US2894451A

US2894451A - Screen printing machine

Info

Publication number: US2894451A
Application number: US607867A
Authority: US
Inventors: Landesman Eugene
Original assignee: Individual
Current assignee: Individual
Priority date: 1956-09-04
Filing date: 1956-09-04
Publication date: 1959-07-14
Anticipated expiration: 1976-07-14

Description

July 14, 1959 E. LANDESMANl SCREEN PRINTING MACHINE 5 Sheets-Sheet l Filed Sept. 4, 1956 EUGENE LANDESMAN ATTQRNEY July 14, 1959 E. LANDESMAN SCREEN PRINTING MACHINE 5 Sheets-Sheet 2 Filed sept. 4, 1956 INVENToR.

EUGENE L AN DESMAN @QJ-fs 'N M ATTORNEY July 14, 1959 E; LANDESMAN SCREEN PRINTING MACHINE 5 Sheets-Sheet I5 Filed sept. 4, 1 956 INVENTOR. BYEUGENE LANDESMAN @gum IQUA vrATTORNEY July 14, 1959 E. LANDESMAN SCREEN PRINTING MACHINE 5 Sheets-Sheet 4 Filed Sept. 4, 1956 INVENToR.

EUGENE LANDESMAN BY @911A w. K

AITORN EY July 14, 1959 E. LANDESMAN v 2,894,451

SCREEN PRINTING MACHINE Filed sept. 4, 1956 5 sheets-sheet 5 BYEUGENE LANDESMAN @drm/ 1 ATTORNEY 'at the forward end ofthe swing frame.

United. States Patentf- 4' Eugene La ndesrnan,l University City, Mo.

'sleiiesirl des. 'serrer @meer adem drier-...lm

This invention relates in general to printingv `apparatus stutzig"rlnqrev particularly, """en printing" mahin'es'if the presen inv/,enti i misto prevideissereen ,e maehiueiineorporatiee. squeegeeeberide, roel@- f, A, .l me 11's fbsvviiigirgsame between lowered or printing positiori 4and raised or'fworkl' lee deposition. infiimed re` orrffo trevel of the sqdeegee.' Itis another object offth J rnventioii to jgarovifder means for reciprocal travel of. aY squlejegee along aswin'g frame with means for ertfectigng increase f speed during travelmooedireodom It is a further. oeieet of this invention to Provide e reoiproeally rrrovira7 mlm Carrier. adopted for. edsevvise engagement vvitllf e soreers, or." sledeil during movement iii one direotiod; whiohs llos. ely Suspended for fellowtng the. surfsoe oorrtour of the. screed; which is. Provided with lateral paint trapping elements; mrd Wllieh SS constructed as to. Serve. as. CIldllClQl for. Stelle Chelge op the. screen- It is a further object et 4the present invention to. pro.- vide means. for regulating the elliellt 0f trat/el (if lll@ squeegee so that the machine may, with equal facility, eoonomioally and rapidly aeoommodatework oi .varying Cllllflensions.

rt is anadditional objeet to. provide a screen printing machine Comprising ya piyotally mounted soreen or ste'n'cil connected to a swing frame for movement therewith. A

It is another object of this invention to provide a screen printing maehine lincorporating a 'lever operated system for maintaining the swing frame in upward position to permitready` access to the'machine for repair 'and the like during operation thereof.

rA still further-'object Aoi this invention is to provide a screen printing machine which is'durable in "construcltion, reliablein operation, economical to produce; and' the use of 'whiehi does' not 'require khighly skilled -u-ysv y. Mr si z .Hfs-, .f .v n. @fnv "Tlsese'eod other ,detailed .objects are obtained by the e ld he aoefomodyiogdrawmglsftdve Emyrel is e side view of e semen priming maghi/ne eorfrstrlsfed in ,eieooriare with md .mbodyiig' the yp'ieseri invenn.. Figure 211s a top plan view .showing the cross-.head

Figure 3 is a horizontal transverse section taken on the line 3-3 of Figure 1.

Figure 4 is a` vertical transverse section taken on the line bf-Figllr." i 'I U Figure 5"is"ra"`partial top plan view taken on the line s rearward ood ...view of the mamme l ....ewrof themabhin: irrigui-e ,s 'is verdeeltransverse-Seddon .takers on .the im? .fifgigillfzw i u i I d x I.

' ice? Figure 9 is.. e. toppled vieu with, the. swirls. frame, m tvdpiqn:

Referrmanovy by refererl, Characters to the. draw.- ings, A designates, e. sorfeeo 'prio 'de moslims 'eomprismej a supportv structureinlicated"generally atil, having relatively exledded rectangular. bese" '2.,' mounted" on, casters c, and an upper portion formedx of par-llel'sidt'f; members e, eomreeted. by e erofss member 31s' Seildfbase mrd opper portion. lzemg 'imereormeeted ley, various serif, port elements 4s seid ripper. Peillon 3.1?.ei1l-l`feerlle irl. a generally, forwardly; odset mnner will? resrest. to'. said base 2- T lregforrvard eed of. said upper rum Prof reefs. beyond rire forward eed. of baise. 2. whsle the reste. ward. end of parallel side` members 3 dre disposed. elle* stamially above the Central or. medial Portion of. basel.- Supfport members. 4l oonslst of .various drrights, erases and the like; and are oli any suitable steek., such es angle. iron, etc. Eixed upon said. side members a is a bed. 915 platen 5 forA world-renewing pumosesf While mounted. on said side members 3: at their` rearward ends are aligned pillow blocks 6. for journaling therein Qi. 'e Shaft .1,'presented 'transversely of said side members 3., upon which is secured a pair of'spaced apart support arms 8, 8'. Said arms '8, 8' are in normally inclined `relationship to the vertical, extending both above and below side members 3 and bein'g rigid atthe'ir upper ends with the central 'portions of side elements 2, 9 respectively ofA a rectangular, swing frame 10', the ends of` which Vare de2 nedby rearward and forward "cross members 11, 11'.. Said swingfra'me 10 is ths 'adapted upon rotation'of shaft 7 or 'by rocking oi arms 8, 8', for swingablernove'- ment between 'horizdntal br downward position, wherein it will b'e plana-rwise parallelto bed'S, and tilted orlup ward position' (las shown lrespectively in full and dotted linesin Figure l); thereY being' means presently"dscrib`ed for limiting',r the degree lofroclfo'fsaid"frame 10:The rearward endportio'n 'of' saidfswing'frame 10 extends beyond the rearward 'edge of 'said members 3 'of support structurel, vand 'will extend therebelowwlien iii upward .i ,',V v. Y.. ft

""Pivotally mounted upon bed 5 forwardly of pillow blocks '6 is tnerearwardedge 'portion 'or the frame 12 for supporting fa' screen or l'stencil '"1'2 of "conventional eharaeteran-d havng'rat its forwrd'end a bracket ato whichis s`e'c`s'1ired'tli'e l'owerend'o'f arelat'ivelyshohrtichain or lother eXible member b,"'th'el upper endfwhich's' engaged totheifend portion Aor anra'rnr dektendin'g forwardly vfroirffront"cross 'member '11 of'swing fra'rne 10 whereby'si'dscren'il wi-ll' b`e -swur'fg abqit the real"- wardedge rtvframe 12 with' respeet `"robedis upon rocking movement of's"aid"'swir'1g frame 1'0; Said chain `1`4 is of'greater"lengtlftlfan'thedistanceb'etweeii swing frame' 1Q' and bed' 5 'when the former is' in 'horizontal position 'so"`tliat thereir'1"s'cren fr anlfeA 12 will"'b`e"si1p portedupon bed 5 s''as fo' present".sc'ree'l'i- 1'2"ir1""pe'ra tive position with respect' to aiw'rkipiec'e' w."Wi'tl 1'swin`g fr'ame I0 in vr'ijpwrard psi'tion,""scren` 1,' 2 will'be raised atiit's' forward'endfronbeds to :permit thewithdrawal of completed"w0rk`therefrmaid"the'disposition Atli m of e torio meedeed el. me

non?" Side elements .9 97 are Preferably of eiserne with' their fledged lesive idieteiillyeidly fo fo d ".13" odell .los Pyfaislly engaged the forward end portion'of an elongated connecting rod or pitman 18. The other or `rearward end of connecting rod 18 is swingably secured to a crank arm 19 fixed on the upper end of a vertically presented shaft 20 of a speed reducer 21, the latter being suitably supported from

cross members

22, 22 extending between side elements 9, 9' in the rearward end section of swing frame 10.

j Speed reducer 21 incorporates a shaft 23 axially perpendicular to shaft 20 and projecting laterally toward one side of frame 10; said shaft 23 being operatively connected by drive belts 24, 25 with the drive shafts 26, 27 of motors 28, 29 respectively. Said motors 28, 29 are mounted on swing frame 10 and are respectively disposed forwardly and rearwardly of speed reducer 21. With reference to Figure 8, it will be seen that the relationship of the pulleys whereby drive belt 25 connects motor 29 to speed reducershaft 20 is such as to cause said latter shaft to be operated at a greater rate of speed when operatively connected to motor 29 than when driven by motor 28. Motor 29 is adapted for intermittent operation, whereas motor 28 is connected for constant operation. Thus, the speed of rotation of shaft 20 will be influenced by motor 28 except when motor 29 is energized and thereon, due to lthe particular drive belt-pulley arrangement, an overriding,l effect will develop so thatv shaft`29 will, during such period of energization, rotate at an increased rate. It is obvious that both motors 28, 29 may be of identical capacity and speed to effect the desired differential result; or a single dual speed motor may be utilized, or if desired motor 29 may be of the high-speed variety with motor 28 relatively slower. Disposed adjacent speed reducer 21 is a switch 30 for motor 29, including a resiliently mounted arm 31 *bearing at its upper end a cam member 32 for engagement by a switch operating plate 33 fixed on shaft 20 beneath crank 19. Switch operating plate 33 is of arcuate character,` and of such radial extent as to maintain switch 30 in closed, circuit-making condition during movement of shaft 20 through a corresponding arc of its path of rotation. Said switch operating plate 33 is mounted on shaft 20 with respect to crank 19 so that switch 30 will be engaged during the interval said crank 19 moves from a substantially forwardly directed position to a substantially rearwardly directed position, or wherein the same in cooperation with connecting rod 18 causes rearward travel of cross-head 13. Thus, it will be seen that motor 29 is cut in when cross-head 13 is disposed at the forward end of swing frame 10 for travel thereof rearwardly at a relatively rapid rate.

Cross-head or carriage 13 mounts on its under surface alpair of spaced apart, parallel arms 34, 34 which ex- Ytend forwardly thereof with each being provided with a series of aligned apertures 35 for selected downward extension therethrough of an elongated bolt 36 which projects through `a bore in a mounting block 37 and having an adjusting nut 38 engaged on its lower end. .Above each block 37, a compression spring 39 is en- `cirlingly disposed about each bolt 36, bearing at its lower end against the upper surface of the related block 37 and at its upper end against a nut 40, whereby blocks 37 may be resiliently and vertically adjustably main- ;tained on bolts 36. Secured pivotally to the opposite side Afaces of each block 37 are the arms of a yoke-type bracket 41, the central portion of which is fixed to the forward face of a squeegee bar 42, the latter being thereby presented transversely of said swing frame 10 and forwardly of and beneath cross-head 13 for movement therewith; said squeegee bar 42 being made -of any suitable material, such as wood and the like, and having a groove formed in its under surface for receiving a downwardly projecting squeegee 43. Threadedly engaged in each block 37 and extending therethrough is a plurality of abutment members or screws 44in axially normal re- Y lationship to the associatedA bolt 36 which at their rearward ends are presented to abut the forward; face of squeegee bar 42 so that yby the selected adjustment of the same, squeegee bar 42 may be lockingly maintained at a desired degree of inclination to the vertical or at ther correct angle for the particular paint, ink, or other coloring matter utilized and the particular character of the: screen 12 so that a well delineated print of maximum` definition will result.

Mounted on the under surface of cross-head or carriage 13 are the rearward end portions of a plurality of spaced sets of guide rods 45, being arranged in pairs with their forward end portions bent forwardly and downwardly beneath cross-head 13 and spacedly and rearwardly of squeegee bar 42, with the lower ends thereof terminating upwardly of the lower end of squeegee 43. Slidably received within guide rods 45, being presented at the angle determined thereby, for upward and downward movement therethrough, is a paint carrier 46 .comprising `a preferably at metallic sheet, having at its lower side edges forwardly and slightly downwardly turned wing-like members 47, 47'; there being stop blocks 48 mounted on each pair of guide rods 45 to limit upward movement of Ksaid paint carrier 46. Paint carrier 46 is substantially co-extensive with squeegee bar 42, although wings 47, 47 extend laterally therebeyond, and centrally is suitably engaged to the lower end of a short rod 49, the upper end of which is engaged to Ithe lower end of an angulated arm 50, the other end of the latter is pivotally mounted on a lug 51 extending laterally from the end face of T-block 16, whereby said arm 50 is adapted for swinging in a vertical plane, transversely of swing frame 10. Said arm 50 proximate its angle restingly abuts on its under surface a pin 52 projecting forwardly from one end portion of a dog 53 rockably secured on the forward face of block 16 for swinging movement in a plane parallel to that of arm 50.` The relative weight of paint carrier 46 will bias arm 50 downwardly whereby through engagement of the same with pin 52 dog 53 will be urged into downwardly swung position of its pin-bearing end (see Figure 5) so that paint carrier 46- will descend through guide rods 45 for engagement on its lower edge upon screen 12. Thus, in this position, the weight of paint carrier 46 will bear against screen 12 to assure iirm contact therewith. Dog 53 is so mounted with respect to block 16 that when in horizontal position (wherein paint carrier 46 will be in raised state) its upwardly presented edge will be flush with the upper surface of block 16 and hence be disposed for extension thereover of the forward end extremity of connecting rod 18. Therefore, as connecting rod 18 follows its prescribed, reciprocating path of movement consequent to operation of crank 19, it will periodically engage the upyper surface of dog 53 so as to return same ,to horizontal position from rocked position resulting in lifting of paint carrier v46, retaining same in such state forA an interval, and then losing engagement with dog 53 to thereby effectively release paint carrier 46 for descent thereof (see Figures 4 and 5). There is also provided upon the upper surface of cross-head or carriage 13 for extension above the forward end of block 16, a hold-down unit indicated at 54, for maintaining the forward end extremity of connecting rod immediately upon block 16 to assure reliable coaction thereof with dog 53.

Referring to Figures 2 and 9 it will be seen Ythat connecting rod 18 will engage dog 53 for maintaining paint carrier 46 in elevated relation above screen .12 during rearward travel of cross-head 13, and will hence be` out of engagement during forward travel of cross-head 13 permitting paint carrier 46 to be thereby in contact with screen 12 during such portion of the cross-heads reciprocal movement. ln lowered position paint carrier 46 is caused to traverse screen 12 in an edgewise scraping manner for forcing the paint or other color material on ksaid screen toward the forward end thereof for ultimate return by sweeping action of squeegee 43 in its operative or printing stroke. Due to the attitude of paint carrier y46 with respect to the upwardly rocked :screen :12' .the `.paint 4will be lifted, as 4it were, onto the paint carrier 46 andcarried thereby. Thus, paint carrier 146 servesto deliver the paint to squeegee 43 andtin the operation .thereof its relationship to the `screen is Asuch that .a residual layerof paint will-remain'upon the screen for yiinelycover- :ing the openings of the pattern thereof, "which is desirable for the purpose-of having the succeeding printing -of maximum sharpness and definity. It should be noted that, iby its particular-means of suspension, paintfcarrier 46 is free iloating, in :that vit is transversely rockable about its point of attachment to rod 49, with guide rods '45 inhibiting swinging in a horizontal plane, whereby the bottom contacting -edge of paint carrier 4.6 is self-.adjusting with respect to the surface contour of screen 12 for the development .of reliable jpaint clearing action. Furthermore, wing members 47, 47 trap paint which might be inadvertently driven outwardly Itoward the sides of screen 12 and direct same inwardly for reception by carrier 46. Although paint carrier 46 may be fabricated `of any suitable, rigid material, the same lin the present .invention is made of metal 'to provide a conductive path therethrough lfor any static electric charges developed onscreen .12', whereby -such 'may be grounded on machine A. Heretofore, paint scraping or paint carrier members on printing machines have been designed solely for .fixed adjustment so that if the particular screen is not entirely with- Yin a single plane inadequate contact will be developed between such a paint carrier and the screen with resulting incomplete paint delivering operation. The paint carrier of the present invention is ysuspended such a manner as to assure positive contact with the screen surface despite any unevenness therein so that the .paint delivering operation will be at all times complete.

Speed reducer shaft 20 is provided at its lower end with a power take-E upon which is zatlxeda lower .crank arm 55, the latter being in planar parallel relationship to crank 19 and substantially axially perpendicular thereto, for reasons to be discussed below. Said lower crank 55 forms part of a system controlled by shaft 20 for -eecting the rocking of swing frame 10 which comprises a exible, connecting member 56, such as a chain or the like, secured at its rearward end to the outer end of crank 55 and engaged at its other or forward end to the upper end portion of a link 57 swingably mounted at its lower end upon a cross bar 58 between the lower ends of arms r8, 8.

An extension spring 59 engaged to .flexible member 56 and an element of the support structure 1 retains said member 56 against undesired displacement from its course of movement. Proximate its point of attachment to tlexible member 56, link 57 is pivotally engaged to the lower end of a companion link 60, cooperating therewith in toggle-joint-forming relationship, said companion link 60 being, in turn, swingably supported at its upper end to a bracket 61 xed on cross brace 3'. Link 57 is connected adjacent its upper end to one end of a spring 62 with which is associated, for adjustment purposes, 4a turnbuckle 63, the latter being connected by means of a chain 64 to a frame element at the upper forward portion of machine support. structure 1, whereby said springV 62 will bias link 57 into forwardly swungposition, in axially aligned-toggle-joint formation with companion link 60, all as may best be seen in fulllines in Figurev 1. With links 57, 60 in such aligned relationship a downward and rearward force will be thereby directed against crossbar 58, resulting in

arms

8, 8" being swung rearwardly at their lower ends and forwardly attheir upper ends to present'swing frame 10 in horizontal or full downward position, planar-wise parallel to bed 5. Thus, .in this relationship links 57, 60 cooperateto form a brace to prevent swinging ofl frame 10. Flexible member 56 is of such length that during swinging of lower crank l 5 through the forward half of its travel, that is, from the position thereof shown in Figure 2 to a position 180 therefrom, Valong the path indicated by the arrow, it will be in a slack, unstressed state, and, hence, exert no pull upon link 57 so that the toggle joint will be maintained through indiuence .of spring 62. However, upon movement of lower crankSS through the rearward half of its path of travel, tension will be developed in flexible member 56 resulting Ain, a 4rearward pulling force upon link 57, over- 'comingspring 62, and causing the breaking of the toggle -joint,-as links l57, 60 are swung `into the relationship shown in dotted .lines in Figure 1. By this action swing frame 10 will 1be swung downwardly at its rearward end, with arms 8, .8 being rocked upwardly and forwardly at their lowergends, lwhereby swing frame 10 is disposed in tilted 'or upward position, as vindicated in dotted lines in Figure 1. .It will -be observed that the center of .gravity of swing frame 10 is located rearwardly of its transverse median line due to the combined weights of motors 28, V29 land speed reducer 421. `A plurality of coil springs 65 are engaged .at their -forward ends to cross-bar 58 and at their rearward ends to members 4 of the machine support structure 1 for -balancing the swinging of said cross-bar 58, and

larms

8, 8 with swing frame 10.

`In view of the foregoing, the angular relationship between cranksr 1-9 and 55 will be understood to cause swing frame 10 to be in a-horizontal or downward position during rearward travel of cross-head 13 and to be in upwardly swung position during forward travel of crosshead 13.

If desired, a vacuum system, indicated broadly at B, may be 'provided with machine A for maintaining work pieces w V`against shifting upon bed 5 to assure proper .registration with screen 12; said system does not form a part of the present invention, being of generally accepted 'or conventional design.

The-operation of machine A will be apparent from the above: When swing frame 10y is in upwardly tilted ,position, screen 12 will, through gravity, be suspended therebelow with connecting chain b being of such length that squeegee 43 will be spaced from said screen 12 so that no inadvertent, premature contact may be made thereon while cross-head 13 is being moved forwardly. By its uniqelyl controlled means of suspension, as described kherein above, paint carrier 46 will maintain engagement upon the surface of screen 12 during forward travel of cross-head 13 (swing frame .10* being in upward position.) to assure effective and reliable advancing of the paint to the forward end of screen 12. Cross-head 13 is driven in .forward travel by motor 28. Upon the arrival of cross-head 13 at the forward end of swing frame 10 the latter will be, through operation of the described togglejoint system, in lowered or horizontal position with squeegee 43 being presented in contact with screen 12' for yeffecting the printing stroke during the rearward travel of'cross-head 13 (paint carrier 46 having been restored'toraised position); it being remembered that motor 29 controls, through the associated pulleys, the rate of movement of-cross-head 13 during its rearward travel. The operation of machine A is entirely automatic land. the customarily, factory-providedpower of volts is adequate therefor. With swing frame 10 in raised or upward position and screen frame 12 correspondingly raised, theV operatormay remove the printed work piece and insert a blank with the interval of time therefor being sutiicient due to the relatively slower rate of speed of cross-.headv 13 in traveling forwardly as motor 28 is then controlling.

Provided on-machine A is an auxiliary lever system by operation of which swing frame 10 may be held in upwardly swung position at the election of the operator, such as for'etfecting any repairs and the like, and the use of which system does not require discontinuance of operation of motors 28, 29. A foot lever 66 extends for- .wardly from the lower portion of the support structure is connected to the adjacent front support member 4 by a `ilexible connector or chain 68, the latter being of such length as to be in slack condition when said arm 67 is Vertically disposed. A chain or other exible linkage means 69 connects arm 67 to the lower end of an elongated dog 70 which proximate its lower end is mounted for swinging in a vertical plane, as at 71, upon the forward end of a support member 72 such as of anglel iron, extending forwardly from the rear of the support structure 1. Said dog 70 is in immediate juxtaposition to toggle links 57, 60 and is adapted upon rearward swinging of its upper end to engage on its rearward upper surface a pin 73 projecting laterally outwardly from the lower end of link 60 (see Figures 1 and 3). Due to the eccentric mounting of dog 70 on member 72 the same will be biased, through gravity, downwardly and forwardly in its upper end, and hence spacedly forwardly of pin 73 when links 57, 60 are in aligned, brace-forming relation. Upon depressionof foot lever 66, arm 67 will be rocked forwardly placing chain 69 under tension, and thereby causing the lower end of dog 76 to be rocked forwardly with the upper end thereof being swung rearwardly into abutting engagement with pin 73 and cammingly acting thereagainst to force link 60 into upwardly swung position, overcoming spring 62 and breaking the toggle joint to permit swinging of swing frame into its tilted position. Pressure may be maintained on foot lever 66 to retain swing frame 10 in such attitude to allow any minor repairs to the machine, readjustment of the work, etc. so that upon release of such pressure, links 57, 60 will be restored for operative control by spring 62 and flexible connecting member 56, as dog 70 will thereby be freed for downward swinging out of engagement with pin 73. If however, it is desired to maintain swing frame in upward position without the constant exercise of pressure on foot lever 66, the user will manually rock swing frame 10 upwardly at its forward end to thereby cause cross bar 58 to` be swung upwardly and forwardly, and then the user will rock lever 66 upwardly from depressed position to a point above horizontal whereby arm 67 will be rearwardly and downwardly swung, stressing chain 68 with such rockingof arm 67 causing the same, by gravity, to be urged downwardly. In this manner, arm 67 will be brought into engagement with the beveled end 74 of a cooperating detent member 7S rigid on cross bar 58 and extending forwardlythereof. Whereupon, the use will release manual v'support of swing frame 10 and hence allow the engagement between arm 67 and member 75 to eifect retention of swing frame '10 in upward position until such time as the footlever 66 may be returned downwardly to normal disposition.

Connecting rod 1S and crank 19 in their proximate end portions are each provided with a series of 'apertures 76,

77 respectively for selected mutual engagement as by a `suitable fastener, such as a shoulder bolt, or the like.

It will be noted that connecting rod 18 is in overlying relationship at its apertured end to the similarly perforated end of crank 19 so that by the predetermined alignment a range of adjustability in two distinct manners is provided.

The distance between the point of attachment of crank arm to shaft 20 and the opening through which the particular bolt extends, determines the extent of travel of the cross-head 13. In other words, said distance 'represents a radius twice the extent of which measures thetravel of cross-head 13. Accordingly, the connection of connecting rod 18 to crank arm 19 with respect to the aforesaid center of rotation will determine how far cross-head 13 travels. Hence, the openings 77 kare presented for providing adjustability in the extent of travel of crosshead 13. 'Ihe openings 76 in connecting rod 18 are provided for determining that portion of swing frame through Ywhich cross-head 13 will be moved reciprocally. Thus,

provide travel of cross-head 13 only in the forward por- `units of varying dimensions in an eective economic manner, obviating any unnecessary travel of cross-head 13 so that the printing operation is accomplished with maximum speed.

It is understood that changes and modifications in the formation, construction, arrangement, and combination of the several parts of the screen printing machine may be made and substituted for these herein shown and described without departing from the nature and principle of my invention.

Having thus described my invention, what l claim and desire to secure by Letters Patent is:

l. A screen printing machine comprising a support frame, a work-receiving member mounted on said support frame, an elongated frame rockably mounted on said support frame for movement Within av vertical plane and above said Work-receiving member between horizontal position and' upwardly swung position, a squeegee carrier mounted in said elongated frame and being adapted for reciprocal movement. therealong, and power means comprising dferential speed motor means for causing said squeegee-carrier to travel `more Vrapidly in one direction of travel than the other.

2. A'screen printing machine as described in claim 1 wherein said power means comprises first and second Vmotors, said rst motor being adapted to cause said squeegee-carrier to travel more rapidly than said second motor, a switch for operation of said first motor, and means for intermittently closing said switch.

3. A screen printing machine as described in claim l wherein said power means comprises a speed reducer having a main shaft, iirst and second motors, Asaid rst motor being adapted to cause said squeegee-carrier to travel more rapidly than said second motor, means operatively connecting said irst and second motors with the main shaft of said speed reducer, a switch for opera- 'Ition of said first motor, and a switch operating plate axis of said elongated frame, a crank arm iixed on said shaft for rotative movement in a plane parallel to the plane of said elongated frame, a connecting rod pivotally vengaged at its ends to said crank and squeegee-carrier for effecting reciprocal movement thereof on rotation of said crank arm, and power means for causing said squeegee carrier to travel more rapidly in one direction than the other.

5. A screen Vprinting machine as described in claim 4 wherein said power means comprises first and second motors drivingly connected to said main shaft, said rst motor being adapted to cause said squeegee-carrier to travel more rapidly than said second motor, switch means for operation of said first motor, and means associated with said crank for intermittentlyclosing said switch means.

6. A screen printing machine comprising a support frame, a work-receiving member mounted on said sup-,- port frame, an elongated frame swingablymounted on said support frame for movement within a vertical plane and above said work-receiving member between horizontal position and upwardly swung position, a squeegeecarrier mounted in said elongated frame for reciprocal traversing movement therealong, power means carried on said elongated frame for movement therewith and biasing said frame into upwardly swung position, and link means disposed below said support frame, a flexible member operatively connecting said link means to said power means whereby said link means effect rocking of said elongated frame intoy downwardly rocked or horizontal position during travel of said squeegee-carrier in one of its directions of movement.

7. A screen printing machine comprising a support frame, a work-receiving member mounted on said supportframe, an elongated frame swingably mounted on said support frame for movement within a vertical plane and above said work-receiving member between horizontal position and upwardly swung position, a squeegeeycarrier mounted in said elongated frame for reciprocal traversing'movement therealong, power means carried on said elongated frame and comprising a main shaft, means connecting -said squeegee-carrier to said main shaft for reciprocal travel responsive to rotation thereof, said power means biasing said frame into upwardly swung position, cooperating toggle links located below said support frame, flexible means operatively connecting said links to said main shaft for toggle-joint `formation and deformation responsive to rotation thereof, and Ymeans engaging one of said links to said elongated frame.

. 8. A `screen printing machine as described in claim 7 wherein acrank arm is .mounted on said main shaft, a

flexible member engages said crank arm with one of said links, and resilient .means anchored on said support frame urging Vsaid links :into toggle-joint formation.

9. A screen printing machine comprising a support frame, a work-receiving member mounted on said support frame, an elongated frame rockably mounted on said support frame for movement within a vertical plane and above said work-receiving member between horizontal position and upwardly swung position, a screen member pivotally mounted on said work-receiving member, means connecting said screen member with said elongated frame for movement therewith, a cross head adapted for reciprocal travel along said elongated frame, rockable mounting means carried on said cross head for :swingable vmovement -within a plane substantially perpendicular `to the plane of the elongated frame a paint carrier lsuspended from said rockable mounting means for reciprocal movement downward into contact with and upward away from said screen during travel of the paint carrier responsive to operation of said rockable mounting means, and means for elevating said paint carrier from contact with said screen during travel in the opposite direction.

10. A screen printing machine comprising a support frame, a work-receiving member mounted on said support frame, an elongated frame rockably mounted on said support frame for movement within a vertical plane and above said work-receiving member between horizontal position and upwardly swung position, a screen member pivotally mounted on said work-receiving member, means connecting said screen member with said elongated frame for movement therewith, a cross-head adapted for reciprocal travel along said elongated frame, rockable mounting means carried on said cross-head for swingable movement in a plane substantially normal to the plane of the elongated frame, a paint carrier suspended from said rockable mounting means for reciprocal movement downward into contact with, and upward away from said screen member responsive to operation of said rockable mounting means, and guide rods for directing said paint carrier duringits movement for presenting same lto the screen member at a predetermined angle.

11. A screen printing machine comprising a support frame, a work-receiving member mounted on said support frame, an elongated frame rockably mounted on said support frame for movement within a vertical plane and above said work-receiving member between horizontal position and upwardly swung position, a screen member pivotally mounted on said work-receiving member, means connecting said screen member with said elongated frame for movement therewith, a cross-head adapted for reciprocal travel along said elongated frame, latch means pivotally mounted on said cross-head for swingable movement in a plane substantially normal to the plane of the elongated frame, a paint carrier com prising a relatively thin plate suspended at a point substantially intermediate its length from said latch means for disposition below said cross-head and being thus freely tiltable about its point of suspension, guide rods mounted on the under surface of said cross-head for receiving'said paint carrier for restricting its path of movement toward and away from said screen member, and means for intermittently operating said latch means for releasing said paint carrier for downward movement toward the screen member.

12. A screen printing machine comprising a support frame, a work-receiving member mounted on said support frame, an elongated frame rockably mounted on said support lframe for movement within a vertical plane and above said work-receiving member between horizontal position and upwardly swung position, a screen member pivotally mounted on said work-receiving member, means connecting said screen member with said elongated frame Vfor movement therewith, power means including a main shaft carried on said elongated frame, a crank mounted on said Vmain shaft, a connecting rod engaged to said crank at one end, a cross-head mounted on said elongated frame yfor, reciprocal traversing movement therealong, said cross-head being engaged to the other vend of said connecting rod, latch means mounted on said cross-head for intermittent engagement by -said Connecting rod, a pantvcarrier suspended from said ,latch means for disposition beneath said cross-head, and for movement therewith, guide Arods mounted on said crosshead for directing movement of said vpaint carrier, said paint lcarrier Shaving ldownwardly and forwardly turned wing elements, and means for limiting upward movement of said ypaint carrier.

13. A screen printing machine las described in claim l2 wherein the paint carrier is constructed of electrically conductive material for conducting staticfcharges on 4said screen member. Y

14. A screen printing machine comprising a support frame, a work-receiving member mounted on said support frame, an elongated frame swingably mounted on said support frame for movement within a vertical plane and above said work-receiving member between horizontal position and upwardly swung position, a squeegeecarrier mounted in said elongated frame for reciprocal traversing movement therealong, power means carried on said elongated frame comprising a main shaft axially normal to the longitudinal axis of said elongated frame, an upper crank xed on said shaft, a connecting rod pivotally engaged at ends to said upper crank and squeegee carrier for effecting reciprocal movement thereof on rotation of said upper crank, a lower crank mounted on said main shaft, a exible member secured to said lower crank, cooperating links for toggle-joint formation operatively connected to said llexible member, and means connecting said links and said elongated frame so that when said links are in toggle-joint formation the elongated frame will be in upwardly swung position, said lower crank and upper crank being so axially related as to cause said squeegee carrier to move toward the forward end of said elongated frame while said toggle joint is formed.

15. In a screen printing machine, a support frame, having an upper horizontal portion, an elongated rectangular frame rockably mounted on the upper portion of said support frame for movement within a vertical plane toward and away from said upper portion thereof, the mounting means therefor comprising arms extending downwardly from opposite sides of said elongated frame, a shaft transversly mounted on the upper portion of said -support frame, said arms being xed on said shaft, said -a projection provided on one of said links within the path of swinging movement of said dog, and leveroperated means for eifecting swinging of said dog to `bring same into contact with the said projection to `thereby cause swinging of said cooperating links out of toggle-joint formation and thereby said elongated frame Ywill swing into upward position.

17. A screen printing machine comprising a support frame, a work-receiving member mounted on said support frame, an elongated frame swingably mounted on said support frame yfor movement within a vertical plane and above said work-receiving member between horizontal position and upwardly swung position, a squeegeecarrier mounted in said elongated frame for reciprocal traversing movement therealong, power means carried on said elongated frame for movement therewith comprising a main shaft axially normal to the longitudinal axis of said elongated frame, a crank xed on said shaft for rotative movement within a plane parallel to the plane of the elongated frame, a connecting rod pivotally engaged at ends to said crank and squeegee carrier for effecting reciprocal movement thereof on rotation of said crank, said crank and connecting rod each having a plurality of openings in their proximate end portions, and fastener means for extension through selected aligned openings of said crank and connecting rod for controlling the extent and location of travel of said squeegee carrier.

18. In a screen printing machine, a support frame having an upper horizontal portion, an elongated rectangular frame rockably mountedon the 'upper portion of said support frame for movement within a vertical plane toward and away from said upper portion thereof, the mounting means therefor comprising arms extending downwardly from opposite sides of said elongated frame, a shaft transversely mounted on the upper portion of said support frame, said arms being fixed on said shaft, said arms at their lower ends extending downwardly below the upper portion of said support frame, a cross-bar extending beneath the lower ends of said arms, cooperating toggle-links operatively connected to said cross-bar, means for urging said cooperating links into toggle-joint formation, a dog member mounted rockably on said support frame, and in juxtaposition to said cooperating links, a projection provided on one of said links within the path of swinging movement of said dog, and lever-operated means for effecting swinging of said dog to bring same into contact with the said projection to thereby'cause swinging of said cooperating links out of toggle-joint formation and thereby free said elongated frame for swinging into upward position.

19. In a screen printing machine comprising a support frame, a work-receiving member mounted on said support frame, an elongated frame swingably mounted on said support frame, an elongated frame swingably mounted on said support frame for movement within a vertical plane and above said work-receiving member between horizontal position and upwardly swung position, power means carried on said elongated frame and comprising a main shaft, said power means biasing said frame into upwardly swung position, a pair of cooperating toggle links, one of said links being engaged at one of its ends to the support surface, the other of said links being engaged at one of its ends for connection to the elongated frame, spring means biasing said linksvinto toggle-joint formation, a crank operated by the main shaft of said power means, and a flexible, elongated, member engaging said crank with one of said links for efecting deformation of the toggle joint during movement of the crank through a portion of its rotative path.

References Cited in the tile of this patent UNITED STATES PATENTS 538,663 Dick May 7, 1895 1,776,459 Tull et al Sept. 23, 1930 1,922,710 Owens Aug. l5, 1933 2,039,909 Kem et al. May 5, 1936 2,110,140 Klopfenstein Mar. 8, 1938 2,567,578 Ranger Sept. 1l, 1951 2,704,510 Walsh Mar. 22, 1955