Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
  • B60R21/00—Arrangements or fittings on vehicles for protecting or preventing injuries to occupants or pedestrians in case of accidents or other traffic risks
  • B60R21/02—Occupant safety arrangements or fittings, e.g. crash pads
  • B60R21/04—Padded linings for the vehicle interior ; Energy absorbing structures associated with padded or non-padded linings
  • B60R21/05—Padded linings for the vehicle interior ; Energy absorbing structures associated with padded or non-padded linings associated with the steering wheel, steering hand lever or steering column
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60Q—ARRANGEMENT OF SIGNALLING OR LIGHTING DEVICES, THE MOUNTING OR SUPPORTING THEREOF OR CIRCUITS THEREFOR, FOR VEHICLES IN GENERAL
  • B60Q5/00—Arrangement or adaptation of acoustic signal devices
  • B60Q5/001—Switches therefor
  • B60Q5/003—Switches therefor mounted on the steering wheel
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
  • B62D—MOTOR VEHICLES; TRAILERS
  • B62D1/00—Steering controls, i.e. means for initiating a change of direction of the vehicle
  • B62D1/02—Steering controls, i.e. means for initiating a change of direction of the vehicle vehicle-mounted
  • B62D1/04—Hand wheels
  • B62D1/11—Hand wheels incorporating energy-absorbing arrangements, e.g. by being yieldable or collapsible
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
  • F16F7/00—Vibration-dampers; Shock-absorbers
  • F16F7/12—Vibration-dampers; Shock-absorbers using plastic deformation of members
  • F16F7/121—Vibration-dampers; Shock-absorbers using plastic deformation of members the members having a cellular, e.g. honeycomb, structure

Definitions

• the present invention relates to an impact energy absorber for a steering wheel of a vehicle.
• the present invention specifically relates to an impact-energy absorbing movable horn pad with a network of impact-energy absorbing members to absorb and dissipate an impact-energy uniformly, resulting from an application on an external in-plane load.
• a movable horn pad made of soft synthetic resin is arranged to cover a boss section of the steering wheel and an underlying armature, which is connected to a steering shaft.
• the horn pad is connected to a steering wheel body by means of snaps or guides arranged at the marginal portions of the back side of the horn pad.
• the horn pad is assembled to the steering wheel body by locking these snaps into corresponding latch portions of the steering wheel body.
• the horn pad In its assembled state, the horn pad is urged upwards from the steering wheel body by means of a biasing arrangement provided to the horn pad from the steering wheel body. Whenever the horn pad is depressed on the application of force, it moves inwards and actuates connected horn switches mounted on an armature of the steering wheel.
• An impact energy absorbing member generally made of sheet metal or polymer is disposed in a box-like pad, which is provided on top of the boss portion of the steering wheel and underneath the horn pad, to absorb an impact energy acting on the horn pad and to undergo deformation during the course of a crash or an accident.
• the deformation behavior of the energy absorbing member varies due to the changes in the incident angle of the impact force on the horn pad. For instance, depending on the incident angle of the impact force, the quantity of energy absorption also varies, resulting in non-uniform deformation of the energy absorbing member. In addition, in the event of any such deformation of the energy absorbing member, at the time of a crash or accident, the risk of dispersion of debris from the broken or deformed energy absorbing member, due to its rigid construction, is also high, which may in turn cause injuries to a driver.
• the intensity of the impact force acting upon the horn pad also causes dislocation of the horn pad from the steering wheel body, which also contributes to the uncontrolled or reduced dissipation of the impact energy through the energy absorbing member.
• Indian Patent Application No. 589/MUM/2007 discloses a steering wheel horn pad 1 with an energy absorbing structure 2 with a through hole 3, at the center portion of the horn pad 1 and ribs 4 on either side of the energy absorbing structure 2, to absorb a portion of energy and ribs 6 to accommodate horn actuating means.
• the energy absorbing structure 2 is located at the center portion the horn pad is co-axial to the steering wheel fastener and impacts directly on to it at the time of impact, which by nature of its construction, exerts a piercing force on the horn pad 1 through the energy absorbing structure 2.
• the ribs 4 come into contact with armature initially and thereafter the absorbing structure 2, resulting in an inefficient absorption of energy.
• this known arrangement due to the absence of a direct connectivity or network between the energy absorbing structure 2 and the ribs 2 and 6 the flow of dissipation of energy between the absorbing structure 2 and ribs 2 and 6 is discontinuous and not uniform across the horn pad 1.
• the desired impact-energy absorbing members of a horn pad shall have an optimum buckling and collapsing property, in order to effectively absorb the impact-energy. It is also preferable to provide a horn pad with impact-energy absorbers, having impact-energy absorbing cum locking arrangement, which can retain the horn pad to the steering wheel assembly, even on the application of the impact force.
• the primary object of the present invention is to provide a network of impact- energy absorbing members such as primary, secondary and peripheral impact-energy absorbing members, for a movable horn pad of a steering wheel, which can buckle and collapse (undergo deformation) under an impact and uniformly absorb and dissipate the corresponding impact-energy.
• An object of the present invention is to provide a network of impact-energy absorbing members for a movable horn pad of a steering wheel, to prevent the scattering of debris of the deformed impact-energy absorbing members and the horn pad, at the time of application of impact force on the horn pad.
• Another object of the present invention is to provide impact-energy absorbing members for a movable horn pad of a steering wheel, with a network of plurality of impact-energy absorbing members, which are positioned offset to central axis of the steering wheel column, to effectively absorb and uniformly dissipate the impact energy.
• the present invention provides a steering wheel with an impact-energy absorbing movable horn pad connected to an armature.
• a network of impact-energy absorbing members includes a primary impact-energy absorbing member connected to a movable horn pad, to absorb the first portion of impact energy from an external in-plane load.
• a set of secondary impact-energy absorbing members connected to the primary impact-energy absorbing member, to disperse and absorb a second portion of the impact energy radiating from the primary-impact energy absorbing member.
• a peripheral impact-energy absorbing arrangement connected to the primary and secondary impact-energy absorbing members, to absorb residual impact energy and to retain the horn pad with the armature of the steering wheel.
• This managed energy absorption provides a better deceleration profile and reduces the chances of uncontrolled buckling of the energy-absorbing members or structures.
• the use of a network of impact energy-absorbing arrangements, connected to the horn pad also substantially reduces the risk of cracking or fragmenting of the horn pad assembly during the impact thereby exposing a driver to injurious sharp edges.
• FIG. 1 is a perspective view of a steering wheel with a movable horn pad.
• FIG. 2 is an exploded perspective view of the steering wheel assembly with an impact-energy absorbing movable horn pad of the present invention depicting primary, secondary and peripheral impact absorbing arrangements.
• FIG. 3a is a top view of the horn pad of the present invention showing a peripheral impact-energy absorbing arrangement in a disengaged position.
• FIG. 3b is a partially exploded detail view b of a FIG. 3, showing the peripheral impact-energy absorbing arrangement in a disengaged position.
• FIG. 4a is a top view of the horn pad of the present invention and FIG. 4b and 4c are sectional views C-C and D-D' of FIG. 4a depicting the arrangement of the peripheral impact-energy absorbing arrangement in an engaged position with the armature of the steering wheel.
• FIG. 5 is a perspective inner view of the impact-energy absorbing horn pad of the present invention depicting a network of primary, secondary and peripheral impact-energy absorbing members.
• FIGS. 6a, 6b, 6c and 6d depict perspective exemplary views of network of primary and secondary impact-energy absorbing members of the horn pad of the present invention.
• FIG. 7 a is a cross-sectional view of a network of primary and secondary impact- energy absorbing members of the horn pad of the present invention, in an assembled position.
• FIG. 7b is a cross-sectional view of a network of primary and secondary impact- energy absorbing members of the horn pad of the present invention, shown in deformed position, with the horn pad held together with an armature of the steering wheel.
• FIG. 8 is a graphical representation of the impact energy dissipation curve of the impact-energy absorbing movable horn pad of the present invention, on application of an external in-plane load.
• the present invention provides a horn pad with an energy absorbing member and a latch arrangement, as hereinafter described.
• FIG. 1 is a plan view of an impact-energy absorbing movable horn pad 201mounted on a steering wheel 100 and connected to an annular body 102, through its peripheral portions.
• FIG. 2 is an exploded perspective view of the steering wheel assembly 200.
• An armature 203 which forms a basic supporting frame work for the steering wheel assembly 200, is made of a lightweight die-casting material, such as an aluminum alloy.
• the armature 203 is generally provided with a central lower portion 203a, to which a column shaft 204 of the steering wheel 200 is connected.
• Collars 203b of the armature 203 extend laterally from the central lower portion 203a and are connected peripherally, to the annular body 202, at different locations, as shown in FIG.2.
• the connectivity of the collars 203a of the armature 203 to the annular body 202 of the steering wheel 200 is shown, at three different location points, in an exemplary manner, to render a substantially inverted triangular configuration to the armature 203.
• the location points of the collars 203b on the annular body 202 can be suitably varied depending upon the desired shape and configuration of the steering wheel 200 and the horn pad 201.
• An impact-energy absorbing movable horn pad 201 is integrally connected to the armature 203 and the annular body 202, of the steering wheel assembly 200, through the armature collars 203b as shown in FIG.2.
• An intervening space G (as shown in FIG.7a) is arranged between the impact-energy absorbing movable horn pad 201 and the armature 203 to facilitate the longitudinal movement of the horn pad 201 towards the armature 203.
• the movable horn pad 201 is connected to the armature 203 and arranged parallel to the central axis A-A " of a steering wheel column shaft 204 and offset to axis B-B" of the steering column shaft 204.
• a plurality of impact-energy absorbing members 206 which are networked together, are connected to the inner surface of the horn pad 201 and positioned to extend longitudinally towards the armature 203.
• the arrangement of the impact-energy absorbing members 206 is more fully described infra.
• At least a pair of locking members 209a and 209bwith proximal and distal ends are provided on the inner peripheral surfaces of the horn pad 201 to project longitudinally towards the armature 203, as shown in FIG.2.
• the proximal ends of the locking members 209a and 209b are integrally connected to the inner peripheral surface of the impact- energy absorbing movable horn pad 201 by molding or by any other suitable connecting arrangement such as thread, press-fit etc.
• the locking members 209a and 209b are positioned with an intervening space, laterally, across the inner surface of the impact- energy absorbing movable horn pad 201 and positioned substantially parallel to each other.
• the impact-energy absorbing movable horn pad 201 is mounted on the armature
• the locking members 209a and 209b are in the form of cylindrical projections having surface profiles suitable for locking with the sockets 205a and 205b respectively.
• the impact-energy absorbing movable horn pad 201 of the present invention is provided with a network of primary, secondary and peripheral impact-energy absorbing members as hereinafter described by referring to the accompanied drawings.
• a peripheral impact-energy absorbing arrangement including impact-absorbing horn pad-armature locking members 209c and 209d are provided on the inner surface of the horn pad 201 as shown in FIG.2, which are also used to connect the horn pad 201 with the armature 203, through collar-sockets 205c and 205d respectively.
• a shell 207 is connected to the armature collars 203b, through the column shaft 204, to form a holding-chamber 208 around the central cavity portion 203a and the collars 203b of the armature 203.
• the holding chamber 208 also functions as a collector for debris, if any, arising out of the deformed horn pad 201 at the time of impact.
• Horn switch assemblies 210 are also mounted on the armature 203 and connected to the horn pad 201and armature through sockets 206a and 206b, for their actuation, on depression of the horn pad 201.
• the peripheral impact-energy absorbing arrangement includes, at least a pair of impact-absorbing horn pad-armature locking members 309c and 309d, which are cylindrical protrusions extending longitudinally from the inner surface of the horn pad 201, through their proximal ends as shown in FIG.3a.
• the impact-absorbing horn pad-armature locking members 309c and 309d are co-axially positioned along respective passage axes of the collar-sockets 305c and 305d.
• Spatially -arranged protrusions 311 such as rings are arranged on the outer surfaces of distal ends of the impact-absorbing horn pad-armature locking members 309c and 309d, with intervening spaces between them to render multi-stage locking of the impact- absorbing horn pad-armature locking members 309c and 309d with the collar-sockets 305c and 305d of the armature 303, both in the state of assembly and after the impact, as more fully described infra.
• the ring configuration as provided on the surfaces of impact- absorbing horn pad-armature locking members 309c and 309d can be suitably changed with other surface profiles such as thread, latch or any other arrangements, which can provide the desired locking with the collar-sockets 305c and 305d of the armature 303.
• the impact-absorbing horn pad-armature locking members 309c and 309d are made of suitable load-bearing polymeric material, such as soft synthetic resin. The material thus chosen possesses a desired tolerance of flexural loads, a capacity to absorb impact energy and to undergo buckling and partial deformation, on the application of an external in-plane load.
• the distal ends are provided, optionally, with serrations, slits or perforations 309e and 309f, along with the spatially-arranged protrusions 311 to facilitate an easy buckling, deformation, dispersal or lateral movement of the tips of the impact-absorbing horn pad-armature locking members 309c and 309d, inside the collar- sockets 305c and 305d, application of the external in-plane load.
• the surface configuration of the impact-absorbing horn pad-armature locking members 309c and 309d is circular or non-circular with circumferential protrusions and serrations.
• the non-circular surface configuration can be rectangular, hexagonal, polygon or any other suitable profiles.
• the impact-absorbing horn pad-armature locking members 309c and 309d are provided with extended lengths to allow the transmission of the impact energy at the time of impact and further dissipation thereof.
• the impact-absorbing horn pad-armature locking members 309c and 309d are also arranged to absorb the applied external in-plane load, to great extent, and hold the horn pad 201 with the armature 303, even after undergoing deformation.
• FIGS. 4a and 4b a mating or locking arrangement of the impact-absorbing horn pad-armature locking members 409c and 409d with collar sockets 405c and 405d of the armature 403, in its assembled position, is shown in FIGS. 4a and 4b (a detailed view of section C-C of FIG.4a) and 4b.
• the inner surface profile of the collar sockets 405c and 405d are provided with suitable locking-slots corresponding to the outer profile of the horn pad-armature locking members 409c and 409d, as shown in FIG.4a and 4b. Accordingly, in an assembled state, impact-absorbing horn pad-armature locking members 409c and 409d, with extended lengths X, when urged towards the armature 403, engage with the collar sockets 405a and 405d, in a press-fit locked position, in a multi-lock mode.
• the collar sockets 405c and 405d are provided with lengths Y of socket greater than the lengths X of the impact-absorbing horn pad-armature locking members 409c and 409d, as shown in FIG.4C (a detailed view of section D-D' of FIG.4a), to permit longitudinal travel of impact-absorbing horn pad-armature locking members 409c and 409d, inside the collar sockets 405c and 405d, in the event of the application of the impact force on the horn pad 201.
• a primary impact-absorbing member 512 is integrally connected to the inner surface of the horn pad 201.
• the primary impact-absorbing member 512 is a hollow cylindrical member integrally connected to the horn pad 201.
• the primary impact absorbing member 512 is arranged to extend longitudinally from the inner surface of the horn pad 201, towards the armature.
• the arrangement of the primary impact-absorbing member 512 is not co-axial to the central axis A-A' of the steering wheel column shaft 204 (as shown in FIG. 7a) of the steering wheel and positioned offset to the column shaft 204(as shown in FIG. 7 a).
• the primary impact-absorbing member 512 is provided with an extended length, to enable it to come into contact, first, with the armature, away from its central portion where the column shaft is connected, upon the application of the impact force on the horn pad 501.
• the primary impact-absorbing member 512 On impact, the primary impact-absorbing member 512, while absorbing a first portion of the impact energy generated by an in-plane load on the horn pad 201, due to the impact of head portion of a user (driver), undergoes an initial buckling and thereafter collapsing, before transmitting the corresponding second portion of the impact energy further to other energy-absorbing members.
• the distal end of the primary impact-absorbing member 512 is terminated in the intervening space G (as shown in FIG. 7 a) arranged between the armature and the primary impact-absorbing member 512.
• the primary impact-energy absorbing member 512 is made of suitable load-bearing polymeric material, such as soft synthetic resin. The material thus chosen will have a desired tolerance of flexural loads and a capacity for partial deformation, on the application of the external in-plane load.
• Secondary impact-energy absorbing members 514 and 515 are integrated to the inner surface of the horn pad 201 with their proximal ends and distributed uniformly across the length and breadth of the inner surface of the horn pad 201.
• the arrangement of the secondary impact-energy absorbing members is a network of longitudinal and transverse impact-absorbing members 514 and 515, tubular impact-energy absorbing members 513 and an inner-peripheral impact-absorbing member 517.
• the longitudinal and transverse impact-absorbing members 514 and 515 are non- cylindrical structures, optionally provided with perforations, which are integrated to the inner surface of the horn pad 201.
• the longitudinal and transverse impact-absorbing members 514 and 515 are distributed on the inner surface of the horn pad 201 and arranged to extend from the horn pad 501, towards the armature and terminated in the intervening space between the armature and the longitudinal and transverse impact-absorbing members 514 and 515.
• the longitudinal and transverse impact-absorbing members 514 and 515 are integrally connected to each other to form a network or grid of impact-absorbing members.
• the network of the longitudinal and transverse impact-absorbing members 514 and 515 is further integrally connected to the primary impact absorbing-member 512, to absorb the second portion of the impact energy from the primary impact absorbing-member 512, on the application of the impact force on the horn pad 501.
• the network of the longitudinal and transverse impact-absorbing members 514 and 515 is provided with openings between the adjacent sets of longitudinal and transverse impact-absorbing members 514 and 515, termed as apertures 516, which are large enough to allow the absorption of the secondary impact-energy from the primary impact-absorbing member 512 and the dissipation thereof.
• the secondary impact-energy absorbing members 514 and 515 are made of suitable load-bearing polymeric material, such as soft synthetic resin.
• the material thus chosen will have a desired tolerance of flexural loads and a capacity for partial deformation, on the application of an external in-plane load and on receiving the radiated impact energy from the primary impact-absorbing member 512.
• the junction strength i.e. the meeting points of the longitudinal and transverse impact-absorbing members 514 and 515, is also significant in imparting a uniform dissipation of the impact energy across the network of longitudinal and transverse impact-absorbing members' 514 and 515. Accordingly, the junction points where the longitudinal and transverse impact-energy absorbing members 514 and 515 meet are provided with tubular structures or nodes 513. The nodes 513 are arranged longitudinally to extend towards the armature and their distal ends terminate in the intervening space between the armature and the nodes 513.
• the central diameters of the nodes 513 are smaller than the diameter of the primary impact-absorbing member 512.
• the nodes 513 are connected to the primary impact- absorbing member 512 and the longitudinal and transverse impact-absorbing members 514 and 515 to receive the second portion of the impact or kinetic energy from the primary impact-absorbing member 512, upon the application of the impact force on the horn pad 201
• the nodes 513 are tubular in nature to facilitate an effective dissipation of the kinetic energy of the impact force.
• the nodes 513 are provided at the junction points of the longitudinal and transverse impact-absorbing members 514 and 515 to provide a desired rigidity and tensile drawing strength to the longitudinal and transverse impact-absorbing members 514 and 515.
• the nodes 513 assist in the uniform dissipation of the kinetic energy, across the longitudinal and transverse impact-absorbing members 514 and 515.
• the longitudinal and transverse impact-absorbing members 514 and 515 are shorter than the primary impact-absorbing member 512.
• the longitudinal and transverse impact-absorbing members 514 and 515 that are connected to the primary impact-absorbing member 512 can be constructed in any suitable shapes and configurations as depicted in FIGS. 6a, 6b, 6c and 6d.
• the primary and secondary impact-absorbing members 612 as shown in FIGS. 6a, 6b, 6c and 6d are provided with perforations 618 and 619, to facilitate an effective absorption of the kinetic energy from the armature.
• the perforations 618 and 619 also facilitate a controlled deformation of the primary impact-absorbing member 612, while absorbing the first portion of the kinetic or impact energy.
• the longitudinal and transverse impact-absorbing members 514 and 515 are suspended in the central cavity of the armature of the steering wheel, by providing an intervening gap G (as shown in FIG. 7a) between the armature surface and the bottom portion of the longitudinal and transverse impact-absorbing members 514 and 515.
• the longitudinal and transverse impact-absorbing members 514 and 515 and the primary impact-absorbing member 512 are covered peripherally with an inner-peripheral impact-energy absorbing member 517 to envelope the network of the impact-energy absorbing members.
• the inner-peripheral impact-energy absorbing member 517 is of desired density, preferably of a polymer material with a higher density than that of the material of the other impact-energy absorbing members, to act as an enclosure or envelope for the primary impact-energy absorbing member 512 and the secondary impact-energy absorbing members 514 and 515 to prevent the scattering of the debris arising out of the deformation of the impact-absorbing members during the course of the impact.
• the impact-energy absorbing members of the horn pad of the present invention are positioned to uniformly absorb kinetic energy by buckling and collapsing and to dissipate the kinetic or impact energy applied on the horn pad, which is in the form of an external in- plane load in a pre-designated and controlled manner, irrespective of the angle of incidence of the longitudinal force acting upon the horn pad at the time of the impact or accident.
• FIGS. 7a and 7b in view of the offset arrangement of the horn pad along with its impact-energy absorbing members 712 and 715 to the axis of the steering wheel column shaft, the collision of the primary impact-energy absorbing member 712 is avoided on the column shaft 704 and the impact energy is uniformly dissipated across the impact-energy absorbing members.
• the deformation of the impact-energy absorption is also uniform as shown in FIG. 7b, where the first portion of the impact energy is absorbed by the primary impact-energy absorbing member712, which deforms substantially and thereafter the second portion of the impact energy is absorbed by the secondary and peripheral absorbing members. It can also be seen from FIG. 7b that even after the deformation of the horn pad under the impact force, the horn pad is prevented from ejecting from the steering wheel assembly and retained to the armature of the steering wheel.
• the impact-energy absorbing horn pad of the present invention also meets the desired parameters of the impact-energy dissipation, such as slow dissipation for the first 10msec under the process of buckling and thereafter collapsing for next 10 to 15 msec.
• This controlled dissipation of the impact-energy facilitates maximum energy absorption so that when the head portion of a person in a driver's seat of a vehicle touches the horn pad 201, no hard contact with any rigid part of the assembly is made by the head portion.
• This aspect of impact-energy dissipation is graphically represented in FIG. 8, by plotting the parameters of a simulated impactor test using the horn pad 201 of the present invention the parameters of velocity, time and acceleration inverse, to show an impactor' s deceleration and absorption of the impact-energy, under standard test conditions.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Acoustics & Sound (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Transportation (AREA)
• Steering Controls (AREA)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

Country Status (2)

Cited By (1)

Citations (8)

• 2013
  • 2013-01-07 IN IN153CH2012 patent/IN2012CH00153A/en unknown
  • 2013-01-07 WO PCT/SE2013/050004 patent/WO2013105890A1/en not_active Ceased

Patent Citations (8)

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