GB2174585A - Supporting gang mower cutting units - Google Patents

Abstract

This invention relates to a gang mower and in particular for mowers for use on undulating ground. The mower is constituted by a power trailer having an array of staggered mower units 20 to 24 (Fig. 1, not shown). Each mower unit is belt driven and is connected to the trailer at one end by means of a link 30. The link 30 is mounted on the trailer and the respective mower unit by means of respective shafts 32 and 39 which allow articulation about horizontal forward and aft axis. A spring 35 surrounds the shaft 32 and acts between the trailer and the link 30 in a sense to urge it rearwardly to maintain drive belt tension. The shaft 39 is carried by a sleeve 45 having a swivelling stem 46 which allows the mower unit to rotate about a transverse horizontal axis with respect to the link 30. The mower unit is thus able to follow the contours of the ground. <IMAGE>

Description

SPECIFICATION Gang mower This invention relates to a gang mower as used for mowing large areas of ground such as golf courses, sports grounds or other large grassed areas.

In existing designs of gang mower, the mower units do not satisfactorily conform to the contour of the ground so that cutting is not as efficient and elegant as desired. There are also problems with the drive of such mower units. In one type the mower units are driven by individual hydraulic motors supplied with pressure fluid from a central hydraulic pump. This arrangement tends to be very expensive to manufacture and to maintain. In another type each of the mower units is individually movable relative to the main gang trailer frame and is driven by a flexible belt which commonly breaks. Accordingiy it is an object of the invention to provide an improved gang mower which will solve at least some of the existing problems and limitations.

From one aspect the invention consists in a gang mower comprising a main frame connected to a number of individual mower units, and including drive means for the individual mower units, each of the units being connected to the frame at one end by means of an articulated joint which includes a swivel bearing permitting movement of each mower unit about a generally horizontal transverse swivelling axis.

Preferably each mower unit has ground rollers or wheels positioned both in front of and behind the swivel axis, to allow the unit to follow the ground contour. According to another preferred feature of the invention each articulated connection includes a double articulated link providing for vertical movement of the mower unit relative to the frame and also for swinging movement about a horizontal front-to-rear swinging axis.

From another aspect the invention consists in a gang mower comprising a main frame connected to a number of individual mower units and including a means for driving the individual mower units including respective belt drives, each of the units being connected to the frame at one end with the belt drive at the same end, in which the connection between each mower unit and the frame provides for limited front-to-rear movement, and including a spring acting between the main frame and the mower unit urging the unit rearwards to tension the belt, and in which the connection between the mower unit and the main frame includes an articulated link comprising a pivot shaft lateral link.

According to a preferred feature of the invention the other end of the link is also connected to a similar articulated joint including a shaft connected to the link and extending from front-to-rear, and mounted in two spaced bearings for pivotal longitudinal movement.

Preferably the connection between each mower unit and the frame includes a transverse pivot providing for swivelling movement of the unit about a horizontal axis.

The invention may be performed in various ways and one specific embodiment with a number of possible modifications will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 is a diagrammatical plan view of a gang mower according to the invention, Figure 2 is a perspective rear view thereof, Figure 3 is a diagrammatic side elevation partly in section through the frame of the gang mower trailer, and Figure 4 is a detailed view partly in section illustrating one of the articulated links.

The gang mower illustrated in Figs. 1 to 3 is designed as a trailer for use with a tractor or other vehicle having a power take-off (P.T.O.). The trailer has two rear ground wheels 10, 11 and a front wheel 12 carried from a rigid frame 13 which has a towing connection 14, to a tow-bar on the vehicle or to a tractor's three point suspension. The trailer also has a connecting shaft 16 to be coupled to the P.T.O.

Mounted on the trailer are five separate mower units 20, 21, 22, 23 and 24, with two in the front row and three staggered in the second row to ensure full coverage. The mower units are all driven by belt drives 26, which are in turn driven by cross shafts and belts carried by the trailer frame 13 and driven by the P.T.O. 16.

The trailer frame 13 is resiliently connected to the ground wheels 11, 12 and is therefore essentially "sprung" and each of the mower units 20 to 24 is also resiliently and movably mounted on the frame. As illustrated each of the mower units is connected to the frame at one end only and the multiple articulated joint at this connection will be described in more detail below. The belt drive 26 to each unit is also positioned adjacent the same unit and it is found that this provides the best method to ensure proper tension on the belt while yet allowing adequate fredom of movement.

As illustrated in Fig. 4 each articulated joint comprises a link 30 which is connected at one end by tubes 31 to a bearing shaft 32 carried in a pair of spaced bearing bosses 33 rigidly secured to part of the trailer frame. The whole link 30 can thus move from front to rear and a spring 35 surrounding the shaft acts between a stop 35a and the link 30 to urge the link 30 in the direction of arrow X i.e. rearwards, thus asserting tension on the associated belt. The considerable spacing between the two bearing bushes 33, 34 restrains any twisting movement applied to the link. At the other end the link is similarly connected to a shaft 39 mounted on the frame of the mower unit.

The double articulated link 30 thus allows for vertical movement of each mower unit with some vertical swinging movement about the axis of the shaft 39.

In addition means may be provided for allowing each mower unit to swivel independently about a lateral horizontal axis. For this purpose, as shown in Fig. 4, the shaft 39 of each articulated link 30 is connected to a sleeve 45 having a swivel stem 46 mounted in a bearing or housing 48 carried by the mower unit body 47. Thus in addition to the articulated movement referred to above the body of the mower unit can swivel about a transverse horizontal axis. Each mower unit for this purpose has front and rear rollers 50, 51 which combine with the horizontal swivel to allow the unit to follow the contours of the ground independent of the trailer frame and of the other mower units. When this swivel facility is not required, the swivel joint can be locked and the swivelling movements are in any case limited by a pair of spaced bushes on the side plate of-the mower unit.

In an alternative arrangement the link 30 may be held longitudinally on the shaft 32, which in turn may be mounted for a for-andaft movement. In this case the spring 35 acts on the shaft 32 rather than the link 30.

Claims (8)

1. A gang mower comprising a main frame connected to a number of individual mower units, and including drive means for the individual mower units, each of the units being connected to the frame at one end by means of an articulated joint which includes a swivel bearing permitting movement of each mower unit about a generally horizontal transverse swivelling axis.

2. A gang mower according to claim 3 in which each mower unit has ground rollers or wheels positioned both in front of and behind the swivel axis, to allow the unit to follow the ground contour.

3. A gang mower according to claim 4, in which each articulated connection includes a double articulated link providing for vertical movement of the mower unit relative to the frame and also for swinging movement about a horizontal front-to-rear swinging axis.

4. A gang mower comprising a main frame connected to a number of individual mower units and including a means for driving the individual mower units including respective belt drives, each of the units being connected to the frame at one end with the belt drive at the same end, in which the connection between each mower unit and the frame provides for limited front-to-rear movement, and including as pring acting between the main frame and the mower unit urging the unit rearwards to tension the belt, and in which the connection between the mower unit and the main frame includes an articulated link comprising a pivot shaft lateral link.

5. A gang mower according to claim 4, wherein the spring acts between the main frame and the link.

6. A gang mower according to claim 4 or claim 5, in which the other end of the link is also connected to a similar articulated joint including a shaft connected to the link and extending from front-to-rear, and mounted in two spaced bearings for pivotal longitudinal movement.

7. A gang mower according to any one of the preceding claims, in which the connection between each mower unit and the frame includes a transverse pivot providing for swivelling movement of the unit about a horizontal transverse axis.

8. A gang mower substantially as hereinbefore described with reference to the accompanying drawings.