As some of you may be aware, one of the long term objectives of various R. & D. workers who are involved with two wheel tractors, is the provision of a simple and effective mechanical lift system, for either the rear of the unit (for mounted implements and tool bars), or soil engaging tools (on both mounted tool bars as well as trailing implements).
Hydraulic lift systems, although very convenient, have largely been ruled out, as they are too complex and expensive, and cannot be quickly repaired in the event of a breakdown, in areas where only the local blacksmith is available to do the job. Electrically powered systems are also not favoured, as most two wheel tractors do not have any suitable electrical circuits which can be used.
Manual lift systems (operated by a lever or rotating wheel) are an alternative. They are fitted on some Brazilian made 2WT planters.
A Fitarelli two row trailed planter for 2WT is shown below. The raise/lower handle is circled. There is a similar raise/lower lever on the other side of the planter.
However they are awkward and can be very tiresome to use in small fields, where the planter tools must be raised and lowered every few minutes.
Older farm machinery (1930’s and 1940’s) in Western agriculture had mechanical lift systems which were driven by a ground wheel. They were popularly known as ‘rope trip lift’ systems. Pull the rope once to trip the mechanism, and the implement lifts. Pull it again, and the implement lowers to the operating position. The picture below shows an old US made ‘Van Brunt’ grain drill which is fitted with a rope trip lift’.
Can we utilize this principle to fabricate a similar mechanical lift for 2WT implements?
To do this, one needs a simple half revolution, or single revolution clutch, such as is fitted to a power press. The mechanism is normally in neutral mode, until activated by the operator. It then goes through one cycle (lifting or lowering) and then returns to neutral.
Below are four examples of single revolution clutches. The Youtube link to a short video is listed below the pictures.
Rotary key clutch
Ratchet 360 degrees
Pin clutch https://www.youtube.com/watch?v=wcYKttiovDA
Rotary key clutch https://www.youtube.com/watch?v=f6q34XHP5Aw
Ratchet clutch https://www.youtube.com/watch?v=4tz_Q8LhK90
Ratchet mechanism – 360 degrees. https://www.youtube.com/watch?v=nPXjauQj3AQ
Further details available on request.
Article By: Jeff Esdaile