MANUALLY OPERATED PRESS HAVING AN OVERLOAD PROTECTION

• US 20080173191A1
• Filed: 01/11/2008
• Published: 07/24/2008
• Est. Priority Date: 07/13/2005
• Status: Active Grant

• Current Assignee: Gebr. Schmidt Fabrik fuer Feinmechanik GmbH & Co. KG.
• Original Assignee: Gebr. Schmidt Fabrik fuer Feinmechanik GmbH & Co. KG.
• Inventors: Sutermeister, Peter, Babiel, Hartmut
• Granted Patent: US 7,562,622 B2
• Time in Patent Office: Days
• US Class Current: 100/292
• CPC Class Codes: B30B 1/24 by rack-and-pinion means B30B9/3067 takes precedence
• CPC Class Codes: B30B 15/0094 Press load monitoring means B30B15/281 takes precedence
• CPC Class Codes: B30B 15/10 Brakes specially adapted for presses brakes in general F16D
• CPC Class Codes: B30B 15/12 Clutches specially adapted for presses clutches in general F16D
• CPC Class Codes: B30B 15/142 controlling the brake or the clutch
• CPC Class Codes: B30B 15/281 overload limiting devices in general F16H35/10

Abstract

A manually operated press comprises an actuation lever coupled to a shaft assembly. An actuation of the actuation lever is transformed into a stroke movement of a press ram coupled to the shaft assembly and, accordingly, into a change of a relative displacement position of the press ram. A clutch assembly is provided for interrupting a flow of force between the actuation lever and the press ram. The shaft is at least two-piece, namely configured with an input shaft and an output shaft. The clutch is adapted to separate the input shaft from the output shaft depending on the pressing force and/or the relative displacement position of the press ram. The shaft assembly comprises an input shaft and an output shaft. The input shaft extends as an inner shaft through the output shaft being configured as a hollow shaft. The clutch assembly has a first clutch designed as a stroke stop for immobilizing the input shaft with a housing of said press depending on pressing force and/or relative displacement position of the press ram, and a second clutch designed as an overload clutch for interrupting a flow of force between the input shaft and the output shaft.

Claims

1. A manually operated press comprising an actuation member coupled to a shaft, an actuation of said actuation member being transformed into a stroke movement of a press ram coupled to said shaft and, accordingly, into a change of a relative displacement position of said press ram, and a clutch for interrupting a flow of force between said actuation member and said press ram, wherein said shaft is at least two-piece, namely configured with an input shaft and an output shaft, said clutch being adapted to separate said input shaft from said output shaft depending on at least one press parameter of a group of press parameters comprising pressing force and relative displacement position of said press ram.

2. The manually operated press of claim 1, wherein a first sensor is provided for sensing said pressing force.

3. The manually operated press of claim 2, wherein a control unit is provided coupled to said clutch and, further, to said first sensor for supplying clutch signals to said clutch.

4. The manually operated press of claim 3, wherein said control unit supplies a clutch signal for keeping said clutch closed when said sensed pressing force is smaller than a predetermined threshold value.

5. The manually operated press of claim 3, wherein said control unit supplies a clutch signal for opening said clutch when said pressing force is greater than or equal to a predetermined threshold value.

6. The manually operated press of claim 1, wherein a second sensor is provided for sensing said relative position of said press ram.

7. The manually operated press of claim 6, wherein a control unit is provided coupled to said clutch and, further, to said second sensor for supplying clutch signals to said clutch.

8. The manually operated press of claim 7, wherein said control unit supplies a clutch signal for keeping said clutch closed when said sensed relative displacement position of said press ram is smaller than a predetermined threshold value.

9. The manually operated press of claim 7, wherein said control unit supplies a clutch signal for opening said clutch when said relative displacement position of said press ram is greater than or equal to a predetermined threshold value.

10. The manually operated press of claim 1, wherein said actuation member is secured against rotation to said input shaft.

11. The manually operated press of claim 1, wherein said press ram is constantly operatively connected to said output shaft.

12. The manually operated press of claim 1, wherein, further, a stroke stop is provided for immobilizing said input shaft.

13. The manually operated press of claim 12, wherein said stroke stop comprises a brake disc and a brake magnet.

14. The manually operated press of claim 13, wherein said brake disc is secured against rotation to said input shaft, said brake magnet being secured to said press in a stationary manner such that said input shaft is adapted to be immobilized.

15. The manually operated press of claim 13, wherein, further, a third sensor is provided for sensing said relative displacement position of said input shaft, wherein said brake disc is configured such that said third sensor senses said relative displacement position in cooperation with said brake disc.

16. The manually operated press of claim 1, wherein, further, a return assembly is provided being coupled to said input shaft for moving said actuation member into an initial position.

17. The manually operated press of claim 16, wherein said return assembly is configured as a spring,

18. The manually operated press of claim 1, wherein said actuation member is a manually operable lever, said input shaft being an inner lever shaft and said output shaft being an outer hollow shaft.

19. The manually operated press of claim 6, wherein said second sensor is a linear incremental displacement position measuring system sensing displacement position marks coupled to said press ram.

20. The manually operated press of claim 1, wherein said first and said second shaft are interconnected by said clutch in a form-fitting manner for transforming said stroke movement.

21. The manually operated press of claim 20, wherein said form-fitting connection is achieved by means of a toothing having a latch position.

22. A manually operated press comprising a shaft assembly being configured at least two-piece, namely with an input shaft and an output shaft, said input shaft extending as an inner shaft through said output shaft being configured as a hollow shaft, an actuation member coupled to said shaft assembly, an actuation of said actuation member being adapted to be transformed into a stroke movement of a press ram coupled to said shaft assembly, and a clutch assembly having a first clutch designed as a stroke stop for immobilizing said input shaft with a housing of said press depending on at least one press parameter of a group of press parameters comprising pressing force and relative displacement position of said press ram, and a second clutch designed as an overload clutch for interrupting a flow of force between said input shaft and said output shaft.

23. The manually operated press of claim 22, wherein a first sensor is provided for sensing said pressing force.

24. The manually operated press of claim 23, wherein a control unit is provided coupled to said clutch assembly and, further, to said first sensor for supplying clutch signals to said clutch assembly.

25. The manually operated press of claim 24, wherein said control unit supplies a clutch signal for keeping said second clutch closed when said sensed pressing force is smaller than a predetermined threshold value.

26. The manually operated press of claim 24, wherein said control unit supplies a clutch signal for opening said second clutch when said pressing force is greater than or equal to a predetermined threshold value.

27. The manually operated press of claim 22, wherein a second sensor is provided for sensing said relative position of said press ram.

28. The manually operated press of claim 27, wherein a control unit is provided coupled to said clutch and, further, to said second sensor for supplying clutch signals to said clutch.

29. The manually operated press of claim 28, wherein said control unit supplies a clutch signal for keeping said clutch closed when said sensed relative displacement position of said press ram is smaller than a predetermined threshold value.

30. The manually operated press of claim 28, wherein said control unit supplies a clutch signal for opening said clutch when said relative displacement position of said press ram is greater than or equal to a predetermined threshold value.

31. The manually operated press of claim 22, wherein said first clutch comprises a brake disc and a brake magnet.

32. A method for protecting a manually operated press against mechanical overload, said press having an actuation member coupled to a shaft, an actuation of said actuation member being transformed into a stroke movement of a press ram coupled to said shaft and, accordingly, into a change of a relative displacement position of said press ram, and a clutch for interrupting a flow of force between said actuation member and said press ram, wherein said shaft is at least two-piece, namely configured with an input shaft and an output shaft, said clutch being adapted to separate said input shaft from said output shaft depending on at least one press parameter of a group of press parameters comprising pressing force and relative displacement position of said press ram against overload, the method comprising the steps of:

closing said clutch;

sensing at least one of said press parameters;

determining whether said press parameter has reached a predetermined threshold value; and

if said predetermined threshold value has been reached, actuating said clutch for separating said at least two shafts from each other.

33. The method of claim 32, wherein a stroke stop is closed before said clutch separates said shafts.