[Stoves] Bisschop - part 4

[Jeff Davis]

Dear List.


rom “Internal Fire”
by Lyle Cummins

Intake and exhaust were controlled from a single, spool-type valve actuated by 
bell crank linkage off an eccentric on the crankshaft. When the valve was 
“down” air and gas were drawn into the cylinder through metering ports and 
past flat, rubber check valves. Combustion pressure closed the flap valves, 
yet no fire reached back to the rubber valves because they were upstream of 
where a burnable mixture was formed. The spool valve moved slowly upward 
after ignition and opened the cylinder to the exhaust pipe at the end of the 
power stroke. Flywheel inertia carried the piston downward, and the exhaust 
gases were pushed out through the common cylinder intake and exhaust port. No 
governor was required to control engine speed.

Ignition was commenced by a gas flame directed through a port about one-third 
of the way up the cylinder. As the piston uncovered this igniter port, the 
below atmospheric pressure in the cylinder (intake was still occurring) 
opened an inwardly acting metal flap valve to allow a jet of flame to enter 
and ignite the charge. The resultant quick pressure rise closed the igniter 
flap valve to retain cylinder pressure. Since the combustion explosion 
usually snuffed out the ignition flame, a second, continuously burning flame 
was located below the igniter jet to relight it for the next cycle. A cold 
engine required about eight to ten minutes of flame heating at the base of 
the cylinder before it could be started. Most engines had a gas jet located 
under the cylinder head for this purpose.

The Bisschop engine's success is evidenced by its continuous production for 
over twenty-five years by J.E.H. Andrew, Ltd in stockport, England. Andrew 
was reported to have built 2,000 of them by 1884. Buss, Sombart and Co. of 
Magdeburg, Germany, produced the engine from 1878 to 1886. Their one-third 
horsepower model had a bore and stroke of 100 mm by 290 mm and ran at 110 
rpm; overall height was 115 cm. Mignon and Rouart of Paris was the principal 
French manufacturer. All of the engines were built under patent licenses from 
Bisschop. The license was particularly important to Buss, Sombart because 
they needed an engine to build that would not infringe the Otto four-stroke 
cycle engine patent while it was in force. Almost every major technical 
museum contains one of these simple and practical little engines



That's it, for now!

Jeff
-- 
Jeff Davis
Somewhere 20 miles south of Lake Erie, USA
http://www.velocity.net/~jeff0124