Positive Return Cam
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- Title:
- Positive Return Cam
- Title (German):
- Ungleichseitig. Bogenfünfeck mit verstellb. Schleife
- Collection:
- Reuleaux Kinematic Mechanisms Collection
- Set:
- L. Positive Return Constant Breadth Cams
- Designer:
- Reuleaux, F. (Franz), 1829-1905
- Manufacturer:
- Gustav Voigt Werkstatt
- Date:
- 1882
- Country:
- Germany
- Voigt Catalog Model:
- L5
- File Name:
- L05.jpg
- Work Type:
- Mechanical model
- Materials/Techniques:
- cast iron and brass on wood pedestal
- Subject:
- Kinematics of Machinery
- Measurement:
- 200 x 88 (millimeters, width x depth)
290 x 117 x 203 (millimeters, width x depth x height) - Description:
- A cam is a kinematic pair in which one part is free to slide against the surface of another part. In the L series of models one part is rotated against a straight or curved surface forcing the latter to move in a horizontal or straight-line motion. The action is closed kinematically by using a curve of constant width between two surfaces separated by a constant distance. In model L-1, the former is a curved triangle known today as a Reuleaux Triangle [see model B-2] In Model L-1, the carved triangle is rotated about one of its vertices. This produces two phases of exact finite time dwell in the motion cycle. In model L-5 the rotor is a five-sided curved polygon of constant width. A screw allows the center of motion of the curved pentagon to be changed. The parallel guides are set to 45¼. Positive return cams were used in the control of valves in steam engines in the early 19th century. They are still used in modern machines to impose a given motion to a part during a machine cycle. Cams in general are used extensively in automotive engines. However cam contact is generally maintained with elastic springs instead of parallel guides. [Francis Moon 2003-07-01]
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.