GB878213A - Improvements in high-speed mowers - Google Patents

Abstract

878,213. Mowing machines ; hedge-cutters. FREEBORN, J. E., CHAPMAN, R. H., and MARR, W. F. Sept. 27, 1957 [Oct. 3, 1956], No. 30159/56. Classes 6(2) and 6(3). A mowing machine has two knife-bars reciprocated in opposite directions and forming a closed oscillatory system with the driving means and with a resilient device connected to the two knife-bars to store the maximum kinetic energy generated during reciprocation. The mower is mounted between the front and rear wheels of a tractor 10 and is driven from the lateral power take-off 11 through an eccentric 12 and connecting rod 13. The rod 13 reciprocates a shaft 14 longitudinally, the shaft being mounted in bearings 15, 16 and carrying a member 18 pivoted to a link 19. The link is coupled to a pair of parallel tubes 24, 25 so that its reciprocation twists the tubes about their axes, the tubes being secured at their lower ends both to internal torsion rods 30, 31 (which are anchored at their top ends) and to an arrangement including a link 34 symmetrically disposed relatively to the ink 19, whereby the link 34 receives the drive rom the shaft 14, via the link 19 and the orsion tubes. The link 34 is connected to two bell-cranks 36, 37 by a rod 35, each bellcrank being connected to one of the superimposed knife-bars 46, 47. The knife-bars are not identical, the upper bar having squarecut teeth 54 and the lower having triangular teeth 53, both bars being reinforced by riveting to flat bars such as 52. A mower-bar 48 forms a bed-plate on which the knife-bars rest, the mower-bar having forward portions 55 which carry pointed guards or fingers 56 embracing the knife-bar teeth but not serving any cutting function. The outer ends of the knife-bars are attached to levers 57, 58 pivoted at 59 on the mower-bar structure 48 and connected to a torsion-bar and tube 65, 66 so that the knifebars are maintined in constant tension by the torsion devices 65, 66 and 24, 25, the tension being Adjustable by rotation of the pivot 59 which is eccentric. The frame 28 which carries the tubes 24, 25 is pivoted to lugs 29 on a mounting plate 17 on the tractor, the pivotaxis being co-incident with a pivot between the link 19 and the member 18, so that the frame may be inclined at any angle without interrupting the drive. The mower-bar 48 is similarly pivoted to the lower end of the frame 28, whereby the cutters may be inclined at any angle or even elevated to the upper position in Fig. 16, for cutting hedges, an adjustable stay 49 being provided between the frame 28 and plate 17. Specifications 878,212 and 878,214 are referred to.