odontograph

[ oh-don-tuh-graf, -grahf ]

noun

1. an instrument for laying out the forms of gear teeth or ratchets.

Other Words From

• o·don·to·graph·ic [oh-don-t, uh, -, graf, -ik], adjective
• o·don·tog·ra·phy [oh-don-, tog, -r, uh, -fee], noun

Word History and Origins

Origin of odontograph¹

First recorded in 1855–60; odonto- + -graph

Example Sentences

An instrument much employed in the best practice to find the radius which will strike an arc of a circle approximating the true epicycloidal curve, and for finding at the same time the location of the centre wherefrom that curve should be struck, is found in the Willis’ odontograph.

From Project Gutenberg

Then place the graduated edge of the odontograph at d, and in such a position that the number and division found as already stated shall come precisely on the tangent line at d, and at the same time so set the curved edge h f c so that it shall be tangent to the tangent line, that is to say, the curved edge c h must just meet the tangent line at some one point, as at f in the figure.

From Project Gutenberg

If the Willis odontograph or the Robinson template odontograph be used the second set of lines will also be necessary.

From Project Gutenberg

Example.—What is the setting number on the odontograph for the flanks of a wheel to contain 12 teeth and gear with one having 24 teeth, the degree of curvature for the flanks being represented by 4 in the column of “Degree of flank curvature?”

From Project Gutenberg

For the face curve set the slant edge of the odontograph coincident with the radial line l, and in the table of centres for the faces of teeth, look down the column of 3-inch pitch, and opposite to 30 in the number of teeth column will be found the number 21, indicating that at 21 on the graduated edge of the odontograph, is the location of the centre wherefrom to strike the curve d for the face of the tooth, this location being denoted in the cut at r.

From Project Gutenberg