Apparatus for printing poultry eggs
Disclosed is a stamp head ( 1 ) for printing uneven surfaces, especially agricultural products such as poultry eggs, by means of screen printing. The stamp ink is stored in a tampon ( 5 ) within a stamp chamber ( 2 ) and is transferred to the egg surface with the aid of structures of a small coated screen printing plate ( 4 ). The stamp head ( 2 ) can be fastened to a stamp guiding assembly ( 7 ) via a stamp pressing element ( 10 ) such that an egg stamp ( 50 ) is created which can be vertically moved up and down on a stamp bar ( 18 ), the stamping process being carried out by means of the vertical movement. Several egg stamps ( 50 ) can be mounted on the stamp bar ( 18 ) such that a stamping apparatus is created which allows several eggs to be printed simultaneously.
1. An apparatus for screen printing on a convex surface, the apparatus comprising:
a stamp head having a cylindrical wall that defines a stamp chamber and a covering surface that closes a first end of the stamp chamber;
a tampon for containing stamp ink, disposed within the stamp head, having a convex-curved pressure surface;
a removable, replaceable convex-curved, small screen printing plate that is releasably fastened on the stamp head and stretched across the tampon pressure surface so as to close off a second end of the stamp chamber; and
a small screen printing plate mounting that is structured and arranged in the form of an annular wall and having a radially inwardly directed pressure surface that removably attaches the small screen printing plate to the stamp head and stretches the small screen printing plate across the tampon pressure surface,
wherein the small screen printing plate is adapted to invert from a convex-curved shape to a concave-curved shape so that some portion of the small screen printing plate is introduced into the stamp chamber when said small screen printing plate contacts the surface of the convex surface,
wherein inversion of the small screen printing plate from a convex-curved shape to a concave-curved shape causes compression of the tampon housed within the stamp head and the stamp ink contained therein to pass through the small screen printing plate and onto the convex surface, and
wherein the stretch imparted on the small screen printing plate by the mounting constrains the concave-curved shape of the small screen printing plate to optimize the printing of the stamp ink onto the convex surface.
2. The apparatus according to claim 1 , characterized in that the stamp chamber and the small screen printing plate mounting are connected in a form-fitting and/or force-fitting manner.
3. The apparatus according to claim 1 , characterized in that at least one of the stamp chamber and the small screen printing plate mounting is made from a flexible plastic.
4. The apparatus according to claim 1 , characterized in that the covering surface of the stamp chamber is equipped with a ventilation and re-filling opening.
5. The apparatus according to claim 1 , further comprising a tampon pressing element that is disposed inside of the stamp chamber and that is adapted to press the tampon against the small screen printing plate.
6. The apparatus according to claim 5 , characterized in that the covering surface of the stamp chamber contains a concentric milling to receive the tampon pressing element inside the stamp chamber.
7. The apparatus according to claim 5 , characterized in that the tampon pressing element is a helical spring.
8. An egg stamp apparatus having at least one apparatus according to claim 1 , the egg stamp apparatus further comprising:
a horizontally-disposed stamp bar that is structured and arranged to operate vertically up and down and to accommodate each apparatus of the at least one apparatus;
a stamp guiding assembly that is removably attached to the stamp bar and that is structured and arranged to enable each apparatus of the at least one apparatus to move vertically up and down; and
a stamp pressing element that is structured and arranged to attach each apparatus of the at least one apparatus to the corresponding stamp guiding assembly and to enable the stamp head to incline at a desired angle with respect to the uneven surface.
9. The egg stamp apparatus according to claim 8 , characterized in that the stamp pressing element is selected from the group consisting of a ball joint, a helical spring, a rubber elastic element, and a cardan shaft.
10. The egg stamp apparatus according to claim 8 , characterized in that the stamp guiding assembly includes a stamp pressing weight disposed at a first end of an elongate guide rod and a movement limiter disposed at a second, opposite end of the elongate guide rod.
11. The egg stamp apparatus according to claim 8 , characterized in that the stamp guiding assembly is fastened on the stamp bar with a stamp fastening element.
12. A method of stamping a poultry egg using the egg stamp apparatus according to claim 8 , wherein
stamping the poultry egg includes bringing the apparatus into contact with the convex surface of the poultry egg while said poultry egg is disposed in at least one of an egg tray carton, an egg box or in holding devices of an egg transportation installation.
13. The method according to claim 12 , wherein
bringing the apparatus into contact with the convex surface of the poultry egg includes moving at least one of said poultry egg, said egg tray carton, said egg box or said holding devices towards the apparatus.
14. A method of stamping a poultry egg using the apparatus according to claim 1 , wherein the method comprises:
bringing the apparatus into contact with a convex surface of the poultry egg so that said apparatus surrounds the contacted convex surface.
15. The method according to claim 14 , wherein surrounding the contacted convex surface includes the small screen printing plate adapting to the surface of the poultry egg by inverting from a convex shape to a concave shape towards the stamp chamber so that some portion of the concave shape enters into the stamp chamber.
16. A method of screen printing on a convex surface of a poultry egg using the apparatus according to claim 1 , wherein the method comprises:
bringing the apparatus into contact with the convex surface of the poultry egg so that said stamp head surrounds the convex surface.
17. The method according to claim 16 , further comprising:
disposing the poultry egg in at least one of an egg tray carton, an egg box or in holding devices of an egg transportation installation before the apparatus is brought into contact with the convex surface of the poultry egg.
18. The method according to claim 17 , wherein bringing the apparatus into contact with the convex surface of the poultry egg includes moving said poultry egg, said egg tray carton, said egg box or said holding devices towards the stamp head of said apparatus.
19. The apparatus according to claim 1 , wherein the small screen printing plate is coated with at least one of a light-sensitive photo-emulsion and a light-sensitive film on a delivery side of said small screen printing plate.