FIELD OF THE INVENTION

The invention generally relates to foot rest assembly for a motorcycle and more particularly to a vibration reduction arrangement for a foot rest assembly.

BACKGROUND OF THE INVENTION

Generally, in vehicles, stiffness for structures can be defined in terms of static stiffness and dynamic stiffness. Even though structures are stiff statically, resonance of the structure will make it to flex at finite amplitude at certain frequencies causing discomfort to the rider. Thus, tuning dynamic stiffness is more important compared to static stiffness from rider comfort point of view, to avoid resonance and minimizing the vibration levels in the operating range.

As per existing technology and general practice, foot rest assembly is supported at one end with an overhang at the other end. Apart from the forced excitation, the foot rest assembly is subjected to resonance in operating range and hence amplitude due to forced response or resonance tends to increase at free end or the foot support structure or the foot peg that result in high vibration.

Accordingly, the present invention provides a simple and durable solution for the above described issue. The frequency range of interest is from 0 Hz to 150 Hz where vibration levels are measured in terms of acceleration.

SUMMARY OF THE INVENTION

Main objective of the present invention is to provide a foot rest assembly for a motorcycle having a primary structure consisting of foot support unit fixed on outer side of a holding cavity. This holding cavity has primary multiple mounting blocks fixed on its outer periphery and some support mounting blocks fixed on its inner side. Said support mounting blocks are configured to hold a support plate through fastening units which is called as the secondary structure hereon. The foot rest assembly, consisting of primary and secondary structure, is mounted over frame of the motorcycle through mounting blocks on left and right side of the vehicle.

Present arrangement of the foot rest assembly ensures less vibration at the free end or the foot support unit as the support plate is fixed with the holding cavity. This arrangement results in shift of resonances of the holding cavity and reduces the amplitude of the forced response at free end i.e. the foot support unit.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from the detailed description given herein below and the accompanying drawing which is incorporated in and constitute embodiments of the invention, illustrate several aspects of the invention and together with a description of the embodiments serve to explain the principles of the invention and thus, are not limited of the present invention and a brief description of the drawing is as follows:

Figure 1 and Figure 2 is depicting mounting location of the claimed invention over the motorcycle.

Figure 3 is showing the mounting details of the claimed foot rest assembly on both sides of vehicle.

Figure 4 and Figure 5 are explaining the constructional and assembly details of the claimed foot rest assembly.

Figure 6 shows the comparison of acceleration at foot support unit with and without secondary structure.

DETAILED DESCRIPTION OF THE INVENTION

The embodiments disclosed below are not intended to be exhaustive or to limit the invention to the precise forms disclosed in the following detailed description. Rather, the embodiments are chosen and described for enablement purpose of the invention. The invention may have application to all types of vehicles. The scope of the invention is entirely based upon the claims provided.

Reference is made to Figure 1, Figure 2 and Figure 3 for description of mounting location of the foot rest assembly 103 in the motorcycle M. Engine 101 is mounted on the frame 100 through a mounting bracket 102. Swing arm 104 is connecting axle 002 of rear wheel 001 with the engine bracket 102. Further, foot rest assembly 103 is fixed with engine bracket 102 and swing arm 104 through mounting blocks 105, 106 of the holding cavity 003. As shown in Figure 3 foot rest assembly 103 is secured on both sides of the motorcycle M.

Further, referring to Figure 4 and Figure 5, foot rest assembly 103 has three different parts viz. foot support unit 109, holding cavity 003 and a support plate 110. Foot support unit 109 is fixed with holding cavity through mounting point 108 such that its centre falls on point 104c at which has maximum dynamic response because of a free end. Locations 104a, 104b neighbouring mounting blocks 105,106 has minimum dynamic response due to support provided by engine mounting bracket 102 and the swing arm 104.

A support plate 110 is added to the holding cavity 003 in such a way that surface area of said support plate 110 extends from location of less dynamic response 104a, 104b to the location of highest dynamic response 104c. Thus the support plate 110 is designed in such a way that it is fixed at mentioned locations i.e. 104a, 104b and 104c through fastening members 107. This arrangement of the support plate 110 is done in a way that resonances of the holding cavity 003 is shifted through the support plate 110 while reducing the amplitude of the forced response at free end or the foot support unit 109.

Locations 104a and 104b are considered to be nodal location where dynamics response is found to be the least owing to its vicinity of the holding cavity to the mounting locations 105,106 and dynamic property of the secondary structure (the support plate 110 arrangement). This secondary structure helps in reducing the compliance of the holding cavity 003 all three orthogonal directions, viz. X, Y, Z of interest with appropriate cross section, shape and thickness.

The aforementioned factors impart the primary structure with both static and dynamic stiffness thereby enhancing the strength of the holding cavity and comfort of the rider. The shape of the secondary structure is optimized to shortest distance between nodes and anti-nodes and its dynamic stiffness.

Further, Figures 6 is providing a comparison of the vibration levels in terms of acceleration at location 109 with and without secondary structure for foot rest assembly for X-direction. The dotted curve shows the effect of ..secondary structure from 0 Hz to 150 Hz compared to the acceleration levels without the secondary structure.

WHAT IS CLAIMED IS

1) A foot rest assembly for a motorcycle comprising:

a foot support unit fixed on outer side of a holding cavity characterized by a plurality of mounting blocks fixed on outer periphery of the holding cavity; and

atleast a support mounting block, fixed on the inner side of the holding cavity and configured to hold a support plate through a fastening unit such that the holding cavity, the plurality of mounting blocks, the support mounting block and the support plate are integrated with each other;

wherein, said foot rest assembly is mounted over a frame of the motorcycle through the plurality of mounting blocks at atleast one location.

2) The foot rest assembly, as claimed in claim 1, wherein the plurality of mounting block is defined an anti-nod mounting block.

3) The foot rest assembly, as claimed in claim 1, wherein the support mounting block is defined as a nod mounting block.

4) The foot rest assembly, as claimed in claim 2 and claim 3, wherein the anti nod mounting block and nod mounting block are supporting the support plate and configured to transmit vibrations of the foot rest assembly to the surface area of the support plate.

5) The foot rest assembly, as claimed in claim 1, wherein the foot support unit fixed on outer side of the holding cavity such that surface area of the support plate extends from a less dynamic response location to the highest dynamic response location.