Axially restricting torsion spring using a tapered shaft

Abstract

Torsion spring and axial control device (200; 300; 400; 500; 600; 700) comprising: a shaft (220; 320; 420; 520; 620; 720) having a plurality of planar outer surfaces (236; 227; 326; 426) extending between a peripheral edge of a first shaft end (222; 322; 422) and a peripheral edge of a second shaft end (224; 324; 424), wherein a cross-sectional area of the first shaft end (222; 322; 422) is smaller than a cross-sectional area of the second shaft end (224; 324; 424), and a cross-sectional shape whose size gradually transitions between the first shaft end (222; 322; 422) and the second shaft end (224; 324; 424); a series of elongated elastomeric elements (230; 330; 430; 530; 630; 730), each elongated elastomeric element (230; 330; 430; 530; 630; 730) having a first elastomeric element end (232; 332; 432) and a second elastomeric element end (234; 334; 434), the first elastomeric element end (232; 332; 432) having a smaller cross-sectional area than the second elastomeric element end (234; 334; 434), the size of a cross-sectional shape of the elastomeric element (230; 330; 430; 530; 630; 730) gradually decreasing between the first elastomeric element end (232; 332; 432) and the second elastomer element end (234; 334; 434); and a tubular housing (210; 310; 410; 510; 610; 710) comprising a plurality of planar inner surfaces defining a housing interior, wherein adjacent edges of adjacent pairs of planar inner surfaces (216; 316; 416; 516; 616; 716) are joined at an angular transition (218; 318; 418; 518; 618; 718), wherein the shaft (220; 320; 420; 520; 620; 720) is inserted into the housing interior and each of the series of elongated elastomeric elements (230; 330; 430; 530; 630; 730) is arranged to contact a respective planar shaft outer surface (236; 227; 326; 426) and a pair of adjacent planar housing inner surfaces (216; 316; 416; 516; 616; 716), wherein the series of elongated elastomeric elements (230; 330; 430; 530; 630; 730) provides a torsional spring resistance force between the shaft (220; 320; 420; 520; 620; 720) and the housing (210; 310; 410; 510; 610; 710).

Description

Field of the invention

[0001] The present invention relates to a device for influencing torsional deflection and an axial force. More specifically, the device comprises a shaft held within a housing by a series of conical, elongated elastomer elements. The shaft is formed with a longitudinally trapezoidal outer surface whose contour is adapted to the surfaces of the series of conical, elongated elastomer elements. BACKGROUND OF THE INVENTIONReview of the prior art

[0002] Rubber torsion springs or dampers exert resistance in a torsional direction. Rubber torsion springs are commonly referred to as Neidhart springs. In a Neidhart spring, a shaft is held inside a tubular housing by a series of elongated elastomer elements. Each of the elements has a uniform cross-section along its length. Each of the elongated elastomer elements is held in direct contact between a planar outer surface of the shaft and two planar inner surfaces of the housing, with the two planar inner surfaces of the housing being joined by a common corner. When a torsional force is applied to the assembly during use, the shaft and housing are twisted relative to each other. The rotational difference compresses each of the elongated elastomer elements. The compression creates resistance to the applied torsional force.The resistance is provided in the form of a spring and a damper. Examples of such springs are given in the documents AT 186 071 B, US 2005 / 0 051 938 A1, US 6 588 788 B1, US 2 712 742 A, US 4 659 069 A, or DE 10 2006 033 119 A1.

[0003] The currently known design suffers from a significant limitation. The design has a uniform cross-section that extends the entire length of the device. The elements are typically manufactured using an extrusion process, cut to length, and then assembled by sliding the shaft and elongated elastomer elements into the housing. Although the currently known design controls torsional force by dampening the rotational movement and returning the device to a neutral configuration, the uniform cross-section is unable to control axial forces.

[0004] Therefore, there is a need for a device that controls torsional force by resisting and dampening rotational movement and returning the device to a neutral configuration, while additionally restricting axial movement. SUMMARY OF THE INVENTION

[0005] The present invention relates to a device that controls a torsional force by dampening a rotational movement and returning the device to a neutral configuration, while additionally restricting an axial movement.

[0006] In a first aspect of the present invention, a torsion spring and axial control device comprises: a shaft having a plurality of planar outer surfaces extending between a peripheral edge of a first shaft end and a peripheral edge of a second shaft end, a cross-sectional area of the first shaft end being smaller than a cross-sectional area of the second shaft end, and a cross-sectional shape whose size gradually transitions between the first shaft end and the second shaft end; a series of elongated elastomeric elements, each elongated elastomeric element having a first elastomeric element end and a second elastomeric element end, the first elastomeric element end having a smaller cross-sectional area than the second elastomeric element end, the size of a cross-sectional shape of the elastomeric element gradually transitioning between the first elastomeric element end and the second elastomeric element end; and a tubular housing comprising a plurality of planar inner surfaces defining a housing interior, wherein adjacent pairs of planar inner surfaces are joined at an angular junction, wherein the shaft is inserted into the housing interior and each of the series of elongated elastomeric elements is arranged to contact a respective planar shaft outer surface and a pair of adjacent planar housing inner surfaces, the series of elongated elastomeric elements exerting a torsional spring resistance force between the shaft and the housing.

[0007] In a second aspect of the present invention, the gradual transition of the cross-sectional shape of each of the elongate elastomeric elements is linear along its length.

[0008] In another aspect of the present invention, the gradual transition of the cross-sectional shape of the shaft is linear along its length.

[0009] In yet another aspect, the shaft is manufactured with an outer surface in the shape of a truncated pyramid.

[0010] In yet another aspect, the tubular housing is made with a uniform cross-section along its length.

[0011] In yet another aspect, the shaft is made of a rigid material.

[0012] In yet another aspect, the shaft is made of a compliant material.

[0013] In another aspect, the shaft is made of a compliant material laminated to the outer surface of a rigid material.

[0014] In yet another aspect, the shaft is manufactured with a twisted configuration.

[0015] In yet another aspect, each of the planar outer surfaces of the shaft has equal transverse dimensions, and each of the planar housing inner surfaces has equal transverse dimensions.

[0016] In yet another aspect, the shaft includes four planar outer surfaces, and the housing includes four planar inner surfaces.

[0017] In yet another aspect, each of the four planar outer surfaces of the shaft has equal transverse dimensions, and each of the four planar housing inner surfaces has equal transverse dimensions.

[0018] In yet another aspect, the shaft includes three planar outer surfaces, and the housing includes three planar inner surfaces.

[0019] In yet another aspect, the shaft includes five planar outer surfaces, and the housing includes five planar inner surfaces.

[0020] In yet another aspect, the shaft includes six planar outer surfaces, and the housing includes six planar inner surfaces.

[0021] In yet another aspect, the shaft comprises n planar outer surfaces and the housing comprises n planar inner surfaces, where n is selected from a group of numbers of surfaces comprising three, four, five, six, and eight.

[0022] In another aspect, a first rotationally and axially controlling spring is aligned near a second rotationally and axially controlling spring with equal sized housing ends arranged side by side.

[0023] In yet another aspect, the rotationally and axially controlling spring further comprises an axial retention element. The axial retention element is preferably located adjacent a smaller housing end.

[0024] In yet another aspect, the shaft is configured in elevation with an hourglass shape. The hourglass shape is formed by joining the narrower ends of two frusto-polygonal elements, with the longitudinal axes of the frusto-polygonal elements arranged parallel to each other.

[0025] In an alternative embodiment, the rotationally and axially controlling spring may include a shaft configured with an hourglass-shaped side profile and a series of elongated elastomeric elements having a double frustoconical shape. The double frustoconical shape is formed by joining the wider ends of two frustoconical elements, the longitudinal axes of the frustoconical elements being non-parallel to each other, the double frustoconical shape forming a triangular profile having a linear edge extending a length between the first elongated elastomeric element end and the second elongated elastomeric element end, and a "V"-shaped opposite edge.

[0026] In yet another aspect, tapered components of the rotationally and axially controlling spring provide an axial control function that restricts movement of the shaft to a single axial direction, wherein the single axial direction extends from a larger cross-sectional area of the elongated elastomeric elements to a smaller cross-sectional area of the elongated elastomeric elements.

[0027] In yet another aspect, tapered components of the rotationally and axially controlling spring provide an axial control function that restricts movement of the elongated elastomeric elements to a single axial direction, wherein the single axial direction is from a larger shaft cross-sectional area to a smaller shaft cross-sectional area.

[0028] In yet another aspect, tapered components of the rotational and axial controlling spring provide an axial control function that restricts movement of the shaft and the elongated elastomeric elements in both axial directions.

[0029] The rotational and axial control spring offers several advantages over currently available rubber torsion springs. Tapering the series of elongated elastomer elements and the respective tubular housing limits the axial movement of a mating element in a first direction. By integrating a pair of oppositely aligned rotational and axial control springs into an assembly, the pair of rotational and axial control springs limits the axial movement of the mating element in two directions. The elongated elastomer elements can be designed to optimize damping and spring rates by exploiting the variation in cross-sectional shape along their length.

[0030] Another advantage over currently available rubber torsion springs is that the tapered configuration reduces stress under torsional and axial loads.

[0031] Those skilled in the art will be able to better understand and appreciate these and other features, aspects, and advantages of the invention from the following written specification, claims, and accompanying drawings which follow. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] To gain a more complete understanding of the nature of the present invention, reference should be made to the accompanying drawings in which: Fig. 1 shows an isometric view of an exemplary rubber torsion spring according to the prior art; Fig. 2 shows an end elevation of the rubber torsion spring, which is first Fig. 1, the illustration showing the rubber torsion spring in a normal, relaxed state; Fig. 3 shows an end elevation of the rubber torsion spring, which is first Fig. 1, the illustration showing the rubber torsion spring under the influence of a torsional force; Fig. Figure 4 shows an isometric view of an exemplary rotational and axial controlling spring; Fig. Figure 5 shows an end elevation of the rotational and axial controlling spring, which is first Fig. 4, the illustration showing the rubber torsion spring in a normal, relaxed state; Fig. Figure 6 shows an end elevation of the rotational and axial controlling spring, which is first Fig. 4, the illustration showing a wave with a twisted shape in a normal, ‘relaxed’ state; Fig. Figure 7 shows an isometric exploded assembly view of the first Fig. 4 shown rotational and axial controlling spring; Fig. Figure 8 shows a side elevation of a pair of rotational and axial controlling springs, which are first Fig.4, with the pair oriented so that like larger elastomeric ends / smaller shaft ends are arranged side by side; Fig. Figure 9 shows a side elevation of a modified rotational and axial controlling spring first described in Fig. 4, with an axial retaining element added to the illustration; Fig. 10 shows a side elevation of an alternative embodiment of a rotationally and axially controlling spring, the rotationally and axially controlling spring comprising a shaft having an hourglass shape and a series of elongated elastomeric elements having a biconic, angled truncated shape; Fig. 11 shows an end elevation of the rubber torsion spring, which is first Fig. 10, the illustration showing the rubber torsion spring in a normal, relaxed state; Fig.12 shows a side elevation of another alternative embodiment of a rotationally and axially controlling spring, the rotationally and axially controlling spring comprising a pair of frusto-pyramidal shafts pointing in opposite directions, the pair of shafts engaging a series of biconic, angled, frusto-shaped, elongated elastomeric elements; Fig. 13 shows an end elevation of another exemplary rubber torsion spring wherein the shaft includes three planar outer surfaces and the housing includes three planar inner surfaces; Fig. 14 shows an end elevation of another exemplary rubber torsion spring wherein the shaft includes five planar outer surfaces and the housing includes five planar inner surfaces; and Fig. 15 shows an end elevation of another exemplary rubber torsion spring wherein the shaft includes six planar outer surfaces and the housing includes six planar inner surfaces.

[0033] Like reference numerals indicate like parts throughout the different views of the drawings. DETAILED DESCRIPTION OF THE INVENTION

[0034] The following detailed description is merely exemplary in nature and is not intended to limit the described embodiments or the applications and uses of the described embodiments. As used herein, the words "exemplary" or "illustrative" mean "serving as an example, exemplary instance, or illustration." An implementation described herein as "exemplary" or "illustrative" should not necessarily be construed as preferred or advantageous over other implementations. All implementations described below are exemplary implementations intended to enable those skilled in the art to make or use embodiments of the disclosure and are not intended to limit the scope of the disclosure as defined by the claims.For the purpose of description herein, the terms "upper", "lower", "left", "rear", "right", "front", "vertical", "horizontal" and their derivatives refer to the invention as described in . Fig.1. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the foregoing prior art, background, summary, or the following detailed description. It is further to be understood that the specific devices and processes illustrated in the accompanying drawings and described in the following specification are merely exemplary embodiments of the inventive concepts defined in the appended claims. Accordingly, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be regarded in a limiting sense unless the claims expressly state otherwise.

[0035] An exemplary rubber torsion spring 100 according to the known prior art is shown in the Fig.1 to 3. The rubber torsion spring 100 integrates a tubular housing 110, a shaft 120, and a series of elongated elastomeric elements 130 into a single assembly. The tubular housing 110 has a tubular cross-section forming an equilateral convex polygonal shape extending between a first housing end 112 and a second housing end 114. The tubular housing 110 has a uniform cross-section extending along its length. Due to the uniform cross-sectional area and low manufacturing cost, the tubular housing 110 is typically manufactured using an extrusion process. The tubular housing 110 is preferably fabricated from a rigid material, such as a plastic, a metal, a composite material, and the like.The interior of the tubular housing 110 defines a plurality of housing interior planar surfaces 116, with mating edges of each pair of adjacent housing interior planar surfaces 116 forming a housing interior angle transition 118. The plurality of housing interior planar surfaces 116 define a perimeter of a housing interior volume. The exemplary embodiment includes four (4) equally sized housing interior planar surfaces 116.

[0036] The shaft 120 has a cross-section forming an equilateral convex polygon shape extending between a first shaft end surface 122 and a second shaft end surface 124. The shape of the shaft cross-section is similar to the cross-sectional shape of the housing. An exterior surface of the shaft 120 is defined by: a first shaft end surface 122 located at a first longitudinal end, a second shaft end surface 124 located at a second, opposite longitudinal end, and a plurality of shaft exterior longitudinal surfaces 126 extending therebetween. The number of shaft exterior longitudinal surfaces 126 is equal to the number of housing interior planar surfaces 116. The shaft 120 has a uniform cross-section extending along its length. Like the tubular housing 110, the shaft 120 is typically manufactured using an extrusion process due to the uniform cross-sectional area and low manufacturing cost.The shaft 120 is typically made of a compliant material. The shaft 120 is inserted into the interior of the tubular housing 110. The shaft 120 is rotated, with each shaft outer longitudinal surface 126 aligned with a respective housing inner angular transition 118.

[0037] Each elongated elastomeric member 130 has a uniform cross-section extending along a length defined between a first elongated elastomeric member end surface 132 and a second elongated elastomeric member end surface 134. The exposed surface extending between the first elongated elastomeric member end surface 132 and the second elongated elastomeric member end surface 134 is referred to as an elongated member outer surface 136. The elongated elastomeric member 130 is made from a rubber or other resilient material. Like the tubular housing 110 and shaft 120, the elongated elastomeric member 130 is typically manufactured using an extrusion process due to its uniform cross-sectional area and low manufacturing cost. The elongated elastomeric member 130 can be manufactured with a circular or elliptical cross-sectional shape.

[0038] During use, the outer surface 136 of each elongated elastomeric element 130 engages the respective shaft outer longitudinal surface 126 and a pair of respective housing inner planar surfaces 116. The three contact points prevent the shaft 120 from rotating relative to the tubular housing 110 when a torsional force is applied in a direction of rotational movement 150. The shaft 120 deforms, forming a second shaft end surface 124 in the region that engages the respective elongated elastomeric element 130. As the rotational movement 150 is performed, the compliance of the elongated elastomeric element 130 allows incremental rotation of the shaft 120 relative to the tubular housing 110. As the movement continues, the elongated elastomeric element 130 is compressed, with the compression of the elongated elastomeric element 130 increasing the resistance of the rotational movement 150.Additionally, the rotational movement 150 uses each elongated elastomer element 130 as a wedge, further increasing the resistance to the rotational movement 150. When the torsional force is removed, the compliance of each row of elongated elastomer elements 130 returns the shaft 120 to a natural, relaxed position.

[0039] In an alternative embodiment, the rubber torsion spring 100 may include a twisted shaft 121 having an elastomeric shaft engagement deformation 129 for engaging each elongated elastomeric element 130. The twisted section of the twisted shaft 121 enhances the interaction between the twisted shaft 121 and the elongated elastomeric element 130. Furthermore, the shape of the twisted shaft 121 increases the rotational resistance of the twisted shaft 121 within the rubber torsion spring 100.

[0040] One limitation of the rubber torsion spring 100 is its freedom of movement in an axial direction, identified as axial movement 140. The uniform cross-section allows for axial movement of the various components and / or other complementary equipment.

[0041] An exemplary rotational and axial controlling spring, designated by the reference numeral 200, is shown in the Fig. 4 to 7. The rotational and axial control spring 200 includes elements with a tapered shape that perform an axial control function.

[0042] The rotational and axial control spring 200 integrates a tubular housing 210, a shaft 220, and a series of elongated elastomeric elements 230 into a single assembly. The tubular housing 210 is formed with a tubular cross-section forming an equilateral convex polygon shape extending between a first housing end 212 and a second housing end 214. The tubular housing 210 has a uniform cross-section extending along its length. Due to the uniform cross-sectional area and low manufacturing cost, the tubular housing 210 is typically manufactured using an extrusion process. The tubular housing 210 is preferably fabricated from a rigid material, such as plastic, metal, a composite material, and the like.The interior of the tubular housing 210 defines a plurality of housing interior planar surfaces 216, with mating edges of each pair of adjacent housing interior planar surfaces 216 forming a housing interior angle transition 218. The plurality of housing interior planar surfaces 216 define a perimeter of a housing interior volume. The exemplary embodiment includes four (4) equally sized housing interior planar surfaces 216.

[0043] The shaft 220 has an outer surface that forms a tubular truncated pyramid shape. A first shaft end surface 222 defines a first end of the shaft 220, and a second shaft end surface 224 defines a second end of the shaft 220. The first shaft end surface 222 has a smaller cross-sectional area compared to the cross-sectional area of the second shaft end surface 224, and the size of the cross-sectional shape gradually transitions between the first shaft end surface 222 and the second shaft end surface 224, forming the truncated pyramid shape. The cross-sectional shape of the shaft is similar to the cross-sectional shape of the housing. A series of shaft outer longitudinal surfaces 226 extend between the first shaft end surface 222 and the second shaft end surface 224 of the shaft 220. The number of shaft outer longitudinal surfaces 226 is equal to the number of housing inner planar surfaces 216.Shaft 220 may be manufactured using any suitable manufacturing process, including molding, machining, casting, and the like. Shaft 220 may be made from a compliant material, a rigid material, or a rigid material coated with a compliant material, such as a laminated elastomeric coating 228 applied to a rigid core.

[0044] Each elongated elastomeric member 230 is shaped into a truncated cone. A first end surface 232 of an elongated elastomeric member defines a first end of the elongated elastomeric member 230, and a second end surface 234 of an elongated elastomeric member defines a second end of the elongated elastomeric member 230, wherein the first end surface 232 of an elongated elastomeric member is smaller than the second end surface 234 of an elongated elastomeric member. An outer surface 236 of an elongated member extends between a peripheral edge of the first end surface 232 of an elongated elastomeric member and a peripheral edge of the second end surface 234 of an elongated elastomeric member. The exemplary elongated elastomeric member 230 has a rounded cross-sectional shape, wherein the cross-sectional shape may be elliptical, circular, and the like.It is understood that the cross-sectional shape may also be triangular or may consist of a combination of a corner segment and a rounded segment. The elongated elastomeric element 230 preferably has a circular or elliptical cross-sectional shape. The sidewall of the elongated elastomeric element 230 is formed with a gradual transition in cross-sectional shape extending between a peripheral edge of the first end surface 232 of an elongated elastomeric element and a peripheral edge of the second end surface 234 of an elongated elastomeric element. The preferred transition shape of the cross-sectional shape along a length of the elongated elastomeric element 230 between the first end surface 232 of an elongated elastomeric element and the second end surface 234 of an elongated elastomeric element is linear.It is also understood that the transition between the first end surface 232 of an elongated elastomeric member and the second end surface 234 of an elongated elastomeric member may be of any suitable shape, including an arcuate section, a series of rings, fingers, and the like. When the elongated elastomeric member 230 is positioned to contact the shaft outer longitudinal surface 226, the angle formed by a distal surface of the frustoconical shape of the elongated elastomeric member 230 coincides with the angle defined by the housing inner planar surface 216 of the tubular housing 210.

[0045] Each elongated elastomer element 230 can be optimized to suit the target application. The hardness, or modulus, of the elastomer can be varied to obtain different torsional and axial resistances, or spring rates, within the same design envelope. A low-modulus rubber would produce a soft spring, while a high-modulus rubber would produce a very stiff spring. For example, a typical hardness would be 20 Shore A Durometer to 60 Shore D Durometer. A corresponding compression or shear modulus range could be 20 psi to 1000 psi. The material for the elongated elastomer elements 230 can be selected from any variety of rubber, plastic, or other polymer materials to obtain optimal properties of spring rate, fluid and environmental resistance, and the like.The elongated elastomeric member 230 is made from any elastomeric or elastic material, including natural rubber, synthetic rubber, nitrile, polyurethane, EPDM, silicone, fluoroelastomer, epichlorohydrin, SBR, polybutadiene, neoprene, thermoplastic elastomers, elastin, and the like.

[0046] The assembly of the rotational and axial controlling spring 200 is best shown in the exploded assembly view shown in Fig.7. The rotational and axial controlling spring 200 is assembled by inserting the shaft 220 into an inner section of the tubular housing 210. The shaft 220 is rotated, aligning each shaft outer longitudinal surface 226 with a respective housing inner angular transition 218. The rotational and axial controlling spring 200 includes an elongated elastomeric element 230 for each shaft outer longitudinal surface 226 of the shaft 220. A single elongated elastomeric element 230 is installed to contact a respective shaft outer longitudinal surface 226 and a pair of adjacent housing inner planar surfaces 216 for each of the shaft outer longitudinal surfaces 226.

[0047] During use, each outer surface 236 of the respective elongated elastomeric member 230 engages the respective shaft outer longitudinal surface 226 and a pair of respective housing inner planar surfaces 116. The three points of contact prevent rotation of the shaft 220 relative to the tubular housing 210 when a torsional force is applied in a direction of rotational movement 250. As the rotational movement 250 is performed, the compliance of the elongated elastomeric member 230 allows incremental rotation of the shaft 220 relative to the tubular housing 210. As the movement continues, the elongated elastomeric member 230 is compressed, with the compression of the elongated elastomeric member 230 increasing the resistance to the rotational movement 250. In addition, the rotary motion 250 utilizes each elongated elastomer element 230 as a wedge, so that the resistance to the rotary motion 250 is further enhanced.When the torsional force is removed, the compliance of each row of elongated elastomer elements 230 returns the shaft 220 to a natural, relaxed position.

[0048] In an alternative embodiment, the rotational and axial control spring 200 may include a twisted shaft 221 having an elastomeric shaft engagement deformation 229 for engaging each elongated elastomeric member 230. The twisted section of the twisted shaft 221 enhances the interaction between the twisted shaft 221 and the elongated elastomeric member 230. Furthermore, the shape of the twisted shaft 221 increases the rotational resistance of the twisted shaft 221 within the rotational and axial control spring 200. It can be seen that twisted cams are limited, with the torsional resistance differing relative to the direction of rotation; more specifically, the torsional resistance differs between clockwise and counterclockwise rotation. Furthermore, the maximum rotation is also limited differently between clockwise and counterclockwise rotation.

[0049] A unique advantage of the rotationally and axially controlling spring 200 over the rubber torsion spring 100 is the tapered shape. The truncated pyramid shape of the shaft 220 limits the axial movement 240 of the elongated elastomeric elements 230 to a direction from the larger first shaft end surface 222 to the smaller second shaft end surface 224. Similarly, the frustoconical shape of each elongated elastomeric element 230 limits the axial movement 240 of the shaft 220 to a direction from the larger second end surface 234 of an elongated elastomeric element to the smaller first end surface 232 of an elongated elastomeric element. The restriction prevents the shaft 220 and / or any of the elongated elastomeric elements 230 from moving axially or migrating out of the inner chamber of the tubular housing 210 during an application in which a combination of torsional load and axial load is applied.Another advantage is the ability to shape each of the elongated elastomer elements 230 to fine-tune the damping coefficient and spring rate. The thickness, density of the material, shape of the sidewall 236, and the like can fine-tune the properties of the elongated elastomer element 230.

[0050] By arranging each of a pair of rotationally and axially controlling spring subassemblies 202, 204 in such a manner that like ends abut each other along the longitudinal axis, as in Fig.8, the pair 202, 204 restricts the movement of the internal components along the axial movement 240. In a configuration where the pair of rotational and axially controlling spring subassemblies 202, 204 are arranged such that the second housing ends 214 abut each other (as illustrated), the configuration restricts the axial movement 240 of the series of elongated elastomeric elements 230 in both axial directions and prevents the pair of shafts 220 from moving relative to each other. In a configuration where the pair of rotational and axially controlling spring subassemblies 202, 204 are arranged such that the first housing ends 212 abut each other, the configuration restricts the axial movement 240 of the pair of shafts 220 in both axial directions and prevents the series of elongated elastomeric elements 230 from moving relative to each other.It should be understood that the pair of rotational and axial control springs 200 may be interconnected or integrated into a single unit. An integrated unit would interconnect the pair of tubular housings 210 and the pair of shafts 220.

[0051] An optional axial retaining element 242 can be integrated into the rotational and axial controlling spring 200, as shown in Fig. 9 to improve the axial control of the elongated elastomeric elements 230 when disposed near the smaller second shaft end surface 224 (as illustrated). The optional axial retaining element 242 can be incorporated into the rotationally and axially controlling spring 200 to improve the axial control of the shaft 220 when disposed near the larger first shaft end surface 222.

[0052] It is understood that by combining tapered elements, the designer can control the axial movement 240 of one or more components in one or more axial directions. Various exemplary embodiments for accomplishing this function are presented below.

[0053] A modified version of the present invention may be provided by combining the shapes of the pair of rotationally and axially controlling spring subassemblies 202, 204 to form a rotationally and axially controlling spring 300 as shown in the Fig. 10 and Fig.11. The rotationally and axially controlling spring 300 can be described as being divided into a first spring segment 302 and a second spring segment 304. The shaft 320 has an hourglass shape by joining two frusto-pyramidal segments at a central shaft throat 323. Two frusto-pyramidal segments of the shaft 320 are joined together by aligning their longitudinal axes. Each of the elongated elastomeric elements 330 of a series of elongated elastomeric elements 330 is formed by joining two frusto-conical segments at a central section 333 of elastomeric elements with an offset angle between the longitudinal axes. The offset angle segments the outer surface 336 of an elongated element into a linear housing contact surface segment 337 and a triangular shaft contact surface segment 338.The linear housing contact surface segment 337 engages a pair of adjacent housing-interior planar surfaces 316, and the triangular shaft contact surface segment 338 engages an exterior shaft longitudinal surface 326 of the shaft 320. The interface between the hourglass-shaped shaft 320 and the angled biconic elongated elastomeric element 330 prevents the shaft 320 and the elongated elastomeric elements 330 from any axial movement 340 in any direction.

[0054] A further modified version of the present invention may be provided by combining the shapes of the pair of rotationally and axially controlling spring subassemblies 202, 204 to form a rotationally and axially controlling spring 400 as shown in Fig.12. The rotational and axial controlling spring 400 is similar to the rotational and axial controlling spring 300, with the rotational and axial controlling spring 400 including a pair of truncated pyramid-shaped shafts 420, while the rotational and axial controlling spring 300 including a single hourglass-shaped shaft 320. Like features of the rotational and axial controlling spring 400 and the rotational and axial controlling spring 300 are numbered alike except preceded by the numeral "4." The rotational and axial controlling spring 400 is assembled by inserting each row of elongated elastomeric elements 430 into the interior of the tubular housing 410. Each shaft 420 is then pushed into the interior of the tubular housing 410.A linear housing contact surface segment 437 engages a pair of adjacent housing-interior planar surfaces 416, and the triangular shaft contact surface segment 438 engages a shaft-outside longitudinal surface 426 of the shaft 420. The interface between the pair of shafts 420 and the angled biconic elongated elastomeric element 430 restricts each of the series of elongated elastomeric elements 330 from any axial movement 340 in any direction and prevents the shaft 320 from migrating inward toward a center of the rotationally and axially controlling spring 400.

[0055] It should be understood that the rotationally and axially controlling spring may also be provided in other configurations. One configuration utilizes a shaft similar in shape to shaft 320 and a series of eight (8) elongated elastomeric elements 230. The elongated elastomeric elements 230 would be arranged such that the wider ends of the second end surface 234 of the elongated elastomeric elements are placed against each other and aligned to contact the shaft outer longitudinal surface 326. The subassembly is then slid into the tubular housing 210. The hourglass shape of the shaft 320 holds each of the series of eight (8) elongated elastomeric elements 230 in axial position.

[0056] Although the exemplary rotational and axial controlling springs 200, 300, 400 are configured with four (4) equally sized planar surfaces 216, 316, 416 inside the housing, it is understood that the rotational and axial controlling spring may also be configured with three (3) or more equally sized planar surfaces 216, 316, 416 inside the housing, wherein one skilled in the art would recognize that as the number of sides increases, the allowable angle of rotation becomes smaller. Various examples are shown in the Fig. 13 to 15 shown.

[0057] A triangular rotational and axial controlling spring 500 is in Fig.13. The triangular rotational and axial controlling spring 500 is similar to the rotational and axial controlling spring 200, with the difference being the number of sides. The triangular rotational and axial controlling spring 500 has three (3) equal sides, and the rotational and axial controlling spring 200 has four (4) equal sides. Like features of the triangular rotational and axial controlling spring 500 and the rotational and axial controlling spring 200 have the same reference numerals except that they are preceded by the numeral "5." The triangular rotational and axial controlling spring 500 would be configured to have the same tapered features of the rotational and axial controlling spring 200 previously described.

[0058] A pentagonal rotational and axial controlling spring 600 is in Fig.14. The pentagonal rotational and axial controlling spring 600 is similar to the rotational and axial controlling spring 200, with the difference being the number of sides. The pentagonal rotational and axial controlling spring 600 has five (5) equal sides, and the rotational and axial controlling spring 200 has four (4) equal sides. Like features of the hexagonal rotational and axial controlling spring 600 and the rotational and axial controlling spring 200 have the same reference numerals except that they are preceded by the numeral "6." The pentagonal rotational and axial controlling spring 600 would be configured to have the same tapered features of the rotational and axial controlling spring 200 previously described.

[0059] A hexagonal rotational and axial controlling spring 700 is in Fig.15. The hexagonal rotational and axial controlling spring 700 is similar to the rotational and axial controlling spring 200, with the difference being the number of sides. The hexagonal rotational and axial controlling spring 700 has six (6) equal sides, and the rotational and axial controlling spring 200 has four (4) equal sides. Like features of the hexagonal rotational and axial controlling spring 700 and the rotational and axial controlling spring 200 have the same reference numerals except that they are preceded by the numeral "7." The hexagonal rotational and axial controlling spring 700 would be configured to have the same tapered features of the rotational and axial controlling spring 200 previously described.

[0060] Although the exemplary embodiments depict rotationally and axially controlling springs with three (3), four (4), five (5), and six (6) sides, it should be understood that the rotationally and axially controlling spring may also be configured with seven (7), eight (8), nine (9), ten (10), or more sides. The greater the number of sides, the lower the maximum torsional rotation.The rotation is limited to a maximum deflection of one-half turn from the starting position (where the shaft outer side longitudinal surface 226 is aligned with the housing inner angular transition 218) toward a second indexed starting position (where the shaft outer side longitudinal surface 226 is aligned with an adjacent housing inner angular transition 218); or in other words, the rotation of the shaft 220 from a starting position where the shaft outer side longitudinal surface 226 is aligned with the housing inner angular transition 218 to a position where the shaft outer side longitudinal surface 226 coincides with a facing housing inner planar surface 216. The following table shows a maximum torsional rotation relative to the number of shaft outer side longitudinal surfaces 226. Cross-sectional shape Number of pages Maximum degree of rotation Triangular 3 60 degrees Square 4 45 degrees Pentagon 5 36 degrees hexagon 6 30 degrees TABLE: ROTATION BASED ON THE NUMBER OF SIDES OF THE SPRING

[0061] The exemplary embodiment shows a rotationally and axially controlling spring 200 that includes an elongated elastomeric element 230 made of an elastomeric material. It should be understood that the elongated elastomeric element 230 could also be made of a rigid material, or the elastomeric material could be laminated to a rigid material. The springing and damping functions would be performed by a shaft 210 made of an elastomeric material.

[0062] Since many modifications, variations, and changes in detail may be made to the described preferred embodiments of the invention, it is intended that all matters described above and shown in the accompanying drawings be considered as illustrative and not to be interpreted in a limiting sense. The scope of the invention should therefore be determined by reference to the appended claims and their legal equivalents. LIST OF REFERENCE NUMBERS 100 rubber torsion springs 110 tubular housing 112 first housing end 114 second housing end 116 housing inner planar surface 118 housing inner angle transition 120 wave 121 twisted shaft 122 first shaft end face 124 second shaft end face 126 Shaft outer side longitudinal surface 127 twisted shaft outer side longitudinal surface 129 Shaft with twisted configuration 130 elongated elastomer element 132 first end face of an elongated elastomer element 134 second end face of an elongated elastomer element 136 Outer surface of an elongated element 140 axial movement 150 rotational movement 200 rotational and axial controlling spring 202 first spring segment 204 second spring segment 210 tubular housing 212 first housing end 214 second housing end 216 housing inner planar surface 218 housing inner angle transition 220 wave 221 twisted shaft 222 first shaft end face 224 second shaft end face 226 Shaft outer side longitudinal surface 227 twisted shaft outer side longitudinal surface 228 laminated elastomeric coating 229 Shaft with twisted configuration 230 elongated elastomer element 232 first end face of an elongated elastomer element 234 second end face of an elongated elastomer element 236 Outer surface of an elongated element 240 axial movement 242 axial retaining element 250 rotation 300 rotational and axial controlling spring 302 first spring segment 304 second spring segment 310 tubular housing 312 first housing end 314 second housing end 316 housing inner planar surface 318 housing inner angle transition 320 wave 322 first shaft end face 323 central wave constriction 324 second shaft end face 326 Shaft outer side longitudinal surface 330 elongated elastomer element 332 first end face of an elongated elastomer element 333 Middle section of an elongated elastomer element 334 second end face of an elongated elastomer element 336 Outer surface of an elongated element 337 linear housing contact surface segment 338 triangular shaft contact surface segment 340 axial movement 342 axial retaining element 350 rotation 400 rotational and axial controlling spring 402 first spring segment 404 second spring segment 410 tubular housing 412 first housing end 414 second housing end 416 housing inner planar surface 418 housing inner angle transition 420 wave 422 first shaft end face 423 central wave constriction 424 second shaft end face 426 Shaft outer side longitudinal surface 430 elongated elastomer element 432 first end face of an elongated elastomer element 433 Middle section of an elongated elastomer element 434 second end face of an elongated elastomer element 436 Outer surface of an elongated element 437 linear housing contact surface segment 438 triangular shaft contact surface segment 440 axial movement 442 axial retaining element 500 triangular rotational and axial controlling spring 510 tubular triangular housing 512 housing end 516 housing inner planar surface 518 housing inner angle transition 520 wave 530 elongated elastomer element 600 pentagonal rotational and axial controlling spring 610 tubular pentagonal case 612 housing end 616 housing inner planar surface 618 housing inner angle transition 620 wave 630 elongated elastomer element 700 hexagonal rotational and axial controlling spring 710 tubular hexagonal case 712 housing end 716 housing inner planar surface 718 housing inner angle transition 720 wave 730 elongated elastomer element

Claims

[1] Torsion spring and axial control device (200; 300; 400; 500; 600; 700) comprising: a shaft (220; 320; 420; 520; 620; 720) having a plurality of planar outer surfaces (236; 227; 326; 426) extending between a peripheral edge of a first shaft end (222; 322; 422) and a peripheral edge of a second shaft end (224; 324; 424), wherein a cross-sectional area of the first shaft end (222; 322; 422) is smaller than a cross-sectional area of the second shaft end (224; 324; 424), and a cross-sectional shape whose size gradually transitions between the first shaft end (222; 322; 422) and the second shaft end (224; 324; 424); a series of elongated elastomeric elements (230; 330; 430; 530; 630; 730), each elongated elastomeric element (230; 330; 430; 530; 630; 730) having a first elastomeric element end (232; 332; 432) and a second elastomeric element end (234; 334; 434), the first elastomeric element end (232; 332; 432) having a smaller cross-sectional area than the second elastomeric element end (234; 334; 434), the size of a cross-sectional shape of the elastomeric element (230; 330; 430; 530; 630; 730) gradually decreasing between the first elastomeric element end (232; 332; 432) and the second elastomer element end (234; 334; 434); and a tubular housing (210; 310; 410; 510; 610; 710) comprising a plurality of planar inner surfaces defining a housing interior, wherein adjacent edges of adjacent pairs of planar inner surfaces (216; 316; 416; 516; 616; 716) are joined at an angular transition (218; 318; 418; 518; 618; 718), wherein the shaft (220; 320; 420; 520; 620; 720) is inserted into the housing interior and each of the series of elongated elastomeric elements (230; 330; 430; 530; 630; 730) is arranged to contact a respective planar shaft outer surface (236; 227; 326; 426) and a pair of adjacent planar housing inner surfaces (216; 316; 416; 516; 616; 716), wherein the series of elongated elastomeric elements (230; 330; 430; 530; 630; 730) provides a torsional spring resistance force between the shaft (220; 320; 420; 520; 620; 720) and the housing (210; 310; 410; 510; 610; 710). [2] The torsion spring and axial control device (200; 300; 400; 500; 600; 700) according to claim 1, wherein the tubular housing (210; 310; 410; 510; 610; 710) has a uniform cross-section along its longitudinal direction. [3] The torsion spring and axial control device (200; 300; 400; 500; 600; 700) of claim 1, wherein the gradual size transition between the first elastomer element end (232; 332; 432) and the second elastomer element end (234; 334; 434) is linear along its longitudinal direction. [4] The torsion spring and axial control device (200; 300; 400; 500; 600; 700) of claim 1, wherein the gradual size transition between the first shaft end (222; 322; 422) and the second shaft end (224; 324; 424) is linear along its longitudinal direction. [5] The torsion spring and axial control device (200; 300; 400; 500; 600; 700) of claim 1, wherein the shaft (220; 320; 420; 520; 620; 720) is configured as a twisted shaft (220; 320; 420; 520; 620; 720). [6] Torsion spring and axial control device (200; 300; 400; 500; 600; 700) according to claim 1, wherein the shaft (220; 320; 420; 520; 620; 720) is truncated pyramid-shaped. [7] The torsion spring and axial control device (200; 300; 400; 500; 600; 700) of claim 1, wherein the tubular housing (210; 310; 410; 510; 610; 710) is formed with a number of n sides and the shaft (220; 320; 420; 520; 620; 720) is formed with a number of n shaft outer surfaces (236; 227; 326; 426), where n is selected from a group consisting of the following: a) three (3) pages, b) four (4) pages, c) five (5) pages, and d) six (6) pages. [8] Torsion spring and axial control device (200; 300; 400; 500; 600; 700) comprising: a shaft (220; 320; 420; 520; 620; 720) having a plurality of planar outer surfaces (236; 227; 326; 426) extending between a peripheral edge of a first shaft end (222; 322; 422) and a peripheral edge of a second shaft end (224; 324; 424), wherein a cross-sectional area of the first shaft end (222; 322; 422) is smaller than a cross-sectional area of the second shaft end (224; 324; 424), and a cross-sectional shape whose size gradually transitions between the first shaft end (222; 322; 422) and the second shaft end (224; 324; 424); a series of elongated elastomeric elements (230; 330; 430; 530; 630; 730), each elongated elastomeric element (230; 330; 430; 530; 630; 730) having a first elastomeric element end (232; 332; 432) and a second elastomeric element end (234; 334; 434), the first elastomeric element end (232; 332; 432) having a smaller cross-sectional area than the second elastomeric element end (234; 334; 434), the size of a cross-sectional shape of the elastomeric element (230; 330; 430; 530; 630; 730) gradually decreasing between the first elastomeric element end (232; 332; 432) and the second elastomer element end (234; 334; 434); and a tubular housing (210; 310; 410; 510; 610; 710) comprising a plurality of planar inner surfaces (216; 316; 416; 516; 616; 716) defining a housing interior, the tubular housing (210; 310; 410; 510; 610; 710) having a uniform cross-section along its length and adjacent edges of adjacent pairs of planar inner surfaces (216; 316; 416; 516; 616; 716) being joined at an angular transition (218; 318; 418; 518; 618; 718), wherein the shaft (220; 320; 420; 520; 620; 720) is inserted into the housing interior and each of the series of elongated elastomeric elements (230; 330; 430; 530; 630; 730) is arranged to contact a respective planar shaft outer surface (236; 227; 326; 426) and a pair of adjacent planar housing inner surfaces (216; 316; 416; 516; 616; 716), wherein the series of elongated elastomeric elements (230; 330; 430; 530; 630; 730) provides a torsional spring resistance force between the shaft (220; 320; 420; 520; 620; 720) and the housing (210; 310; 410; 510; 610; 710). [9] The torsion spring and axial control device (200; 300; 400; 500; 600; 700) of claim 8, wherein the shaft (220; 320; 420; 520; 620; 720) is configured as a twisted shaft (220; 320; 420; 520; 620; 720). [10] The torsion spring and axial control device (200; 300; 400; 500; 600; 700) of claim 8, wherein the gradual size transition between the first elastomer element end (232; 332; 432) and the second elastomer element end (234; 334; 434) is linear along its length. [11] The torsion spring and axial control device (200; 300; 400; 500; 600; 700) of claim 8, wherein the gradual size transition between the first tubular housing end (212; 312; 412) and the second tubular housing end (214; 314; 414) is linear along its length. [12] The torsion spring and axial control device (200; 300; 400; 500; 600; 700) of claim 11, wherein the gradual size transition between the first elastomeric element end (232; 332; 432) and the second elastomeric element end (234; 334; 434) is linear along its length. [13] Torsion spring and axial control device (200; 300; 400; 500; 600; 700) according to claim 8, wherein the tubular housing (210; 310; 410; 510; 610; 710) is truncated pyramid-shaped. [14] Torsion spring and axial control device (200; 300; 400; 500; 600; 700) according to claim 8, wherein the tubular housing (210; 310; 410; 510; 610; 710) is formed with a number of n sides and the shaft (220; 320; 420; 520; 620; 720) is formed with a number of n shaft outer surfaces (236; 227; 326; 426), where n is selected from a group consisting of the following: a) three (3) pages, b) four (4) pages, c) five (5) pages, and d) six (6) pages. [15] Torsion spring and axial control device (200; 300; 400; 500; 600; 700) comprising: a tubular housing (210; 310; 410; 510; 610; 710) having a first housing end (212; 312; 412), a second housing end (214; 314; 414), and a plurality of planar walls (216; 316; 416; 516; 616; 716) extending therebetween, each planar wall (216; 316; 416; 516; 616; 716) defining a housing interior, adjacent edges of adjacent pairs of planar interior surfaces (216; 316; 416; 516; 616; 716) being joined at an angular transition (218; 318; 418; 518; 618; 718), a shaft (220; 320; 420; 520; 620; 720) having a first shaft end (222; 322; 422), a central shaft constriction (323, 423) and a second shaft end (224; 324; 424), wherein the central shaft constriction (323, 423) is smaller than the first shaft end (222; 322; 422) and the second shaft end (224; 324; 424), wherein a first row of planar outer surfaces (236; 227; 326; 426) extends between a peripheral edge of the first shaft end (222; 322; 422) and a peripheral edge of the central shaft constriction (323, 423), wherein the first row planar outer surfaces (236; 227; 326; 426) forms a first polygonal truncated portion and a second row of planar outer surfaces (236; 227; 326; 426) extends between a peripheral edge of the central shaft constriction (323, 423) and a peripheral edge of the second shaft end (224; 324; 424), wherein the second row of planar outer surfaces (236; 227; 326;426) forms a second truncated polygon, the first truncated polygon being opposite the second truncated polygon; a series of elongated elastomeric elements (230; 330; 430; 530; 630; 730), each elongated elastomeric element (230; 330; 430; 530; 630; 730) having a first elongated elastomeric element end (232; 332; 432), a middle section (333, 433) in the elongated elastomeric element (230; 330; 430; 530; 630; 730) and a second elongated elastomeric element end (234; 334; 434), the middle section (333, 433) in the elongated elastomeric element (230; 330; 430; 530; 630; 730) is larger than the first elongated elastomer element end (232; 332; 432) and the second elongated elastomer element end (234; 334; 434), wherein a first outer surface segment extends between a peripheral edge of the first elongated elastomer element end (232; 332; 432) and a peripheral edge of the middle section (333, 433) in the elongated elastomer element (230; 330; 430; 530; 630; 730), wherein the first outer surface (336; 436) forms a first truncated cone, and wherein a second outer surface segment (336;436) extends between a peripheral edge of the second elongate elastomeric element end (234; 334; 434) and a peripheral edge of the middle section (333, 433) in the elongate elastomeric element (230; 330; 430; 530; 630; 730), the second outer surface (336; 436) forming a second truncated cone, the first truncated cone being opposite the second truncated cone, the first and second truncated cones being arranged such that an offset angle is formed between their longitudinal axes, such that the elongate elastomeric element (230; 330; 430; 530; 630; 730) forms an angled biconic elongate elastomeric element (230; 330; 430; 530; 630; 730) having a linear housing contact surface segment (337; 437) and a triangular shaft contact surface segment (338; 438); and; wherein the shaft (220; 320; 420; 520; 620; 720) is inserted into the housing interior and each of the series of elongated elastomer elements (230; 330; 430; 530; 630; 730) is arranged such that the triangular shaft contact surface segment (338; 438) contacts a respective planar shaft outer surface (236; 227; 326; 426) and the housing contact surface segment (337; 437) contacts a pair of adjacent planar housing inner surfaces (216; 316; 416; 516; 616; 716), wherein the series of elongated elastomer elements (230; 330; 430; 530; 630; 730) provides a torsional spring resistance force between the shaft (220; 320; 420; 520; 620; 720) and the housing (210; 310; 410; 510; 610; 710). [16] The torsion spring and axial control device (200; 300; 400; 500; 600; 700) of claim 15, wherein the tubular housing (210; 310; 410; 510; 610; 710) has a uniform cross-section along its length. [17] The torsion spring and axial control device (200; 300; 400; 500; 600; 700) of claim 15, wherein the gradual size transition between the first elastomer element end (232; 332; 432) and the second elastomer element end (234; 334; 434) is linear along its length. [18] The torsion spring and axial control device (200; 300; 400; 500; 600; 700) of claim 15, wherein the gradual size transition between the first tubular housing end (212; 312; 412) and the second tubular housing end (214; 314; 414) is linear along its length. [19] The torsion spring and axial control device (200; 300; 400; 500; 600; 700) of claim 18, wherein the gradual size transition between the first elastomeric element end (232; 332; 432) and the second elastomeric element end (234; 334; 434) is linear along its length. [20] Torsion spring and axial control device (200; 300; 400; 500; 600; 700) according to claim 15, wherein the tubular housing (210; 310; 410; 510; 610; 710) is formed with a number of n sides and the shaft (220; 320; 420; 520; 620; 720) is formed with a number of n shaft outer surfaces (236; 227; 326; 426), where n is selected from a group consisting of the following: a) three (3) pages, b) four (4) pages, c) five (5) pages, and d) six (6) pages.

Images