Why return stroke is faster than cutting stroke?

The versatile nature of a machine gives a path to the operator to cut the gear teeth, splines, keyways etc. Due to linkage geometry, the return stroke is faster and hence this is known widely as the quick return mechanism. This is possible via a Whitworth link or slotted link.

What is the ratio between cutting stroke and return stroke?

Find the ratio of time of cutting stroke to time of return stroke. Explanation: Ratio of the time of cutting stroke to the time of return stroke for a crank and slotted lever quick return mechanism = (360-α)/α = (360-150)/150 = 1.4.

What is Whitworth quick return motion?

The Whitworth quick return mechanism converts rotary motion into reciprocating motion, but unlike the crank and slider, the forward reciprocating motion is at a different rate than the backward stroke. This mechanism is most commonly seen as the drive for a shaping machine.

What is the difference between crank and slotted lever and Whitworth quick return mechanism?

The difference between the crank and lever mechanism and Whitworth mechanism is that in whitworth mechanism the return stroke is faster than the forward stroke while in the crank and lever mechanism the forward stroke is of same speed as that of return stroke. 1) Slotted Bar. 3) Crank – It will rotate.

Which stroke is cutting stroke in shaper?

Forward stroke
Which stroke is cutting stroke in shaper? Explanation: Forward stroke is cutting stroke in shaper because only in forward stroke work-cutting is done. 8.

Why quick return is important in shaping?

Quick return is a common feature of tools in which the action is performed in only one direction of the stroke, such as shapers and powered saws, because it allows less time to be spent on returning the tool to its initial position.

How do you measure how long an effective stroke is?

In order to find the length of effective stroke R1R2, mark P1R1 = P2R2 = PR. The length of effective stroke is equal to 2 PD.

How does a quick return mechanism work?

Powered by a motor, the disc rotates and the arm follows in the same direction (linear and left-to-right, typically) but at a different speed. When the disc nears a full revolution, the arm reaches its furthest position and returns to its initial position at a quicker rate, hence its name.