back gear

American  

noun

1. (in a lathe) one of several gears for driving the headstock at various speeds.

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Other Word Forms

• backgeared adjective

Example Sentences

The steps of the cone should be so proportioned that the belt will shift from one to the other, and have the same degree of tension, while at the same time they should give a uniform graduation or variation of speed throughout, whether the lathe runs in single gear or with the back gear in.

From Project Gutenberg

The various motions of the machine are as follows: There are 16 speeds of work table, 8 with the single, and the same with the back gear.

From Project Gutenberg

Motion for the cone pulley a is received by pulleys b and is conveyed by belt to cone pulley c, which is provided with back gear, as shown; the driving spindle d drives the bevel pinion e, which gears with the bevel-wheel f, which drives the drill spindle g by means of a feather fitting in a keyway or spline that runs along that spindle.

From Project Gutenberg

The cone pulley a is provided with back gear b placed beneath it, the live spindle driving the drill spindle through the bevel gears c, one of which is fast upon a sleeve d through which the drill spindle e passes.

From Project Gutenberg

In this machine the motion for both drilling and turning is received by belt on the cone pulley shown on the right, which is provided with back gear similar to that of a lathe.

From Project Gutenberg