A Motor Roller for £45
Page 65
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AMOTOR roller costing about £45 is an attractive proposition to anyone who possesses a lawn no larger than a tennis court, and when more spacious grounds have to be rolled it is uneconomic to use man-power. A new roller, the product of Motor Units, Ltd.—a subsidiary of Singer and Co., Ltd., Coventry—has recently been marketed and is to be sold at the price mentioned above, complete even to the provision of tools.
The design of the machine incorporates many ingenious features, such as a control for friction clutches giving ahead and astern drives with a neutral position, a device to avoid skidding one rear roll when negotiating a turn and brakes to both rear rolls. As will be seen from the accompanying illustrations the machine is built up of castings of ample. size for the work they have to perform, such a construction helping to provide the necessary weight without apparent clumsiness of design ; the roller actually scales 10 cwt., without the operator. The diameter of the front rolls is 91 ins, and the width 1 ft. 41 ins., whilst the main rolls are 1 ft. pi ins, diameter and 1 ft. 11 ins. wide. Without cramping the drive, it has been possible to keep the overall length within 5 ft., the overall width being only 2 ft. 6 ins.
A main chassis, frame is employed, with suitable cross-members for bracing purposes. At the front, a swivel is provided for steering and an ingenious differential arrangement is employed to avoid skidding the rear rolls when making a sharp turn. It will be realized that if the drive be taken on both sections of the roll skidding must occur on a turn, or, if a constant drive to one half of the rear roll only be employed then the machine is limited to turning in one direction. •
In this Motor Units product, a system of levers and io a cam are so arranged that immediately an attempt is made to turn the roller, the cam, which is mounted on the steering column, strikes one of two side levers connected to spring-loaded dog '...-lutches on the countershaft, throwing out the dog clutch driving the roll on the inside of the turn. By this means the drive is taken entirely from the outer half of the roll and any skidding or slip is avoided.
As we have already mentioned, the dog clutches are spring-loaded and so soon as the steering is returned aa the straight-ahead. position the clutch
j amps back into engagement and the drive is taken equally upon both rear rolls. With this arrangement a turning circle of 12-ft. diameter in either the left or right-hand direction is obtainable.
The power is provided by a Villiers 250 c.c. two-stroke, aircooled engine with a flywheel magneto and a Villiers carburetter. Lubrication is carried out on the petroil system, and is, of course automatic. Fuel is fad to the c.arburetter from a gravity tank having a capacity of one gallon of petroil mixture which is sufficient for approximately four hours' rolling. The primary drive is by chain to a friction pulley, which is in definite and constant engagement with a similar pulley of the same size. These two pulleys are mounted on a bracket over a third pulley, which can be rocked in order to bring it into engarment with either of the upper pulleys. A hand control, accessible to the driver, is fitted, and when pushed forward 'engages the front upper pulley and the lower pulley and drives ahead;
reverse is obtained by rocking the pulley backwards and engaging the rear upper pulley with the lower pulley. Final drive from the countershaft is conveyed to the rear rolls by chains.
If required, a trailer specially made to house the motor roller may be obtained. It is of moderate size and of sturdy construction so that the whole outfit may be towed by an ordinary 1Cr h.p. car. The trailer costs £25 and the roller may be run on to, it Under its own power.