Force and Work Measurements: The Beginnings

Force and Work Measurements: the Beginnings Regnier’s Dynamometer (1798) SPS, Fribourg, June 6, 2014! Abstract Force and work measurements: the beginnings The first practical, portable “dynamometer”, designed in 1798 by Regnier, was used to quantify the muscular strength of men and animals. It was promptly used by ethnologists to test the strength of the “savages”. A smaller improved model (Collin dynamometer) is still sold to medical and para-medical practitioners. With the development of agricultural and industrial machinery from the beginning of the 19th c., the need arose to measure not only the force between a motor and a load, but also the work done and the delivered power. Inventors and mechanics competed to combine heavy force-measuring machinery with newly invented delicate, precise graphic-recording apparatus and/or integrators and planimeters. 2 W. A. Benton (1941) Before Regnier (I): Spring balances based on Hooke’s law Deformation (strain) ∝ Stress (force or torque) (as long as the elastic limit is not exceeded) • Helical, spiral, V or C-shaped, …open spring balances known and used during all the XVIIIth c. • Quick measurements, convenient to use, but imprecise, limited dynamic range. • In most countries, use for commercial transaction or taxation purpose (involving money) not allowed. Used to measure amounts of matter (i.e. mass) through g, not forces. 3 Before Regnier (II): The best known of a few forerunners: J. Pearn: Two early dynamometers (1978) Engravings from Desaguliers (1763) – Graham-Desaguliers (1763) Measures the forearm strength by lifting a weight. Limited use. Not portable. Early XIXth c. : most work still done by men and animals! – Charles Augustin de Coulomb (1736-1806): Publishes in 1799 the results of his experiments on the “work” you can get from a man, in many different activities. No separation between the physiology and the mechanics. Carrying a load on a flat road is considered as work. Cf. Hachette: Traité des machines (2e éd., 1819), Christian: Traité de mécanique (1822), Poncelet: Mécanique industrielle (1870), etc. A simple, portable instrument to measure the strength of men and animals was needed ! 4 Regnier & his Dynamometer (1798) Edme Regnier (1751-1825) works at Paris from 1789, where he supervises the fabrication of weapons. About 75 inventions, among them the secateur (?) and the DYNAMOMETER Displayed at UNIL Physics Museum (Inv. 603.162); tested by M. D. Colladon jr. in 1841 5 Regnier’s “DYNAMOMÈTRE” (1798) First portable, versatile, easy to use dynamometer (first apparition of the word) Oval/elliptical one-piece closed spring Two scales: – compression forces – tension forces A pointer registers the maximum of the force Dynamometer by Arnheiter, the mechanic who had worked for Regnier. Private collection of J.-F. Loude From Hachette : Traité élémentaire des machines (2e éd., 1819) Measures: • strength of men (“force ordre des mains”, “force ordre des reins”) • traction force of animals • resistance to traction of carts (ammunition wagons, gun carriages,…) But doesn’t measure mechanical work ! 6 Dynamometers evolved in two directions: I. Anthropology, medicine and sport The Regnier Dynamometer was immediately adopted by anthropologists wanting to compare the strength of the European men and of the “Savages” they met during their exploration voyages around the globe. The results didn’t always agree with their expectations! (Péron in 1807, Quetelet in 1846, the Austrian HMS Novara expedition (1857-59), etc.) Similar oval-spring dynamometers were developed during the XIXth c., for testing human muscle strength (Tiemann in the USA, etc.) Also used in strongmen championships (late XIXth c. – early XXth c.) From about 1860, Mathieu sold a smaller version for the Regnier’s dynamometer, also made by Collin. Recommended by Hammond and Broca, it was widely adopted for medical and para-medical use. The “Collin dynamometer” is still available Mathieu/Collin dynamometers Private collection of J.-F. Loude today (≈ EUR 125). 7 E. Claparède (1873-1940) in 1921 www.notrehistoire.ch II. Mechanical work measurement Eugène Burnand : Le Labour dans le Jorat (1916) — Musée Eugène Burnand, Moudon (Switzerland) TD TD : Transmission Dynamometer, inserted between motor (animal, steam engine, etc.) and pulled load (plough, cart, railway carriage, boat, etc.). 8 Transmission Dynamometers: • Measure mechanical work, should be called Ergometers • Different models: • for linear motion • or for rotary motion, either: • Man turning a crank • Pulley and Belt transmission • Drive-Shaft transmission Wikimedia – Commons (Ad Meskens) Wikimedia – Commons (Lokilech) • Linear motion : work W is the product of force F by space x • Rotary motion : work W is the product of torque τ by rotation angle ϑ power P is the product of torque τ by rotation rate ω • Combine heavy machinery (strong spring to measure force or torque) and a precision, delicate apparatus (integrator or curve tracer), normally made for office or laboratory work. Field work difficult! 9 Short digression about the history of Planimeters & Integrators Adapted from Drechsler & Haeberlin (2011) Early XIXth c. : need to measure the areas on cadastral plans (taxation!) y (x) N Count the number N of turns made by the sliding wheel : y (x) N N ∝∫y(x) dx x Dynamometer : Cone and wheel integrator x ∝ x or ϑ y ∝ F or τ x Disk and wheel integrator 1837 : Disk and wheel integrator used by Morin in his traction and rotary “totalizing” dynamometers Uni Delft through Savoysky (2002) Cone and wheel planimeters were invented independently several times: 1814 : First one by Johann Martin Hermann (Bavaria) No publication, scrapped, forgotten until 1855 1816 : Tito Gonella (Tuscany) 1826 : Johannes Oppikofer (Switzerland) 1851 (!) : John Sang (Scotland) 10 Ca. 1850 : First disk and wheel planimeter by C. Wetli in Switzerland Planimeters & Integrators : Oppikofer–Ernst The Swiss J. Oppikofer designs in 1826 the first successful cone-and-wheel planimeter, later made by Ernst at Paris, much used by surveyors. Drechsler & Haeberlin (2011) from Bauernfeind (1853) A. Morin, in 1841, describes the Ernst planimeter in his “Notice sur divers appareils dynamométriques” Jervis-Smith (1915) from Morin (1841) Jervis-Smith (1915) from Morin (1841) 11 Catalogue Deleuil (1865) Planimeters & Integrators (after 1851) 1851 : The Great Exhibition at Crystal Palace (London) First opportunity to compare the instruments and machines off all countries Drechsler & Haeberlin (2011) The sliding motion of the wheel limits the precision. How to suppress it ? UNIL Physics Museum – Inv. 603.816 1854 : Jakob Amsler’s Polar planimeter : simple, “cheap”, for every surveyor and engineer. 1875 : James Thomson (brother of William) invents the Disk, Ball and Cylinder integrator. Hugely successful! An improved version is still manufactured. It opens the way to scientific analog computers. 12 Back to dynamometers: Horse & Plough (linear motion) Arthur MORIN (1795-1880) : student, and later collaborator, of Jean-Victor PONCELET (1788-1867) Catalogue Deleuil (1865) CNAM (1905) – Mécanique He adopts the “Poncelet Dynamometer”, with 2 plano-parabolic steel strips Rühlmann (1862) Made by Clair at Paris F vs. x : pen recording on a paper roll ⇒ W : integration by Ernst planimeter Jervis-Smith (1915) from Morin (1841) 13 Dynamometric Crank (rotary motion) Rühlmann (1862) What is the mechanical work done by a man turning a crank ? According to Christian (1822-25), one of the 9 ways to get rotary work from a man E. Regnier is credited with the invention of the “Manivelle dynamométrique”, later improved by Morin and manufactured by the mechanic Clair, at Paris. Catalogue Deleuil (1865) 14 Belt and Pulley drive (rotary motion) — I. MORIN (ca. 1840) Jervis-Smith (1915) from Morin (1841) Pulley A receives the belt coming from the motor, pulley B drives the machinery under test through a second belt. A spring is inserted between pulley B and the shaft. C is an loose pulley, for start and stop. Paper strip recorder (τ vs. ϑ) CNAM (1905) – Mécanique Motor belt Load belt The paper strip pen recorder can be replaced by a disk-and-wheel integrator, that directly totalizes the work done during the test. In both case the recording device / totalizer is rotating with the pulleys! 15 Drechsler & Haeberlin (2011) from Morin (1837) Belt and Pulley drive — II. Further developments Bourdon dynamometer (1860): Helical gears generate an axial force F proportional to the transmitted torque. Dial not moving! Bourdon (1860) F Richard (1882) Motor belt Von Hefner-Alteneck (Siemens) dynamometer (ca. 1880) measures the difference between the tensions on the leading side and on the trailing one of the belt. Only one belt ! 16 Richard (1882) Shaft drive (rotary motion) How to transmit the torque exerted on a rapidly rotating shaft to a stationary measuring/recording device ? en.wikimedia – Differential Cut the shaft and insert a spring between the two parts, or use the shaft itself as a torsion spring, ϑC ϑL and use some form of differential ! ϑR ϑC = ½ (ϑL + ϑR) (if ωL = -ωR , then ωC = 0 : the casing doesn’t rotate) Shaft (torsion spring) Example : “Pandynamomètre” Differential de G. A. Hirn (1867) Totalizer 17 Richard (1882) CONCLUSIONS From ca. 1820 to 1840, Arthur Morin, designed the first traction dynamometers (what is the best plough?) and the first rotary ones, for belt drive. From ca. 1830 to the end of the XIXth c., tens of models of transmission dynamometers have been invented, mainly to measure the work and power delivered to machinery. Only a few examples have been shown. Many more are described by Rühlmann (1862 and 1875), Guerout (1881), Richard (1882 to 1891), Jervis-Smith (1915), … More than 50 dynamometers of all times and types are stored at the “Musée du CNAM”, near Paris. No images are available… What I didn’t speak about : Absorption Dynamometers, that measure the power of a motor: put a brake and measure the torque or convert the power into something measurable (heat). 18 ¡ Thank you for your attention ! 19 Selected bibliography (in chronological order) Regnier, E. : Description et usage du dynamomètre. Journal de l’Ecole polytechnique T. II (1798) p. 160 Hachette, J. N. P. : Traité élémentaire des machines (2ème éd., 1819) Christian, G. J. : Traité de mécanique industrielle (3 vols, 1822-1825) Morin, A. : Mémoire sur deux appareils dynamométriques… Bulletin de la Société d’Encouragement pour l’Industrie Nationale 36ème année (mai 1837) 161 Morin, A. : Notice sur divers appareils dynamométriques (2ème éd., 1840) Ernst : Description d’un instrument nommé planimètre, ... Bull. de la Société d’Encouragement pour l’Industrie Nationale No 448 (1841) 402 Bauernfeind, C. W. von : Die Planimeter von Ernst, Wetli und Hansen, ... (1853) Bauernfeind, C. W. von : Geschichte der Planimeter. Polytechnisches Journal, Bd. 137, Heft XXII (1855) 81 Rühlmann, M. : Allgemeine Maschinenlehre (1862 und 1875. Bd. 1, Kap. 5: Dynamometer) Hammond, W. A. : The Dynamometer and Dynamograph of Mathieu. Q. J. of Psychological Medicine 2 (1868) 139 Poncelet, J. V. : Introduction à la Mécanique Industrielle (3ème éd., 1870) Broca, P. : Instructions générales pour les recherches anthropologiques à faire sur le vivant (2ème éd., 1879) Guerout, A. : Les dynamomètres. La Lumière Électrique, Nos 45-50 (1881) Richard, G. : Les Dynamomètres. La Lumière Électrique, Nos 24-33 (1882), 10 (1883), 40 (1884), 21 (1885), 12 (1888), 19 (1889) et 31 (1891) Jervis-Smith, F. J. : Dynamometers (1915) Benton, W. A. : The Early History of the Spring Balance. Tr. of the Newcomen Society 22 (1941) 65 Pearn, J. : Two Early Dynamometers. J. of the Neurological Sciences 37 (1978) 127 Hirschmüller, A. : Dynamometrie. Zur Messung der Körperkraft des Menschen im 19. Jahrhundert NTM International Journal of History & Ethics of Natural Sciences, Technology & Medicine 5 (1997) 104 Horne, D. and Talbot, E. : The History of the Régnier Dynamometer. Iron Grip Vol. 2, No 3 (July 2002) Savoysky, S. : Les planimètres. Arts mécaniques 23 (2002) 24-39 Web version (August 16, 2004) : http://serge.savoysky.pagesperso-orange.fr/Planimetres,%20v3%20(WEB).pdf Drechsler, S. and Haeberlin, B. : Cones, Disks, Wheels and Spheres for Area and Integration The Oughtred Society (Ed.): Proceedings IM 2011 (Cambridge, M.A., September 2011) 20