Iske brothers and Israel L. Landis

In 1881, the Iske brothers got two patents granted for a design similar to the Minto wheel.

According to the patent, the working fluid is alcohol "or other volatile liquid".^[2] Air in the tubes is to be removed and the tubes are sealed (creating a partial vacuum).^[2]

The patent suggests lamps as heating sources.^[3][2]

The first patent describes glass for the bulbs and tubes.^[2] The second patent does not specify materials,^[4] but the construction implies metal. A later patent then clearly specify metal.^[5]

• US Patent US242454, granted to the Iske brothers
• 

• US Patent US243909, granted to the Iske brothers
• 
  Figure 1
• 
  Figure 3

Later the same year, Israel L. Landis got a patent for a similar engine. Different to the Minto wheel and the Iske brothers' patent, the engine was oscillating, not revolving.^[6] Landis suggested alcohol or ether as the volatile liquid.^[6] Landis suggested heating up the apparatus before removing the air from the bulb/chambers.^[6]

• US Patent US250821
• 
  Figure 1

In the following years, the Iske brothers were granted various patents, including some relating to modification and/or improvements on engines similarly to the Minto Wheel and an oscillating engine^[7] similarly to Israel L. Landis design.

• US Patent 253867 - Variation with Flexible Tubing and Endless Chain
• 
  Figure 1 - motor which rotates
• 
  Figure 4 - motor which oscillates

• US Patent 253868
• 
  Figure 1
• 
  Figure 2 and 3

• US Patent 271639
• 
  Figure 1
• 
  Figure 2 and 3

Drinking bird

The oscillating types by the Iske Brothers and Landis are related to the drinking bird toy.

The drinking bird is dating back to 1910s~1930s. The drinking bird was patented in the US in 1945^[8] and 1946^[9] by two different inventors.

• drinking bird US patents
• 
  Arthur M. Hillery, 1944
• 
  Miles V. Sullivan, 1945

Wally Minto's contribution

Wally Minto experimented with different working fluids. With the working fluids he used, he got the required temperature difference down, enabling the engine - for example - to run on solar power.^[10] Based on the working fluid, his improved wheel is also known as "Freon Power Wheel".^[11] Popular Science reported about in its March 1976 issue.^[11]

Examples

A working example of a Minto wheel was first published in a series of articles in The Mother Earth News, Issues #38 March, #39 May and #40 July 1976. Test units constructed by Mother Earth News (Issue 40, July 1976) and the MythBusters (Episode 24, December 5, 2004 – "Ming Dynasty Astronaut") did convert temperature difference into torque, but not as well as overenthusiastic boosters claimed.