Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
  • F01L5/00—Slide valve-gear or valve-arrangements
  • F01L5/04—Slide valve-gear or valve-arrangements with cylindrical, sleeve, or part-annularly shaped valves
  • F01L5/045—Piston-type or cylinder-type valves arranged above the piston and coaxial with the cylinder axis
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
  • F01L3/00—Lift-valve, i.e. cut-off apparatus with closure members having at least a component of their opening and closing motion perpendicular to the closing faces; Parts or accessories thereof
  • F01L3/20—Shapes or constructions of valve members, not provided for in preceding subgroups of this group

Definitions

• This invention pertains to valves and valve timing for a cylinder of an internal combustion engine.
• Opening and closing of valve holes, as well as the sizes of valve holes, are important considerations in a four-stroke internal combustion engine.
• valve heads are traditionally arranged with two suction or intake valves on one side of the head, and two exhaust valves on the other side of the head.
• Alejandro De Tommaso developed a six valve head having three suction valves and three exhaust valves inside a 90 mm circumference.
• valve head With the conventional multiple valve arrangements very little of the valve head real estate is actually devoted to induction of combustible mixture, particularly since the valve head must also accommodate exhaust valves (and in a manner without interference). Moreover, the exhaust valves protrude into the cylinder and thereby have a tendency to oppose the outflowing of exhaust gases. Moreover, the exhaust valves (including the valve stems) are subjected to intense heat as the exhaust gas escapes .
• the invention pertains to a four stroke
• the exhaust valve is part of an exhaust valve assembly selectively covers an exhaust port
• the exhaust valve assembly includes a ring-shaped portion of a cylinder lining which is configured to selectively obstruct air from escaping radially from the top of the cylinder.
• the exhaust port is opened and closed by the lifting of the exhaust valve assembly (30) by a vertical guillotine-type motion.
• the induction valve is included in an intake valve assembly and is provided on a cylinder head.
• the intake valve assembly has a ring or washer shape.
• the ring shaped induction valve thus provides a single, large opening in a cylinder head for induction of a combustible mixture.
• the timing of both valves is faciliated by a single spring and induction and exhaust gear-like, planar timing bearings.
• Each of the induction timing bearing and the exhaust timing bearing have a earning surface provided thereon to face the other bearing.
• induction timing bearing and the exhaust timing bearing are followed by respective roller tappets.
• the valving and timing arrangement faciliate the flexibility in the design of a combustion chamber.
• Fig. 1 is a partially sectioned, partially exploded front view of an exhaust valve assembly
• Fig. 2 is a sectioned front view of an internal combustion engine showing an exhaust valve assembly and a timing control system for use therewith in accordance with an embodiment of the invention.
• Fig. 3 is a sectioned side view of the engine of the embodiment of Fig. 2.
• Fig. 4 is a sectioned view taken along line 4 - 4 of Fig. 2.
• Fig. 5 is a sectioned view taken along line 5 - 5 of Fig. 2.
• Fig. 6 is a sectioned view taken along line 6 -6 of Fig. 2.
• Fig. 7 is a sectioned view taken along line 7 -7 of Fig. 3.
• Fig. 8 is a partial front view of an induction valve assembly according to an embodiment of the
• Fig. 9 is an isometric view of an exhaust valve assembly and a cylinder lining according to an embodiment of the invention.
• Fig. 10 is a sectioned, isometric view of a seal included in an exhaust valve assembly of an
• Fig. 11 is an enlarged detailed sectioned view of a portion of the exhaust valve assembly of the
• Fig. 1 shows a cylinder assembly 20 for an internal combustion engine.
• the cylinder assembly 20 includes a cylinder lining 22 having a major cylindrical axis 23.
• Cylinder lining 22 is comprised of two segments - - a lower lining segment 22a and an upper lining segment 22b. Cylinder lining segment 22a is accommodated in an appropriately sized hole 24 in an engine block 25.
• Cylinder lining segment 22b is discussed in greater detail hereinafter.
• Engine block 25 has mated thereover an engine head 26.
• An upper inner peripheral edge of the hole 24 is peripherally recessed for receiving an annular seal 28.
• Annular seal 28 has a top interior surface which is beveled at an angle on the order of about 45 degrees (see Fig. 11).
• Annual seal 28 has a lower lip which protrudes into hole 24 and covers the axial top of cylinder lining segment 22a.
• the cylinder lining 22 has a piston
• FIG. 1 (unillustrated in Fig. 1, but illustrated as element 21 in Figs. 2 and 3) reciprocating therein in customary fashion.
• An ignition plug 29 is threadingly received in plug channel 29A of head 26, centrally above the cylinder lining 22.
• a spark end of the plug 29 depends into an annular combustion chamber 21a provided between a squish band 21b of piston 21 (see Figs. 2 and 3).
• cylinder assembly 20 further includes an exhaust valve assembly 30.
• Exhaust valve assembly 30 includes the cylinder lining segment 22b, also known as an exhaust valve ring member.
• the exhaust valve ring member includes both a lower exhaust ring 32 and an upper exhaust ring 33. Both rings 32 and 33 are centered about axis 23.
• Lower ring 32 has inner and outer diameters substantially equal to the respective inner and outer diameters of the cylinder lining lower segment 22a.
• Upper ring segment 33 has a smaller inner diameter than the lower ring 32, thereby forming an overhanging ledge 34 which, as explained below, facilitates a sealing function.
• the upper exhaust ring segment 33 has three valve stems 40 formed (preferably soldered) on an axial end thereof. Valve stems 40 are provided at 120 degree angles about axis 23. It should be understood that fewer or more than the illustrated number of valve stems 40 can be employed in other embodiments.
• exhaust valve assembly 30 reciprocates parallel to axis 23 (up and down in Fig. 1). During an exhaust stroke, lining segment 22b is lifted above seal 28, allowing exhaust gases to escape radially through exhaust channels or manifold 42 formed in engine block 25 and head 26. During other strokes, cylinder lining segment 22b sits tightly on seal 28, blocking exhaust manifold 42.
• Fig. 11 shows in detail, among other things, the sealing of the exhaust valve assembly 30, including annular seal 28 mentioned before as fitting over the cylinder lining 22.
• Fig. 11 shows an access ring 44 and a fishtailing seal 46.
• Access ring 44 is threadingly fastened about the periphery of the cylinder head portion which is directly above the cylinder. Removal of access ring 44 faciliates engress and egress of the exhaust valve assembly 30 during fabrication and repair.
• the seal 46 shown partially in cross section in Fig. 10, has an annular shape as seen from above but an lateral teardrop shape in cross section.
• the outer peripheral edge of seal 46 has a series of small radial cuts or notches 47, which enhances its elasticity.
• Seal 46 not being under high temperature, may be fabricated from normal steel.
• seal 46 assures an airtight closure variable in height, as it is not possible to have a precise connection between the head 26 and the rest of the block 25.
• the exhaust valve assembly 30 may be seated too high and (without the benefit of seal 46) gases may escape. But with the provision of the seal 46, the vertical amplitude of the segment flexures will be higher than the amplitude of the tolerance of combining head and block.
• the exhaust valve assembly 30 is provided only along the wall of the cylinder and on the highest part of the cylinder assembly 20. In this manner, the exhaust valve assembly 30 does not interfere with the surface that concerns the piston rings.
• an exhaust area is provided with comparable area with a desirably large induction hole but without extending the exhaust area undesirably deeper into the cylinder (e.g., along the axis 23), and thereby increasing the likelihood of interfering with the piston and ring structure.
• the cylinder assembly 20 has a bore of approximately 90 mm, but the fissure created by the opening of exhaust valve assembly 30 (projected on axis 23) is only about 10 mm.
• valve assembly 30 of the present invention overcomes a great disadvantage of prior art exhaust valves.
• Prior art exhaust valves open toward the inside of a cylinder and accordingly oppose the outflow of combustion gases and further heat the valve stem.
• the exhaust valve assembly 30 of the present invention does not, when opened, protrude into the interior of the cylinder, and does not expose its valve stem to hot exhaust gases. Therefore, there is substantially less danger of preignition.
• the exhaust valve assembly 30 of the present invention is well protected in its seat over the exhaust fissure, and accordingly Is not significantly exposed to exhaust gases escaping from the cylinder assembly 20, nor does it obstruct flow of exhaust gases. Any heat that is absorbed by the exhaust valve assembly 30 is dissipated through stems 40 and its lower edge (which is near the cooling liquid). Moreover, the exhaust valve assembly 30 of the present invention permits the entire exhaust manifold 42 to be opened so that the depression therein increases the effective volumentric efficiency of the cylinder during induction.
• Prior art valving arrangements employing exhaust valves on the cylinder head permitted only limited opening of the exhaust valves in view of the proximity of the piston. However, piston proximity is not a problem for the exhaust valve assembly 30 of the present invention. Accordingly, full opening of the exhaust manifold 42 provides a total suction
• cylinder assembly 20 of the embodiment of Fig. 1 has one or more induction valves provided above lining 22 and in head 26 around plug 29.
• the number and positioning of the induction valves is not critical for an understanding of the operation of the exhaust valve assembly 30 of the present invention.
• a currently preferred embodiment having one induction valve is illustrated, for example, in Figs. 2 and 3.
• Figs. 2 - 3 and 7 illustrate an embodiment of a timing system for controlling the operation of exhaust valve assembly 30 of Fig. 1.
• Figs. 2 and 3 (as well as Fig. 8) illustrate an induction valve
• Induction valve assembly 50 includes a flat valve ring member 54 concentric about cylinder axis 23. Ring member 54 is thus also concentric with ignition plug 29. Ring member 54 has a surface area approximately equal to half the surface area of the roof of the
• the single ring member 54 provides a passage area on the order of about twice as large as a conventional arrangement employing four valves, and approximately two and one half times as much passage area as a conventional two valve arrangement.
• ring member 54 The top edges of ring member 54 are beveled for seating against annular seals 56, 58. Seal 56 is shown in Fig. 8; both seals 56 and 58 are shown in Fig. 2.
• Induction valve ring member 50 has three stems 60 extending upwardly on an axial top surface of ring 50 (e.g., extending in a direction parallel to cylindrical axis 23). Induction valve stems 60 are positioned about axis 23 at 120 degree angular intervals, and are
• the timing system of the embodiment of Figs. 2, 3 and 7 includes both an induction timing sub-system and an exhaust timing sub-system.
• Induction timing subsystem includes an induction timing gear 70; two
• induction rollers 72 and, an induction timing linkage to which the tops of the induction valve stems 60 are connected.
• Induction timing gear 70 is disk-shaped bearing (the terms “gear” and “bearing” being used
• Gear 70 lies in a plane perpendicular to cylinder axis 23.
• Gear 70 has its center on axis 23.
• Gear 70 is rotatable (via bearings or the like) about the head wall portion which forms plug channel 29A.
• Gear 70 has gear teeth 74 formed on its outer periphery.
• induction timing gear 70 On its axial underside surface 76, induction timing gear 70 has three annular surface segments, including inner surface segment 76a; outer surface segment 76b; and, intermediate surface segment 76c (see Fig. 2). Outer surface segment 76b rides on shoulders 80, which in turn rest on head support surfaces 82 (see Fig. 2). A portion of intermediate surface segment 76c forms an integral earning surface against which rollers 72 ride.
• the earning surface includes lobes 78 (see Fig. 3)
• Induction rollers 72 are provided at 180 degree intervals about cylinder axis 23. Each of the two induction rollers 72 are concentrically mounted about a roller pin 84. A proximal end of each roller pin 84 is anchored in a roller post 86. Each roller post 86 is mounted on head support surface 88.
• a guide roller 90 is mounted intermediate roller post 86 and induction roller 72.
• each roller pin 84 is engaged by a reciprocating circular collar member 94.
• Collar 94 serves as part of the induction linkage. Collar 94 reciprocates about head wall 26 in a direction parallel to cylinder axis 23, and is concentric with cylinder axis 23. At its top collar 94 has the two corresponding roller pins 84 soldered or otherwise affixed thereto.
• an underside surface of collar 94 has attached thereto, near its outer periphery, the upper ends of induction valve stems 60.
• the underside surface of collar 94 at a diameter intermediate those of the valve stems 60 and head wall 26, is fitted with a spring 100.
• Spring 100 is concentric with and extends around the portion of head wall 26 which forms plug channel 29A.
• a strength of spring 100 at rest on the order of 65 Kg. is sufficient to seal the exhaust valves. In the crossing lift existing between the exhaust valve and the suction valve, the spring 100 will never exceed the highest compression established, in which case one has to pay attention that the valves are both partially opened and the sum of the two lifts must be lower or equal to the maximum lift of each exhaust or suction valve.
• the exhaust timing sub-system includes an exhaust timing gear 110 (see Fig. 3); three exhaust rollers 112; and, an exhaust timing linkage to which tops of exhaust valve stems 40 are connected.
• Exhaust timing gear 110 is a ring-shaped bearing (the terms “gear” and “bearing” being used interchangeably for this element), and lies in a plane perpendicular to cylinder axis 23.
• Gear 110 rotates (via interior peripheral bearings or the like) on support surface 114 provided by engine head 26.
• Gear 110 has gear teeth formed on its outer periphery. At its outer periphery, the upper surface of gear 110 provides a earning surface, having earning lobes such as lobes 116 provided thereon (see Fig. 3).
• exhaust rollers 112 ride on the earning surface provided by the outer periphery of the upper surface of gear 110.
• Each of the three exhaust rollers 112 is centrally and rotatably mounted on an outer end of a roller pin 120.
• An inner end of each roller pin 120 is anchored in a plate 122.
• a lower surface of plate 122 lies in a plane perpendicular to axis 23.
• Plate 122 has its outer edges shaped to form a triangle. Plate 122 is thicker towards its center, and has a central aperture (for fitting about the portion of head wall 26 which forms the plug channel 29A) .
• plate 122 supports spring 100, and many even have the bottom of spring 100 soldered or otherwise anchored thereagainst.
• the top of plate 122 may even have an annular groove for
• each roller pin 120 carries a guide roller 126 and a clamp 128 (see Figs. 3 and 7). Clamp 128 receives the upper end of a respective one of the exhaust valve stems 40 aligned therebeneath.
• Guide rollers 126 are each confined by a pair of upstanding guide walls 127. As shown in Fig. 3, spacer guide walls have the shape of a right triangle. Guide rollers 90 for the induction rollers 70 likewise are confined by guide walls 129 (see Fig. 7).
• Fig. 3 further shows means for driving the timing system.
• the driving means includes a driving shaft assembly 150 having a driving shaft axis 152.
• Driving shaft axis 152 is parallel to cylinder axis 23 but displaced to a side thereof.
• Driving shaft assembly 150 includes three driving shaft segments, particularly lower segment 150a, middle segment 150b, and upper segment 150c. Each segment has an axial bore for receiving a center spline 153.
• Spline 153 has two helically threaded segments, particularly spline segment 153a at its bottom and segment 153b at its top.
• Driving shaft segment 150b includes a toothed gear 154 radially mounted thereon so that its peripheral teeth mesh with teeth 74 provided on induction gear 70.
• driving shaft segment 150c includes a toothed gear 156 radially mounted thereon so that its peripheral teeth mesh with teeth provided on exhaust gear 110.
• driving shaft assembly 150 has a driving shaft gear 158 which meshes with a cross shaft gear 160.
• cross shaft gear 160 also meshes with a comparable driving shaft gear 162 for another side of head 26.
• driving shaft assembly 150 includes a ball bearing 164 having an engagement or connection handle 166.
• Handle 166 is mechanically linked to an unillustrated rotating drive actuator, which in turn is governed in accordance with motor RPM and other
• the rotating drive actuator rotationally displaces the spline 153, thereby causing the spline 153 to adjust the positioning of the gears 154, 156 in accordance with all requirements.
• Adjustment of gears 154, 156 in turn performs an RPM-dependent adjustment for induction gear 70 and exhaust gear 110, respectively.
• Head 26 is also provided with oil passageways
• head 26 is provided with oil passageways 172 for the exhaust timing gear 110. These oil passageways are used only with the particular type bearing shown, but would not be used should roller bearings instead be employed.
• the timing system of the present invention comprises two gears 70, 110, both rotating about cylinder axis 23, but lying in spaced apart parallel planes (perpendicular to cylinder axis 23).
• Surfaces of the gears 70, 110 facing each other form earning surfaces operative for timing the opening and closing of valves.
• Both valve assemblies 30 and 50 move parallel, rather than at an angle to, cylinder axis 23.
• FIG. 3 illustrates portions of a timing system for an adjacent cylinder assembly, it being well understood that the cylinders are laterally aligned in conventional manner and commonly driven by intermeshed gearing.
• screws 180 are provided for securing head 26 to block 25. Screw holes 182 are also provided for a cover to attach to head 26.
• engine block 25 and engine head 26 are provided with passageways for the circulation of a coolant fluid.
• the cylinder lining 22 has a piston reciprocating therein.
• induction valve assembly 50 is to be opened during an intake stroke of the engine; that the induction valve assembly 50 and the exhaust valve assembly are both to be closed during both the compression and combustion strokes of the engine; and, that the induction valve assembly 50 is to be closed and the exhaust valve assembly 30 opened during an exhaust stroke of the engine.
• the timing of the opening and closing of the induction valve assembly 50 and the exhaust valve are both to be closed during both the compression and combustion strokes of the engine; and, that the induction valve assembly 50 is to be closed and the exhaust valve assembly 30 opened during an exhaust stroke of the engine.
• the timing of the actuation of the induction valve assembly 50 is governed by the earning surface provided in the inner surface segment 76a on the
• induction valve assembly 50 When the induction valve assembly 50 is to allow fluid communication between induction channel 52 and the interior of cylinder assembly 20
• induction rollers 72 (i.e., during an intake stroke), lobes 78 on the earning surface on inner surface segment 76a cause induction rollers 72 to descend (i.e., travel in a direction parallel to axis 23 toward the cylinder assembly 20). Descent of the induction rollers 72 pushes down the circular collar member 94, which in turn pushes down the valve stems 60 and hence the flat valve ring member 54.
• valve ring member 54 is unseated from seals 56, 58, allowing induction fluid to enter from induction channels 52 into combustion chamber 21a.
• the induction rollers 72 do not ride on the lobes, but rather on a flat portion of the inner surface segment 76a, thereby causing valve stems 60 to rise and valve ring member 54 to seat against seals 56, 58 in the manner shown in Fig. 2.
• the timing of the actuation of the exhaust valve assembly 30 is governed by the earning surface provided on the outer periphery of the topside of exhaust timing gear 110.
• exhaust rollers 112 follow the periphery of gear 110.
• the exhaust valve ring member of the present invention has a height (projected on central axis 23) which is only about 11 mm, which is less than 50% of the cylinder stroke and preferably less than 20% of the cylinder stroke.
• this new "ring-shaped" valve will have to have a surface to close equal to half the area of the cylinder roof; it will be, then, possible to widen the external diameter in such a way as to increase the surface by an amount equal to the surface of the hole for the plug, through which the mixture will then be free to enter; in this case too the contact surface between the plug edge and the valve represents a lost surface to be added to the external one, but still measuring less than the three valves. Moreover, if the space around the plug does not allow enough width to permit the passage of water around the plug itself, it will then be possible to further widen the "ring-shaped" valve (covering the same surface), as much as thought to be necessary.
• This special inlet valve so produced, creates a passage area twice as big if compared to the four valves and about two and a half times if compared to the classic two valves; the present abilities in constructing pieces of micromechanics can now reach such levels of infinitesimal tolerance as to make it possible for the two edges of the valve , the interior and the exterior one , to fit in their respective seats without mutual interferences; the seats will then consist of the usual material.
• the opening for the exhaust gases can be found only along the wall of the cylinder and on the highest part of the chamber in order not to interfere with the surface that concerns the piston rings, they have, therefore to be under the exhaust hole.
• we want to give the exhaust hole an area proportional to the induction hole we find some problems: the dimension of one or more side windows would be, indeed, notable in height, and would impose the use of a piston with rings at the base of the skirt. That would not be functional; we would have, then, problems with the sealing of the valves, as it would be necessary to open towards the outside and to drive radial valves is a mess.
• the solution is to make only one hole of limited height but which turns all around the highest part of the cylinder: in this way, we can obtain an area of passage actually equal to the induction one, with a fissure of only 11 mm, if the cylinder has the considerable bore of 100 mm.
• the rings can have, in this way, a natural position finding their spline 10 mn or even less under the top of the piston (according to the compression ratio, the shape of the chamber and the squish band).
• the hole has a special valve, obviously cylindric, (table 6) that moves up and down like a guillotine from the head to the chamber and viceversa.
• the valve will be higher than it sholud be on the upper seat, and will be no longer sealed, in the case in which the head is too lifted from the rest of the engine, we can have an escape from the lower part of the valve, that will not be able to close the whole spline, as it will have already knocked against its upper seat.
• the segment is required to make oscillations that are not very Toll and it has to bear a small mechanical effort and so, it can have a limited thickness, which, with small appropriate cuts around the external circumference, could have the required elasticity without having to apply to it weight superior to 5 Kg.
• the lower part of the valve does not. present any particular problem for airtight closure, since it may be considered as a big valve with the diameter, equal to the cylinder. Therefore a joining will be created which is similar to that one of traditional valves with an imclination of the edge of contact of 30-45 degrees to the axis of the valve.
• valves and pipe will be covered with material similar to that of traditional valve seats.
• upper point of contact of the valve on the segment will be protected.
• cams of distribution will have normal and already ested dimensions.
• the common exhaust valves have a very great disadvantage, that of opening towards the inside of the cylinder, opposing the normal outflow of the exhaust gases which after having overcome them, continue to eat the stem too. The temperatures reached, are very high in comparison to the suction-valves.
• the guillotine valve is well protected in its seat over the exhaust fissure. It is, therefore, not exposed to exhaust gases and it does not obstruct their flow. Any heat that it. could absorb, when it is closed, would be easily absorbed by the stems and the lower edge that is near the cooling liquid, as happens with the piston.
• the task of sending exhaust gases towards the two sides of the block and then to their respective exhaust manifolds is left to the separating walls (strong and well-cooled) between the cylinders. In this way the entry and exit of gas is facilitated.
• the upper supporting base of the spring On the top of the three stems of the intake valve, we fix the upper supporting base of the spring, better still if counter balanced and of considerable dimensions, inside which there is an alluminium cylinder where the plug can be inserted.
• the spring is inside the three stems and has as lower supporting base, a small bowl of appropriate shape which lies on the head; the opening of the valve occurs when the upper supporting base is pushed down.
• roller tappets on which the low of lifting is imposed by means of the rotation of a thrust ball bearing, belonging to the head cover and that presents (on its lower side and directly in contact with the rollers) two backs which, during every revolution, push the tappets with proper acceleration and deceleration.
• the backs are nothing else but the eccentrics of normal cams flat developed on the plane of the lower part of the bearing that is dented externally and that receives movement from the driving shaft through gearings. In the same way, it is engaged with the teeth of the bearings of the intake valves of chambers which might, possibly be contiguous. For dimension and rotation speed (equal to half a turn of the driving shaft) of the bearing, the development, of a very long cam is possible. A glass inside the spring which runs outside the cylinder containing the plug, will prevent undesiderable oscillations of the stems of the valve. In the same way, the exhaust valve is controlled by three backs of a bearing which lies on the head and encloses the stems of the valve externally.
• rollers axe fixed with a foot on the stems of "the guillotine" when the backs operate on rollers (and they act simultaneously), moving them up, the whole valve is lifted, it opens in this way the exhaust circular fissure; the three stems fixed on the edge of the valve push down the valve, instead, when it is necessary for it to be closed. This happens because the three stems belong to the small lower supporting bowl of the spring of the intake valve which, being partially at rest, during the exhaust phase, can be used even for the exhaust valve.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Geometry (AREA)
• Valve-Gear Or Valve Arrangements (AREA)
• Valve Device For Special Equipments (AREA)

Priority Applications (7)

Applications Claiming Priority (2)

Publications (1)

Family

ID=11335451

Family Applications (1)

Country Status (9)

Cited By (1)

Citations (11)

Family Cites Families (3)

• 1992
  • 1992-07-27 IT ITBA920023A patent/IT1263277B/it active IP Right Grant
• 1993
  • 1993-07-27 JP JP6504724A patent/JPH08501612A/ja active Pending
  • 1993-07-27 CA CA002141187A patent/CA2141187C/en not_active Expired - Fee Related
  • 1993-07-27 BR BR9306805A patent/BR9306805A/pt not_active IP Right Cessation
  • 1993-07-27 ES ES93919830T patent/ES2141772T3/es not_active Expired - Lifetime
  • 1993-07-27 DE DE69327104T patent/DE69327104T2/de not_active Expired - Fee Related
  • 1993-07-27 EP EP93919830A patent/EP0653015B1/de not_active Expired - Lifetime
  • 1993-07-27 AU AU49933/93A patent/AU4993393A/en not_active Abandoned
  • 1993-07-27 WO PCT/US1993/006952 patent/WO1994002717A1/en active IP Right Grant

Patent Citations (11)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events