Hiscox item 332 identifies a roller piston rotary engine as a loose rubber lining inside a cylinder that is rolled over by a three-armed roller spider. It is not the eccentric single rolling piston and sliding vane shown in the removed calculator.
Roller Piston Rotary Engine Topology
Inspect Hiscox item 332's three-armed roller spider and loose rubber lining through one illustrative cycle.
What the historical figure shows
A shaft carries a three-armed spider. One roller is mounted at each arm tip, and the three rollers bear against a loose rubber lining inside the fixed cylinder. As the spider rotates, the rollers progressively roll over the lining.
Hiscox labels the rollers A, the spider on shaft B and the rubber lining E. The brief source description does not identify admission and exhaust ports, pressure chambers, lining attachment, roller bearings, sealing details or valve timing.
What this visual demonstrates
The visual keeps the fixed cylinder, loose inner lining, central shaft, three equally spaced spider arms and three tip rollers recognizable through one illustrative rotation.
It does not calculate swept volume, flow, pressure, torque, power, efficiency, speed, stresses, contact force, friction, wear, sealing, temperature or performance.
Topology, not a dimensioned performance model
In the illustrative reconstruction, the three arm angles are separated by 120°. Each roller centre follows a circular orbit about the shaft while the roller remains visually adjacent to the loose lining.
No dimensions are supplied by the cited item, so the normalized proportions and lining deflection are for legibility only. They are not a derived roller-contact solution or historical scale drawing.
Illustrative cycle
Moving the cycle-position control rotates the three-armed spider and carries each roller around the inside of the lined cylinder. The lining is shown as a compliant inner ring to distinguish it from the fixed shell.
The animation does not assign a direction of steam flow or a power stroke because the source excerpt does not provide the port and pressure arrangement needed to do so.
Scope and correction boundary
The removed page substituted a different modern rolling-piston topology: an eccentric cylindrical roller, a sliding abutment, inlet and exhaust regions, and a displacement formula. Those elements are not Hiscox item 332; the adjacent item 333 separately describes an eccentric cylindrical piston with vibrating wings.
This candidate therefore restores the identifiable historical topology but remains partial. A full engine reconstruction would require a primary drawing or patent that establishes ports, chamber boundaries, lining constraint, sealing and timing.
Questions
Is the large inner element an eccentric rolling piston?
No. Hiscox identifies a loose rubber lining and three rollers on a spider.
Why is there no swept-volume calculator?
The source does not supply the chamber and port geometry required for a defensible displacement model, and the removed formula belonged to a different topology.
Does the lining shape in the animation reproduce an actual material solution?
No. It is a normalized visual cue for a loose compliant lining.
Can the visual predict power or sealing?
No. Pressure history, ports, timing, contact forces, friction, material properties and losses are unresolved.
Primary historical source
- Gardner D. Hiscox, Mechanical Movements, Powers, Devices and Appliances — item 332 identifies the loose rubber lining, three-armed roller spider, rollers A, spider B and lining E.
- Wikimedia Commons source record — edition and Internet Archive provenance for the scanned 1901 volume.
- Open Library bibliographic record — editions and catalog metadata for Hiscox's work.
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