Multicolor Stamp

Abstract

A stamp for making multicolor prints comprises a downwardly open housing in which two superposed square blocks are vertically reciprocable, each block being independently rotatable about a horizontal axis. The upper block, held in a yoke at the lower end of a manually depressible plunger, carries differently colored ink pads on its four faces; the sides of the lower block are typefaces representing differently colored components of a composite design to be printed on a substrate. Depression of the plunger brings the top typeface of the lower block into contact with the ink pad on the bottom face of the upper block whereupon both blocks can be jointly moved down against a spring force to thrust the previously inked bottom typeface against the substrate. Upon the subsequent ascending stroke, the two blocks are separated and rotated codirectionally by one-way rack-and-pinion drives to confront the next typeface with the next ink pad.

Description

1. Field of the Invention

My present invention relates to a stamp for printing multicolor designs on a sheet of paper or any other substrate.

2. Background of the Invention

To print a multicolor design, its differently colored components must be separately stamped from complementarily shaped cuts or typefaces which are inked with their respective colors just before the stamping and which must be precisely aligned with the sheet so that the marks made by them should have the desired relative orientation.

3. Objects of the Invention

The general object of my invention is to provide a device of simple construction which satisfies the requirement for accurate alignment of successive stampings while being capable of handling three, four or even more color components of a design.

A more particular object is to provide means in such a device for automatically inking each of several typefaces with its assigned color between successive strokes of a plunger or other actuator successively bringing these typefaces into contact with the substrate.

4. Summary of the Invention

I realize these objects, in accordance with the present invention, by the provision of a downwardly open housing in which an upper block and a lower block are vertically slidable and mounted for independent rotation about respective horizontal axes, the two blocks being of prismatic shape and preferably of square cross-section. The sides of the upper block carry differently colored ink pads whereas the sides of the lower block form typefaces which constitute mutually complementary components of a design to be printed on an underlying substrate; each typeface, or cut, may comprise one or more characters (or portions thereof) or other parts of a composite logo or design. The blocks are spring-urged into an elevated position in which they are spaced apart, with the topmost typeface on the lower block confronting the bottommost ink pad on the upper block. Upon the depression of an actuator coupled with the upper block, this ink pad contacts the confronting typeface whereupon the two blocks descend jointly until the previously inked bottommost typeface contacts the substrate. Upon the subsequent ascent, the blocks are rotated by one-way drive means (such as a rack-and-pinion drive in combination with a pawl-and-ratchet coupling) to confront another typeface with another ink pad in preparation for the next printing stroke.

5. Brief Description of the Drawing

The above and other features of my invention will now be described in detail with reference to the accompanying drawing in which:

FIG. 1 is a perspective view of a stamp embodying my invention;

FIG. 2 is an elevational detail view; and

FIGS. 3A - 3E are somewhat diagrammatic elevational views of the stamp in five consecutive operating positions.

6. Specific Description

The stamp shown in the drawing, generally designated 10, comprises a downwardly open housing 11 of transparent plastic material within which are mounted two square blocks 12 and 13. Each block has a pair of gudgeons 14 and 14', centered on its horizontal axis, which protrude to permit vertical sliding movement of each block within lateral guide grooves 15 and 15' located on opposite sides of housing 11.

The upper block 12 is retained in housing 11 by a yoke 16 to which is attached a plunger 17 centrally fastened to the bight of the yoke and projecting upwardly beyond housing 11 through a collar 26 rigid with the top thereof. A spring 18 is coiled about the shaft of the plunger 17 and extends between collar 26 and the plunger head. Spring 18, when extended, retains upper block 12, yoke 16 and plunger 17 in their elevated or normal position.

The lower block 13 is retained in its elevated or normal position by a pair of curved leaf springs 21 located on each side of and within housing 11. The leaf springs of each pair are fastened at their lower ends to a boss 27 on the housing bottom and at their tops to opposite sides of a disk 28 mounted freely on the respective gudgeon 14'.

Block 12 carries a differently colored ink pad on each of its four faces 19a, 19b, 19c and 19d. A door 20, hinged at the top to housing 11, gives access to these pads for the purpose of reinking.

The four sides of block 13 carry different and mutually complementary typefaces 30a, 30b, 30c and 30d. Each typeface corresponds to a separate color imprinting to be made upon an underlying sheet of paper 29.

The two blocks 12 and 13 are unidirectionally rotatable about their horizontal axes by means of identical stepping mechanisms comprising respective racks 22, 22' on the inner housing wall and pinions 23, 23' idling on gudgeons 14, 14'. As particularly illustrated in FIG. 2 for the stepping mechanism associated with the upper block 12, a ratchet 25 rigidly secured to gudgeon 14 adjoins the pinion 23 and coacts with two spring-loaded pawls 24 pivoted to this pinion at diametrically opposite locations. During a descent of block 12, when pinion 23 rotates clockwise, the pawls are ineffectual so that the ratchet and the block are decoupled from the pinion. During the subsequent upstroke, with pinion 23 rotating counterclockwise, pawls 24a and 24b engage in the notches of ratchet 25 and entrain it in the same direction through 90.degree.. A similar action occurs with the stepping mechansim of block 13 which descends along with block 12 after a certain delay due to the initial separation of the blocks as determined by the upper limits of the lower guide slots 15'. The aforedescribed stepping mechanisms may be duplicated on the opposite housing side.

I shall now describe the operation of stamp 10 with reference to FIGS. 3A - 3E. In the manually depressed or lowered position of plunger 17 as shown in FIG. 3A, the bottom ink pad 19a of block 12 is in contact with the top typeface 30a of block 13 to ink the latter while the bottom typeface 30a makes contact with the underlying paper 29. When pressure on plunger 17 is released, as shown in FIG. 3B, springs 18 and 21 elevate the blocks 12 and 13 until their pinions 23 and 23' re-engage the respective racks 22, 22'. With spring 18 stronger than springs 21, the upper block 12 rises more quickly and separates from the lower block 13 whereby both blocks can execute their codirectional (i.e., counterclockwise) rotation through 90.degree., as shown in FIG. 3C, preparatorily to the next downstroke in which typeface 30b contacts the pad 19b (FIG. 3D) while typeface 30d is bottommost to print on the sheet 29 (FIG. 3E). Thus, all four sides of each block come into play upon as many consecutive reciprocations of plunger 17 and its associated stepping mechanism.

Claims

I claim:

1. A stamp for printing multicolor designs, comprising:

a downwardly open housing;

an upper block and a lower block vertically slidable in said housing and mounted for independent rotation about respective horizontal axes, said upper block being a prism whose sides are provided with differently colored ink pads, said lower block being a prism whose sides form typefaces constituting mutually complementary components of a design to be printed on an underlying substrate;

spring means on said housing normally maintaining said blocks in an elevated spaced-apart position;

actuating means on said housing coupled with said upper block for depressing same into contact with said lower block and thereupon jointly depressing both blocks against the force of said spring means whereby an upper typeface on said lower block contacts an ink pad on a lower typeface on said upper block while a lower typeface on said lower block contacts the underlying substrate; and

one-way drive means on said housing effective upon release of said actuating means and upward movement of said blocks by said spring means to rotate each block about its axis for confronting another typeface with another ink pad.

2. A stamp as defined in claim 1 wherein said blocks are of square cross-section.

3. A stamp as defined in claim 1 wherein said housing is provided with lateral guide grooves, said blocks having gudgeons engaging in said guide grooves.

4. A stamp as defined in claim 3 wherein said drive means includes a pinion on a gudgeon of each block, a ratchet coupling between each pinion and the respective block, and a rack on said housing engageable with said pinion during part of its vertical stroke.

5. A stamp as defined in claim 3 wherein said actuating means comprises a yoke engaging the gudgeons of the upper block and a plunger on said yoke projecting upwardly from said housing.

6. A stamp as defined in claim 5 wherein said spring means comprises separate springs bearing upon said plunger and upon said lower block.

7. A stamp as defined in claim 1 wherein said housing is provided with a door giving access to said ink pads in the elevated position of said upper block.