A Compendium of Mechanics, Or, Text Books for Engineers &C (Paperback)

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1824 edition. Excerpt: ...length is found by multiplying the thickness by 1.2. EXAMPLE. The thickness being 2 inches, what is the pitch and length? 2 X 2.1 3= 4.2 Pitch. 2 X 1.2 X 2.4 Length. Note. The breadth of the teeth, as commonly executed by the best Masters, seems to be from about twice to thrice the pitch. VELOCITY OF WHEELS. Wheels are for conveying motion to the different parts of a machine, at the same, or at a greater, or less velocity, as may be required.--When two wheels are in motion their teeth act on one another alternately, and consequently, if one of these wheels has 40 teeth, and the other 20 teeth, the one with 20-will turn twice upon its axis, for one revolution of the wheel with 40 teeth.--From this the Rule is taken, which is, --As the velocity required is to the number of teeth in the driver, so is the velocity xf the driver to the number of teeth in the driven. Note. To iind the proportion that the velocities of the wheels in a train should bear to one another, subtract theJess velocity from thegreater, and divide the remainder by the number of one less than the wheels in the train; the quotient will be the number rising in Arithmetical progression, from the least to the greamsbveloeity of the train: o; wheels. EXAMPLE I. What is the number of teeth in each of three wheels to produce 17 revolutions per minute, the driver having 107 teeth, and making 3 revolutions per minute? 17--9 14,, -J-= 7, therefore 3 10 17 are the velocities of the three wheels. What is the number of teeth in each of 7 wheels, to produce 1 revolution per minute, the driver having 25 teeth, and making 56 revolutions per minute? 56--1--55 7 _ l _ 6 = 'therefore 56 46 37 28 19 10 - progressional velocities. It will be observed that the last wheel, in...