Patents

PATENTS AND INNOVATIONS

The ‘Kulasinghe – CPC” System of Prestressing which has been used to practically all Prestressed concrete structures in Sri Lanka since 1956.
System of Board Piling and cylinder sinking making pioneer use of an Air-lift pump for core excavation and building up piles and cylinders by prcstressing hollow concrete cylinders together.
System of large-diameter concrete piling developed in 1951 for the construction of port structures. This included a novel method of floating out large diameter cylindrical piles and sinking them with the use of a combination of percussion arid water jet for core excavation and air-lift for removal of the soil.
A reduction gearbox, which is very compact and capable of a very high reduction ratio with good efficiency in transmission.
Developments in the use of rubber in the manufacture of various types of pumps ranging from large sand pumps for high resistance to abrasion, down to small pumps for domestic use where the use of rubber has resulted in economy and greater durability, especially against wear and corrosion.
Peristaltic Pump using a rubber diaphragm instead of the rubber tube normally used. This results in a simple mechanism and also eliminates dependence on the spring back of the rubber tube for suction. This pump can be used conveniently for tube wells and similar locations where complete submergence is necessary.
Peristaltic pump which avoids the pinching roller running over the tube.
A completely new type of positive displacement pump using only rotary action which can be used for high pressure duties as in Hydrostatic systems for pumping water or for use as a compressor. This pump can also be worked as a motor with high-pressure oil or medium pressure water or compressed air. This has very high potential in hydrostatic transmission both high pressure and medium pressure and in the compressed air field.
A 4 ft. span corrugated clay-roofing tile.
A fluidic-controlled pneumatic clay cutter for clay extruders.
A cheap machine for casting hollow floor slabs on the long line of prestressing. The end product is similar to the “Spiroll” slabs hut machine and is cheaper at first cost and in maintenance.
Flexible inflatable rubber core for forming ducts for prestressed concrete, capable of bending into tendon profiles but avoiding wobble common with conventional inflatable cores.
Insulation boards, hardboard, etc. using coir fiber waste.
Cement-bonded fiber sheets for cladding and roofing.
Structural members made of cement-bonded coir fiber.
Heavy hydraulic presses constructed in prestressed concrete.
‘Wirecon” is a high-strength concrete giving high flexural strengths for the construction of electric overhead traveling cranes etc.
“Wirecon’ concrete boat hulls (different from “Ferro cement” of Nervi).
Simple crane crab giving inching, medium, and high lifting speeds without change
Gearboxes for Variable Speed Motors.
Manufacture of prestressed clay roof purlins.
Development of “Hydrokinetic” drives for powering winches, cutter, etc. in Cutter Suction Dredgers. This replaces electric or hydrostatic drives.
“Tetra-cyl – The development of a concrete armour block for the protection of breakwaters and coast protection works, etc.
Panels for water tanks using thin GRP membrane in tension.
New type of manhole cover for sewer manholes and cable manholes.

PAPERS

Cement Gun Repairs to coaling jetties in Colombo (Engineering Association of Ceylon – 1949).
“The Application of Prestressed Concrete in Maritime Structures” – (Engineering Association of Ceylon – 1954)
“Prestressed Concrete in Sri Lanka, some typical examples”. (Journal of the Institution of Engineers, India – 1955)
“Precast Cylindrical Shell Roofs” (Presented at the International Symposium on Shell Structures, OSLO – 1957)
“The Development of Prestressed Concrete in Ceylon” (Presidential Address to Section C. Sri Lanka Association for the Advancement of Science – 1958)
“Umbrella shaped Hyperbolic Paradboloid Shells with Prestressed Edge Beams” (Presented at the International Symposium on Shell Structures, MADRID – 1959)
“An Indigenous system of post-tensioning for prestressed concrete Institution of Engineers, Ceylon 1959 (Co-author L J Weeraratne)
“Recent developments in Prestressed Concrete in Sri Lanka”, (Journal of the Institution of Engineers, India – March, 1960)
“Precasting of long saddle shaped Hyperbolic Paraboloid Shells on the long line”. (Discussion paper presented to the World Conference of Shell Structures, San Francisco – 1962).
“Design and Construction of the Planetarium Building in Colombo”. (Paper presented at the World Conference on Shell Structures, MEXICO 1967) Co-Author T. A. Ranaweera.
“National Report to the ESCAFE Conference on Industrialized Building”, (Copenhagen – September 1968 in the capacity of Consultant to the Conference)
Presidential Address to the Institution of Engineers, Sri Lanka – 1969. “Contributions to Engineering Development in Sri Lanka”
Presidential Address to the Sri Lanka Association for the Advancement of Science, 1970. “Some Contributions to Engineering Research and Development in Sri Lanka”.
“National Report to the Conference of Directors of Building Research in ESCAPE Regions”. (Melbourne and Sydney – March 1971)
“Prestressed Concrete in Industrial Buildings in Sri Lanka”. 1972. Silver Jubilee
Publication Research for Building Industry (1947 – 1972) by the Central Building Research Institute, Roorkie, India.
“Development and application of Ferro cement in Sri Lanka and Malaysia”. Paper presented to the Workshop on Introduction of Technologies in Asia – Ferro cement: A Case Study – November 5 – 8, 1974, Bangkok, Thailand.
“Rice husk fueled cement” – Paper presented at the 1981 Annual Sessions of the Institution of Engineers, (Sri Lanka). Co-author Dr. Susil Weeraratne.
“Inverted Conical Shell Roof for Long Clear Spans” Paper presented at the International Conference held in Bangalore. India in 1988.
“Design and Construction of Mahaweli Mahaseya”. Paper presented at the International Conference held in Bangalore, India in 1988.