GB2392076A

GB2392076A - Cut grass collection means - shared duct

Info

Publication number: GB2392076A
Application number: GB0219366A
Authority: GB
Inventors: Miles Roland William Bozeat
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-08-20
Filing date: 2002-08-20
Publication date: 2004-02-25
Also published as: GB0219366D0

Abstract

A rotary cut grass collecting mower is equipped with a duct 11 between the cutting chamber 1 and the collecting box 7 so arranged as to allow an airstream 4 carrying cut grass to enter the collecting box and simultaneously allow a back pressure relieving airstream 8 free of grass cuttings to leave the grass collecting box.

Description

-1 CUT GR\SS COLLECTION IIEANS - SHARED DUCT

This invention relates to a grass collecting rotary mower.

Grass collecting rotary mowers are well known devices wherein a rotating cutting blade is swung within a walled cutting chamber as the mower is propelled over the grass to be cut. The resultant cut grass leaves the cutting chamber at a tangent borne on an air stream generated by the swinging blade, through a duct thence into a collecting box where the cut grass is deposited.

A means of reliving the back pressure generated by the incoming air stream must be devised in order for the machine to function this is normally achieved by constructing the grass box from an air permeable material or by a second duct leaving the collecting box.

According to the present invention there is provided a duct between the cutting chamber and the collecting box so arranged as to allow an air stream carrying cut grass to enter the collecting box and simultaneously allow a back pressure relieving airstream free of grass cuttings to leave the grass collecting box.

A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which: Figure 1 shows in transparent perspective, the invention in operation. The drive system, control gear and chassis have been omitted for clarity.

Figure 2 shows in elevation, the invention in operation. The drive system, control gear and chassis have been omitted for clarity.

-2 Referring to the drawings the invention comprises a cutting chamber l wherein rotates a cutting blade 2 which said cutting blade is provided with an angled face 3 [ as in a propeller] the said angled face 3 imparts an upward component to the high speed air stream 4 upon which high speed air stream are borne cut grass clippings 5 the said high speed air stream 4 is vectored and diverted from and through the upper surface of the said cutting chamber I into and through the combined inlet and return duct 6 which said combined inlet and return duct engages with the air impermeable cut grass collecting box 7 the said high speed air stream 4 enters the said air impermeable cut grass collecting box 7 at the highest practical point the said grass clippings 5 leave the said high speed air stream 4 as a factor of gravity and or the diminishing velocity of the said high speed air stream and or impact with the rear face of the said air impermeable cut grass collecting box 7 consequently the said grass clippings 5 are deposited within the said air impermeable cut grass collecting box 7 the said high speed air stream 4 dissipates within the said air impermeable cut grass collecting box 7 within the said collecting box the air then reforms as air stream 8 free of grass clippings 5 said air stream 8 leaves the said air impermeable cut grass collecting box 7 through the said combined inlet and return duct 6 as a factor of being propelled by the back pressure within the said air impermeable cut grass collecting box 7 and being drawn out as a factor of an air stream 9 which said air stream 9 exists within the cutting chamber I as a factor of having been generated by variously a hover fan [ not illustrated] and or a blower assist fan [ not illustrated] and or the said cutter blade 2 passing the leading edge 10 of the base of the said combined inlet and return duct 6. Assistance to the said high speed air stream 4 to attach itself to the upper face l l of the said combined inlet and return duct 6 may be rendered by the cony guration of the said upper face 1 1 to include an area of low pressure 12 [ Figure 2 only].

Claims

-3 CLAIMS

1. A means by which the back pressure generated by air entering an air impermeable cut grass collecting box of a rotary mower is relieved by the use of a combined inlet and outlet duct set between the said air impermeable cut grass collecting box and the cutting chamber of the said rotary mower to allow the exit passage of a pressure relieving air stream from the said air impermeable cut grass collecting box.

2. A claim as in claim 1 where the said means are an integral part of a hover mower.

3. A claim as in claim 1 where the said means are an integral part of a wheeled mower.

4. A claim as in claims I, 2, and 3 where the combined inlet and outlet duct is configured so as to enhance the attachment of the air stream entering the cut grass collecting box to the top of the said duct.