11. A trunk engine locates the connecting rod " within " a large-diameter hollow piston rod . 12. More sophisticated cylinders have a body with end cover, a piston rod , and a cylinder head. 13. The company said the brake piston rod , which activated the service brakes, could bend or fracture. 14. Internal combustion engines, and in particular all current automobile engines, do not generally have piston rods . 15. A piston rod , connected vertically to the piston, extended out of the top of the cylinder. 16. Inlet steam was supplied to the top of the piston rod trunk through distinctive domed caps. 17. This is mitigated by a sliding block between the crank and the slot in the piston rod . 18. The bowstring pushed the piston rod back down as the gasses escaped and cooled, completing the cycle. 19. The high-pressure gases drive the piston rod ( which is attached to the bolt carrier ) rearward. 20. Oscillating engines had the piston rods connected directly to the crankshaft, dispensing with the need for connecting rods.
