1315398 Trimming apparatus G BUSCH 28 Sept 1970 [30 Sept 1969 (2)] 46128/70 Head. ing B4B A knife-cutter press for, e.g. trimming the edges of books, comprises a supply mechanism 13 for automatically charging the press with stacks of books to be trimmed and a feed arrangement for forwarding the books to a hollow knife tool of the press, the feed arrangement including a V-shaped holder 1, 2 which can be raised and lowered in synchronism with the movements of a piston or ram of the press. The holder comprises a pair of plates 1, 2 connected by a hinge 3, the plate 1 being coupled by a boss 7 to the rod 8 of a piston 9 which is reciprocable in a cylinder 10 fed by hydraulic or pneumatic fluid; the plates need not be hinged. In a lowered position of the holder a stack of, e.g. books are fed thereon by the supply mechanism comprising grippers (16), Fig. 3 (not shown) reciprocably mounted on chains (17). One edge of the plate 2 is provided with rollers which are arranged to run in guide slots 19 formed in a fixed fence 19. The hollow knife tool comprises a mouthpiece 20, 21, 24, 25 to which is connected the knife 31 having cutting edges 36. Air is fed to the wall 21 of the mouthpiece via passages 26, 28 in order to form a supporting air cushion for the stack which is pushed through the mouthpiece against the knife edges by means of a ram (not shown). Air is also fed to the wall 21 via passages 27, 29 in order to blow away waste material. Additional slitting knives 32 are provided for severing the folded over edges of booklets before the latter engage the trimming knife 30. Spring-loaded plates 22, 23 are mounted in the mouthpiece to accurately position the booklets.