| 摘要 |
1310781 Incising wood KARL RICHTBERG KG 25 March 1971 7815/71 Heading B5L [Also in Division D1] A pole is prepared for impregnation by forming a plurality of elongate incisions in its surface, with an array of blades, each incision extending along the grain of the pole, and the incisions being arranged in groups extending round the pole, the groups being axially spaced from one another and the incisions of adjacent groups being circumferentially offset from one another. The incisions are preferably formed in the zone L of the pole which is to be adjacent ground level. For the incising operation, the pole is moved into position on supports 16 of a jabbing machine having upper and lower sets of blades 4, each blade being mounted in a block 4 advanceable along a guide rod 9 by a hydraulic piston and cylinder unit 8 to make an incision. Each set comprises twelve blades arranged for the production of a pattern of incisions as shown in Fig. 2. The actuation of the sets of blades to jab the pole is alternated with a stepwise rotation of the pole by a chain 18 until the full circumference has been perforated according to a programme wherein the number of incisions required is preselected by a counter according to the circumference of the pole. The pole is then ejected from the machine. The sequence of operations is controlled by time switches, and the rotation of the pole by a switching arrangement including a photoelectric sensing device. The dimensions of the knives and the spacing of the holes are specified. The pole may be a mast or a fence post. The impregnation with water soluble salts is effected in an autoclave. (For Figures see next page.) |
