Printable View for Presentation #14 (See also "Manual on a String").

Manual Rope Pump as prepared for publication by Demotech in 1979

This version of the Demotech rope pump was designed and build in Demotech's new workshop in Utrecht. After this prototype was build, there was doubt of the superstructure of the pump was a feasible design. The precondition of a concrete slap as a support seemed not realistic.
The way the pump axle is positioned related to the inlet-outlet block has to solved in a different way.

Author: Demotech, design for self-reliance
Version: Juli 27, 2008		 Feedback email info@demotech.org
Postal: Biesenwal 3, 6211 AD Maastricht, the Netherlands
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1

Rope Pump Super structure
Targets of this setup were:

  • The base could be masoned in a conventional way from the usual concrete blocks. Wooden bearing blocks for the axle fit in where a concrete block is left out. The heavy ferro-cement top should hold down these bearing blocks.
  • The inlet-outlet block fits with its ends in two more holes. To take out this part, it should shift all the way to one side, then turn diagonally and shift its other end free. Then it can be lifted out, together with the pump pipes and the bottom block.

    Author: Demotech, design for self-reliance
    Version: Juli 27, 2008    		 Feedback email info@demotech.org
    Postal: Biesenwal 3, 6211 AD Maastricht, the Netherlands
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    2

    The inlet-outlet block
    This part was of a sturdy disign, that has been used in practice, also in Peru. Note

  • The rope glides into the PolyEthylene or PVC-pipe guided by wood only. It does not use a trumped up end of the pipe as is now generally used. This construction works well if the two wooden parts fit precisely around the pipe or if the pipe is sealed at this place with bits of rope or cloth.
  • The sheet metal is nailed onto the wood around the inlet. The sheet can be bent up to catch up-sprouting water and bent down in a gutter to guide the water away.

    Author: Demotech, design for self-reliance
    Version: Juli 27, 2008    		 Feedback email info@demotech.org
    Postal: Biesenwal 3, 6211 AD Maastricht, the Netherlands
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    3

    The pump rope
    As will later be clarified with additional pictures, the disks are cut from rubber with a special tool. This tool makes disks that fit accurately in the pump pipe. Note:

  • The disk is kept in place with a small piece of rubber clamped between the windings or the rope. As the rope runs both directions, such little strips of rubber should be inserted on both sides of the disk.
  • This way of keeping the disk in place, though easy to do, did not satisfy. After a short time of use some of them fell out.
  • The rope is mounted with some pre-tension over the wheel. Stress on the rope because of pumping loosens up the rope, without undesirable looseness.

    Author: Demotech, design for self-reliance
    Version: Juli 27, 2008    		 Feedback email info@demotech.org
    Postal: Biesenwal 3, 6211 AD Maastricht, the Netherlands
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    4

    The bottom block
    The construction of fastening the pump pipes is copied from the inlet-outlet block. Note:

  • A U-shaped wooden block is clamped with re-rod ends between the two pipe fittings.
  • The three wooden parts together shape the channel that guides the pump rope from going down into going up. Proper wood working has to assure this channel is smooth from the first use.
  • As this bottom block is designed to function in a well, it has to be weighted down with a stone to prevent floating and bending of the plastic pipes.