IES67364B2

IES67364B2 - Improved suspension unit for an agricultural mower or topper

Info

Publication number: IES67364B2
Authority: IE
Inventors: Patrick Hughes
Original assignee: H & K Dev Limited
Priority date: 1995-10-13
Filing date: 1995-10-13
Publication date: 1996-03-20
Also published as: IES950796A2

Abstract

A suspension unit for use with an agricultural mower having a hitching member (3) and a drive line housing (5) which are pivotally linked is provided. The suspension unit comprises a spring loaded hydraulic ram (1) disposed between the member (3) and the housing (5). The ram (1) is operable by hydraulic fluid to bring the member (3) and housing (5) into closer juxtaposition for transporting the mower 60. An agricultural mower has a mowing head connectable to a prime mover by a two-part coupling arm comprising a hitching member (3) and a drive line housing (5) which are connected through a pivot (7) and are relatively moveable with respect to one another by a suspension unit disposed therebetween. In a mower cutting mode, the suspension unit provides active suspension under the action of a compression spring (14). In a mower transportation mode, limited suspension is provided to prevent the mower head moving excessively during transportation.

Description

IMPROVED SUSPENSION UNIT FOR AN AGRICULTURAL MOWER OR TOPPER The present invention relates to a suspension unit for use with an agricultural mower or topper.

Mowers and toppers trailed by a prime mover generally operate in one of two modes, a cutting mode where the mower or topper is disposed to the rear or to one side of the prime mover and the mowing heads are close to the ground and a transportation mode where the mower or topper is positioned behind the prime mover and the mowing heads are elevated for additional clearance. The operating principles of a mower and a topper are substantially similar and accordingly hereinafter any reference to a mower should be taken to include a topper. In known mowers a pair of wheels is provided towards the rear of the mower for supporting the weight of the mowing head. These wheels are connected to the mower through a hydraulic ram which raises the rear of the mower in the transportation mode to prevent the cutting head blades hitting the surface over which the mower is being drawn. Additionally, a spring suspension system is provided in the axle assembly of the wheels. However, the leading edge or front of the cutting head is not raised significantly and may become damaged due to its close proximity to the surface. If the surface over which the mower is being transported undulates significantly, the suspension may react so that a bouncing action occurs increasing the probability that the mowing head will strike the surface. Additionally, as these suspensions are arranged to activate when the mower is moved from the cutting mode to the transportation mode, a complex arrangement of suspension linkages is often required. - 2 It is an object of the present invention to provide an improved mower suspension unit. t Accordingly, the present invention provides a suspension 4 unit for use with an agricultural mower having a hitching member and a drive line housing which are pivotally linked, the suspension unit comprising a spring loaded hydraulic ram pivotally disposed between the member and the housing, the ram being operable by hydraulic fluid to bring the member and housing into closer juxtaposition for transportation purposes, whereby in the operational mode of the mower the member and housing are relatively moveable under the action of the spring.

Advantageously, the spring loading of the hydraulic ram is provided by a compression spring.

The present invention further provides an agricultural mower moveable between a cutting mode and a transportation, mode, the mower having a mower head connectable to a prime mover by a two-part coupling arm, the arm comprising a hitching member and a drive line housing disposed between the mower head and the hitching member, in which the hitching member and the drive line housing are connected through a substantially horizontally disposed pivot and are relatively moveable with respect to one another by a suspension unit disposed therebetween, the suspension unit having a first configuration when the mower is in the cutting mode where active suspension is provided by the unit and a second configuration for use in the transportation mode where limited suspension is provided to prevent the mower moving excessively during transportation.

The suspension unit includes an inlet for pressurised fluid for moving the unit between its first and second configuration.

The invention will now be described more particularly with reference to the accompanying drawing which shows, by way of example only, one embodiment of suspension unit according to the invention. In the drawing, a suspension unit comprising a spring loaded hydraulic ram 1 is fixed between a hitch member 3 having a hitch H for securing a mower to a prime mover and a drive line housing 5 through which power is communicated from the prime mover to the mowing head of the mower. The housing 5 and hitch member 3 are joined through a pivot pin 7 which allows relative vertical movement limited by the action of the ram 1 . The ram 1 comprises a cylindrical housing 10 which is closed at one end and a piston 12 on which a compression spring 14 is mounted. The cylindrical housing 10 is pivotally mounted on the drive line housing 5 by a spur 15 which sits into a receiver 16 mounted on the wall of the cylindrical housing 10. The piston 12 is similarly mounted on the hitch member 3 by a spur 17 pivotally retained in a spur receiver 19 at one end of the piston 12. The compression spring 14 is fixed to the piston 12 at the other end and abuts a threaded cap 20 which retains the spring within the cylindrical housing 10. When the mower is in its cutting mode, the piston 12 is in an extended position and the compression spring 14 is in its normal operating position. A hydraulic inlet 23 is provided in the side wall of the cylindrical housing 10 so that when pressurised fluid is pumped into the housing, the ram 12 is forced to retract into the housing and the compression spring 14 is extended. Minimal suspension action is available in this configuration, so that the mower does not tend to bounce when being transported along roads.

In use, the cylindrical housing 10 of the ram 1 is ; pivotally attached to the drive line housing 5 and the piston 12 is pivotally attached to the hitch member 3 by <“ their respective spurs 15,17. The hitch H is secured to the hitching post of a prime mover such as a tractor (not shown) and the mower is moved into its cutting mode. In this position, the ram 1 is not provided with a pressurised hydraulic feed at the inlet 23 and the piston is extended by the force of the spring 14. The mower body (not shown) will lie substantially parallel to the ground until rough terrain is encountered at which time the ram 1 will provide smooth operation by its action.

When the mower is moved to the transportation mode, a pressurised hydraulic feed, usually supplied from the prime mover, is applied to the inlet 23 to retract the piston 12, forcing the end of the hitch member 3 to be drawn closer to the drive line housing 5. This action causes the drive line housing 5 to be deflected upwardly thus lifting the front of the mower.

It will of course be understood that the invention is not limited to the specific details described herein, which are given by way of example only, and that various modifications and alterations are possible within the scope of the appended claims.

Claims

CLAIMS :

1 . A suspension unit for use with an agricultural mower having a hitching member and a drive line housing which are pivotally linked, the suspension unit comprising a spring loaded hydraulic ram pivotally disposed between the member and the housing, the ram being operable by hydraulic fluid to bring the member and housing into closer juxtaposition for transportation purposes, whereby in the operational mode of the mower the member and housing are relatively moveable under the action of the spring.

2. A suspension unit as claimed in claim 1, in which the spring loading of the hydraulic ram is provided by a compression spring.

3. An agricultural mower moveable between a cutting mode and a transportation mode, the mower having a mower head connectable to a prime mover by a two-part coupling arm, the arm comprising a hitching member and a drive line housing disposed between the mower head and the hitching member, in which the hitching member and the drive line housing are connected through a substantially horizontally disposed pivot and are relatively moveable with respect to one another by a suspension unit disposed therebetween, the suspension unit having a first configuration when the mower is in the cutting mode where active suspension is provided by the unit and a second configuration for use in the transportation mode where limited suspension is provided to prevent the mower moving excessively during transportation.

4. An agricultural mower as claimed in claim 3, in which the suspension unit includes an inlet for pressurised fluid for moving the unit between its first and second configuration.

5. A suspension unit for use with an agricultural mower 5 substantially as herein described with reference to and as shown in the accompanying drawing.