RELEASABLE GRIP-AND-HOLD DEVICE FOR LIFTING LARGE BOARDS AND A METHOD FOR RELEASING THE DEVICE IN THE LARGE BOARD'S MOUNTING POSITION

摘要

A releasable grip-and-hold device for panelling boards (28), pivotally mounted on the extreme end of a pivoted boom (18) of liftable/lowerable board-handling apparatus. Said device comprises a board-supporting frame (26) with hooks (32) for securely holding opposite board edges until the moment of release from the device in the mounting position of the board. The hooks (32) are formed on respective end sections (34) of said frame (26) and are connected to the frame (26) in a pivoted, spring-loaded manner. A wire (62) leads from a fixed point (60) on the supporting frame (26) at the pivot point (30) thereof, to a constructional element on the board-handling apparatus. When the boomwork (18) is pivoted, the wire (62) provides for the supporting frame (26) to be rotated 180 DEG from a stack of panelling boards (28) lying horizontally, and so that the supporting frame (26) with the panelling board (28) lying on top is sloping slightly in the longitudinal direction. This sloping position of the panelling board (28) resting on top of the supporting frame (26) via small pivoted supporting means (44), then bringing it into a displacing motion, so that it first pivots the supporting means (44) and then exerts a push force on the hooks (34), which pivot resiliently away in order to start the successive release of the panelling board (28) from its grip-and-hold device.