MXPA98001446A - Modular combination of steering wheel and bag - Google Patents

Abstract

The present invention relates to a modular combination of steering wheel and air bag comprising: a steering wheel armature including a top flange portion, a plug plate, and a structure for securing the armature to the plug plate; of air bag secured to said plug plate, said plug plate having a structure to ensure the combination to an arrow of the steering column, after the plug plate, the armature and the air bag assembly have been connected together as a subassembly, the structure for fixing the armature to the plug plate includes a plurality of rays extending from the upper portion of the flange at separate points, each having a threaded fixing hole at an opposite end of the spoke , and the plug plate includes a plurality of holes corresponding to the threaded fixing holes, and a plurality of screws or bolts passing through the holes. Either the plug plates are received or screwed into the threaded fastening holes, and one of the opposite ends of the spokes and the plug plate includes a seat surface and the other includes plugs adjacent to the corresponding holes, each button it has a generally tapered cross section where the buttons are received on the seat surface such that the outer surface of the buttons form a wedge closure with the inner surface of the seat surfaces.

Description

"MODULAR COMBINATION OF STEERING WHEEL AND AIR BAG" BACKGROUND OF THE INVENTION The present invention relates to a combination of steering wheel and air bag. The combination comprises a steering wheel armature and a separate plug plate having a structure for attaching to an arrow of the steering tube. The invention also relates to a method for forming a modular combination of steering wheel and air bag and a method of assembling a modular combination of steering wheel and air bag. -Before the introduction of the airbags, the flywheel assemblies could easily be fixed to an arrow of the steering tube. The access to the arrow of the tube through a steering wheel assembly was carried out through the plug of the steering wheel assembly from a front face of the steering wheel assembly. The airbag assemblies for a vehicle driver are typically located in the plug of the steering wheel assembly. In this way, access to the arrow of the steering tube through the plug of the steering wheel assembly has become more difficult. Current methods for attaching a steering wheel and airbag assembly to an arrow in the steering tube require a two-step process. A steering wheel assembly is initially fixed to an arrow of the steering tube. An air bag assembly is then attached to the steering wheel assembly. This two-step, two-component assembly of the flywheel and airbag assemblies requires a large amount of time and has increased labor costs. In addition, automobile manufacturers typically obtain steering wheel assemblies and airbag assemblies from separate suppliers. Due to the assembly of two steps, the airbag and the steering wheel have separate covers. The colors and textures of the two covers must be matched to ensure customer satisfaction. Even so, it has proven difficult to match colors exactly. Another major problem with the current steering wheel and air bag assemblies is the theft of air bag assemblies. Because airbag assemblies are very expensive and can be easily removed from a vehicle, the theft of airbag assemblies has been dramatically sparked. The prior art has made several attempts to focus on these problems but this has been unsatisfactory.

COMPENDIUM OF THE INVENTION The modular combination of steering wheel and airbag of the present invention includes a steering wheel armature and a separate plug plate. The separate plug plate provides a unique way to assemble the combination of the steering wheel and the airbag. An air bag assembly is attached to a plug plate to form a sub-assembly of the plug plate. The subplate of the plug plate is then fixed to a steering wheel assembly including the steering wheel armature. A structure to ensure the combination of the steering wheel and the airbag is accessible from a rear face of the combination. The combination is then placed over the arrow of the steering tube and then secured to the arrow of the steering tube. One aspect of the present invention includes a steering wheel armature that includes an upper flange portion and a structure for attaching the upper flange portion to the plug plate. Preferably, the upper flange portion is essentially circular. The structure may include a plurality of spokes or ribs extending from the upper flange portion, the armature of the flywheel. The pins fix the plug plate to the armature. In one embodiment, a wedge closure is formed between the armature of the flywheel and the plug plate. The rays include a settling surface at the opposite end of each ray and the plug plate includes a plurality of tapered buttons that are forced towards the seating surfaces. When the bolts secure the plug plate on the opposite ends of the spokes, a wedge closure is formed between the buttons and the seating surfaces. The wedge closure is strong enough so that the bolts become unnecessary to retain the fixation after the bolts are originally driven. The armature of the flywheel preferably also includes a lower ring portion connecting the opposite ends of the spokes. The ring provides structural integrity and support to the steering wheel frame. In one embodiment, the plug plate conforms to the size of the ring portion. A plurality of fingers or pins are placed adjacent the side edges of the plug plate. A plurality of perforations are placed on the lateral edges of the ring portion. The inner and outer air bag covers of the air bag assembly include interlacing tabs each having a hole. The tabs are placed between the ring portion and the plug plate. The fingers pass through the holes and end in the perforations in the ring portion. This provides a holding feature for keeping the inner and outer air bag covers of the air bag assembly essentially within the combination during activation of the air bag component, for example, during a crash. Another aspect of the invention includes an air bag retention ring that facilitates the assembly of the steering wheel and air bag combination. In a sub-plate assembly of the plug, an air bag inflator is placed on the plug plate. A cover of the air bag is placed above the inflator of the air bag. During activation of the airbag inflator, a significant gas pressure inflation force is exerted on the airbag envelope. A retaining ring is provided as part of the envelope of the air bag that is placed around an inflator base of the air bag. The ring is fixed to the plug plate with a plurality of fasteners. In a preferred embodiment, an edge extends from the base of the inflator and is placed between the plug plate and the retainer ring. The structure of the plug plate is brought to the optimum to take advantage of the retaining ring structure. The combination of steering wheel and air bag also includes a fixing structure to ensure the combination in an arrow of the steering tube. The structure is accessible from a rear face of the remote combination of an external coating facing the driver of a vehicle, preferably from an angle perpendicular to the axis of the arrow of the steering tube. The fastening structure can include a worm gear and a complementary gear. The preferential fixation structure provides primary, secondary and tertiary retention characteristics. In one embodiment, the complementary gear is a helical gear having a gear portion, with angled teeth and a threaded shaft extending from the face of the gear portion. The worm gear is adapted to drive the worm gear to ensure the combination of the arrow of the steering tube, thereby providing a primary holding characteristic. Typically, worm gears with gears having curved teeth are used. In those combinations, the gear may not move axially relative to the worm gear. With the helical gear, some relative axial movement is possible. To remove or remove the flywheel, the worm gear can be inverted to draw the helical gear axially away from the steering tube. The helical gear helps to force the plug plate away from the arrow of the steering tube crashing into the back of the inflator This helps to break the "wedge closure" between the plug plate and the arrow of the steering tube which will be described below. The friction and gear ratios between the worm gear and the worm gear provide a secondary retention feature that prevents the combination from disengaging from the arrow of the steering tube. The fixation structure may also include a collar extending from a rear face of the combination, placed around the threaded arrow that protrudes from the back face. The arrow on the steering tube includes a threaded bore and a tapered outer surface. The threaded hole receives the threaded shaft of the helical gear. An internal surface of the collar engages the tapered outer surface of the arrow of the steering tube. The internal diameter of the collar is less than the maximum width of the arrow of the tapered steering tube. Therefore, since the combination is secured in the arrow of the steering tube, a wedge closure is created between the collar and the arrow of the steering tube, thereby providing a tertiary holding characteristic. This tertiary retention feature provides the safest attachment between the combination and the arrow of the steering tube of the primary, secondary and tertiary holding characteristics. Alternative embodiments of the structure for securing the combination in an arrow of the steering tube include a collar having a threaded inner surface, wherein the arrow of the steering tube includes a threaded outer surface. Another alternative embodiment includes a collar extending from the opposite face of the plug plate and with a tooth placed on an inner surface of the collar, wherein the arrow of the steering tube includes a circumferential spiral groove. In any mode, the combination is secured in an arrow of the steering tube by placing the combination above an arrow of the steering tube and rotating the combination to a predetermined stop position. A clamping bolt is then inserted into the threaded bore essentially perpendicular to the collar. A method for forming a modular combination of steering wheel and airbag is also disclosed. A steering wheel armor is provided. An outer air bag cover can be placed in a central area adjacent to the steering wheel frame. An external urethane coating R.I.M. it is placed around the upper flange portion and spokes of the steering wheel armature and a reinforcement / substrate of the outer cover of the airbag. In an alternative embodiment, an outer resin coating and the inner cover of the air bag are simultaneously molded into an injection mold using a compatible resin. A subset of the plug plate is also assembled including a worm gear and a worm gear, the airbag inflator, the airbag envelope and the inner cover of the airbag. The plug plate assembly is placed inside the outer cover of the air bag and secured to the ring portion of the steering wheel frame. The combined plug and flywheel plate are then fixed to the vehicle. These and other features of the present invention will be better understood from the following specification and drawings, of which the following is a brief description.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of a modular combination of steering wheel and air bag in accordance with the present invention, prior to fastening in a tube to the steering of a vehicle; Figure 2 is a detailed perspective view of a modular combination of steering wheel and air bag in accordance with the present invention; Figure 3 is a partial perspective detailed view of a modular combination of steering wheel and air bag showing a retention feature for the air bag covers; Figure 4 is a partial cross-sectional view of a modular combination of steering wheel and air bag; Figure 5 is a perspective view of a structure for connecting a combination of steering wheel and air bag with an arrow of the steering tube; Figure 6A is a transverse sectional view of Figure 5 showing a structure for connecting a steering wheel and air bag combination with an arrow of the steering tube; Figure 6B is a cross-sectional view showing the details of the structure that fix a steering wheel armature to a plug plate as shown in Figure 6A; Figure 6C is a perspective view of an alternative structure for connecting a combination of steering wheel and air bag with an arrow of the steering tube; Figure 7 is a perspective view of an alternative structure for connecting a combination of steering wheel and airbag with an arrow of the steering tube; Figure 8 is a side elevational view of the structure shown in Figure 7; Figure 9A is a partial cross-sectional view of the combination of steering wheel and air bag in accordance with the present invention; Figure 9B is a partial cross-sectional view of a sub-assembly of air bag of a combination of steering wheel and air bag of the present invention; Figure 10 is a partial cross-sectional view of an alternative structure for connecting a combination of steering wheel and air bag with an arrow of the steering tube along the lines 10--10 in the Figure 9A; Figure 11 is a partially schematic drawing of a method for forming a steering wheel assembly; Figure 12 is a partially schematic drawing of an alternative method for forming a steering wheel assembly; Figure 13 shows a method for forming a sub-assembly of the plug plate; Figure 14 shows an assembly of a steering wheel and airbag combination; and Figure 15 shows a method for securing a combination of the steering wheel and airbag in an arrow of the steering tube.

DETAILED DESCRIPTION OF A PREFERRED MODE OF THE INVENTION As shown in Figure 1, the modular combination of steering wheel and airbag 20 of the present invention is mounted on a pipe 22 of the steering of a vehicle 24. As with all steering wheels, including steering wheels of the prior art. discussed above, the combination 20 of the steering wheel and air bag rotates clockwise and counter-clockwise to control the direction of the vehicle 24 during operation. The combination 20 of the steering wheel and air bag includes an air bag assembly 26 that is activated during the collision of the vehicle 24. Unlike the previous steering gear assemblies, the combination 20 of the steering wheel and air bag are secured in the tube. 22 of the steering from a rear portion 28 of the combination 20 of steering wheel and air bag. This provides a smooth, aesthetically pleasing, front surface 29 facing the driver of a vehicle. The unitary design of the steering wheel and air bag combination of the present invention also reduces the number of steps required to secure the steering wheel and airbag to a steering tube of a vehicle, which will be discussed in greater detail at continuation. As shown in Figure 2, the modular combination of steering wheel and air bag of the present invention comprises several individual components each of which will be discussed in detail below. The steering wheel and airbag combination of the present invention includes a steering wheel frame 30. The armature 30 of the steering wheel is made of known materials, but is preferably made of cast aluminum and / or magnesium on a matrix as is known in the art. The armature 30 includes a portion 32 of essentially circular top flange and a plurality of ribs or spokes or arms (hereinafter called "spokes") 34 that are four in number. The spokes 34 extend from the separate points of the upper flange portion 32. Depending on the specific flywheel design, the combination 20 preferably includes two to four beams. The spokes 34 may comprise, in the alternative, plates extending from the upper flange portion 32. These plates can be fused or welded to the upper flange portion 32 and can be significantly wider than the spokes 34 shown in Figure 2. The spokes 34 provide a structure for connecting the upper flange portion 32 to a separate plug plate, which will be described in further detail below. At an opposite end of each beam 34, remote from the upper flange portion 32, are the threaded holes 38 that screw bolts 40 receive in a fully assembled flywheel and air bag combination. The portion 32 of the upper flange is usually referred to as the rim of the steering wheel. The armature 30 of the flywheel also includes a lower ring portion 36 connecting the opposite ends of the spokes 34. The lower ring portion 36 provides structural integrity and support to the armature 30 of the flywheel. The ring portion 36 also maintains the spokes 34 at fixed points relative to the upper flange portion 32 and one relative to the other. A plastic resin cover is preferably molded over the armature 30 of the flywheel. The lower ring portion 36 retains the spokes 34 in a desired position during this molding process. A plurality of perforations 70 are formed along the lateral edges of the ring portion 31. Each perforation receives a free end of a finger 66 formed in the plug plate 60 which will be described below. As shown in Figure 2, the lower ring portion 36 has a rectangular configuration. The lower ring portion 36, however, can have any desired configuration, including circular, triangular or elliptical, to accommodate a specific steering wheel design. The modular combination of steering wheel and air bag also includes an air bag assembly 42. The air bag assembly 42 includes an outer air bag cover 44, a horn switch 46, an inner air bag cover 48, an air bag component 50, and an air bag inflator 52. The outer cover 44 of the air bag accommodates the other components of the air bag assembly and, as shown in Figure 2, has a pair of spaced side walls 47, generally parallel, a second pair of side walls 49 , generally parallel spaced apart and an upper wall 51 connecting the upper lateral edges of the walls 47 and 49. As shown in Figure 2, the walls 47 may have recesses or may be removed particularly when no tabs are included in these walls. The walls 47 are generally perpendicular to the walls 49, the walls 49 include a plurality of tabs 53 that extend from a side edge adjacent to the base of the outer cover 44, remote from the wall 51. In the assembled form, the ring portion 36 of the armature 30 of the steering wheel is positioned around the base and the outer cover 44 of the air bag adjacent the tabs 53. The walls 47 and 49 extend from the ring portion 36 to the portion 32 of top flange of the steering wheel frame 30. The horn switch 46 is of the type known in the art and controls the horn function of a vehicle. In a modality, the horn switch 46 activates a horn of the vehicle when a vehicle operator presses the external surface 29 and therefore, the horn switch 46. The horn switch 46 is positioned between the walls 51 and 58 of the covers 44 and 48 of the outer and inner covers of the air bag, respectively. Because the horn of the vehicle is activated by depressing the horn switch 46, the inner cover 48 of the air bag must provide some resistance against the horn switch 46 during a pushing force of the operator. In this way, the inner cover 48 of the air bag is made of a more rigid, less resilient resin material. As with the outer cover 44 of the air bag, the inner cover 48 of the air bag must accommodate certain components of the air bag assembly 42, including an air bag cover 50 and an inflator 52. In the embodiment shown in Figure 2, the inner cover 48 of the air bag includes a pair of generally parallel spaced apart walls 54 and a second pair of spaced, generally parallel walls 56. As shown in Figure 2, the walls 54 may have recesses, particularly when no tabs are included in these walls. The walls 56 are essentially perpendicular to the walls 54. The inner cover 48 of the air bag also includes an upper wall 58 connecting the upper lateral edges of the walls 54 and 56. The horn switch 46 is above the surface external of the upper wall 58. The walls 56 include a plurality of tabs 55 that extend from the opposite lateral edges of the walls 56 remote from the upper wall 58 of the inner cover 48 of the air bag. The inner cover 48 of the air bag fits within the outer cover 44 of the air bag with the switch 46 of the horn sandwiched between the walls 51 and 58. The walls 56 of the inner cover 48 of the air bag are adjacent to the walls 49 of the outer cover 44 of the air bag. Also, the walls 54 of the inner cover 48 of the air bag are adjacent to the walls 47 of the outer cover 44 of the air bag. Component 50 of the air bag and inflator 52 are of the type well known in the art and can be obtained commercially from air bag manufacturers, including TRW and Morton International. During a collision of the vehicle 24, the inflator 52 of the air bag is activated and inflates the envelope 51 of the air bag. A gas fills the envelope 51 of the air bag by expanding the air bag outwardly away from the ring portion 36 toward the driver of the vehicle 24. The casing 51 of the inflated airbag provides a smooth surface for the driver of an air bag. vehicle to impact during a collision and distribute the load of occupants towards the structure of the steering wheel. This aspect of the steering wheel and airbag combination is well known in the art and does not form any portion of the present invention. The modular combination of steering wheel and air bag of the present invention also includes a plug plate 60. The plate 60 of the plug is generally formed in the size of the ring portion 36 and includes a plurality of holes 62 positioned at separate points adjacent the periphery of the plug plate 60. The plate 60 of the plug is fixed to the ring portion 36 and the opposite ends of the spokes 34. The holes 62 correspond to the threaded holes 38 at the opposite ends of the spokes 34. The bolts 40 pass through the holes 62 corresponding and in this way they are received screwed into the threaded holes 38 and to the armature 30 of the steering wheel. The plate 60 of the plug also includes a structure 64 for securing the combination 20 of the flywheel and air bag to an arrow 22 of the steering tube, described in detail below. The plate 60 of the plug also includes a plurality of fingers or pins 66 adjacent to the opposite side edges of the plug plate, corresponding to the number of tongues of the outer cover 44 of the air bag and the inner cover 48 of the air bag. The fingers or pins 66 terminate in the perforations 70 of the ring portion 36. The plate 60 of the plug further includes a plurality of holes 63 which receive the fasteners 61 for securing the component 50 of the air bag to the plug plate 60, which will be described in greater detail below.

As shown in Figure 3, the tabs 53 and 55 of the outer and inner covers 44 and 48 of the air bag, respectively, are retained between the plug plate 60 and the lower ring portion 36 of the steering wheel frame 30. . During activation of the air bag mechanism, inflator 52 of the air bag inflates the envelope 51 of the air bag to a maximum size. The envelope 51 of the air bag bursts through the inner cover 48 of the air bag, the switch 46 of the horn and the outer cover 44 of the air bag towards the driver of the vehicle 24. Without a certain method to retain the inner and outer covers 48 and 44 of the air bag within the airbag assembly 42, the parts of the inner cover 48 of the airbag and of the outer cover 44 of the airbag and the switch 46 of the airbag. horn could be ejected with the envelope 51 of the inflated airbag. The tabs 53 and 55 of the outer and inner covers 44 and 48 of the air bag respectively together with the tabs on one side of the switch 46 of the horn, are thus fastened in an interlaced manner, between the lower ring portion 36 of the horn. the armature 30 of the steering wheel and the plate 60 of the plug to prevent the inner and outer covers 48 and 44 of the airbag from being ejected with the envelope 50 of the inflated airbag during activation of the airbag mechanism. Each tab 55 of the inner cover 48 of the air bag has a hole 68 through which the alternate fingers 66 pass. Also, the tabs 53 of the outer cover 44 of the air bag each have a hole through which the remaining fingers or pins 66 pass. The tabs 53 and 55 of the outer and inner covers 44 and 48 of the air bag respectively are offset by a distance such that when they are placed between the portion 36 of the ring and the plate 60 of the plug, the internal cover 48 the air bag is placed inside the outer cover 44 of the air bag, the fingers or pins 66 pass through the holes 68 and 69, with a free end of each finger 66 placed in a bore 70 in the portion 36 of lower ring. As shown in Figure 4, the switch 46 of the horn is placed between the inner cover 48 of the air bag and the outer cover 44 of the air bag. The outer cover 29 is above the outer cover 44 of the air bag. The finger 66 extends from the plate 60 of the plug passing through the tongue 53 of the outer cover 44 of the air bag. The finger 66 terminates in a bore 70 of the ring portion 36 of the armature 30 of the flywheel. In this way, when the air bag mechanism is activated, the casing 51 of the activated air bag bursts or explodes through the inner cover 48 of the air bag, the switch 46 of the horn, the cover 44. external of the air bag and the outer covering 29. Clamping the tabs 53 between the ring portion 36 and the plug plate 60, together with the fingers 66 passing through the holes 69 in the tabs 53 of the outer cover of the air bag, prevent the cover 44 of the air bag is ejected with the envelope 51 of the air bag. Also, the tongues 55 of the inner cover 48 of the air bag are held between the ring portion 36 and the plug plate 60, with the fingers 66 passing through the holes 68 of the tabs 55 of the inner cover 48 of the air bag, thus preventing the internal cover 48 of the air bag from being ejected with the envelope 51 of the air bag. As shown in Figures 5 and 6A, the structure for securing the combination of steering wheel and airbag in the arrow of the steering tube 22 may comprise a combination of worm gear 72 and a helical gear 74. The helical gear 74 includes a gear portion 76 and a threaded shaft portion 78. The threaded shaft portion 78 of the helical gear 74 extends from a face of the gear portion 76. A plurality of gear teeth 82 are formed at a single right angle about the periphery of the gear portion 76 of the helical gear 74. The worm gear 72 and the gear portions 76 of the helical gear 74 lie in a channel 80 of the plug plate 60. The channel 80 is in a plane defined by the plate 60 of the plug. The worm gear 72 includes a tooth 84 of the spiral gear which is adapted to drive the gear portion 76 and, in this way, rotates the helical gear 74 along a longitudinal axis A of the arrow 78. The worm gear 72 is actuated by inserting a drive mechanism (not shown) into the bore 86 of the gear 72 of screw and rotating worm gear 72. The perforation 86 is accessible from the outside of the assembled plug plate and the steering wheel assembly. The perforation 86 can be designed to require a special tool driving end to prevent theft of the combination 20 of the steering wheel and airbag. The rear face, the combination 20 of the steering wheel and air bag can be covered with a rear cover once the combination has been fixed to a steering tube. The rotation of the worm gear 72 in a first direction causes the helical gear 74 to rotate about the axis A. The arrow 78 of the helical gear 74 is received in a threaded bore 88 of the arrow 22 of the steering tube. In this way, when the worm gear 72 is operated, the helical gear 74 rotates about the axis A and the arrow 78 is urged towards the bore 88 to secure the combination 20 of the flywheel and airbag in the arrow 22 of the Steering tube. As shown in Figure 6A, the plug plate 60 includes a collar 90 extending from a lower face 65 of the plug plate 60. An inner surface 92 of the collar 90 engages an external tapered surface 94 of the arrow 22 of the steering tube as the threaded shaft 78 of the helical gear 74 engages the threaded bore 88 of the arrow 22 of the steering tube. The inner surface 92 will engage the tapered surface 94, wherein the internal diameter of the collar 90 is equal to the external diameter of the arrow 22 of the steering tube. As the coupling between the gear 74 and the threaded bore 88 propels the plate 60 of the plug towards the arrow 22, the inner surface 92 is forced towards the tapered surface 94, where the outer diameter of the tapered surface 94 is larger than the internal diameter of the collar 90. This creates a wedge or pressure adjustment between the collar 90 and the arrow 22 of the steering tube. The engagement of the inner surface 92 of the collar 90 with the tapered surface 94 of the arrow 22 of the steering tube creates a wedge closure between the plug plate 60 and the arrow 22 of the steering tube. This wedge closure maintains the plate 60 of the plug and, therefore, the combination 20 of the flywheel and air bag in the arrow 22 of the steering tube even when the gear 74 loosens. When it is desired to remove the wheel from the arrow 22, the worm gear 72 is rotated in the reverse direction which is used to tighten the helical gear 76. When the helical gear 76 is rotated in that direction, it will move axially upward, as shown in Figure 6A, and the portion 93 will abut against the air bag assembly 42. This provides a reaction surface and helps move the plug plate 60 and the collar 90 upwards to break the wedge closure between the collar 90 and the arrow 22. As shown in Figure 6B, the connection between the plate 60 of the plug and the spokes 34 of the armature 30 of the steering wheel includes a wedge closure feature that provides axial clamping between the armature 34 of the steering wheel and the plate 60 of the plug. The plate 60 of the plug includes a plurality of buttons 121 having a frusto-conical section adjacent to each opening 62. The spokes 34 of the armature 30 of the flywheel each have a seating surface 120 that receives the button 121. The seating surface 120 they are adjacent to the threaded holes 38 at the opposite ends of the spokes 34 and the armature 30 of the flywheel. The taper on the buttons 121 does not exactly correspond to the taper on the seating surfaces 120. The maximum diameter of the settlement 120 is less than the maximum width of the button 121. In this way when the bolts 40 are screwed into the perforations 38 and tightened securely, the buttons 121 are forced towards the seating surface 120 creating a wedge between the seating 120 and the button 121. This provides secondary clamping between the armature 30 of the steering wheel and the plate 60 of the plug. In the event that the plug bolts 40 are loosened or removed, the axial clamping between the button 121 and the seating 120 prevents the armature 30 of the steering wheel from moving from the plate 60 of the plug. The combination of steering wheel and air bag of the present invention can also be assembled without any wedge closure between the armature 30 of the steering wheel and the plate 60 of the plug. Also, the wedge closure can be reversed with the buttons on the frame and the settlements on the plug. Figure 6C shows an alternative structure for securing the combination 20 on an arrow 22 of the steering tube. The helical gear 174 includes the gear portion 76 and a threaded collar portion 178. The threaded collar portion 178 extends from one face of the gear portion 76 and includes a threaded inner surface 180. The arrow 22 of the steering tube has a threaded outer surface screwed into the threaded collar 178 of the helical gear 174. As with the helical gear shown in Figures 5 and 6A, the drive of the worm gear 72 rotates the helical gear 174 with the collar 178 threaded about the axis A. The threaded collar 178 is driven above the thread 188 of the arrow 22 of the steering tube to secure the combination 20 of the steering wheel and airbag in the arrow 22 of the steering tube. The plate 60 of the plug associated with the worm gear 72 and the worm gear 174 with the threaded collar 178 can include a collar that forms a wedge closure feature with the arrow 22 of the steering tube, as described in FIG. foregoing.

As shown in Figures 7 and 8, an alternative connection between the arrow 22 of the steering tube and the plug plate 60 includes a fastening bolt 91. The plate 60 of the plug includes a collar 90 extending from a face of the plate 60 of the plug remote from the exposed surface of the combination 20 of the flywheel and airbag. The collar 90 has a threaded bore 97 which screwably receives the threaded portion 96 of the arrow 22 of the steering tube. The plug plate 62 also has a second threaded bore 98 which remains essentially perpendicular to the threaded bore 94. The threaded bore 98 screwably receives the clamping bolt 91. In another alternative method for securing the combination 20 of the steering wheel and air bag to an arrow of the steering tube, the combination of steering wheel and air bag is placed above an arrow 22 of the steering tube. The free end of the arrow 22 of the steering tube is inserted into the bore 97. The tapered bore 97 of the collar 90 screwsly receives the threaded portion 96 of the arrow 22 of the steering tube. The tapered portion 94 of the arrow 22 of the steering tube engages the inner surface 93 of the collar 90, partially forming a wedge closure described above. The combination 20 of the steering wheel and airbag is then rotated to a predetermined stopping or stopping position. The threaded portion 95 of the collar 90 and the threaded portion 96 of the arrow 22 of the steering tube are designed to provide a desired number of rotations of the combination of steering wheel and airbag to reach the predetermined stopping or stopping position. The threaded portions 95 and 96 cooperate to provide the wedge closure between the arrow 22 of the steering tube and the plug plate 60. In the predetermined stopping or stopping position, the notch 95 of the arrow 22 of the steering tube is oriented towards the bore 98 of the plug plate 60. The clamping bolt 91 is then inserted into the bore 98 and tightened securely. The clamping bolt 91 also provides a clamping force which retains the plug plate 60 on the arrow 22 of the steering tube and, in this way, prevents the arrow 60 of the plug and the combination 20 of steering wheel and air bag turn in relation to arrow 22 of a steering tube and are loosened. As shown in Figures 9A and 10, another alternative connection between the combination 20 of the steering wheel and the air bag and the arrow 22 of the steering tube includes a bayonet type mechanism between the plug plate 20 and the arrow 22 of the steering tube. An opposite end of the arrow 22 of the steering tube includes a circumferential spiral groove 102 and an edge 104. The groove 102 extends from a free end 103 of the arrow 22 of the steering tube to the tapered outer surface 94. The slot 102 terminates in a stop or stop position positioned between the edge 104 and the tapered surface 94. The plate 60 of the plug includes a collar 90 having a bore 92 which receives the arrow 22 from the steering tube. The plate 60 of the plug also includes a tooth 106 adjacent the apex of the bore 92. The arrow 22 of the steering tube, including the free end 103 is received in the bore 92 of the plug plate 60. The tooth 106 slides towards the slot 102 starting at a point adjacent the free end 103 of the arrow 22 of the steering tube. The combination of the steering wheel and air bag is then rotated and the tooth 106 slides along the slot 102 to the stop or stop position adjacent the edge 104. Since the tooth 106 slides along the slot 102, the above-described wedge closure feature is formed between the tapered surface 94 of the arrow 22 of the steering tube and the inner surface of the bore 92 of the plug plate 60. The stop or stop position, the retaining pin 91 is inserted into the bore 98 and tightened securely against the arrow 22 of the steering tube, as described above. Figure 9A also shows the retaining ring 108 of the airbag component 50. The plate 60 of the plug includes a seat 110 for the inflator 52 of the air bag. Component 50 of the air bag is positioned above the inflator 52 of the air bag such that the air bag casing 51 surrounds the inflator 52. An air bag retention ring 108 is provided as part of the air bag. of component 50 of the air bag inside the envelope 51 of the air bag. When the inflator 52 is activated, a very large force (ascending in Figure 9) tends to dislodge the component 50 from the air bag from the plate 60 of the plug. The retaining ring 108 holds the inflator 52 in the seat 110 of the plug plate 60 and prevents the component 50 of the air bag from being pushed out of the plug plate 60, from the force provided by the inflator 52. The retainer ring 108 also seals the inflation gases within the casing 51 and prevents the escape of these gases, thereby ensuring proper filling of the air bag. The inflator 52 of the air bag has an edge 112 extending from the periphery of the inflator 52 at its base. The ring 108 of the air bag is above the edge 112 and is positioned around the periphery of the inflator 52 adjacent the edge 112. A plurality of fasteners 61 pass through the holes 63 in the plate 60 of the plug and finally through of the envelope 51 of the air bag and the ring 108. In one embodiment, the fasteners 61 comprise rivets. The inflator 52 of the air bag is placed in the seat 110 of the plate 60 of the plug. The air bag component 50 is positioned above the inflator 52 with the ring 108 positioned above the edge 112 of the inflator 52. The rivets 61 are inserted through the holes 63 and the hole 57 of the ring 108. The rivets 61 are then secured and placed securely to hold the ring 108 and the component 50 of the airbag in position, particularly during the activation of the inflator 52 of the airbag. Figure 9B shows an alternative air bag assembly including bolts 130 projecting from a lower face 65 of the plug plate 60. An air bag retention ring 128 is provided as part of the air bag component 50 within the air bag housing 51. In this embodiment, the ring 128 has a curve or wave that provides additional clamping resistance. The bolts 130 pass through the holes 157 of the ring 128, the envelope 51 of the air bag and the holes 63 of the plate 60 of the plug. The nuts 132 are bolted through bolts 130 and securedly secured. Initially, the ring only comes into contact with the envelope 51 of the air bag in a wave portion 129 of the retaining ring 128. As the nuts 132 are tightened, the bolt head 130 holds the locking ring 128 down until the ring 128 is essentially flat through the envelope 51 of the air bag. The edge 112 of the airbag inflator 52 sits in the seat 110 of the plug plate 60 and is securely held in place by the pins 130 and the ring 128. This ensures a relatively uniform holding force throughout the entire body. the periphery of the ring 128 with only four separate pins. The wave or curve can be designed to extend along a catenary curve that is selected to optimize its operation. Alternatively, manufacturing tolerances can make the idealized wave or curve design unimportant. Figure 11 shows a method for forming a steering wheel assembly, in accordance with the present invention. An outer cover 44 of the air bag is inserted into the ring portion 36 of the armature 30 of the flywheel, such that the tabs 53 of the outer cover 44 of the airbag abut against the ring portion 36. The armature 30 of the steering wheel and the outer cover 44 of the airbag are then inserted into a mold 130 corresponding to the desired configuration of the steering wheel. 130 urethane or other suitable resin is then injected from an appropriate resin source 132. The urethane fills the reaction injection mold 130 covering the upper flange portion 32. The spokes 34 and the outer cover 44 of the air bag. The lower ring portion 36, the opposite ends of the spokes 34 and the tabs 53 should not be covered with urethane to allow easy access of the ring portion 36 and the tabs 53 during the attachment of an assembly of the plug plate in the steering wheel set. In this way, a steering wheel assembly 132 having a resin coating 134 and a smooth external surface 29 is provided. The resin coating 134 is preferably integral with the outer cover 44 of the air bag. The outer cover of the air bag provides reinforcement to the resin cover 134 and helps to prevent fragmentation of the resin cover 134 during deployment of the air bag. The break seams are preferably formed in the resin cover 134 to facilitate deployment of the air bag. Figure 12 shows an alternative method for forming the steering wheel assembly 132. In this method, the external cover 134 of the steering wheel assembly 132 is simultaneously molded with an outer cover 44 of the air bag in the injection mold 130. In this way the outer cover 44 of the air bag integrates with the outer surface of the steering wheel. The armature 30 of the steering wheel is placed in the injection mold 130. The appropriate thermoplastic resin is injected from the resin source 136. The lower ring portion 36 is left exposed and the tabs 53 are formed during the injection molding process for further attachment to the plug plate assembly. Figures 13 to 15 illustrate a method for assembling a modular combination of steering wheel and air bag and a method for securing the combination to an arrow of the steering tube. Figure 13 illustrates a method for forming a sub-assembly 140 of the plug plate. The inflator 52 of the air bag is placed on the plate 60 of the plug. The component 50 of the air bag with the welded pins 130 is then positioned above the inflator 52. The bolts 130 are passed through the holes 63 of the plug plate 60. The component 50 of the air bag is then secured to the plate 60 of the plug by tightening the nuts 132 over the bolts 130. As the nuts 132 are tightened, the ring 128 placed in the component 50 of the bag air fastened downwardly is a casing 51 of the air bag as described above. The inner cover 48 of the air bag is placed above the component 50 of the air bag with the tabs 55 positioned above the fingers 66 of the plate 60 of the plug. The fingers or pins 66 extend through the holes 68 of the inner cover 48 of the air bag. The switch 46 of the horn is then placed above the inner cover 48 of the air bag. The switch 46 of the horn is adjacent to the wall 58 of the inner cover 48 of the air bag. As shown in Figure 14, the subassembly 140 of the plug plate is fixed to the flywheel assembly 132. The switch 46 of the horn and the inner cover 48 of the airbag are placed inside the outer cover 44 of the airbag of the sub-assembly 132 of the flywheel. In this way, the outer cover 44 of the air bag surrounds the inner cover 48 of the air bag. The walls 54 and 56 of the inner cover 48 of the air bag are adjacent, respectively, to the walls 47 and 49 of the outer cover 44 of the air bag. The switch 46 of the horn is positioned between the wall 58 of the inner cover 48 of the air bag and the wall 51 of the outer cover 44 of the air bag. The tabs 55 of the inner cover 48 of the air bag interlock with the tabs 53 of the outer cover 44 of the air bag. The alternate fingers 66 of the plug plate 60 pass through the holes 69 of the tabs 53. The fingers or pins 66 terminate in the perforations 70 of the ring portion 36. The bolts 40 are then inserted through the holes 62 and screwed into the threaded bores 38 of the armature 30 of the flywheel. As shown in Figure 15, the combination 20 of the steering wheel and the air bag is then placed on the arrow 22 of the steering tube. The combination 20 of the steering wheel and air bag includes a smooth one-piece outer covering 29 that faces the driver of a vehicle and the structure to secure the combination to the arrow 22 of the remote steering tube of the outer jacket 29. A tool 150 is then inserted into the combination 20 by coupling the structure 64. As mentioned above, the area 86 of the worm gear is accessible to receive the tool 150 and can be designed with a special configuration to prevent theft. The method then includes a tool 150 driven to drive the structure 64 of the gear set, securing 64 to the arrow 22 of the steering tube. The tool 50 rotates the worm gear 72 which rotates the gear 74 about the axis A. The threaded portion 74 is screwed into the threaded hole 88 securing the plate 60 of the plug and, thus, the combination 20 of the steering wheel and from the airbag to the arrow 22 of the steering. In another embodiment, the structure 64 comprises a plate 60 of the plug and the clamping bolt 91 shown in Figures 7 and 8 and the arrow 22 of the steering tube includes the threaded portion 96. In this method, the plate 60 of the plug of the combination 20 of the steering wheel and the air bag is positioned above the arrow 22 of the steering tube and rotated to a predetermined stop or stop position. The bolt 91 is then inserted into the threaded bore 98 and the tool 50 securely tightens the fastening bolt and the threaded bore 98. In another alternative embodiment, the structure 64 comprises the plate 60 of the plug and the clamping pin 91 shown in Figures 9 and 10, and the arrow 22 of the steering tube includes the slot 120 and the edge 104. The plate 60 of the plug, and the combination of the steering wheel and airbag are placed above the arrow 22 of the steering tube. The tooth 106 of the plug plate 60 moves along the slot 102 while the combination 20 of the flywheel and the air bag is rotated towards the arrow 22. When the tooth 106 reaches the stop or stop position With the predetermined location of the slot 102, the clamping bolt 91 is inserted into the threaded bore 98 of the plug plate 60 towards the recess on the opposite side of the casting. This places the clamping bolt 91 in double shear stress. The tool 150 rotates the clamping bolt 91 which is screwed into the threaded bore 98. The tool 150 securely tightens the clamping bolt 91 in the threaded bore 98. A preferred description of this invention has been disclosed; however, an operator skilled in the art will recognize that certain modifications will be within the scope of this invention. Due to that reason, the following claims must be studied in order to determine the true scope and content of this invention.

Claims (32)

1. R E I V I N D I C A C I O N E S: 1. A modular combination of steering wheel and air bag comprising: a steering wheel armature including an upper flange portion, a separate plug plate and a structure for securing the armature to the plug plate; The plug plate has a structure to ensure the combination in an arrow of the steering tube; and an air bag assembly. The modular combination of steering wheel and air bag according to claim 1, wherein the structure for securing the upper flange portion on the plug plate comprises a plurality of spokes extending from the upper flange portion at points separated, each having a threaded fastening hole at the opposite end of the beam and the plug plate includes a plurality of holes corresponding to the threaded fastening holes, and a plurality of bolts passing through the holes of the plate of the plug and that are received screwed into the threaded fastening holes. 3. The modular combination of steering wheel and air bag according to claim 2, wherein the steering wheel armature further includes a lower ring portion connecting the opposite end of the spokes. The modular combination of steering wheel and air bag according to claim 2, wherein each of the opposite ends of the spokes includes a seating and a plug plate includes a plurality of buttons adjacent to the corresponding holes, each having a generally tapered cross section, wherein the buttons are received at the seating surfaces such that an outer surface of the buttons forms a wedge closure with an inner surface of the seating surfaces. 5. The modular combination of steering wheel and air bag according to claim 4, wherein the settlement has a uniform diameter that is less than a maximum width of the buttons. 6. The modular combination of steering wheel and airbag according to claim 5, wherein the structure for securing the combination in an arrow of the steering tube includes a worm gear and a worm gear. 7. A modular combination of steering wheel and air bag comprising: a steering wheel armature including an upper flange portion, a plurality of spokes extending from the separate points of the upper flange portion each having an opposite end, and a portion of lower ring that connects the opposite ends; a plug plate fixed to the ring portion having a structure for securing the combination in an arrow of the steering tube; an air bag assembly positioned between the plug plate and the top flange portion. The modular combination of steering wheel and air bag according to claim 7, wherein each of the opposite ends includes a threaded fastening hole and the plug plate includes a plurality of corresponding holes, wherein the plug plate it is fixed to the ring portion with a plurality of bolts that pass through the corresponding holes and are screwed into the threaded fastening holes. 9. The modular combination of steering wheel and air bag according to claim 8, the air bag assembly comprises an air bag inflator and an air bag component positioned within an inner cover of the air bag, the air bag The inner cover of the air bag is positioned within an outer cover of the air bag, wherein the lower ring portion is placed around a base of the outer cover of the air bag. The modular combination of steering wheel and airbag according to claim 9, wherein the inner and outer covers of the airbag each have a plurality of interlacing tabs extending from a base of the tires., wherein the tabs are retained between the plug plate and the lower ring portion. The modular combination of steering wheel and air bag according to claim 10, wherein the plug plate includes a plurality of pins adjacent to the opposite rear edges of the plug plate, each of the tabs having a hole , and the ring portion has a plurality of perforations along the opposite lateral edges of the ring portion, wherein the pins pass through the tabs and terminate in the perforations. 12. A modular combination of handwheel and airbag comprising: a handwheel assembly including a top flange portion and a plug plate having a plurality of separate openings; and an air bag assembly including an inflator and an air bag envelope positioned around the inflator, the air bag assembly also includes an air bag retaining ring positioned within the envelope, around a base of the air bag. inflator and having a plurality of fixing holes, wherein the air bag assembly is fixed to the plug plate with a plurality of fasteners passing through the openings of the plug plate and the fixing holes. 13. The modular combination of steering wheel and air bag according to claim 12, wherein the inflator has an edge extending from the base of the inflator, the edge is placed between the retaining ring and the plug plate. The modular combination of steering wheel and air bag according to claim 13, wherein the plug plate includes a settling and the base of the inflator is placed within the settling. The modular combination of steering wheel and airbag according to claim 12, wherein the ring has a plurality of waves and each of the fasteners comprises a bolt and a pair of nuts, the bolt passes through the opening of the plug plate and the fixing hole and the waves are placed between the bolts in such a way that when the nut is tightened over the bolt, the waves are flattened above the envelope of the air bag, ensuring this way the retaining ring and the envelope of the air bag on the plug plate. 16. A modular combination of steering wheel and airbag comprising: a steering wheel assembly; a set of airbag secured on the steering wheel; wherein the handwheel assembly includes a plug plate, a worm gear and a complementary gear, the worm gear is adapted to drive the complementary gear in such a way that the complementary gear secures the combination on the shaft arrow the direction. 17. The modular combination of steering wheel and air bag according to claim 16, wherein the complementary gear includes a threaded arrow projecting from the rear face of the combination to be screwed into a threaded bore of the arrow of the tube. the direction. 18. The modular combination of steering wheel and air bag according to claim 16, wherein the complemental gear comprises a helical gear having a gear portion and a threaded shaft extending from a face of the gear portion and protruding from a rear face of the combination, the worm gear is adapted to rotate the helical gear along a longitudinal axis of the threaded shaft, the arrow of the steering tube includes a threaded bore which receives the screwed threaded shaft . The modular combination of steering wheel and airbag according to claim 18, wherein the plug plate is formed separately from the wheel portion of the steering wheel assembly, the plug plate includes a collar extending from a face opposite of the plug plate and which is placed around the threaded shaft and the arrow of the steering tube has a tapered portion at the opposite end of the arrow of the steering tube, where an internal diameter of the collar is smaller than a maximum width of the arrow of the steering tube along the tapered portion thereby forming a wedge closure between the collar and the arrow of the steering tube. 20. The modular combination of steering wheel and air bag according to claim 19, wherein the helical gear includes a button that extends from a face of the distal gear portion of the threaded shaft, wherein the rotation of the worm gear to disengage the worm gear from the arrow of the steering tube causes the button to come into contact with the air bag assembly, thereby forcing the collar and the plug plate away from the arrow of the steering tube and decoupling the wedge closure. 21. The modular combination of steering wheel and air bag according to claim 16, wherein the plug plate has a collar extending from one face, the worm gear and the complementary gear are placed in a channel of the plate of the plug, the complementary gear has a gear portion and a threaded shaft extending from the gear portion, the worm gear is adapted to rotate the complementary gear along a longitudinal axis of the arrow with the worm gear and the gear portion of the complementary gear placed in a plane defined by the plug plate. 22. The modular combination of steering wheel and air bag according to claim 16, wherein the complementary gear comprises a helical gear having a gear portion and a threaded collar extending from a face of the gear portion projecting from the rear side of the combination, the worm gear is adapted to rotate the worm gear along a longitudinal axis of the threaded collar, and the arrow of the steering tube includes a threaded outer surface screwed into the threaded collar. 23. The modular combination of steering wheel and airbag comprising: a steering wheel assembly; and an air bag assembly; The steering wheel assembly includes a plug plate and structure to secure the plug plate in a steering tube by placing the plug plate on the steering tube, rotating the plug plate on the steering tube to a position and using a stop to prevent additional relative rotation of the steering tube and plug plate. 24. The modular combination of steering wheel and air bag according to claim 23, wherein the structure for securing the plug plate in the steering tube includes threads in the plug plate and matching threads in the steering tube. such that the plug plate can be placed in the steering tube and rotated for a predetermined number of revolutions, and a locking or holding pin is then inserted to retain the plug plate in the predetermined position. 25. The modular combination of steering wheel and air bag according to claim 23, wherein the plug plate having a collar extending from an opposite layer, a tooth extending from an inner surface of the collar adjacent to an apex of the inner surface, a threaded bore essentially perpendicular to the collar and a clamping bolt, the arrow of the steering tube has an edge positioned adjacent the free end of the arrow of the steering tube and a circumferential spiral groove extending from the free end to the stopping or stopping position adjacent the edge, wherein the tooth is received in the groove and positioned adjacent to the edge, and the clamping bolt is screwed into the threaded bore, and an opposite end of the bore is received. pin bumps against the arrow of the steering tube to ensure the combination of steering wheel and air bag on the arrow of the steering tube on The modular combination of steering wheel and air bag according to claim 25, wherein the arrow of the steering tube includes a notch adjacent to the free end of the arrow of the steering tube distant from the edge and the opposite end of the clamping bolt abuts against the notch to prevent relative movement between the plug plate and the arrow of the steering tube. 27. A method for assembling a combination of steering wheel and air bag comprising the steps of: 1) providing a steering wheel frame comprising a portion of upper flange; 2) molding an outer cover around the flywheel armature; 3) Attach an air bag assembly to a plug plate to form a plug plate assembly; 4) Fix the plug plate assembly to the steering wheel assembly. The method for assembling a modular combination of steering wheel and airbag according to claim 27, wherein an outer cover of the airbag is fixed to the steering wheel armature before step 2. 29. The method for assembling a modular combination of steering wheel and air bag according to claim 28, wherein the outer cover of the air bag is also molded into the outer cover during step 2. 30. The method for assembling a modular combination of steering wheel and air bag according to claim 29, wherein the method includes placing a structure to secure a combination of handwheel and airbag in an arrow of the steering tube on the plug plate with a portion of the structure being accessible after step 4. 31. The method for assembling a modular combination of steering wheel and air bag according to claim 27, wherein the method includes colo Carry an inflator from the air bag into a seat on the plug plate, then place a component of the air bag over the air bag inflator with a retainer ring and integral fasteners above the bag inflator of air towards the plate of the plug and secure the ring and the component of the air bag in the plate of the plug. 32. The method for forming a modular combination of steering wheel and airbag according to claim 31, wherein securing the assembly of the plug plate in the steering wheel assembly includes passing a plurality of bolts through an equal number of Holes in the plug plate and securely tighten the bolts in the threaded holes. SUMMARY OF THE INVENTION A modular combination of steering wheel and air bag includes an air bag assembly, a steering wheel assembly and a separate plug plate. The combination is preassembled as a unitary component that can be easily fixed to an arrow of the steering tube. A taper or wedge closure is formed between the armature of the flywheel and the plug plate. The flywheel assembly includes a plurality of ribs or spokes extending from an upper flange portion of the flywheel assembly and a ring portion connecting the spokes to provide structural integrity and support for the flywheel assembly. The air bag assembly includes a retaining ring as part of an air bag component that provides easy and secure attachment of the air bag component to the plug plate. The combination of steering wheel and airbag of the invention comprises a structure for securing the combination in an arrow of the steering tube. One embodiment of the structure includes a worm gear and a complementary gear. The complementary gear can be a helical gear. In other embodiments, the combination is secured in an arrow of the steering tube by rotating the combination to a predetermined stopping or stopping position and inserting the retaining bolt into the threaded bore and tightly securing the bolt. A method for securing the combination in an arrow of the steering tube is disclosed. A method for forming and assembling a combination of steering wheel and air bag is also disclosed.