| 摘要 |
A buffer store for a flat web material includes two roller registers having freely rotatable rollers movable relative to one another in a direction radial to a roller axis, thereby forming loops of the web material between the rollers, a piston-cylinder arrangement having a chamber containing a compressible medium and acting as a spring between the registers to generate web tension in the material, and a control-valve arrangement that switches between a first condition, for normal operation, and a second condition, for operation during a fault. In the first condition, the control-valve arrangement connects the cylinder chamber of the piston-cylinder arrangement to a device for providing a constant operating pressure. In the second condition, the control-valve arrangement closes the cylinder chamber of the piston-cylinder arrangement and connects it to a relief valve that relieves pressure therein to a residual pressure significantly smaller than the operating pressure. |
| 主权项 |
1. An apparatus comprising a buffer store for guiding flat web material, said buffer store comprising a first roller register, a second roller register, a pivot arm, a first set of rollers on said first roller register, a second set of rollers on said second roller register, a piston/cylinder arrangement, a control device, and a relief valve, wherein said rollers in said first set of rollers are freely rotatable, wherein said rollers in said second set of rollers are freely rotatable, wherein said first set of rollers comprises a first roller that rotates about a roller axis, wherein said roller axis defines a radial direction that is perpendicular to said roller axis, wherein said first roller register is moveable relative to said second roller register along said radial direction, wherein said first roller register and said second roller register are structurally configured to cooperate in forming loops of said flat web material between rollers of said first set of rollers and rollers of said second sets of rollers, wherein said loops have lengths that vary in response to movement of at least one of said first and second roller registers, wherein said pivot arm supports one of said first roller register and said second roller register, wherein said pivot arm is characterized by a mass, wherein said piston-cylinder arrangement comprises a cylinder chamber, wherein, in operation, said cylinder chamber contains a compressible pressure medium, wherein, as a result of said compressible pressure medium in said cylinder chamber, said piston-cylinder chamber is structurally configured to operate as a spring between said first roller register and said second roller register, wherein, in operation, said piston-cylinder chamber causes web tension in said flat web material as said flat web material is guided through said buffer store, wherein said control device comprises a first control valve arrangement, wherein said first control valve arrangement is configured to switch between operating in a first condition and operating in a second condition, wherein said control device is configured to cause said first control valve arrangement to switch into operating in said first condition during normal operation of said buffer store, wherein said control device is configured to cause said first control valve arrangement to switch into operating in said second condition during abnormal operation, wherein said abnormal operation is selected from the group consisting of a operation during a machine standstill and operation during a machine fault, wherein, when said first control valve arrangement is operating in said first condition, said first control valve arrangement connects said cylinder chamber of said piston-cylinder arrangement to a pressure source for providing a normal operating pressure, wherein, when said first control valve arrangement is operating in said second condition, into which said first control valve arrangement is switched in the event of one of a machine standstill and a fault, said first control valve arrangement traps pressure medium in said cylinder chamber, thereby causing said cylinder chamber to assume a selected abnormal operating pressure, wherein said selected abnormal operating pressure is a function of said mass of said pivot arm, wherein said selected abnormal operating pressure is above atmospheric pressure, and wherein said selected abnormal operating pressure is below said normal operating pressure, and wherein, to transition into said second condition, said first control valve arrangement connects said cylinder chamber to said relief valve, thereby causing pressure in said cylinder chamber to decrease from said normal operating pressure to said abnormal operating pressure, wherein said first control valve arrangement is configured such that when pressure from said pressure medium at said first control valve arrangement falls below a threshold, said first control valve arrangement assumes said second condition thereof in response. |
