• WordNet 3.6
    • v ratchet move by degrees in one direction only "a ratcheting lopping tool"
    • n ratchet mechanical device consisting of a toothed wheel or rack engaged with a pawl that permits it to move in only one direction
    • ***
Webster's Revised Unabridged Dictionary
    • Ratchet A mechanism composed of a ratchet wheel, or ratch, and pawl. See Ratchet wheel, below, and 2d Ratch.
    • Ratchet A pawl, click, or detent, for holding or propelling a ratchet wheel, or ratch, etc.
    • ***
Century Dictionary and Cyclopedia
    • n ratchet A detent or pivoted piece designed to fit into the teeth of a ratchet-wheel, permitting the wheel to rotate in one direction, but not in the other. A similar device so arranged as to move the wheel is termed a pallet. (See ratchet-wheel click, 3, pawl, and detent.) Combined with the ratchet-wheel as a means of converting a reciprocating into a rotary motion, the ratchet appears in a number of tools and gives its name to each: as, the ratchet bed-key, etc.
    • n ratchet In printing, a notched straight blade of brass which rotates the pinions attached to the movable clamps of an electrotype plate mounted upon a block.
    • ***
Chambers's Twentieth Century Dictionary
    • ns Ratchet a bar acting on the teeth of a ratchet-wheel: a click or pall
    • ***


Webster's Revised Unabridged Dictionary
Properly a diminutive from the same word as rack,: cf. F. rochet,. See 2d Ratch Rack the instrument
Chambers's Twentieth Century Dictionary


In literature:

We think a ratchet wheel should not be employed with equidistant pallets.
"An Analysis of the Lever Escapement" by H. R. Playtner
Ratchet head 76 87.
"Practical Mechanics for Boys" by J. S. Zerbe
Its small, iron-ratcheted, wooden windlass extended along the top rail of the balustrade across one of the galerie's ends.
"Bonaventure" by George Washington Cable
One pair of dogs or andirons has ratchets on which supplementary bars were placed.
"Chats on Household Curios" by Fred W. Burgess
They went out on the other platform and kicked the ratchet out and let the wheel spin.
"Roy Blakeley's Camp on Wheels" by Percy Keese Fitzhugh
Press the ratchet down three times!
"Evening Dress" by W. D. Howells
Much small fry is roasted with a ratchet-wheel and spit.
"Pilgrimage from the Alps to the Tiber" by James Aitken Wylie
A ratchet prevents the arbor from being turned backwards by the spring.
"How it Works" by Archibald Williams
Asher increased the pressure of his ratchet trigger.
"Astounding Stories of Super-Science, June, 1930" by Various
Some took my patented ratchet extension.
"The Trouble with Telstar" by John Berryman
A ratchet-wheel is needed for this metaphor.
"When Ghost Meets Ghost" by William Frend De Morgan
He swirled about it, and his feet came off the ratchets.
"Harper's Round Table, October 22, 1895" by Various
As they watched, the superconducting coil ratcheted increasingly larger bursts of energy into the accelerator, pumping it up.
"Project Cyclops" by Thomas Hoover
Hundreds of little gears and ratchets and rods spilled out of it.
"Makers" by Cory Doctorow
If the ratchet of the maintaining power be of brass it should not be oiled; while if it is of steel oil should be applied.
"Friction, Lubrication and the Lubricants in Horology" by William T. Lewis
They are also sometimes called Gabriel or Gabble Ratchet.
"Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 4" by Various
The drill-bar is rotated by means of a ratchet operated by a spiral groove in the shield of the machine.
"Report of the Hoosac Tunnel and Troy and Greenfield Railroad, by the Joint Standing Committee of 1866." by Tappan Wentworth
This can be used on a rod, and put into and out of gear by a ratchet.
"Encyclopaedia Britannica, 11th Edition, Volume 14, Slice 1" by Various
Ratchet wheel Roue a cliquet.
"English-French and French-English dictionary of the motor car, cycle, and boat" by Frederick Lucas
The upper engages the ratchet of the cylinder when the revolution begins.
"The Modern American Pistol and Revolver" by A. C. Gould

In news:

Innovative Products of America introduces smooth-action Palm Ratchets.
Ratcheting swivel buckles offer flexibility for a great fit and fast adjustments.
EMD markets new growth promoter product called Ratchet .
A new postemerge product for corn and soybeans called Ratchet is available from EMD Crop Bioscience.
Ratchet is a growth promoter to help increase yields.
Lowell's Hi-Vis Double Shot™ Ratchet Wrenches are hard to lose and easy to find.
Ratchet 's Recent Photos and Stories.
' Ratchet ,' 'Borderlands' two fairly fun SciFi games.
The 21 Most Ratchet Women of Black Reality TV.
Barack Obama Brings Back the 'Liberal Ratchet '.
Duo try to sneak ratchet wrenches out of store.
A woman and an accomplice were caught trying to shoplift ratchet wrenches from a local discount store, lawmen say.
DMX's Ratchet Christmas Carol Remix.
Ratchet Up Fruits & Veggies.
Evelyn Lozada's Ratchet Attitude Sparks Online Boycott Petition.

In science:

The proposed system is in many ways analogous to a quantum ratchet in which an asymmetric potential can be used to induce directional particle flow through a tunnelling barrier (Linke et al., 1999).
Comment on Book Review of `Quantum Evolution' (Johnjoe McFadden) by Mathew J. Donald
For the integral in Eq. (25), which determines the ratchet current I0 , the relevant times are shorter than for the other integrals: t ∼ τ /ρ ∼ RQC .
Tunnel junction as a noise probe
In contrast, the ratchet effect, which is an odd effect, vanishes.
Tunnel junction as a noise probe
Only finite duration of the current pulse (finite τs ) can lead to an odd effect (ratchet voltage V0 as an example).
Tunnel junction as a noise probe
Asymmetry of shot noise results in asymmetry of the I V curve: the shift of the conductance minimum from the zero bias and the ratchet effect, which have been observed experimentally7,8 .
Tunnel junction as a noise probe
Ratchets are simple models of molecular motors, out of equilibrium systems with directed dissipative transport in the absence of any external bias.
The effective temperature
Kolton showed that the rectified transverse velocity of a driven particle in a geometric ratchet is equivalent to the response of a 1d flashing ratchet at a drive-dependent Teff , as defined from the generalized Einstein relation [131].
The effective temperature
Puglisi, The Ratchet effect in an ageing glass, J.
The effective temperature
Tierno, P., Reddy, S.V., Roper, M.G., Johansen, T.H., and Fischer, T.M. (2008). Transport and Separation of Biomolecular Cargo on Paramagnetic Colloidal Particles in a Magnetic Ratchet. J.
Field-control, phase-transitions, and life's emergence
Giant Transversal Particle Diffusion in a Longitudinal Magnetic Ratchet.
Field-control, phase-transitions, and life's emergence
Yu and Oster have developed a model that allow two parallel paths- one of these is based essentially on a Brownian ratchet mechanism whereas the other utilizes a power stroke.
Template-directed biopolymerization: tape-copying Turing machines
Not all kinetic models explicitly assume either the power stroke or the Brownian ratchet mechanism.
Template-directed biopolymerization: tape-copying Turing machines
Spirin, The ribosome as a conveying thermal ratchet machine, J.
Template-directed biopolymerization: tape-copying Turing machines
Devised as a pedagogical illustration of the Brownian ratchet mechanism, Parrondo’s games are coin flipping games with an apparently paradoxical property that alternating plays of two losing games produce a winning game.
One Dimensional Asynchronous Cooperative Parrondo's Games
The results are illustrated on the problem of the rocking ratchet.
Drift by Dichotomous Markov Noise