STRAP EMBOSSING SYSTEM

TECHNICAL FIELD

The present invention relates to a system for embossing plastic straps, which, as is known, consists in engraving a diamond pattern on the strap.

BACKGROUND ART

Strap embossing systems comprise two embossing rollers, between which the strap is fed to engrave it on both sides. As is known, the size of the engraving varies according to the size of the strap, so different diamond patterns require either a number of embossing systems (one for each pattern size) or changing the rollers. Obviously, purchasing a number of systems involves considerable cost, whereas the second solution involves stopping the system to change the rollers, with all the cost this entails.

DISCLOSURE OF INVENTION

It is an object of the present invention to provide a strap embossing system designed to eliminate the aforementioned drawbacks, i.e. which provides for fast pattern selection.

According to the present invention, there is provided a system for embossing straps, comprising a

bottom embossing roller and a top embossing roller, and characterized in that each of said rollers comprises a number, of adjacent rings on its lateral surface; each said ring having a respective pattern; and each ring on said bottom roller with a given pattern being positioned facing a ring on said top roller with the same pattern.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be described with reference to the attached drawing, which shows a preferred embodiment of a system, indicated as a whole by 1, for embossing straps 2, and comprising: a bed 3 ; a vertical plate 4 supported on top of bed 3; means 5 for adjusting the position of plate 4 with respect to bed 3 along a horizontal axis X; a first embossing roller 6 fitted to plate 4 and having an axis of rotation parallel to axis X; a second embossing roller 7 parallel to roller 6, at a higher level than roller 6, and also fitted to plate 4; means 8 for adjusting the position of roller 7 along a vertical axis; a first electric motor 11 for powering roller 6; and a second electric motor 12 for powering roller 7.

BEST MODE FOR CARRYING OUT THE INVENTION

System 1 has a vertical work axis Y perpendicular to axis X; and an axis Z perpendicular to axes X and Y,

and along which strap 2 is fed between the two rollers 6 and 7 ^' by known means not shown. Means 5 comprise an electric motor 13 fitted to bed 3 and having, on its drive shaft 15, a screw-nut screw coupling, the screw of which is defined by shaft 15, and the nut screw 16 of which is integral with plate 4. Needless to say, means 5 may have no motor 13, and adjustment may be made using a knob to turn a screw engaging nut screw 16.

Means 8 comprise two preferably hydraulic actuators 17 fitted to a top portion of plate 4, and each having a respective rod 18 fixed to a corresponding sleeve 21; a first sleeve 21 housing, by means of a bearing 22, a first axial end of the hub 23 of roller 7; and a second sleeve 21 housing, by means of a bearing 24, a second axial end of hub 23. The output shaft 25 of motor 12 is fitted to hub 23. To adjust the position of roller 7, motor 12 is also connected by a bracket 26 to an actuator 17. Alternatively or before adjusting the position of roller 7, shaft 25 is obviously disconnected from hub 23, or these may be connected by a joint allowing adjustment of the position of roller 7.

Each roller 6, 7 has a number of adjacent rings 31 on its lateral surface; each ring 31 having a respective pattern; and each ring 31 on roller 6 with a given pattern being positioned facing a ring 31 on roller 7 with the same pattern. System 1 comprises an electronic central control unit 32 for controlling means 5 and 8 and motors 11 and 12 , and to which is connected a block

33 by which to select the pattern to be engraved on strap 2.

In actual use, to extract the strap 2 currently being worked, central control unit 32 commands upward translation of roller 7, which is performed by actuators

17 drawing roller 7 upwards . Once rollers 6 and 7 are parted, central control unit 32 commands means 5 to position plate 4 with respect to bed 3, i.e. to align with work axis Y the rings 31 on rollers 6 and 7 corresponding to the pattern selected by block 33. Once plate 4 and, hence, the selected rings 31 of rollers 6 and 7 are positioned, strip 2 is inserted between rollers 6 and 7 and along axis Z, roller 7 is restored to the work position, and strap 2 is embossed by means of motors 11 and 12. Obviously, roller 7 is positioned taking into account the thickness of strap 2.

The advantages of the present invention will be clear from the foregoing description.

In particular, a system is obtained which provides for changing the strap embossing pattern quickly and easily, with only a few minutes' downtime and, hence, with all the cost advantages this entails.

Clearly, changes may be made to system 1 as described and illustrated herein without, however, departing from the scope of the present invention.

In particular, both plate 4 and roller 7 may be adjusted manually by the operator.