Punch for a rotary press

Patent metadata

Field	Value
Publication number	US-10343363-B2
Application number	US-201715660062-A
Country	US
Kind code	B2
Filing date	Jul 26, 2017
Priority date	Jul 26, 2016
Publication date	Jul 9, 2019
Grant date	Jul 9, 2019

Abstract

A punch for a rotary press comprises a shaft with a punch tip at a first end of the shaft and a punch head at the second end of the shaft. The punch head further comprises a mirror surface and a cylindrical surface, as well as intermediate region between the mirror surface and cylindrical surface. The mirror surface defining a central recess surrounded by an annular mirror surface section.

First claim

The invention claimed is:

1. A punch for a rotary press comprising:
a shaft comprising,
a punch tip at a first end of the shaft, and
a punch head at a second end of the shaft, the punch head further comprising
an annular mirror surface section surrounding a recess having one end which is open and a second end which is closed across the opening,
a cylindrical surface, and
an intermediate region disposed between the annular mirror surface and cylindrical surface.

2. The punch according to claim 1 , wherein the recess further comprises an edge region configured to surround a base region.

3. The punch according to claim 2 , wherein the edge region is a conical frustum or a cone.

4. The punch according to claim 2 , wherein a tangentially continuous transitional region is disposed between the edge region and the annular mirror surface.

5. The punch according to claim 2 , wherein a continuously curved transitional region is disposed between the edge region and the annular mirror surface.

6. The punch according to claim 4 , wherein an angle (β) between a tangent at the tangentially continuous transitional region and the annular mirror surface section is less than 20°.

7. The punch according to claim 4 , wherein an angle (β) between a tangent at the tangentially continuous transitional region and the annular mirror surface section is less than 10°.

8. The punch according to claim 1 , wherein a depth of the recess relative to the annular mirror surface is less than 4 mm.

9. The punch according to claim 1 , wherein a depth of the recess relative to the annular mirror surface is less than 1 mm.

10. The punch according to claim 1 , wherein a ratio between a depth of the recess to a diameter (dl) of the recess is less than 2.

11. The punch according to claim 1 , wherein a ratio between a diameter (d 1 ) of the recess to a diameter of the annular mirror surface is less than 0.8.

12. The punch according to claim 1 , wherein an outer contour of the recess is disposed within an envelope circle with a diameter (d 1 ) which is not greater than one-half a diameter (d 2 ) of a region of the shaft adjacent to the punch head.

13. The punch according to claim 1 , wherein a contour of the recess is disposed within an envelope cone, or envelope conical frustum, with a taper angle (α) of at least 140° and a maximum diameter (d 1 ) which is not greater than one-half a diameter (d 2 ) of a region of the shaft adjacent to the punch head.

14. The punch according to claim 1 , wherein a height (h) of all wall sections of the recess perpendicular to the annular mirror surface section is less than 1 mm.

15. A rotary press comprising:
a rotor configured to be rotated by means of a rotary drive, the rotor comprising
an upper punch guide configured to guide upper punches of the rotary press,
a lower punch guide configured to guide lower punches of the rotary press, and
a die plate disposed between the upper and lower punch guides having a plurality of cavities configured to interact with the upper and lower punches;

a filling apparatus configured to add filling material to the plurality of cavities in the die plate;
at least one upper pressing apparatus and at least one lower pressing apparatus configured to interact with the upper punches and the lower punches during operation to press the filling material into the plurality of cavities in the die plate; and
an ejection apparatus configured to eject pellets generated in the plurality of cavities from the rotary press,
wherein at least one of the punches of the rotary press comprise a shaft having a punch head at one end of the shaft, the punch head comprising an annular mirror surface section surrounding a recess having one end which is open and a second end which is closed across the opening, a cylindrical surface, and an intermediate region disposed between the annular mirror surface and cylindrical surface.

Assignees

• Fette Compacting Gmbh
• Fette Eng Gmbh

Inventors

• Heinrich Thomas
• Luedemann Stefan

Classifications

• B30B11/04

  co-operating with a fixed mould · CPC title

• B30B11/08 Primary

  co-operating with moulds carried by a turntable · CPC title

• B30B15/302

  Feeding material in particulate or plastic state to moulding presses · CPC title

• B30B15/0076

  Noise or vibration isolation means · CPC title

• B30B15/065 Primary

  Press rams · CPC title