Figures 1 through 4 Illustrated two example couplings of the present invention are used as substitutes for carden shaft members 3 linked couplings 1 and 2.
 Each coupling 1 and 2 includes an inner ring member 111, an intermediate ring member 121 and an outer ring member 131. The center of the internal member 111 is located on the center axis X. The internal member 111 has an external convex spherical surface 112, the convex spherical surface is a convex spherical surface, the center of which is located at point C on the central axis X.
 The inner ring member 111 has a central porosity 100 to receive the shaft member 3. The central pore 100 has a keyway 101, the keyway is joined by the corresponding key 102 on the shaft member 3. Alternatively, the end of the shaft member 3 may have key teeth to engage the corresponding key teeth around the central pore.
 The intermediate annular member 121 has an internal concave spherical surface 123, the concave spherical surface is a spherical segment complementary to the external convex spherical surface 112 of the internal member 111. The center of the concave surface 123 is also located at point C. Axis 114 with opposite diameter extends radially along axis X along the second axis Y orthogonal to axis X, and the second axis Y passes through point C.
 Axis 114 through the internal member 111 extends into the intermediate member and the member 111 is coupled to the intermediate ring member 121. Axis 114 so that the middle toroid member 121 is constrained to rotate around the second axis Y with respect to the internal member 111.
 The intermediate ring member 121 has an outer periphery 122, the outer perimeter is a convex sphere, the center of which is located at point C. The outer ring member 131 has an inconcave spherical surface 133 complementary to the outer convex surface 122 of the outer convex surface of the intermediate member 121, the concave spherical surface is a convex spherical surface and the center is located at point C. A pair of axes 134 with opposite diameters extend radially from the central axis X on the third axis Z, and the third axis Z is orthogonal to axis Y and axis X. The shaft 134 with opposite diameter is connected to the intermediate ring member 121 to the outer ring member 131. The third axis Z crosses the same center point C as the center axis X and the second axis Y.
 Axis 134 such that the middle ring member 121 and the outer ring member 131 is constrained to one relative to the other rotation around the axis Z. Axis 134 allows the relative rotation of the intermediate ring member 121 and the outer ring member 131 independent of the relative rotation of the internal member 111 and the intermediate ring member 121.
 Shaft 114 is supported in the pin roller bearing 125 mounted in the end of the hole 124 mounted in the intermediate member 121 and fixed in the hole 115 in the internal member 111.
 Shaft 134 is fixed in the hole 137 of the outer ring member 131 and is supported in the end of the needle roller bearing 129, the needle roller bearing is fixed in the middle toroidal member 121 in the hole 128.
 The thickness of the members 111, 121 and 131 is selected so that the convex outer periphery 112 and the concave periphery 123 of the inner member 111 and the concave member 121 leaves a small gap 103; and similarly, a small gap 103 is correspondingly left between the convex outer periphery 122 and the concave periphery 133 of the intermediate toroidal member 121 and the concave inner periphery 133. Thus, the inner and outer surfaces of the member do not touch each other. However, in the event of a failure, the internal and intermediate ring members are retained in the structure of coupling 1.
 Loading slot 104 (marked on Figure 2 medium) is provided to allow the internal member 111 inserted into the intermediate ring member 121 and the intermediate ring member 121 is inserted into the outer ring member 131.
 The ended needle roller bearings 125 and 129 have an elastic retaining ring 167, the elastic retaining ring is assembled around the perimeter of the needle roller bearing near its closed end, thereby engaging with the corresponding groove 168 in the surface of the orifices 124 and 128. The elastic retaining ring 167 is used to keep the bearings 125 and 129 resistant to the centrifugal forces generated when the coupling 1 rotates at high speeds. Seal 169 is positioned into a gap between the bridge bearings 125 and 129 and the shafts 114 and 134 to prevent contaminants from entering the bearing and lubricant flowing out of the bearing.
 Axis 134 has a flange 140 each at its outer end. The flange 140 is installed in the seat 141 in the outer surface of the outer toroidal member 131. The elastic retaining ring 142 is mated to the flange 140 and the inner peripheral hole 137 to hold the shaft 134 firmly in place.
 Coupling 1 of the outer ring member 131 has a bolt orifice, wherein through the transmission or driven shaft member 7 end flange 6 bolt 5 is coupled to the outer ring member 131.
 at Figures 1 through 5 In the configuration shown, the outer ring member 131 of the coupling 2 also has a bolt orifice, wherein the bolt 5 through the end flange 6 of the second drive or driven shaft member 8 is coupled to the outer ring member 131 of the second coupling 2.
 As an alternative, instead of one of the internal members of the coupling is a toroidal member, the internal member may be formed as a convex member having a boss, wherein the shaft member 3 extends from the boss to the center of the other coupling in the pore.
 As another alternative, the shafts 114 and 134 are supported in the bearings of the inner member 111 and the external member 131, respectively, instead of the intermediate member 121.
 at Figures 1 through 5 In, the coupling of the present invention is shown as one of the two couplings connected by a common shaft member in lieu of the Carden coupling. However, a coupling such as shown as 1 or 2 may be used alone, wherein one of the shafts 3 and 7 is a transmission shaft and the other is a driven shaft. As an alternative, instead of bolting the shaft, other ring members can be connected to another rotatable device.
 When two couplings 1 and 2 such as Figure 1 When connected by shaft member 3, the rotation speed of one of the transmission or driven shafts 7 and 8 will be the same as the rotation speed of the other in shaft members 7 and 8, regardless of what misalignment is between shaft members 7 and 8.
 at Figure 5 In, the double concentric joint 20 is composed of two couplings 21 and 22 each combined with the present invention, a coupling is mounted inside another coupling, the outer ring member of the inner coupling 21 is an internal member of the external coupling 22 and is referred to hereinafter referred to as a common member 231. Couplings 21 and 22 have a common center C.
 Coupling 21 includes: an internal member 211, the member is annular in this example, having a central hole 200 having a key tooth 201 around the hole to receive a transmission or follower shaft with key teeth (not shown); the outer ring member - i.e., a common ring member 231; and an intermediate member 221.
 Coupling 22 includes an inner ring member – i.e., a common ring member 231, an intermediate member 241 and an outer ring member 251.
 In this example, the internal member 211 is a ring, the intermediate member 221, 241 and the common ring member 231 includes a spherical segment. Each member of the member (211, 221, 231, 241, 251) is set around the common central axis X and has a common center C on the common axis X.
 The outer ring member 251 has a bolt orifice on its side to receive the bolt, the bolt passes through the end flange of the shaft member (not shown) to connect to the outer ring member.
 The inner member having an external convex spherical periphery 212, and the intermediate annular member 221 of the coupling 21 has an inner concave spherical periphery 223, the convex periphery of the inner member 211 is accepted in the concave spherical periphery.
 The intermediate toroidal member 221 has an outer convex spherical periphery 222, and the common annular member 231 has an inner concave spherical periphery 233, the outer convex periphery of the intermediate annular member 221 is accepted in the concave spherical periphery.
 Common annular member 231 has an external convex spherical periphery 232, and the intermediate toroidal member 241 of the coupling 22 has an inner concave spherical periphery 243, the common annular member 231 of the convex periphery 232 is accepted in the concave spherical periphery.
 The intermediate annular member 241 of the second coupling 22 has an external convex spherical periphery 242, and the outer annular member 251 has an inner concave spherical periphery 253, the outer convex periphery of the intermediate annular member 241 is accepted in the concave spherical periphery.
 The outer convex periphery (212, 222, 232, 242) and the concave periphery (223, 233, 243, 253) are concentric and complementary to the center C.
 A pair of shafts with opposite diameters 214 extends from the relative hole 215 in the internal member 211 to the bearing 225 fixed in the hole 224 in the intermediate toroidal member 221. Axis Y of axis 214 is perpendicular to the common central axis X. The intermediate toroidal member 221 of the coupling 21 is constrained to rotate around the second axis Y perpendicular to the common axis X around the internal member 211.
 A pair of shafts 234 with opposite diameters (the common axis Z perpendicular to the common central axis X and the second axis Y both) are fixed in the common ring member 231 of the opposite hole 236 and mounted in the bearings 227 and 247, the bearing is fixed in the middle ring member 221 of the coupling 21 hole 226 and the middle toroid member 246 of the coupling 222 in the hole 241. The common annular member 231 is thus constrained to rotate around the middle toroidal member 221 and the intermediate toroidal member 241 perpendicular to the third axis Z perpendicular to the common axis X and the second axis Y.
 A pair of shafts 254 with opposite diameters extends from the relative hole 255 in the outer ring member 251 to the bearing 245 fixed in the hole 244 in the middle fourth ring member 241. The axis of axis 254 is consistent with the second axis Y perpendicular to the common central axis X. The outer ring member 251 is thus constrained to rotate around the second axis Y perpendicular to the common axis X around the intermediate ring member 241.
 Bearings 225, 245, 227 and 247 may be plain bearings or pin roller bearings with sealed ends.
 The dimensions of the members 211, 221, 231, 241 and 251 and the shafts 214, 234 and 254 are selected to provide a small gap between the outer periphery of each convex surface and the inner periphery of each concave surface 203. The gap between the members 203 and the concentricity of the member is maintained by the ends of the shafts 214 and 254, the ends are correspondingly fixed in the holes 215 and 255 of the internal member 211 and the outer member 251 by an interference fit and are supported by the bearings 225 and 245 in the intermediate toroidal members 221 and 241, and are also maintained by the shaft 234, the shaft is fixed in the hole 236 of the common toroidal member 234, This is fixed by forming an interference fit in the hole and at either end of the shaft by bearings 227 and 247 in the intermediate members 221 and 241. Shafts and bearings can also be maintained by elastic retaining rings, snap rings, pins or bolted glands.
 Members 211, 221, 231 and 241 are then loaded within members 221, 231, 241 and 251 by inserting in a direction parallel to the common central axis, and then rotating the smaller member to an appropriate position. After that, put the shaft in place.
 The common ring member 231 transmits the rotational motion and torque from one coupling 21 to another coupling 22, or vice versa.
 Figure 5 The coupling is a concave coupling, because any connecting shaft member is inserted into the central pore 200 by connecting to the key tooth 201. By replacing the anroidal member 211 with a boss, the shaft member extends laterally from the boss to the ground, and the input or output end is connected externally.
 In all instances, the appropriate width of the clearance 103 and 203 in all instances is a design issue for the intended application, varying according to the intended use of the coupling, rotational speed, load distribution and material used in the toroidal member. However, in general, the clearance 103 or 203 will be 0.5% of the total diameter in the case of the coupling with a total diameter of less than 100mm, and 1% of the total diameter for a coupling with a diameter of 100mm or greater.
 In an example, ideally, the farther the member is from the center axis X, the less inertia mass the member has. This can be achieved by selecting a material, adding orifices to the intermediate and external components as needed, and / or making the intermediate members thinner than the internal members and thus making the external members thinner than the intermediate members. This ensures that the inertial mass of the intermediate and external components is reduced compared to the inertial mass that all components with the same material would otherwise have.
 With the distance from the center axis X and reduce the inertia mass of the rotating portion of additional measures comprising the axis 134 and 234 having a smaller diameter than the axis 114 and 214, and the axis 254 having a smaller diameter than the shaft 234.
 The coupling described above may be made of any suitable material, but the following wishes should be taken into account in the design: the inertia mass of the member is reduced as the distance from the central axis X increases.
 If a terminated plain bearing is used, the surface may have a metal, such as high-performance steel, brass, bronze, aluminum, titanium, etc., or having plastics such as nylon, glass-filled nylon, acetal, ABS,
 Metal ring members can be lubricated with conventional lubricants such as greases. Alternatively, a dry film lubricant surface may be used, such as a plastic bushing. The choice of material and lubricant depends on the intended use of the coupling.
 at Figures 1 through 5 , as described, the outer periphery of members 111 and 121 and members 211, 221, 231 and 241 is a convex spherical periphery, and the inner periphery of members 121 and 131 and 221, 231, 241 and 251 is a concave spherical periphery. Since the contact between the members may be avoided by maintaining a gap between the members 203 via the shaft, and if the gap is large enough, the periphery surface may be cylindrical; alternatively, the periphery may be chamfered towards its edge. The shafts 114 and 134 and 214, 234 and 254 maintain the concentricity of the members of the coupling are also maintained.
 Figures 1 through 5 The coupling can be provided such as Figures 6 through 10 The pulse damper shown.
 Pulse damper 301 having: a first disc end plate 305, the first disc end plate may be connected to a rotatable input transmission; and a second disc end plate 306, the second disc end plate parallel to the first end plate 305 and opposite the first end plate, both end plates are set around the center axis X.
 The first end plate 305 has a shaft 352, the shaft using a flange 357 and a bolt 358 to attach to the first end plate. Axis 352 with the central axis X coaxial and extends from the first end plate 305 towards the second end plate 306.
 The second end plate 306 has a pipe fitting 362, the pipe fitting extends from the second end plate around the axis 352 coaxially and forms a housing for a pair of bearings 342 between the pipe fittings 362 and the shaft 352. The fittings 362 are stepped, thus allowing the placement of the bearing 342. Bearing 342 at one end of the fitting 362 is maintained in place by a ring lock nut 355, the ring lock nut having an internal thread 356, the internal thread is mated to the external thread 354 around the shaft 352. The open locking washer 360 is placed between the lock nut 355 and the paired bearing 342. At the other end of the fitting 362, the bearing is maintained in place through a stepped portion of the shaft 352.
 The damping ring 303 is set around the fitting 362. at Figure 7 and Figure 10 The damping ring 303 is shown in more detail. The damping ring 303 includes an even number (in this case six) wedge blocks 334 and 336, thereby forming a divider around the pipe fittings 362 are equidistantly disposed of between the elastomer members 332. Blocks 334 and 336 are separated from each other by elastomer member 332. The alternating block 336 is bolted to the first end plate 305 by bolting 307. at Figures 6 through 9 In an embodiment, blocks 334 and 336 are wedge-shaped, accompanied by slightly curved sidewalls.
 Between the block 336 is bolted to the first end plate 305 of the block 334 using bolt 308 bolted to the coaxial fitting 362 (see Figure 7 )。 Bolt 308 through block 334 such that the elastomer member 332 is supported on the coaxial fitting 362. This arrangement forces the damping ring 303 to deflect only around the central axis, not in the radial direction, thereby preventing imbalance. As can be seen in Figures 6 through 9 , the wedge block 334 has a curved side adjacent to the elastic member, the curvature of the side is increased towards the axial pipe fitting. This arrangement applies more pressure to the elastic member towards the edge of the elastic member, thus ensuring good contact with the axial fittings.
 The compliance of the damping ring 303 of the connected elastomer segment 332 absorbs power pulses delivered from, for example, an internal combustion engine by continuously and alternately compressing the fixing blocks 334 and 336 and stretching between the fixing blocks during operation. Damping ring 3 is an overmolded component, wherein the fixing blocks 334 and 336 are confined to the appropriate position by a connected molded elastomer material, the overmolding also prevents the overextension of the elastomer material along the radial direction during use.
 Pin 359 will block 334 with respect to the coaxial fitting 362 positioning and maintained in place. Further, pin 359 will block 336 with respect to the first end plate 305 positioning and assist in maintaining in place.
 For lightness, the wedge block 332 is typically made of aluminum or aluminum alloy to minimize inertial forces in the flexible coupling.
 In the illustration, the second end plate 306 is machined to Figures 1 through 4 The external member of one of the couplings shown in 131 is integral flange, but the second end plate may likewise be bolted well Figures 1 through 4 The external member of the coupling 2 shown 131 or Figure 5 The external member of the coupling 351. If the diameter of the damped part is small enough, the damped part can also be bolted Figures 1 through 4 The couplings shown 1 and 3 are internal members 111 or Figure 5 One of the internal components 211.