| 摘要 |
A material handling vehicle 10, e.g. a forklift, has an extendable boom 15 raised and lowered by a first drive means (17, fig 4), and extended and retracted by a second drive means (20, fig 4). A material handling implement 21 comprising a carrier (25, fig 5), a load engaging device (30, fig 5) relatively movable to the carrier, and a first sensing means (39, fig 5) which senses a position of the device relative to the carrier, is mounted on the end of the boom. The drive means are responsive to the first sensing means at a certain position, the operation of the drive means is modified accordingly. There may be a second sensing means (39, fig 5) located on the handling implement to sense a second position of the device relative to the character, and also modify operation of the drive means. The sensing means are preferably proximity switches, and one of them may detect relative vertical movement between the device and carrier, while the other may detect relative angular movement. There may also be a third sensing means to determine a predetermined orientation of the carrier relative to vertical, and a mode sensing means to determine the angular orientation of the boom relative to vertical. |
