| 摘要 |
On woodworking machines of the traversing type, for example those used for sanding operations, the items (23) are secured on a vacuum conveyor (3). When the items are not perfectly plane, or when the contact surface against the conveyor is small, the holding power is often not sufficient to allow satisfactory processing operations to be effected without the time-consuming use of devices such as clamping tools or the like. In order to overcome this disadvantage, the machine according to the invention is provided with a number of compressed air nozzles (10) which direct a stream of air towards the items (23), whereby there is achieved a hitherto unknown degree of good retention, even of items which have not hitherto been able to be secured by means of air alone. The nozzles (10) are connected to the pressure side (9) of the air pumps (6), and the suction of the conveyor (3) is connected to the pumps' inlet sides (8), thus hereby creating a closed system with good economy. Finally, there is a reduction in the friction of the belt (13) as well as the wear on the supporting plate (18), this being the result of the formation of eddy currents in some grooves (20), which are formed in the plate (18) and through which the air is sucked. <IMAGE> |
