US2581775A

US2581775A - Screen printing machine

Info

Publication number: US2581775A
Application number: US47878A
Authority: US
Inventors: Louis R Wade
Original assignee: Individual
Current assignee: Individual
Priority date: 1948-09-04
Filing date: 1948-09-04
Publication date: 1952-01-08
Anticipated expiration: 1969-01-08

Description

Jan. 8, 1952 R. WADE 2,581,775

SCREEN PRINTING MACHINE Filed Sept. 4, 1948 2 SHEETSSHEET l INVENTOR.

Jan. 8, 1952 Filed Sept. 4. 1948 L;F1 VVAIDE SCREEN PRINTING MACHINE 2 SHEETSSHEET 2 HVVENTUR.

H ii;

Patented Jan. 8, 1952 UNITED STATES PATENT OFFICE SCREEN. PRINTING. MAGHIN E Louis B. Wade, Los Angeles, Calif.

.-Application September 4, 1948, Serial No. 47,878

4 Claims.

.Myirivention relates to screen .printmg...machines and includedin .theobiects, of .my invenonare:

First to provide a screen printing machine whichincorporates a :novel squeegee operating mechanism, having a readily adjustable stroke so. that. printing screens. of. different areas may be, interchangeably .used in the machine;

gsecond, to .providea screen printing machine wherein the,printingscreenisraised and lowered automatically. intime'drelation to themovement of; thesqueegee, the .return movement of the squeegee occurring .while the printing screen is raised -so that duringv such time. work may be changed;

.Third, to providea screen .printing machine in which the printing screen, carrier, and the squeegeetoperating.mechanism share a common pivotal axis so that tilting .movement. of ,the

carriage does notafi'ect operation of the squeegee operating mechanism; and

Fourth, .to.provide a screen printing machine which, althoughautomatic in its operation except for insertionand removalof-the work, is

particularly simpleiof construction-and dependable. in its operation.

With the v above and other objects in -viewas may. appear hereinafter reference-isdirected to the accompanying drawings in which .Eigure .1 isasubstantially diagrammatical side view of-my .screen printingmachine showin it in. aposition assumed when the printing screen israised; I

Figure 2 is. afrontview of .the .machine taken from the planet-2 ofFigure l;

:Eigure 3; is a fragmentary -.substantiall-y diagrammaticalqview showing .my screen printing machine inra position assumed when :thescreen is contact-with the table;

Figure-4-is a fragmentary-view of'the squeegee carriage mechanism shown during the return movement of the squeegee;

Figure 5 -is a similar view showing. the squeegee duringits operatingmovement: and;

Figure disasubstantially diagrammatical view taken' throug-h' 6.-6- of Figure 1 and illustrating thedrivemeans for the-soreenrprinting machine.

Myscreen printing machine includes a frame structure l of generally rectangular form which extends under and'wsupports a table! by means of adjusta-ble posts 3. The'tableis-provided with suitable means. (not shown) for holding work in position for printing. The rear portion. of the frame -str'ucture I. includes an A frame 4-which journals-a transversely extended .main shaft: '5.

A pivotal frame structure '01- carrier 6 is mountedon the'main shaft .5'and extends forwardlyover the'tablei. Thecarrier ii'supports ascreen printing frame 1' which may be con-.- ventional. -Such screen printing frame involves a -wooden inner framecovered by a silk screen on. which-isformed the'design to be printedby rendering-certain .portionsof this screen permeable-to ink. The inner frame is adjustably mounted inv an outer frame for purposes of registering the design. The structure is notshown in detail inasmuch as the construction of such screen printing frames is well known.

The carrier" 6' also extends rearwardly from-the main-shaft 5 and is provided with a depending bracketewhich carriesa cam follower 9 adapted for-engagement with acam'track II). The cam track may be formed in theside of a main drive gear H. The drive, gear ii is engaged by a pinion gear l:2"dri-ven directly by a motor l3 or suitable speed reducing means. A conventional clutch I4 --is interposed with such clutch being operated' bymeans (not shown) fromthefront of the machine; While the cam and gear .ar rangement is shown for simplicity.of'illustration, it should be borne in mind that various link and lever arrangements may be employed to effect oscillation of 'the frame structure or carrierii'.

JOLlIIlQlGd-Oll'thii main shaft 5: is one or more squeegee operating levers l5. Each squeegee operating lever includes a radial portion I6 and anarcuate portion H. The center of the arcuate portion substantially coincides with the forward margin of the printing screen when the parts of the printing machine are inthe position shown in Figure 3. The arcuate portions of the levers iiare provided with adjustable clamps it which arepivota'lly connected tostruts' IS, the forward ends of which are joined to a squeegee carriage 20 adapted to travelxback and forth across the screen printing frame. It will thus be seen by examination of FigureB that irrespective of the adjustment of the clamps N3 the forward position of the carriage is-notzaltered. As shown in Figure 1, however, the rearposition of the carriageis altered by adjustment of the clamps-l8. By' this means the length of stroke may be changed as desired.

The squeegee carriage .22 may be conventional and is illustrated hereinsubstantially diagrammatical; The carriage actuates a squeegee. 2!

the form Ofht bar having a flexible wiping blade adapted to -,engage a printing screen. for the .ipunposeoh forcing ink through thepermeable portions thereof. It is desirable that a type of squeegee structure be employed wherein the ink is carried to the forward side of the printing frame without contact with the printing screen inasmuch as the printing screen is raised from the work during this movement. This may be accomplished by the use of an ink retainer blade 22 which is positioned for engagement by the squeegee to form a trough and by pivotally mounting the squeegee so that normally it is urged against the blade 22 by springs 23 but is drawn away from the plate when moved across the printing screen. In addition, elevating means 24 cause the carriage to raise when moved in a direction shown in Figure 4 and to lower when the carriage is moved in a direction shown in Figure 5.

The squeegee operating levers [5 are connected by lever arms 25 to links 26 which, in turn, are joined to levers 21 mounted on the shaft which carries the cam Ill and the gear I I.

Operation of my screen printing machine is as follows: The shape of the cam track l and the position of the levers 25 and 21 as well as the squeegee operating levers l are such that the screen printing frame occupies a lower position, such as is shown in Figure 3, for a predetermined portion of the cycle and a raised position, such as is shown in Figure 1, during another selected portionof the cycle. printing screen is in its lower position as shown in Figure 3 the squeegee is caused to move from the forward toward the rearward side of the screen by rearward pivotal movement of the operating levers l5 about the axis of the main shaft 5. When this stroke is completed the printing screen is raised. During this upward movement or immediately thereafter the squeegee is moved to its forward position at the same time the operator removes the printed material and places new work on the table. By the time the printing screen is ready to be lowered or during the lowering of the screen the squeegee reaches the forward side thereof ready for a working stroke.

It will be observed that a particularly simple operating mechanism is provided and that the desired action of the squeegee carriage is accomplished by reason of the fact that both the operating levers l5 and the frame structure 6 pivot about the same axis, namely, the axis of the main shaft 5. It will also be observed that adjustment of the operating stroke of the squeegee carriage is extremely simple, this being accomplished merely by adjustment of the clamps l8, preferably when the machine is in the position shown in Figure 3.

Having fully described my invention, it is to be understood that I do not wish to be limited to the details herein set forth, but my invention is of the full scope of the appended claims.

I claim:

1. A screen printing machine, comprising: a frame structure; a Work supporting means thereon; a main shaft supported by said frame structure; a carrier adapted to receive a printing screen and oscillatably mounted on said main shaft above said frame structure .to move said printing screen between lower printing position and a raised position relative to work on said supporting means; a squeegee carriage movable on said carrier over said printing screen; operating means for said carriage including a lever pivoted on the axis of said main shaft, and struts extending from said lever to said carriage; and

During the time that the means for actuating said carrier and said carriage in unison whereby an operating stroke of said carriage occurs when said printing screen is in engagement with said work and a return movement occurs when said printing screen is raised from said work.

2. A screen printing machine, comprising: a frame structure, including a work supporting means at the forward portion of said frame structure and a main journal means rearwardly of said work supporting means; a printing screen carrier pivotally mounted on said main journal means and adapted to move a printing screen between a lower printing position and a raised position; a squeegee carriage mounted on said carrier for forward and rearward movement across said printing screen, said squeegee carriage including a squeegee element, means coacting with said squeegee element to support a quantity of ink, and means for causing said squeegee to contact said printing screen and operate thereon during movement in one direction and to raise from said screen during movement in the opposite direction; nd a drive means for said carriage including a lever pivotally mounted on the axis of said main journal means and having an arcuate arm and a strut extending therefrom to said carriage,,said strut adjustable on said arm to vary the stroke of said carriage, the locus of said arcuate arm being in approximate coincidence with the forward edge of said printing screen when said screen is in its operating position and said carriage is in its tion and a raised position relative to work on said supporting means; a squeegee carriage movable over said screen between a forward and a rearward position; an operating means for said carriage, including a lever pivoted on the axis of said main shaft, said lever having an upright portion, the extremities of which are substantially equidistant from the forward margin of said printing screen when said screen is in its lower or printing position, and struts adjustable on said upright portion and extending to said forward margin for attachment to said carriage; and coordinated actuating means for said carrier and said operating means to cause rearward movement of said carriage when said printing screen is in its lower or printing position, and to return said carriage when said printing screen is in its raised position.

4. A screen printing machine, comprising: a frame structure, including a work supporting means at the forward portion of said frame structure and a main journal means rearwardly of said work supporting means; a printing screen carrier pivotally mounted on said main journal means and adapted to move a printing screen between a lower printing position and araised position; a squeegee carriage mounted on said carrier for forward and rearward movement across said printing screenysaid squeegee carriage including a squeegee element, means co- 7 acting-with said squeegee element to support a the opposite direction; and a drive means for 5 said carriage including a lever pivotally mounted on the axis of said main journal means and having an upright arm and a strut extending therefrom to said carriage, said strut adjustable on said arm to vary the stroke of said carriage, at in extreme points of adjustment said strut being approximately equidistant from the forward edge of said printing screen when said screen is in its operating position and said carriage is in its 6 forward position whereby regardless of the point of connection of said strut with said upright arm, the forward position of said carriage remains substantially unchanged.

LOUIS R. WADE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS