Tensioning mechanism for a circulating element
A tensioning apparatus for a circulating element, such as a belt or a band, has a basic body in which a first chamber is formed. A piston is positioned in the first chamber and carries a piston rod. The piston can be displaced in the first chamber by the use of a pressure fluid. Either the piston rod or the base body is attached to the carrier for the belt or band. Either the piston rod or the basic body carries a head piece which can be moved in contact with the circulating element. A locking mechanism for the piston rod can be engaged and disengaged by the use of fluid pressure.
1. A tensioning mechanism for a circulating element, comprising:
a main body;
a first chamber is formed in the main body;
a piston in the first chamber, which piston can be displaced within the first chamber by a pressurized fluid;
a piston rod connected to, and driven by the piston;
a support, the main body being securely mounted on the support;
a head piece secured to the piston rod and which can be moved by the piston rod into contact with the circulating element;
a lock mechanism in the main body and separate from the first chamber in which the piston is displaceable, the lock mechanism being usable to lock the piston rod in a selected position, which lock mechanism is controllable using pressurized fluid;
at least one second chamber, in the main body and separate from the first chamber in which the piston is displaceable, the lock mechanism being positioned in the second chamber which is pressurizable with the pressurized fluid to control the lock mechanism for releasably locking the piston rod in a selected position;
an opening, in the main body and through which the piston rod passes, wherein the second chamber is arranged on a first side of the opening; and
an abutment which is securely attached to the main body, a second side of the opening, which is opposite the first side of the opening, is being formed by the abutment.
2. A tensioning mechanism for circulating element, comprising:
a main body;
a first chamber formed in the main body;
a piston in the first chamber, which piston can be displaced within the first chamber by a pressurized fluid,
a piston rod connected to, and driven by the piston;
a support, the main body being securely mounted on the support;
a head piece secured to the piston rod and which can be moved in by the piston rod into contact with the circulating element;
a lock mechanism in the main body and separate from the first chamber in which the piston is displaceable, the lock mechanism being useable to lock the piston rod in a selected position, which lock mechanism is controllable using pressurized fluid;
at least one second chamber, in the main body and separate from the first chamber in which the piston is displaceable, the lock mechanism being positioned in the second chamber which is pressurizable with the pressurized fluid to control the lock mechanism for releasably locking the piston rod in a selected position; and
at least one sensor, the at least one sensor being arranged to at least one of directly and indirectly detect the position of at least the piston rod supported by the main body.
3. The tensioning mechanism according to claim 1 , characterized in that the at least one second chamber is pressurized with pressurized fluid to lock the piston rod in position.
4. The tensioning mechanism according to claim 1 , characterized in that the at least one second chamber is void of the pressurized fluid to release the mechanism for locking the piston rod in position.
5. The tensioning mechanism according to claim 1 , characterized in the that the at least one second chamber contains one of a displaceable piston and a clamping pad.
6. The tensioning mechanism according to claim 5 , characterized in that, when the at least one second chamber is pressurized with pressurized fluid, the displaceable piston is forced against the piston rod.
7. The tensioning mechanism according to claim 5 , characterized in that a compression spring is arranged in the at least one second chamber to force the clamping pad against the piston rod to lock the piston rod in position.
8. The tensioning mechanism according to claim 1 , characterized in that the at least one second chamber is bounded by a membrane, which membrane when the at least one second chamber is pressurized with the pressurized is forced against the piston rod.
9. The tensioning mechanism according to claim 2 , characterized in that the piston rod is guided through an opening in the main body and through which the piston rod passes, wherein the second chamber is arranged on a first side of the opening, and further including an abutment, which is securely attached to the main body, a second side of the opening, which is opposite the first side, of the opening being formed by the abutment.
10. The tensioning mechanism according to claim 1 , further including a plurality of said second chambers and wherein the forces exerted on the piston rod by the plurality of second chambers pressurized with the pressurized fluid compensate for one another.
11. The tensioning mechanism according to claim 1 , characterized in that the piston rod is divided into a plurality of piston rod branches and wherein an area of the main body which contains the second chambers is arranged between spaced ones of the piston rod branches.
12. The tensioning mechanism according to claim 11 , characterized in that each of the spaces ones of the piston rod branches is connected at two ends to a frame, which encompasses the area of the main body arranged between the space ones of the piston rod branches.
13. The tensioning mechanism according to claim 11 , characterized in that the first chamber is also situated in the area of the main body that is arranged between the spaced ones of the piston rod branches.
14. The tensioning mechanism according to claim 1 , characterized in that the piston in the first chamber a dual action piston.
15. The tensioning mechanism according to claim 1 , further including supply couplings, which are usable for supplying the first and second chambers with the pressurized fluid, are positioned, aligned in pairs, and communicating with one another on opposite sides of the main body.
16. The tensioning mechanism according to claim 1 , characterized in that the main body has a bore hole which is configured to hold the support.
17. The tensioning mechanism to claim 16 , characterized in that a direction of alignment of the communicating supply couplings is parallel to the bore hole.
18. The tensioning mechanism according to claim 16 , characterized in that the first and second chamber and the head piece are arranged on opposite side of the bore hold.
19. The tensioning mechanism according to claim 1 , characterized in that the circulating element is a belt.
20. The tensioning mechanism according to claim 19 , characterized in that the belt is in a folding unit of a printing press.
21. The tensioning mechanism according to claim 20 , characterized in that the tensioning mechanism cooperates with a belt of a belt system that is situated upstream, in a direction of material travel, of folding blade cylinder.
22. The tensioning mechanism according to claim 20 , characterized in that the tensioning mechanism cooperates with a belt of a belt system that is situated downstream; in a direction of material travel, of a folding jaw cylinder.
23. The tensioning mechanism according to claim 1 , characterized in that the piston rod can be steplessly locked in position by the lock mechanism.
24. The tensioning mechanism according to claim 1 , characterized in that the at least one second chamber is adapted to be pressurized with the pressurized fluid independently of the first chamber.
25. The tensioning mechanism according to claim 1 , characterized in that in one operating state of the tensioning mechanism the first chamber is pressurized with pressure medium and the second chamber is pressureless.
26. The tensioning mechanism according to claim 1 , further including at least one shared guide roller for a plurality of piston rods.
27. The tensioning mechanism according to claim 26 , characterized in that one shared guide roller is provided for all of the plurality of piston rods.
28. The tensioning mechanism according to claim 26 , characterized in that two shared guide rollers are provided for the plurality of piston rods.
29. The tensioning mechanism according to claim 1 , characterized in that at least one sensor is arranged to one of directly and indirectly detect the position of the piston rod supported by the main body.
30. The tensioning according to claim 1 , characterized in that a plurality of the tensioning mechanisms are arranged side by side.
31. The tensioning mechanism according to claim 1 , characterized in that a plurality of tensioning mechanisms are held by two end plates.
32. The tensioning mechanism according to claim 31 , characterized in that at least one end plate has a coupling that is usable for supplying the pressure medium.
33. The tensioning mechanism according to claim 31 , characterized in that at least one end plate has a sensor for detecting the position of the piston rod supported by the main body.
34. The tensioning mechanism according to claim 1 , characterized in that the tensioning mechanism has a reference element that can be moved along with the piston rod supported by the main body.
35. The tensioning mechanism according to claim 29 , characterized in that a sensor is provided for detecting the position of all tensioning mechanisms.
36. The tensioning mechanisms according to claim 1 , characterized in that head piece is configured as a pulley which is secured to the piston rod remote from the main body and which pulley is engageable with the circulating element.