IE901669A1 - A pasture topper - Google Patents

Abstract

A pasture topper is disclosed which includes flails (10) rotating about vertical shafts (16). The flail shafts are driven by a primary drive shafts (11, 12) via an associated gearbox (17). Because gearboxes are used the flails do not slip and little maintenance is required. Further, there is no slip and the flails may have overlapping paths of rotation, as they remain rotationally offset with respect to each other. The pasture topper (1) is movable between a sidewardly directed cutting position and a rearwardly directed transport position. The topper is held in the cutting position by a spring biased latch which is arranged to slip if the topper (1) encounters an obstruction.

Description

A Pasture Topper AGRI PATENTS LIMITED an Limerick, Ireland.

Patent Application by Irish company of Barrington Street, - 1 The present invention relates to devices for trimming grass in pastures to assist growth, which devices are generally referred to as pasture toppers.

At present, pasture toppers generally comprise a drive shaft 5 which is driven by a tractor power take-off. Drive is transmitted to rotating flails via belts and pulleys. Many of the presently available pasture toppers are movable between a cutting position to the side of a tractor and a transport position directly behind a tractor. Locking arrangements are used to secure the toppers in each position.

One of the problems with such pasture toppers is that in wet conditions or if there is relatively thick growth, the belts slip on the pulleys, thereby reducing the effectiveness of the topper. Another problem is that the belts must be inspected and replaced at regular intervals and wear of the belts may damage bearings and other rotating parts of the topper. A further problem is that because slippage may occur it is not possible to have adjacent flails having overlapping paths of rotation because they may slip from offset positions to being in-line, which situation would be dangerous. A still further - 2 problem with presently available pasture toppers is that an obstruction such as a rock outcrop may damage the topper.

The present invention is directed towards providing a pasture topper to overcome these problems.

According to the invention, there is provided a pasture topper for trimming of grass, the pasture topper comprising a frame adapted for mounting on a tractor, the frame supporting a grass-cutting flail mounted on a drive shaft, the pasture topper further comprising a drive transmission comprising a primary drive shaft arranged for reception of power from a tractor power take-off, the primary drive shaft driving each flail drive shaft via an inter-meshing gear transmission.

In one embodiment, the primary drive shaft is substantially horizontally arranged the flail drive shaft is substantially vertically arranged and each gear transmission comprises mutually perpendicular bevel gears.

In one embodiment there are at least two flails and the intermeshing gear transmission of each flail is adapted to provide drive in the opposition direction to an adjacent flail.

In this latter embodiment, each flail has a path of rotation overlapping that of an adjacent flail, the flails being rotationally off-set with respect to each other.

•E 901669 - 3 Ideally, the frame includes a fixed frame for mounting on a tractor, and a pivoted frame pivotally connected thereto for movement between a sidewardly-directed cutting position and a rearwardly-directed transport position, the pasture topper further comprising a resilient clamp on the fixed frame or the pivoted frame for inter-engagement thereof at the cutting position of the topper, the clamp being arranged to slip for release of engagement if the pasture topper hits against an obstruction.

In one preferred embodiment, the resilient clamp comprises a spring biased latch member on the fixed frame or the pivoted frame for engagement with a stop on the other of the fixed frame or pivoted frame, the latch member and stop having inter-engaging forwardly and upwardly directed sloping surfaces.

Preferably, the pasture topper further comprises a hydraulic ram for movement of the pivoted frame between the cutting and transport positions, when one end of the ram is secured to the pivoted frame and the other is secured to a pivot arm mounted on the fixed frame, the clamp acting on the pivot arm.

The invention will be more clearly understood from the following description of some preferred embodiments thereof, - 4 given by way of example only with reference to the accompanying drawings in which:Fig. 1 is a perspective view of a pasture topper of the invention in use; Fig. 2 is a plan view of the topper in a transport position; Fig. 3 is a diagrammatic side view of the topper in the transport position; Figs. 4(a) and 4(b) are a plan view from underneath and a side view of portions of the topper; Fig. 5 is a perspective view showing the front portion of the topper; and Figs. 6(a) to 6(c) are various views illustrating the front portion of the topper in more detail.

Referring to the drawings and initially to Figs. 1 and 2 there is illustrated a pasture topper of the invention indicated generally by the reference numeral 1. The pasture topper 1 comprises a support frame 2 which includes a rectangular fixed frame 3 having lugs 4 for securing the topper 1 to a tractor three-point linkage. The support frame 2 also includes a - 5 pivoted frame 5 which is pivotally connected to the fixed frame 2 at pivot pins 6 only one of which is visible in Figs. 1 and 2. The pasture topper 1 is illustrated connected to a tractor 7 having a three-point linkage 8. The pivoted frame supports the various components of the pasture topper 1 and is movable by a ram actuating mechanism 9 between a rearwardly-directed transport position as shown in Fig. 2 and a sidewardly-directed cutting position as shown in Fig. 1.

The pasture topper 1 is illustrated in more detail in Figs. 3 10 to 6 , in which parts similar to those described with reference to the previous drawings are identified by the same reference numerals. Two rotary flails 10 are driven by primary drive shafts 11 and 12, an input of the primary drive shaft 11 being connected to a primary gearbox 13 having an input shaft 14 adapted for connection to a tractor power take-off (see Fig. 5). The primary drive shafts 11 and 12 are mounted on bearings 15. Each flail 10 is mounted on a vertically arranged flail drive shaft 16 which is driven by the primary draft shaft 12 via a secondary gearbox 17 comprising inter20 meshing mutually perpendicular bevel gears. The gearboxes 17 are arranged to transmit drive in opposite directions of rotation to each flail 10 and it can be seen in Figs. 4(a) and 4(b) that the flails 10 are offset by 90° and have over-lapping paths of rotation for effective grass cutting. A safety guard 18 with sides 19 is mounted on the pivoted frame 5. - 6 Referring specifically to Figs. 5 and 6, the front portion of the pasture of the pasture topper 1 including the ram actuating mechanism 9 is illustrated in more detail. The ram actuating mechanism 9 includes a two-way hydraulic ram 30 for connection by flexible tubes, not shown, to a tractor hydraulic system. The hydraulic ram 30 is mounted for transverse pivotal movement at a fixed bracket 31 on the pivoted frame 5 and at a movable bracket 32 on a pivot arm 33 which arm is pivotally mounted at a vertical pivot pin 34 on the fixed frame 3. A break-away arrangement 33 includes a clamping piece 35 of inverted V-shape on the pivot arm 33, the clamping piece 35 engaging a latch 36 having corresponding sloped engagement surfaces. The latch 36 is spring biased downwardly into engagement with the clamping piece 35 by a spring 37 mounted on a post 38. It will be seen that the latch 36 and the clamping piece 35 have inter-engaging forwardly and upwardly directed sloping surfaces 39.

In operation, the pasture topper 1 is moved by the ram actuating mechanism 9 to a cutting position as illustrated in Fig. 1. The primary gearbox input shaft 14 is connected to a power take-off so that drive is transmitted from the primary drive-shafts 11 and 12 to the flails 10 via the secondary gearboxes 17. The primary gearbox 13 includes step-up gears so that the flails 10 rotate at a relatively high speed. A positive drive action is achieved because drive is transmitted to the flails via the secondary gearboxes 17. The flails 10 - Ί do not slip in the most difficult conditions of relatively thick or wet grass. Grass cutting is particularly effective because the flails 10 rotate in opposite directions of rotation having overlapping paths. This has been achieved because there is slip in the drive transmission.

If the pasture topper hits an obstruction such as a rock outcrop while in the cutting position, relatively little damage will be caused because the latch 36 and the clamp piece 35 will disengage by movement upwards of the latch 36 against the action of the spring 37. This will allow the pivoted frame 5 to pivot freely when the topper hits an obstruction. The hydraulic ram 30 is thus used for normal movement between the transport and cutting positions, the latch 35 allowing movement only in emergency situations when an obstruction is encountered.

It will be appreciated that the invention provides a pasture topper which provides effective and positive grass trimming action, which positive action is achieved by the use of a gear transmission between the primary drive shafts and the flails.

This arrangement also facilitates the mounting of the flails for overlapping paths of rotation because the flails do not slip from their offset positions. Thus, effectiveness of the flails is significantly improved. It will also be appreciated that the break-away arrangement provided by the latch 36 and the clamp piece 35 considerably improves safety of the pasture - 8 topper and reduces the chance of damage being caused by an obstruction.

It will further be appreciated that the pasture topper of the invention is easier to maintain than presently available pasture toppers because there are no drive belts and pulleys. The gearboxes and bearings are enclosed in sealed housings so the only maintenance required is regular oiling.

It is envisaged that the pasture topper of the invention need not necessarily include a ram actuating mechanism and in this case a break-away arrangement similar to that of the pasture topper 1 may be mounted directly between the fixed frame and the pivoted frame.

The invention is not limited to the embodiments hereinbefore described but may be varied in construction and detail.

Claims (8)

1. A pasture topper for trimming of grass, the pasture topper comprising a frame adapted for mounting on a - 9 CLAIMS tractor, the frame supporting a grass-cutting flail 5 mounted on a drive shaft, the pasture topper further comprising a drive transmission comprising a primary drive shaft arranged for reception of power from a tractor power take-off, the primary drive shaft driving each flail drive shaft via an inter-meshing gear 10 transmission.

2. A pasture topper as claimed in Claim 1 wherein the primary drive shaft is substantially horizontally arranged the flail drive shaft is substantially vertically arranged and each gear transmission comprises 15 mutually perpendicular bevel gears.

3. A pasture topper as claimed in any preceding claim, wherein there are at least two flails and the intermeshing gear transmission of each flail is adapted to provide drive in the opposition direction to an adjacent 20 flail.

4. A pasture topper as claimed in claim 3, wherein each flail has a path of rotation overlapping that of an - 10 adjacent flail, the flails being rotationally off-set with respect to each other.

5. A pasture topper as claimed in any preceding claim wherein the frame includes a fixed frame for mounting on 5 a tractor, and a pivoted frame pivotally connected thereto for movement between a sidewardly-directed cutting position and a rearwardly-directed transport position, the pasture topper further comprising a resilient clamp on the fixed frame or the pivoted frame 10 for inter-engagement thereof at the cutting position, the resilient clamp being arranged to slip for release of engagement if the pasture topper hits against an obstruction.

6. A pasture topper as claimed in claim 5, wherein the 15 resilient clamp comprises a spring-biased latch member on the fixed frame or the pivoted frame for engagement with a stop on the other of the fixed frame or pivoted frame, the latch member and stop having inter-engaging forwardly and upwardly directed sloping surfaces. 20

7. A pasture topper as claimed in claims 5 or 6 further comprising a hydraulic ram for movement of the pivoted frame between the cutting and transport positions, wherein one end of the ram is secured to the pivoted frame and the other is secured to a pivot arm mounted on -lithe fixed frame, the resilient clamp acting on the pivot arm.

8. A pasture topper substantially as hereinbefore described with reference to and as illustrated in the accompanying 5 drawings.