US20040242378A1

US20040242378A1 - Passive shock absorber for treadmill

Info

Publication number: US20040242378A1
Application number: US10/447,107
Authority: US
Inventors: John Pan; Hung-Lung Uen; Shih-Huang Chu
Original assignee: Forhouse Corp
Current assignee: Forhouse Corp
Priority date: 2003-05-29
Filing date: 2003-05-29
Publication date: 2004-12-02

Abstract

A passive shock absorber for a treadmill includes a tall damping member and a short stopping member for supporting the tall damping member. Both the tall damping and the short stopping members have a top, a bottom and a spring stiffness, respectively. The tall damping and the short stopping member are combined together and are mounted in the treadmill. The passive shock absorbers are adapted to mount under a flat stationary member on which a person walks, runs or jogs. The top of the tall damping member abuts the flat stationary member. Consequently, the tall damping member can absorb impacts on the person's feet and the short stopping member will stop a compression of the tall damping member as the tall damping member is suddenly deformed and compressed.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a passive shock absorber for a treadmill, and more particularly to a simple passive shock absorber for a treadmill that will efficiently cushion impacts of and absorb impact forces on a runner's foot.

2. Description of Related Art

Treadmills are pieces of exercise equipment used by people to walk, run or jog in place. However, walking, running or jogging on the treadmill will impart impacts that will incur a possibility of a sport injury to the feet, ankles and knees to a person who is exercising on the treadmill. The impacts are caused by the force of the person's foot striking a flat stationary member, also called a deck, of the treadmill. The impacts on the person's foot must be reduced as the person runs, jogs or walks on the treadmill otherwise, the unattenuated impacts will cause the person who runs or jogs on the treadmill to feel uncomfortable and probably injure the person's feet, ankles or knees.

Therefore, to efficiently absorb or dissipate the impacts on the person's foot while running on the treadmill, passive shock absorbers are mounted in the treadmill to diminish effects of the impacts. A conventional passive shock absorber for a treadmill is a block of a damping material. Consequently, the conventional passive shock absorber only has a single spring stiffness and damping characteristic. However, different people using the treadmill will be of different weights and have different exercise preferences that cause different forces to strike the flat stationary member of the treadmill. The different forces will cause the impacts on the person's feet to have different magnitudes. The single spring stiffness and damping characteristics of the conventional passive shock absorber cannot dissipate the entire range of impacts caused by different people. In a worst condition, the unattenuated impacts will make the exerciser feel uncomfortable and even injure the person, as previously described.

To overcome the shortcomings, the present invention provides a passive shock absorber for a treadmill to mitigate or obviate the aforementioned problems.

SUMMARY OF THE INVENTION

The main objective of the invention is to provide a simple passive shock absorber for a treadmill to dissipate impacts caused by a person striking a flat stationary member of the treadmill as the person walks, runs or jogs on the treadmill.

The passive shock absorber is mounted in the treadmill below the flat stationary member and comprises a tall damping member and a short stopping member. Each of the tall damping and the short stopping members has a separate top, bottom, spring stiffness, shape and damping characteristic. The tall damping member is taller than the short stopping member. When a person runs on the treadmill, energies of the impacts on the person's foot will be absorbed or dissipated by the tall damping member of the passive shock absorber.

If the impact forces are so large that the tall damping member cannot absorb or dissipate all the energy in the impact, the tall damping member will be deformed and compressed whereafter the short stopping member will limit the compression of the tall damping member to prevent that from being completely deformed. Furthermore the short stopping member can also be made of viscoelastic material and will further absorb and attenuate the impacts when the tall damping member is entirely compressed. Under such a condition, the tall damping and the short stopping members cooperate with each other to absorb or dissipate the impacts on the person's feet.

Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a treadmill with multiple passive shock absorbers in accordance with the present invention; [0011]
FIG. 2 is an enlarged cross sectional side plan view of a passive shock absorber in FIG. 1 mounted in a treadmill; [0012]
FIG. 3 is a perspective view of the passive shock absorber in FIG. 2; [0013]
FIG. 4 is a perspective view of a second embodiment of a passive shock absorber in accordance with the present invention; [0014]
FIG. 5 is a perspective view of an alternative configuration of the passive shock absorber in FIG. 3; and [0015]
FIG. 6 is a perspective view of an alternate configuration of the second embodiment of the passive shock absorber in FIG. 4.[0016]

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

With reference to FIG. 1, a treadmill is conventional comprises a tread frame assembly ([0017] 10) and a front support (20). The tread frame assembly (10) comprises a tread frame (11) and a moving tread assembly (12). The tread frame (11) has a top (not numbered), a bottom (not numbered), a front (not numbered), a rear (not numbered) and two opposite sides (not numbered). Multiple transverse rods (111) are mounted between the sides of the tread frame (11) for passive shock absorbers (30) being mounted in the treadmill. For illustration purposes, only one transverse rod (111) is shown in FIG. 1. Each transverse rod (111) has a top (not numbered) and two ends (not numbered) respectively attached to the opposite sides of the tread frame (11).
The moving tread assembly ([0018] 12) is mounted in the tread frame (11) and comprises a flat stationary member (121), a moving tread (122) and rollers (not shown). The rollers are mounted in the tread frame (11) respectively at the front 11 and the rear. The flat stationary member (121) is mounted on the top of the tread frame (11) between the rollers in the tread frame (11) and has a top (not numbered) and a bottom (not numbered). The moving tread (122) is a wide endless belt and is mounted around the rollers and the flat stationary member (121) to form a flat moving surface (not numbered) on the top of the flat stationary member (121). A person can walk, run or jog in place on the flat moving surface of the moving tread (122) because the moving tread (122) rotates around the rollers.
Multiple passive shock absorbers ([0019] 30) in accordance with the present invention are mounted on the top of each transverse rod (111) under the bottom of the flat stationary member (121). However, positions of the passive shock absorbers (30) in the tread frame (11) are not limited to the disclosed embodiment. Such a statement means the passive shock absorbers (30) can be mounted at the sides of the tread frame (11) or other positions below the bottom of the flat stationary member (121).
With reference to FIGS. 2 and 3, each passive shock absorber ([0020] 30) comprises a tall damping member (31) and a short stopping member (32). Both the tall damping and the short stopping members (31, 32) respectively have both elasticity, regarded as spring stiffness, and a damping characteristic, regarded as a damping coefficient. The short stopping member (32) is cylindrical and has an axial center (not numbered), a top (not numbered), a bottom (not numbered), an outer periphery (not numbered) and a height. A mounting hole (33) is defined axially from the top to the bottom of the short stopping member (32). The tall damping member (31) is cylindrical and has a top (not numbered), a bottom (not numbered), an axial through hole (not numbered) and a height. The axial through hole of the tall damping member (31) is defined through the top of which. The outer periphery of the short stopping member (32) is received in the axial through hole of the tall damping member (31). The bottoms of both of the tall damping and the short stopping members (31, 32) are flush with each other and are mounted against the top of the transverse rod (111) in the tread frame (11). The passive shock absorber (30) is securely mounted in the treadmill between the transverse rod (111) and the flat stationary member (121) by a fastener (21). The fastener (21) has an enlarged end (not numbered) and a threaded end (not numbered). The threaded end passes through the flat stationary member (121) and the mounting hole (33) and screws into the transverse rod (111). The height of the tall damping member (31) is taller than the height of the short stopping member (32). Consequently, only the top of the tall damping member (31) initially abuts the bottom of the flat stationary member (122).
The tall damping member ([0021] 31) is made of viscoelastic material. The short stopping member (32) is made of a hard substance or viscoelastic material. Examples of viscoelastic materials and devices include rubber, plastic, cork, metal springs and pneumatic springs. Examples of the hard substance include hard rubber (an elastomer), plastic with a high rigidity or the like. The spring stiffness of the tall damping member (31) is larger than the spring stiffness of the short stopping member (32), which means the tall damping member (31) is softer than the short stopping member (32).
Consequently, the impacts on a person's foot will be transmitted to the tall damping members ([0022] 31) when the person is walking, running or jogging on the flat moving surface of the tread frame (11). Energy from the impact will be absorbed or dissipated by the tall damping member (31). If the impacts are too large, the tall damping member (31) will be deformed and compressed. The hard short stopping member (32), supporting the tall damping member (31), will limit a compression of the tall damping member (31) to prevent that from being completely deformed. Furthermore, if the short stopping member (32) is made of viscoelastic material, the tops of both of the tall damping and the short stopping members (31, 32) will abut the bottom of the flat stationary member (121) as the tall damping member (31) is entirely deformed. Both the tall damping and the short stopping members (31, 32) cooperate with each other to absorb or dissipate efficiently the large impacts on the person's feet. Therefore, the impacts on the person's feet are significantly absorbed and only a few greatly attenuated impacts will be transmitted in a diminished form to the person's foot. Thus, the passive shock absorber (30) can allow the person walking, running or jogging on the treadmill to feel comfortable and not be injured by the impacts.
With reference to FIG. 4, a second embodiment of a passive shock absorber ([0023] 40) in accordance with the present invention has the same inventive features as the previously described embodiment except for the arrangement of the tall damping and the short stopping members (31, 32). The second embodiment of passive shock absorber (40) in accordance with the present invention comprises a tall damping member (41) and a short stopping member (43). The tall damping member (41) is cylindrical and has an axial center, a top (not numbered), a bottom (not numbered), an outer periphery (not numbered) and a height. A mounting hole (42) is defined axially from the top to the bottom of the tall damping member (41). The short stopping member (43) is cylindrical and has a top (not numbered), a bottom (not numbered), an axial through hole (not numbered) and a height. The axial through hole of the short stopping member (43) is defined through the top of which. The outer periphery of the tall damping member (41) is received in the axial through hole of the short stopping member (43), with the bottoms of the members (41,43) being flush with each other. The tall damping and the short stopping members (41, 43) are made of previously described materials. The spring stiffness of the tall damping member (41) is larger than the spring stiffness of the short stopping member (43), which means the tall damping member (41) is softer than the short stopping member (43).
Therefore, the structure and characteristics of the second embodiment of the passive shock absorber ([0024] 40) are equivalent to the structure and features of the previously described passive shock absorber (30), and the mounting and operation of the second embodiment of the passive shock absorber (40) is the same as the previously described passive shock absorber (30). Therefore, further description is omitted.
With reference to FIGS. 5 and 6, the passive shock absorbers in accordance with the present invention can also be implemented to have the essential characteristics of the first and second embodiments of the passive shock absorbers ([0025] 30, 40) in the foregoing description while changing the shapes of the tall damping and the short stopping member (31, 32, 41, 43).
With reference to FIG. 5, a third embodiment of a passive shock absorber ([0026] 50) comprises a short stopping member (51) and two tall damping members (53). The short stopping member (51) is a rectangular parallelepiped with two opposite long sides (not numbered) instead of the cylindrical first embodiment of the short stopping member (32). Two tall damping member (53) are also rectangular parallelepiped instead of being cylindrical as is the first embodiment of the tall damping member (31). The tall damping members (53) are attached respectively to the long sides of the short stopping member (51). A mounting hole (52) is formed through the short stopping member (51) that is used to attach the passive shock absorber (50) in a manner similar to the previous embodiments of the passive shock absorber.
With reference to FIG. 6, a fourth embodiment of a passive shock absorber ([0027] 60) is a complementary version of the third embodiment and comprises a tall damping member (61) and two short stopping members (63). The tall damping member (61) is rectangular parallelepiped with two opposite long sides (not numbered) instead of the cylindrical second embodiment of the tall damping member (41). Two short stopping members (63) are also rectangular parallelepiped instead of being cylindrical as is the second embodiment of the short stopping member (43). The short stopping members (63) are attached to the long sides of the tall damping member (61). A mounting hole (62) formed through the tall damping member (61) that is used to attach the passive shock absorber (60) in a manner similar to the previous embodiments of the passive shock absorber.
The passive shock absorber is simple which results in the passive shock absorber being cheap and easy to manufacture. Because the tall damping and the short stopping members have different spring stiffnesses and damping characteristics, the passive shock absorber will absorb a wide range of impacts and minimize the effect of the impacts on the person's feet. Thereafter, the passive shock absorbers will allow an exerciser to feel comfortable when walking, running or jogging on the treadmill and prevent the person from being injured by the impacts. [0028]
Even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. [0029]

Claims

What is claimed is:

1. A passive shock absorber for a treadmill having a tread frame and a moving tread assembly, the moving tread assembly having a flat stationary member with a bottom, and the passive shock absorber adapted to be mounted between the thread frame and the bottom of the flat stationary member and comprising:

at least one tall damping member having a spring stiffness, a damping characteristic, a top, a bottom and a height and the at least one tall damping member being for dissipating impact energy on a person's feet; and

at least one short stopping member combined with the at least one tall damping member together and the at least one short stopping member having a spring stiffness, a damping characteristic, a top, a bottom and a height and the at least one short member being for stopping a compression of the at least one tall damping member;

wherein the spring stiffness of the at least one tall damping member is larger than the spring stiffness of the at least one short stopping member and the height of the at least one tall damping member is greater than the height of the at least one short stopping member.

2. The passive shock absorber as claimed in claim 1, wherein the at least one short stopping member is made of viscoelastic material for dissipating impact energy on the person's feet as the top of the at least one short stopping member abuts the bottom of the flat stationary member.

3. The passive shock absorber as claimed in claim 1, wherein the passive shock absorber has

one tall damping member having a cylindrical shape, an axial center and an outer periphery; and

one short stopping member attached to the outer periphery of the tall damping member and having a cylindrical shape and an axial through hole, the outer periphery of the tall damping member being received in the axial through hole of the short stopping member.

4. The passive shock absorber as claimed in claim 1, wherein the passive shock absorber has

one tall damping member having a rectangular parallelepiped shape with two opposite long sides; and

two short stopping members respectively attached to the long sides of the tall damping member, each short stopping member having a rectangular parallelepiped shape and attached to a corresponding one of the long sides of the tall damping member.

5. The passive shock absorber as claimed in claim 1, wherein the passive shock absorber has

one short stopping member having a cylindrical shape, an axial center and an outer periphery; and

one tall damping member attached to the outer periphery of the short stopping member and having a cylindrical shape and an axial through hole, the outer periphery of the short stopping member being received in the axial through hole of the tall damping member.

6. The passive shock absorber as claimed in claim 1, wherein the passive shock absorber has

one short stopping member having a rectangular parallelepiped shape with two opposite long sides; and

two tall damping members respectively attached to the long sides of the short stopping member, each tall damping member having a rectangular parallelepiped shape and attached to a corresponding one of the long sides of the short stopping member.

7. The passive shock absorber as claimed in claim 3, wherein a mounting hole is axially defined through the top to the bottom of the tall damping member.

8. The passive shock absorber as claimed in claim 4, wherein a mounting hole is defined through the top to the bottom of the tall damping member.

9. The passive shock absorber as claimed in claim 5, wherein a mounting hole is axially defined through the top to the bottom of the short stopping member.

10. The passive shock absorber as claimed in claim 6, wherein a mounting hole is defined through the top to the bottom of the short stopping member.