Edmund Cartwright
Edward (Edmund) Cartwright (April 24, 1743 in Marham, Nottinghamshire – October 30, 1823 in Hastings, Sussex) was an English clergyman and inventor of the power loom. He was a clergyman of the Church of England and lived at Marnham in Nottinghamshire, England. He was educated at University College, Oxford.
More fortunate than his predecessors, he attacked the problem of mechanical weaving after much initial work had been done, especially that relating to mechanical spinning and the factory system, for without these no power loom could succeed.
1784 He designed the first power loom in 1784 patented it in 1785, but it proved to be valueless.
In the following year, however, he patented another loom which has served as the model for later inventors to work upon. He was conscious that for a mechanically driven loom to become a commercial success, either one person would have to attend several machines, or each machine must have a greater productive capacity than one manually controlled.
The thought and ingenuity bestowed by Dr Cartwright upon the realization of his ideal were remarkable. He added parts which no loom, whether worked manually or mechanically, had previously been provided with, namely, a positive let-off motion, warp and weft stop motions, and sizing the warp while the loom was in action. With this machine he commenced, at Doncaster, to manufacture fabrics, and by so doing discovered many of its shortcomings, and these he attempted to remedy: by introducing a crank and eccentrical wheels to actuate the batten differentially; by improving the picking mechanism; by a device for stopping the loom when a shuttle failed to enter a shuttle box; by preventing a shuttle from rebounding when in a box; and by stretching the cloth with temples that acted automatically.
In 1792 Dr Cartwright obtained his last patent for weaving machinery; this provided the loom with multiple shuttle boxes for weaving checks and cross stripes. But all his efforts were unavailing; it became apparent that no mechanism, however perfect, could succeed so long as warps continued to be sized while a loom was stationary. His plans for sizing them while a loom was in operation, and also before being placed in a loom, both failed. Still, provided continuity of action could he attained, the position of the power loom was assured, and means for the attainment of this end were supplied in 1803, by William Radcliffe, and his assistant Thomas Johnson, by their inventions of the Beam Warper, and the Dressing Sizing machine.
c.1807 Featured in the painting of 'Men of Science Living in 1807-8', reproduced as an engraving by George Zobel, and William Walker[1]
In 1809 Cartwright obtained a grant of £10,000 from parliament for his invention. He also created a wool combing machine and an alcohol-driven engine.
Edmund Cartwright's investigations were by no means limited to textile machinery. He took out twelve patents between 1785 and 1801. An account of his life and his work, containing many of his own writings, was published in 1843, and another edition was published in 1971 [2].
Steam Engines
Rev. Cartwright invented a steam engine having two connecting rods driving two gearwheels which meshed with each other. Presumably the aim was to avoid the complication of parallel motion linkage or guided crossheads. He also invented a type of piston packing using spring-loaded metallic rings. In theory this was a great advance on the long-established soft packing, but it seems that the arrangement was incompatible with the standard of cylinder bore machining obtainable at that time [3]
Cartwright's 1797 engine patent had a number of interesting features in addition to those mentioned above. Cartwright envisaged operating either with steam or with a volatile spirit which would be condensed and returned to the vaporizer (or decanted if the engine was used in the distilling process!).
When the piston neared the top of its stroke, it pushed open a valve in the cylinder cover to admit steam. The valve remained open until pressed down by an external arm connected to the descending piston rod.
On nearing the bottom of the cylinder, a valve located within the piston was pushed open by its spindle contacting the cylinder floor. This allowed steam rom above the piston to pass down into the condenser.
The condenser comprised two closely-spaced concentric thin cylinders, the steam passing into the small space between them, with water on the outside and inside of the vessel. The narrow gap ensured that all of the steam was compelled to be close to a cold metal surface.
The engine's piston rod was extended downwards into a smaller diameter cylinder, and a piston was attached to the bottom of the rod. This drew the air and condensed steam out of the condenser, and lifted it into a small closed tank, whence it was delivered back to the boiler. Air gradually accumulated at the top of this tank, and in so doing it pushed the water level down, until it reached a level at which a float valve was activated to release the air to the atmosphere.
Having reached the bottom of the stroke, the energy in the flywheel raised the piston to repeat the cycle (there now being a vacuum above and below the piston).
The engine was well described in Rees's Cyclopedia and in John Farey's 'Treatise on the Steam Engine'. Farey observed that Cartwright built some small engines, but they were not successful, largely because the surface condenser did not act sufficiently rapidly (i.e. there was inadequate surface area, and the external cooling water was static).
Cartwright later made a two cylinder version, which was installed at a mill in Wisbech. It did not perform the work required, and was moved to the Duke of Bedford's farm at Woburn, but it was unsatisfactory, and was scrapped. However, Cartwright's piston was developed and was found superior to hemp-packed pistons for high pressure steam.
See Also
Sources of Information
- [3] Wikipedia