BACKGROUND OF THEINVENTION1. Field of the InventionThe present invention relates to treadmill technology and more particularly, to a tread base for treadmill, which has two sliding tracks arranged on a tread base frame unit for supporting and guiding the movement of a movable sliding roller-equipped running belt to enhance the moving stability of the running belt, preventing breaking of slat components of the running belt and prolonging the lifespan of the tread base.
2. Description of the Related ArtUS2012/0010053A1 discloses a manually operated treadmill, which includes a treadmill frame having a front end and a rear end opposite the front end, a front shaft rotatably coupled to the treadmill frame at the front end, a rear shaft rotatably coupled to the treadmill frame at the rear end, and a running belt including a curved running surface upon which a user of the treadmill may run. The running belt is disposed about the front and rear shafts such that force generated by the user causes rotation of the front shaft and the rear shaft and also causes the running surface of the running belt to move from the front shaft toward the rear shaft. The treadmill is configured to control the speed of the running belt to facilitate the maintenance of the contour of the curved running surface.
However, this design of treadmill is still not satisfactory in function and has drawbacks as follows:
1. The running belt is comprised of a plurality of slat components; when the user is running on the running belt, the left and right bearing support frames supports the opposing left and right sides of the running belt, however, a large part of each slat component is suspended in the open air without support, and thus, the slat components can break easily upon a heavy impact force, causing accidents.
2. The bearings (non-sliding rollers) at the opposing left and right sides of the tread base frame unit are rotatable but not movable with the running belt, unable to enhance the moving smoothness of the running belt.
3. The left and right bearing support frames must be precisely processed to provide precision bearing holes for the mounting of respective bearings; if the machining tolerances of the bearing holes are slightly different, the sliding smoothness of the running belt can be reduced, leading to a defective product; the machining of the bearing holes and the installation of the bearings are complicated and need much labor and time, greatly increasing the manufacturing cost of the treadmill.
Further, the technique of using a conveyor belt to mate with belt wheels in a treadmill for enabling a runner to experience bumps and depressions when running is the known prior art technique. U.S. Pat. No. 1,211,765, U.S. Pat. No. 4,614,337, U.S. Pat. No. 5,470,293 and U.S. Pat. No. 5,577,598 disclose similar technical contents.
SUMMARY OF THE INVENTIONThe present invention has been accomplished under the circumstances in view. It is therefore the main object of the present invention to provide a tread base for treadmill, which has sliding tracks arranged on the tread base frame unit for supporting and guiding the movement of the movable sliding rollers of the running belt, enhancing the moving stability of the running belt.
It is another object of the present invention to provide a tread base for treadmill, which has sliding tracks arranged on the tread base frame unit for supporting and guiding the movement of the movable sliding rollers of the running belt, so that the impact force produced during running of the user on the running belt can be distributed through the movable sliding rollers of the running belt to the sliding tracks of the tread base frame unit, preventing breaking of the slats of the running belt, avoiding danger and prolonging the lifespan of the tread base.
It is still another object of the present invention to provide a tread base for treadmill, which facilitates the fabrication and installation of the movable sliding rollers and the sliding tracks without tedious precision dimensional tolerance proofreading works, saving much fabrication and installation labor and time and lowering the manufacturing cost.
BRIEF DESCRIPTION OF THE DRAWINGFIG. 1 is an oblique elevational view of a running belt of a tread base for treadmill in accordance with the present invention.
FIG. 2 is a side plain view of the running belt shown inFIG. 1.
FIG. 3 is an exploded view of the tread base frame unit and running belt of the tread base in accordance with the present invention.
FIG. 4 is an exploded view of the present invention, illustrating the tread base frame unit assembled with the front and bear belt wheel sets before mounting of the running belt.
FIG. 5 is an oblique elevational view of the tread base in accordance with the present invention.
FIG. 6 is a side plain view of the present invention, illustrating the running belt mounted around the main tread base frame of the tread base frame unit.
FIG. 7 is a schematic drawing of the present invention, illustrating the relationship between one slat and the respective movable sliding rollers in the respective sliding tracks.
FIG. 8 is a sectional end view ofFIG. 7.
DETAILED DESCRIPTION OF THE INVENTIONReferring toFIGS. 1-8, a tread base for treadmill in accordance with the present invention is shown. The tread base comprises:
a treadbase frame unit1, comprising a main tread base frame10 (seeFIG. 3 andFIG. 4) for holding a frontbelt wheel set2 and a rearbelt wheel set3 respectively at opposing front and rear sides thereof, aleft bracket12 and aright bracket13 respectively affixed to opposing left and right sides of the maintread base frame10 with fastening means or by welding;
a frontbelt wheel set2 comprising a front wheel axle21 (seeFIG. 3 andFIG. 4) transversely pivotally mounted in the front side of the maintread base frame10 and twofront belt wheels22 respectively mounted at opposing left and right ends of thefront wheel axle21;
a rearbelt wheel set3 comprising a rear wheel axle31 (seeFIG. 3 andFIG. 4) transversely pivotally mounted in the rear side of the maintread base frame10 and tworear belt wheels32 respectively mounted at opposing left and right ends of therear wheel axle31;
arunning belt4 seeFIGS. 1-4) comprising an endlesswide band belt41 mounted around the opposing front and rear sides of the maintread base frame10, a plurality ofslats42 respectively fixedly arranged around an outer perimeter of the endlesswide band belt41 in a parallel manner at a predetermined pitch, and two endlessnarrow band belts43 respectively fixedly fastened to an inner perimeter of the endlesswide band belt41 at opposing left and right sides and respectively coupled to therespective belt wheels22,32 of the front and rearbelt wheel sets2,3 so that when a user runs on theslats42 of therunning belt4, the endlesswide band belt41 and the endlessnarrow band belts43 are forced to move and to rotate thebelt wheels22,32 of the front, rearbelt wheel sets2,3;
wherein:
therunning belt4 further comprises at least one movablesliding roller44 mounted at each of opposing left and right ends of each slat42 (seeFIGS. 1-4 andFIG. 6);
the maintread base frame10 of the treadbase frame unit1 comprises two slidingtracks11 longitudinally arranged in parallel (seeFIGS. 3-4 andFIGS. 7-8) with respective twoopposite ends112 thereof smoothly downwardly curving toward a respectivelowest middle point111 to exhibit a smoothly arched profile for supporting and guiding the movablesliding rollers44 of therunning belt4 to enhance running stability.
Preferably, therunning belt4 further comprises a plurality ofpivot blocks45 respectively mounted at the opposing left and right ends of theslats42 to support the respective movablesliding rollers44.
Thus, when a user runs on theslats42 of therunning belt4 to move the endlesswide band belt41 and the endlessnarrow band belts43 and to rotate thebelt wheels22,32 of the front, rearbelt wheel sets2,3, the movablesliding rollers44 are rotated along the respective slidingtrack11 of the treadbase frame unit1, enhancing the stability of the movement of therunning belt4. At the same time, the impact force produced during running of the user is distributed through the movablesliding rollers44 of therunning belt4 to the slidingtracks11 of the treadbase frame unit1, preventing breaking of theslats42 of therunning belt4, avoiding danger and prolonging the lifespan of the tread base. Further, the fabrication and installation of the movablesliding rollers44 and the slidingtracks11 are simple and convenient without tedious precision dimensional tolerance proofreading works, saving much fabrication and installation labor and time and lowering the manufacturing cost.
In general, the invention achieves the effects as follows:
1. The slidingtracks11 are smoothly arched to support and guide the movablesliding rollers44 during movement of therunning belt4, enhancing the moving stability of therunning belt4.
2. The impact force produced during running of the user can be distributed through the movablesliding rollers44 of therunning belt4 to the slidingtracks11 of the treadbase frame unit1, preventing breaking of theslats42 of therunning belt4, avoiding danger and prolonging the lifespan of the tread base, further, the fabrication and installation of the movablesliding rollers44 and thesliding tracks11 are simple and convenient without tedious precision dimensional tolerance proofreading works, saving much fabrication and installation labor and time and lowering the manufacturing cost.