The present invention relates to a system for the reversible transformation of a reciprocating motion in a rotary motion and, more precisely, to a system for the reversible transformation of a reciprocating motion in a rotary motion which incorporates a spiral rotor.
An internal combustion engine is known from U.S. Pat. No. 7,942,115 which describes a system for converting a reciprocating rectilinear motion into a rotational motion. The system comprises an assembly of internal combustion cylinders, each of which has a rod which pushes a slider over the surface of a rotor. The rotor has a cross section with a spiral profile, and in such a way that the slider follows the surface and performs a compression and an expansion step. This solution of the prior art has proved satisfactory, although it has the disadvantage of that the thrust of the piston in the cylinder is based solely on the pressure of the combustion gas. This is a realization that decreases but does not solve the problems of environmental pollution, and is also relatively inefficient.
Consequently, there is a need to improve the operation of the internal combustion cylinder and spiral profile rotor system, in order to reduce the aforementioned problems of environmental pollution, and improve efficiency and, therefore, lower fuel consumption.
The present invention seeks to solve the abovementioned problems and drawbacks of the state of the art by providing a new energy supply system for the transformation of a reciprocating rectilinear motion in a rotational motion.
Thus, the present invention provides a system for a reversible transformation of a reciprocating motion in a rotary motion which comprises one or more actuating cylinders and a rotor with a spiral section, each actuating cylinder of the plurality of actuating cylinders comprises a first and a second hydraulic cylinders internally assembled and independently slidable one with respect to the other, and wherein each hydraulic cylinder is coupled to a respective spring, the arrangement being such that the system provides for the rotation of the rotor each actuating cylinder uses separately a first spring of a first hydraulic cylinder and subsequently a second spring of said second hydraulic cylinder, for urging a tubular rod coupled to said first and second hydraulic cylinders, wherein said tubular rod at the opposite end thereof continuously contacts the surface profile of said spiral rotor and causing the rotation thereof.
According to the present invention, a system for operating a rotor with a spiral profile comprises one or more actuating devices, each of which comprises an arrangement with two independent hydraulic cylinders, each of which has a spring, a tubular rod, and a follower fitted with a wheel or the like. Each spring acts on the corresponding mobile member and slides inside the hydraulic cylinder wherein it is housed. The first sliding member of the hydraulic cylinder is operatively coupled to the first spring. The second sliding member of the hydraulic cylinder is operatively coupled to the second spring. The first spring moves the first sliding member according to a non-synchronous movement with respect to the second sliding member. A tubular rod is selectively coupled to the first sliding member and to the second sliding member alternately. The tubular rod transmits the thrust of the spring to the end of the slider-wheel. The end of the follower-wheel it is urged and slides outwardly of the cylinder due to the expansion of the first spring and, simultaneously, an hydraulic device external to the cylinder produces a hydraulic fluid pressure which it is transmitted to respective hydraulic cylinders, and causing the second spring to be compressed.
The arrangement is such that at each complete revolution of the rotor the said first and second springs alternate the expansion phase thereof: the first spring completes its expansion in a full revolution of the rotor, while the second spring by effect of the hydraulic pressure it is completely compressed in the same revolution period.
The present power device uses the force of the spring as the primary force for performing the useful work.
Thus, the present invention provides a system for a reversible transformation of a reciprocating motion in a rotary motion according to the appended claims.
The present invention has several advantageous aspects here below illustrated.
In a preferred non-limiting embodiment, the system uses two springs of different sizes but having substantially equal pushing force. Each spring acts on the respective sliding member and respective hydraulic cylinder to push the tubular rod which acts through the end of the follower-wheel.
By way of non-limiting example, the slider can be a wheel or, alternatively, also a low friction sliding surface (skid). The slider-wheel always contacts the surface of the spiral shaped rotor profile, thus transmitting the force from the device to the rotor surface transforming it into a driving torque.
It has to be pointed out here that the system of the present invention can use any power device known for conversion/transmission, such as: springs, hydraulic systems, pneumatic systems, electromagnetic systems, and combinations thereof, with the aim of creating the force necessary to compress the springs or to create the torque on the rotor shaft.
As a non-limiting example, the system comprises fixed parts and moving parts. The former include a body of each cylinder, a support plate, and a couple of hydraulic cylinders. On the other hand, the moving parts comprise two springs, a tubular push rod, a rotating or sliding follower mounted at the end of the rod, and two sliding members which slide one relative to the other and relative to the respective hydraulic cylinders, the sliding members being housed inside said cylinder body.
Furthermore, auxiliary parts external to the above illustrated system are provided, such as for example one or more hydraulic pumps and relevant hydraulic fluid regulator/distributor, and pump/pumps reservoir. These parts of the system will be specifically described hereinafter.
Preferably and according to the invention, a plurality of devices as described above can act on a single rotor member. The rotor can have a non-circular profile contact surface.
Thanks to the particular configuration of the spiral rotor, the thrust of each device it is transmitted on the rotor surface, causing the latter to rotate for a complete revolution in an expansion cycle of one of the springs.
The main feature of this system it is the ability to use the expansion phase of one of the springs to carry out useful work, i.e. the rotation of the rotor, while the second spring it is gradually compressed, and all this is achieved in a single rotation of the rotor. Therefore, the present invention utilizes a unique system for switching the actions between the springs: while one expands itself the other it is compressed. This function it is performed simultaneously, that is to say, while a spring is expanding the same produces a driving force onto the rotor giving a rotation force to the latter, and at the same time the other spring (which has expanded in the previous rotation period) it is in the compression phase. The compression of one of the two springs takes place by action of a hydraulic system (or any other similar system already known), and in such a way that the compressed spring will be completely ready to transmit the force to the rotor for the next following revolution of the rotor shaft. This cycle of switching between the springs is repeated for each revolution of the rotor.
The present invention provides noteworthy new solutions with important improvements compared to the most pertinent state of the art U.S. Pat. No. 7,942,115, wherein an application of a rotor with a polar spiral profile combined with an internal combustion thermal unit (cylinder-piston) it is already known.
Advantageously and according to a first inventive aspect of the present invention, in the case of use of the spiral rotor in combination with internal combustion cylinders (cylinder-piston), a circular section (or a constant diameter) surface of the spiral rotor it is provided, and in order to keep the piston in a stopped position at the T.D.C. top dead center (so-called “piston dwelling”) and during the combustion phase, thus obtaining a complete combustion at a constant volume. The same configuration of piston stop it is obtainable at the bottom dead center B.D.C. and for the complete waste/washing/filling phase of the cylinder.
According to another advantageous aspect of the present invention, it is possible to make the surface of the rotor profile in different ways. As a matter of, according to the state of the art document U.S. Pat. No. 7,942,115, the contact surface with the cursor is always a flat surface on which the force generated by the cursor acts perpendicularly. According to the present invention the contact plane of the slider/follower it is inclined and in such a way that different angles of inclination of the slider/follower can be provided, obtaining a greater efficiency, and thus obtaining a number of possible constructive configurations.
According to a further advantageous aspect of the present invention, the cylinder expansion length it is expected to be decided by the constructor according to the project requirements.
According to another advantageous aspect of the present invention, it is possible to provide different embodiments of the system, wherein each of them has a determined arrangement of the actuating devices with respect to the rotor surface. More precisely, by varying the angle of inclination of the actuating devices with respect to the normal direction of the rotor surface it is possible to increase or decrease the value of the force exerted by the actuating devices on the spiral profile, and consequently increase or decrease the torque value of the rotor, while maintaining the cycle phases unchanged.
According to another advantageous aspect of the present invention, it is possible to manage the inclination of the actuating device(s) and, therefore, the direction of the force applied to the rotor, thus obtaining the possibility of varying the stroke of the urging member in a complete revolution of the rotor.
A detailed description of some preferred embodiments of the system for the reversible transformation of a reciprocating motion in a rotary motion of the present invention will now be provided, given by way of non-limiting examples, and with reference to the accompanying drawings, wherein:
Referring now to
The system provides a couple of different sized springs but having an equal thrust force arranged inside a single cylindrical block. Each spring acts on a movable member, housed within a respective hydraulic cylinder, and associated to a tubular rod which transmits the thrust to an end thereof coupled to a rolling slider (bearing). The rolling slider it is urged to maintain a continuous contact with the surface of the spiral rotor profile, creating a torque onto the rotor axis, and thereby causing the rotor to rotate. The hydraulic cylinders have different sizes but the same volumetric capacity.
An external system that supplies the power acts on the respective springs to compress them during each cycle. As non-limiting examples of external systems there are listed here below: a pneumatic system, a hydraulic system, an electromagnetic system.
Referring now to
Both the movable members (2) and (14) of the hydraulic cylinders (12) and (13) are associated with the tubular rod (6) on one side, and on the other side they are associated to respective springs (1). The tubular push rod (6) it is always in contact with the supporting head (4) at one end thereof, while at the other end selectively engages the movable members of the cylinders (2) and (14).
As can be seen in the
Furthermore, it is provided that the rotation of the rod (6) is completed before the beginning of the retraction displacement of the rod (6) towards the inside of the cylinder (11), and by exchanging the engagement from the movable member (2) which has its own spring in the expanded condition with the other movable member (14) with the spring in compressed position. It is necessary to point out here that the toothed region (10′) has a length such as to engage the ring gear (6′) for a period such that the latter rotates of 90 angular degrees.
As illustrated in
With reference to
With reference now to
The toothed region (17) can be made integrally or connected with the disk (10). The disk (10) rotates with the rotor (3) which acts on the hydraulic fluid distributors (8) of the power devices, while the power devices and the accessories are fixed. The toothed region (17) has a length such that it engages the regulator gear (8) making the latter rotating of 90 angular degrees.
As can be seen from
The tubular rod (6) has a notch in order to allow both the movable members (2) and (14) of the hydraulic cylinders (12) and (13) to slide in a uncoupled manner with respect to each other. The contact between the tubular rod (6) and the members (2) and (14) is obtained so that the tubular rod (6) rests on the base of the movable members.
As can be seen from
In the above described displacement of the movable members (2) and (14), the fluid it is expelled towards the tank (19) by the hydraulic cylinders (12) and (13) in each active stroke of the members (2) and (14), caused by pushing the springs (1).
With reference now to
According to the embodiment shown in
It should be noted here that each individual drive device can rotate the rotor (3). Due to the spiral configuration of the rotor (3), the force of each device is transmitted and converted to the rotor (3) in a driving torque causing it to rotate for a complete revolution at each active phase of the driving device.
At the end of the stroke of the tubular rod (6) the latter it is in a position of maximum extension from the cylindrical body (11) and coinciding with a complete revolution of the rotor (3) and via by the slider (5). In this position, the rod (6) is free of any resistance, and it is rotated about its axis by 90 angular degrees, thus detaching from the movable member (2) or (14) to which it is associated until that moment. In this condition, the rod (6) it is ready to engage the other moving member, which has so far compressed the respective spring under the pressure of the hydraulic fluid.
The re-entry displacement and the contacting with the member (2) or (14) has no resistance.
The re-entry of the rod (6) takes place through the rotor (3), which rotating acts with the return ramp (20) on the slider (5), thus pushing the group consisting of the slider (5), the head (4), and the tubular shaft (6) towards the inside of the cylindrical body (11).
As can be seen from
When the rotor (3) rotates under the thrust of each of the actuating devices in the direction of the arrow (counter clockwise in the figure), at least one of the actuating devices engages the portion of the ramp (20). The rotor (3) acts by pushing the head (4) and the tubular rod (6) towards the inside of the cylindrical block (11) through the slider (5). The re-entry of the rod (6) and the head (4) is not impeded by any resistance, and the rod (6) it is brought into contact with the mobile member of the hydraulic cylinder to repeat the rotation cycle. For each cycle the compressed spring expands itself, and the slider (5) it is biased transmitting a torque to the rotor (3) along the curvilinear part (21). This interaction occurs for each actuating device which acts on the rotor (3).
As shown in
While the fluid is pumped under pressure into a respective hydraulic cylinder, thereby effecting the compression of the respective spring, at the same time the fluid is ejected from the other cylinder due to the movement of the movable member which is moving under pressure of the respective spring. The mobile member under pressure of the spring is performing the useful work, i.e. the rotation of the rotor, while the other moving member is in the compression phase of the spring under fluid pressure.
According to this embodiment, a fluid, liquid, or gas is pumped through the distributor (8) through the appropriate passages connected with the hydraulic cylinders (12) and (13). This provides a hydraulic fluid pressure inside the hydraulic cylinder. Since the movable member is the only movable part of the cylinder, the same is moved under fluid pressure, effecting the compression of the respective spring.
As already pointed out, the active phase which makes the rotation of the rotor is carried out during the expansion of the spring. While the rotor (3) has a complete revolution, the spring expands and the thrust towards the rotor (3) is exhausted. During the spring distension phase, the hydraulic fluid contained in the cylinder is expelled from it towards the oil tank. The flow from the pump to the pump takes place through non-return valves.
It should be noted that in the various embodiments of the system of the present invention, the hydraulic fluid can be any fluid, liquid or gaseous. Moreover, the springs can be of various material and can be replaced by other equivalents, they can be compressed by the use of any liquid or gaseous fluid, or by the use of electromagnetic coils, as also any other known system can be used suitable for the purpose.
Referring now to
It should be noted that each drive device of this system has a structure similar to that shown in
It is the external group of devices that inside they are coplanar to the rotor (103). Each actuating device is arranged in the plate (101).
The forces of the respective devices are cumulative. In this way, more power can be supplied to a rotor of the same size with respect to the embodiment of
The number of devices that can be assembled on a rotor depends on its diameter and on the constructive choices. The more groups of devices are mounted on the internal and external profiles of the rotor (103), the more power will be transferred to the rotor. According to this embodiment, the actuating devices operate on the rotor (103) in the manner described above and with reference to
Referring now to
In this configuration the system (200) provides a plurality of devices, some of which are not arranged on the same horizontal plane containing the rotor (203). The system (200) comprises a shaft (230) connected to the rotor (203).
The rotor (203) provides curvilinear profiles both on the horizontal (radial) surfaces and on the outer (tangential) surface containing each retraction ramp (205) and (206), respectively.
More precisely, a first ramp (205) is on an outer surface of the rotor (203). The rotor (203) has a curvilinear spiral profile. One or more actuating devices are arranged both on the horizontal and the vertical plane, to operate on the rotor (203) as said above. Each drive device has a structure as described in
Some drive devices are positioned perpendicular to the rotor surface (203). The effective force of the devices positioned perpendicularly creates a rotation of the rotor (203) in the same direction (as indicated by the arrow) of those generated by the groups of devices arranged in different positions contained in the horizontal plane containing the rotor, and therefore these forces are cumulative with the forces applied to the rotor by the other devices mounted in different configurations.
Moreover, in a further alternative embodiment, three different surfaces of the rotor (203) can be engaged at the same time. The actual forces applied by all drive unit groups are combined to generate rotor rotation.
With reference now to
The actuating device comprises a single spring. A push rod (306) is arranged inside the cylindrical block (311). The spring is arranged inside the cylindrical block between the base of the block and the push rod (306). The push rod (306) carries a slider (5) on the opposite end to that in contact with the spring. An electromagnetic coil (320) is predisposed to spring compression when it operates at a precise moment of the rotor revolution (3). The coil (320) is arranged in the cylindrical block (311). The rotor (3) acts on a switch (not shown) to cause current feeding to the magnetic coil (320) creating an electromagnetic force to compress the spring. The switch interrupts the electric current when the retraction ramp (20) has pushed the push rod (306) inside the cylindrical block, which happens without any resistance because the spring has been compressed by the magnetic force of the coil under current. Since the electric current is interrupted by the coil, the spring is released and pushes the push rod (306) out of the cylindrical block (311). Through the slider (5) the force is transmitted to the rotor (3) causing its rotation, as previously illustrated. The rotor (3) will interrupt the power supply to the electromagnetic coil (320), using the switch. The switch can be controlled by a microprocessor electronic control unit, or by mechanical activation according to the position assumed by the rotor (3) in the rotation.
Therefore, it is possible to simultaneously engaging, on the same rotor, groups of internal combustion cylinders fed with different fuels, arranged on the different profiles of the rotor according to the configuration of
In
Thanks to the configuration described above, a better washing of the cylinder (50) is obtained by expelling the burnt gas remaining in the cylinder and a complete filling of the cylinder with fresh air while the piston is not it moves and, therefore, does not interrupt the described cycle, unlike what happens in the current internal combustion engines.
Both the piston stop solutions to the T.D.C. and to the B.D.C they can be made on the same rotor. In this way, the characteristics and thermodynamic values of the cycles are considerably improved and more effective.
In each embodiment, the outer surface of the curvilinear profile of the rotor is in contact with the slider (5) along a coplanar or orthogonal direction. In other words, the cursor (5) transmits a force to the rotor with an angle of 0° (coplanar) or an angle of 90° (orthogonal) with respect to the plane of the rotor.
In the subsequent embodiments, the force applied to the rotor it is transmitted via slider (5) at a different angle from the rotor plane.
Referring now to
In the system 400 a combination of actuating devices acts on the rotor (403) at the inclined surface (the devices not shown in the figure). The device assembly works with an inclination of 45 degrees relative to the rotor (403) and gives a greater net driving force to the rotor (403). The resulting force it is a force as shown by the F1 arrow. Changing the angle of inclination of the surface (405) of the rotor (403) the net force applied to the rotor (403) will change accordingly as a result of the variation of the angle because the transmitted force it is a vectoral function of direction.
While the angle of inclination can vary from 1 to 89 degrees with respect to the plane of the rotor (403), the relative orientation of the whole assembly of actuating devices can be modified in any position between about 1 and 179 degrees with respect to the plane of the rotor (403) or between −89 and +89 degrees with respect to the normal direction of the surface (405) as indicated by the double arrow G.
According to this system 400, the actuating devices can interact in a direction on the inclined surface (405) or in the opposite mirroring direction on the surface (405′) of the rotor (403), as shown in dashed lines in
In the present embodiment, if the drive unit assembly is positioned orthogonal to the profile (33), in this case, the resulting force is applied with an angle indicated by the arrow F2. In this case, the angle of the profile surface (33) can alternatively vary from about 1 to 89 degrees with respect to the plane and as shown by the dashed surface (435′). Furthermore, the orientation of the device assembly (400) can be comprised at any angle along the double arrow H to provide a variety of different driving forces at different angles, i.e. at any angle corresponding to from about 0 to 180 degrees relative to the plane of the rotor (413).
Referring now to
The outer peripheral surface of the rotor (503) it is a rounded surface (505), and extends substantially 360 degrees from a first point of the surface (503a) of the rotor (503) to a second point of the surface (503b) of the rotor (503). The arc length of the rounded surface (505) depends on the thickness of the rotor (503).
The drive assembly can be arranged in a condition normal to the surface and in any position along the convex surface (505), in the direction indicated by the two-headed arrow D. By way of example, a force can be applied by an actuating device along a line as indicated by the arrow F3.
In this way, a greater net force can be applied by the group of actuating devices (not shown) by adjusting the angle of inclination of the group of devices relative to the plane wherein the rotor (503) resides.
Referring now to
The assembly of actuating devices (not shown) can be oriented in relation to the circular surface of the rotor profile at any position along the surface (515), in the direction of the double arrow E, to have any inclination in relation to the circular surface (515), thus determining the direction of the force of the arrow F4.
Referring now to
According to this embodiment, no spring there is provided to exert the driving force on the rotor (603), but the pneumatic cylinder (601) uses compressed air pressure to act on the piston (602). The piston rod (605) has a rolling slider (606) which acts on the rotor surface (603) causing the latter to rotate.
The compressed air it is injected into the pneumatic cylinder through the solenoid electromagnetic valve (612) which is opened only at a precise moment, i.e. when the piston (602) of the cylinder is at the top dead center T.D.C. (condition shown in the figure). The opening of the valve (612) it is regulated by an electronic control unit or by a simple device via contact managed by the rotation of the rotor (603).
After the injection of compressed air, the solenoid valve (612) it is closed until the rotor (603) makes a complete revolution. At the bottom dead center B.T.M. of the piston (602), the air it is released into the environment or partially recovered from the system.
Referring now to
As can be understood from the figures, by changing the inclination of the actuating device (706) with respect to the rotor surface (703) it is possible to obtain different values of forces and consequently different torque values onto the rotor (703).
More precisely and with particular reference to
It should be noted here that the cycle phases do not change, so that the expansion and compression phase of the device (706) are always connected to the spiral profile of the rotor (703).
According to this configuration it is possible to considerably increase the torque on the rotor axis (703) thanks to the choice of the degree of inclination of the device (706). Moreover, it is also possible to vary the run of the device (706) proportionally to the inclination of the same with respect to the surface of the rotor (703). In this way a longer or shorter stroke can be obtained, according to the constructive needs, but always corresponding to a complete rotation of the rotor (703).
Referring now to
According to this embodiment a new interaction solution there is provided between one or more piston cylinders and an interaction surface of a rotating rotor about its own longitudinal axis of rotation, wherein the rotor has a circular section, and the interaction surface of the rotor with said one or more piston cylinders it is normal to the longitudinal axis of the rotor and has a spiral profile with relevant elevation.
It should be pointed out here that according to further alternative embodiments, the rotor can have one or more interaction surfaces normal and/or parallel to the longitudinal axis of rotation.
According to the present embodiment, the positioning of the cylinder (s) provides that each cylinder it is arranged in a manner wherein the contact point of the rods of each cylinder with respect to the interaction surface of the rotor always has an angle of 90 degrees, i.e. orthogonal to the interaction surface.
This configuration guarantees an ideal distribution of forces on the surface of the rotor, where the same give maximum effect.
This configuration it is applicable both for internal combustion cylinders, or pneumatic or hydraulic cylinders or other equivalent solutions.
The force created by the assembly of the piston-cylinders is in this configuration always applied with a right angle throughout the active phase of the cycle, thus transmitting a better energetic effect with minimum energy losses involved.
With reference now to
According to this embodiment, an interaction surface of one or more cylinder-pistons of a rotor about a longitudinal axis it is provided, the rotor having a circular cross-section, and the interaction surface of the rotor with the said one or more piston cylinders it is normal to the longitudinal axis of the rotor, and the interaction surface has a spiral profile with a relevant lift ramp.
It should be noted here that according to alternative embodiments the rotor can have one or more interaction surfaces normal and/or parallel to the longitudinal axis of rotation of the rotor.
Further, a lever mechanism it is provided which acts during the piston stroke phase at the top dead center T.D.C. in the compression phase. That is, given that the portion of the rotor comprising the spiral profile has a lift ramp with excessive inclination and therefore creates excessive frictional forces during the stroke of the piston, the presence of the lever eliminates such problems during operation.
More precisely, the lever it is connected to the engine block and therefore does not rotate with the rotor. The lever has a fork shape and a relevant slider or follower placed at the fork end. The ramp acts on the slider, while the end of the lever interacts with the slider of the piston rod. While approaching the ramp, the lever rises and returns the piston to the top dead center T.D.C.
As soon as the top dead center of the piston T.D.C. is reached, the lever it is released and returns to the starting position. This solution, albeit simple, has the enormous usefulness of limiting the forces engaged, of generating little resistance to the displacement, and the friction is brought to a minimum.
This configuration is applicable for both internal combustion cylinders, or pneumatic cylinders, or hydraulic cylinders or other solutions equivalent.
It will be apparent to those skilled in the art that the present invention it is susceptible to other modifications in addition to what has been disclosed herein, without departing from the spirit of the present invention and all included in the scope of the appended claims.
Number | Date | Country | Kind |
---|---|---|---|
102016000124647 | Dec 2016 | IT | national |
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/IB2017/057765 | 12/9/2017 | WO |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2018/104923 | 6/14/2018 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
1087240 | Kellington | Feb 1914 | A |
1282824 | Hartson | Oct 1918 | A |
1456479 | McKenzie | May 1923 | A |
1528164 | Nordwick | Mar 1925 | A |
1597474 | Nordwick | Aug 1926 | A |
1810688 | Clark | Jun 1931 | A |
1996710 | Sass | Apr 1935 | A |
2120657 | Tucker | Jun 1938 | A |
2124604 | Bidwell | Jul 1938 | A |
2174664 | Korany | Oct 1939 | A |
2217796 | Dell | Oct 1940 | A |
2249951 | Fulton | Jul 1941 | A |
2450912 | Putnam | Oct 1948 | A |
2496040 | Criley | Jan 1950 | A |
3130716 | Creswick | Apr 1964 | A |
3396633 | Ryzner | Aug 1968 | A |
3510143 | Carpenter | May 1970 | A |
3688751 | Sahagian | Sep 1972 | A |
3841279 | Burns | Oct 1974 | A |
3948607 | Atwood | Apr 1976 | A |
4899853 | Hummel | Feb 1990 | A |
5232666 | Longman | Aug 1993 | A |
5634441 | Ragain | Jun 1997 | A |
5673658 | Allmendinger | Oct 1997 | A |
6449940 | Nagel | Sep 2002 | B2 |
7942115 | Skulic | May 2011 | B2 |
10408201 | Smith | Sep 2019 | B2 |
20030024493 | Beierle | Feb 2003 | A1 |
20070068468 | Irick | Mar 2007 | A1 |
20140245981 | Schnell | Sep 2014 | A1 |
20190032521 | Hirschmann | Jan 2019 | A1 |
20190154016 | Ono | May 2019 | A1 |
Number | Date | Country |
---|---|---|
653623 | Nov 1937 | DE |
654870 | Dec 1937 | DE |
2413947 | Oct 1974 | DE |
4344545 | Jun 1995 | DE |
0318817 | Jun 1989 | EP |
2599084 | Nov 1987 | FR |
457876 | Dec 1936 | GB |
1334091 | Oct 1973 | GB |
199616261 | May 1996 | WO |
2004031576 | Apr 2004 | WO |
2006057018 | Jun 2006 | WO |
Number | Date | Country | |
---|---|---|---|
20200095865 A1 | Mar 2020 | US |