Steering damper for a motor vehicle

Abstract

Steering damper (10, 10', 100, 200, 300) for a vehicle comprising the following: a damping element (12) comprising a housing (22) and a piston rod (16) extending telescopically from the housing (22); a coil spring (20) arranged above the damping element (12); an internal connection arrangement (14) which is operatively assigned to the damping element (12) for securing a first end (20a) of the damping element (12) to a wheel component or a body component of the vehicle; an external connection arrangement (18) which is operatively coupled to a distal end of the piston rod (16) for coupling the respective other component - the wheel component or the body component - of the vehicle; a one-piece tubular spring seat which is firmly coupled to the housing (22) of the damping element (12) and this circumferentially surrounds, to be held stationary with respect to the housing (22), wherein the one-piece tubular spring seat comprises the following: a retaining ring (40a, 40b, 40', 140a, 240b, 340b); a first groove formed on an outer surface (22a) of the housing (22) of the damping element (12); a second groove formed on an inner surface of the one-piece spring seat (24, 24', 124, 324), and wherein the retaining ring (40a, 40b, 40', 140a, 240b, 340b) is axially stationary on the housing (22) for holding the one-piece tubular spring seat, engaging with both the first and the second groove; an anti-rotation device that limits rotation between the one-piece tubular spring seat and the housing (22); the coil spring is supported at a first end (20a) by the one-piece spring seat (24, 24', 124, 224, 324) and at a second end (20b) by the outer connection arrangement (18), characterized in that the one-piece tubular spring seat comprises an outer surface (22a) and a spiral groove (36) formed thereon, wherein the first end (20a) of the coil spring (20) is positioned in the spiral groove (36); and wherein the one-piece spring seat (24, 24', 124, 224, 324) responds to a load on the coil spring (20) in such a way as to return the steering damper (10, 10', 100, 200, 300) to a neutral or mid-position when a neutral steering input is applied by an operator of the vehicle, regardless of whether the coil spring (20) is compressed or stretched.

Description

[0001] The present disclosure relates to steering dampers used in motor vehicles, such as cars, trucks, off-road vehicles, motorhomes, etc., and in particular to a steering damper with a one-piece construction which allows the steering damper to return to a neutral position when no steering torque is applied to the vehicle's steering system.

[0002] Steering dampers are used in motor vehicles, and especially in vehicles with large wheels and tires, such as SUVs, vans, trucks, motorhomes, off-road vehicles, etc. A steering damper can help reduce vibrations caused by large wheels and tires and generally improve a vehicle's overall handling. However, most steering dampers do not include a mechanism for automatically returning the damper to a neutral position once the driver turns the steering wheel to neutral. Furthermore, many current steering dampers feature a two-piece flap configuration, typically formed by a two-piece aluminum casting, with fasteners (e.g., threaded fasteners such as spring washer bolts) used to hold the two pieces of the assembly together on the damping element.Installing the spring seat on the damping element is time-consuming, and there is a possibility that one or more of the fasteners may be overtightened if not properly tightened during installation. A steering damper with the features of the preamble of claim 1 is described in DE 85 100 58 U1. DE 10 2006 016 470 A1 and US 3 951 391 A disclose similar steering dampers.

[0003] The aforementioned problem is solved according to the invention with a steering damper having the features of claim 1. Advantageous embodiments are the subject of the dependent claims.

[0004] The present disclosure relates to a steering damper for a vehicle. The system comprises a damping element having a housing and a piston rod extending telescopically from the housing. A coil spring is included, arranged above the damping element. An inner connection arrangement is operatively associated with the damping element for securing a first end of the damping element to a wheel component or a body component of the vehicle. An outer connection arrangement is operatively coupled to a distal end of the piston rod for coupling the other component—the wheel component or the body component—of the vehicle. A one-piece tubular spring seat is rigidly coupled to the housing of the damping element such that it is held stationary axially with respect to the housing.The one-piece tubular spring seat comprises at least one retaining ring, a first groove formed on an outer surface of the damping element housing, and a second groove formed on an inner surface of the one-piece spring seat. The at least one retaining ring engages the housing with both the first and second grooves to hold the one-piece tubular spring seat in a stationary position. A coil spring is supported at one end by the one-piece spring seat and at the other end by the outer connection assembly.According to the invention, the one-piece tubular spring seat comprises an outer surface and a helical groove formed thereon, wherein the first end of the coil spring is positioned in the helical groove; and wherein the one-piece spring seat responds to a load on the coil spring in such a way as to return the steering damper to a neutral or center position when a neutral steering input is applied by an operator of the vehicle, regardless of whether the coil spring is compressed or under tension. The one-piece spring seat enables the coil spring to return the steering damper to a neutral or center position when a neutral steering input is applied by an operator of the vehicle, regardless of whether the coil spring is compressed or under tension. Fig. Figure 1 is a side cross-sectional partial view of a steering damper according to an embodiment of the present disclosure; Fig. 2 is an enlarged elevation view of the in Fig. 1 spring seat shown; Fig. Figure 3 is an enlarged cross-sectional view of a section of the steering damper, which better shows the one-piece spring seat secured to the damping element housing by the retaining rings; Fig. Figure 4 is a section view of the damping element housing only, which better shows the grooves formed on its outer surface that engage with the pair of retaining rings; and Fig. Figure 5 shows an alternative embodiment of a steering damper according to the present disclosure, in which only a single retaining ring is used to secure the one-piece spring seat to an outer surface of the damping element housing. Fig. Figure 6 is a simplified cross-sectional side view of a further embodiment of the one-piece spring seat, in which raised areas are formed on an outer surface of the outer wall of the damping element housing, which engage with several cutout areas or notches on an inner surface of the spring seat to prevent rotation of the spring seat on the damping element housing; Fig. 7 is a simplified cross-sectional end view of the arrangement of Fig. 6; Fig. Figure 8 is a simplified side view of another embodiment of the one-piece spring seat, showing the spring seat which includes a cutout area that allows access to the single retaining ring used to hold the spring seat to the damping element housing; Fig. Figure 9 is a simplified cross-sectional side view of the arrangement of Fig. 8; Fig. Figure 10 is a simplified cross-sectional side view of a further embodiment of the one-piece spring seat, in which the one-piece spring seat comprises a primary component and a secondary collar arranged coaxially over the primary component; Fig. 11 and Fig. Figure 12 shows a nose formed on the inner surface of the secondary component and a groove formed on the outer surface of the primary component to permit a degree of axial adjustment of the secondary collar on the primary component; Fig. Figure 13 is an end view of the secondary fret of Fig. 12; Fig. Figure 14 is another embodiment of the one-piece spring seat, showing a threaded engagement between the primary component and the secondary collar and a separate locking nut used to lock the secondary collar at a desired axial position on the primary component; Fig. 15 is a simplified side view of the one-piece spring seat of Fig. 10, which, however, includes a modified helical groove comprising an end section with an extended surface for engagement with a flattened distal end section of the spring, which serves to lock the rotation of the one-piece spring seat on the damping element housing; and Fig. Figure 16 is a simplified side view of the one-piece spring seat of Fig. 10, which instead contains a coil spring having a notch at its distal end which engages with a lug formed in the spring seat to lock rotation of the spring seat on the damping element housing.

[0005] Matching reference symbols indicate parts that correspond across different views of the drawings.

[0006] Exemplary embodiments will now be described in more detail with reference to the accompanying drawings.

[0007] With reference to Fig. Figure 1 shows a steering damper 10 according to an embodiment of the present disclosure. The steering damper 10 is a steering damper with “automatic centering”, referred to as RTC (Return-To-Center). The steering damper 10 comprises a damping element 12 having an inner connection arrangement 14, a telescopic piston rod 16, an outer connection arrangement 18, and a coil spring 20. The coil spring 20 is arranged above the piston rod 16 and an outer housing 22 of the damping element 12. A spring seat 24 is used to engage with a first end 20a of the coil spring 20 and to retain the first end relative to the outer housing 22 of the damping element 12.

[0008] A second end 20b of the helical spring 20 is held firmly at a distal end of the piston rod 16. This is achieved by a hexagonal lock nut 26, which is secured to the piston rod 16 via a bushing assembly (e.g., an elastomeric bushing assembly), a retaining element 27, a spring seat washer 28, a counter washer 30, a pivot nut 32, and a screwed-on section 18a of the outer connection assembly 18. These components grasp the second end 20b of the helical spring 20 and hold the second end in coaxial alignment with an axial center of the piston rod 16. Thus, the second end 20b of the helical spring 20 is stretched or elongated when the piston rod 16 extends telescopically outward from the damping element housing 22 (i.e., inwards). Fig. 1 to the left) and is retracted (i.e. moved to the right) when the piston rod 16 is partially retracted into the damping element housing 22.

[0009] The inner connection assembly 14 can be secured to a section of the vehicle's chassis, or possibly to a stabilizer bar or other part of the vehicle that does not rotate with the steering wheel, via a bushing assembly (e.g., an elastomeric bushing assembly), whereas the outer connection assembly 18 can be secured to a tie rod, linkage, or other steering component that moves with rotation of the steering wheel, or to any other component associated with either a wheel or a steering component of the vehicle. Alternatively, this coupling can be reversed, such that the inner connection assembly 14 is secured to the wheel component and the outer connection assembly 18 is secured to the chassis or stabilizer bar.

[0010] The one-piece spring seat 24 forms a unique, single-piece configuration that can be attached to the housing 22 of the damping element 12 even more easily and with a more positive fit than previous designs of spring seats used in steering dampers. As in Fig. As shown in Figure 1, the one-piece spring seat 24 comprises a one-piece body section 34 made of a sufficiently strong material, for example, aluminum or possibly even high-strength plastic. The one-piece body section 34 is a tubular component with a spiral groove 36 formed on it. The outer diameter of the spring seat 24, as well as the depth and overall circumference of the spiral groove 36, allow a section of the first end 20a of the helical spring 20, and preferably the first two coils of the helical spring, to be screwed onto the spiral groove 36 during installation. The first end 20a of the helical spring 20 can thus be screwed onto the one-piece body section 34 up to the point where an outer end of the helical spring 20 abuts a point 38 on the one-piece body section 34.

[0011] With further reference to Fig. 1 and Fig. 3. The one-piece body section 34 can be held firmly on the housing 22 of the damping element 12 by at least one retaining ring, but more preferably by a pair of retaining rings 40a and 40b, which bear against opposite ends of the one-piece spring seat 24. Each retaining ring 40a / 40b forms a generally circular split ring that sits in an associated groove 42a or 42b on an outer surface 22a of the damping element housing 22. The grooves 42a and 42b on the damping element housing 22 are in Fig. 4 is particularly visible. In this example, the damping element housing 22 forms the spare tube of the damping element 12. The grooves 42a and 42b each have a depth dimension that allows a portion of their associated retaining ring 40a or 40b to partially rest in its associated groove 42a or 42b. An inner surface 44 of the one-piece body section 34 of the one-piece spring seat 24 also includes circumferential grooves 44a and 44b formed at each opposite end of the one-piece body section 34. In this example, the grooves 42a and 42b have different depth dimensions, with the groove 42a having a depth dimension that is slightly less than that of the groove 42b.The smaller depth dimension of the groove 42a, together with the circumferential groove 44a, provides only a minimal distance to an inner wall surface of the circumferential groove 44a when the ring 40a is installed in the circumferential groove 44a during assembly and the one-piece spring seat 24 is slid over the damping element housing 22. This minimal distance eliminates the possibility of applying an axial load to the retaining ring 40a that would axially "push" the retaining ring 40a out of the groove 42a. Thus, the minimal radial distance provided by the circumferential groove 44a prevents any perceptible widening of the retaining ring 40a in response to an axial load.

[0012] As mentioned above, the groove 42b is larger (i.e., deeper) than the groove 42a to facilitate the installation of the retaining ring 40b. Specifically, the greater depth of the groove 42b provides the additional clearance required to allow the retaining ring 40b to expand during the installation of the spring seat 24 onto the damping element housing 22. During installation, the retaining ring 40b is slid onto and over the damping element housing 22 while being held in an expanded position using a suitable tool. The retaining ring 40b sits in the groove 42b. The one-piece spring seat 24 is then slid onto the damping element housing 22 and moved axially along the damping element housing 22 until the groove 44b engages with the retaining ring 40b. The retaining ring 40a is then pushed onto the damping element housing 22 and axially along it, while being held in an expanded state.The retaining ring 40a engages in the groove 42a, and at this point, the spring seat 24 is held axially at a predetermined position on the damping element housing 22. Thus, the retaining rings 40a and 40b grip the one-piece spring seat 24 on the damping element housing 22 at a precise axial position and prevent any perceptible axial movement of the one-piece spring seat 24 along the damping element housing 22. The coil spring 20 can then be screwed onto the one-piece spring seat 24, and the rest of the steering damper 10 can be installed. It should be understood, however, that although the above description refers to two retaining rings 40a and 40b for stationary securing of the spring seat 24 to the damping element housing 22, it is possible, as described below in the figure below, to use two retaining rings. Fig. As shown in the embodiment 5, only a single retaining ring is used to axially secure the one-piece spring seat 24.

[0013] The above-described design of the one-piece spring seat 24 and the retaining rings 40a / 40b, grooves 42a / 42b, and circumferential grooves 44a / 44b ensures an extremely fast assembly process. The assembly process does not require the manual screwing in of fasteners, which is necessary with a conventional two-piece spring seat arrangement. Furthermore, the use of split retaining rings 40a / 40b, grooves 42a / 42b, and circumferential grooves 44a / 44b eliminates any possibility of a screwed-in fastener loosening and interfering with the operation of the steering damper 10. Moreover, the one-piece spring seat 24 is inherently more robust than conventional two-piece spring seat components. And the one-piece configuration of the spring seat 24 avoids the potential alignment problems of the two halves that often necessitate the use of a wider helical groove in two-piece spring seat designs.The steering damper 10 offers the significant advantage that the firmly secured, one-piece spring seat 24 allows the coil spring 20 to always return to a central or neutral position. Thus, when the coil spring 20 is stretched and under tension, it assists the pulling of the outer connection assembly 18 to the right when the vehicle operator turns the steering wheel to the central or neutral position. Fig. 1, until the steering damper 10 has returned to its center position. Likewise, when the coil spring 20 is compressed, it assists in supporting the push of the outer connection assembly 18 to the left when the user returns the steering wheel to the center position. Fig. 1, to return the steering damper 10 to its center or neutral position.

[0014] With reference to Fig. Figure 5 shows a steering damper 10' according to a further embodiment of the present disclosure. The steering damper 10' is essentially identical to the steering damper 10, except that a full or at least partial circumferential rib 42' is formed on an outer surface 22a' of a damping element housing 22'. In this embodiment, no circumferential groove 44a is formed on the inner diameter of a one-piece spring seat 24'; instead, an edge 24a' of the one-piece spring seat 24' rests against the circumferential rib 42', thereby allowing axial movement of the one-piece spring seat 24' to the left in the drawing. Fig. 5 is prevented. An opposite end of the one-piece spring seat 24' includes a groove 44' on its inner surface, which may be identical or substantially identical to the groove 44b and which is aligned at least substantially axially with a groove 45' formed in an outer surface of the damping element housing 22'. A single retaining ring 40' is positioned in the groove 45' during assembly. When the single retaining ring 40' is fully inserted into the groove 44' and released, it expands radially outward, and a portion of it abuts a surface edge 24b' of the one-piece spring seat 24'. This prevents any perceptible axial movement of the one-piece spring seat 24' to the right in the drawing of Fig. 5 prevents this. The coil spring (not shown) can then be installed with the one-piece spring seat 24' in the same manner described for the steering damper 10. The design with a single retaining ring for the steering damper 10' can even further simplify assembly procedures and reduce the overall cost of the steering damper 10'.

[0015] Another feature of the above-described embodiment of the spring seat 24, in which two retaining rings 40a and 40b are used, is the provision of overload protection on both retaining rings. To achieve this, the axial distance between the two retaining rings 40a and 40b must be greater than the axial distance between the two circumferential grooves 44a and 44b in the spring seat 24. This allows the spring seat 24 to be slightly translationally movable for installing the retaining ring 40a. In a preferred embodiment, the axial distance between the rings 40a and 40b and the axial distance between the grooves 42a and 42b are no more than the diameter of the retaining ring (that is, either the retaining ring 40a or 40b, which in this example can have the same diameter).

[0016] When the spring seat 24 is loaded, it moves translationally into a position above the retaining ring 40a, where overload protection is achieved. When loaded in the opposite direction, the spring seat 24 again undergoes translational movement, causing a section of it to move translationally over the second retaining ring 40b, thus again providing overload protection.

[0017] A steering damper 100 according to a further embodiment of the present disclosure is in Fig. 6 and Fig. 7 shown. The steering damper 100 is identical to the steering damper 10, except for the design of a damping element housing 122 and a one-piece spring seat 124, and thus the various other components of the steering damper (e.g. the coil spring 20, the outer connection arrangement 18, etc.) which are described in connection with the steering damper 10 are shown in Fig. 6 and Fig. 7 not shown. The steering damper 100 requires only a single retaining ring 140a to hold the spring seat 124 in a precise axial position on the damping element housing 122. Components or features common with the steering damper 10 are described in Fig. 6 and Fig. 7 with reference numbers increased by 100.

[0018] The steering stabilizer 100 uses a one-piece spring seat 124, which only employs a single retaining ring 140a at its upper end. The single retaining ring 140a is partially held in a groove 142a in the damping element housing 122. In this embodiment, the lower retaining ring and the lower spare tube groove are not required. Instead of a groove forming a complete 360-degree groove in an outer surface of the damping element housing 122, the outer surface wall of the damping element housing 122 is raised at several separate locations, as indicated by raised housing areas 122a. In this embodiment, three separate raised housing areas 122a are used, although it is understandable that a higher or lower number of raised housing areas 122a could be used. Three raised housing areas 122a allow for an even distribution of the load from the spring around the spring seat 124.The use of three raised housing areas 122a also offers an important advantage, namely that it provides a means of preventing rotation of the second end (i.e., the inner or lower end) of the helical spring 20. It is noted that the rod end (i.e., the outer or upper end) of the helical spring 20 is shown in Figure 1. Fig. 1 already has a spring anti-rotation feature. The three raised housing areas 122a are further positioned on the outer wall of the damping element housing 122 such that they can each be received between adjacent pairs of three spaced-apart lower grooves 124a, which are formed on an inner surface of the spring seat 124 next to its lower edge 124b. In this way, the interlocking raised housing areas 122a and the spaced-apart grooves 124a not only hold the spring seat 124 in a precise axial position on the damping element housing 122, but also prevent rotation of the spring seat.

[0019] It is further understood that the raised housing areas 122a and the grooves 124a could possibly be reversed, so that they are instead arranged at the upper end of the spring seat 124. However, since the peak load usually occurs during compression and is directed towards the inner connection arrangement 14 ( Fig. 1) It is assumed that the positioning of the raised housing areas 122a and the grooves 124a at the lower end of the spring seat 124 is preferred in most applications.

[0020] With reference to Fig. 8 and Fig. Figure 9 shows a steering damper 200 according to yet another embodiment of the present disclosure. Again, in the steering damper 200, only the connection between a one-piece spring seat 224 and an outer wall of a damping element housing 222 with respect to the connection with Fig. The steering damper 10 described in section 1 has been modified. Components common to the steering damper 10 have been designated with reference numerals increased by 200.

[0021] The one-piece spring seat 224 is again used with only a single retaining ring 240b and a single groove 242b at a lower end of the spring seat 224. In this embodiment, the single retaining ring 240b is used to prevent movement of the spring seat 224 in the axial direction both upwards and downwards, as shown in Fig. 8, indicated by the arrow “A”. The spring seat 224 utilizes only a single inner groove 244b, which has a depth (i.e., an inner diameter) sufficient to allow the diameter of the retaining ring 240b to increase sufficiently during assembly. This means that during assembly, the retaining ring 240b is initially compressed to reduce its diameter so that it guides into the spring seat 224. Once the retaining ring 240b reaches the position of the single inner groove 244b, the retaining ring 240b snaps back to its initial diameter (i.e., expands radially outward). However, when the retaining ring 240b is positioned against the outer wall of the damping element housing 222, the diameter of the retaining ring increases (i.e., the retaining ring expands radially outward).The diameter remains in this expanded state while the retaining ring 240b is slid along the outer wall of the damping element housing 222 until the retaining ring reaches the groove 242b. At this point, the retaining ring 240b snaps into the groove 242b in the outer wall of the damping element housing 222. In this position, the retaining ring is located in both the groove 242b of the damping element housing 222 and the groove 244b on an inner wall section of the spring seat 224. In this embodiment, a small cutout region 225, possibly on the order of 0.25 inches to 0.50 inches in circumference, may also be located in the outer wall of the spring seat 224 in close proximity to the ends of the retaining ring 240b. It is further understood that instead of the cutout region 225, a hole could be positioned in the outer wall.

[0022] The cutout area 225 serves a dual purpose. First, during installation, when the axial translational movement of the retaining ring 240b occurs on the damping element housing 222, the outer coating (i.e., paintwork) of the damping element housing 222 can be damaged. However, because of the cutout area 225, a tool can be used to hold the retaining ring 240b in a sufficiently expanded position as it is moved over the damping element housing 222 toward the groove 242b, and the clearance provided by the cutout area 225 allows the installer to insert the retaining ring 240b into the groove 242b. Without the cutout area 225, the installer would not be able to position the retaining ring 240b over the groove 242b due to its overlap with the spring seat 224.This allows the installation of the retaining ring 240b without causing potential damage or abrasion to the outer surface coating of the damping element housing 222. Secondly, the cutout area 225 provides access to the ends of the retaining ring 240b with a suitable tool when maintenance is required on the spring seat 224, thus enabling the removal of the retaining ring and the spring seat 224.

[0023] A steering damper 300 according to a further embodiment of the present disclosure is in Fig. Figure 10 shows that only the construction of the damping element housing 322 and the one-piece spring seat 324 differ from that of the steering damper 10. Components common to the steering damper 10 are designated with reference numerals increased by 300. In this embodiment, the one-piece spring seat 324 incorporates a user-selectable spring rate under impact, providing resistance to load during both compression and extension. This performance is achieved by subdividing the helical groove of the spring seat 324 that holds the spring, thus providing a coaxially arranged two-piece spring seat with a primary component 324a and a secondary collar 324b. The features of the retaining ring 340b for preventing axial movement remain unchanged on the primary component 324a and are therefore largely the same as those of the spring seat 224. Fig. 8 identical, except for a circumferential shoulder 324a1 formed on an outer diameter of the primary component 324a. Thus, the spring seat 324 includes a cutout area 325, an inner groove 344b, a retaining ring 340b, and a groove 342b formed on the outer surface of the damping element housing 322. To provide adjustable tension on the spring (e.g., the in Fig. In the helical spring 20 shown in Figure 1, the secondary collar 324b has a lug 324b1 which runs in a stepped groove 324a3 of the primary component 324a, as shown in Figure 1. Fig. 11 and Fig. Figure 12 shows the secondary collar 324b with its radially inwardly projecting nose 324b1. Fig. Figure 13 shows that by rotating the secondary collar 324b on the non-translationally movable primary component 324a, the axial position of the secondary collar 324b is modified. A linear groove 324a2 provides a path for inserting the lug 324b1 into the stepped groove 324a3 when the secondary collar 324b is slid over the primary component 324a during assembly. It is further understood that the lug 324b1 and the groove 324a3 on these two components could be interchanged.

[0024] As an alternative height setting, the non-translationally movable primary component 324a, which is located in Fig. As shown in 10, the secondary collar 324b may be provided with an external thread 324a4 and the secondary collar 324b may be provided with an internal thread 324b2, as shown in Fig. Figure 14 shows the threaded connection 324a4 / 324b2 being used to adjust the axial position of the secondary collar 324b on the primary component 324a. A locking nut 327 can then be provided to secure components 324a and 324b in the desired axial position.

[0025] In some cases, it may be necessary to lock the rotation of the one-piece spring seat 324 on the damping element housing 322. The use of the three raised areas, housing areas 122a and cutout areas 124a, as described herein, is one possibility. Another possibility is to machine the end of the helical spring 20 to a slightly larger diameter and to modify the helical groove 36 in the spring seat 324 to accommodate the larger diameter distal end section of the helical spring 20, as shown in [reference]. Fig. 15 with a slightly larger cross-sectional area 36a to be machined. Another alternative arrangement is described in Fig. Figure 16 shows the formation of a notch 36b in the helical groove 36 at its distal end section, which has a small protrusion 324c. Further alternative possibilities for preventing rotation of the helical spring 20 include changing the coil-to-coil gap to have a smaller gap at the distal end of the helical spring 20. The coil-to-coil gap at the end of the helical spring 20 would first have to widen to match the wider coil-to-coil gap at the beginning of the helical groove 36 at the spring seat 324.

[0026] Furthermore, the radius of the helical spring 20 can be changed to a smaller radius at its distal end. The radius of the helical spring 20 must first widen to fit the larger diameter of the beginning of the helical groove 36 of the spring seat 324. Additionally, the bottom of the helical groove 36 can be raised at a point away from the distal end to prevent the spring from being driven out under repeated loading. Furthermore, a threaded fastener or a threaded pin could be placed in the spring seat 324 to clamp the spring seat against the outer wall of the damping element housing 322.

[0027] Another possibility for eliminating the rotation of the spring seat 24 would be to use a standard set screw that is screwed into a threaded bore in the spring seat and comes into contact with the outer surface of the damping element housing 22. Such an arrangement is very cost-effective and would not significantly complicate the installation of the system 10. When loosened, the set screw allows the spring seat 24 to move and rotate freely for installation; however, when the set screw is properly tightened, it prevents unwanted rotation of the spring seat.

[0028] A further advantage of each of the one-piece spring seats 24, 124, 224, and 324 described here, compared to the prior art, is that a well-known two-piece spring seat configuration according to the prior art requires a larger flute diameter to accommodate misalignment between the helical grooves of the two halves of the key seat. Without the larger grooves, any misalignment of the two halves of the two-piece spring seat prevents the end of the spring from being screwed onto the grooves of the assembled halves. Thus, with a one-piece spring seat featuring a continuous helical groove, it is no longer necessary to have the strict tolerance control during manufacturing that is otherwise required when using two spring seat halves.

Images