"continuously varying rate suspension"

Abstract

Continuously Varying Rate Suspension The continuously varying rate suspension (100), in accordance with the disclosed invention, comprises a foam spring (10), U-bolts (20), leaf spring assembly (30), an asymmetric straddle mounting bracket with u-slots (40), a frame support bracket (50), a frame bottom cup bracket (60), a mounting cup bracket (70), a shackle (80), and a suspension pin (90), and it provides better ride comfort and handling, it provides improvement in durability of the suspension system, it provides higher payload carrying capacity with uptime increments, it ensures low noise, vibration and harshness levels, it is lighter in weight, and it is eco-friendly and has a lower carbon footprint than other leaf spring suspensions.

Description

TITLE OF THE INVENTION “Continuously Varying Rate Suspension”Field of Invention

[0001] The invention relates to suspension systems provided on commercial vehicles. It more particularly relates to suspension systems utilising leaf springs.Background of the Invention

[0002] The existing conventional rear suspension system of light and medium-duty trucks comes with a semi -elliptical leaf spring in combination with a helper leaf pack. However, the conventional system has its limitations regarding ride comfort as it works with two-stage stiffness variation, which leads to sudden changes in ride frequency. Also, when the helper leaf comes in contact with the helper bracket, it gives a jerky ride. This also results in the degradation of suspension and chassis life as stresses on the leaf spring increase in higher load conditions. Therefore, the maintenance of the conventional system is higher as there are more serviceable parts.

[0003] In today’s market, demand for a better ride, comfort, and higher loadcarrying capacity has drastically increased. Therefore, an objective of the present invention is to provide a continuously varying rate suspension that can continuously vary its spring stiffness characteristics depending upon loading conditions.

[0004] It is another objective of the present invention is to provide a continuously varying rate suspension that ensures better ride and comfort as it gives constant ride frequency at various load conditions compared to conventional systems.

[0005] It is still another obj ective of the present invention to provide a continuously varying rate suspension with improved maintainability.

[0006] It is yet another objective of the present invention to provide a continuously varying rate suspension that is light in weight and has a higher payload-carrying capacity.Summary of the Invention

[0007] The invention achieving the stated objectives, i.e. the continuously varying rate suspension comprises of a foam spring, U-bolts, leaf spring assembly, an asymmetric straddle mounting bracket with u-slots, a frame support bracket, a frame bottom cup bracket, a mounting cup bracket, a shackle and a suspension pin. In the continuously varying rate suspension, the foam springs are mounted in a cup provided on the lower surface of the frame bottom cup bracket and the mounting cup bracket. A pair of U-bolts located along the centre of the leaf spring assembly holds two mounting ends of the asymmetric straddle mounting bracket with U-slots on the upper surface of the leaf spring assembly and fastens the asymmetric straddle mounting bracket with U-slots and the spring assembly onto the axle of the vehicle. The frame support backets have a horizontal flat projection that are vertical to their base and that are attached with the vehicle chassis through their base, and the mounting cup brackets through their horizontal flat projection. The shackle links the other end of the leaf spring assembly to a bracket attached to the vehicle chassis through a bush fixed at the other end of said leaf spring assembly. The suspension pin received in the bush provided within in an eye formed at one end of the leaf spring assembly links the one end of the leaf spring assembly to the bracket attached to the vehicle chassis.Brief Description of Drawings

[0008] The present invention is illustrated in the accompanying drawings. The description of the present invention would, therefore, be better understood with reference to accompanying diagrams, wherein

[0009] Figure 1 discloses an isometric view of the suspension as per an embodiment of the present invention.

[0010] Figure 2 discloses an exploded view of the suspension in accordance with the present invention, as disclosed in Figure 1.

[0011] Figure 3 discloses a side view of the present invention as installed on the vehicle in its unloaded condition, as disclosed in Figure 2.

[0012] Figure 4 discloses another side view of the present invention as installed on the vehicle in its loaded condition, as disclosed in Figure 2.Detailed Description of the Invention

[0013] Referring to the set of figures 1 and 2, a continuously varying rate suspension (100) in accordance with the present invention, comprises of foam spring (10), U-bolts (20), leaf spring assembly (30), an asymmetric straddle mounting bracket with u-slots (40), frame support brackets (50), a frame bottom cup bracket (60), mounting cup brackets (70), a shackle (80), and a suspension pin (90).

[0014] The foam springs (10) are mounted in a cup provided on the lower surface of the frame bottom cup bracket (60) and the mounting cup bracket (70). A pair of U- bolts (20) located along the centre of the leaf spring assembly (30) holds two mounting ends of the asymmetric straddle mounting bracket with U-slots (40) on the upper surface of the leaf spring assembly (30) and fastens the asymmetric straddle mounting bracket with U-slots (40) and the spring assembly (30) onto the axle of the vehicle.

[0015] The frame support backet (50) have a horizontal flat projection that are vertical to their base and that is attached with the vehicle chassis through their base, and the mounting cup brackets (70) through their horizontal flat projection. The shackle (80) links the other end of the leaf spring assembly (30) to a bracket attached to the vehicle chassis through a bush fixed at the other end of said leaf spring assembly (30). The suspension pin (90) received in the bush provided within an eye formed at one end of the leaf spring assembly (30) links the one end of the leaf spring assembly (30) to the bracket attached to the vehicle chassis.

[0016] Referring to Figs. 3 & 4, in the continuously varying rate suspension (100), the foam springs (10) affixed in the cup on the lower surface of the mounting cup brackets (70) that are in turn attached to the frame support brackets (50), are together configured so as to enable the lower end of the foam springs (10) to come to rest on two raised arms of the asymmetric straddle mounting bracket with U-slots (40). The lower surface of the foam springs (10) can come to rest on a touch pad area provided on the two raised arms of the asymmetric straddle mounting bracket with U-slots (40) while the vehicle is being operated.

[0017] In the continuously varying rate suspension (100), the foam spring (10) affixed in the cup on the lower surface of the frame bottom cup bracket (60) that is in turn attached to the vehicle chassis, are together configured so as to enable the lower end of the foam springs (10) to come to rest against axle of the vehicle.

[0018] As per the overall packing of the continuously varying rate suspension (100), as shown in Figure 3 & 4, the continuously varying rate suspension (100) has four different mounting brackets for smooth functioning and increased maintainability as the variety of parts decreased by 40%. Each bracket has its own unique functioning in the system. First is the Asymmetric Straddle Mounting bracket with U-slots (40); as it’s mounted on a leaf spring, it acts as a U-bolt clamp, and mainly used as touch pad for side frame-mounted foam springs (10). The Asymmetric Straddle Mounting bracket with U-slots (40) also helps to distribute the load uniformly between foam springs (10) and leaf springs (30).

[0019] Also, the Asymmetric Straddle Mounting bracket with U-slots (40) has sufficient touch pad area on its two extended arms to avoid foam springs getting offside in all loading conditions after touching, as shown in figure 3 & 4. Then, the Frame Support Bracket (50) provides two functions: one is used for mounting the mounting cup bracket (70), and the other is to provide support to sustain the higher loads. The third one is the mounting cup bracket, which is mounted with the help of a side framemounting bracket by bolts. Where the cup has a cavity to press, fit the foam spring (10) in such a way that it wouldn’t loose its grip as the continuously varying rate suspension (100) moves in a longitudinal direction after engagement due to shackle (80) movement. Then the last one is the frame bottom cup bracket (60), which is utilized to mount the third foam spring (10) to touch the axle at the same time that the outer foam springs (10) will remain in contact with the axle land area throughout the working region. Therefore, the overall system is easy to maintain and easy to assemble.

[0020] Figure 3 shows the continuously varying rate suspension (100) in its unladen condition. In the unladen condition the leaf spring assembly (30), which is linked to the vehicle through vehicle mounted brackets located along its either ends via the suspension pin (90) received within the bush provided in the eye formed at its one end and the shackle (80) through the bush fixed at its other end and held together by straps placed at regular intervals on its leaf springs, is in its unloaded condition. In the unladen condition, the load transfer path is formed by the vehicle chassis, then the vehicle mounted brackets, then the shackle (80) and the suspension pin (90), then the leaf spring assembly (30), and then the vehicle’s axle. This remains the load transfer path until the loading on the vehicle chassis is below a threshold weight i.e. the leaf spring assembly (30) gets deformed beyond a certain threshold extent to allow the foam springs (10) to come into contact with the axle and the touch pad area on the arms of the asymmetric straddle mounting bracket with u-slots (40) respectively.

[0021] Figure 4 shows the continuously varying rate suspension (100) in its fully laden condition. This state is achieved when load applied by the chassis has increased beyond a threshold magnitude and the leaf spring assembly (30) has deflected enough to allow the foam springs (10) to respectively come in contact with the axle and the asymmetric straddle mounting bracket with u-slots (40). In this condition, in addition to load transfer path for the unladen condition, there are two additional load transfer paths. The second load transfer path is formed by the vehicle chassis, then the frame support brackets (50), then the mounting cup brackets (70), then the foam springs (10), then the asymmetric straddle mounting bracket with u-slots (40), then the leaf springassembly (30) and then the vehicle’s axle. The third load transfer path is formed by the vehicle chassis, then the frame bottom cup bracket (60), then the foam spring (10), and then the vehicle’s axle. In the laden condition (Refer to Fig. 4) there are four springs (three foam springs (10) and the leaf spring assembly (30)) that are functioning to absorb and later release energy as the vehicle chassis gets loaded and then later unloaded.

[0022] The resultant effect of providing three load transfer paths is that after the threshold chassis loading is reached and the leaf spring assembly (30) gets sufficiently deformed, the foam springs (10) come into contact with axle and the asymmetric straddle mounting bracket with u-slots (40) respectively. The four springs (three foam springs (10) and the leaf spring Assembly (30)) then start compressing simultaneously, a continuously varying rate (spring rate) is achieved, which gives a better suspension performance and hence a more comfortable ride. The switch between laden and unladen state can take place repeatedly while the vehicle is being operated on a road i.e. getting loaded or unloaded or are encountering road surface irregularities while moving.

[0023] The continuously varying rate suspension (100) in accordance with the disclosed construction achieves all the stated objectives.

[0024] Technical advantages offered by the invention, i.e., the continuously varying rate suspension (100), are that- it provides better ride comfort and handling. it provides improvement in durability of the suspension system. it provides higher payload carrying capacity with uptime increments. it ensures low noise, vibration and harshness levels. it is lighter in weight. it is eco-friendly and has a lower carbon footprint than other leaf spring suspensions.

[0025] It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the present invention has been herein described in terms of its preferred embodiment, those skilled in the art will recognise that the preferred embodiment herein disclosed can be practised with modifications within the scope of the invention herein described.

Claims

CLAIMS:We claim,1. A continuously varying rate suspension (100) comprising:• foam springs (10);• U-bolts (20);• leaf spring assembly (30);• an asymmetric straddle mounting bracket with u-slots (40);• frame support brackets (50);• a frame bottom cup bracket (60);• mounting cup brackets (70);• a shackle (80); and• a suspension pin (90); wherein,- the foam springs (10) are mounted in a cup provided on the lower surface of the frame bottom cup bracket (60) and the mounting cup bracket (70); a pair of U-bolts (20) located along the centre of the leaf spring assembly (30) holds two mounting ends of the asymmetric straddle mounting bracket with U-slots (40) on the upper surface of the leaf spring assembly (30) and fastens the asymmetric straddle mounting bracket with U-slots (40) and the spring assembly (30) onto the axle of the vehicle;- the frame support backets (50) have a horizontal flat projection that are vertical to their base and that are attached with the vehicle chassis through their base, and the mounting cup brackets (70) through their horizontal flat projection;- the shackle (80) links the other end of the leaf spring assembly (30) to a bracket attached to the vehicle chassis through a bush fixed at the other end of said leaf spring assembly (30) and- the suspension pin (90) received in the bush provided within in an eye formed at one end of the leaf spring assembly (30) links the one end of the leaf spring assembly (30) to the bracket attached to the vehicle chassis.

2. The continuously varying rate suspension (100), as claimed in claim 1, wherein the foam springs (10) affixed in the cup on the lower surface of the mounting cup brackets (70) that are in turn attached to the frame support brackets (50), are together configured so as to enable the lower end of the foam springs (10) to come to rest on two raised arms of the asymmetric straddle mounting bracket with U- slots (40).

3. The continuously varying rate suspension (100), as claimed in claim 1, wherein the foam spring (10) affixed in the cup on the lower surface of the frame bottom cup bracket (60) that is in turn attached to the vehicle chassis, are together configured so as to enable the lower end of the foam springs(lO) to come to rest against axle of the vehicle.

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