Improvements in agricultural and like machinery

摘要

663,192. Sawing. MARPLES & SON, Ltd., R. M., and MARPLES, S. A. Dec. 2, 1949 [Dec. 3, 1948], No. 31351/48. Class 145 (ii) [Also in Group I] Hedge-cutting and crop-cutting machinery is provided with reciprocating or rotating cutters supplied with compressed gas in which is suspended a fine mist of oil to lubricate and simultaneously clean the cutting mechanisms. Compressed air with oil in suspension is brought through a flexible hose 1 to a tap 2 and thence through a hollow handle 3 to a reciprocating air motor described in Specification 663,259, [Group XXIX]. The motor, which is attached to the handle by a screwed ring 4, comprises a piston 5 fitted with rings 6 and slidable in a cylinder liner 7 in a tubular housing 8a. The oil-impregnated air passes by means of a sleeve valve alternately to chambers 9, 10 at each end of the piston thereby reciprocating the piston and its connecting rod 11 to drive the cutter blade 12. The forward air chamber 10 is closed by a disc 13 fitted with a bearing 15 for the connecting rod and the rear chamber 9 is similarly closed. The housing 8a is extended to form a housing for the blade 12. This extension has a flattened portion 8b-8c forming a duct 16 and slot 17 for the blade Fig. 2 (not shown). The leading edge 18 of the extension is notched to form teeth 20 coacting with the blade 12. In the opposite edge of the extension, notches 21 may be formed exposing blade teeth 23 suitable for cutting thick woody growths. The blade is slotted to accommodate guide screws 24, 25. Oil from the compressed air condenses in the moving surfaces of the motor to lubricate them, exhaust air and oil escaping into a cavity 27 and along the duct 16 and finally passes to the atmosphere between the blade 12 and the teeth 20, simultaneously removing dust, grass, sawdust and the like from the cutting edges, while leaving a film of oil on the contacting surfaces. Sealing material 28, 29 may be used to close alternative exits for the air. In an alternative construction a circular cutter disc driven by a rotary air motor is mounted on a vehicle, the motor being adjustable on a supporting arm to vary the position of the disc. Compressed oil-impregnated air is fed to the motor and passes to the atmosphere through vents in the motor casing. Oil from the extruded air impinges on the disc and after condensation flows over the disc to the cutting edges. Holes may be drilled through the disc to allow the oil to pass to the remote surface.