CROSS-REFERENCE TO RELATED APPLICATIONThis application claims priority of Taiwanese Application No. 095112453, filed on Apr. 7, 2006.
BACKGROUND OF THE INVENTION1. Field of the Invention
This invention relates to an elliptical exercise apparatus, more particularly to an elliptical exercise apparatus which is adjustable to provide a satisfactory elliptical path for suiting different operators.
2. Description of the Related Art
A conventional elliptical exercise apparatus generally includes footrests which are affixed to footrest shafts that perform a reciprocating movement by means of swinging of swing rods. Thus, during operation, only a limited elliptical route of the footrests can be achieved. As a result, the operator cannot obtain a sufficient amount of exercise, and cannot exercise with comfort. In a Taiwanese Utility Model Patent No. M282705 filed by the applicant, there is disclosed an elliptical exercise apparatus, which includes footrests that are slidable along guide rails when the footrests move along an elliptical route so as to permit the operator's feet to stretch sufficiently and to enable the operator to work out smoothly and comfortably. However, it is desirable to improve the elliptical exercise apparatus so that the elliptical route of the footrests is adjustable to meet different exercising requirements, and the span between the footrests is adjustable to suit different operators.
SUMMARY OF THE INVENTIONThe object of the present invention is to provide an elliptical exercise apparatus which can meet different exercising requirements and suit different operators.
According to this invention, the elliptical exercise apparatus includes a main frame, a crank assembly, a pair of swing rods, a pair of couplers, a pair of locking units, and a treadle assembly. The main frame includes a base support adapted to be supported on a supporting surface and having front and rear ends, and an upstanding support connected to the front end of the base support. The crank assembly includes a crank pin which defines a rotating axis, and which is mounted on the rear end of the base support, and a pair of crank shafts which are disposed diametrically opposite to each other relative to the rotating axis. Each of the swing rods has a swing fulcrum pivotally connected to the upstanding support, and handle and lever portions disposed respectively at upper and lower opposite sides of the swing fulcrum. The lever portion is swung about the swing fulcrum, and has a bottom end and a positioning segment disposed between the bottom end and the swing fulcrum. Each of the couplers is mounted on and is slidable along the positioning segment. Each of the locking units is disposed to arrest sliding movement of the respective coupler along the positioning segment. The treadle assembly includes a pair of guide rails, a pair of footrests, and a pair of linkages. Each of the guide rails has a rear rail end pivotally connected to the respective crank shaft, a front rail end pivotally connected to the respective couplers, and a middle rail portion interposed between the front and rear rail ends and disposed to perform a reciprocating movement when the lever portion is swung. The footrests are mounted on and are slidable along the middle rail portions of the guide rails, respectively, such that by virtue of the rotation of the crank shafts about the rotating axis, the footrests are alternately moved along reciprocating routes respectively. Each of the linkages has front and rear pivot ends that are respectively and pivotally connected to the bottom end and the respective footrest such that the footrests are moved alternately and respectively along elliptical paths.
BRIEF DESCRIPTION OF THE DRAWINGSOther features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment of the invention, with reference to the accompanying drawings, in which:
FIG. 1 is a schematic side view of the preferred embodiment of an elliptical exercise apparatus according to this invention;
FIGS. 2 and 3 are fragmentary sectional views of a portion of the preferred embodiment in which a coupler is at different height positions; and
FIG. 4 is a schematic view illustrating different swing paths of a swing rod of the preferred embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTReferring toFIGS. 1 and 2, the preferred embodiment of an elliptical exercise apparatus according to the present invention is shown to comprise amain frame1, acrank assembly6, a pair ofswing rods2, a pair ofcouplers31, a pair offirst locking units3, and atreadle assembly4.
Themain frame1 includes abase support11 which is adapted to be supported on a supporting surface, such as a ground surface, and which has front andrear ends111,112 opposite to each other in a longitudinal direction, and anupstanding support12 which is connected to thefront end111 of thebase support11.
Thecrank assembly6 includes awheel61 which has acrank pin62 that is mounted at a center thereof to define a rotating axis, and that is mounted on therear end112 of thebase support11 so as to be rotatable about the rotating axis, and a pair ofcrank shafts63 which are disposed adjacent to a rim of thewheel61, which are diametrically opposite to each other relative to the rotating axis, and which extend in a transverse direction relative to the longitudinal direction.
Each of theswing rods2 has aswing fulcrum21 which is pivotally connected to theupstanding support12, and handle andlever portions22,23 which are disposed respectively at upper and lower opposite sides of theswing fulcrum21. Thelever portion23 is swung about theswing fulcrum21, and has abottom end231 and apositioning segment232 which is disposed between thebottom end231 and theswing fulcrum21. Thepositioning segment232 of each of theswing rods2 has a plurality ofadjustment holes24 displaced from one another along a lengthwise axis thereof.
Each of thecouplers31 is in tubular shape, is sleeved on thepositioning segment232 so as to be slidable therealong, and has a throughhole311 which extends therethrough to be aligned with a selected one of theadjustment holes24.
Each of thefirst locking units3 includes afirst nut member321 which has a first tapped hole and which is disposed on a respective one of thecouplers31 so as to register the first tapped hole with the throughhole311, and afirst locking bolt32 which has a first threadedsegment323 that threadedly engages the first tapped hole, and afirst latch segment322 that is disposed to extend from the first threadedsegment323. By virtue of screw movement of the first threadedsegment323 in the first tapped hole, thefirst latch segment322 is movable to a locking position, where thefirst latch segment322 is inserted into a selected one of theadjustment holes24 so as to arrest a sliding movement of a respective one of thecouplers31 along thepositioning segment232.
Thetreadle assembly4 includes a pair ofguide rails41, a pair offootrests42, a pair oflinkages43, and a pair ofsecond locking units5. Each of theguide rails41 has arear rail end412 which is pivotally connected to a respective one of thecrank shafts63, afront rail end411 which is pivotally connected to a respective one of thecouplers31, and amiddle rail portion413 which is interposed between the front andrear rail ends411,412, and which performs a reciprocating movement when thelever portion23 of a respective one of theswing rods2 is swung. Thefootrests42 are mounted on and are slidable along themiddle rail portions413 of theguide rails41, respectively, such that by virtue of the rotation of thecrank shafts63 about the rotating axis, thefootrests42 are alternately moved along reciprocating routes respectively.
Each of thelinkages43 includes front and reartubular pieces431,432 which respectively have front andrear pivot ends435,436 that are respectively and pivotally connected to thebottom end231 of therespective swing rod2 and therespective footrest42 such that thefootrests42 are moved alternately and respectively along elliptical paths, and first and second connectedends437,438 which are telescopically fitted to each other so as to adjust a distance between the front and rear pivot ends431,432. The second connectedend438 of the reartubular piece432 has a plurality ofadjustment holes434 displaced from one another along a lengthwise axis thereof. The first connectedend437 of the fronttubular piece431 has a throughhole433 which extends therethrough to be aligned with a selected one of theadjustment holes434.
Each of thesecond locking units5, similar to thefirst locking unit3, includes asecond nut member51 which has a second tapped hole that is registered with the throughhole433, and asecond locking bolt50 which has a second threadedsegment53 that threadedly engages the second tapped hole, and asecond latch segment52 that extends from the second threadedsegment53 such that by virtue of screw movement of the second threadedsegment53 in the second tapped hole, thesecond latch segment52 is movable to be inserted into a selected one of theadjustment holes434 so as to arrest the movement of the first connectedend437 of the fronttubular piece431 relative to the second connectedend438 of the reartubular piece432.
When the operator stands on thefootrests42 with hands grasping thehandle portions22, and exerts a force on thefootrests42 in an alternating manner, theguide rails41, thelinkages43 and thecrank assembly6 move by virtue of the interconnections described above to result an elliptical motion of thefootrest42, thereby enabling in the operator's feet to travel along an elliptical route.
When the span between thefootrests42 is too small or large and makes the operator feel uncomfortable during exercising, thesecond locking bolts50 can be screwed out to disengage thesecond latch segments52 from theadjustment holes434 so as to permit movement of the secondtubular pieces432 along the lengthwise axis, and, the distance between the front andrear pivot ends435,436 can thus be adjusted to lengthen or shorten the sliding course of thefootrests42 on therespective guide rails41, thereby resulting in adjustment of the span between thefootrests42 as well as the span between the operator's feet.
With reference toFIGS. 3 and 4, when it is desired to increase or reduce the swing path (L1,L2) of theswing rods2 so as to lengthen or shorten the elliptical route, thefirst locking bolts32 are screwed out to an unlocking position, where thefirst latch segments322 are disengaged from theadjustment holes24 so as to permit movement of thecouplers31 along therespective positioning segments232. Thus, the front rail ends411 of theguide rails41 are movable upwardly or downwardly relative to theswing rods2. For example, when thefront rail ends411 is moved from point (A) to point (B), as shown inFIG. 4, a longer swing path (L2) is achieved so that a longer elliptical course can be obtained.
As illustrated, in the elliptical exercise apparatus of the present invention, the span between thefootrests42 and the elliptical paths of thefootrests42 can be adjusted to suit different operators.
While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is understood that this invention is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretations and equivalent arrangements.