Abstract: A printing material composed of an open-cell sponge rubber capable of including therein a colored ink, which does not necessitate a stamp pad for the stamping operation, is disclosed. This printing material is prepared by adding appropriate amounts of soluble starch and a fine powder of an easily water-soluble salt which does not decompose or gasify at a curing temperature to a mixture of a starting rubber, a curing agent and a filler, kneading and milling the mixture, introducing the mixture into a mold, heating the mixture to effect curing, removing said starch and salt by washing, and drying the resulting product.

Abstract: An endless printing belt for a rotary rubber stamp, which comprises an endless rubber belt body having a plurality of printing letter sections on a surface thereof and a reinforcing endless belt fabric embedded in back side of said endless belt body, said endless belt fabric being woven by wefts including stainless steel fine wires disposed in parallel to one another in the lengthwise direction and warps including filamentary yarns.

Abstract: A rotary stamp comprises an upper frame including printing members formed on endless belts and a lower frame including another printing member and when the upper frame is pressed down, the printing members of the endless belts are located on a plane common with the other printing member of the lower frame and printing is accomplished simultaneously by these printing members, vertical slots are formed on the side plates of the upper frame and spring means having projections capable of being engaged with these slots and sliding along these vertical slots are disposed in the lower frame.

Abstract: A stamp for imprinting the date, time, name of an organization or company, and so on, which comprises a subsidiary imprint body having on its surface a plurality of circumferentially arranged subsidiary imprint sections, and a disc-shaped main imprint body having on its surface a main imprint section and a marking to be directed to any one of said subsidiary imprint sections, in which said main imprint body is arranged in a central opening of said subsidiary imprint body such that the former is rotatable therein relative to the latter, whereby a desired combination of said main imprint section and one of the subsidiary imprint sections can be selectively attained by turning the main imprint body relative to the subsidiary imprint body, for example, by hand.

Abstract: In a writing instrument comprising a writing core and an ink tank, the contact of the writing core with the ink in the ink tank is intercepted so that unnecessary loss of the ink due to evaporation from the core surface and excessive supply of the ink to the core are effectively prevented. Merely pressing the end portion of the outer case of the writing instrument allows a spring, a valve member and a flexible bellows portion of the ink tank to supply an appropriate amount of ink into the core.

Abstract: This hand stamp comprises a frame; an ink absorber, a printing body, said printing body including a letter portion disposed to project slightly from the end of the said frame body, a leg frame arranged and supported on the outside of said frame to surround said frame, said leg frame being mounted so that it can project from or cave in from the position of said letter portion and said leg frame having an opening allowing said letter portion to pass therethrough; and spring means for pushing said leg frame to project said leg frame from the position of said letter.

Abstract: A rotary date stamp comprising first rotary members supported rotatably on a fixed shaft, each having an annular disc, a cylindrical shaft supported rotatably on the fixed shaft and having an annular disc, a second rotary member supported on said cylindrical shaft so that it can rotate together with said cylindrical shaft, a third rotary member having an annular disc and being loosely supported on said cylindrical shaft so that it can not rotate together with said cylindrical shaft and endless belts hung around the rotary members and having letters on the surface.

Abstract: The invention discloses a rotary rubber stamp comprising a frame body with side openings, a bridge piece mounted to the lower ends of the frame body, rotary cylinders rotatably mounted nearly the center of the frame body, endless stamp belts made of porous rubber material containing continuous foam and mounted circularly around the rotary cylinders and the bridge piece, and rotary disks secured to the rotary cylinders and having their peripheral edges partially extend out of said openings, characterized by the provision of partition plates between the adjacent rotary disks and endless stamp belts.