FIELD OF INVENTION

The invention relates to an innovative reciprocating mechanism. The present invention borrows the concept of Rack and Pinion arrangement but unlike the rack and pinion arrangement which converts the rotary motion into linear motion, the present invention converts the rotary motion into reciprocating motion, by use of rack and segmented gears. The present reciprocating mechanism has less number of moving parts when compared to other mechanisms. The present invention has reduced assembly time, simplified manufacturing process, reduced power loss, reduced weight. Moreover segmented gears are used for producing the reciprocating motion hence there is a reduced power loss, increased reliability and reduced maintenance. This mechanism can be used in mlling machines, shaper machines, de husking machinery etc.

BACKGROUND

Reciprocating motion, also called reciprocation, is a repetitive up-and-down or back-and-forth motion, it is found in a wide range of mechanisms, including reciprocating engines and pumps, oscillators etc. Reciprocating motion is obtained using pneumatic, hydraulic, and electric linear actuators. Reciprocating motion is also achieved using rack and pinion, and cams. Historically a number of machines have been operated very successfully using specially developed mechanisms. Although many reciprocating mechanism exist, they are generally used for converting rotary motion into linear motion. Further, most of them have drawbacks such as high slippage rate, multiple moving parts and hence increased amount of friction leading to power loss. Moreover, they are difficult to maintain and operate, in the present invention the drawbacks are addressed and minimised by use of a

PRIOR ART

This invention seeks to enlarge the scope of use of this combination of rack and segmented gears in machines used for milling, de husking of grains, shapers etc.

USPTO Patent No. 6,474,287 relates to a Reciprocating mechanism and engine including wherein a reciprocating mechanism for use in an engine comprises a reciprocating member which is movable in a substantially linear reciprocating direction between two ends of travel, a piston provided on the reciprocating member, and a constant breadth cam and follower, the follower being coupled directly to the reciprocating member to translate linear movement of the reciprocating member into rotary motion of the cam, and the mechanism being such that movement of the reciprocating member at the two ends of its travel is reversed in dependence upon the rotation of the cam, the follower lying to the side of the piston bore and the piston being rigidly mounted to the reciprocating member. This invention is used in pistons and engines and limited in scope. The present invention seeks to do away with such limitations and is a mechanism that can be used across all fields wherein the rotary motion is converted into a reciprocating motion. In the present invention, the rotary motion is being converted into reciprocating motion.

Scotch Yoke Mechanism. Rapid

The Scotch yoke is a mechanism for converting linear motion of a slider into rotational motion or vice-versa. The piston or other reciprocating part is directly coupled to a sliding yoke with a slot that engages a pin on the rotating part. The shape of the motion of the piston is a pure sine wave over time given a constant rotational speed. However, the drawback with this mechanism is the rapid wear of the slot in the yoke caused by sliding friction and high contact pressures. Increased heat loss during combustion due to extended dwell at top dead center offsets any constant volume combustion improvements in real engines. Lesser percentage of the time spent at bottom dead center reducing blow down time for two stroke engines, when compared with a conventional piston and crankshaft mechanism.

Offset Slider Crank

The offset slider crank produces a (working stroke time/return stroke time) ratio greater than unity based on the rotation direction and degree of offset. With no offset and a relatively long connecting link the ratio is unity. There is an advantage with having a faster return stroke in that this motion does no useful work and takes up valuable time. However the drawbacks with this mechanism are that due to high friction on the contacting surfaces, wear and tear is high and Balancing of sliding mass is difficult.

Ratchet mechanisnn

A wheel with suitably shaped teeth, receiving an intermittent circular motion from an oscillating member, is a ratchet wheel. In figure 3, 'A' is the ratchet wheel, and 'B' is an oscillating link. Attached to B is a pawl which is a link designed to engage with the ratchet teeth to prevent the wheel from moving in one direction. This mechanism has a supplementary pawl at 'D'. When the link B moves in a counter clockwise direction, the pawl 'C pushes the wheel through a partial rotation. When the link B moves clockwise, the pawl C slides over the points of the teeth while the wheel remains at rest because of the fixed pawl D. The amount of backward motion possible varies with the pitch of the teeth. The smaller the teeth, the smaller the backward motion. The contact surfaces of wheel and pawl should be inclined so they don't disengage under pressure. However, the drawbacks that are the biggest disadvantages of the ratchet mechanisms is that for the pawl to move from one tooth and engage the next tooth, the handle has to turn by an angle of typically 15-20 degrees. In addition, since the teeth are inclined, the backward motion required to engage a tooth starting from the preceding tooth is larger than the effective forward motion to turn the ratchet wheel, and thus additional "dead" space is needed. If there is no adequate space for such a manipulation, the operation of using the ratchet cannot be performed.

The Shaper Mechanism

Variations of this mechanism were universally used for providing the cutting motion of shaping machines. Again this mechanism has the advantage of a quick return cycle. This mechanism is a derivation of the offset slider mechanism. However, the drawbacks include possible friction clutch wear.

Whitworth Quick Return Mechanism

This is another variation of the shaper mechanism providing slightly different motion characteristics and a different geometry as shown in figure 5. However, the drawbacks are many and requires the operator to adjust the crankpin, i.e. the stroke adjustment, inside the machine.

Rack and pinion

A rack and pinion is a type of linear actuator that comprises a pair of gears which convert rotational motion into linear motion. The circular pinion engages teeth on a linear "gear" bar-the rack. Rotational motion applied to the pinion will cause the rack to move to the side, up to the limit of its travel. However, the advantage is that because of the simplicity of the system, it requires fewer parts to function properly. However, this places a greater strain on the individual parts, and the wear can cause leakage, requiring replacement of the rack assembly. Greater force given to the system can cause it to wear out much more quickly. Hence the mechanism is less durable. Due to the simpler construction and reduced number of parts, more noise and vibration results.

OBJECTIVES OF THE INVENTION:

The objective of this invention is to provide an improved and innovative reciprocating mechanism. Yet another objective of the invention is to provide a reciprocating mechanism which does not need linkages unlike traditional ones so as to reduce the number of moving parts and decrease the assembly time. Another objective of the invention is to reduce power and frictional loss and to reduce the maintenance. Still another objective of the invention is to provide reciprocating motion manually or automatically according to the user's requirement.

The present invention aims at minimising the aforementioned drawback and it basically involves conversion of rotary motion, produced by .a prewheel or any other suitable elements such as an electric motor etc., into reciprocating motion of the Reciprocating member, by using segmented gear and rack arrangements.

SCOPE OF THIS INVENTION

1. Less amount of slippage when compared to other types of reciprocating mechanism.

2. The present invention has less number of moving parts and hence there is part-count reduction.

3. Invention is maintenance free compared to other mechanisms used. Only needs lubrication.

4. The present invention can work manually or automatically according to the industry requirement.

5. The present invention can run at any speed with all types of rotating mechanisms makes it more convenient for use.

6. Power loss is reduced dramatically due to the usage of gears for power transmission.

7. Friction is comparatively less because number of moving parts are less. So more input power will be converted to work.

8. The present invention has reduced wear, reduced weight.

The present invention has reduced assembly time, and simplified manufacturing processes

BRIEF DESCRIPTION OF THE DRAWINGS

In Figure 1: The Scotch yoke is a mechanism for converting linear motion of a slider into a rotational motion or vice-versa. The piston or other reciprocating part is directly coupled to a sliding yoke with a slot that engages a pin on the rotating part. The shape of the motion of the piston is a pure sine wave over time given a constant rotational speed.

In Figure 2: The offset slider crank produces a (working stroke time/return stroke time) ratio greater than unity based on the rotation direction and degree of offset. With no offset and a relatively long connecting link the ratio is unity. There is an advantage with having a faster return stroke.

In Figure 3: A wheel with suitably shaped teeth, receiving an intermittent circular motion from an oscillating member, is a ratchet wheel. 'A' is the ratchet wheel, and 'B' is an oscillating link. Attached to B is a pawl which is a link designed to engage with the ratchet teeth to prevent the wheel from moving in one direction. This mechanism has a supplementary pawl at 'D'. When the link B moves in a counter clockwise direction, the pawl 'C pushes the wheel through a partial rotation. When the link B moves clockwise, the pawl C slides over the points of the teeth while the wheel remains at rest because of the fixed pawl D. The amount of backward motion possible varies with the pitch of the teeth. The smaller the teeth, the smaller the backward motion. The contact surfaces of wheel and pawl should be inclined so they don't disengage under pressure.

In Figure 4: Variations of this mechanism were universally used for providing the cutting motion of shaping machines. Again this mechanism has the advantage of a quick return cycle. This mechanism is a derivation of the offset slider mechanism.

In Figure 5: This is another variation of the shaper mechanism providing slightly different motion characteristics and a different geometry as shown in figure 5.

In Figure 6: A rack and pinion is a type of linear actuator that comprises a pair of gears which convert rotational motion into linear motion. The circular pinion engages teeth on a linear "gear" bar-the rack. Rotational motion applied to the pinion will cause the rack to move to the side, up to the limit of its travel.

In figure.7 : (1) Corresponds to Allen key on the first gear and (2) corresponds to the first segmented gear.

In figure.8: (3) Corresponds to Allen key on the second gear and (4) corresponds to the second segmented gear.

In figure.9: (5) Corresponds to the shaft. The numbers (12) & (13) corresponds to the position where the bearings are kept so as to aide in smooth rotation of shaft.

In figure.10: The numbers (7) & (8) corresponds to the first and second rack respectively. The number (10) corresponds to the reciprocating member;(9) corresponds to the rollers on both side of the reciprocating member.(ll) shows the slot provided for the free movement of the reciprocating member

DETAILED DESCRIPTION OF DRAWINGS

Accordingly, the present invention provides an innovative reciprocating mechanism which uses roc/f and segmented gear mechanism. Unlike the traditional rack and pinion mechanism which converts rotary motion into linear motion the present invention converts rotary motion into reciprocating motion. The present invention comprises of a reciprocating member (10) which supports the racl