GB2298775A

GB2298775A - Grass cuttings collection

Info

Publication number: GB2298775A
Application number: GB9508038A
Authority: GB
Inventors: Miles Roland William Bozeat
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-03-16
Filing date: 1995-04-20
Publication date: 1996-09-18
Anticipated expiration: 2015-04-20
Also published as: GB9508038D0; GB2298775B; GB9505345D0

Abstract

A lawnmower has a bifurcated radial fan 1 providing an air cushion flow 21 (for this embodiment) and a flow 2 for collection of grass cuttings. The collection flow takes entrained cuttings up a duct 7 and into a collection chamber 12 where the cuttings are separated from the air flow by centrifugal forces as the air circulates in the chamber. The air is recirculated via return duct 13. Fig shows a wheel embodiment having no air cushion flow.

Description

IMPROVED GRASS CUTTING AND COLLECTING MACHINE This invention relates to a machine for collecting grass cuttings cut by a rotating blade.

Various systems have been devised to collect grass cut by lawn mowers utilizing a rotating blade whether supported on wheels, "Rotary mowers" or via a cushion of air, "Hovermowers".

Existing cut grass collection systems are generally deficient in one or more areas amongst which may be numbered: 1 - The collecting efficiency is reduced due to the fouling, by cut grass, of the various meshes and grilles which are used to allow the flow of air out of the collecting boxes.

2 - As the air pressure is not equally distributed around the perimeter, air cushion platforms - "Hovermowers" are intolerant of the asymmetrical loads created by the accumulating weight of cut grass collected, consequently the machines "tip" and drag along the ground.

3 - Existing cut grass collection systems do not continuously circulate thus some cut grass or associated detritus can escape the systems and so discharge unwelcome waste.

4 - The meshes and grills used to block the flow of cut grass are inherently messy, dirty and difficult to clean.

5 - the configurations of currently available mowers are space inefficient and cumbersome.

6 - Existing hover mower cut grass collection systems pick up cut grass left in the wake of the machines and only when the machines are driven in straight lines.

7.- Existing mower systems dictate that the machines must be driven in one direction to be effective.

It is to the above deficiencies this invention provides a solution.

According to the present invention there is provided a grass cutting machine comprising a means for creating and utilizing a continously circulating air flow to groom uncut grass before cutting by a rotating knife before carrying cut grass into the top of demountable grass collecting boxes via a duct where the cut grass is separated from the airflow as it circumnavigates a structure mounted within the grass collecting boxes. The airflow free of grass leaves from the top of the grass collecting boxes via a second duct and thence into the source of the airflow, preferably a radial flow fan. The present invention may be mounted on an air lubricated or wheeled platform.

A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which: Fig 1/2 is a "transparent" perspective diagram Fig 2/2 is a "transparent" side elevation In all drawings only those elements essential to the operation of the invention are illustrated. Handles, wiring, power sources and control gear have been deleted for clarity.

Referring to the drawings the improved grass cutting and collecting machine comprises a radial flow fan 1 driven by a rotational power source 17. An airflow 2 is drawn axially through fan inlet 3 into the radial flow fan 1. Airflow 2 is accelerated by the rotational action, anticlockwise in this example, of the radial flow fan 1. Airflow 2 is expelled axially from radial flow fan 1 through a continuous fan outlet 4 around the base perimeter of radial flow fan 1. The tendency for airflow 2 to travel downwards beyond fan outlet 4 is modified by the tangential velocity inherent within airflow 2 and the proximity of the ground datum 5 such that airflow 2 travels radially towards the perimeter of cutting chamber 6. Airflow 2 circulates upwards and out of the cutting chamber 6 via vertical duct 7.The movement of airflow 2 within the confines of cutting chamber 6 tends to groom uncut grass 9 bringing it into the way of rotating knife 8. Once cut by the rotating knife 8 cut grass 18 joins airflow 2. Airflow 2 carrying cutgrass 18 exits the vertical duct 7 at orifice 10 which said orifice 10 is positioned at the uppermost section of vertical duct 7. Airflow 2 travels around separator tower 11. As a factor of the tendency for all material to leave a rotational path at a tangent the cut grass 18 becomes separated from airflow 2. The cut grass 18 so separated is deposited in the grass collection boxes 12. Grass collecting boxes 12 are demountably attached to the machine by toggles catches or similar.

Airflow 2 having circumnavigated the separator tower 11 enters the vertical duct 13 at orifice 14 which said orifice 14 is positioned at the upper most section of vertical duct 13. Airflow 2 is directed into the radial flow fan 1 through fan inlet 3 via port 15 to which said port 15 vertical duct 14 is airtightly joined at orifice 16.

Orifice 16 is positioned in the lower section of the vertical duct 14.

At the interface of port 15 with fan inlet 3 there subsists means 22 for substantially restricting airflow 2 from leaving the confines of port 15 and radial flow fan 1. The construction and assembly of vertical duct 7 and vertical duct 13 is such that they locally provide locally an airtight barrier between the two grass collection boxes 12, the separator tower 11 and grass cutting chamber 6. Grass collecting boxes 12 are closed on all sides except at their interface 19 with each other and with the separator tower 11. The interface 19 between grass collecting boxes 12 and the interface between grass collecting boxes 12 and the separator tower 11 are rendered airtight during operation of the machine.

Figure 1/2 demonstrates an embodiment of the improved grass cutting and collecting machine wherein the improved grass cutting and collecting machine is mounted upon a wheeled chassis 20 which chassis 20 holds the improved grass cutting and collection machine above the ground datum 5 at a point suitable for the cutting of uncut grass 9.

Figure 2/2 illustrates an embodiment of the improved grass cutting and collecting machine where the said machine is suspended above ground datum 5 by the action of air lubrication created by airflow 21 so providing a hover platform. In this said embodiment, radial flow fan 1 is axially and laterally bifurcated such that airflow 2 and airflow 21 are simultaneously and discretely created. Airflow 21 is drawn by radial flow fan 1 from outside the confines of the machine and down the inner confines of separator tower 11. Airflow 21 is expelled radially from radial flow fan 1 and into a cavity 23 formed around cutting chamber 6 and beneath grass collection boxes 12. Airflow 21 is expelled from beneath the machine between grass collection boxes 12 and ground datum 5 so providing hovering air lubrication.

Claims

CLAIM 1

An improved grass cutting and collection machine wherein there subsists means to create a continuously circulating airflow preferably by a radial flow fan the said airflow being directed towards ground datum and thence upwards into a cutting camber whereupon the said airflow collects grass cut by blades housed within the said cutting chamber and via a duct leaving the said cutting chamber and thence via a port exiting said duct which port is positioned at a highest practical point within the confines of the volumetric area contained by the demountable grass collecting box or boxes thence via circumnavigation of a structure positioned within the volumetric confines of the said collecting box or boxes so to separate the said cut grass tangentially from the said airflow and to deposit the said cut grass in the said grass collecting box or boxes thence via a second port positioned at the highest practical point upon a second duct which duct is housed within the volumetric confines of the said cut grass collecting box or boxes thence via the said second duct to the said means wherein the said low air flow is created.

CLAIM 2 A machine as claimed in claim 1 wherein the machine is supported above the ground datum by virtue of a wheeled chassis.

CLAIM 3 A machine as claimed in claim 1 wherein the machine is supported above the ground datum by virtue of air lubrication in a hover.

CLAIM 4 A machine as claimed in any of claims 1, 2 or 3 wherein the grass grooming and carrying airflow is discharged axially towards ground datum.

CLAIM 5 A machine as claimed in claim 1 and claim 3 wherein the grass grooming and carrying and the air lubrication airflows are simultaneously and discretely created within and by an axially and laterally bifurcated radial flow fan.