The first pedal powered lawnmower
Introducing Grazor, the pedal powered mower, which offers a brand new approach to getting the perfect cut.
Designed by the team at design and innovation agency, Seymourpowell, Grazor is a self-powered ride-on lawnmower that not only cuts the lawn, but also allows the user to improve their health with some useful aerobic exercise.
How does it work?
Grazor uses the well-proven ergonomics from a recumbent bicycle and combines it with a front mounted cylinder mower for the perfect cut.
The cutting reel itself is a new construction, with aluminium 'spiders' acting as the framework for flexible steel blades (not unlike larger versions of the blades of a modern razor). These steel blades are made flat, for low cost and ease of construction, and only take up their helical shape when they are mounted to the aluminium spiders by quick release rivets. The blades cut in the normal way by rotating past a fixed blade at the bottom, where the two combine to work like a pair of scissors.
The reel assembly can be lifted up and down via the blue handle between the drivers legs. This allows the driver to pick up the cutting reel to drive easily between his lawns and his garage or shed, for example when reversing or maneuvering. It can also slide from left to right to allow the user to decide whether to cut via the left hand or right hand edge.
Cutting height is adjusted by the height of the rollers at the back of the reel assembly.
Cut grass is ejected out of the back, rather than being projected out of the front - this takes less energy because it does not add precut grass to the grass to be cut.
Drive system
Drive is taken from the front mounted pedals down to a five speed hub type gear box - depending on the terrain, most users will tend to use just one or two gears during the course of cutting their lawn. Most of the time, the freewheel function is disconnected, to enable pedaling backwards to reverse, but it can be re-engaged to allow down hill coasting if the terrain allows.
From the gearbox, the drive is taken down, via another chain, to a differential between the front wheels - as in any vehicle, a differential is needed to allow the inside wheel to travel slower than the outside wheel when turning. The chain drive to the cutting reel is taken off the right hand wheel axle.
Many traditional push mowers translate the energy applied by the user pushing, to the cutting reel via the ground, where the wheels are turned by their interaction with the ground. And this in turn spins the cutting reel. The trouble is that this is very inefficient in a ride-on mower, with significant power loss caused by the variable of the friction in the ground. By maintaining a direct drive connection between pedal and reel, and pedal and wheels, mechanical losses can be limited.
The wheels themselves are broad, for traction (on damp grass for example), yet very light. The front drive system does not have to accommodate the steering as well, which would add weight and complexity. Steering is now done by the rear wheel - this emulates much larger golf course type cylinder mowers, where the rear wheel steering offers great maneuverability and precision.
The steering bar pivots on the central chassis, providing the user with two grips adjacent to his/her hips. One grip has the gear shift and the other has the freewheel on/off control.
Chassis
The chassis is a super lightweight carbon composite construction which provides all of the mounting points for the various components. The seat, which is also a carbon composite, has thermoformed seat and back pads, which are of an encapsulated foam sandwich construction to better support the body. Both seat and handlebars can be adjusted back and forth to suit the users height.