Patent Description:
It is known to provide towed agricultural apparatus in which rotors carried by displaceble arms rake cut crop into swaths or windrows. Such towed agricultural apparatus are designed to be towed by agricultural vehicles. The arms of the agricultural apparatus are deployed substantially parallel to a ground surface as crop is raked ("the working position") and are raised substantially parallel to one another when the towed agricultural apparatus is not being used to rake crop, for example when the agricultural apparatus is being towed on public roads between fields ("the transport position"). It a known difficulty that it is desirable to have the rotors work as wide a width of crop as possible, leading to a desire for displaceable arms of longer lengths, while at the same time the height of a towed agricultural apparatus with the arms in the transport position is subject to legal limits. It is further known problem that movement of the arms between the working position and transport position is constrained by the presence of required elements, such as a drivetrain extending between a body of the towed agricultural apparatus and the rotors on the displaceable arms.

<CIT>) discloses a towed agricultural implement having the features of the precharacterising portion of claim <NUM>.

According to a first aspect of the present invention, a towed agricultural implement according to claim <NUM> is herewith provided. Preferred embodiments of the invention are provided in the dependent claims.

This has as an advantage that a sufficient overall length is available for the displaceable arm drive arrangement in the transport position.

This has as an advantage that the biased frame element and the bracket mounted to the frame of the intermediate drive element ensure that the angular deflection of the intermediate drive element remains constant as the support arm is raised and lowered.

Reference to terms such as longitudinal, transverse and vertical are made with respect to a longitudinal vehicle axis which is parallel to a normal forward direction of travel.

For the purposes of clarity some elements of the towed agricultural implement are shown in some Figures though not in others.

With reference to the Figures, a towed agricultural implement <NUM> suitable for raking cut crop into swaths or windrows is shown. As can most clearly be seen from <FIG>, the towed agricultural implement <NUM> comprises a support frame <NUM> a first end of which is adapted for connection to a towing vehicle by way of a hitch arrangement <NUM>. A second end of the support frame <NUM> is provided with ground engaging wheels <NUM> to support the towed agricultural implement <NUM> as it is being towed. In a middle region the support frame <NUM> is provided with a support portion <NUM>.

As can be seen the towed agricultural implement <NUM> is substantially symmetrical about the support frame <NUM> and accordingly only one side of the towed agricultural implement will be described in detail, the other side being understood to correspond.

The support portion <NUM> of the towed agricultural implement <NUM> is provided to each side with a displaceable arm <NUM> moveable between a working position and a transport position. Each arm <NUM> is in two parts comprising a main portion <NUM> and a depending portion <NUM>. The main portion <NUM> extends between a pivot mounting on the support portion <NUM> at a first end and a first end of the depending portion <NUM> at a second end. A second end of the depending portion <NUM> is connected to a central hub <NUM> of a rotary rake <NUM>. The main portion <NUM> is further connected to the support portion <NUM> by way of a first displacement apparatus <NUM> mounted between the support portion <NUM> of the support frame <NUM> and the main portion <NUM> of the arm <NUM> to control pivoting movement of the main portion <NUM> of the arm <NUM> about the pivot mounting on the support portion <NUM> (best seen in <FIG> of the second embodiment). The first displacement apparatus <NUM> may take any form, for example a hydraulic actuator. Using the first displacement apparatus <NUM>, the arm <NUM> may be controlled to adopt a working position in which the rotary rake moves the cut crop into swaths or windrows, a transport position or an intermediate headland position.

The central hub <NUM> of the rotary rake <NUM> carries a plurality of time arms <NUM> provided with sets of tines <NUM> depending from a distal end of each of the time arms. The tine arms <NUM> are arranged to travel along a cam path such that the sets of tines <NUM> are adapted to be raised and lowered as the tine arms <NUM> rotate around the central hub <NUM> during towing of the agricultural implement <NUM>. The central hub <NUM> is further provided with a ground engaging wheel arrangement <NUM> to support the rake rotor in the working position. It will be appreciated that the wheel arrangement <NUM> will no longer be ground engaging when the rotary rake <NUM> is in the headland position or in the transport position.

A suitable second displacement apparatus <NUM> (<FIG>) is located between the support portion <NUM> of the support frame <NUM> and an extension <NUM> extending upward from the first end of the depending portion <NUM>. This allows controlled displacement of the rotary rake <NUM> away from the support frame <NUM> as required.

A drive apparatus <NUM> is carried by the support frame <NUM>. The drive apparatus <NUM> is carried beneath the support frame <NUM>. A first end of the drive apparatus <NUM> is supported by the hitch arrangement <NUM> and is adapted to be connected to the towing vehicle, in particular to the Power Take Off (PTO) of the towing vehicle. A second end of the drive apparatus <NUM> is connected to a first end of an intermediate drive arrangement <NUM>. The drive apparatus <NUM> may take any convenient form, such as a Cardan shaft. The intermediate drive arrangement <NUM> may take any form, conveniently a gearbox.

A drive arrangement <NUM> is provided connected at a first end to the hub <NUM> of the rotary rake <NUM> and at a second end to a second end of the intermediate drive arrangement <NUM>. The drive arrangement <NUM> may take any convenient form, such as a Cardan shaft.

In the working position, power is transmitted from the PTO of the towing vehicle through the drive apparatus <NUM>, the intermediate drive arrangement <NUM> and the drive arrangement <NUM> to the rotary rake <NUM> in order to drive the time arms <NUM> about the hub <NUM> of the rotary rake <NUM>.

A first embodiment of a support for the intermediate drive arrangement <NUM> is shown in <FIG>. The intermediate drive arrangement <NUM> is supported from the support frame <NUM> by way of a frame member <NUM>. The frame member <NUM> comprises a parallel sided frame supported at a first end by a pivot bar <NUM>. The pivot bar <NUM> is supported by brackets <NUM> extending from an underside of the support frame <NUM>. The support frame <NUM> is further provided with mountings <NUM> extending from the sides of the support frame <NUM>.

An outer casing of the intermediate drive element <NUM> is connected to the second end of the parallel sided frame. The parallel sided frame is provided with a cross member <NUM> extending across a mid-portion of the parallel sided frame. First and second ends of the cross member <NUM> extend beyond the sides of the parallel sided frame.

Biassing elements <NUM> extend on each side of the support frame <NUM> from the mountings <NUM> to the respective ends of the cross member <NUM>. The biasing elements <NUM> conveniently take the form of springs.

In the working position of the rotary rake <NUM> (<FIG>), the relative positions of the gear elements hold the parallel sided frame in a raised position with the intermediate drive element <NUM> held close to the underside of the support frame <NUM>.

In moving to the headland position (<FIG>), the second end of the drive arrangement <NUM> may pivot with respect to the second end of the intermediate drive element <NUM>.

In moving to the transport position (<FIG>), the second end of the drive arrangement <NUM> acts to push the second end of the intermediate drive element <NUM> downward. The biased frame member is deflected, the parallel sided frame pivoting about the pivot bar <NUM> to lower the end of the parallel sided frame connected to the intermediate drive element <NUM>, such that the intermediate drive element <NUM> adopts a lowered transport position. In this way a sufficient overall length is provided for the drive arrangement <NUM> in the transport position.

In a second embodiment, shown in <FIG>, an alternative construction of the biased frame member is shown. In <FIG> only a second end of the drive apparatus connected to the intermediate drive element is shown.

As may be most clearly seen in <FIG> and <FIG>, the biased frame member comprises upper and lower pairs of spaced apart members <NUM>,<NUM>. The upper members <NUM> are connected at a first end to a first upper cross member <NUM>. Similarly, the lower members <NUM> are connected at a first end to a first lower cross member <NUM>. The upper and lower cross members <NUM>,<NUM> are vertically spaced from one another. The upper and lower cross members <NUM>,<NUM> are pivotally mounted in brackets <NUM> extending from an underside of the support frame <NUM>.

A substantially L-shaped bracket <NUM> is provided to which the intermediate drive element <NUM> is mounted. An upright portion of the L-shaped bracket <NUM> is provided with a rearwardly directed flange <NUM> on each side. A second upper cross member <NUM> connects the second ends of the upper members <NUM> to the flanges <NUM>. Similarly, a second lower cross member <NUM> connects the second ends of the lower members <NUM> to the flanges <NUM>. The upper and lower cross members <NUM>,<NUM> are pivotally mounted the flanges <NUM>.

The biased frame member, as in the previous embodiment, is provided with a cross member <NUM> extending across a mid-portion of the biased frame member. In the illustrated embodiment the cross member <NUM> is fixedly connected to the upper members <NUM> in any suitable manner. The cross member <NUM> extends across the upper members <NUM> of the biased frame member, between the biasing elements <NUM> depending from mountings <NUM> on the support frame <NUM>.

It can be seen that the upper and lower members <NUM>,<NUM> together with the brackets <NUM> and the flanges <NUM> of the bracket <NUM> form a parallelogram arrangement such that in movement of the support arm between the working position and the transport position (and back again) the angular deflection of the intermediate drive element <NUM> (and in particular a front shaft of the intermediate drive element) remains constant.

Additionally, most clearly in <FIG>, the support frame <NUM> is provided with a further bracket <NUM> to which a resilient buffer <NUM> is secured. This acts as an end stop end stop for the intermediate drive element <NUM> as the displaceable arm <NUM> is lowered to the working position and the intermediate drive element <NUM> is raised towards the underside of the support frame <NUM>.

Claim 1:
A towed agricultural implement comprising
a support frame (<NUM>) one end of which is adapted for connection to a towing vehicle; support arms (<NUM>) carried from the support frame (<NUM>), each of the support arms (<NUM>) being moveable between a working position and a transport position;
each support arm (<NUM>) being provided with at least one rotary rake (<NUM>) carrying a plurality of time arms (<NUM>) adapted to be driven about a central rake axis;
a drive apparatus (<NUM>) carried by the support frame (<NUM>), one end of the drive apparatus (<NUM>) being adapted for connection to the towing vehicle;
a drive arrangement (<NUM>) adapted to connect the at least one rotary rake (<NUM>) to the drive apparatus (<NUM>) carried on the support frame and to drive the time arms (<NUM>) of the at least one rotary rake (<NUM>);
characterised in that
an intermediate drive element (<NUM>) connecting the support frame drive apparatus (<NUM>) and the drive arrangement (<NUM>) is moveably supported from the support frame (<NUM>).