Definition

Adjective: 1. Equipped with gearing that reduces speed: Describes a machine, especially a lathe, that has a secondary gear system (back gears) to reduce the rotational speed of the spindle or output shaft from the higher speed of the driving pulley or motor. This provides greater torque and control for heavy or precise work. 2. Equipped with compound gearing for increased mechanical advantage: Describes a mechanism, such as in a crane's lifting system, that uses a specific arrangement of two pinions and two wheels in mesh. This compound gearing multiplies force, allowing heavy loads to be lifted with less input force.

Usage and Examples

• Describing a lathe:

  • The workshop purchased a double-geared lathe for machining large steel components.
  • A double-geared headstock allows the machinist to select very low speeds for threading.

• Describing a lifting mechanism:

  • The crane's double-geared hoist provided the necessary power to lift the concrete slab.
  • The mechanical advantage of the double-geared system made the manual winch surprisingly effective.

Advanced Usage and Technical Context

• "Back-geared" as a synonym in machining: In the context of lathes, "double-geared" is often synonymous with "back-geared." It refers to the engagement of a set of gears located behind the headstock to achieve speed reduction.
  • For this cut, you need to engage the double-geared drive to prevent chatter.

Variants and Related Words

• Back-geared (adj): Often used interchangeably with "double-geared" when describing lathes equipped with a speed-reducing gear train.
• Compound gearing (n): A general term for a gear system where multiple gears are arranged to achieve a specific speed reduction or mechanical advantage, of which a double-geared system is one type.

Synonyms

• Reduced-gear
• Two-stage geared (in specific technical contexts)

Notes on Meaning

• The term is highly technical and specific to mechanical and machining fields. Its primary function is to indicate either speed reduction (for control and power in lathes) or force multiplication (for lifting in mechanisms like cranes). The exact meaning is determined by the machine being described.

Adjective

1. (of a lathe) equipped with gearing for reducing the speed of the spindle from that of the driving pulley
   • a back-geared lathe
2. equipped with compound gearing consisting of 2 pinions and 2 wheels in mesh to increase the mechanical advantage
   • the double-geared lifting mechanism of a crane