TREADMILL

Abstract

A treadmill includes a caterpillar track includes two belts, planks, caster-supporting elements, and casters. Each of the belts is a loop. Each of planks includes two terminal sections each of which is connected to an external face of a corresponding one of the belts. Each of the caster-supporting elements is connected to an internal face of a corresponding one of the belts. Each of the belts includes sections each of which is sandwiched between a corresponding one of the terminal sections of a corresponding one of the planks and a corresponding one of the caster-supporting elements. The casters are supported by the caster-supporting elements.

Description

BACKGROUND OF INVENTION

1. Field of Invention

The present invention relates to an exercise machine and, more particularly, to a compact, quiet and smooth treadmill.

2. Related Prior Art

A conventional treadmill includes a caterpillar track supported by a base. The caterpillar track includes two belts, treads and casters. Each of the belts is in the form of a loop. The treads are connected to external faces of the belts. Two axles are connected to each of two opposite ends of each of the treads. A caster is supported by each of the axles. The base includes two rails. Two casters connected to each of the ends of each of the treads are support by a corresponding one of the rails, thereby preventing the treads from flipping on the rails.

However, there are problems with the treadmill. The casters are connected to the ends of the treads. The rails are located beyond the treads accordingly. However, this renders the treadmill huge, heavy and expensive.

Moreover, each of the casters is equipped with a bearing including hard balls such as metal balls. The balls inevitably make annoying noises when the casters roll on the rails.

Furthermore, in use, an upper section of the caterpillar track trends to dangling above the rails and a lower section of the caterpillar track fluctuates below the rails. The movement of the caterpillar track relative to the rails is not smooth.

The present invention is therefore intended to obviate or at least alleviate the problems encountered in the prior art.

SUMMARY OF INVENTION

It is an objective of the present invention to provide a compact treadmill.

To achieve the foregoing objective, the treadmill includes a caterpillar track includes two belts, planks, caster-supporting elements, and casters. Each of the belts is a loop. Each of planks includes two terminal sections each of which is connected to an external face of a corresponding one of the belts. Each of the caster-supporting elements is connected to an internal face of a corresponding one of the belts. Each of the belts includes sections each of which is sandwiched between a corresponding one of the terminal sections of a corresponding one of the planks and a corresponding one of the caster-supporting elements. The casters are supported by the caster-supporting elements.

It is another objective of the present invention to provide a quiet treadmill.

To achieve the foregoing objective, the treadmill further includes two upper pads respectively extending on two upper rails. The upper pads are in contact with the casters connected to the upper section of the caterpillar track.

It is still another objective of the present invention to provide a smooth treadmill.

To achieve the foregoing objective, the treadmill further includes two limiting elements in addition to two lower pads. The lower rails support the casters connected to the lower section of the caterpillar track. Each of the limiting elements extends between a corresponding one of the upper rails and a corresponding one of the lower rails. Each of the limiting elements is used to abut against an upper portion of a corresponding one of the casters connected to the lower section of the caterpillar track.

Other objectives, advantages and features of the present invention will be apparent from the following description referring to the attached drawings.

BRIEF DESCRIPTION OF DRAWINGS

The present invention will be described via detailed illustration of the preferred embodiment referring to the drawings wherein:

FIG. 1 is a perspective view of a treadmill according to the preferred embodiment of the present invention;

FIG. 2 is an exploded view of a tread, two wheels and two wheel-supporting elements of the treadmill shown in FIG. 1;

FIG. 3 is a cross-sectional view of the treadmill shown in FIG. 1;

FIG. 4 is another cross-sectional view of the treadmill shown in FIG. 1; and

FIG. 5 is an enlarged partial view of the treadmill shown in FIG. 1.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

Referring to FIG. 1, a treadmill 10 includes a base 11 that supports a caterpillar track 14 according to the preferred embodiment of the present invention. The base 11 includes two shells 12 on two opposite sides of a frame 13.

Referring to FIGS. 3 and 5, the frame 13 includes at least one crossbar 33, two lateral beams 34, two upper rails 35, two lower rails 37 and two limiting elements 39. The lateral beams 34 are located between the shells 12. The crossbar 33 is supported by the lateral beams 34 so that the former is substantially located between the latter.

The upper rails 35 are connected to the lateral beams 34 by welding for example. Each of the upper rails 35 is located between a corresponding one of the lateral beams 34 and a corresponding one of the shells 12. That is, each of the upper rails 35 is located on an external side of the corresponding one of the lateral beams 34. Each of the upper rails 35 is arched, with two ends located higher than a middle point. An upper face of each of the upper rails 35 is covered by or coated with an upper pad 36.

Similarly, each of the lower rails 37 is connected to an external side of a corresponding one of the lateral beams 34, below a corresponding one of the upper rails 35. The lower rails 37 are arched. An upper face of each of the lower rails 37 is covered by or coated with a lower pad 38.

Each of the limiting elements 39 is formed with a connective portion 40 extending vertically. The connective portion 40 of each of the limiting elements 39 is connected to an external side of a corresponding one of the lateral beams 34, between a corresponding one of the upper rails 35 and a corresponding one of the lower rails 37. With the use of the connective portion 40, each of the limiting elements 39 extends from the external side of the corresponding one of the lateral beams 34, between the corresponding one of upper rails 35 and the corresponding one of the lower rails 37.

Referring to FIG. 1 again, the caterpillar track 14 includes two belts 15, planks 16, caster-supporting elements 20, axles 28, and casters 30. Each of the belts 15 is in the form of a loop. Each of the belts 15 includes two sections. Each of the sections is formed with an internal face pointed at the internal face of the remaining one of the sections. Each of the planks 16 includes a section connected to an external face of a corresponding one of the belts 15. Each of the caster-supporting elements 20 is connected a corresponding one of the planks 16, with a corresponding one of the belts 15 sandwiched between them. Each of the casters 30 is connected to a corresponding one of the caster-supporting elements 20.

Referring to FIG. 2, each of the planks 16 includes an elastic element 17 made of metal for example, a rigid element 18 made of thermoplastic elastomer (“TPE”) for example, and four threaded bolts 19. The four threaded bolts 19 are divided into two groups. Each of the groups of threaded bolts 19 is inserted in a corresponding one of two terminal sections of the rigid element 18. Each of the threaded bolts 19 includes an enlarged end abutting against a first face of the rigid element 18 and another end extending beyond a second face of the same. The elastic element 17 covers the first face of the rigid element 18 and the enlarged ends of the threaded bolts 19, thereby preventing the threaded bolts 19 from hindering a person using the treadmill.

Preferably, each of the caster-supporting elements 20 includes a top portion 21, a wall 22, and two reinforcing portions 23. The wall 22 extends from the top portion 21. Each of the reinforcing portions 23 is a triangular plate including an edge connected to the top portion 21 and another edge connected to the wall 22, thereby reinforcing each of the caster-supporting elements 20.

The wall 22 is formed with a cavity 25 in an external side, an annular protuberance 24 around the cavity 25, a bore 27 in an external side, and an annular protrusion 26 around the bore 27. The cavity 25 is in communication with the bore 27. The cavity 25 is a non-circular such as hexangular. The bore 27 is circular.

Each of the belts 15 is divided into sections. Each of the sections of each of the belts 15 is sandwiched between a corresponding one of the planks 16 and the top portion 21 of a corresponding one of the caster-supporting elements 20.

Each of the threaded bolts 19 further extends through a corresponding one of the planks 16 and the top portion 21 of a corresponding one of the caster-supporting elements 20. Then, each of the threaded bolts 19 is engaged with a nut 32 after, thereby connecting the caster-supporting elements 20 and the planks 16 to the belts 15.

Each of the axles 28 is a threaded bolt formed with an enlarged end 29. Each of the axles 28 is engaged with a nut 31 before insertion in the cavity 25 of a corresponding one of the caster-supporting elements 20 and a central aperture of a corresponding one of the casters 30. Thus, each of the casters 30 is supported by a corresponding one of the axles 28, which is supported on a corresponding one of the caster-supporting elements 20. The enlarged end 29 of each of the axles 28 is a hexangular one fitted in the cavity 25, thereby preventing rotation of each of the axles 28 relative to the corresponding one of the caster-supporting elements 20.

Each of the casters 30 is preferably a ball bearing that includes balls (nut numbered) between an external ring (nut numbered) and an internal ring (not numbered). The internal ring of each of the casters 30 is sandwiched between the annular protrusion 26 of the corresponding one of the caster-supporting elements 20 and a corresponding one of the nuts 31.

Referring to FIGS. 3 through 5, supported by the frame 13, the caterpillar track 14 remains in the middle of the base 11. The caterpillar track 14 is a loop including an upper half extending above the base 11 and a lower half facing a floor (not shown). The planks 16, the caster-supporting elements 20 and the casters 30 of the caterpillar track 14 are moved around frame 13 in operation.

Each of the upper pads 36 is L-shaped in a cross-sectional view. That is, each of the upper pads 36 is formed with a horizontal portion and a vertical portion.

Substantially half of the casters 30 are supported by the horizontal portions of the upper pads 36, which are supported by the upper rails 35. Thus, the horizontal portions of the upper pads 36 keep this substantially half of the casters 30 from the upper rails 35. The vertical portions of the upper pads 36 keep this substantially half of the casters 30 from the lateral beams 34. Hence, this substantially half of the casters 30 are movable along the upper rails 35 in silence.

Substantially half of the casters 30 are supported by the lower pads 38, which are supported by the lower rails 37. Thus, the lower pads 38 keep this substantially half of the casters 30 from the lower rails 37. Hence, this substantially half of the casters 30 are movable along the lower rails 37 in silence.

The limiting elements 39 limit the highest positions of lower half of the casters 30. Fluctuation of the lower halves of the caterpillar tracks 14 is limited because the lower half of the casters 30, which are connected to the lower halves of the caterpillar tracks 14, are confined between limiting elements 39 and the lower pads 38, which are coated on the lower rails 37.

The treadmill 10 exhibits advantageous features. Firstly, substantially upper half of the caster-supporting elements 20 are located below substantially upper half of the planks 16, and substantially lower half of the caster-supporting elements 20 are located above substantially lower half of the planks 16. This allows reduction of the width of the base 11 or the entire treadmill 10 while keeping the caterpillar track 14 as wide as those in the prior art.

Secondly, the pads 36 and 38 keep the casters 30 from the rails 35 and 37. Thus, the operation of the treadmill 10 is quieter than those in the prior art.

Thirdly, the cooperation of the limiting elements 39 with the lower rails 37 reduces the fluctuation of the substantially lower half of the caterpillar track 14 during the circulation or movement of the caterpillar track 14 around the frame 13. Thus, the circulation or movement of the caterpillar track 14 around the frame 13 is smooth.

The present invention has been described via the illustration of the preferred embodiment. Those skilled in the art can derive variations from the preferred embodiment without departing from the scope of the present invention. Therefore, the preferred embodiment shall not limit the scope of the present invention defined in the claims.

Claims

1. A treadmill comprising a caterpillar track comprising:

two belts in the form of a loop so that each of the belts comprises an internal face and an external face;

planks each of which comprises two terminal sections each of which is connected to the external face of a corresponding one of the belts;

caster-supporting elements each of which is connected to the internal face of a corresponding one of the belts, wherein each of the belts comprises sections each of which is sandwiched between a corresponding one of the terminal sections of a corresponding one of the planks and a corresponding one of the caster-supporting elements; and

casters supported by the caster-supporting elements.

2. The treadmill according to claim 1, wherein each of the caster-supporting elements comprises:

a top portion in contact with the internal face of the corresponding one of the belts while each of the planks is in contact with the external face of the corresponding one of the belts; and

a wall extending from the top portion, wherein the wall supports a corresponding one of the casters.

3. The treadmill according to claim 2, wherein each of the caster-supporting elements comprises two reinforcing portions each of which comprises a portion connected to the top portion and another portion connected to the wall.

4. The treadmill according to claim 2, wherein each of the caster-supporting elements further comprises an axle comprising a section connected to the wall and another section connected to the corresponding one of the casters.

5. The treadmill according to claim 4, wherein the axle comprises a non-circular enlarged end, wherein the wall comprises:

a non-circular cavity for receiving the non-circular enlarged end of the axle to prevent rotation of the axle relative to the wall; and

a bore via which another end of the axle extends to the corresponding one of the casters.

6. The treadmill according to claim 5, wherein the wall further comprises an annular protuberance around the cavity.

7. The treadmill according to claim 6, wherein the wall further comprises an annular protrusion around the bore, wherein the annular protrusion keeps the wall from the corresponding one of the casters.

8. The treadmill according to claim 1, further comprising a frame, wherein the caterpillar track extends around the frame and comprises an upper section above the frame and a lower section below the frame, wherein some of the casters are connected to the upper section of the caterpillar track, and wherein some others of the casters are connected to the lower section of the caterpillar track.

9. The treadmill according to claim 8, wherein the frame comprises:

two lateral beams extending between the upper and lower halves of the caterpillar track;

two upper rails respectively supported on the lateral beams; and

two upper pads respectively extending on the upper rails, wherein the upper pads are in contact with the casters connected to the upper section of the caterpillar track.

10. The treadmill according to claim 9, wherein the upper pad is L-shaped in a cross-sectional view.

11. The treadmill according to claim 9, wherein the upper pad is a flat one.

12. The treadmill according to claim 9, wherein the frame comprises:

two lower rails respectively supported on the lateral beams; and

two lower pads respectively extending on the lower rails, wherein the lower pads are in contact with the casters connected to the lower section of the caterpillar track.

13. The treadmill according to claim 12, wherein the lower pad is a flat one.

14. The treadmill according to claim 12, wherein the frame further comprises two limiting elements respectively supported on the lateral beams, wherein each of the limiting elements extends between a corresponding one of the upper rails and a corresponding one of the lower rails, and wherein each of the limiting elements is used to abut against an upper portion of a corresponding one of the casters connected to the lower section of the caterpillar track.

15. The treadmill according to claim 14, wherein each of the limiting elements comprises a connective portion extending vertically, wherein the connective portion is connected to a corresponding one of the lateral beams.