US1892267A - Stencil brush - Google Patents

Description

STENC IL BRUSH.

Grginal Filed Deo. 13. 1930 2 Sheets-Sheet @sa 279 i932, J. FLQCKHART STENC IL BRUSH Original Filed Deo. 13, 1930 2 Sheets-Sheet INVENTOR; JAMES FLOCKHART ATTORNEY.

Patented Dec. 27, 1932 liiatTED STATES PATENT OFFICE s'rENoIL BRUSH Application led December 13, 1930, Serial No. 502,112. Renewed Hay 24, 1932.

riihis invention relates to improvements in stencil brushes and more particularly to ink spreaders for screen stencil machines.

Among the objects of the invention are to accomplish uniform feeding distribution and penetration of the ink or color substances through the stencil.

Other objects are to provide an ink fountain and spreader that is automatic in action 0 and which may be synchronized "with the other functions of screen printing machines actuated by power.

A further object is to accomplish a double spreading action with each inking operation of the brush.

Other objects and advantageswill appear as the description progresses.

Reference is here made to my copending applications as follows, for further particulars: Fountain brush, Ser. No. 396,082, filed Sept. 30. 1929, stencil printing machine, Ser. No. 429,337. tiled Feb. 18, 1930, and applications to be filed contemporaneously with this application, entitled Stencil brushes and screen printing machines.

In this specification and the accompanying drawings the invention is disclosed in its preferred form'. But it is to be understood that it is not limited to this'form because it may be embodied in other forms. i It is also to be understood that in and by the claims following the description it is desired t0 cover the invention in whatsoever form it may be embodied.

ative mechanisms.

Fig. 2 is aplan view from above, of the same.

Fig. 3 is a vertical section of the stencil brush taken on the line IlI-i-III, Fig. 1, shown in the operative position on the inking and spreading stroke. I

Fig. 4 is a similar view shown in the return stroke with the fountain closed and the second spreader in operation.`

Fig. 5 is a full side elevation of the same, as shown in Figs. 1-2.

In detail the construction illustrated in the drawings, referring to Figs. 1-2 comprises the sides 1 and 2 of the swing frame prlntlng machine. The reciprocating crosshead a is guided in slots in these Sides and 5' is adapted to pass back and forth above the screen stencil 4, stretched taut on the screen frame 5.I The screen frame is adjustably held in the swing frame 1-2, by the screws 6.

The crosshead has the slotted brackets 7-7 thereon which engage the transverse push rod 8, which synchronizes the movement of the crosshead with the rise and fall of the swing frame 1 2.

The pivot rod 9 is mounted in the brackets 65 10-10, also fixed on the crosshead 3. The rod 9 moves in unison with the crosshead 3; whereas the push rod 8 stops and starts in synchronism with the frame 12, because of the'E slots 7 in the brackets 7 7, as will 7o be hereinafter more fully described.

Referring to Fig. 5, the ink fountain brush consists of the front plate 11-11 having the ends 12-12. The upper portions of the ends 12-12 are pivoted on the 75 rod 9. These ends 12 are also provided with the hooks 13-13 engaging the push rod 8. The rear plate 14 fits slidably between the ends 12.-12, but snugly enough to confine the ink X within the cup formed by the curved plate 11. This plate 14 has the lugs 15-15 pivoted on the rod 9. In the closed position, shown in Fig. 4, the plate 14 abuts the crosshead 3.

The lower edges of the plates 11-14 contact in the closed position to form a gate at 16, between the spreaders 1'Z-18, respectively fixed in the lower edgesA of the plates 11-14. These spreaders or brushes are pref 90 erably set at an angle of approximately 60 to the plane of the screen 4. This angle is about the angle best adapted to the spreading of heavy inks and enamels such as are used in this art. I have discovered that heavy pressure and squeegee-like action is not desirable in attaining the highest development of screen stencil impressions. A single piece of heavy soft leather. beveled as shown, or several thicknesses of thin leather in lamithe screen stencil.

' brackets 10--10. Y

nated formation, have proved the best material for the spreaders.

i Normally the swing frame 1-2 is elevatn ed on its pivot, not shown, with the fountain brush in the closed position, as in Fig. 4, due to the pull of the rod 8. Upon the lirst phase of the operation of the machine` the rod 8 is pushed forward as is showil in Fig. 3. As the rod 8 has a free engagement with the crosshead 3 due to the slots 7', the body 11-12 of the brush is swung on the pivot 9 to open the fountain at 16, see Fig. 3. The brackets 7-7 are then engaged by the movement of the rod 8 and the frame 1-2 is low-V ered. The continuation of the stroke spreads the ink X across the screen 4, ahead of the spreader 18, which distributes it evenly, and brushes or rubs it gently through the screen stencil.

The initial portion of the return stroke, Fig. 4, causes the rod 8 to pull on the hooks 13-13, to close the gate 16. which pushes the plate 14 against the crosshead 3 and rotates the ink assembly on the rod 9. This elevates the spreader 18, and brings the spreader 17 into operative position on the screen 4. The continued pull of the rod 8 causes it to engage the brackets 7'-7. and return the inking mechanism to the starting position. During the return stroke the spreader 17 forces the surplus ink X through The end of the stroke of the rod 8 again pulls the swing frame 1-2 into the elevated position with the ink gate 16 closed, during the operation of removingr andreplacing the impression sheet beneath e th'e stencil.

The operation has been described as in a power operated machine. Itis obvious, how ever, that the crosshead 3 may be operated by `manually pushing and pulling the rod 8, or otherwise applying movement to the plate 11. The friction of the spreader 18 on the screen 4 causes it to lag while the plate 11 moves away from -it to open the gate 16.

The quantity of ink fed is regulated by means of the screw 19, threaded in the plate 11 and engaging the plate 14. This screw 19 may be set up to entirely7 close the gate 16, while the fountain brush is being installed or removed from the machine. which is readf ily done by releasing the setscrews 21)-20 and Ql-Ql to release the rod 9 from the When not in use the brush will stand upright on the spreaders 17-18.

To insure the operation of the rod 8 in the slots 7 7. as described. it is desirable to apply a definite frictional resistance in the operation of the crosshead 3. This is simply accomplished by splitting the crosshead guides 3-3 and screws 21-21. see Fig. 5. so that they are frictionallv retarded in their respective grooves S22-22 in the sides 1-2.

The transverse slits S23-23 extending upsnreading them byy the ward into the body of the spreaders l7-18, see Figs. 1-2, render them more adaptable to inequalities in the plane of the material upon which the stencil impression is being made. These slits are made in laterally od'- set or break joint relation in the respective sprcaders, so that any ink leaking through one spreader will be distributed by the tollowing spreader.

Thus slitting the spreaders is especially advantageous in making stencil impressions upon leather and other uneven surfaces and in compensating for uneven adjustments of the screen frame with respect to the platen with which the screen 4 cooperates. These slits in eli'ect create a plurality7 of longitudinally alined spreaders, whether used singly or in pairs, as shown.

Havingr thus described this invention, what I claim and desire to secure by Letters Patent is:

1. A stencil brush including a front plate having enclosing ends; a rear plate pivoted between said ends and meeting the lower end of said front plate to form an ink fountain; spreaders in the lower edges of each of said plates respectively.

2. A stencil brush including a front plate having enclosing ends; a rear plate pivoted between said ends, the lower edges of said plates meeting at an angle to each other; spreaders in the lower edges of each of said plates respectively, on opposite sides of said meeting edges.

3. A stencil brush including a pair of divergi'ng plates pivoted together and meeting near their lower edges and adapted to form an ink fountain; and spreaders fixed in the lower edges of said plates, at an angle to the perpendicular, adjacent said meeting edges.

4. A stencil brush including a pair of diverging plates pivoted together and meeting near their lower edges and adapted to form an ink fountain; supporting means engaging said pivot; means for moving said plates relatively to each other; and spreaders at the lower end of both of said plates.

5. A stencil brush including a pivot rod guided in a frame; a pair of plates pivoted on said rod and adapted to form an ink fountain; preaders lixed in the lower edges of said plates; and means for moving said pivot rod back and forth and moving said plates relative to each other.

6. A stencil brush including a reciprocat ing mechanism having a pivot rod thereon; an actuating mechanism having a delayed engagement with said reciprocating mechanism; a. pair of plates pivoted on said pivot rod and meeting near their lower edges and adapted to form an ink fountain, one of said plates engaging said actuating mechanism; and spreaders fixed in said plates respectively, on opposite sides of said meeting edges.

7. A stencil brush including a front plate having enclosing ends; a rear plate pivoted between said ends and meeting the lower end of said front plaie to form an ink fountain;

spreaders having: transverse splits therein, in

the lower edges of each of said plates, respectively. I

In testimony whereof I have hereunto set my hand this 5th day of December, 1930.

JAMES FLGCKHART.

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