I43. Only a puff of air will be permitted to flow past the poppet valve since it will close as soon as'the rollers 225 ride down- The or towards the center of the screen stencil.
This latch 245 is adapted to-engage 9. lug 241 on the unit 238. A spring 248 is interposed between the arm 242 of the lever and the latch 245 and normally tends to spread these members apart. A spring 249 is interposed between the base of the unit 238 and the base of the casting 23I and this spring normally tends to cause the unit 238 to slide upwardly on the casting 23I.
The unit 238 carries a pair of sleeves 259 in which a pair of rods 25I are mounted for longitud'fnal movement. These rods have their rear ends connected together by a substantially U- shaped'bracket 252. A pair of coil springs 253 are provided in surrounding relation to the forward ends of rods 25I. The forward ends of these rods carry an auxiliary squeegee member 254. The springs 253 are disposed between the member 254 and the ends of sleeves 250. These springs normally tend to urge the rods 25I and, consequently, the squeegee member 254 forwardly A plunger 255 is also slidablymounted on the unit 238. This plunger has its rear end contacting with the lower end of the arm 244 of the bell crank lever 24I. Q
The members 254 will normally be in the position indicated in Figure 19 where they are spaced from the ends of the screen stencil. These auxiliary squeegees 254 extend substantially the entire width of the screen stencil. The blade of eachmember 254, when the member is in this position, will be out of contact with the screen stencil because the latch 245 is released from lug 241 on unit 238,by contact of member 252 with latch 245, and the spring 249 urges the unit 238 upwardly on the casting 23I. However, if the screen stencil is movedto the left until the squeegee I02 contacts with the member 254 at the right hand end of the screen stencil, the member 254 will be moved into the position indicated in Figure 18. During movement into such position,
the member 254 will strike the plunger 255 which will cause pivoting of the bell crank lever 24I around the point 249. Since the end of the arm 242 is in engagement with the pin 243 carried by casting 23I this will cause the unit 238 to slide downwardly relative to the casting against the force of the spring 249 until the latch 245 snaps behind the lug 241 which will hold the unit 238 in this position on the casting 23I. This will force the blade of the member 254 into contact with the screen stencil as indicated in Figure 18. Now if the screen stencil is moved towards the right, the blade of the member 254 will scrape the paint inwardly towards the center of the stencil because the springs 253 will force the member 254 inwardly towards the center of the screen stencil. During th s inward movement of the member 254 the blade is in contact with the screen stencil. When the member '254 nears its inwardmost position, the member 252 will strike the latch 245 and cause it to be released from the lug 241 which will permit the blade of member 254 to move upwardly away from the screen stencil due to the fact that the spring 249 will urge the unit 238 upwardly, which in turn causes bell crank lever 24I to pivot around the point 240. The plunger 255 will also be forced inwardly by movement of the bell crank lever.
Thus, during the inward movement towards the center of the screen stencil, the blade of member 254 will be in contact with the screen stencil and will, consequently, scrape the paint towards the center of the screen stencil. However, during movement of the member 254 to-
|Citing Patent||Filing date||Publication date||Applicant||Title|
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