US2369602A

US2369602A - Screen printing apparatus

Info

Publication number: US2369602A
Application number: US397597A
Authority: US
Inventors: Petty Wesley; Carl H Wiley
Original assignee: Individual
Current assignee: Individual
Priority date: 1941-06-11
Filing date: 1941-06-11
Publication date: 1945-02-13
Anticipated expiration: 1962-02-13

Description

Feb. 13, 1945. w. PETTY' ET AL 2,369,602

SCREEN PRINTING APPARATUS 1 Filed June 11, 1-941 3 Sheets-Sheefl 66 Jaw/Mary Weak [D6 if (Taff f '57 q Feb. 13, 1945. w, T- ET AL 2,369,692

SCREEN PRINTING APPARATUS Filed June 11, 1941 3 Sheets-Sheet 2 Feb. 13, 1945. PETTY ETAL 2,369,602

' SCREEN PRINTING APPARATUS Filed June 11, 1941 5 Sheets-Sheet 3 9/ I V fimjzifafa, Jflas 1 1 6 at Cb/Z W1? Z) mesa Feb, 13, 1945 Wesley Petty and Elfi Carl R. Wiley,

Application June 11, 1941, Serial No. 397,597 9 Claims. (CL 101-114) In screen printing, particularly in the printing of signs and the like, the general practice usually consists in preparing a stencil of the entire copy to be printed on a screen printing frame, with the copy corresponding in all respects to the sign which is to be printed. The printing frame is then placed over a printing base or blank workpiece and a rubber squeegee with quantity of paint thereon is drawn across the frame, the paint being forced through the screen at the stencilled portions of the printing frame and onto the printing base. A complete copy of the stencil may be thus quickly printed on the workpiece. This method of printingprovides for a rather economic and rapid production of signs in large quantities. However, for small quantity production where one or .but very few of the same lettered signs are needed, the signs can be more economically lettered by brush since it is evident that a special printing frame for each individual sign of a plurality of signs would be very costly By virtue of the wearing qualities of a screen printed sign, its use for printing only one or several signs is oftentimes highly desirable, as for instance in the making of road signs, but because of the prohibitive cost of screen printing signs in small quantities, its application for such purposes has been greatlyrestricted.

It is an object of this invention, therefore, to

provide an improved apparatus for screen print-' ing.

Another object of this invention is to provide an improved apparatus for screen printing individual prints each of which is different.

A further object of this invention is to provide an improved apparatus for screen printing in which the same screen printing frames are used in printing a' plurality of signs each of which is lettered differently.

Yet another object of this invention is to provide an improved apparatus for screen printing which is simple in design, rugged in construction. and easily. and quickly operated to print a plurality of-signs which may be similarly or differently lettered.

Still another object of this invention is to provide an improved apparatus for screen printing in which the same printing frames are used for printing a plurality of different signs the letterus ing on which is comprised of different type characters.

Yet a further object of this invention is to provide an improved apparatus for screen printing in which a screen frame having character design markings suitably arranged thereon may be used a plurality of times to produce prints of different kinds.

Another object of this invention is to provide a screen printing apparatus having means for keeping the printing base out of rubbing contact with the screen printing frame between successive printing operations on the printing base.

A further object of this invention is to provide a combination letter aligning and squeegee guiding unit which also functions to move the screen on the printing frame away from a freshly printed letter immediately on lifting of the squeegee therefrom.

A particular feature of this invention is found in the provision of a screen printing apparatus including a table having means for adjustably supporting a printing base and screen frame for relative movement thereon.

Another feature of this invention is found in the provision in a screen printing apparatus having a relativelymovable printing base and screen frame with rows of character markings positioned thereon, of means for defining the movement of the base relative to the screen plate so that the markings in each row of the frame are positioned for printing in a straight line across the printing base.

Yet another feature of this invention is found in the provision of lettered spacing blocks arranged in copy form and longitudinally centered relative to the printing base, and which in cooperation with aligning means provide for a proper positioning of the corresponding letters on the screen frame relative to the printing base.

A further feature of this invention is found in the provision of a screen printing apparatus having a longitudinally adjustable screen printing frame with spaced rows of letters thereon and a printing base which is adjustably movable transversely of the printing frame so that relative movement between the printing base and screen plate provides for the location of a selected letter on the screen at a proper position for printing on the base.

A still further feature of this invention is found in the provision of apparatus for screen printing having a table with longitudinally extending members for slidably supporting a screen printing frame and a rack at one side of the table for holding a plurality of frames in a superpoled spaced relation, with the rack being movable to selectively position a frame in an 8 8 8 8 P061- tion with the frame supporting members on the table so that the selected frame is moved into a supported position on the table concurrently with its removal from the rack.

Yet another feature of this inventionis found in the provision of an apparatus for screen printing including a work table having a paint pan supported thereon for movement longitudinally thereof which isadapted to hold the squeegeewhen it-is notin use, and which has means thereon for removing paint from the squeegee in excess of that required for a particular printing operation.

A further feature of this invention is the provision of a linearly slldable screen frame and adjustable means associated therewith for aligning said screen frame for true linear travel. I

Further objects, features and advantages of this invention will appear from the following description when taken in connection with the accompanying drawings in which:

the line 3-4 in Fig. 2;

Fig. 4 is a view illustrated similarly to Fig. '2 showing the parts thereof in changed positions;

Fig. 5 is a transverse sectional view of the table as seen along the line 5-5 in Fig. 4;

Fig. 6 is a fragmentary detail view partly in section showing the means for moving the print ing base transversely of the table;

Fig. 7 is a fragmentary perspective view of modified means for moving the printing base transversely of the table;

Fig. 8 is a fragmentary detail view taken along line 88 in Fig. 4 illustrating the function of the combination squeegee guiding and letter aligning means during a printing operation;

' assacoa stood that any number of rows may be used and may be positioned to a proper printing position 9 is a front'perspective view of the paint I pan showing the squeegee in a supported position and the means forremoving excess paint from the squeegee; v

Fig. 10 is a top perspective view of the combination letter aligning and squeegee guiding means; Fig. 11 is a fragmentary perspective view of a screen printing frame;

Fig. 12 is a side view of a printing screen showing the aligning screws therein;

Fig. 13 is a sectional view as seen along the line iii-i3 in Fig. 12; 1

Fig. 14 is a front perspective view of a rack for holding the screen printing frames; and

.Fig. 15 is a transverse sectionalview of the rack shown in Fig. 14.

The invention as illustrated includes a table having means thereon supporting a screen printing frame for longitudinal movement and a printing base for transverse movement thereof. A-

printing screen'isshown ashav'ing a. pair of spaced longitudinally extending rows of letters alphabetically arranged'but it is to be understretched transversely thereof.

also that characters or designs may be substituted for the letters of the alphabet. A plurality of printing screens carrying t e complete alphabet are carried in a superposed spaced relation ina rack located to one side of the table. Means are provided-on the rack for selectively positioning each of the printing frames in an engaging position with the frame supporting means onthe table so that a selected frame is moved into a supported position on the table concurrently with its removal from the rack. By virtue of the relative movement between the printing base and the screen frame supported on the table, each letter on the printing frame relative to the printing base. To facilitate straight-line printing, the transverse movement of the printing base is defined by coacting stop portions provided on a mounting member for the printing base and on the table, so that in each extreme position of movement of the base one of the rows of, letters on the printing screen is arranged in proper alignment with the letterhis line on the printing base. With the printing base in a position corresponding to a row of letters, the printing frame is moved longitudinally of the table until a selected letter is in a proper printing position. This printing position is determined by aligning the selected letter transversely of the table with a corresponding letter indicated on spacing blocks centered relative to the printing base and supported longitudinally of the table. The letters 'on the spacing blocks are arranged in copy form, so that the correct sequence of the letters to be printed is indicated concurrently with the spacing provisions for such letter. To eliminate any smearing of letters already printed, means are provided to separate' the screen from a freshly printed letter immediately on the removal of the squeegee from the'screen and also during the relative movement between the screen and the printing base in the positioning of a new letter which is to be printed.

With reference to the drawings the invention is shown in Figs. l-3 as including a table Ii having legs i6 with side frame members i! and top end members It. Each top member is has a pair of spaced upwardly projecting brackets is thereon for supporting angle members 2| extending longitudinally of the table, with a, leg or angle portion 22 on each member 2|.being longitudinally arranged and turned inwardly of the table. A screen printing frame 23 of rectangular shape (Figs. 2, l1, and 15) is provided with a groove 24 in each longitudinal side member 28 thereof for slidably receiving a corresponding leg 22 of the members 2i, whereby to support the screen for guiding movement longitudinally of the table II. From a consideration of Fig. 2, it is evident that the screen printing frame 23 is longitudinally movable entirely across the table I! and outwardly from each end thereof.

The screen printing frame 23 is constructed in a usual manner with a. silk cloth 21 (Fig. 8)

It is contemplated in the present invention that the cloth 21 have a pair of spaced longitudinally extending rows of letters 28 and 29 stenciled thereon with the letters preferably being arranged in an alphabetical order, the letters A to N being indicated. The letters in each rod 28 and 29 are spaced a similar distance apart with the spacing between the front edges of adjacent letters being indi.

cated by indications 3| provided .on the upper longitudinal side 26 as viewed in Fig. 2. In practice it has been found that where the frame of the printing screen 23 is formed of wood, the,

. screen frame 23, therefore, to a position where a considerable portion thereof is out of engagement with the guiding portions 22, the bowing in of the sides 26 permits the screen frame23 to .rock relative to the guiding portions 22. This rocking movement, of course, impairs the true guiding of the screen frame 23 in a straight line longitudinally of the. table l5. To substantially eliminate the sides 26 from bowing inwardly each is provided with a metal bracing member 32 (Figs. 11 and 15).

In some instances the frames 23 become misaligned during use, or the grooves 24 therein may become worn so as to vary in depth. It is apparent that these conditions would also impair a true travel of the screen frame in the guides 22. To assure a correct aligning of the frame and guides in these cases the bottom of each groove 24 is provided with spaced screws 25 (Figs. 12 and 13) which are adiustably threadable laterally of the frame. Thus the screws 25 may be selectively adjusted in a direction outwardly from the'groove 24 to completely eliminate any side play of the frame 23 between the guides 22 and to align the frame 23 for straight-line travel over all portions thereofin a direction longitudinally v of the table 15.

is positively defined by cooperating stop or abutment portions 43 and 44 (Figs. 3 and 5) on the table top portion 35 and mounting member 33, respectively. The stop portions 43 are provided with adjustable screw 46 to limit the transverse movement of the member 33 to correspond with the spacing between the bottoms of the lettered rows on a particular screen plate 23.

The mounting member 33 is moved to its defined positions by'means including a U-shaped bracket 45 (Figs. 5 and 6) which is supported from the member 33 and extends through the top 35 of the movable unit 36. A manipulating lever 41 of substantially right-angle shapehas one leg '48 thereof extending outwardly through the front of the table through openings 46 and 5i formed in a frame member 52 of the unit 36 and in the front table member, l1, re-

' spectively. The leg 48 of the lever 41 is pivotally The screen printing frame 23 is operatively associated with a mounting member 33 (Figs. 3

and 5) for supporting a printing base or flat workpiece 34 illustrated for the purpose of clarity in the disclosure as being of arrow form. The mounting member 33 is slidablysupported for movement transversely of the table 15 on the flat top 35 of a movable table unit 36 arranged betwen the table side members 11 and top mem bore 18 and which will be later fully described. This support of the mounting member 33 is accomplished in an obvious manner by coacting angle irons 31 and 38 (Fig. 3)- provided on the flat top 35 and the mounting member 33, respectively. It is evident, of course, that tracks and rollers or the like may be used in place of the

coacting members

31 and 38. member 33 is provided with transversely and longitudinally extending centering lines 33 and 4i, respectively, to facilitate the centering of the printing base or work blank 34 thereon. The longitudinal centering line 41 is used to indicate the bottom of the letters to be printed on the base 34 so that in the centering of the base 34 the lettering line 42 thereon is arranged in longitudinal alignment with the centering line 41. Thus in the printing of a letter in a row 28 or 23 of the printing screen 23, the mounting member 33 is transversely adjusted until the centering line 4i is in alignment with the bottom of a row of letters longitudinally of the table l5. This positioning of the member 33 is obtained by limiting its transverse movement to defined positions corresponding to an aligned po-' sition of the centering line 4| with the bottom of a lettered row 28 and 29. The overall transverse movement of the member 33 and hence of the printing base 34 is thus equal to the distance between the bottoms of the rows 28 and 28 and The mounting supported by means indicated generally as 53 and mounted on the frame member 52, the other leg 54 being extended between the legs of the U-shaped member. Thus as is clearly evident from Fig. 6, movement of the lever 41 to its full line position moves the mounting member 33 and in turn the printing base 34 in a direction toward the front of the table, while movement of the arm 41 to itsdotted hne position moves the base 34 toward the rear of the table. A selective positioning of the base 34 corresponding to a row of letters 28 or 28 on the screen printing frame 23 is thus easily obtained. With a relative movement of the printing bas 34 and of the printing screen 23 in directions substantially normal to each other, it is apparent that any letter on the screen 23 may be readily positioned in proper alignment with the lettering line 42 on the printing base. In order to proper- 1y space the letters to be printed along the line 42 means are provided including spacing blocks 56 and 51, the blocks 56 having letters indicated thereon and being of a width corresponding to the width of the letters on the screen printing frame 23. The blocks 51 are of a width corresponding to the distance between adjacent letters on the screen 23. Referring to Figs. 2 and 5 the

blocks

56 and 51 are seen to be of substantially T'-shape with the leg or trunk portions thereof being adapted to be received in a grooved supporting member 58 extending longitudinally of the table l5. The member 58 is removably supported at its ends'on the table top members i8 by pins 53 (Fig. l) on the member l8 which are inserted in corresponding cavities (not shown) formed in the member 58. Prior to the start of printing operations the lettered blocks 56 are arranged in copy form with the blocks 51 positioned between adjacent ones of the blocks 56. All of the blocks 55 and 51 are then longitudinally centered as a unit relative to the transverse centering line 38 on the mounting member 33. Since the base 34 is also centered longitudinally with respect to the transverse center line 38, a proper .the printing base 34, means are provided for positioning the screenplate 23 relative to the spacing blocks 56 which include a combination squeegee-guiding and letter-aligning unit 61 having spaced side members 62 and 63 (Fig. 10) positioned on opposite sides of the screen 23 and about the screen supporting members 2i. The member 82 has

angle members

64 and 66 at

opangle members

34 and 33 so that the combina-- 5 tion unit 3| is locked in sliding guidable engagement with the members 2|. The'angle member 34 has an indicating element 43 secured thereto in a position extending transversely of the table II, the element 33 having aligned pointers 33 and 1| at opposite ends thereof. The unit 3| and hence the element 33 is thus adiustably movable longitudinally of the table II with the pointers .33 and 1| cooperating to align aspacing block I. with a corresponding indication 3| screen printing frame 23.

In the operation of the present invention, let it be assumed that the word Anna" is to be printed on the printing base 34. The spacing blocks 33 necessary to spell out the word Anna are arranged in the supporting member 33 with a block 31 positioned between adjacent ones of the spacing blocks 33. All of the blocks are then centered or equally divided on opposite sides of the transverse centering line 33. With the printing base 34in a centered position on the mounting member 33 the letter "A" is ready to be printed. The lever 41 is manipulated to its dottedline position shown in Fig. 6 so that the center ing line 4| on the mounting member 33 and hence the lettering line 42 on the base 34 are in longitudinal alignment with the bottom of the letters in the row 23. The combination unit 3| is then adjustably moved on the supporting members 2| until the pointer 1| on the indicating on the element 68 is opposite the left edge 12, as viewed in Fig. 2, of the first spacing block 53 which has the letter A thereon. With the combination unit 3| in this position, the screen frame 23 is adjustably moved along the members 2| until the indication 3| corresponding to the letter "A" on the screen 23 is opposite the pointer 33. The letter A on the printing frame 23 is now in a position to be printed on the base 34. A squeegee 13 of the usual type, such as indicated in Fig. 9 and having a rubber wiper portion 14 for carrying the printing paint, is then drawn across the letter A, its movement across the letter being guided by the guiding edge-13 on the side portion 32 of the combination unit 8| as is clearly shown in Fig. 8.

aseaeos thereto formed with an angular portion 10 comprising a leg 13 which extends laterally inwardly of the pan with a second leg projecting upwardly therefrom. The leg 13' is provided with a vertically extending cavity or slot for receiving the rubber portion 14 of the squeegee 13. The slot 3! at its lower end has a recess 33 formed in one side thereof. Thus after the squeegee is dipped into the paint pan 4!, the rubber portion 14 is drawn through the slot 30 to wipe off all excess paint, it being obvious that only the paint which passes through the recess 33 will be retained on the squeegee portion 14. By virtue of the construction of the bracket 15 the excess paint drops directly into the pan 4!. It is contemplated that a bracket 33 having a particularly 7 the cloth 21 on the printing frame 23.

sired slot 30 and recess 43 be used for the printing of certain sized letters, so that substantially only that amount of paint is retained on the squeegee which will print one of such letters.

In screen printing the letters are heavily print-- ed so that they are not immediately dried. To prevent any smearing or'marrlng of a letter after it has been printed, such as might occur by a rubbing contact of the printed letter with the silk cloth 21 of the screen printing frame 23, means including the lower side portion 63 of the combination unit II are provided for immediately separating the cloth 21 away from a freshly printed letter. As previously mentioned the side portion 33 is positioned beneath the screen printing frame 23 so as to be extended transversely of the table I 3 and between the printing base 34 and The side portion 83 is laterally offset from the guiding edge 13 (Fig. 10) of the side portion 32 so that during the printing of a letter by the squeegee 13, and as is clearly apparent from/Fig. 8, the cloth 21 is depressed in a gradual curve over the side 33 whereby to prevent any shearing or cutting of To print the next letter N the lever 41 is moved to its full line position as shown in Fig. 8 so that the lettering line 42 on the printing base 34 is moved into longitudinal alignment with the bottom of the letters in the row 23 which includes the letter N. The guiding unit 8| is then moved along the members 2| until the pointer 1i on the indicating element 83 is opposite the left edge 12, as viewed in Fig. 4, of the second spacing block 53 which has the letter N" thereon. with the combination unit I in this position, the screen frame is moved along the members 2| until thepointer 33 is opposite the indication 3| corresponding to the letter N. The letter N'" is now ready to be printed, the relation of the apparatus parts for this printing operation being shown in Fig. 4. The remaining letters in the word "Anna are printed in a manner similar to that above described for the first two letters A" and "N" thereof.

In order to have the squeegee 13 readily available for all printing operations a paint pan 43 is provided with a portion 33 extending upwardly from one side 43' thereof having a laterally exthe cloth on such side. However, the side 83 is arranged suiliciently close to the letter being printed so that after the printing operation and immediately on lifting of the squeegee 13 from the cloth 21, the cloth 21 is raised by the side 63 away from the freshly printed letter. It is contemplated that the lower side of the member 63, as viewed in Fig. 8, be provided with slidable rings or collars 11 spaced thereon so that when the mounting member 33 is in one of its defined positions they will be positioned to the sides of the printed lettering on the printing base 34. A substantially point rather than a face contact is thus provided between the side member 33 and the printing base 34. To eliminate any rubbing contact of the prin ing screen 23 with the printing base 34 during the relative movement therebetween, means, including the movable table unit 38 previously mentioned, are provided for moving the printing base 34 laterally away from the screen plate 23 during such relative movement. Thus as is shown in Figs. 3 and 5, the

side members

52 and 3| which depend from the top portion 33 of the unit 33 are positioned inwardly of the table side members H, the top portion 35 extending between the table top members l3 and over the side member H. A foot treadle 42 is hinged at one end 33 to a porconnected at one of pressed position. namely,

hers 2| on the table It.

. aseaeca 4 is moved upwardly against the cloth 21 of the screen plate23 by means of tension springs 81 82 and at their opposite ends to the supporting legs l8 of the table It. It is evident. therefore, that the unit 38 is in a floating position between the side members l1 and top members 18 of the table I 5 with its upward movement in response to the action of the springs 81 being defined by engagement of the base 34 with the screen plate 23. and its movement in a, downwardly direction away from the screen plate 23 being defined by the engagement of the overlapping ends of the top portion 35 with the side members l1 of the table 15.

By virtue of this construction of the movable unit 38 and its assembly relation with the operatirg lever 41 and mounting member 33, the screen plate 23 and mounting member 33 are capable of being relatively moved to a predetermined printing position when the treadle 82 is in a dewhen the printing base 34 is separated from the printing screen 23'. All of the relative adjusting of the base 34 and screen printing frame 23 prior to the printing of a. letter may, therefore,'be entirely completed while the base 34 is in a position entirely removed from rubbing contact with the screen plate 23. After these adjustments are made the treadle portion 82 is released to permit the printing base 34 to -move into a position for printing by the screen plate 23. Since the treadle 82 is foot operated, its retention in a depressed position in no way interferes with the use of both hands of the operator in relatively setting the screen printing frame and the printing base.

In the description thus far, only one printing.

screen 23 having letters A- to N thereon has been described. In some instances, such as where the letter characters are rather small, a single screen may be used having all of the letters of the alphabet arranged thereon. However. the letters are usually sufflciently large to require more than one screen for a complete alphabet. To facilitate the use of a plurality of screens having the alphabet divided thereon, a cab net 88 for the screens is provided at One end of the table It (Figs. 1. 14 and The cabinet 88 includes a rack 88 constructed to hold the printing screens in a superposed spaced relation. Th rack s slidably supported between guiding members 8| for movement vertically of the ,cabinet 88 to selectively position a screen frame 23 at an opening 82 in the cabinet wall 88.

In the relative assembly of the cabinet 88" with the table iii, the opening 82 is arranged in' the wall 88 so .as to be in longitudinal and transverse alignment with the screen frame guiding mem Thus on positioning of a selected frame 23 at the opening 82, removal of such frame from the rack 88 through the opening 82 concurrentl engages an angle portion 22 of the members 2| in a corresponding recess 7 24 on the screen. A transfer of the screen printtherefore, simply accomplished in a single operation. It is readily apparent thatthe cabinet their ends to the foot treadle I the screen printing cabinet 88 and rack ing frames from the rack 88 to the table I! is,

in a vertical direction moves screen printing apparatus 'markings in a screen frame 88 may be located in close proximity to the table l5, since during the printing operation should the screen printing frame-23 extend outwardly from the end of the table, such extending end of the screen plate is positioned in the opening 82 and on the rack 88.

The proper positioning frame 28 at the opening 82 is accomplished by a manual operating lever 83' having one end extending outwardly from the cabinet 88 through the wall 81 and its opposite end 88' pivotally connected to a connecting portion 84 on the rack 88. The lever 88 is pivotally supported intermediate its ends as at 88 on a portion of the cabinet. A first class lever is thus provided so that pivotal movement of the lever end 85 the rack 88 a corresponding vertical distance. The cabinet wall 81 through which the lever 83 extends is formed with notches 88 for releasably catching the operating end 85 of the lever 83. Three of such notches are illustrated in Fig. 14', with a notch corresponding to one of the three screen printing plates 23 shown in Fig. 15. The movement of the rack 88 is facilited by the use of counterweights 98, it being apparent that tension springs or the like may be similarly used.

As shown in Fig. 14, the cabinet 88 may have of a screen printing supported thereon a cabinet IN having trays I82 therein for storing the spacing blocks 58 and 51. As previously mentioned, the supporting.

may be frequently printed in succession it is eviinconvenience might arise should frames 23 for both sized letters be held in the same rack 88. To overcome this inconvenience, a second cabinet and rack assembly 88'-88' similar in all respects to the 88 previously described, may be located on the other side of the table .15 (Fig. 1). As above described, the screen printing frames are table l5 from each end net 88, therefore, holding screen printing frames dent that some having letters thereon of one size, and the other cabinet 88' holding printing frames having letters thereon of another size, the frames may be interchangeably used on the table 15 with equal facility. It is, of course, obvious that two frames may be slidabl supported on the table ii at the same time so that screen printing frames having different sized letters thereon-may be alternately used in some instances without the necessity of their being moved from the table l5.

As was previously mentioned, the improved of this invention is readily adapted to operate with screen frames having any number of rows of markings thereon. Thus referring to Fig. 7, there is illustrated means for .moving the printing base 34 to three predetermined positions. corresponding to a row of (not shown), having three rows of markings thereon. The front side member l1 of the table I! is formed with an elongated opening 8| having three notches 5la Bic spaced longitudinally thereof. The manipufreely movable outwardly from the thereof. With the. cabilating lever 41 has the end as thereof enemy I engageable in a guide or swivel ring llll operatively supported from the U shaped member 4!. Thus with the lever and 48 in the center notch lib, the b'ase 34 is positioned so that the printing line 42 thereon is aligned longitudinally with the center row of markings on the three-row screen frame. With the lever end 4| in the notch lib. the base 34 is moved toward the rear of the table I! to align the center line 42 with the upper row of markings on the screen frame. when the lever end 48 is in notch Ha, the center line 42 on the printing base 34 is in longitudinal alignment with the lower row of markings. It

. is evident, therefore, that any number of notches such as IMP-Sic may be ,used depending upon the number'of rows of markings on the screen frame. the space between the notches being such that movement of the, lever end 40 from one notch to a next adjacent notch corresponds to a movement of the printing line 42 on the base 34 from a position in longitudinal alignment with the bottom of the markings in one row to a Desition in longitudinal alignment with the bottom of the markings in a next adjacent row.

The operation of the invention has been described-above with specific reference to the printing of lettered signs. However, it is notlimite'd in its operation to the printing of lettered signs alone, but may be used equally well for printing designs, numerals. or like character markings. Thus in design printing the component parts of the design are suitably arranged on the screen frame 23 and the printing b'ase 34 and frame 23 are relatively moved until each design part to be printed is in its proper printing position relative to the remainderof the bodyof the design. In

corresponding to the spacing of said characters. means supporting said blocks longitudinally of said table and in a centered relation longitudinally of said printing base, means aligning said spacing blocks in succession with certain of said characters-transversely of said table, and means supporting said aligning means for adjustable movement longitudinally of said table.

2. An apparatus for screen rinting on a printing member comprising a table, a screen printing drama having letters in a longitudinally spaced relation thereon, means supporting said printing frame for movement longitudinally of said table, means supporting said printing memtable.

3. An apparatus for screen printing on a flat workpiece with a squeegee comprising a table,

this manner, therefore, a complete design may be simply and quickly printed.

From a consideration of the above description and drawings. therefore, it is seen that the invention provides a screen printing apparatus which is very simple in construction and easily operated to print a plurality of like signs or signs having diil'erent words thereon. The apparatus is flexible in operation to the printing of signs having different sized character letters and provides for a multiple use of the screen printing frames so as to wDDrecia'bly reduce the cost for making individual signs by the screen printing process. Also the apparatusis readily applicable to screen print designs, character markings and the likepsince it is readily adapted for use with screen printing frames of any desired size having any number of rows of character markings arranged thereon.

Althou h this invention has been described with reference to a specific embodiment thereof, it is to be understood that it is not to be so limited, since alterations in the parts and their relative arrangement can be made which are within the full intended scone of the invention as defined by the appended claims.

We claim:

1. Apparatus for screen printing on a printing base comprising a table, a screen printin frame unit having characters spaced thereon. with the spacing of said characters being indicated on the frame of said unit. means sup ort- .in: said printing base on said table including a holding member, means centering said printin base on said holding member, means carried by said .table supporting said frame unit for slidable movement over said printing base means supporting said workpiece on said table, a screen printing frame having letters spaced thereon, means adiustably supporting said screen frame for movement longitudinally of said table and relative to said workpiece, a unit for guiding said squeegee across a letter to be printed on said workpiece including a pairof connected spaced side, members, means supporting said guiding unit for slidable movement longitudinally of said table with said side members extending transversely thereof, one of said side members being positioned over said screen frame and the other thereof between said workpiece and screen frame,

and means for aligning an edge of said one side member with the end of said letter to be printed so that said edge uides said squeegee across said letter, said other side being laterally offset from said one edge to permit all portions of the letter being printed to be flattened on said workpiece when the squeegee is passed thereover and to retain the screen frame away from the impression of said letter rinted on the workpiece after the squeegee has been lifted from said screen frame.

4. An apparatus for screen printing on a printing base comprising a table, means for supporting said printing base. on said table, a. screen printing frame having characters thereon, means supporting said screen frame for slidable movement across said printing base, means intermediate s aid-printing base and screen frame for retaining a spaced relation between certain opposite portions of said frame and-printing base, and means supporting said intermediate means for movement across said printing base, with movement of said intermediate means over a character impression freshly printed on a portion of said printing base preventing contact of said impression with the screen frame on move ment of the same to a new printing position.

and longitudinally of said table, spacing blocks 5. An apparatus for screen printing on a flat workpiece comprising-a, table, means supporting said workpiece on said table, a screen printing frame having letters spaced longitudinally thereof, means slidably supporting said screen frame for movement over said workpiece, means for successively spacing the letters to be printed across said workpiece including an aligning unit having a portion thereof intermediate said workpiece and screen printing frame, and means supporting said aligning unit for slidable movement over said workpiece, with movement of said aligning unit in the spacing of a letter to be printed in turn moving said intermediate portion over a letter just printed on the workpiece to prevent rubbing contact between such printed letter and the screen frame.

6. An apparatus for screen printing on a printing base with a squeegee comprising a table for supporting said printing base, a screen printing frame having characters thereon, means supporting said frame for movement over said printing base, a 'paint pan, means supporting said paint pan for movement over said printing base, and means on'said paint pan for removing paint from said squeegeein excess of that needed for printing one of the characters from said frame on said printing base.

7. An apparatus for screen printing on a printing base comprising a table for supporting said printing base, a screen printing frame having letters spaced longitudinally thereof, means supporting said screen frame for adjustable movement across said printing base, spacing blocks corresponding in size to the letters on said screen frame and having letter markings thereon corresponding to such letters, a member extending longitudinally of said table for supporting said spacing blocks, means for centering said spacing V ably receive the same.

blocks longitudinally of said printing base, with the letters on said blocks being arranged in copy form to correspond with the letter arrangement to be printed on said printing base, and means successively aligning said blocks transversely of said table with the letters on said frame corresponding to the letters marked on said spacing blocks.

- 8. An apparatus for screen printing on a printing base comprising a table for supporting said printing base, a screen printing frame, means including spaced guide ways slidably supporting said printing frame for movement over said printing base, said printing frame having grooves therein corresponding to said guide ways and adapted to, guidably receive the same, and align ing means engageable with said guide ways. spaced in each of said grooves and adjustably supported on said frame, said aligning means being adjustable to provide for the linear movehient of said frame over said printing base. v

9. An apparatus for screen printing on a printing base comprising a table for supporting said printing base, a screen printing frame, and means including spaced guide ways slidably supporting said printing frame for substantially linear movement over said printing base, said printing frame having grooves therein corresponding to said guide ways and adapted to guid WESLEY PET'I'Y. CARL H. WILEY.