Patent Design

By Staff
1 / 4
2 / 4
Restored 1910 Abenaque engine.
3 / 4
4 / 4

Gas Engine Patents of Note

If there’s one element that visually defines Abenaque
engines, it’s the unique cooling system designed by John
Ostenberg for Abenaque Machine Works owner Frederick Gilbert.
Ostenberg eventually went on to found the Ostenberg Manufacturing
Co. in San Jose, Calif., but he started his career in engine design
and manufacture with Abenaque in 1894. During his time at Abenaque,
Ostenberg applied for at least five different patents related to
improvements for gas-powered engines, all of which were assigned to

While Abenaque made traditional hopper-cooled engines, we can
safely assume Ostenberg’s design was motivated by an
appreciation of the limitations of hopper cooling, chief among them
the constant replenishing of cooling water while working in the
field. In his patent application of Jan. 21, 1901, Ostenberg stated
that the ‘main object of the invention is to obtain practical
means for water-jacketing a portable explosion engine of the kind
used, for example, in outdoor work, such as sawing wood and the
like, where the base of operation is frequently changed.’

Ostenberg’s invention neatly addressed this issue, employing
a pair of horizontally oriented cooling tanks (some engines were
equipped with a single, vertically oriented tank) to draw off
engine heat from the cooling water. The tanks had a thin
cross-section, ran more than the length of the engine and stood
approximately 1-1/2 feet tall. Thermo-siphon action cycled hot
water from the top of the cylinder into the cooling tanks at the
front. The heated cooling water then flowed the length of the
cooling tanks, during which time heat was drawn off. The cooled
water then ran back to the engine from the rear.

A head-on view of the Abenaque cooling system as designed by
John Ostenberg. The funnel for adding additional water was piped
into the connections at the rear, which otherwise mirrored those at
the front.

A ‘T’ connection at the front and rear of the tanks
allowed cooling water to flow evenly into and out of both cooling
tanks, and a funnel fitted at the rear ‘T’ allowed topping
off of the coolant, if required. The cooling tanks’ large
surface area meant the system only needed a few gallons of water to
effectively cool an engine, and an intended by-product of the
design was the control of pre-ignition from overheating.

Side and top views of Ostenberg’s cooling system as patented
Nov. 18, 1902. Hot cooling water entered at the front through a
‘T’ connection (shown in detail in Fig. 2). The cooled
water exited through a similar connection at the rear (b3 and b30
in Fig 1).

Ostenberg’s clever design was incorporated into the majority
of Abenaque engines, and there’s little question but that it
worked as intended. While not precisely a closed system,
Ostenberg’s design greatly limited the kind of evaporative
coolant loss that standard hopper-cooled and screen-cooled engines

Thanks in large measure to Ostenberg’s solid engineering
skills, Abenaque prospered for 22 years before finally shutting its
doors in 1916, a victim of increasing competition from larger

Further information on Abenaque Machine Works can be found in
the booklet Abenaque Machine Works by Patricia A. Haas and Alice C.
Caggiano, available through Farm Collector Books here at Gas Engine

Know of an interesting patent? Contact Gas Engine
Magazine at: 1503 S.W. 42nd St., Topeka, KS 66609, or e-mail us at:

Gas Engine Magazine
Gas Engine Magazine
Preserving the History of Internal Combustion Engines