US 4,709,872 AGranted

Web tension control and emergency stop system

AssigneeMAN Roland Druckmaschinen AG

InventorsJosef Hammer, Walter Handschuher

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Abstract

To provide for controlled braking effort on a selected paper roll (5) from which a web (14) is applied to a utilization machine, and additionally for fast-stop or holding conditions, the roll is coupled to an operating disk brake (10) which receives braking pressure from a regulated pressure source. Additionally, rapid-stop brake calipers forming a rapid-stop brake (11) are applied to the disk, preferably having a higher braking friction coefficient, and controlled from the regulated pressure via a fluid disjunctive or OR-gate valve (42). A magnetic valve (36), controlled by a computer-controller (28), selectively switches the controlled fluid pressure through the OR-gate valve (42) only to the operating brake or to the fast-stop brake and, via a branch connection (46a), also to the operating brake. Under high emergency conditions, or to hold a roll stopped, for example for roll changing, unregulated pressure can be applied to both the operating brake (10) and the fast-stop brake (11) by a further electromagnetically controlled valve (38) connected through a further OR-gate valve (44) to the second output of the first electromagnetically controlled valve (36).

Web tension control and combined rapid-stop system, particularly for paper webs being delivered to a rotary web printing machine, said system having

a roll support carrier (1, 2, 3) for supporting at least one roll (4, 5) on which the web (14) is wound;
a first brake forming an operating brake (10) secured to the support carrier for braking the at least one roll upon unwinding thereof;
a second brake forming a fast stop brake (11) secured to the support carrier and additionally braking the at least one roll for fast stopping condition;
a movably journaled tension or compensating roller (17) about which the web (14), unreeled from the at least one roll is looped;
a tension sensing means (21, 24) for sensing the position of the tension or compensating roller and for providing a tension signal;
a computer-controller unit (28) receiving the tension signal, and
a source of fluid pressure (29),
and comprising
an electrically controllable fluid pressure regulator (26) receiving pressurized fluid from said source (29) connected to and controlled by the computer-controller unit (28) and providing fluid pressure output at a regulated pressure level, as commanded by said computer-controller unit (28);
an electrically controlled magnetic valve (36) having two pressure fluid outputs (41, 43) connected to and controlled by said computer-controller unit (28);
means (35) for supplying pressure fluid from said fluid pressure regulator (26) to said valve (36);
a fluid disjunctive or OR-gate valve (42) having a fluid output connection (47) connected to and controlling the operating brake (10);
an operating brake fluid connecting (41) from a first output of the electrically controllable magnetic valve (36) to a first input of the fluid disjunctive or OR-gate valve (42);
a stop brake fluid pressure connection (43, 44, 46, 46b) from a second output of the electrically controllable magnetic valve (36) to the fast-stop brake (11);
and
a further branch connection (46a) from said second output of the electrically controlled magnetic valve (36) to a second input of the fluid disjunctive or OR-gate valve (42),
to provide
(a) for normal operation, controlled fluid pressure to the operating brake (10) via the first input of the OR-gate valve (42), and
(b) under fast-stop conditions or emergency conditions, controlled fluid pressure to the fast-stop brake (11) via the fast-stop brake fluid pressure connection and further to the operating brake (10) via said further branch connection (46, 46a) to the OR-gate valve (42).

16 more elements

Abstract

Claims14