Internal combustion engine

A balanced five cycle internal combustion engine having first and second inlet and outlet annular cams configured to move first and second inlet and outlet pistons respectively within associated cylinders through successive five cycle repeating movements each of which includes (1) a power cycle, (2) an exhaust cycle, (3) a transfer cycle, (4) an intake cycle, and (5) a compression cycle. The movements of each first inlet piston and an associated first inlet cam follower being accompanied by an equal and opposite movement of a second inlet piston and an associated second inlet cam follower so that all movements of the first and second inlet pistons and the associated first and second inlet cam followers thereof are dynamically balanced. The movements of each first outlet piston and an associated first outlet cam follower being accompanied by an equal and opposite movement of a second outlet piston and an associated second outlet cam follower so that all movements of the first and second outlet pistons and the associated first and second outlet cam followers thereof are dynamically balanced.

This invention relates to internal combustion engines and more particularly
 to improvements in five cycle engines embodying annularly arranged
 cylinders having opposed pistons movable by annular cam tracks.
 BACKGROUND OF THE INVENTION
 Five cycle engines of the type herein contemplated have been proposed in
 the patented literature for more than sixty-eight years. The Packard Motor
 Car Co. was granted U.S. Pat. No. 1,788,140, on Jan. 6, 1931, which
 discloses the basic five cycle engine herein contemplated.
 The '140 patent discloses an internal combustion engine comprising a
 housing, a plurality of annularly arranged cylinders in the housing
 disposed with their axes parallel with a central longitudinal rotor axis.
 Each of the cylinders includes an inlet end portion having an inlet port
 therein, a central working portion, and an outlet end portion having an
 outlet port therein. An inlet piston is mounted in each cylinder
 constructed and arranged to be moved in sealing relation to the associated
 cylinder from an inlet end position wherein the inlet port thereof
 communicates with the working portion thereof in an axial direction away
 from the inlet end position into an inlet port cut-off position wherein
 the inlet piston cuts off communication of the inlet port thereof with the
 working portion thereof and beyond into the working portion thereof. An
 outlet piston is mounted in each cylinder constructed and arranged to be
 moved in sealing relation to the associated cylinder from an outlet end
 position thereof wherein the outlet port thereof is communicated with the
 working portion thereof in an axial direction away from the outlet end
 position into an outlet port cut-off position wherein the outlet piston
 cuts off the communication of the outlet port thereof with the working
 portion thereof and beyond into the working portion thereof. Rotor
 structure within the housing is constructed and arranged to move with a
 rotational movement within the housing about the central rotor axis. Each
 of the inlet pistons includes an inlet cam follower constructed and
 arranged to follow an annular inlet cam during the rotation of the rotor
 structure. Each of the outlet pistons includes an outlet cam follower
 constructed and arranged to follow an annular outlet cam during the
 rotation of the rotor structure. The inlet and outlet annular cams are
 configured to move the inlet and outlet pistons within each cylinder
 through a successive five-cycle repeating movement which includes (1) a
 power cycle wherein the inlet and outlet pistons are moved axially
 outwardly from combustion positions disposed in closely spaced relation
 within the working portion of the associated cylinder into the respective
 cut-off positions thereof, (2) an exhaust cycle wherein the outlet piston
 is moved from the outlet cut-off position thereof into the outlet end
 position thereof and the inlet piston is moved through the working portion
 thereof into close proximity to the outlet piston, (3) a transfer cycle
 wherein the inlet and outlet pistons are moved together in close proximity
 to each other through the working portion thereof, (4) an intake cycle
 wherein the outlet piston is initially moved through the working portion
 of the associated cylinder while the inlet piston is in a position
 allowing communication of the inlet port with the working portion with the
 final movement of the intake cycle resulting in the inlet and outlet
 pistons being in compression positions spaced from the respective end
 positions thereof so that the communication of the respective ports are
 cut off from the working portion of the associated cylinder, and (5) a
 compression cycle wherein the inlet and outlet pistons are moved from the
 compression positions thereof toward each other into the combustion
 positions.
 The '140 patent disclosure contemplates that the compression positions of
 the inlet and outlet pistons in the intake cycle constitute the respective
 cut-off positions thereof, both of which are moved directly therein during
 the final movements of the intake cycle. In this way, a maximum power is
 achieved and opposed piston movement balance is achieved during the full
 movement of the opposed pistons during compression as well as during
 expansion.
 It is noted, however, that the transfer cycle introduces an imbalance
 because both pistons are moved together through a full stroke. Similarly,
 the intake and exhaust cycles involve different movements of the pistons
 in the same direction.
 Over the years, there have been various improvements on the basic
 five-cycle engine proposed in the patented literature. The Packard Motor
 Car Co. was granted improvement U.S. Pat. No. 1,808,083, contemporaneously
 with the basic '140 patent on Jun. 2, 1931. This Packard improvement was
 directed toward diminishing the imbalanced movement of the pistons
 together during the transfer cycle by essentially halving the movement
 required and doubling the five cycle operation to a ten cycle operation.
 U.S. Pat. No. 5,289,802 introduced two features of improvement in the basic
 five-cycle operation. First, an increased compression-expansion ratio
 beyond one is proposed where the compression positions of the inlet and
 outlet pistons in the intake cycle constitute the cut-off position of the
 inlet piston and an intermediate position of the outlet piston disposed
 inwardly of the outlet cut-off position thereof, both of which are moved
 directly therein during the final movements of the intake cycle. The
 intake cycle is essentially accomplished by a movement of the outlet
 piston within the cylinder which positively displaces a new charge through
 the open inlet port. Second, the inlet and outlet annular cams retain the
 inlet and outlet pistons substantially in combustion positions longer than
 simple harmonic motion for a time sufficient to enable a new fueled gas
 charge within the minimum column to be ignited and to rise to maximum
 pressure before substantial volume increase toward the maximum volume
 during the power cycle takes place to thereby eliminate negative work
 resulting from ignition prior to reaching the minimum volume condition and
 to obtain optimal work from optimal pressure conditions.
 While these improvements to some extent have a positive effect on the
 inherent imbalance of the basic five-cycle movement, it is apparent that
 the problem of inherent imbalance has gone unsolved since 1931 despite the
 various improvements which have been proposed over the years.
 BRIEF DESCRIPTION OF THE PRESENT INVENTION
 It is an object of the present invention to solve the imbalance problems
 inherent in the basic five cycle engine as disclosed in the '140 patent.
 While some of the five-cycle engine improvements of the prior art deal
 importantly with the imbalance problems presented, none have completely
 solved the problems presented. This objective is achieved in accordance
 with the principles of the present invention by the provision of balanced
 five-cycle internal combustion engine comprising a housing assembly having
 a longitudinal axis and a central plane perpendicular to the longitudinal
 axis. A plurality of first cylinders is provided in the housing assembly
 on one side of the central plane having parallel axes disposed in
 annularly spaced relation about the longitudinal axis. A plurality of
 second cylinders is provided in the housing assembly on an opposite side
 of the central plane and disposed in coaxial mirror image relation with
 respect to the plurality of first cylinders respectively. Each of the
 plurality of first and second cylinders includes an inlet end portion
 having an inlet port therein, a central working portion and an outlet end
 portion having an outlet port therein. The inlet end portion, the central
 working portion and the outlet end portion of said plurality of first
 cylinders are arranged in mirror image relation with respect to the inlet
 end portion, the central working portion and the outlet end portion of the
 plurality of second cylinders respectively. A first inlet piston is
 mounted in an associated first cylinder constructed and arranged to be
 moved in sealing relation to the associated first cylinder from an inlet
 end position wherein the inlet port thereof communicates with the working
 portion thereof in an axial direction away from the inlet end position
 into an inlet port cut-off position wherein the inlet piston cuts off
 communication of the inlet port thereof with the working portion thereof
 and beyond into the working portion thereof. A second inlet piston is
 mounted in an associated second cylinder constructed and arranged to be
 moved in sealing relation to the associated second cylinder from an inlet
 end position wherein the inlet port thereof communicates with the working
 portion thereof in an axial direction away from the inlet end position
 into an inlet port cut-off position wherein the inlet piston cuts off
 communication of the inlet port thereof with the working portion thereof
 and beyond into the working portion thereof. Each first inlet piston has a
 mass generally equal to the mass of a second inlet piston disposed in
 mirror image relation thereof, so as to be statically balanced therewith.
 A first outlet piston is mounted in an associated first cylinder of each
 of the first plurality of cylinders constructed and arranged to be moved
 in sealing relation to the associated cylinder from an outlet end position
 wherein the outlet port thereof is communicated with the working portion
 thereof in an axial direction away from the outlet end position into an
 outlet port cut-off position wherein the outlet piston cuts off the
 communication of the outlet port thereof with the working portion thereof
 and beyond into the working portion thereof. A second outlet piston is
 mounted in an associated second cylinder of each of the second plurality
 of cylinders constructed and arranged to be moved in sealing relation to
 the associated second cylinder from an outlet end position wherein the
 outlet port thereof is communicated with the working portion thereof in an
 axial direction away from the outlet end position into an outlet port
 cut-off position wherein the outlet piston cuts off the communication of
 the outlet port thereof with the working portion thereof and beyond into
 the working portion thereof. Each first outlet piston has a mass generally
 equal to the mass of a second outlet piston disposed in mirror image
 relation thereto so as to be statically balanced therewith. Rotor
 structure within the housing assembly is constructed and arranged to move
 with a rotational movement about the longitudinal axis. A first annular
 inlet cam is disposed annularly about the longitudinal axis on one side of
 the central plane. A first inlet cam follower is operatively connected
 between the first annular inlet cam and each of the first inlet pistons so
 as to effect axial movements thereof in opposite directions during the
 rotation of the rotor structure about the longitudinal axis. A second
 annular inlet cam is disposed annularly about the longitudinal axis on the
 opposite side of the central plane. A second inlet cam follower is
 operatively connected between the second annular inlet cam and each of the
 second inlet pistons so as to effect axial movements thereof in opposite
 directions during the rotation of the rotor structure about the
 longitudinal axis. Each first inlet cam follower has a mass generally
 equal to the mass of an associated second inlet cam follower disposed in
 mirror image relation thereto so as to be statically balanced therewith. A
 first annular outlet cam is disposed annularly about the longitudinal axis
 on the opposite side of the central plane. A first outlet cam follower is
 operatively connected between the first annular outlet cam and each of the
 first outlet pistons so as to effect axial movements thereof in opposite
 directions during the rotation of the rotor structure about the
 longitudinal axis. A second annular outlet cam is disposed annularly about
 the longitudinal axis on the opposite side of the central plane. A second
 outlet cam follower is operatively connected between the first annular
 outlet cam and each of the first outlet pistons so as to effect axial
 movements thereof in opposite directions during the rotation of the rotor
 structure about the longitudinal axis. Each first outlet cam follower has
 a mass generally equal to the mass of an associated second outlet cam
 follower disposed in mirror image relation thereto so as to be statically
 balanced therewith. The first and second inlet and outlet annular cams are
 configured to move the first and second inlet and outlet pistons
 respectively within each cylinder through a successive five cycle
 repeating movement which includes (1) a power cycle wherein the first and
 second inlet and outlet pistons are moved axially outwardly from
 combustion positions disposed in closely spaced relation within the
 working portion of the associated cylinder defining a minimum volume
 condition into a respective cut-off positions thereof defining a maximum
 volume condition, (2) an exhaust cycle wherein the first and second outlet
 pistons are moved from the outlet cut-off position thereof into the outlet
 end position thereof and the first and second inlet pistons are moved
 through the working portion thereof into close proximity to the first and
 second outlet pistons respectively, (3) a transfer cycle wherein the first
 and second inlet and outlet pistons are moved together in close proximity
 to each other through the working portion thereof, (4) an intake cycle
 wherein the first and second outlet pistons are initially moved through
 the working portion of the associated cylinder while the first and second
 inlet pistons respectively are in a position allowing communication of the
 first and second inlet ports respectively with the associated working
 portions with the final movement of the intake cycle resulting in the
 first and second inlet and outlet pistons being in compression positions
 spaced from the respective end positions thereof so that the communication
 of the respective ports are cut off from the working portion of the
 associated cylinder, and (5) a compression cycle wherein the first and
 second inlet and outlet pistons are moved from the compression positions
 thereof toward each other respectively into the combustion positions.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION
 Referring now more particularly to FIG. 1 of the drawings, there is shown
 therein a balanced five-cycle combustion engine, generally indicated at
 10, embodying the principles of the present invention.
 The engine 10 includes a housing assembly, generally indicated at 12,
 having a longitudinal axis and a central plane perpendicular thereto.
 Within the housing assembly 12, on one side of the central plane is a
 plurality of annularly arranged first cylinders, generally indicated at
 14, having axes which are disposed in an annularly spaced parallel
 relation with respect to the longitudinal axis. Disposed in the housing
 assembly 12 on the opposite side of the central plane is a plurality of
 second cylinders 14' which are arranged in coaxial mirror image relation
 with respect to the plurality of first cylinders 14 respectively.
 Each of the plurality of first cylinders 14 has an inlet end portion 16
 having one or more inlet ports 18 therein, a central working portion 20,
 and an outlet end portion 22 having one or more outlet ports 24 therein.
 Each of the plurality of second cylinders 14' has an inlet end portion 16'
 having one or more inlet ports 18' therein, a central working portion 20',
 and an outlet end portion 22.degree. having one or more outlet ports 24'
 therein. The inlet end portion 16, the central working portion 20, and the
 outlet end portion 22 of said plurality of first cylinders 14 are arranged
 in mirror image relation with respect to the inlet end portion 16', the
 central working portion 20', and the outlet end portion 22' of the
 plurality of second cylinders 14' respectively.
 A first inlet piston 26 is mounted in an associated first cylinder 14 of
 each of the plurality of first cylinders 14. Each first inlet piston 26 is
 constructed and arranged to be moved in sealing relation to the associated
 first cylinder 14 from an inlet end position wherein the inlet ports 18
 thereof communicates with the working portion 20 thereof. Each first inlet
 piston 26 moves in an axial direction away from the inlet end position
 into an inlet port cut-off position wherein the first inlet piston 26 cuts
 off communication of the inlet port 18 of the associated first cylinder 14
 with the working portion 20 thereof and beyond into the working portion 20
 thereof.
 A second inlet piston 26' is mounted in an associated second cylinder 14'
 of each of the plurality of second cylinders 14'. Each second inlet piston
 26' is constructed and arranged to be moved in sealing relation to the
 associated second cylinder 14' from an inlet end position wherein the
 inlet ports 18' thereof communicates with the working portion 20' thereof.
 Each second inlet piston 26' moves in an axial direction away from the
 inlet end position into an inlet port cut-off position wherein the second
 inlet piston 26' cuts off communication of the inlet port 18' of the
 associated second cylinder 14' with the working portion 20' thereof and
 beyond into the working portion 20' thereof.
 Each first inlet piston 26 has a mass generally equal to the mass of an
 associated second inlet piston 26' arranged in mirror image relation
 thereto so as to be statically balanced therewith.
 A first outlet piston 28 is mounted in an associated first cylinder 14 of
 each of the first plurality of cylinders 14 and is constructed and
 arranged to be moved in sealing relation thereto from an outlet end
 position 20 wherein the outlet ports 24 thereof communicate with the
 working portion 20 thereof. Each first outlet piston 28 moves in an axial
 direction away from the outlet end position into an outlet port cut-off
 position wherein the outlet piston 28 cuts off the communication of the
 outlet ports of the associated first cylinder 14 with the working portion
 20 thereof and beyond into the working portion 20 thereof.
 A second outlet piston 28' is mounted in an associated second cylinder 14'
 of each of the second plurality of cylinders 14' and is constructed and
 arranged to be moved in sealing relation thereto from an outlet end
 position 20' wherein the outlet ports 24' thereof communicate with the
 working portion 20' thereof. Each second outlet piston 28' moves in an
 axial direction away from the outlet end position into an outlet port
 cut-off position wherein the outlet piston 28' cuts off the communication
 of the outlet ports of the associated second cylinder 14' with the working
 portion 20' thereof and beyond into the working portion 20' thereof.
 Each first outlet piston 28 has a mass generally equal to the mass of an
 associated second outlet piston 28' arranged in mirror image relation
 thereto so as to be statically balanced therewith.
 A rotor structure, generally indicated at 30, is mounted within the housing
 assembly 12 and is constructed and arranged for rotational movement
 therein about the longitudinal axis.
 Each of the first inlet pistons 26 includes a first inlet cam follower in
 the form of a pair of axially spaced rollers 32 constructed and arranged
 to follow a first annular inlet cam 34, disposed annularly about the
 longitudinal axis on one side of the central plane, during the rotation of
 rotor structure 30 so as to effect axial movements thereof in opposite
 directions.
 Each of the second inlet pistons 26' includes a second inlet cam follower
 in the form of a pair of axially spaced rollers 32' constructed and
 arranged to follow a second annular inlet cam 34', disposed annularly
 about the longitudinal axis on the opposite side of the central plane,
 during the rotation of rotor structure 30 so as to effect axial movements
 thereof in opposite directions.
 Each first inlet cam follower 32 has a mass generally equal to the mass of
 an associated second inlet cam follower 32' and is arranged in mirror
 image relation thereto so as to be statically balanced therewith.
 Each of the first outlet pistons 28 includes a first outlet cam follower in
 the form of a pair of axially spaced rollers 36 constructed and arranged
 to follow a first annular outlet cam 38, disposed annularly about the
 longitudinal axis on one side of the central plane, during the rotation of
 rotor structure 30 so as to effect axial movements thereof in opposite
 directions.
 Each of the second outlet pistons 28' includes a second outlet cam follower
 in the form of a pair of axially spaced rollers 36' constructed and
 arranged to follow a second annular outlet cam 38', disposed annularly
 about the longitudinal axis on the opposite side of the central plane,
 during the rotation of rotor structure 30 so as to effect axial movements
 thereof in opposite directions.
 Each first outlet cam follower 36 has a mass generally equal to the mass of
 an associated second outlet cam follower 36' and is arranged in mirror
 image relation thereto so as to be statically balanced therewith.
 The first inlet and outlet annular cams, 34 and 38, are configured to move
 the first inlet and outlet pistons, 26 and 28, within each first cylinder
 14 through a successive five-cycle repeating movement which includes
 (1) a power cycle wherein the first inlet and outlet pistons, 26 and 28,
 are moved axially outwardly from combustion positions disposed in closely
 spaced relation within the working portion 20 of the associated cylinder
 14 defining a minimum volume condition into the respective cut-off
 positions thereof defining a maximum volume condition;
 (2) an exhaust cycle wherein the first outlet piston 28 is moved from the
 outlet cut-off position thereof into the outlet end position thereof and
 the first inlet piston 26 is moved through the working portion 20 thereof
 into close proximity to the first outlet piston 28;
 (3) a transfer cycle wherein the first inlet and outlet pistons, 26 and 28,
 are moved together in close proximity to each other through the working
 portion 20 of the associated first cylinder 14;
 (4) an intake cycle wherein the first outlet piston 28 is initially moved
 through the working portion 20 of the associated first cylinder 14 and
 into the outlet end position and thereafter the first inlet piston 26 is
 moved beyond the inlet cut-off position within the associated first
 cylinder 14, and during the latter portion of this movement, the first
 outlet piston 28 is moved from the outlet end position thereof into the
 outlet cut-off position thereof resulting in the first inlet and outlet
 pistons, 26 and 28, being in compression positions spaced from the
 respective end positions thereof so that the communication of the
 respective ports, 18 and 24, are cut off from the working portion 20 of
 the associated first cylinder 14;
 and (5) a compression cycle wherein the first inlet and outlet pistons, 26
 and 28, are moved from the compression positions thereof toward each other
 into the combustion positions.
 The second inlet and outlet annular cams, 34' and 38', are configured to
 move the second inlet and outlet pistons, 26' and 28', within each second
 cylinder 14' through a successive five-cycle repeating movement which
 includes
 (1) a power cycle wherein the second inlet and outlet pistons, 26' and 28',
 are moved axially outwardly from combustion positions disposed in closely
 spaced relation within the working portion 20' of the associated cylinder
 14' defining a minimum volume condition into the respective cut-off
 positions thereof defining a maximum volume condition,
 (2) an exhaust cycle wherein the second outlet piston 28' is moved from the
 outlet cut-off position thereof into the outlet end position thereof and
 the second inlet piston 26' is moved through the working portion 20'
 thereof into close proximity to the second outlet piston 28';
 (3) a transfer cycle wherein the second inlet and outlet pistons, 26' and
 28', are moved together in close proximity to each other through the
 working portion 20' of the associated second cylinder 14';
 (4) an intake cycle wherein the second outlet piston 28' is initially moved
 through the working portion 20' of the associated second cylinder 14' and
 into the outlet end position and thereafter the second inlet piston 26' is
 moved beyond the inlet cut-off position within the associated second
 cylinder 14', and during the latter portion of this movement, the second
 outlet piston 28' is moved from the outlet end position thereof into the
 outlet cut-off position thereof resulting in the second inlet and outlet
 pistons, 26' and 28', being in compression positions spaced from the
 respective end positions thereof so that the communication of the
 respective ports, 18' and 24', are cut off from the working portion 20' of
 the associated second cylinder 14';
 (5) a compression cycle wherein the second inlet and outlet pistons, 26'
 and 28', are moved from the compression positions thereof toward each
 other into the combustion positions.
 The movements of each first inlet piston 26 and an associated first inlet
 cam follower 32 being accompanied by an equal and opposite movement of a
 second inlet piston 26' and an associated second inlet cam follower 32' so
 that all movements of the first and second inlet pistons, 26 and 26', and
 the associated first and second inlet cam followers, 32 and 32', thereof
 are dynamically balanced.
 The movements of each first outlet piston 28 and an associated first outlet
 cam follower 36 being accompanied by an equal and opposite movement of a
 second outlet piston 28' and an associated second outlet cam follower 36'
 so that all movements of the first and second outlet pistons, 28 and 28',
 and the associated first and second outlet cam followers, 36 and 36',
 thereof are dynamically balanced.
 While it is contemplated in the broadest aspects of the present invention
 that the first cylinders 14 could be rotated with the rotor structure 30
 and the first inlet and outlet annular cams, 34 and 38, fixed with respect
 to the housing assembly 12, it is preferable in accordance with the
 principles of the present invention to fix the first inlet and outlet
 annular cams 34 and 38 to the rotor structure 30 so that they rotate
 therewith and to fix the first cylinders 14 with respect to the housing
 assembly 12.
 While it is also contemplated in the broadest aspects of the present
 invention that the second cylinders 14' could be rotated with the rotor
 structure 30 and the second inlet and outlet annular cams, 34' and 38',
 fixed with respect to the housing assembly 12, it is preferable in
 accordance with the principles of the present invention to fix the second
 inlet and outlet annular cams 34' and 38' to the rotor structure 30 so
 that they rotate therewith and to fix the second cylinders 14' with
 respect to the housing assembly 12.
 It will be understood that the housing assembly 12 may assume different
 constructions. In the exemplary embodiment shown in the drawings, on one
 side of the central plane, the housing assembly 12 includes a pair of
 cup-shaped end housing members 40 which are disposed in spaced relation
 opening toward one another. The open end of each outer end housing member
 40 is fixed to a transverse housing wall or disk 42 which essentially
 covers the open end thereof. Between the two housing walls 42, a plurality
 of first cylinder housing members 44 are fixedly mounted with the ends
 thereof seated in annular grooves in the housing walls 42. Each first
 cylinder housing member 44 receives a first cylinder 14 therein with the
 central portion 20 thereof being engaged within the associated first
 cylinder housing member 44 and the marginal ends thereof seated within
 annular grooves in the housing walls 42. Each first cylinder housing
 member 44 has an enlarged bore forming a first inlet chamber 46 which
 communicates with the inlet ports 18 of the associated first cylinder 14.
 Each first cylinder housing member 44 also has an enlarged bore forming a
 first outlet chamber 48 which communicates with the outlet ports 24 of the
 associated first cylinder 14. In the embodiment shown, there are four
 first cylinders 14 and surrounding housing members 44 although it will be
 understood that less than four or more than four may be provided.
 In the exemplary embodiment shown in the drawings, on the other side of the
 central plane, the housing assembly 12 includes a pair of cup-shaped end
 housing members 40 which are disposed in spaced relation opening toward
 one another. The open end of each outer end housing member 40 is fixed to
 a transverse housing wall or disk 42' which essentially covers the open
 end thereof. Between the two housing walls 42', a plurality of second
 cylinder housing members 44' are fixedly mounted with the ends thereof
 seated in annular grooves in the housing walls 42'. Each second cylinder
 housing member 44' receives a second cylinder 14' therein with the central
 portion 20' thereof being engaged within the associated second cylinder
 housing member 44' and the marginal ends thereof seated within annular
 grooves in the housing walls 42'. Each second cylinder housing member 44'
 has an enlarged bore forming a second inlet chamber 46' which communicates
 with the inlet ports 18' of the associated second cylinder 14'. Each
 second cylinder housing member 44' also has an enlarged bore forming a
 second outlet chamber 48' which communicates with the outlet ports 24' of
 the associated second cylinder 14'. In the embodiment shown, there are
 four second cylinders 14' and surrounding housing members 44' although it
 will be understood that less than four or more than four may be provided.
 The first inlet and outlet chambers 46 and 48 could be intercommunicated
 between the housing walls 42 to form first inlet and outlet manifolds.
 However, as shown each first inlet chamber 46 has a radially extending
 first inlet tube 50 communicating therewith which leads to a suitable
 first inlet manifolding if desired (not shown). Similarly, each first
 outlet chamber 48 has a radially extending first outlet tube 52
 communicating therewith which also may lead to a suitable first outlet
 manifolding if desired (not shown).
 The second inlet and outlet chambers 46' and 48' could be intercommunicated
 between the housing walls 42' to form second inlet and outlet manifolds.
 However, as shown each second inlet chamber 46' has a radially extending
 second inlet tube 50' communicating therewith which leads to a suitable
 second inlet manifolding if desired (not shown). Similarly, each second
 outlet chamber 48' has a radially extending second outlet tube 52'
 communicating therewith which also may lead to a suitable second outlet
 manifolding if desired (not shown).
 Each first inlet and outlet pair of cam follower rollers 32 and 36 is
 rotatably carried by the associated first inlet and outlet pistons 26 and
 28 by a piston rod 54 fixed at one end thereto which extends in sliding
 guided relation through a sleeve 56 in the associated housing wall 42. The
 free end of each piston rod 54 is bifurcated to receive an associated
 first inlet roller 32 or outlet roller 36, which is mounted on a shaft 58
 extending through the bifurcation. Each piston rod 54 is also fixedly
 connected adjacent its bifurcated end to the central portion of a cross
 member 60. The ends of each cross member 60 are sleeved to slidably engage
 a pair of spaced axially extending cylindrical guide members 62. Each
 cross member 60 has a shaft 64 fixed thereto on which the other roller 32
 or 36 of the associated pair is journaled. In this way, each first inlet
 cam follower roller 32 and each first outlet cam follower roller 36 is
 guided for axial movement in opposite directions to follow the associated
 first annular inlet and outlet cam 34 and 38 during the rotation of the
 rotor structure 30.
 Each second inlet and outlet pair of cam follower rollers 32' and 36' is
 rotatably carried by the associated second inlet and outlet pistons 26'
 and 28' by a piston rod 54' fixed at one end thereto which extends in
 sliding guided relation through a sleeve 56' in the associated housing
 wall 42'. The free end of each piston rod 54' is bifurcated to receive an
 associated second inlet roller 32' or outlet roller 36', which is mounted
 on a shaft 58' extending through the bifurcation. Each piston rod 54' is
 also fixedly connected adjacent its bifurcated end to the central portion
 of a cross member 60'. The ends of each cross member 60' are sleeved to
 slidably engage a pair of spaced axially extending cylindrical guide
 members 62. Each cross member 60' has a shaft 64' fixed thereto on which
 the other roller 32' or 36' of the associated pair is journaled. In this
 way, each second inlet cam follower roller 32' and each second outlet cam
 follower roller 36' is guided for axial movement in opposite directions to
 follow the associated second annular inlet and outlet cam 34' and 38'
 during the rotation of the rotor structure 30.
 The first annular inlet cam 34 and first annular outlet cam 36 are each
 generally in the shape of an exteriorly flanged cup with an irregularly
 shaped peripheral wall. As previously indicated, the cams 34 and 38 are
 fixed to the rotor structure 50 to rotate therewith. The rotor structure
 50 includes a main shaft 66 suitably journaled in the end housing members
 40 and interior housing walls 42. Fixed to the main shaft 66 inwardly of
 the first inlet end thereof is a first inlet cam rotor disk member 68
 having a cylindrical inlet cam rotor wall 70 extending axially from the
 outer periphery thereof a variable distance throughout its annular extent.
 The first inlet cam 34 is specifically in the form of a radially outwardly
 extending flange on the free end of the cylindrical wall 70 which extends
 between each pair of first inlet cam follower rollers 32. Cam 34 has
 opposed cam surfaces 72 on which the roller 32 roll.
 The second annular inlet cam 34' and second annular outlet cam 36' are each
 generally in the shape of an exteriorly flanged cup with an irregularly
 shaped peripheral wall. As previously indicated, the cams 34' and 38' are
 fixed to the rotor structure 50' to rotate therewith. The rotor structure
 50' includes a main shaft 66' suitably journaled in the end housing
 members 40' and interior housing walls 42'. Fixed to the main shaft 66'
 inwardly of the second inlet end thereof is a second inlet cam rotor disk
 member 68' having a cylindrical inlet cam rotor wall 70' extending axially
 from the outer periphery thereof a variable distance throughout its
 annular extent. The second inlet cam 34' is specifically in the form of a
 radially outwardly extending flange on the free end of the cylindrical
 wall 70', which extends between each pair of second inlet cam follower
 rollers 32'. Cam 34' has opposed cam surfaces 72' on which the roller 32'
 roll.
 A similar outlet cam rotor disk member 74 is fixed to the main shaft 66
 inwardly of the first outlet end thereof. A similar first outlet cam rotor
 cylindrical wall 76 extends axially from the outer periphery of the disk
 member 74. The cylindrical wall 76 includes a radially outwardly extending
 flange which defines the first outlet cam 38 and has opposed cam surfaces
 78 on which each pair of first outlet cam follower rollers 36 roll.
 A similar outlet cam rotor disk member 74 is fixed to the main shaft 66'
 inwardly of the second outlet end thereof. A similar second outlet cam
 rotor cylindrical wall 76' extends axially from the outer periphery of the
 disk member 74. The cylindrical wall 76' includes a radially outwardly
 extending flange which defines the second outlet cam 38' and has opposed
 cam surfaces 78' on which each pair of second outlet cam follower rollers
 36' roll.
 FIG. 1 schematically illustrates first and second diesel fuel injectors, 80
 and 80', mounted to extend within and eject a charge of fuel into the
 central area of the associated working portion, 20 and 20', of the
 associated first and second cylinders, 14 and 14', respectively. Other
 conventional support equipment suitable for compression ignition
 combustion operation of the engine 10 are to be provided but are not
 shown. It will also be understood that the injectors 80 and 80' could be
 replaced by spark plugs (not shown) and the support equipment suitable for
 spark ignition combustion operation could be provided. In the description
 to follow, compression ignition combustion is the mode of operation but it
 will be understood that the description is equally applicable to spark
 ignition combustion taking into account the different compression ratio
 required.
 OPERATION OF THE EMBODIMENT OF FIGS. 1-12
 It will be understood that the cams 32 and 36, and the cams 32' and 36',
 are preferably shaped to provide two mirror-image five-cycle repetitive
 movements during each revolution of the cams 32 and 36, and 32' and 36',
 respectively with the rotor structure 30. However, it is within the
 contemplation of the present invention to provide four or more five-cycle
 repetitive movements in multiples of two during each revolution. While a
 full five-cycle movement will be performed in each of the eight cylinders
 during each revolution, the start and end for each pair of mirror image
 cylinders will be different, being effectively displaced 90.degree. from
 one to another.
 However, because the cam contours and the resultant piston movements are
 modified in relation to simple harmonic motion from the moment of ignition
 to the moment of the establishment of maximum pressure in the piston
 movement graph shown in FIG. 12, the first 30.degree. of cam movement has
 been transposed to the end so that the area of the graph where ignition
 occurs will be shown in continuity. The lines indicated at i and o in the
 graph of FIG. 12, represent the positions of the inner surfaces of a pair
 of first inlet and outlet pistons 26 and 28 respectively within the
 associated first cylinder 14 during a 360.degree. turn of the cams 32 and
 36. The lines indicated at i' and o' in the graph of FIG. 12, represent
 the positions of the inner surfaces of a pair of second inlet and outlet
 pistons 26' and 28' respectively within the associated second cylinder 14'
 during a 360.degree. turn of the cams 32' and 36'.
 In the graph shown in FIG. 12, the first pistons 26 and 28, and the second
 pistons 26' and 28', are in the positions at the end of compression shown
 in FIG. 2 at the 310.degree. cam position. The cam surfaces 72 and 78, and
 72' and 78', are modified during the expansion cycle so as to accomplish a
 movement of each first piston 26 and 28, and second piston 26' and 28',
 respectively which is different from simple harmonic movement. The
 difference is that the cam surfaces 72 and 78, and 72' and 78', are
 modified to provide that the first pistons 26 and 28, and second pistons
 26' and 28', respectively stay in the position of FIG. 2 or nearly so
 without materially increasing the cylinder volume for a period longer than
 is provided by simple harmonic motion. This modification enables ignition
 to occur after the minimum volume condition is reached rather than before
 as is the case with engines tied to simple harmonic motion.
 It will be understood that where ignition occurs before minimum volume is
 reached, the pressure will increase as a result of the expenditure of
 power as the volume is decreasing so that negative work results. By
 allowing compression to proceed to minimum volume conditions without
 ignition, this negative work is eliminated.
 The dwell or substantial dwell at minimum volume or nearly so continues for
 a time period sufficient to enable maximum pressure to develop in the
 working portion 20 of the first cylinder 14, and in the working portion
 20' of the second cylinder 14', before or substantially before the
 expansion or power cycle begins. In contrast, engines tied to simple
 harmonic motion begin the expansion cycle before the time necessary to
 ensure that maximum pressure can be established and the increase in volume
 at the beginning of the expansion cycle has the effect of limiting the
 maximum pressure that can be established during the beginning movements of
 the expansion cycle.
 The preferred starting position of the first inlet and outlet pistons 26
 and 28, and second inlet and outlet pistons 26' and 28', in relation to
 the first inlet and outlet cylinder ports 18 and 24, and second inlet and
 outlet cylinder ports 18' and 24', respectively at the beginning of the
 power or expansion cycle is shown in FIG. 2. The first pistons 26 and 28,
 and second pistons 26' and 28', have just completed a compression cycle
 and each is at a position equivalent to top dead center or nearly so. As
 previously indicated, preferably combustion has been substantially
 completed and maximum pressure has been generated as the power cycle
 commences with the movement of the first pistons 26 and 28 away from one
 another, and with the movement of the second pistons 26' and 28' away from
 one another. The power cycle is characterized by substantially equal and
 opposite balanced movements of the first pistons 26 and 28, and second
 pistons 26' and 28', until they substantially simultaneously reach their
 respective port cut-off positions, as shown in FIG. 3. More importantly
 during this movement, the first inlet piston 26 moves in more exactly an
 equal and opposite direction with respect to the second inlet piston 26'
 and this same balanced relationship exists between the first outlet piston
 28 and the second outlet piston 28'. As best shown in FIG. 12, the dwell
 period is approximately 20.degree. of cam rotation and the power cycle is
 completed after approximately 60.degree. of rotational movement of the
 cams 32 and 36, and cams 32' and 36', thereafter.
 It will be understood that precise simultaneous movements of the first
 pistons 26 and 28, and second pistons 26' and 28', at the end of the
 expansion stroke would require that both first pistons 26 and 28, and
 second pistons 26' and 28', respectively be brought to a halt as the
 cut-off position is reached. It is possible and preferred to continue the
 outward movement of the first outlet piston 28, and second outlet piston
 28', beyond its outlet port cut-off position while the first inlet piston
 26, and second inlet piston 26', is being brought to a halt at its inlet
 cut-off position. While this difference will make inlet pistons 26 and 26'
 out of balance with outlet pistons 28 and 28' respectively, balance is
 still obtained by virtue of the aforesaid balanced relationship between
 inlet pistons 26 and 26' and outlet pistons 28 and 28'. Consequently, the
 beginning of the exhaust cycle, as best shown in FIG. 4, is characterized
 by a final movement of the first inlet piston 26, and second inlet piston
 26', into its inlet port cut-off position as the outlet ports 24, and 24',
 are opened to initially relieve the pressure within working portion 20,
 and 20', of the first cylinder 14, and second cylinder 14', respectively.
 The first inlet piston 26, and second inlet piston 26', is now in a
 position to move entirely through the working portion 20, and 20', of the
 associated cylinder to positively displace all of the spent gases therein
 outwardly through the open outlet ports 24, and 24'.
 The initial positive displacement movement of the first inlet piston 26,
 and second inlet piston 26', takes place simultaneously with the movement
 of the first outlet piston 28, and second outlet piston 28', respectively
 into its outlet end position. During this movement, a balanced
 relationship exists due to the equal and opposite movements of pistons 26
 and 26' and that of pistons 28 and 28'. The next movement during the
 exhaust cycle is by the inlet piston 26, and 26' while the outlet piston
 28, and 28', respectively is retained in its outlet end position. The
 inlet piston 26, and 26' moves completely through the working portion 20,
 and 20', of the associated cylinder 14, and 14', respectively until it
 substantially reaches the position shown in FIG. 5. This movement
 positively displaces all of the spent gases within the working portion 20,
 and 20', of the associated first cylinder 14, and second cylinder 14',
 respectively but leaves the gas volume between the two pistons 26 and 28,
 and 26' and 28', respectively. The last movement in the exhaust cycle is a
 relative movement of the two pistons 26 and 28, and 26' and 28', toward
 one another into a position substantially in abutting relation with one
 another so as to positively displace all of the gas therebetween through
 the open exhaust ports 24, and 24'. As shown, the two pistons 26 and 28,
 and 26' and 28', reach the abutting relationship with the outlet piston
 28, and 28', having moved almost to its outlet port cut-off position. It
 could be at any position between the outlet end position and the outlet
 port cut-off position thereof. During this movement, the outlet ports 24,
 and 24' are effectively closed and substantially the last volume of gas
 between the two pistons 26 and 28, and 26' and 28' is positively displaced
 through the outlet ports 24, and 24' as they are closed. The final
 position is shown in FIG. 6 and it can be seen from FIG. 12 that, during
 the exhaust cycle, the initial movement of the outlet piston 28, and 28',
 is completed within approximately 28.degree. of rotational cam movement,
 the movement of the inlet piston 26, and 26', through the working portion
 20, and 20', of the associated first cylinder 14, and second cylinder 14',
 is completed in approximately 80.degree. of rotational movement and the
 final movement of the outlet piston 26, and 26', is accomplished
 thereafter in approximately 72.degree. of rotational movement. A
 continuous balance across the central plane is obtained throughout the
 movements due to the equal and opposite relationship between pistons 26
 and 26' and pistons 28 and 28'.
 The transfer cycle begins with the pistons 26 and 28, and 26' and 28',
 disposed in substantially abutting relation within the associated first
 cylinder 14, and second cylinder 14', as shown in FIG. 6, which is the
 same as the position at the end of the exhaust cycle. The transfer cycle
 is characterized by a movement of the inlet and outlet pistons 26 and 28,
 and 26' and 28', together in substantially abutting relation from the
 position shown in FIG. 6 into the position shown in FIG. 7, wherein the
 inlet piston 26, and 26', is in the inlet end portion thereof. This
 movement is accomplished in approximately 52.degree. of rotational cam
 movement.
 When the two pistons 26 and 28, and 26' and 28', reach the end of the
 transfer cycle, as shown in FIG. 7, they are now ready to begin the intake
 cycle.
 The intake cycle in accordance with the improvement of the present
 invention begins after the transfer cycle with the pistons 26 and 28, and
 26' and 28', in the position shown in FIG. 7. The initial movement of the
 intake cycle is a movement of the outlet piston 28, and 28', from the
 position shown in FIG. 7 through the working portion 20, and 20', of the
 associated first cylinder 14, and second cylinder 14', and into the outlet
 end position thereof, as shown in FIG. 9.
 This movement fills the volume between the two pistons 26 and 28, and 26'
 and 28', with a fresh charge of air coming from the open inlet ports 18,
 and 18', which also communicates with the open outlet ports 24, and 24'.
 The next movement which takes place in the intake cycle according to the
 present improvement is a movement of the inlet piston 26, and 26', from
 the inlet end position thereof into the inlet port cut-off position
 thereof as shown in FIG. 10. At the end of this movement, the
 communication of the fresh charge of air between the pistons 26 and 28,
 and 26' and 28', is cut off from the inlet ports 18, and 18'. As the inlet
 piston 26, and 26' passes the inlet port cut-off position, the charge is
 still communicated with the outlet ports 24, and 24', but the outlet
 piston 28, and 28', begins a movement away from its outlet end position.
 As the inlet piston 26, and 26', passes the cut-off position, a shock wave
 of displaced air is sent through the open outlet ports 24, and 24', into
 the exhaust system by the movement of the displaced air volume. The air
 dilutes the exhausting gases and thus dilutes the pollution content of the
 exhausting gases. The intake cycle ends as the inlet piston 26, and 26',
 reaches the compression position thereof simultaneously as the outlet
 piston 28, and 28', reaches the outlet port cut-off position thereof, as
 shown in FIG. 11.
 Consequently, the compression positions of the pistons shown in FIG. 11 at
 the start of the compression cycle with the volume of fresh air is trapped
 within the working portion 20, and 20', of the associated cylinder which
 is less than the full volume of the working portion 20, and 20', of the
 associated first cylinder 14, and second cylinder 14'. The compression
 cycle includes movements of both pistons 26 and 28, and 26' and 28'.
 During this movement, the outlet piston 28, and 28', moves a greater
 distance than the inlet piston 26, and 26'. The displaced volume during
 the power cycle is more than the displaced volume during the compression
 cycle and hence the increased expansion obtains increased efficiency.
 The initial movement of the outlet piston 28, and 28', is accomplished in
 70.degree. of rotational cam movement, the movement of the inlet piston
 26, and 26', into the working portion 20, and 20', of the associated first
 cylinder 14, and second cylinder 14', is accomplished in 33.degree. of
 rotational movement, and the final movement of the outlet piston 28, and
 28', is accomplished in 13.degree. of rotational cam movement. During the
 compression stroke, the movements of the two pistons 26 and 28, and 26'
 and 28', together into the combustion positions thereof is accomplished in
 40.degree. of rotational cam movement.
 While the cyclic movements described above are preferred in the broadest
 aspects of the present invention, the cyclic movements can be the basic
 movements as described in the basic five cycle '140 patent or the cyclic
 movements of the improvement '802 patent.
 It thus will be seen that the objects of this invention have been fully and
 effectively accomplished. It will be realized, however, that the foregoing
 specific embodiment has been shown and described for the purpose of this
 invention and is subject to change without departure from such principles.
 There, this invention includes all modifications encompassed within the
 spirit and scope of the following claims.