GB2083736A - Improvements in and relating to mowers - Google Patents

Abstract

A mower having a housing which supports at least two blades, each blade being mounted for rotation about one of at least two vertically disposed axes located on a line perpendicular to the line of travel of the mower so that the blades are adapted to sweep out side by side horizontally disposed circles, the mower being characterised in that one blade (55) is disposed relative to the other blade (36) so that the two circles overlap. <IMAGE>

Description

SPECIFICATION Improvements in and relating to mowers The present invention relates to mowers for cutting grass.

One known type of mower comprises a housing supporting two vertically depending shafts, each of which has rigidly attached to its lower end an elongate horizontally disposed blade. The mower is pulled behind a tractor with the shafts disposed side by side transversely of the line of travel of the tractor. The shafts are driven from the tractor power take-off shaft, causing the blades to rotate, each blade sweeping out a circle. The blades are coplanar, but are mutually separated with the result that a small clearance or gap is left between the circles.

A disadvantage of the known type of mower is that in operation, a narrow swath is left uncut.

One proposal to overcome the disadvantage involves disposing the blades in echelon, for example by adding a third blade located behind the first two blades, to cut the line of swath.

A second proposal involves arranging the blades so as to overlap the swept circles, and driving the blades synchronously so that they do not contact one another. The second proposal is described in British Patent Specification No. 1,119,641.

Athird proposal involves the positioning of a vertical planar screen in the housing so that the screen projects into the gap between the two swept circles and divides the swath pushing it to one side or the other, so that the swath is cut by one or other of the blades. The third proposal is described in British Patent Specification No. 1,212,352.

According to the present invention, there is provided a mower comprising a housing which supports at least two blades, each blade being mounted for rotation about one of at least two vertically disposed axes located on a line perpendicular to the line of travel of the mower so that the blades are adapted to sweep out side by side horizontally disposed circles, the mower being characterised in that one blade is disposed relative to the other so that the two circles overlap.

In one preferred construction according to the invention, one of the circles is swept out by a first elongated generally rectangular blade centrally supported on a shaft defining one of said axes, and the other blade is supported on and above a second such elongated blade centrally supported on a second shaft defining the other of said axes, the two elongated blades being adapted to sweep out coplanar side by side circles which are spaced apart, the said other blade projecting across the gap between the two elongated blades to sweep out a circle which overlaps the circle swept out by the first elongated blade.

Advantageously, said other blade is an auxiliary blade which is bolted or otherwise secured to and above one extremity of the first elongated blade, and a second auxiliary blade is provided on the other extremity of the first rectangular blade.

The housing may support more than two such elongated blades, all of which are located in the same plane and on a line perpendicular to the line of travel of the cutter, alternate rectangular blades being provided with one or two such auxiliary blades, each end of each elongated blade being generallyE-shaped, the lower limbs of the ~ -shaped ends being co-planar.

In a second preferred construction according to the invention each blade is mounted upon the periphery of a circular member supported upon the lower end of one of two spaced apart vertically disposed shafts, each blade being generally ~ -shaped and being mounted so that the lower limbs of the-blades overlap and sweep out overlapping circles when the circular members are rotated. Each of the circular members supports two or more identical blades.

The housing may support two or more such circular members, all being located in the same plane and on a line perpendicular to the line of travel of the mower, alternate circular members supporting identicalE-shaped blades.

The invention will hereinafter be described more particularly with reference to the accompanying drawings which illustrate, by way of example, preferred embodiments of the invention.

In the drawings, Figure 1 is a front sectional elevation of one embodiment of a mower according to the invention, Figure 2 is an enlarged view of a detail of Figure 1, Figure 3 is a sectional plan on lines Ill-Ill of Figure 2, Figure 4 is a front sectional elevation of a second embodiment of a mower according to the invention, and Figure 5 is a sectional plan on lines V-V of Figure 4.

Referring to the drawings, and initially to Figures 1 to 3 inclusive, the mower comprises a housing 12 adapted to be mounted upon and to be supported from the three point linkage of a tractor (not shown).

Mounted upon the housing 12 is a gear box 13 which is adapted to be connected to the power take-off of the tractor. Operatively connected to the gear mechanism (now shown) in gear box 13 is one end of a central drive shaft 15, on the other end of which is secured an elongated generally rectanular blade 16. The drive shaft 15 is rotatable in and is further supported by a bearing 17 mounted upon a plate 22 bridging the side walls 21 of the housing 12.

Located at one end of the housing 12, and rotatable in a bearing 23 mounted internally of the housing is the upper end of a driven shaft 25, the lower end of which supports an elongated generally rectangular blade 26. Intermediate the ends of the driven shaft 25 is a support bearing 27 also mounted on the plate 22. Located at the other end of the housing 12 is a driven shaft 35 which supports an elongated generally rectangular blade 36. The shaft 22 is supported in bearings 33 and 37, which are identical to bearings 23 and 27 respectively. The blades 16,26 and 36 are all identical.

On the drive shaft 15 are rigidly mounted a pair of drive pulleys 18 and 19, each of which has a V-shaped groove. The drive pulley 18 is connected by way of a V-shaped belt 52 to a driven pulley 28 rigidly mounted on the driven shaft 25, and the drive pulley 19 is connected by a belt 53 to a driven pulley 38 rigidly connected on the drive shaft 35. Each end of the generally rectangular blades 16,26 and 35 x -shaped. On each extremity of the central blade 15 is connected an auxiliary blade 55, the latter being connected to the blade 15 by means of a bolt 56, nut 57 and spacer 58. The auxiliary blade 55 is thus readily replacable.

The auxiliary blade 55 projects over the gap left between the central blade 16 and each of the outer blades 26 and 36. For the purposes of illustration, each of the blades 16,26 and 36 are shown in line in Figures 1 and 2 of the accompanying drawings. The circles swept out by the blades 16, 26, 36 and 55 are shown in Figure 3 of the drawings.

It will be appreciated that in operation the swath uncut by blades 16,26 and 36 would be cut by the auxiliary blade 55.

Referring to Figures 4 and 5 of the accompanying drawings, the mower comprises a housing 62 adapted to be mounted upon and to be supported by the three point linkage of a tractor (now shown).

Mounted upon the housing 62 is a gear box 63.

Operatively connected to the gear mechanism (not shown) in gear box 63 is one end of a drive shaft 65, the other end of which extends through bearing 67 mounter on the underside 68 of the housing 62.

The housing 62 also supports a driven shaft 75, one end of which is rotatable within a bearing 73 mounted internally of the housing: the other end of the driven shaft 75 extends through a bearing 77 mounted on the underside 68 of the housing 62.

On the lower end of the drive shaft 65 is a circular plate 82 to which is connected three~-shaped blades 83. Each blade 83 is connected to the plate 82 by means of a bolt 84 and a nut 85, the bolt 84 passing through the metal plate 82.

At the lower end of the driven shaft 75 is connected a circular plate 92, to which is connected three-shaped blades 93, each of the blades 93 being connected to the plate 92 by a bolt 94 which passes through the plate 92, and by a nut 95.

The drive shaft 65 has rigidly mounted thereon a drive pulley 86, and the driven shaft 75 supports a driven pulley 96. A belt 87 connects together the two pulleys 86 and 96.

One of the blades 83 is bolted to the circular member 82 on a radius B which is greater than the radius A at which all of the other blades 83 and 93 are bolted to the circular members 82 and 92 respectively. The bolt 84 which secures blade 83 at radius B, is longer than the other bolts 84 and longer than bolts 94 and a spacer 102 is located on the longer bolt 84 between the blade 83 and the circular member 82, so that the blade 83 at radius B sweeps out a circular which overlaps that swept out by blades 93.

The mower shown in Figures 1 and 4 have skids 104 and 106 respectively.

Claims (11)

1. A mower comprising a housing which supports at least two blades, each blade being mounted for rotation about one of at least two vertically disposed axes located on a line perpendicular to the line of travel of the mower so that the blades are adapted to sweep out side by side horizontally, disposed circles, the mower being characterised in that one blade is disposed relative to the other so that the two circles overlap.

2. A mower as claimed in Claim 1, characterised in that one of the circles is swept out by a first elongated generally rectangular blade centrally sup ported on a shaft defining one of said axes, and the other blade is supported on and above a second such elongated blade centrally supported on a second shaft defining the other of said axes, the two elongated blades being adapted to sweep out co planar side by side circles which are spaced apart, the said other blade projecting across the gap between the two elongated blades to sweep out a circle which overlaps the circle swept out by the first elongated blade.

3. A mower as claimed in Claim 2, characterised in that said other blade is an auxiliary blade which is bolted or otherwise secured to and above one extremity of the first elongated blade.

4. A mower as claimed in Claim 3, characterised by the provision of a second auxiliary blade on the other extremity of the first elongated blade.

5. A mower as claimed in any one of Claims 2, 3 or 4, characterised in the provision of more than two such elongated blades, all of which are located in the same plane and on a line perpendicular to the line of travel of the mower, alternate rectangular blades being provided with one ortwo such auxiliary blades.

6. A mower as claimed in anyone of Claims 2 to 5, characterised in that each end of each elongated blade is generally-shaped, the lower limbs of the -shaped ends being co-planar.

7. A mower as claimed in Claim 1, characterised in that each blade is mounted upon the periphery of a circular member supported upon the lower end of one of two spaced apartverticaly disposed shafts, each blade being generally-shaped and being mounted so that the lower limbs of theLblades overlap and sweep out overlapping circles when the circular members are rotated.

8. A mower as claimed in Claim 7, characterised in that each of the circular members supports two or more identical blades.

9. A mower as claimed in either of Claims 7 or 8, characterised in that the housing supports two or more such circular members, all being locatedin the same plane and on a line perpendicular to the line of travel of the mower, alternate circular members supporting identical-shaped blades.

10. A mower generally as hereinbefore de scribed with reference to, and as illustrated, in Figures 1,2 and 3 of the accompanying drawings.

11. A mower generally as hereinbefore de scribed with reference to, and as illustrated in, Figures 4 and 5 of the accompanying drawings.