A crank or a crankshaft is a device for the interconversion of linear and rotary motion. Crankshafts are basic machine elements and are integral to the function of a great variety of mechanical and hydraulic devices. Some crankshaft devices have an arrangement of conrod or yoke, attached to a piston situated in a chamber, these elements form a reciprocating arrangement wherein fluid or gas is moved as a result of crankshaft rotation, or wherein fluid or gas movement results in crankshaft rotation.

Crankshaft actuated piston pumps and piston engines such as; CI engines, SI engines, sterling cycle engines and heat pumps are often required to operate under a wide range of conditions. Various crankshaft rotational speeds are required in order to achieve a desired volume of fluid or gas movement or pressure; or in reverse, varying pressures and volumes of fluid or gas effect, via a piston, the rotational characteristics of a crankshaft.

A traditional crankshaft that drives, or is driven by, piston movement has a fixed crankpin radius, and thus a fixed swept piston volume, per crankshaft rotation. Therefore, the choice of crankpin radius is in many cases a design compromise that reflects the estimated average or mean operating condition of piston operation. A crankpin that has the capability to alter its effective radius, during operational rotation, can avoid some of the inefficiency and inflexibilities that are inherent in traditional fixed radius, crankshaft devices.

Prior art examples of crankshafts that employ radially adjustable crankpins, have in many cases a variety of undesirable features, such as those using hydraulic fluid pressure for crank radius alteration, for example U. S. Pat. No. 98/00466 and U. S Pat. No. 6,167, 851, the disadvantage being, that the hydraulic seals required in such devices often fail under the pressure required for sustained operation. Furthermore, the relatively high pressures required to alter the crankpin radius whilst the crankpin itself is under full operational load, necessitates a large hydraulic pump.

Mechanically adjustable radius crankpins, such as, US patent 4, 887, 560 require a large number of precision components, many of which are constantly engaged in the load path between piston and crankshaft journal, thus resulting in a complex and costly solution. Furthermore, many examples of previously disclosed adjustable crankpins have either no means, or relatively complex means for the counter-balancing of the changing forces, resulting from the radially adjustment of the crankpin.

Crankshafts are frequently employed in wide variety non piston applications, such as machines involved in manufacturing processes e. g. stamping, forging, pressing, cutting, sawing, mixing and shaping. Also envisaged is the radial displacement of propellers or impellers.

Furthermore, a variety of household devices, devices used for physical exercise and transport devices also incorporate cranks and crankshafts. The present invention is also suitable for utilization or inclusion in the aforementioned machines and devices.

According to the present invention there is provided a crank or crankshaft with at least one adjustable crankthrow or crankpin and counterbalance means wherein the position of the counterbalance means is adjusted when the position of the crankpin relative to the end journals of the crankshaft is altered.

In an embodiment of the present invention there is provided a crank or crankshaft with at least one adjustable crank throw or crankpin, whereby adjustment of the crank or crankpin alters the throw of the crankshaft, and counterbalance means are provided to mitigate any rotational imbalance when the crankshaft is in use, characterised in that the position of the counterbalance means is automatically adjusted to compensate for any change in the throw of the crankshaft.

The invention is further characterised in that the inertial energy of the crank or crankshaft is utilised to effect alteration to the relationship between crankshaft throw and counterbalance means. Thus, since the inertial energy contained in the crank or crankshaft and counterbalance means is directed into force used to move the said crankshaft throw, a direct correlation exists between the inertia and the energy available to overcome the centrifugal forces.

The invention is further characterised in that the inertial energy of the crankshaft is utilised to effect alteration to the crankshaft throw.

Advantageously the inertial energy of the crankshaft is also utilised to effect alteration to the position of the counterbalance means.

The present invention also possesses the ability to provide, whilst rotating a crankpin radius offset that is zero in value or measurement.

The foregoing represents the preferred embodiments of the invention.

Variations and modification of the foregoing embodiments will be apparent to persons skilled in the art without departing from the inventive concepts disclosed herein. All such modifications and variations are intended to be within the scope of the invention as illustrated and described herein The invention to be claimed is as shown in figures ; la, Ib and I c, and the specific description relating to these figures herein. A further embodiment is claimed with reference to figures; la, lc and 2 and the specific description relating to these figures herein. A third embodiment is claimed with reference to figures ; 1 a, 1 c and 3 and the specific description relating to these figures herein. A fourth embodiment is claimed with reference to figures; la, Ic and 4 and the specific description relating to these figures herein. A fifth embodiment is claimed with reference to figures ; la, lb, Ic and 5 and the specific description relating the description herein. A sixth embodiment is claimed with reference to figures ; la, lb, lc and 6 and the specific description relating to these figures herein. A seventh embodiment is claimed with reference to figures ; la, lb, Ic, 7a, 7b and 7c and the specific description relating to these figures herein. An eighth embodiment is claimed with reference to figures ; la, lb, lc, 7a, 7b, 7c, 8a and the specific description relating to these figures herein. A ninth embodiment is claimed with reference to figures ; la, lb, lc, 7b, 7c, 9a, 9b, and 9c and the specific description relating to these figures herein. A tenth embodiment is claimed with reference to figures ; 1 a, 1 c, 7b, 7c, 9a, 9b, 9c, lOa, lOb and lOc and the specific description relating to these figures herein. An eleventh embodiment is claimed with reference to figures ; la, lc, 7b, 7c, 9a, lOa, and 11 and the specific description relating to these figures herein. A twelfth embodiment is claimed with reference to figures ; la, lc, 7b, 7c, 11 and 12 and the specific description relating to these figures herein. A thirteenth embodiment is claimed with reference to figures ; la, 1 c, 7b, 7c, and 13 the specific description relating to these figures herein. A fourteenth embodiment is claimed with reference to figures ; la, 1 c, 7b, 7c, and 14 the specific description relating to these figures herein.

The invention will be now described by way of example with reference to the accompanying drawings in which: Figure 1 a is an exploded isometric view of the first embodiment Figure 1b is an isometric view of the assembled first embodiment Figure 1 c is a cross-sectional view of the assembled first embodiment Figure 2 is an isometric view of the second embodiment illustrating axially and radially arranged ratchets and pawls used for crankpin actuation.

Figure 3 is an isometric view of the third embodiment illustrating axially arranged lobes and pawls used for crankpin actuation.

Figure 4 is an isometric view of the fourth embodiment illustrating radially arranged lobes and pawls used for crankpin actuation.

Figure 5 is a cross-sectional view of the fifth embodiment illustrating the use of a single spindle-journals and crankpin with integrated counterweights and integral crankpin guides.

Figure 6 is a cross-sectional view of the sixth embodiment illustrating an internally threaded crankshaft end.

Figure 7a is an isometric view of a partial assembly illustrating the seventh embodiment with a single-throw crankshaft, with permanently engaged crankpin actuation means.

Figure 7b is an exploded isometric view of the seventh embodiment.

Figure 7c is a cross-sectional view of the seventh embodiment.

Figure 8a is cross-sectional view of the eighth embodiment illustrating the use of radial teeth to be used for indirect synchronised braking.

Figure 8b is an exploded isometric view of the eighth embodiment illustrating brake synchronisation drive shafts.

Figure 9a is cross-sectional view of the ninth embodiment illustrating the use of ratchets and pawls to effect crankpin actuation.

Figure 9b and 9c are isometric views of the ninth embodiment illustrating axially and radially ratcheted tooth equipped bevel gears.

Figure lOa is a cross-sectional view of the tenth embodiment illustrating the use of a single spindle, operating a synchronised double crankpin crankshaft, supported with static spindle bearing housing.

Figure lOb and lOc are isometric views of the tenth embodiment illustrating fully and a partially toothed bevel gear disc brakes.

Figure 11 is a cross-sectional view of the eleventh embodiment illustrating the use of a rotating spindle bearing housing which also rotates with bevel gears and hydrodynamic and electrical resistance is employed for spindle rotation.

Figure 12a is an exploded isometric view of the twelfth embodiment illustrating the use of a dual criss-cross thread, not unlike a"yankee screwdriver type shaft", single spindle, operating a synchronised double crankpin crankshaft.

Figure 12b is an isometric view of an assembly illustrating the twelfth embodiment.

Figure 13 is an exploded isometric view of the thirteenth embodiment illustrating the use of a crank with a sphere ended crank.

Figure 14 is an exploded isometric view of a crankshaft/crankpin supported and driven on one side only, illustrating the fourteenth embodiment.

The first embodiment of the present invention is illustrated in figures 1 a, lb and le. Crankpin 1 is provided with a cylindrical portion 2 for the rotatable attachment of a conrod, yoke or device. At each end, and perpendicular to the axis Y-Y of crankpin 1, are helically threaded bores 3 and parallel profiles 5. Inserted into the helically threaded bores 3 are helically threaded portions 4 of crankpin and counterweight actuation lead- screw spindles 6 and 7 (Referred to hereon in as spindles). The helically threaded lead-screw portions 8 of the two spindles 6 and 7 are helically opposite in direction to helical thread portions 4 of spindles 6 and 7, and correspond to helically threaded bores 9, in counterweights 10, into which spindles are inserted. Spindles 6 and 7 have attached dual direction ratchet arrays 11, which correlate to pawls 12 and 13. The crankshaft ends 14 are equipped with spindle-journals 15, counterweight guide-holes 16, and parallel profiles 17. Spindles 6 and 7 are located and retained in spindle- journals 15 and counterweights 10 are located via guide-rods 19 into guide- holes 16. Parallel profiles 5 locate with a. minimum of play, within parallel profiles 17 of crankshaft ends 14. Both parallel profiles being perpendicular to axis X-X.

In operation, all parts with the exception of pawls 12 and 13 and housing 20 are rotated in unison, in a unified direction, around an axis X-X. The said rotation is a result of either the connection of one, or both crankshaft ends 14, to a prime mover, or by the action of ; a conrod, a yoke, or a reciprocating or rotating linkage that is attached rotatably or rigidly to the cylindrical portion 2 of erankpin 1.

In order to increase the distance between the axis Y-Y of the cylindrical portion 2 of crankpin 1 and the axis common to crankshaft ends X-X, pawls 13 are moved towards a position where a simultaneous engagement of teeth on ratchet array portions 18 can occur, thus intermittently rotating spindles 6 and 7 around axis A-A and B-B respectively. The said rotation of spindles 6 and 7, driving crankpin 1 and crankpin counterweights 10 away from the axis X-X due to the relationship between counter rotating thread portions 8 and parallel guides 19. When a sufficient distance between axis X-X and Y-Y is achieved, pawls 13 are removed from an engagement position. In order to reverse the effects of the engagement of pawls 13, pawls 12 are engaged for a similar number of crankshaft rotations.

In a second embodiment as illustrated in figures la, le and 2, wherein employed as an alternative to dual direction ratchet arrays 11 there are both axially and radially contra-directional arranged ratchet arrays 211 for pawls 212 and 213 to engage with.

In a third embodiment as illustrated in figures la, lc and 3, wherein employed as an alternative to dual direction ratchets 11 there are radially arranged lobe like teeth 311, and as an alternative to the engagement pawls 12 and 13 there are lobe engagement paddles 312 and 313.

In a forth embodiment as illustrated in figures la, lc and 4, wherein employed as an alternative to dual ratchets 11 are axially arranged lobe like teeth 411, and as an alternative to the engagement pawls 12 and 13 are lobe engagement paddles 412 and 413.

In a fifth embodiment as illustrated in figures la, lb, lc, and 5, wherein: crankpin 1 is replaced with crankpin 501; one crankshaft end 14 is replaced with crankshaft end 514 which features a single journal 515; and spindle 6 is replaced with alternative spindle 506. The alternative crankpin 501 features integral counterweight 544 and integral parallel guide 545.

The opposing crankshaft end 546 is equipped with rotating parallel guide-pin 547 on which the crankpin 501 can slide with use of bearings 548 and 549, thus maintaining axis Y-Y parallel to X-X. Operation is as substantially described in the first embodiment with the exception that only one spindle needs to be governed in order to alter the distance Y-Y relative to X-X.

In a sixth embodiment as illustrated in figures la, lb, Ic and 6, wherein: crankpin 1 is replaced with crankpin 601; crankshaft ends 14 are replaced with crankshaft ends 614, which features a helically threaded bore 617 into which thread 604 of alternative spindle 606 mates. The said crankpin 601 has journals 615 at opposing ends through which the said spindle 606 is located with the ability to rotate. The counterweight lead-screw thread 608 is opposite in direction and not necessarily of the same pitch (and maybe of a variable pitch) as that of thread 604 in order to compensate for crankpin 601 radial displacement. Spindle 606 rotates about A-A and is equiped with dual ratchet 11. Operation is as substantially described in the first embodiment with the exception being that the engagement pawls 12 and 13, and any pawl engagement device, including any damping device employed, utilises a variable radius method, i. e. alter the relative distance from axis X-X in order to be able to engage in ratchet portions 18 and 19 at any given radius.

In a seventh embodiment as illustrated by figures la, lb, lc, 7a, 7b and 7c wherein as alternative to the pawls 12 and 13 which intermittently engaged with dual ratchet arrays 11 are bevel gears 712 and 713, which are permanently engaged upon gear pinions 711. Alternative to crankshaft ends 14 are crankshaft ends 714, which incorporate cylindrical guide-sleeves 717. Alternative to crankpin 1 is crankpin 701, which features at opposing ends, semi cylindrical profiles 705 that locate within cylindrical guide sleeves 717. The spindles 706 and 707 are assembled within the crankshaft ends 714 with bearings 732 and journal end-plates 733, (not shown are necessary fixings required to hold journal end-plates). To balance the bevel gear pinions 711 are pinion-counterweights 734. Balancing the moving- counterweight 710 when crankpin 701 is at zero-offset is static counterweight 731, which is fixed to crankshaft end 714. Bearings 721 and 722 are located upon cylindrical surfaces 753 and flanges 750 of crankshaft ends 714, and cylindrical surfaces 751 of flange-ends 752. Bevel gears 712, and 713, which are mounted upon bearings 721 and 722 are provided with cylindrical surfaces 724 and 725. The drum brake shoes 727, 728, 729 and 730 are equipped with friction material 726.

In order to increase the distance between the axis Y-Y of cylindrical portion 702 of crankpin 701 and the axis X-X, a sufficient intermittent or continuous pressure on the drum brake shoes 728 and 729 is applied upon the cylindrical surfaces 724, while the collective assembly is being rotated.

This results in a differential in rotational speed between bevel gears 713 and 712 which causes bevel gears pinion 711 and thus the spindles 706 and 707 to rotate about axis A-A and axis B-B respectively, thus driving crankpin 701 and counterweights 710 away from axis X-X. Once the desired distance is achieved between the axis Y-Y of cylindrical portion 702 of crankpin 701 and the axis X-X, the pressure from the drum brake shoes 728 and 729 is released.

In order to reverse the effect of the pressure from the drum brake shoes 728 and 729, sufficient continuous or rapidly cycled pressure from the<BR> drum brake shoes 727 and 730 is applied to the cylindrical surfaces 725.

Not shown are mechanical or electrical devices including any A. B. S. related devices that may be used in order to synchronise the braking effort between brake shoes.

In an eighth embodiment as illustrated by figures l a, lb, lc, 7a 7b, 7c, 8a and 8b, wherein employed as an alternative to the bevel gears 712 and 713 with cylindrical surfaces 724 and 725 are bevel gears 812 and 813 which are provided with external, radial, equidistant teeth 841 and 842. Parallel to the crankshaft axis X-X are brake effort synchronising drive shafts 838 and 840, which rotate about axes E-E and F-F respectively. Radial teeth arrays 835 and brake disc 837 are attached to drive shaft 838. Radial teeth arrays 836 and brake disc 839 are attached to drive shaft drive 840. Teeth arrays 841 are linked to teeth arrays 835 and teeth arrays 842 are linked to teeth arrays 836. The method of linking (not shown) can be direct or with intermediately gearing, or positively engaging flexible belt or chain.

Spindle 807 and the corresponding internal thread in crankpin 801 has helical thread portions in a thread rotation arrangement that is opposite to the relevant thread portions upon spindle 706. In order to increase the distance between the axis Y-Y of cylindrical portion 802 of crankpin 801 and the axis X-X, brake disc 837 is continuously or intermittently braked.

Once the desired distance is achieved between the axis Y-Y of cylindrical portion 802 of crankpin 801 and the axis X-X common to crankshaft ends 714, the forces upon brake disc 837 or any forces upon the shaft 838 are released. In order to decrease the distance between the axis Y-Y and the axis X-X brake disc 839 is stopped or reduced in relative speed during rotational operation. Thus the rate of braking of both bevel gears 812 are ensured to be equal as they are physically positively connected. Similarly, with both bevel gears 813, thus ensuring parallel movement of crankpin 801 relative to axis X-X.

Drum brakes, ratchets and pawl means, fluid impellors, and electrical resistance means are deemed suitabie in order to replace the function of brake discs 837 and 839. A coaxial arrangement between axis F-F and axis E-E is also envisaged.

In a ninth embodiment as illustrated by figures la, lb, lc, 5, 7b, 7c, 9a, 9b and 9c, wherein employed as an alternative to the bevel gears 712 and 713 are bevel gears 912 and 913 which are provided with axial ratchet teeth 924 and radial ratchet teeth 925 respectively. The said ratchet teeth being braked, when required by pawls 927 and 928 respectively. As within figure 5 one end of the crankpin 901 slides on a rotating parallel axis guide mechanisms 547 and 546 with aid of bearings 948. Operation is as substantially described in the first and seventh embodiments with the exception that only one spindle needs to be governed in order to alter the parallel distance Y-Y relative to X-X.

In a tenth further embodiment of the currently disclosed invention as illustrated with the aid of figures la, 1 c, 5,7b, 7c, 9a, 9b, 9c, 10a, 10b and 1 Oc, figure 1 Oa illustrates a crankshaft with two adjustable radius crankpins 1001 and 1054. A single centrally located dual crankpin spindle 1006 is mounted on bearing ring 1055, which is held concentric to axis X-X with stationary housings 1057 and 1058. Both said housings being attached to crankshaft end housings 20. Bevel gears 1024 and 1025 rotate with bearing ring 1055 located in static housings 1057 and 1058. Assisting the rotation of bearing ring 1055 are bearings 1056. Rotating parallel axis guide<BR> mechanisms 547 and 546 hold rotatable the non-threaded ends of crankpins 1001 and 1054 in a similar method as illustrated in figure 5. The dual crankpin spindle 1006 is facilitated with two symmetrical opposing threads 1004 and 1008 onto which crankpins 1001 and 1054 with relevant internal threads are located.

In figure 10a and 10b cylindrical surfaces 724 and 725, from figure 7, are replaced with brake type discs 1024 and 1025 and drum brake shoes 727 and 730, and 728 and 729 are replaced by a friction brake pad arrangement 1027 and 1030.

Figure l Oc shows a partially toothed bevel gear 1041 that maybe used in place of a fully toothed bevel gear e. g. 1025, depending on the distance of crankpin off-set required.

In operation all parts are rotated with the exception of housings and braking means. The distances between axes Z-Z and X-X and Y-Y and X- X are increased when bevel gear 1025 is reduced in relative speed by an intermittent or continuous braking effort, applied by brake pads 1027, upon the disc 1059. The said disc being integral or fixed to bevel gear 1025. In order to decrease the distance between axis Z-Z and X-X, and Y-Y and X- X an intermittent or continuous braking effort is applied by brake pads 1030 to the brake disc 1060 which is integral to bevel gear 1024.

The use of a single spindle 1006 negates the necessity to synchronise a braking or stopping action, furthermore the direction and pitch of thread 1008 relative to 1004 can be non symmetrical and or of a different pitch in order to govern the crankpin radius of 1001 relative to 1054 in a disproportional manner.

In a further embodiment, the eleventh as illustrated by figures 1 a, 1 c, 7b, 7c, 9a, lOa and 11 wherein static housings 1057 and 1058 are replaced with a rotating housing 1157. This revolves about axis X-X in a similar method as shown in figures 7b and 7c therefore bearings 1055 are not required.

Replacing braking disc 1024 with hydrodynamic impeller blades 1124, used to induce hydrodynamic braking, and disc 1025 with stator 1125 used to induce electrical braking. Operation of this embodiment is as described in the tenth embodiment with the exception of the methods of braking.

A twelfth embodiment is shown in figures la, 7b, 10a, 11,12a and 12b.

Spindle 1206 replaces spindle 1006. The said spindle 1206 has dual directional threads 1204 and 1208 running or overlapping the same spindle length. As in embodiment 10, the use of a single spindle 1206 negates the necessity to synchronise a braking or stopping action and furthermore the direction and pitch of thread 1208 relative to 1204 can be used to govern the radius of crankpin 1201 relative to the radius of crankpin 1254.

Crankpins 1201 and 1254 can be retained or guided relative to each other.

This embodiment also envisages that the spindle can be used as an alternative to the spindles in all of the embodiments including single crankpin variations where one thread is used for the movement of counterweight.

In the thirteenth embodiment as illustrated in figure 13 a crankpin 1301 with a sphere is envisaged where more than two plane flexibility output or input is required or delivered. This embodiment also envisages that the said crankpin 1301 can be used as an alternative to the spindles in all of the single crankpin embodiments In the fourteenth embodiment as illustrated in figure i4 a crankpin 1401 that is driven or supported from one side is envisaged where more than two plane flexibility output or input is required or delivered. This embodiment also envisages that the said spindle 1401 can be used as an alternative to the crankpins in all of the single crankpin embodiments.