Parallel Stage of von Schönemann
- Title:
- Parallel Stage of von Schönemann
- Title (German):
- Unvollkommene Hebelparallelführung, Oberschalige Wage von Schönemann
- Collection:
- Reuleaux Kinematic Mechanisms Collection
- Set:
- T. Parallel Guide Mechanisms
- Designer:
- Reuleaux, F. (Franz), 1829-1905
- Manufacturer:
- Gustav Voigt Werkstatt
- Date:
- 1882
- Country:
- Germany
- Voigt Catalog Model:
- T4
- File Name:
- T04.jpg
- Work Type:
- Mechanical model
- Materials/Techniques:
- cast iron and brass on wood pedestal
- Subject:
- Kinematics of Machinery
- Measurement:
- 280 x 95 (millimeters, width x depth)
280 x 95 x 217 (millimeters, width x depth x height) - Description:
- The T series in the Voigt catalog constitute so-called parallel guide mechanisms. In contrast with the straight-line mechanisms in the S series, the parallel guides maintain zero rotational variation between links during motion. The models T-3 to T-8 incorporate horizontal stages as in weighing machines. In model T-4 two lever mechanisms (a smaller one above the lower lever) are coupled by three vertical links as well as through a ground link at their fulcrums. This is an example of a compound kinematic chain. Grübler published a criterion to determine the degrees of freedom for a set of n links and v joints and number of degrees of freedom F=3(n-1)-2r (See KMODDL Tutorial on Mobility (Grübler’s) criteria.) In model T-4, there are 8 cylindrical joints and 6 links (counting the grounded link) which gives F=-1. Since F=1 constitutes a perfect mechanism, the arrangement in T-4 is more like a structure. The special vertical and horizontal link allows small motions that keep the two stages parallel. A similar over-constrained mechanism is shown in Model T-6. [Francis Moon, 2004-07-00]
The 220 models in Cornell University’s Reuleaux Collection were built in the late 19th century to demonstrate the elements of machine motion, as theorized by the German engineer Franz Reuleaux. The University acquired the models in 1882 for use in teaching and research. The Reuleaux models are classified according to the alphanumeric schema employed in the catalog of the manufacturer, Gustav Voigt. The letter in a model's ID (e.g., B14 or S35) refers to a class of mechanism; the number is a specific instance of the class. This classification scheme is a simplified version of the taxonomy of machine elements elaborated in Reuleaux's work. - Repository:
- Sibley School of Mechanical and Aerospace Engineering, Cornell University
- Format:
- Image
- Rights:
- Photography credit: Jon Reis (www.jonreis.com). Jon Reis Photography grants Cornell University Libraries and the Cornell College of Engineering the rights to display copyrighted images of the Reuleux collection of kinetic machines on the Cornell University and National Science Digital Library web sites and for unlimited use in Cornell University Library publications for education purposes only. Rights for all other uses, including but not limited to, editorial, commercial, advertising, web use and display by third parties not affiliated with Cornell University are reserved by the photographer. The written permission of any copyright and other rights holders is required for distribution, reproduction, or other use that extends beyond what is authorized by fair use and other statutory exemptions. Responsibility for making an independent legal assessment of an item and securing any necessary permissions ultimately rests with persons desiring to use the item. For questions about this item or other items please contact the Physical Sciences Librarians at pslref@cornell.edu.