GB784087A - Improvements in or relating to tractor mowers - Google Patents

Abstract

784,087. Mowing machines. PYRAMID MACHINES, Ltd. Dec. 7, 1955 [Dec. 7, 1954], No. 35395/54. Class 6(3). A tractor-borne and tractor-driven mower comprises a frame 2, carried on the draughtlinks 3, 4 so as to be movable vertically thereby and to be movable transversely with respect thereto, the cutting mechanism 21 being mounted on the frame so as to be swingable in a vertical plane and also to be capable of slewing horizontally under overload, the cutting mechanism being driven through flexible hoses 39, 40 from the tractor hydraulic system. The frame 2 comprises transverse parallel bars 5 joined by braces 6, three of which are provided with means of attachment to the draught-links and are apertured and split vertically to permit the remainder of the frame to slide transversely, locking bolts being provided to locate the frame in an adjusted position, The frame terminates in a vertical sleeve 12 in which the remainder of the mower can swing to relieve excess rearward pressure on the cutter bar which is normally held in position by a spring-loaded bolt 31 engaging in a notch in a quadrant 14. The quadrant 14 forms part of a supporting- frame 15 which includes sleeves 16 in which rods 17 slide, the rods 17 carrying a bracket 19 and being floatingly suspended in the frame 15 through a compression-spring 19. The cutterbar 21 is mounted on a shoe 20 pivoted to the bracket 19 about a horizontal longitudinal axis. A rotary hydraulic motor 38 drives the cutter through a crank-disc 58 and pitman 59, Fig. 9, the pitman being ball-jointed to a bell-crank 60, the other limb of which is connected through a link, Fig. 12, to the knife-bar 57. The supply and return conduits 39, 40 of the hydraulic transmission pass through a control valve 43, Fig. 14, having two by-pass passages 46, 47, controlled by valves. The valve in one passage 46 is an adjustable spring-loaded relief valve 48, 49, 50 which opens at a pre-determined pressure, but the other valve 52 is a throttle which controls the speed of the hydraulic motor by venting supply-fluid through the return-conduit 40. The link 63, Fig. 12, is split longitudinally and has a cam-lever 69 and bolt 67 to clamp the halves together.