| 摘要 |
Apparatus for cutting layups of sheet material and including an elongated table for supporting a layup, a main carriage supported for movement longitudinally of the table and a cutting tool supported on the main carriage for movement therewith and relative thereto in cutting engagement with the layup. The main carriage and the cutting tool move in response to positioning signals received from a numerically controlled or computerized controller. A pair of power driven hold-down rolls positioned at opposite sides of the cutting tool extend transversely of the table and move with the main carriage and in rolling engagement with the upper surface of the layup. At least one of the rolls is driven so that its tangential velocity at its point of contact with the layup is substantially equal to the lineal speed of the main carriage relative to the table but in the opposite direction. Thus, the one roll has a substantially zero velocity relative to the supporting table at its point of contact with the layup and exerts only a downwardly directed force upon the layup. Both rolls may be driven in the aforesaid manner, or, if desired, one of the rolls may be driven at a slightly different speed than the other roll to impart spreading action to the layup in the vicinity of the cutting tool.
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