WO2012097354A1

WO2012097354A1 - Jounce bumper assembly and gas spring assembly including same.

Info

Publication number: WO2012097354A1
Application number: PCT/US2012/021398
Authority: WO
Inventors: Paul P. Koeske
Original assignee: Firestone Industrial Products Company, Llc
Priority date: 2011-01-14
Filing date: 2012-01-14
Publication date: 2012-07-19

Abstract

A jounce bumper can include a side wall that at least partially defines a cavity. The jounce bumper also includes a plurality of retaining fingers. The retaining fingers extend from along the side wall and project into the cavity. The retaining fingers have a curvilinear cross-sectional profile and terminate at a corner. The cavity and retaining fingers are dimensioned to receive and abuttingly engage a bumper mount. A gas spring assembly can include the jounce bumper and the bumper mount. A kit can include the jounce bumper and the bumper mount as separate components.

Description

JOUNCE BUMPER ASSEMBLY AND GAS SPRING ASSEMBLY

INCLUDING SAME.

BACKGROUND

[0001] The subject matter of the present disclosure broadly relates to the art of gas spring devices and, more particularly, to a jounce bumper that is capable of providing improved retention performance under laterally-applied loads. As one example, such a jounce bumper can include curved snap fingers that engage an associated mounting component. A gas spring assembly including such a jounce bumper is also disclosed.

[0002] The subject matter of the present disclosure may find particular application and use in conjunction with suspension systems of wheeled vehicles, and may be described herein with reference thereto. However, it is to be appreciated that the subject matter of the present disclosure is also amenable to broad use in a wide variety of other applications and environments, and that the specific uses shown, described and/or otherwise referred to herein are merely exemplary. For example, the subject matter of the present disclosure could be used in gas spring assemblies for support structures, height adjusting systems and actuators associated with industrial machinery, components thereof and/or other such equipment.

[0003] Wheeled motor vehicles of most types and kinds include a sprung mass, such as a body or chassis, for example, and an unsprung mass, such as two or more axles or other wheel-engaging members, for example, with a suspension system disposed therebetween. Typically, a suspension system will include a plurality of spring devices as well as a plurality of damping devices that together permit the sprung and unsprung masses of the vehicle to move in a somewhat controlled manner relative to one another. Movement of the sprung and unsprung masses toward one another is normally referred to in the art as jounce motion while movement of the sprung and unsprung masses away from one another is commonly referred to in the art as rebound motion.

[0004] Generally, the range of motion of a suspension system extends between a first or fully compressed condition and a second or fully extended condition. To eliminate contact between opposing portions of the sprung and unsprung masses, contact between opposing portions of components of the suspension system or contact between any combination thereof, jounce bumpers are commonly installed in one or more areas of the vehicle to prevent such opposing portions from directly impacting one another. Thus, during jounce motion of the suspension system, an opposing component will contact the jounce bumper rather than impacting the component on or near which the jounce bumper is mounted.

[0005] Jounce bumpers of a variety of types, kinds and configurations have been developed and are commonly used. Though the size and shape of jounce bumpers vary widely, known jounce bumpers can generally be grouped into two categories, namely, compliant jounce bumpers and rigid jounce bumpers. The former are commonly formed from materials capable of relatively high deflections under load, and are often formed from rubber or elastomeric foam compounds.

[0006] Generally, compliant jounce bumpers act to cushion or otherwise soften the impact that would otherwise be associated with a sudden movement toward a full jounce condition. As such, compliant jounce bumpers are well suited for use in relatively light duty applications, such as use in the suspension systems of passenger vehicles and light trucks, for example, where ride comfort is a more significant factor. Additionally, the materials from which such compliant jounce bumpers are formed is normally capable of withstanding at least some amount of lateral deflection, such as would be due to a laterally-applied load, without undergoing permanent deformation or another undesirable alteration of performance characteristics. Furthermore, suspension systems used in passenger and other light-duty applications typically permit a relatively small or otherwise reduced amount of lateral displacement, which is normally well within the capability of known compliant jounce bumpers to withstand.

[0007] Unfortunately, the elastomeric materials that result in compliant jounce bumpers being so well suited for high-comfort, light-duty applications have generally been found to be quite poorly suited for high-load and/or heavy-duty applications. One exemplary reason for such a lack of suitability for use in heavy-duty applications relates to the elastomeric nature of the material itself. More specifically, for a given compliant jounce bumper to have a suitable compressed height (i.e., a compressed height that will be sufficient to inhibit contact between opposing suspension components under a heavy load), the corresponding free height of such a given compliant jounce bumper would likely be great enough to adversely affect the overall travel or other performance characteristics of the suspension system. Said differently, the elastomeric material would have to compress so much to support the high-load condition that the unloaded height of the material could result in the compliant jounce bumper undesirably interfering with the performance of the suspension system or components thereof.

[0008] Other exemplary difficulties with the use of compliant jounce bumpers under high-load and/or heavy-duty conditions involve the performance of such compliant bumpers when contacted at relatively high angles. As has been previously mentioned, in order to support a substantial load at a given height, a compliant bumper will normally possess a taller free height due to its high level of axial strain. Many suspension geometries allow the mounting spring surfaces to articulate at an angle relative to one another, such as in a trailing arm-type suspension, for example. On such suspensions, a taller compliant jounce bumper would contact the opposing structural member much earlier in the suspension travel and at a greater angle. When contacted at a relatively high angle, such as an angle of about 10 degrees or more, for example, a compliant jounce bumper will deflect laterally. This can undesirably increase the possibility of interference with other components and can also undesirably reduce suspension travel. In contrast, a less compliant jounce bumper would be able to utilize a lower free height and would normally contact the opposing structural member at a later point during suspension travel. Thus, the structural member will typically contact a less-compliant jounce bumper at a lower angle, which may thereby minimize the aforementioned issues with compliant jounce bumpers. One further issue involves maintaining the attachment of such compliant jounce bumpers on a corresponding securement feature under such high levels of lateral displacement and/or at higher contact angles. [0009] Oppositely, rigid jounce bumpers are commonly formed from materials that deflect a relatively small amount under load, such as high strength and/or fiber reinforced plastic materials, for example. Rigid jounce bumpers are not normally considered to be well suited for use in light duty applications (e.g., passenger vehicle applications) because of the minimal deflection and corresponding ride harshness that can be associated with the use of such rigid jounce bumpers. However, rigid jounce bumpers are well suited for heavy duty applications, such as in truck, tractor- trailer and other over-the-road vehicle applications, for example, where it is desirable to provide a sacrificial component that can prevent impacts between more permanent and/or expensive components. Additionally, it is often desirable to lower trucks, trailers or other vehicle bodies onto the jounce bumpers to provide a solid foundation for loading and/or unloading of the vehicle body.

[0010] Accordingly, rigid jounce bumpers provide a variety of favorable performance characteristics associated with use in heavy duty and certain other applications. However, one disadvantage of known rigid jounce bumpers is that, in some cases, known designs may not be well suited for accommodating laterally- applied or side load conditions. One example of such a condition can occur when a rigid jounce bumper is axially compressed between opposing structural members and the structural members are then moved laterally relative to one another. Such an action is sometimes referred to in the art as a "scrub load" and can generate a shearing action on the rigid jounce bumper that can result in permanent deformation or other undesirable alterations in the jounce bumper due to the highly rigid (i.e., substantially non-elastomeric) nature of the material forming the same. For example, such scrub loads and/or other lateral load conditions can result in permanent deflection of the snap fingers utilized in known rigid jounce bumper constructions. Such deflection is normally in a radially-outward direction and can undesirably result in the disengagement or other separation of the snap fingers from the mounting component on or along which the rigid jounce bumper is secured.

[0011] It is believed desirable to develop a jounce bumper, as well as a gas spring assembly including the same, that is/are capable of providing improved retention of the jounce bumper on the mounting component during use of the gas spring assembly under laterally-applied and/or other load conditions, and/or overcoming other disadvantages of known constructions while maintaining a relatively low cost of manufacture and ease of assembly.

BRIEF SUMMARY

[0012] One example of a jounce bumper in accordance with the subject matter of the present disclosure that is dimensioned to receive an associated bumper mount can include a side wall extending peripherally around a longitudinal axis and at least partially defining a bumper cavity. A plurality of retaining fingers can extend longitudinally from along the side wall and project radially-inwardly from the side wall into the bumper cavity. The plurality of retaining fingers can be disposed in spaced relation to one another around the longitudinal axis along the side wall. The plurality of retaining fingers can include at least one radius of curvature in cross section with the cross section taken from along a reference plane that contains the longitudinal axis.

[0013] One example of a gas spring assembly in accordance with the subject matter of the present disclosure can include a first end member and a second end member spaced longitudinally from the first end member such that a longitudinal axis is defined therebetween. A flexible wall can extend peripherally around the longitudinal axis. The flexible wall can be secured along the first and second end members such that a spring chamber is at least partially defined therebetween. A jounce bumper can be disposed within the spring chamber and can be operatively connected to one of the first and second end members. The jounce bumper can include a side wall extending peripherally around a longitudinal axis and at least partially defining a bumper cavity. A plurality of retaining fingers can extend longitudinally from along the side wall and project radially-inwardly from the side wall into the bumper cavity. The plurality of retaining fingers can be disposed in spaced relation to one another around the longitudinal axis along the side wall. The plurality of retaining fingers can include at least one radius of curvature in cross section with the cross section taken from along a reference plane that contains the longitudinal axis. [0014] One example of a kit in accordance with the subject matter of the present disclosure for use with an associated gas spring assembly can include a jounce bumper and a bumper mount. The jounce bumper can include a side wall extending peripherally around a longitudinal axis and at least partially defining a bumper cavity. A plurality of retaining fingers can extend longitudinally from along the side wall and project radially-inwardly from the side wall into the bumper cavity. The plurality of retaining fingers can be disposed in spaced relation to one another around the longitudinal axis along the side wall. The plurality of retaining fingers can include at least one radius of curvature in cross section with the cross section taken from along a reference plane that contains the longitudinal axis. The bumper mount can include an outer side wall that extends longitudinally from a first end toward a second end. The bumper mount can include a groove extending into the bumper mount from along the outer side wall. The outer side wall can be dimensioned to compressively engage the side wall of the jounce bumper. The groove can be dimensioned to receivingly engage the plurality of retaining fingers. In some cases, the bumper mount can have a width dimension and a length dimension that is at least 70 percent greater than the width dimension. In other cases, the length dimension of the bumper mount can be at least 90 percent greater than the width dimension of the bumper mount. In some cases, the groove can be spaced away from the first end toward the second end a distance that is at least 20 percent greater than the width of the bumper mount. In other cases, the distance that the groove is spaced from the first end can be at least 40 percent greater than the width of the bumper mount.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] FIG. 1 is a side view, in partial cross section, of one example of a gas spring assembly that includes a jounce bumper in accordance with the subject matter of the present disclosure.

[0016] FIG. 2 is a top plan view of the exemplary jounce bumper in FIG. 1 .

[0017] FIG. 3 is a cross-sectional side view of the jounce bumper in FIGS. 1 and 2 taken from along line 3-3 in FIG. 2. [0018] FIG. 4 is an enlarged view of the portion of the jounce bumper in FIGS. 1 - 3 identified in Detail 4 of FIG. 3.

[0019] FIG. 5 is an enlarged view of the portion of the jounce bumper and mounting stud in FIGS. 1-4 identified in Detail 5 of FIG. 1.

DETAILED DESCRIPTION

[0020] Turning, now, to the drawings wherein the showings are for the purpose of illustrating examples of the subject matter of the present disclosure and which are not intended as a limitation of the same, FIG. 1 illustrates one example of a gas spring assembly 100 that is disposed between opposing structural components, such as upper and lower structural components USC and LSC of an associated vehicle (not shown), for example. Gas spring assembly 100 is shown as having a longitudinal axis AX and including an end member, such as a top or bead plate 102, for example, that is adapted for securement on or along one of the structural components (e.g., upper structural component USC). It will be appreciated that the end member can be secured along the structural component in any suitable manner, such as, for example, by using one or more threaded mounting studs 104 that extend through corresponding mounting holes HLS in one of the associated structural components (e.g., upper structural component USC).

[0021] Gas spring 100 also includes an opposing end member, such as a piston 106, for example, that is longitudinally spaced from the other end member and that is adapted for securement on or along a different one of the structural components, such as lower structural component LSC, for example. Again, it will be appreciated that the end member can be operativeiy connected to or otherwise secured on or along the structural component in any suitable manner, such as is described below, for example.

[0022] Gas spring 100 also includes a flexible sleeve 108 (which could alternately take the form of a convoluted bellows) that is operativeiy connected between the end members and that at least partially defines a spring chamber 110 therebetween. A pressurized gas system (not shown) can be in fluid communication with spring chamber 110 in any suitable manner. For example, a passage 112 can extend through one of mounting studs 104 and in fluid communication with spring chamber 110 such that pressurized gas can be selectively transferred into and/or out of the spring chamber.

[0023] In the exemplary arrangement shown in FIG. 1 , flexible sleeve 108 includes a flexible wall 114 that extends between opposing first and second open ends 116 and 118. Flexible wall 114 includes an inside surface 120 that is in fluid communication with and at least partially defines spring chamber 110, and an outside surface 122 that abuttingly engages piston 106. First open end 116 can be secured on or along the end member in any manner suitable for forming a substantially fluid-tight seal therewith. For example, as shown in FIG. 1 , flexible sleeve 108 can include a mounting bead 124 formed along first open end 116 that can, optionally, include an annular reinforcement member, such as a bead wire 126, for example. Bead plate 102 can be secured along or across the first open end of the flexible sleeve, such as, for example, by capturing at least a portion of mounting bead 124 using a crimped edge connection 128.

[0024] Additionally, second open end 118 can be secured on or along the end member in any manner suitable for forming a substantially fluid-tight seal along or across the second open end. For example, as shown in FIG. 1 , flexible sleeve 108 can include a mounting bead 130 formed along second open end 118 that can, optionally, include an annular reinforcement member, such as a bead wire 132, for example. In the exemplary arrangement shown in FIG. 1 , an end closure 134 is at least partially received in second open end 118, and can be secured on or along piston 106 in a manner suitable for forming a substantially fluid-tight seal between the flexible wall and at least one of the end closure and the second end member. For example, end closure 134 can be adhered or otherwise attached to the open end (e.g., along a portion of inside surface 120 near second open end 118) such that a substantially fluid-tight seal is formed therebetween. Additionally, or in the alternative, end closure 134 can be secured on or along the end member (e.g., piston 106) such that at least a portion of mounting bead 130 is compressively captured between the end closure and the end member and such that a substantially fluid-tight seal can be formed therebetween. [0025] Additionally, it will be appreciated that flexible wall 114 can be formed in any suitable manner, such as by using one or more fabric-reinforced (or filament- reinforced), elastomeric plies or layers (not shown) and/or one or more un- reinforced, elastomeric plies or layers (not shown), for example. Typically, one or more fabric-reinforced, elastomeric plies and one or more un-reinforced, elastomeric plies will be used together and formed from a common elastomeric material, such as a synthetic rubber, a natural rubber or a thermoplastic elastomer. In other cases, however, a combination of two or more different materials or two or more grades of the same material could be used. In either case, the elastomeric material or materials from which the plies are formed will have certain material and/or mechanical properties, such as a hardness property, for example.

[0026] In the exemplary arrangement shown in FIG. 1 , piston 106 extends longitudinally between a first or upper end 136 and a second or lower end 138. First end 136 is adapted to receivingly engage second open end 118 of flexible sleeve 108, such as has been described above, for example. Second end 138 of piston 106 is adapted to abuttingly engage an associated structural component, such as lower structural component LSC, for example.

[0027] Piston 106 includes a piston body or shell 140 and can also, optionally, include one or more additional components and/or elements. The piston body has a first or outer side wall 142 that extends generally longitudinally between first and second ends 136 and 138. In use, a portion of flexible sleeve 108 forms a rolling- lobe 144 that is displaced along first side wall 142 as the gas spring assembly undergoes changes in overall height, such as, for example, may be due to variations in load conditions applied thereto, as is well understood by those of skill in the art. It will be recognized that a wide variety of shapes, profiles and/or configurations can and have been used in forming the first or outer side wall of gas spring pistons. As such, it will be appreciated that the profile of first side wall 142 is merely exemplary.

[0028] Piston 106 also includes a base plate 146 that is received within a lower, open end (not numbered) of piston body 140 and can be secured therein in any suitable manner, such as, for example, by welding the base plate and the piston body together, as indicated by all-around flowed-material joint FJ1. A central mounting hole 148 can, optionally, extend through base plate 146. Additionally, or in the alternative, outer mounting holes 150 can be provided, such as by being spaced radially outwardly from along axis AX. Weld nuts 152 can be secured, such as by flowed-material joints FJ2, for example, on base plate 146 adjacent outer mounting holes 150. Additionally, structural member holes HLS can optionally be provided, such as, for example, in alignment with the central mounting hole and/or the outer mounting holes for permitting the passage of a suitable fastener, for example.

[0029] First side wall 142 of piston body 140 extends generally longitudinally between a first or upper edge 154 along first end 136 and a second or lower peripheral edge 156 along second end 138. Piston body 140 also includes an end wall 158 that extends radially inwardly from along edge 154. End wall 158 includes a frustoconical portion 160, a bead-receiving groove 162, and a dish-shaped portion 164 that has a substantially-flat bottom wall 166 and is dimensioned to receivingly- engage at least a portion of end closure 134. It will be appreciated, however, that other configurations and/or arrangements could alternately be used. Additionally, a center column 168 can optionally be provided that extends generally longitudinally between end wall 158 of piston body 140 and base plate 146, and can be secured on or along the base plate in a suitable manner, such as by way of a flowed-material joint FJ3.

[0030] As mentioned above, the piston can be secured on or along an associated structural component, such as lower structural component LSC, for example, in any suitable manner and through the use of any suitable combination of components. Similarly, an end closure, such as end closure 134, for example, can, if provided, be secured on or along the piston in any suitable manner and through the use of any suitable combination of components. In the exemplary arrangement shown in FIG. 1 , a mounting stud 170 extends longitudinally between opposing ends 172 and 174. Mounting stud 170 extends through piston 106 such that end 172 projects into spring chamber 110 and end 174 projects outwardly beyond base plate 146.

[0031] A bumper mount 176 is disposed along end closure 134 within spring chamber 110. The bumper mount receives and operatively interengages, such as by way of a threaded connection, for example, mounting stud 170 along end 172 thereof. Bumper mount 176 and end closure 134 can be secured on or along piston 106 in any suitable manner. For example, mounting stud 170 can take the form of a length of threaded rod or, alternatively, can have a plurality of separately threaded portions, and a washer 178 and threaded nut 180 can threadably engage the mounting stud, such as is shown in FIG. 1 , for example. In this manner, as mounting stud 170 is tensioned by threaded nut 180, bumper mount 176 is drawn toward piston 106 and thereby secures end closure 134 on or along end wall 158 such that mounting bead 130 of flexible wall 154 is captured and retained therebetween. Additionally, end 174 of mounting stud 170 is shown in FIG. 1 as projecting longitudinally-outwardly beyond base plate 146 and through lower structural component LSC. A washer 182 and threaded nut 184 are shown as being received on the mounting stud and thereby securing piston 106 of gas spring assembly 100 on the lower structural member.

[0032] End closure 134 is shown as including a bottom wall 186 and a side wall 188 that projects in a generally axial direction from along bottom wall 186 toward and outer edge 190. An opening 192 (FIG. 5) extends through bottom wall 186 and can be approximately centrally disposed along the bottom wall such that mounting stud 170 can pass therethrough. As is shown in greater detail in FIG. 5, bumper mount 176 extends longitudinally between opposing ends 194 and 196 with end 194 disposed in spaced relation to bottom wall 186 and end 196 disposed toward the bottom wall of end closure 134. Bumper mount 176 includes an end wall 198 disposed along end 194 and an end wall 200 disposed along end 196. A side wall 202 extends generally longitudinally between ends 194 and 196 and a shoulder wall 204 extends radially inwardly into the bumper mount from along side wall 202 to form a projection 206 that is dimensioned to be at least partially received within opening 192 of end closure 134. Bumper mount 176 also includes a groove 208 that extends radially-inwardly into the bumper mount from along side wall 202. Groove 208 can be of any suitable size, shape and/or configuration operative to receive and retain an associated jounce bumper thereon. For example, as shown in FIGS. 1 and 5, groove 208 can include a first or upper portion 210 disposed toward end 194, a second or lower portion 212 that is spaced from the first portion, and a third or intermediate portion 214 that is disposed therebetween. In the exemplary arrangement shown in FIGS. 1 and 5, portion 210 has a curved shape or profile that functions as an end or shoulder of the groove, portion 214 is approximately cylindrical in shape and extend in approximate alignment with longitudinal axis AX, and portion 212 is tapered or frustoconical in shape and acts to transition from portion 214 to side wall 202. It will be appreciated, however, that such a construction is merely exemplary and that other suitable arrangements and/or configurations could alternately be used.

[0033] Gas spring assembly 100 also includes a jounce bumper 216 in accordance with the subject matter of the present disclosure. In the exemplary arrangement shown, jounce bumper 216 includes an outer side wall 218 and an inner side wall 220 that is disposed in radially inwardly-spaced relation to outer side wall 218 such that at least one cavity is defined between the inner and outer side walls. As identified in FIGS. 2 and 3, jounce bumper 216 can optionally include a plurality of connector walls 222 that extend between and operatively interconnect inner and outer side walls 218 and 220, and thereby at least partially define a plurality of cavities 224 disposed in circumferentially-spaced relation to one another along the inner and outer side walls and about axis AX.

[0034] Jounce bumper 216 can be formed from any suitable material or combination of materials. For example, jounce bumper 216 can be formed from a substantially rigid polymeric material, such as a fiber-reinforced polypropylene, a fiber-reinforced polyamide, or an un re info reed (i.e., relatively high-strength) thermoplastic (e.g., polyester, polyethylene, polyamide, polyether or any combination thereof), for example. Optionally, cavities 224 and/or other open portions or chambers of jounce bumper 216 can be filled with or otherwise include a quantity of one or more other materials (not shown) to modify or otherwise alter the axial and/or lateral deflection characteristics and/or performance of the jounce bumper. Such one or more other materials, if included, could be of any suitable type or kind, such as a quantity of a more-compliant material, a quantity of a more-rigid material and/or a second quantity of the same material from which the jounce bumper is made. [0035] As used herein, terms such as "rigid" and the like can refer to materials that have an elongation at the tensile limit of less than about 150 percent, and preferably have an elongation at the tensile limit of less than about 50 percent. Additionally, terms such as "compliant" and the like can refer to materials that have an elongation at the tensile limit of equal to or greater than about 150 percent, and preferably have an elongation at the tensile limit of greater than about 200 percent. Terms such as "yield stress" and the like can refer to the magnitude of force per unit area at which a material begins to plastically deform (i.e., to exceed its elastic tensile limit).

[0036] Outer and inner side walls 218 and 220 extend longitudinally between opposing ends 226 (FIG. 3) and 228 (FIG. 3) of jounce bumper 216. An end wall 230 extends between the outer and inner side walls along end 226 thereby at least partially forms a closed end of cavities 224. In the exemplary arrangement shown, cavities 224 are open along end 228. It will be appreciated, however, that other arrangements and/or configurations could alternately be used.

[0037] Inner side wall 220 extends peripherally about axis AX such that a cavity 232 is at least partially defined within jounce bumper 216. In the exemplary arrangement shown in FIGS 1-5, inner side wall 220 is shown as having a first or upper portion 220A and a second or lower portion 220B. Second portion 220B is shown as being radially-inwardly positioned relative to first portion 220A such that a transition portion 220C is disposed therebetween. It will be appreciated, however, that any other suitable arrangement and/or configuration could alternately be used. Jounce bumper 216 is positioned within spring chamber 110 and along the end member such bumper mount 176 is received within cavity 232. In a preferred arrangement, at least a portion of inner side wall 220 is disposed in abutting engagement with side wall 202 of the bumper mount. Such a configuration can be achieved in any suitable manner. As one example, second portion 220B of the inner side wall could be disposed in abutting engagement with the bumper mount. As another example, a plurality of ribs (which may also be referred to herein as crush ribs) 234 can be disposed in spaced relation to one another along second portion 220B of the inner side wall. In such case, ribs 234 can be of a suitable size, shape and arrangement such that a cross-sectional dimension D1 (FIG, 3) is formed that is less than a cross-sectional dimension D2 of side wall 202. In this manner, an interference fit, which is represented in FIG. 5 by overlapping hatch lines OVL, can be formed between the jounce bumper and the bumper mount.

[0038] Additionally, in known designs, the relative proportional size of the overall height and the overall width of a conventional bumper mount is often about the same. In such cases, this gives conventional bumper mounts a somewhat square cross-sectional shape. It has been determined, however, that improved resistance to deflection of the jounce bumper under lateral load conditions can be achieved by utilizing a bumper mount that has a substantially increased length over that of such known designs. One example of such a configuration is shown in FIGS. 1 and 5 in connection with bumper mount 176, which is shown as having a height (represented in FIG. 5 by dimension D3) that is substantially greater than the width of the bumper mount, which is represented by cross-sectional dimension D2 of side wall 202. In a preferred arrangement, the height (e.g., dimension D3) will be at least 1 .7 times (i.e., at least 70 percent greater than) the width (e.g., dimension D2) of the bumper mount. And, in a more preferred arrangement, the height (e.g., dimension D3) will be at least 1 .9 times (i.e., at least 90 percent greater than) the width (e.g., dimension D2) of the bumper mount.

[0039] Furthermore, in known designs, the relative proportional size of the bumper-engagement portion of a side wall is often less than the overall width of a conventional bumper mount. In general, the bumper-engagement portion of the side wall refers to the one or more (contiguous or non-contiguous) sections of the side wall that are dimensioned to receive and abuttingly engage the jounce bumper. In some cases, this bumper-engagement portion can extend between a feature of groove (e.g., groove 208) and the end closure (e.g., end closure 134) or another component or feature (e.g., shoulder wall 204), such as is represented in FIG. 5 by dimension D4, for example. In a preferred arrangement, the bumper-engagement portion (e.g., dimension D4) will be greater than the width of the bumper mount, such as, for example, being at least 1.2 times (i.e., at least 20 percent greater than) the width (e.g., dimension D2) of the bumper mount. In a more preferred arrangement, the bumper-engagement portion of side wall 202 (e.g., dimension D4) will be at least 1.4 times (i.e., at least 40 percent greater than) the width (e.g., dimension D2) of the bumper mount.

[0040] A jounce bumper in accordance with the subject matter of the present disclosure, such as jounce bumper 216, for example, can also include a plurality of retaining fingers or projections 236 that extend into cavity 232 from along inner side wall 220, such as, for example, is shown in FIGS. 1-5 as projecting from along second portion 220B adjacent transition portion 220C. In an installed condition of jounce bumper 216, retaining fingers 236 project radially-inwardly from along the inner side wall and operatively interengage bumper mount 176 such that the jounce bumper is axially retained thereon, such as by being restrained from axial displacement relative to the end member (e.g., piston assembly 106) along which the jounce bumper is secured. It will be appreciated that the retaining fingers can vary in circumferential size, circumferential position relative to one another (e.g., spacing between adjacent retaining fingers) and quantity depending upon a variety of factors that may vary from application to application. For example, a number of retaining fingers 236 within a range of from two (2) to fifty (50) retaining fingers could be used.

[0041] The plurality of retaining fingers of a jounce bumper in accordance with the subject matter of the present disclosure, such as plurality of retaining fingers 236, for example, differ from conventional arrangements in several respects. Like conventional retaining fingers, retaining fingers 236 include a first or inside surface 238 (FIG. 4) and a second or outside surface 240 (FIG. 4) opposite surface 238. However, retaining fingers 236 differ from conventional designs in that at least one of surfaces 238 and 240 has a radius of curvature in cross-section, such as is identified in FIG. 4, for example. In the exemplary arrangement shown in FIGS. 1-5, both surface 238 and surface 240 have a radius of curvature, such as are represented in FIG. 4 by reference dimensions 1 and R2. As a result, surfaces 238 and 240 will have a somewhat spherical shape, whereas conventional retaining fingers have straight or substantially non-curved profiles that result in a generally planar or, alternately, frustoconical shape. Reference dimensions R1 and R2 are illustrated in FIG. 4 as originating at a common center CTR. It will be recognized and appreciated, however, that surfaces 238 and 240 can alternately have different centers of curvature and/or radiuses of curvature without departing from the subject matter of the present disclosure.

[0042] As another example, plurality of retaining fingers 236 are believed to differ from conventional arrangements in that radius of curvature R1 of surface 238 extends approximately tangentially from along an inside surface 242 of second portion 220B of the inner side wall. In this manner, retaining fingers 236 can extend from along second portion 220 B of inner side wall 220 in an approximately axial direction before curving radially-inwardly for interengagement with the bumper mount.

[0043] As a further example, plurality of retaining fingers 236 are believed to differ from conventional arrangements in that the retaining fingers terminate at a distal or free end 244 that includes a corner 246 that is at least partially defined by an end wall 248 that is disposed in approximate alignment with axis AX (FIG. 3) and an end wall 250 that is disposed transverse to axis AX (FIG. 3) and end wall 248. Corner 246 can optionally include a radius. However, such a radius, if provided, is preferably of a relatively small dimension (e.g., having a shorter arc length than the length of either of end walls 248 and 250) such that a relatively sharp corner is formed. In this manner, corner 246 can deform into or otherwise conform with first portion 210 of groove 208 upon installation of the jounce bumper on the bumper mount. In this manner a positive interengagement between the retaining fingers of the jounce bumper and the retainment groove of the bumper mount can be achieved.

[0044] As used herein with reference to certain features, elements, components and/or structures, numerical ordinals (e.g., first, second, third, fourth, etc.) may be used to denote different singles of a plurality or otherwise identify certain features, elements, components and/or structures, and do not imply any order or sequence unless specifically defined by the claim language. Additionally, the terms "transverse," and the like, are to be broadly interpreted. As such, the terms "transverse," and the like, can include a wide range of relative angular orientations that include, but are not limited to, an approximately perpendicular angular orientation. Also, the terms "circumferential," "circumferentially," and the like, are to be broadly interpreted and can include, but are not limited to circular shapes and/or configurations. In this regard, the terms "circumferential," "circumferentially," and the like, can be synonymous with terms such as "peripheral," "peripherally," and the like.

[0045] Furthermore, the phrase "flowed-material joint" and the like are to be interpreted to include any joint or connection in which a liquid or otherwise flowable material (e.g., a melted metal or combination of melted metals) is deposited or otherwise presented between adjacent component parts and operative to form a fixed and substantially fluid-tight connection therebetween. Examples of processes that can be used to form such a flowed-material joint include, without limitation, welding processes, brazing processes and soldering processes. In such cases, one or more metal materials and/or alloys can be used to form such a flowed-material joint, in addition to any material from the component parts themselves. Another example of a process that can be used to form a flowed-material joint includes applying, depositing or otherwise presenting an adhesive between adjacent component parts that is operative to form a fixed and substantially fluid-tight connection therebetween. In such case, it will be appreciated that any suitable adhesive material or combination of materials can be used, such as one-part and/or two-part epoxies, for example.

[0046] Further still, the term "gas" is used herein to broadly refer to any gaseous or vaporous fluid. Most commonly, air is used as the working medium of gas spring devices, such as those described herein, as well as suspension systems and other components thereof. However, it will be understood that any suitable gaseous fluid could alternately be used.

[0047] It will be recognized that numerous different features and/or components are presented in the embodiments shown and described herein, and that no one embodiment may be specifically shown and described as including all such features and components. As such, it is to be understood that the subject matter of the present disclosure is intended to encompass any and all combinations of the different features and components that are shown and described herein, and, without limitation, that any suitable arrangement of features and components, in any combination, can be used. Thus it is to be distinctly understood claims directed to any such combination of features and/or components, whether or not specifically embodied herein, are intended to find support in the present disclosure.

[0048] Thus, while the subject matter of the present disclosure has been described with reference to the foregoing embodiments and considerable emphasis has been placed herein on the structures and structural interrelationships between the component parts of the embodiments disclosed, it will be appreciated that other embodiments can be made and that many changes can be made in the embodiments illustrated and described without departing from the principles hereof. Obviously, modifications and alterations will occur to others upon reading and understanding the preceding detailed description. Accordingly, it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the subject matter of the present disclosure and not as a limitation. As such, it is intended that the subject matter of the present disclosure be construed as including all such modifications and alterations.

Claims

CLAIMS:

1 . A jounce bumper dimensioned to receive an associated bumper mount, said jounce bumper comprising:

a side wall extending peripherally around a longitudinal axis and at least partially defining a bumper cavity; and,

a plurality of retaining fingers extending longitudinally from along said side wall and projecting radially-inwardly from said side wall into said bumper cavity, said plurality of retaining fingers disposed in spaced relation to one another around said longitudinal axis along said side wall, and said plurality of retaining fingers including at least one radius of curvature in cross section with said cross section taken from along a reference plane that contains said longitudinal axis.

2. A jounce bumper according to claim 1 , wherein said side wall and said plurality of retaining fingers are formed from a rigid polymeric material.

3. A jounce bumper according to either one of claims 1 and 2, wherein said plurality of retaining fingers extend from said side wall and terminate at a distal end including a corner formed from a first end wall disposed in approximate alignment with said longitudinal axis and a second end wall disposed transverse to said longitudinal axis.

4. A jounce bumper according to claim 3, wherein said first and second end walls have respective first and second lengths, and said plurality of retaining fingers include a radius formed along said corner with said radius having an arc length less than one of said first and second lengths.

5. A jounce bumper according to any one of claims 1-4, wherein said plurality of retaining fingers includes from 2 to 50 retaining fingers.

6. A jounce bumper according to any one of claims 1-5, wherein said plurality of retaining fingers include an inside surface facing toward said bumper cavity and an outside surface facing away from said bumper cavity with said at least one radius of curvature being formed along one of said inside surface and said outside surface.

7. A jounce bumper according to claim 6, wherein said at least one radius of curvature includes a first radius of curvature and a second radius of curvature with said first radius of curvature formed along said inside surface of said plurality of retaining fingers and said second radius of curvature formed along said outside surface of said plurality of retaining fingers.

8. A jounce bumper according to any one of claims 1 -7, wherein said side wall includes a plurality of ribs extending longitudinally along said side wall in communication with said bumper cavity.

9. A jounce bumper according to any one of claims 1-8, wherein said side wall is an inner side wall, and said jounce bumper further comprises an outer side wall spaced radially outwardly from said inner side wall and an end wall extending between and interconnecting said inner and outer side walls.

10. A jounce bumper according to claim 9 further comprising a plurality of connector walls extending between and operatively interconnecting said inner and outer side walls.

11. A gas spring assembly comprising:

a first end member;

a second end member spaced longitudinally from said first end member such that a longitudinal axis is defined therebetween;

a flexible wall extending peripherally around said longitudinal axis, said flexible wall secured along said first and second end members such that a spring chamber is at least partially defined therebetween; and, a jounce bumper according to any one of claims 1-10 disposed within said spring chamber and operatively connected to one of said first and second end members.

12. A gas spring assembly according to claim 11 further comprising a bumper mount secured along said first end member, said bumper mount including an outer side wall extending longitudinally into said spring chamber from along said first end member and a groove extending into said bumper mount from along said side wall, said outer side wall being dimensioned to compressively engage one of said side wall of said jounce bumper, and said groove dimensioned to receivingly engage said plurality of retaining fingers.

13. A gas spring assembly according to claim 12, wherein said bumper mount has a width dimension and a length dimension that is at least 70 percent greater than said width dimension.

14. A gas spring assembly according to claim 13, wherein said length dimension of said bumper mount is at least 90 percent greater than said width dimension.

15. A gas spring assembly according to any one of claims 12-14, wherein said bumper mount extends longitudinally between a proximal end disposed toward said first end member, a distal end disposed away from said first end member and a width dimension, and said groove is spaced away from said first end member toward said distal end a distance that is at least 20 percent greater than said width of said bumper mount.

16. A gas spring assembly according to claim 15, wherein said distance that said groove is spaced from said first end member is at least 40 percent greater than said width of said bumper mount. A kit comprising:

a jounce bumper according to any one of claims 1-10; and, a bumper mount as recited in any one of claims 12-16.