AT RAC en

Forecart with pinned ring  & hitch ball

The ATRAC is a modular, lightweight horse-drawn hitch. Configurable single wheel forecart or single stretcher / trailer without wheel. It allows rapid interchangeability of trailers and tools.

This work is made available to all users of working horses to enjoy. After the field tests, the plans will be made available for free download. If you think this work has value, you can participate in its financing by contacting me directly: ujakame@gmail.com

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Versatile lightweight modular

The ATRAC is a concept between the interchangeable stretcher and the classic front train. It brings speed in the interchangeability of trailers and stretcher tools. The stretcher is coupled to a configurable coupler connection, simple and light, allowing its implementation by a single person.

Depending on the need, it can be configured as a simple stretcher / trailer junction or, with the addition of a jockey wheel (directional or free), as a multi-purpose front train.

The coupling process of the ATRAC is compatible with the standard ball joint coupling (car ball coupling, quad …) without noticeable modifications for the trailer.

Consequently, these qualities also make it possible to reduce the number of stretchers (save money and space) and to make tools and trailers usable by horses, cars, quads, etc.

The ATRAC, without its wheel, can be used to move a light trailer or a small tool. It is also possible to attach three-wheel side-discharge rakes.

Rigid coupling by hitch ball and pinned ring

The coupling between the front end and the trailer is done by a double attachment:

  • a standard ball joint / head assembly of automobile type

  • a ring secured to the towbar of the trailer through the false drawbar of the front train by a slot. A conical pin just clamps the ring so as to press the drawbar on the false drawbar.

The towbar is in charge of the traction forces.

The pinned ring blocks the pivotal freedom of the ball joint and thus rigidly secures the drawbar of the trailer on the ATRAC false drawbar .

The choice of the car-type coupling head stands out because of its low cost and compatibility with cars and tractors. It is quieter because it is adjusted and standardized (unlike the ring couplings) .

To keep the trailer compatible with car traction, the towing hitch on the trailer is not changed: Only one of the two nuts for attaching the trailer hitch is replaced by a ring nut .

To correct the balance between the drawbar and the false drawbar, or in the case of an irregularly shaped drawbar not guaranteeing a sufficiently level contact, it is possible to add a shim fixed on the second nut of the head of coupling.

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The elements of the front train:

The front train consists of 3 separate parts that can be mounted in several ways.

These three elements are all assembled with dowels or pins to allow a quick configuration of the front train in the field .

The stretcher

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The stretcher shown is a classic stretcher, but depending on the weight drawn by the tractor, it can be adapted to two or three-wheel hitch types, such as « ankle bolt «  (1 ) , mono-stretchers (2), or wood (like the Swiss munitions cart)

It is inadvisable to use the ATRAC with stretcher supporting the traction force (for example, in the prenans) but rather to use lines and a rudder. A regulator is fixed on the vertical part of the false drawbar. This assembly is also more versatile because the rudder is very easily removable. The horse, once unhitched, retains its line and its rudder, which allows it to be pulled very quickly a soil tool or skidding.

The false drawbar

Centerpiece of ATRAC, it is he who makes the link between the stretcher and the trailer.

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When the push bar (gray) is mounted, it is used to adjust the angle of the stretcher. If it is not mounted, the stretcher pivots freely on its axis.

The regulator (in gold) is clamped on the vertical part of the false drawbar so as to adjust the height of the point of traction.

It is preferable to place the regulator as low as possible because, during turns, the torsional forces on the coupling will be lower. Placing the regulator down also allows to unload the front train during the traction, which gives more horse traction and reduces the drag of the single wheel.

The jockey wheel

The jockey wheel is removable. Clamping is ensured by a head (yellow) pinned.

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This jockey wheel head can receive the stretcher. The stretcher is then oscillating about the axis and drives the direction of the wheel.

The jockey wheel can be:

  • Not mounted. The assembly of the stretcher is on the false drawbar.

  • Mounted and free (the jockey wheel is a crazy wheel). The stretcher is then either not mounted or mounted on the false drawbar.

  • Mounted and the stretcher mounted on the jockey wheel head: the jockey wheel is then director

The different arrangements according to the use

Stretcher not mounted / crazy jockey wheel

To pull a small trailer with a simple rudder or to move it by hand

Unmounted stretchers / hand-held jockey wheel (with bar)

To pull a small trailer with a simple rudder but guided by hand; for cultivation tools for example.

Note that the forward direction of the hitch can be reversed (the two fixed wheels of the trailer at the front and the steering wheel at the rear.The rudder is in this case attached directly to the tool.

Articulated stretcher on the false drawbar / crazy jockey wheel

Allows you to pull a trailer or a tool by relieving the weight on the horse’s shoulders, also allows to guarantee the hiding of certain tools. Keep the handy side of the two-wheel hitch.

Articulated stretcher on jockey wheel / jockey wheel headed by the stretcher

Makes the steering wheel jockey in the axis of traction of the horse. Pulls a heavier and more remote trailer without the horse working sideways (like a baler)

Stretcher mounted rigid on the false drawbar / no wheel jockey

Allows you to simply tow a small trailer

Videos / photos

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plans

ATRAC LITE plans

Licence

Creative Commons License
This work is made available under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike 3.0 France License .

The whole document, plan, photo, descriptions, etc … can be used, diffused and modified with the condition to quote the author: Denis ADAM – The small farm of Chanon.

Any total or partial recovery or reuse of this document must be subject to the same license as that of the original document: https://creativecommons.org/licenses/by-nc-sa/3.0/en/

Notes

(1) association hypothesis – Research on the Chevilatte Harness – http://hippotese.free.fr/blog/index.php/category/Research-on-the-Harnais-chevilatte

(2) association hippotese – The pass Everywhere – http://hippotese.free.fr/blog/index.php/tag/mono-brancard