FORM 2
THE PATENT ACT, 1970
(39 of 1970)
&
THE PATENTES RULES, 2005
COMPLETE SPECIFICATION (See section 10, rule 13)
1. TITLE OF THE INVENTION
"Crank-Less Engine for Automotive Applications"
2. APPLICANT(S)
(a) Name : MAHINDRA & MAH1NDRA LIMITED
(b) Nationality : Indian Company registered under the provisions
of the Companies Act, 1956
(c) Address : R&D Center, Automotive Sector,
89, M.I.D.C, Satpur, NASHIK-422 007 Maharashtra State, India
3. PREAMBLE OF THE DESCRIPTION
COMPLETE
The following specification particularly describes the invention and the manner in which it is to be performed.

Crank-Less Engine for Automotive Applications
Field of the invention
The present invention is related to an internal combustion engine, more particularly the present invention relate an internal combustion engine with a rack and gear mechanism converting reciprocating motion of a piston to a rotary motion of a shaft of the engine.
Background of the invention
Conventional and commercially available internal combustion (1C) engines in the art uses a crank shaft to transform the reciprocating motion of a piston into rotary motion of the output shaft wherein the piston is connected to a crankshaft through a connecting rod. The up and down movement of the piston in the cylinder bore in response to the expanding gases of the combustion imparts a rotary motion to the crank shaft through the connecting rod. One end of the connecting rod is pivotally connected to the piston through a piston pin and other end of the connecting rod is rotatably joumaled to the crank shaft through a crank pin. The conventional system has the disadvantage that during the power stroke actual power generated inside the combustion chamber is not proportionally converted to torque on the crankshaft's main journal due to the dynamic losses in the piston to connecting rod to crankshaft linkage. Varying degree of attempts with no effective results has been made in the art to come up with the engine without crankshaft to over the drawback in the conventional system.
Crankless IC engines converting the reciprocating movement of the piston into rotary motion of the output shaft are disclosed by US patent numbers 3901093 and 4497284. These disclosures use a swash plate in place of the crank shaft to convert reciprocating motion of the piston into rotary motion of the shaft. In

this the output shaft is driven by means of a connecting rod which have simple clevis type attachment at both ends. Another US patent number 2274097 eliminates the conventional crank shaft from the engine wherein a piston imparts rotation to the cam plate through a wrist pin runners attached to a piston rod which reciprocates in guide grooves. Another prior art document US patent number 4498430 educates on the improvement over the arrangement and couplings between the piston and output power shaft of an internal combustion engine. The arrangement comprises of a connecting rod having a set of gear teeth along its side forming a rack gear. The sector gear of the arrangement engages the gear teeth on the rod only during one direction of the rod's reciprocating movement which is the same direction as the power stroke. The sector gear is disengaged from the rod at the end of the piston's power stroke and remains disengaged, while continuing to rotate, until the beginning of the next stroke with the same direction as the power stroke.
Accordingly a need to address these drawbacks of the conventional \C engines and prior art crankless engines is felt. An 1C engine is needed that proportionally converts the generated power from the combustion chamber to torque minimizing the parasitic losses.
Objectives of the invention
The main object of the present invention is to provide a crankless, compact and light weight internal combustion engine.
Another object of the present invention with a rack and gear mechanism is to convert the reciprocating motion of a piston to the rotary motion of a drive shaft.
Still another objective of the present invention is to reduce the parasitic losses of the piston with a connecting rod.

Still further object of the present invention is to produce more power than a conventional engine running with the same fuel, bore and compression ratio.
Further objective of the present invention is to provide more torque and runs smoother.
Summary of the invention
Accordingly, the present invention provides an internal combustion engine including
a piston having a front end enclosed in a cylinder and a piston pin positioned at a rear end thereof;
a rack having a bilateral teeth profile, the rack having a proximal end and a distal end, the proximal end journaled on the piston pin;
a first partially toothed gear and a second partially toothed gear, the first partially toothed gear engaging with a first half of the rack toothed profile and the second partially toothed gear engaging with a second half of the rack toothed profile to convert a power obtained from a reciprocating motion of the piston into a clockwise and an • anticlockwise motion;
a cam having a profile accommodating a follower on the distal end of the rack to accelerate and decelerate the reciprocating motion the piston;
a set of three gears converting the clockwise and anticlockwise motions of the first toothed gear and the second toothed gear to continuous rotary motion in synchronization with the cam; and
a drive shaft converting the power obtained from the toothed gear to an output.
Brief description of the figures:

The objects and advantages of the present invention will become apparent when the disclosure is read in conjunction with the following figures, wherein
Figure 1 shows a perspective view of a partially opened IC engine assembly with a rack and gear mechanism of the present invention;
Figure 2 shows an exploded perspective view of the rack and gear mechanism in accordance with the present invention;
Figure 3 shows a cross sectional view of the rack and gear mechanism with a cam of the present invention.
Figure 4 shows an acceleration and deceleration diagram of the piston with the cam in accordance with the present invention;
Figure 5 shows a front view of the cam with a profile with a follower in accordance with the present invention.
Figure 6 shows an exploded perspective view of a rack and gear mechanism in an alternate embodiment of the present invention;
Figure 7 shows a perspective view of a rack and gear mechanism of an alternate embodiment of the present invention as shown in Figure 6; and
Figure 8 shows a deceleration and an acceleration diagram of the piston in accordance with the alternate embodiment of the present invention as shown in Figure 6.
Figure 9 shows a perspective view of a rack and gear mechanism in an another alternate embodiment having a roller follower and a lever of the present invention;

Figure 10 shows a exploded perspective view of a rack and gear mechanism in an another alternate embodiment of the present invention as shown in Figure 9;
Figure 11 shows a perspective view of a rack and gear mechanism in a yet another alternate embodiment having a roller follower, a lever and a combination of gears of the present invention;
Figure 12 shows a exploded perspective view of a rack and gear mechanism in an another alternate embodiment of the present invention as shown in Figure 11;
Detailed description of the present invention:
The foregoing objects of the present invention are accomplished and the problems and shortcomings associated with the prior art, techniques and approaches are overcome by the present invention as described below in the preferred embodiments.
Accordingly the present invention discloses an internal combustion engine having a rack and gear mechanism to convert the reciprocating motion of a piston in to the rotary motion of a drive shaft reducing the parasitic losses of the piston with a connecting rod. The present invention produces more power than a conventional engine running with the same fuel, bore and compression ratio.
Referring to figures 1, 2 and 3. there is shown an internal combustion engine (100) (hereinafter termed as 'IC engine (100)') in accordance with the present invention. The IC engine (100) includes a cylinder (11), a piston (12), a toothed rack (hereinafter termed as 'rack' (13), a pair of partially toothed gears (hereinafter termed as 'toothed gears') (14), a cam (15), a set of three gears (16) and a drive shaft (17) (hereinafter termed as 'shaft' (17)).

The cylinder (11) in accordance with the present invention encloses a front end of the piston (12). The piston (12) has a piston pin (12a) positioned at a rear end allowing to be journaled with the rack (13).
The rack (13) having a proximal end (13a) and a distal end (13b). The proximal end (13a) of the rack (13) is journaled with the piston pin (12a). The distal end (13b) of the rack (13) engages with the cam (15). The rack (13) has a bilateral teeth profile has a first half (13c) and a second half (13d) to allow engaging with the partially toothed gears (14). Number of the teeth present on the rack (13) varies with the length of the rack travelling along with the piston pin (12a). Number of the teeth present circumferentially on the partially toothed gears (14) varies with the degrees of a circumferential and axial travel of the toothed gears (14) along with the rack (13).
The toothed gears (14) include a first partially toothed gear (14a) (hereinafter termed as 'first gear (14a)') and a second partially toothed gear (14b) (hereinafter termed as 'second gear (Mb)') intermittently obtain power from the reciprocating motion of the piston (12) and the rack (13). The toothed gears
(14) in assistance with the cam (15) convert / transform the power from the
reciprocating motion into the continuous rotary motion for the shaft (17).
The cam (15) is driven by an at least two links (18) that works in synchronization with the set of three gears (16). The cam (15) in synchronization with set of three gears (16) converts the reciprocating motion of the piston (12) and the rack (13) to a rotary motion of the shaft (17). The cam
(15) helps to slowly accelerate and decelerate the piston (12) at the beginning
and end of all the four strokes helping the engine to run without sudden stops
and avoiding breakage of engine components.
The cam (15) has a profile (15a) that adaptably accommodates a follower (20) on the rack (13). Peripheral length of the profile (15a) is directly proportional to

engine stroke. Contour of the profile (15a) is designed to meet velocity requirements as defined in the velocity diagram shown in figure 4. It is however understood that the dimensions of the profile (15a) are calculated to match the stroke and the piston velocity requirements of the IC engine (100). The dimensions of the profile (15a) vary with different applications of the 1C engine (100).
The follower (20) in the preferred embodiment is a pin / rod of predefined length engaging with the rack (13) either of the toothed profile assisting the acceleration and deceleration of the piston (12). The shaft (17) rotating in a rotatory motion converts the power obtained from the toothed gear (14) to an output for further application.
In an expansion stroke cycle, the first partially toothed gear (14a) engages with the first half (13c) of the rack (13) toothed profile. The first gear (14a) rotates in an anti-clockwise manner receiving the power in an intake stroke. In a compression stroke cycle, the second partially toothed gear (14b) engages with the second half (13d) of the rack (13) toothed profile. The second gear rotates in a clockwise manner compressing the piston (12) with an exhaust stroke. The combination set of three gears (16) adaptably converts the clockwise and the anticlockwise motions of the first gear (14a) and the second toothed gear (14b) channeling the power to the shaft (17). The cam profile (15a) adaptably decelerates the rack (13) resulting deceleration of the piston (12) at a top dead center (hereinafter termed as 'TDC') end and a bottom dead center (hereinafter termed as 'BDC') end in the start of each stroke. The cam (15) stops the rack (13) at a final position of the piston (12) and accelerates movement of the piston
(12) and the rack (13) in the opposite direction in the end of each stroke.
Referring to figures 4 and 5, illustrates an operational cycle of the IC engine. In a power expansion stroke cycle of the IC engine (100): the piston (12), the rack
(13) and the follower (20) initially moves down from the TDC end with constant

acceleration. The follower (20) slides through the profile (15a) of the cam (15) allowing rotation of the shaft (17). The follower (20) disengages from the cam (15) after completing 45 degrees of an initial rotation of the shaft (17). The first gear (14a) engages with the rack (13) rotating the shaft (17) by 90 degrees with constant velocity. The rotated position of the shaft (17) at 135 degrees facilitates the first gear (14a) to disengage from the rack (13) and allows the follower (20) to engage with the profile (15a) of the cam (15). The engagement of the follower (20) allows deceleration of the rack (13) and stopping the rack (13) at the BDC end, positioning the shaft (17) at 180 degrees.
In the compression stroke cycle, the profile (15a) of the cam (15) allows the follower (20) and the rack (13) to travel from the BDC end to move in an upwards direction at a uniform acceleration rotating the shaft (17) onto 225 degrees. The follower (20) disengages from the cam (15) at 225 degrees. The second gear (14b) engages with the rack (13) and lifts the rack (13) an upwards direction at constant velocity. The rotated position of the shaft (17) at 315 degrees facilitates the second gear (14b) to disengage from the rack (13) and allows the follower (20) to engage with the profile (15a) of the cam (15). The engagement of the follower (20) allows deceleration the rack (13) and stopping the rack (13) at the TDC end, positioning the shaft (17) at 360 degrees. The sequential expansion and compression cyclic process enables continuous shaft (17) rotation.
Referring to figures 6, 7 and 8 illustrates an alternate embodiment of the present invention having an internal combustion engine (200) (hereinafter termed as MC engine') of the present invention, includes a cylinder (151), a piston (152), a toothed rack (153) (hereinafter termed as 'rack (153)'), a pair of partially toothed gears (154) (hereinafter termed as 'toothed gears (154)'), a profiled cam (155) (hereinafter termed as 'cam (155)'), a set of three gears (Not shown) and a drive shaft (156) (hereinafter termed as 'shaft (156)'). The cylinder (151) encloses a front end of the piston (152). The rack (153) at proximal end is

journaled on a piston pin (152a) connecting the piston (152) at a rear end. A distal end of the rack (153) engages with the cam (155). The rack (153) has bilateral teeth profile to allow engaging with the partially toothed gears (154). Number of the teeth present on the rack (153) varies with the length of the rack travelling along with the piston pin (152a). Number of the teeth present circumferentially on the partially toothed gears (154) varies with the degrees of a circumferential and axial travel of the toothed gears (154) along with the rack (153).
The cam (155) has a profile (155a) that adaptably accommodates a projection (not shown in figure) on the gear (154). The cam (155) driven by an at least two links (158) works in synchronization with a set of three gears (Not shown). The cam (155) in synchronization with the set of three gears converts a reciprocating motion of the piston (152) and the rack (153) to a rotary motion of the shaft (156). The two strategically toothed gears (154) intermittently obtain power from the reciprocating motion of the piston (152) and the rack (153). The toothed gears (154) in assistance with the cam (155) convert / transform the power from the reciprocating motion into the continuous rotary motion for the . shaft (156).
In an expansion stroke cycle, a first partially toothed gear (154a) (hereinafter termed as 'first gear (154a)') engages with a first half of the rack (153) toothed profile. The first gear (154a) rotates in an anti-clockwise manner receiving the power in an intake stroke. In a compression stroke cycle, a second partially toothed gear (154b) (hereinafter termed as 'second gear (154b)') engages with a second half of the rack (153) toothed profile. The second gear (154b) rotates in a clockwise manner compressing the piston (152) with an exhaust stroke. The combination set of three gears (16) adaptably converts the clockwise and the anticlockwise motions of the first gear (154a) and the second gear (154b) channeling the power to shaft (156). The cam (155) profile adaptably decelerates the rack (153) resulting deceleration of the piston (152) at a top dead

center (hereinafter termed as TDC) end and a bottom dead center (hereinafter termed as 'BDC') end in the start of each stroke. The cam (155) stops the rack (153) at a final position of the piston (152) and accelerates movement of the piston (152) and the rack (153) in the opposite direction in the end of each stroke.
Referring to figures 9 and 10 illustrates an another alternate embodiment of the present invention having an alternate cam and follower arrangement. The operational cycle of the 1C engine with the alternate cam arrangement is described as follows.
During a power expansion stroke cycle of the IC engine, the piston, a rack (113) and a roller follower (120) initially moves down from the TDC end with constant acceleration from 0 to 45 degrees. The roller follower (120) is engaged in a profiled cam (115) (hereinafter termed as 'cam (115)'). The cam (115) has a profile (119) that adaptably accommodates the roller follower (120) on the rack (113). The cam (115) pushes the roller follower (120) down to rotate a lever (121) in a clockwise direction. At 45 degrees of the power stroke, the roller follower (120) disengages from the profile (119). At this time a first gear (114a) engages with the rack (113) rotating the first gear (114) in the clockwise direction. The rotated position at 135 degrees facilitates the first gear (114) to disengage from the rack (113) and allows the follower (120) to engage with the profile (! 19) of the cam (115). From 135 degrees of power stroke, the roller follower (120) cycles the rack (113) to BDC (180 to 225 degrees) in a compression stroke. At 225 degrees of the compression stroke, the roller follower (120) disengages from the profile (119). A second gear engages on rack (113) and helps the system to continue its compression stroke. At 315 degrees of compression stroke, the second gear disengages from the rack (113) and the roller follower (120) engages in the cam (115) profile (119). The roller follower (120) cycles the cam (115) and the rack (113) from 315 degrees to TDC / 360 / 0 degrees. The sequential expansion and compression cyclic process enables continuous rotation.

Referring to figures 11 and 12 illustrates a yet another alternate embodiment of the present invention having an alternate cam and follower arrangement. The operational cycle of the IC engine with the alternate cam arrangement is described as follows.
During a power expansion stroke cycle of the IC engine, the piston, a rack (213) and a roller follower (220) initially moves down from the TDC end with constant acceleration from 0 to 45 degrees. The roller follower (220) is engaged in a profiled cam (215) (hereinafter termed as 'cam (215)?). The cam (215) has a profile (219) that adaptably accommodates the roller follower (220) on the rack (213). The cam (215) pushes the roller follower (220) down to rotate a lever (221) in accordance with a combination of gears (222). The lever (221) rotates in an anticlockwise direction. At 45 degrees of the power stroke, the roller follower (220) disengages from the profile (219). At this time a first gear (214a) engages with the rack (213) rotating the first gear (214a) in the anti-clockwise direction. The rotated position at 135 degrees facilitates the first gear (214a) to disengage from the rack (213) and allows the follower (220) to engage with the profile (219) of the cam (215). From 135 degrees of power stroke, the roller follower (220) cycles the rack (213) to BDC (180 to 225 degrees) in a compression stroke. At 225 degrees of the compression stroke, the roller follower (220) disengages from the profile (219). A second gear (214b) engages on rack (213) and helps the system to continue its compression stroke. At 315 degrees of compression stroke, the second gear (214b) disengages from the rack (213) and the roller follower (220) engages in the cam (215) profile (219). The roller follower (220) cycles the cam (215) and the rack (213) from 315 degrees to TDC / 360 / 0 degrees. The sequential expansion and compression cyclic process enables continuous rotation. The combination of gears (222) and gear with lever (221) helps the power take off shaft in one direction.

In various aspect of the present invention with certain variations and rearrangements different output or applications are obtained using preferred modification.
- In an aspect of the present invention increasing the piston / bore
diameter and stroke length increases the liter size/capacity of the
engine.
In an another aspect of the present invention increasing the piston number of the IC engine with minor structural modification allows to be used a Multi cylinder inline 'I - Engine' and/or 'V - Engine'
- In a yet another aspect of the present invention. IC engine with a pistons positioned on each end of the rack is used as a flat opposed cylinder engine.
- In an another aspect, the rack and gear of the present IC engine in conjunction with permanent magnet and coil is used as electricity generator.
- In a yet another aspect of the present invention, the rack and gear of the present IC engine in conjunction with hydraulic / pneumatic reciprocating pumps is used to generate hydraulic / pneumatic power.
- In one more aspect of the present invention, minor modification in timing and a valve of the present IC engine enables to be used as a pneumatic and/or steam engine.
Advantages
The technical advantages achieved by the present invention are,
- The present invention produces more power than a conventional engine running with the same fuel bore and compression ratio.
- The present invention reduces the parasitic losses occurring in a conventional engine's having piston-crankshaft mechanism,

- An absence of oscillating parts allows the IC engine (100) to run very smoothly.
- A constant torque is produced that is greater than the conventional engines in the art.
- The IC engine (100) running with the constant torque in absence of oscillating parts allows the IC engine (100) to idled at lower RPMs.
- The IC engine (100) is 25% fuel efficient producing 25% more torque than the conventional engines in the art.
- Rack and gear with the help of cam helps the piston to move faster than an identical conventional engine that reduces engine knock.
Burnt gasses are released faster than an identical conventional engine and runs at lower temperature.
The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omission and substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but such are intended- to cover the application or implementation without departing from the spirit or scope of the present invention.

We Claim
1. An internal combustion engine comprising:
a piston having a front end enclosed in a cylinder and a piston pin positioned at a rear end thereof;
a rack having a bilateral teeth profile, the rack having a proximal end and a distal end, the proximal end journaled on the piston pin;
a first partially toothed gear and a second partially toothed gear, the first partially toothed gear engaging with a first half of the rack toothed profile and the second partially toothed gear engaging with a second half of the rack toothed profile to convert a power obtained from a reciprocating motion of the piston into a clockwise and an anticlockwise motion;
a cam having a profile accommodating a follower on the distal end of the rack to accelerate and decelerate the reciprocating motion the piston;
a set of three gears converting the clockwise and anticlockwise motions of the first toothed gear and the second toothed gear to continuous rotary motion in synchronization with the cam; and
a drive shaft converting the power obtained from the toothed gear to an output.
2. The internal combustion engine as claimed in claim I, wherein the cam is driven by an at least two links working in synchronization with the set of three gears.
3. The internal combustion engine as claimed in claim 1, wherein the first partially toothed gear and the second partially toothed gear convert a power obtained from a reciprocating motion of the piston into continuous rotary motion of the drive shaft.

4. The internal combustion engine as claimed in claim 1, wherein the follower is fixedly attached with the toothed profile of the rack.