EP0233895B2

EP0233895B2 - Device for printing spherical objects and the like

Info

Publication number: EP0233895B2
Application number: EP86904310A
Authority: EP
Inventors: Jose Gurpegui
Original assignee: UNICE SA
Current assignee: UNICE SA
Priority date: 1985-07-31
Filing date: 1986-07-21
Publication date: 1995-12-27
Anticipated expiration: 2006-07-21
Also published as: DE3668136D1; EP0233895B1; EP0233895A1; WO1987000796A1; ES545755A0; ES8703346A1

Abstract

A method and device for printing three-dimensional objects, characterised in that the means for transferring the inked design between a flat master surface from which said design is to be picked up and a three-dimensional object which is to be printed is constituted by a hollow resiliently deformable stamp (1) which is preferably hemispherical in shape and which, when pressed onto the master is capable of deformation to provide a flattened surface which allows said pick-up to take place and, when pressed onto a three-dimensional object (5) to be printed is capable of deformation to envelope the object over a surface area of substantially a hemisphere, this being the surface area to receive the inked design.

Description

Technical Field

The invention relates to a device for printing on three-dimensional bodies, and more particularly but not exclusively for printing on spherical or part- spherical bodies, and to a method of printing using such a device.

Background Art

Until now, characters, designs, colours and the like have been printed on spherical objects and the like by the same method as when printing on flat surfaces by methods, including stamping, which use an intermediate element or stamp which picks up an inked design from a master and transfers it to the object to be decorated or printed.
At present, the design solution adopted with said stamps is to make them from solid rubber or similar synthetic materials. This solid form means that, when a spherical object is to be stamped, the adaption of the stamp to the shape of the object takes place solely through elastic deformation of the material of which is is made. Thus the surface area which the stamp can cover is very limited, being confined to small areas. In fact, since the stamp has to be flat in order to be able to take the corresponding inked design from a flat master surface and, since it is solid, adaption of the same to the spherical object takes place solely through elastic deformation of the material of which the stamp is made; therefore, it can only reach very small surface areas.
Solutions designed to solve this problem while retaining the solid design of the stamp and giving it certain moulded shapes corresponding to those of the item to be decorated by printing have not been very successful on account of the complexity of producing such stamps and the means required for the initial transfer of the inked design onto them.
Other proposals have been made. In DE-A-2 855 210 a solid stamp of soft rubber-silicone is used to take colour from a flat plate and transfer it to a pressure pad which transfers the colour to a ball. Three steps are involved. In GB-A-848 076, a hollow cup-shaped stamp is used to transfer a design to a curved surface. In both cases, there is no possibility of printing over a large surface area of substantially a hemisphere.
This is the situation which currently exists, for example, in the synthetic plastics balloon and ball manufacturing industry; these items are either decorated with very limited designs as regards the surface area covered or else recourse is had to successive stamping operations, successively turning the spherical object being stamped, making the printing operation slow and expensive.
At all events, up to now, no process had been found which allows a large surface area of substantially a hemisphere to be stamped in a single operation.

DISCLOSURE OF INVENTION

According to the present invention, this result is achieved by a device for printing three-dimensional objects, comprising a flexible stamp for transferring an inked design between a flat master surface from which said design is to be picked up and a three-dimensional object which is to be printed, which stamp, when pressed on to the master, is capable of deformation to provide a flattened surface which allows said pick-up to take place and, when pressed on to a three-dimensional object to be printed, is capable of deformation to envelope the object over a surface area which receives the inked design, the flexible stamp having a hollow body the interior of which is occupied by a fluid which allows the stamp to be deformed and assists in the elastic recovery of its original shape characterised in that the stamp is substantially hemispherical and is capable of concave deformation to envelope the object to be printed over a surface area of substantially a hemisphere following flattened deformation over substantially the same area for pick-up of the design, and characterised by means through which the fluid leaves the body during deformation and returns automatically when deformation ceases to assist the resilient deformation and recovery of the stamp.
The device is preferably characterised by a plurality of the stamps adapted to operate in synchronism, the interiors of the bodies of the respective stamps being connected together by closed circuit means whereby the fluid can move between the stamps.
From another aspect the invention is a method of printing on the surface of a spherical object using a device as described above, characterised by the steps of pressing the hollow flexible hemispherical stamp against a flat inked master surface whereby the hemispherical surface of the stamp is flattened into surface to surface contact with the stamp so that the design to be printed is transferred to the surface of the stamp, removing the hollow flexible hemispherical stamp from the master surface to permit the stamp to regain its hemispherical shape, pressing the hollow flexible hemispherical stamp against the spherical object so that it envelopes a hemispherical portion of the object and its inked surface is brought into contact with the surface of the object whereby the inked design is transferred to the hemispherical portion of the object. A plurality of the stamps may be used to print different colours on the spherical object.
The method is preferably characterised in that, after printing of said hemispherical portion, the spherical object is turned through 180 and printing by a stamp or stamps is effected on the other hemispherical portion of the object.

BRIEF DESCRIPTION OF DRAWINGS

The invention is diagrammatically illustrated, by way of example, in the accompanying drawings in which:-

Figure 1 is an elevation of a pair of stamps which are ready to operate on respective spherical objects;
Figure 2 is a view similar to that of Figure 1 but with the stamps in contact with the objects to be printed;
Figure 3 is a section of the stamp taken on the line III-III of Figure 1 and
Figure 4 is a section of the stamp taken on the line IV-IV of Figure 1.

Explanatory details

1. - Stamp
2. - Hemispherical hollow stamp body
3. - Stamp support structure
4. - Rod
5. - Object to be printed
6. - Object support.

Best Mode for Carrying out Invention

The object of this invention is a method of and device for printing spherical objects and the like starting from a general printing line which includes the corresponding elements for metering and preparation of inked surfaces and also stamps which are the means of transfer between said inked surfaces and the object to be decorated. According to the invention, each stamp (1), see Figure 1, is constituted by a body in the form of a hollow flexible hemispherical hood (2) which is fixed to a support structure (3) which in turn is fixed to a rod (4) which may be connected to a conventional means which provides the necessary translation, raising and lowering movements.
As can be seen in Figures 3 and 4, the hood (2) consists of a laminar hollow elastic element which, starting from its convex external shape, can adapt to any object through the effect of the pressure exerted by the rod (4), conforming its external surface to that of the object to be printed and, consequently, transferring the inked design to an object equivalent in area to a hemisphere in one step.
As can be seen in Figure 1, the object (5) to be printed, which in this case is a spherical object such as a balloon, is held under the stamp (1) by means of fastening device or support (6).
The printing process, according to the present invention is as follows:
Firstly, each stamp (1) moves until it is located on the flat master template which incorporates the inked design which is to be printed. In this position, the stamp (1) descends, applying pressure, and, since the stamp (1) is hollow and flexible, it deforms and, as it is flattened against the flat template, it adopts the shape of a flattened hemisphere which, at its pole, provides a flat surface constituting a good recipient for the inked design incorporated on the template.
Once the inked design has been transferred to the stamp (1), the latter rises and moves until it is over the object to be printed (5) as shown in Figure 1.
The stamp (1) is then lowered and again, being a hollow flexible body, it deforms and envelopes the object (5) as shown in Figure 2. In this way, it prints the design which it had taken on the flat template on to this object (5) and, through the envelopment of the object (5), said printing can cover practically half of this object (5), i.e. a hemisphere.
The stamp (1) will incorporate a fluid filling material in its hollow interior, which material helps to provide the body (2) with required resiliency and helps it recover its initial shape elastically. In this connection, said filling material, either gaseous or liquid, will leave the body (2) when the latter deforms and return to the inside of the body automatically when the deformation ceases. Thus when several stamps (1) operate in synchronism, the fluid from some of the interiors of some of the stamps can pass into others in closed circuits i.e. while some stamps (1) are being deformed, the others are recovering their initial configuration.

INDUSTRIAL APPLICABILITY

In one possible practical embodiment of a stamping line for spherical objects (5), groups of four stamps (1) will be arranged for the four basic colours of the colour combinations and these four stamps (1) will produce the the corresponding final design which will cover half an object (5), either through successive operation of the same or through simultaneous operation and successive feeding of the objects (5).
It will be sufficient to turn this object (5) through one hundred and eighty degrees or else to arrange groups of stamps (1) in positions opposite one another in order to cover practically all the object (5) in one stamping operation.
Obviously, the description which is given of one possible practical embodiment is not intended- to be taken as limiting since the objects (5) to be printed may have any known three-dimensional shape. These objects (5) can have a convex or else concave form in the external configuration of their surface to be printed or even be flat.

Claims

1. A device for printing three-dimensional objects, comprising a flexible stamp for transferring an inked design between a flat master surface from which said design is to be picked up and a three-dimensional object which is to be printed, which stamp, when pressed on to the master, is capable of deformation to provide a flattened surface which allows said pick-up to take place and, when pressed on to a three-dimensional object to be printed, is capable of deformation to envelope the object over a surface area which receives the inked design, the flexible stamp (1) having a hollow body (2) the interior of which is occupied by a fluid which allows the stamp to be deformed and assists in the elastic recovery of its original shape, characterised in that the stamp (1) is substantially hemispherical and is capable of concave deformation to envelope the object (5) to be printed over a surface area of substantially a hemisphere following flattened deformation over substantially the same area for pick-up of the design, and characterised by means through which the fluid leaves the body during deformation and returns automatically when deformation ceases to assist the resilient deformation and recovery of the stamp (1).

2. A device for printing three-dimensional objects as claimed in claim 1, characterised by a plurality of stamps (1) adapted to operate in synchronism, the interiors of the bodies (2) of the respective stamps being connected together by closed circuit means whereby the fluid can move between the stamps.

3. A method of printing on the surface of a spherical object using a device as claimed in any preceding claim, characterised by the steps of pressing the hollow flexible hemispherical stamp (1) against a flat inked master surface whereby the hemispherical surface of the stamp is flattened into surface to surface contact with the stamp so that the design to be printed is transferred to the surface of the stamp, removing the hollow flexible hemispherical stamp (1) from the master surface to permit the stamp to regain its hemispherical shape, pressing the hollow flexible hemispherical stamp against the spherical object (5) so that it envelopes a hemispherical portion of the object and its inked surface is brought into contact with the surface of the object (5) whereby the inked design is transferred to the hemispherical portion of the object.

4. A method for printing on the surface of a spherical object a claimed in claim 3, characterised in that a plurality of stamps (1) are used to print different colours on the spherical object (5).

5. A method as claimed in claim 3 of claim 4, characterised in that, after printing of said hemispherical portion, the spherical object (5) is turned through 180_° and printing by a stamp or stamps (1) is effected on the other hemispherical portion of the object (5).