Ratchet - Revision history

DT Online at 13:43, 28 August 2016

2016-08-28T13:43:39Z

← Older revision		Revision as of 13:43, 28 August 2016
Line 23:		Line 23:
	\|-		\|-
	\| [https://youtu.be/rKYTr9NjgOA '''Ratchet Wheel'''] - ratchet wheel can rotate only anticlockwise because reverse rotation is prevented by flat spring.		\| [https://youtu.be/rKYTr9NjgOA '''Ratchet Wheel'''] - ratchet wheel can rotate only anticlockwise because reverse rotation is prevented by flat spring.
	\| {{#ev:youtube\|rKYTr9NjgOA\|200x200\|right\|\|frame\|loop=1&autoplay=1&playlist=rKYTr9NjgOA}}		\| {{#ev:youtube\|rKYTr9NjgOA\|200x200\|right\|\|frame\|loop=1&autoplay=0&playlist=rKYTr9NjgOA}}
	\| [https://youtu.be/V4yxGR4d7l8 '''Ratchet Mechanism'''] being used to convert the continuous rotary motion of a drive shaft into the intermittent rotary motion of a driven shaft such that by flicking over the blue pawl the motion direction of the driven shaft can be changed without changing the input motion direction		\| [https://youtu.be/V4yxGR4d7l8 '''Ratchet Mechanism'''] being used to convert the continuous rotary motion of a drive shaft into the intermittent rotary motion of a driven shaft such that by flicking over the blue pawl the motion direction of the driven shaft can be changed without changing the input motion direction
	\| {{#ev:youtube\|V4yxGR4d7l8\|200x200\|right\|\|frame\|loop=1&autoplay=1&playlist=V4yxGR4d7l8}}		\| {{#ev:youtube\|V4yxGR4d7l8\|200x200\|right\|\|frame\|loop=1&autoplay=0&playlist=V4yxGR4d7l8}}
	\|-		\|-
	\| [https://youtu.be/fC8D_KzMGrk '''Pendulum Clock Escapement'''] - the gravity pendulum performs a '''[[Types of Motion\|harmonic angular oscillation]]''' and the ratchet wheel tends to rotate clockwise due to the weight which is suspended by a cord wound around its shaft. The anchor rocks with the pendulum and allows the wheel to rotate only two teeth during each oscillation - the characteristic ‘Tick-tock’ sound is caused when the anchor collides the wheel teeth. The mechanism is used in pendulum clocks where the wheel motion is transmitted to hands through a gear train to show time. Note that the weight driven wheel also transfers energy to the pendulum ''(timekeeper)'' to replace the energy lost to friction during its cycle and keeps the pendulum oscillating.		\| [https://youtu.be/fC8D_KzMGrk '''Pendulum Clock Escapement'''] - the gravity pendulum performs a '''[[Types of Motion\|harmonic angular oscillation]]''' and the ratchet wheel tends to rotate clockwise due to the weight which is suspended by a cord wound around its shaft. The anchor rocks with the pendulum and allows the wheel to rotate only two teeth during each oscillation - the characteristic ‘Tick-tock’ sound is caused when the anchor collides the wheel teeth. The mechanism is used in pendulum clocks where the wheel motion is transmitted to hands through a gear train to show time. Note that the weight driven wheel also transfers energy to the pendulum ''(timekeeper)'' to replace the energy lost to friction during its cycle and keeps the pendulum oscillating.
	\| {{#ev:youtube\|fC8D_KzMGrk\|200x200\|right\|\|frame\|loop=1&autoplay=1&playlist=fC8D_KzMGrk}}		\| {{#ev:youtube\|fC8D_KzMGrk\|200x200\|right\|\|frame\|loop=1&autoplay=0&playlist=fC8D_KzMGrk}}
	\| [https://youtu.be/bAL_nWjuhOI '''Bicycle Free-Wheel.'''] - sprocket receives motion from the pedaling bicyclist but the hub rotates only when the sprocket rotates clockwise and clockwise rotation of the hub has no influence to the sprocket. The pawl is always pressed toward the sprocket's teeth by a spring. In practice two pawls are used.		\| [https://youtu.be/bAL_nWjuhOI '''Bicycle Free-Wheel.'''] - sprocket receives motion from the pedaling bicyclist but the hub rotates only when the sprocket rotates clockwise and clockwise rotation of the hub has no influence to the sprocket. The pawl is always pressed toward the sprocket's teeth by a spring. In practice two pawls are used.
	\| {{#ev:youtube\|bAL_nWjuhOI\|200x200\|right\|\|frame\|loop=1&autoplay=1&playlist=bAL_nWjuhOI}}		\| {{#ev:youtube\|bAL_nWjuhOI\|200x200\|right\|\|frame\|loop=1&autoplay=0&playlist=bAL_nWjuhOI}}
	\|}		\|}

DT Online at 16:55, 26 August 2016

2016-08-26T16:55:23Z

← Older revision		Revision as of 16:55, 26 August 2016
Line 29:		Line 29:
	\| [https://youtu.be/fC8D_KzMGrk '''Pendulum Clock Escapement'''] - the gravity pendulum performs a '''[[Types of Motion\|harmonic angular oscillation]]''' and the ratchet wheel tends to rotate clockwise due to the weight which is suspended by a cord wound around its shaft. The anchor rocks with the pendulum and allows the wheel to rotate only two teeth during each oscillation - the characteristic ‘Tick-tock’ sound is caused when the anchor collides the wheel teeth. The mechanism is used in pendulum clocks where the wheel motion is transmitted to hands through a gear train to show time. Note that the weight driven wheel also transfers energy to the pendulum ''(timekeeper)'' to replace the energy lost to friction during its cycle and keeps the pendulum oscillating.		\| [https://youtu.be/fC8D_KzMGrk '''Pendulum Clock Escapement'''] - the gravity pendulum performs a '''[[Types of Motion\|harmonic angular oscillation]]''' and the ratchet wheel tends to rotate clockwise due to the weight which is suspended by a cord wound around its shaft. The anchor rocks with the pendulum and allows the wheel to rotate only two teeth during each oscillation - the characteristic ‘Tick-tock’ sound is caused when the anchor collides the wheel teeth. The mechanism is used in pendulum clocks where the wheel motion is transmitted to hands through a gear train to show time. Note that the weight driven wheel also transfers energy to the pendulum ''(timekeeper)'' to replace the energy lost to friction during its cycle and keeps the pendulum oscillating.
	\| {{#ev:youtube\|fC8D_KzMGrk\|200x200\|right\|\|frame\|loop=1&autoplay=1&playlist=fC8D_KzMGrk}}		\| {{#ev:youtube\|fC8D_KzMGrk\|200x200\|right\|\|frame\|loop=1&autoplay=1&playlist=fC8D_KzMGrk}}
	\| [https://youtu.be/bAL_nWjuhOI '''Bicycle Free-Wheel.'''] -sprocket receives motion from the pedaling bicyclist but the hub rotates only when the sprocket rotates clockwise and clockwise rotation of the hub has no influence to the sprocket. The pawl is always pressed toward the sprocket's teeth by a spring. In practice two pawls are used.		\| [https://youtu.be/bAL_nWjuhOI '''Bicycle Free-Wheel.'''] - sprocket receives motion from the pedaling bicyclist but the hub rotates only when the sprocket rotates clockwise and clockwise rotation of the hub has no influence to the sprocket. The pawl is always pressed toward the sprocket's teeth by a spring. In practice two pawls are used.
	\| {{#ev:youtube\|bAL_nWjuhOI\|200x200\|right\|\|frame\|loop=1&autoplay=1&playlist=bAL_nWjuhOI}}		\| {{#ev:youtube\|bAL_nWjuhOI\|200x200\|right\|\|frame\|loop=1&autoplay=1&playlist=bAL_nWjuhOI}}
	\|}		\|}

DT Online: Added animations

2016-08-26T16:54:34Z

Added animations

← Older revision		Revision as of 16:54, 26 August 2016
Line 17:		Line 17:

	=====Animations=====		=====Animations=====

			* Examples from '''[[2100 Animated Mechanical Mechanisms\|Nguyen Duc Thang's]]''' YouTube Channel '''[[2100 Animated Mechanical Mechanisms]]'''

	{\|		{\|
	\|-		\|-
	\| ~~'''[[2100 Animated Mechanical Mechanisms\|Nguyen Duc Thang's]]''' example of a~~ [https://youtu.be/rKYTr9NjgOA '''Ratchet Wheel'''] - ratchet wheel can rotate only anticlockwise because reverse rotation is prevented by flat spring.		\| [https://youtu.be/rKYTr9NjgOA '''Ratchet Wheel'''] - ratchet wheel can rotate only anticlockwise because reverse rotation is prevented by flat spring.
	\| {{#ev:youtube\|rKYTr9NjgOA\|~~240x240~~\|right\|\|frame\|loop=1&autoplay=1&playlist=rKYTr9NjgOA}}		\| {{#ev:youtube\|rKYTr9NjgOA\|200x200\|right\|\|frame\|loop=1&autoplay=1&playlist=rKYTr9NjgOA}}
			\| [https://youtu.be/V4yxGR4d7l8 '''Ratchet Mechanism'''] being used to convert the continuous rotary motion of a drive shaft into the intermittent rotary motion of a driven shaft such that by flicking over the blue pawl the motion direction of the driven shaft can be changed without changing the input motion direction
			\| {{#ev:youtube\|V4yxGR4d7l8\|200x200\|right\|\|frame\|loop=1&autoplay=1&playlist=V4yxGR4d7l8}}
	\|-		\|-
	\| '''[[2100 Animated Mechanical Mechanisms\|Nguyen Duc Thang's]]''' example of a [https://youtu.be/V4yxGR4d7l8 '''Ratchet Mechanism'''] being used to convert the continuous rotary motion of a drive shaft into the intermittent rotary motion of a driven shaft such that by flicking over the blue pawl the motion direction of the driven shaft can be changed without changing the input motion direction		\| [https://youtu.be/fC8D_KzMGrk '''Pendulum Clock Escapement'''] - the gravity pendulum performs a '''[[Types of Motion\|harmonic angular oscillation]]''' and the ratchet wheel tends to rotate clockwise due to the weight which is suspended by a cord wound around its shaft. The anchor rocks with the pendulum and allows the wheel to rotate only two teeth during each oscillation - the characteristic ‘Tick-tock’ sound is caused when the anchor collides the wheel teeth. The mechanism is used in pendulum clocks where the wheel motion is transmitted to hands through a gear train to show time. Note that the weight driven wheel also transfers energy to the pendulum ''(timekeeper)'' to replace the energy lost to friction during its cycle and keeps the pendulum oscillating.
	~~\| {{#ev:youtube\|V4yxGR4d7l8\|240x240\|right\|\|frame\|loop=1&autoplay=1&playlist=V4yxGR4d7l8}}~~		\| {{#ev:youtube\|fC8D_KzMGrk\|200x200\|right\|\|frame\|loop=1&autoplay=1&playlist=fC8D_KzMGrk}}
	\|-		\| [https://youtu.be/bAL_nWjuhOI '''Bicycle Free-Wheel.'''] -sprocket receives motion from the pedaling bicyclist but the hub rotates only when the sprocket rotates clockwise and clockwise rotation of the hub has no influence to the sprocket. The pawl is always pressed toward the sprocket's teeth by a spring. In practice two pawls are used.
	~~\| '''[[2100 Animated Mechanical Mechanisms\|Nguyen Duc Thang's]]''' example of a~~ [https://youtu.be/fC8D_KzMGrk '''Pendulum Clock ~~Escapment~~'''] - the gravity pendulum performs a '''[[Types of Motion\|harmonic angular oscillation]]''' and the ratchet wheel tends to rotate clockwise due to the weight which is suspended by a cord wound around its shaft. The anchor rocks with the pendulum and allows the wheel to rotate only two teeth during each oscillation - the characteristic ‘Tick-tock’ sound is caused when the anchor collides the wheel teeth. The mechanism is used in pendulum clocks where the wheel motion is transmitted to hands through a gear train to show time. Note that the weight driven wheel also transfers energy to the pendulum ''(timekeeper)'' to replace the energy lost to friction during its cycle and keeps the pendulum oscillating.		\| {{#ev:youtube\|bAL_nWjuhOI\|200x200\|right\|\|frame\|loop=1&autoplay=1&playlist=bAL_nWjuhOI}}
	\| {{#ev:youtube\|fC8D_KzMGrk\|~~240x240~~\|right\|\|frame\|loop=1&autoplay=1&playlist=fC8D_KzMGrk}}
	\|}		\|}

DT Online: Added Template and Animation

2016-08-26T08:09:47Z

Added Template and Animation

← Older revision		Revision as of 08:09, 26 August 2016
Line 1:		Line 1:
	[[File:RatchetPawl.png\|300px\|right]]		[[File:RatchetPawl.png\|300px\|right]]
			__TOC__


			=====Description=====

	A [https://en.wikipedia.org/wiki/Ratchet_%28device%29 '''Ratchet'''] mechanism allows movement in one direction only.		A [https://en.wikipedia.org/wiki/Ratchet_%28device%29 '''Ratchet'''] mechanism allows movement in one direction only.


			=====Features and Applications=====

	In the illustration, the '''Ratchet Wheel''' lifts the '''Pawl''' as it rotates anti-clockwise but clockwise rotation is stopped by it. Such a system is used in '''[[Windlass\|Winches]]''' to allow loads to be lifted up without slipping down again. The '''Ratchet Wheel''' could be fixed to the '''Winch''' shaft via a '''[[Keys, Keyways and Splines\|Key]]''' as shown. Alternatively, use of a square or hexagonal winch shaft would ensure it rotates with the '''Ratchet'''.		In the illustration, the '''Ratchet Wheel''' lifts the '''Pawl''' as it rotates anti-clockwise but clockwise rotation is stopped by it. Such a system is used in '''[[Windlass\|Winches]]''' to allow loads to be lifted up without slipping down again. The '''Ratchet Wheel''' could be fixed to the '''Winch''' shaft via a '''[[Keys, Keyways and Splines\|Key]]''' as shown. Alternatively, use of a square or hexagonal winch shaft would ensure it rotates with the '''Ratchet'''.
Line 7:		Line 14:

	A similar idea can be used to create a '''Linear Ratchet''' which allows motion in one direction but not the other. A '''Pawl''' type mechanism allows each squeeze of a trigger to tighten a '''[[Bar Clamp]]''' for example. They are found also as '''Quick Release Mechanisms''' on some '''[[Carpenters Vice\|Wood VIces]]''' and are the basis of the humble [https://en.wikipedia.org/wiki/Cable_tie '''Cable Tie'''],		A similar idea can be used to create a '''Linear Ratchet''' which allows motion in one direction but not the other. A '''Pawl''' type mechanism allows each squeeze of a trigger to tighten a '''[[Bar Clamp]]''' for example. They are found also as '''Quick Release Mechanisms''' on some '''[[Carpenters Vice\|Wood VIces]]''' and are the basis of the humble [https://en.wikipedia.org/wiki/Cable_tie '''Cable Tie'''],


			=====Animations=====

	{\|		{\|
	\|-		\|-
	\| ~~See~~ '''[[2100 Animated Mechanical Mechanisms\|Nguyen Duc Thang's]]''' example of a [https://youtu.be/V4yxGR4d7l8 '''Ratchet Mechanism'''] being used to convert the continuous rotary motion of a drive shaft into the intermittent rotary motion of a driven shaft such that by flicking over the blue pawl the motion direction of the driven shaft can be changed without changing the input motion direction		\| '''[[2100 Animated Mechanical Mechanisms\|Nguyen Duc Thang's]]''' example of a [https://youtu.be/rKYTr9NjgOA '''Ratchet Wheel'''] - ratchet wheel can rotate only anticlockwise because reverse rotation is prevented by flat spring.
			\| {{#ev:youtube\|rKYTr9NjgOA\|240x240\|right\|\|frame\|loop=1&autoplay=1&playlist=rKYTr9NjgOA}}
			\|-
			\| '''[[2100 Animated Mechanical Mechanisms\|Nguyen Duc Thang's]]''' example of a [https://youtu.be/V4yxGR4d7l8 '''Ratchet Mechanism'''] being used to convert the continuous rotary motion of a drive shaft into the intermittent rotary motion of a driven shaft such that by flicking over the blue pawl the motion direction of the driven shaft can be changed without changing the input motion direction
	\| {{#ev:youtube\|V4yxGR4d7l8\|240x240\|right\|\|frame\|loop=1&autoplay=1&playlist=V4yxGR4d7l8}}		\| {{#ev:youtube\|V4yxGR4d7l8\|240x240\|right\|\|frame\|loop=1&autoplay=1&playlist=V4yxGR4d7l8}}
			\|-
			\| '''[[2100 Animated Mechanical Mechanisms\|Nguyen Duc Thang's]]''' example of a [https://youtu.be/fC8D_KzMGrk '''Pendulum Clock Escapment'''] - the gravity pendulum performs a '''[[Types of Motion\|harmonic angular oscillation]]''' and the ratchet wheel tends to rotate clockwise due to the weight which is suspended by a cord wound around its shaft. The anchor rocks with the pendulum and allows the wheel to rotate only two teeth during each oscillation - the characteristic ‘Tick-tock’ sound is caused when the anchor collides the wheel teeth. The mechanism is used in pendulum clocks where the wheel motion is transmitted to hands through a gear train to show time. Note that the weight driven wheel also transfers energy to the pendulum ''(timekeeper)'' to replace the energy lost to friction during its cycle and keeps the pendulum oscillating.
			\| {{#ev:youtube\|fC8D_KzMGrk\|240x240\|right\|\|frame\|loop=1&autoplay=1&playlist=fC8D_KzMGrk}}
	\|}		\|}

			{{Mechanisms Buyers Guide}}

	[[Category:Mechanisms]]		[[Category:Mechanisms]]

DT Online: Added animation

2016-08-25T20:02:12Z

Added animation

← Older revision		Revision as of 20:02, 25 August 2016
Line 7:		Line 7:

	A similar idea can be used to create a '''Linear Ratchet''' which allows motion in one direction but not the other. A '''Pawl''' type mechanism allows each squeeze of a trigger to tighten a '''[[Bar Clamp]]''' for example. They are found also as '''Quick Release Mechanisms''' on some '''[[Carpenters Vice\|Wood VIces]]''' and are the basis of the humble [https://en.wikipedia.org/wiki/Cable_tie '''Cable Tie'''],		A similar idea can be used to create a '''Linear Ratchet''' which allows motion in one direction but not the other. A '''Pawl''' type mechanism allows each squeeze of a trigger to tighten a '''[[Bar Clamp]]''' for example. They are found also as '''Quick Release Mechanisms''' on some '''[[Carpenters Vice\|Wood VIces]]''' and are the basis of the humble [https://en.wikipedia.org/wiki/Cable_tie '''Cable Tie'''],

			{\|
			\|-
			\| See '''[[2100 Animated Mechanical Mechanisms\|Nguyen Duc Thang's]]''' example of a [https://youtu.be/V4yxGR4d7l8 '''Ratchet Mechanism'''] being used to convert the continuous rotary motion of a drive shaft into the intermittent rotary motion of a driven shaft such that by flicking over the blue pawl the motion direction of the driven shaft can be changed without changing the input motion direction
			\| {{#ev:youtube\|V4yxGR4d7l8\|240x240\|right\|\|frame\|loop=1&autoplay=1&playlist=V4yxGR4d7l8}}
			\|}

	[[Category:Mechanisms]]		[[Category:Mechanisms]]

DT Online: Created Article

2015-11-08T18:09:07Z

Created Article

New page

[[File:RatchetPawl.png|300px|right]]
A [https://en.wikipedia.org/wiki/Ratchet_%28device%29 '''Ratchet'''] mechanism allows movement in one direction only.

In the illustration, the '''Ratchet Wheel''' lifts the '''Pawl''' as it rotates anti-clockwise but clockwise rotation is stopped by it. Such a system is used in '''[[Windlass|Winches]]''' to allow loads to be lifted up without slipping down again. The '''Ratchet Wheel''' could be fixed to the '''Winch''' shaft via a '''[[Keys, Keyways and Splines|Key]]''' as shown. Alternatively, use of a square or hexagonal winch shaft would ensure it rotates with the '''Ratchet'''.

A similar idea can be used to create a '''Linear Ratchet''' which allows motion in one direction but not the other. A '''Pawl''' type mechanism allows each squeeze of a trigger to tighten a '''[[Bar Clamp]]''' for example. They are found also as '''Quick Release Mechanisms''' on some '''[[Carpenters Vice|Wood VIces]]''' and are the basis of the humble [https://en.wikipedia.org/wiki/Cable_tie '''Cable Tie'''],

[[Category:Mechanisms]]