GB653202A - Improvements in lawn mowers - Google Patents

Abstract

653,202. Lawn-mowers. RANSOMES, SIMS & JEFFERIES, Ltd., and PLUMB, A. B. Sept. 6, 1948, No. 23448. [Class 6(ii)] A lawn-mower has a rear framework carrying the cutting mechanism and provided with a ground roller and a front framework mounted on side wheels, the two frameworks being pivotally connected and relatively adjustable to regulate the height of cut by means of a handoperated spindle rotating in the rear framework and engaging a nut in the front framework. Fig. 1 shows a mower in which each side frame is in two parts 1, 2. The side parts 1, 1 are rigidly connected by a cross-stay 3 to form a rear framework carrying the axle 4 of a ground roller 5, the shaft 14 of a cutting cylinder 6 and a bottom blade 7. The side plates 2, 2 are rigidly connected to a tubular cross-stay 8 to form a front framework provided with ground or side-wheels 9, 9. The two frameworks are pivotally connected, bosses 10, 10 on the side plates 2, 2, Fig. 2, being mounted to oscillate on extentions of bosses 12, 12 on the side plates 1, 1. The bosses 12, 12 form housings for ballbearings for the shaft of the cutting cylinder. The side plates 2, 2 have bosses 15 fitted with bearing bushes 16, 16 for the stud axles 17, 17 of the side wheels. The side wheels have spur gears 18, 18 driving pinions 19, 19 on the shaft 14. Mounted to rotate in a swivel 23 on the cross-stay 3 is a screw 20 engaging in a cylindrical nut 26 mounted to swivel in the cross-stay 8. To adjust the height of cut, the screw 20 is adjusted by rotating the handle 21. This rotation produces relative movement between the front and rear frameworks, the rear framework pivoting about the ground roller so that the cutting cylinder and the bottom blade are raised or lowered according to the direction of rotation. The bottom blade 7 is mounted on a carrier 27 having end bosses 28 oscillating on the roller axle. The blade 7 is adjustably held relative to the cutting cylinder by spring-loaded bolts 32 passing through the carrier 27 and a web 33 of each side plate 1. Upward movement of the bottom plate is limited by stop screws 29. When the lawn-mower or the cutter-mechanism is motor-driven each side frame is in one piece pivotally mounted on the axle of the ground roller, while supported forwardly on an axle having cranks for the stub axles of the side wheels. A cross-stay rigidly connects the side plates and carries spaced brackets supporting the motor. The height-adjusting screw is held between crank arms on the forward axle and passes through a bar carried by the brackets. Rotation of the screw moves the crank arms to swing the forward axle about the stub axles of the side wheels and thus raise or lower the side plates and hence the cutting-mechanism.