FIELD OF THE INVENTION
[0001] The present invention relates generally to an exercise or rehabilitation machine,
and more particularly to a device for providing the exercise or rehabilitation machine
with resistance.
BACKGROUND OF THE INVENTION
[0002] The conventional exercise or rehabilitation machine is generally provided with a
resistance device, which brings'about resistance by means of friction or oil pressure.
The friction-type resistance device is susceptible to wear and load unstableness,
which unable the device to control the magnitude of resistance with precision. The
oil pressure resistance device is vulnerable to oil leak and is rather noisy while
in operation.
SUMMRARY OF THE INVENTION
[0003] The primary objective of the present invention is to provide a device for effecting
resistance. The device of the present invention is free of the deficiencies of the
conventional devices described above.
[0004] In keeping with the principle of the present invention, the foregoing objective of
the present invention is attained by a resistance device which is designed for use
in an exercise or rehabilitation machine. The device of the present invention comprises
an excited magnetic cylinder, an excited magnetic coil, a rotary cylinder, and two
support frames. The excited magnetic coil is disposed in the excited magnetic cylinder
which is provided with a fixed shaft. The rotary cylinder is rotatably mounted on
the fixed shaft. The excited magnetic cylinder is provided in the periphery of the
midsegment thereof with an annular wavy interstice. The ridges of the wavy interstice
are provided with a projection which is used as a magnetic pole induction area. The
rotary cylinder is provided with a slot which is fitted over the magnetic pole induction
area. The eddy current induced by the rotary cylinder interacts with the magnetic
flux to bring about a rotation moment capable of an effective control of an arresting
wheel with precision.
[0005] The foregoing objective, features, and advantages of the present invention will be
more readily understood upon a thoughtful deliberation of the following detailed description
of a preferred embodiment of the present invention with reference to the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006]
FIG.1 shows an exploded view of the preferred embodiment of the present invention.
FIG. 2 shows a perspective view of the excited magnetic cylinder of the preferred
embodiment of the present invention.
FIG.3 shows a sectional view of the preferred embodiment of the present invention
in combination.
FIG.4 shows a perspective view of the preferred embodiment of the present invention
in combination.
FIG.5 shows a sectional view of the tooth of the excited magnetic cylinder of the
preferred embodiment of the present invention.
FIG.6 shows a schematic view of an exercise machine comprising the device of the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0007] As shown in FIGS. 1-5, a device embodied in the present invention comprises an excited
magnetic cylinder 10, an excited magnetic coil 20, a rotary cylinder 30, and two support
frames 40. The component parts of the device of the present invention are made of
a magnetically permeable material.
[0008] The excited magnetic cylinder 10 comprises a toothed disk 11 and a round toothed
cylinder 12. The toothed disk 11 is provided in the axial direction with a fixed shaft
113. Located between one side and the fixed shaft 113 are a shaft seat 111 and a protruded
ring 112 for locating the toothed cylinder 12. The toothed disk 11 is provided in
the fringe with a plurality of teeth 115, with each having a projected step 1151 and
an inclined plane 1152 serving as a current guiding surface. Located between the shaft
seat 111 and the fixed shaft 113 is an L-shaped through hole 114 through which a wire
21 of the excited magnetic coil 20 is put. The toothed cylinder 12 is provided at
one end with a plurality of ridges 121, with each having a projection 1211 and a slanted
surface 1212 serving as a magnetic field current guiding surface. The other end of
the toothed cylinder 12 is closed and is provided in the center with an axial hole
122 for fitting over the protruded ring 112 of the toothed disk 11.
[0009] The excited magnetic coil 20 is fixed on the shaft seat 111 such that the wire 21
of the excited magnetic coil 20 is put out of the fixed shaft 113 via the through
hole 114 to connect to a control switch C for effecting a stepless voltage adjustment
control.
[0010] The rotary cylinder 30 is provided with a round slot 31 which is in turn provided
with a plurality of ribs 32 arranged equidistantly, and a link shaft 33 which is provided
with an axial through hole 331 in communication with the round slot 31. The through
hole 331 is provided at both ends with a circular slot 332 for disposing a bearing
34.
[0011] The support frames 40 are of an L-shaped construction and are provided at the bottom
with a round hole 41 for fastening the support frames 40 with an exercise or rehabilitation
machine. The support frames 40 are further provided with a locating hole 42 for locating
the fixed shaft 113 of the toothed disk 11.
[0012] In combination, the excited magnetic coil 20 is mounted on the shaft seat 111 of
the toothed disk 11 of the excited magnetic cylinder 10 such that the wire 21 of the
magnetic coil 20 is connected to the control switch C and the power source via the
through hole 114 and the fixed shaft 113, as shown in FIGS. 3 and 6. The axial hole
122 of the toothed cylinder 12 of the excited magnetic cylinder 10 is fitted over
the protruded ring 112 of the shaft seat 11 such that the fringe of the excited magnetic
cylinder 10 is provided with a wavy interstice 13 toward which the magnetic lines
are guided. The circular slot 332 is provided with the bearing 34 for mounting the
rotary cylinder 30 on the fixed shaft 113 which is located in the locating hole 42
of the support frames 40.
[0013] The alternating current is made available to the excited magnetic coil 20 via a rectifier,
thereby resulting in formation of a closed loop magnetic field, with two sides of
the wavy interstice 13 serving as N/S poles for bringing about a magnetic field and
a magnetic flux, and with the inclined plane 1152 and the slanted surface 1212 serving
as the magnetic field current guiding surfaces. The fringes of the toothed disk 11
and the toothed cylinder 12 serve as the magnetic path, whereas the projected step
1151 and the projection 1211 serve as the magnetic path induction area. In light of
the gap between the slot wall 311 of the slot 31 of the rotary cylinder 30 and the
wavy interstice 13 of the excited magnetic cylinder 10, a magnetic resistance is brought
about between the rotary cylinder 30 and the excited magnetic cylinder 10.
[0014] As the rotary cylinder 30 is actuated by an external force to turn, the slot wall
311 of the slot 31 is moved continually past the induction areas of the projected
step 1151 and the projection 1211, thereby resulting in the eddy current which interacts
with the magnetic flux to bring about an action force acting on the rotary cylinder
30. It must be noted here that the gaps between the induction areas of the projected
step 1151 and the projection 1211 are not uniform in density in view of the fact that
the fringe of the slot 31 of the rotary cylinder 30 is provided with a plurality of
ribs 32.
[0015] As shown in FIG.6, the device of the present invention is incorporated into an exercise
machine such that the link shaft 33 of the rotary cylinder 30 of the device of the
present invention is linked with a belted wheel "W" of the exercise machine by a transmission
belt "T". The belted wheel "W" is in turn linked with an exercise wheel "R" of the
exercise machine. As soon as the device of the present invention is connected to the
power source, a predetermined voltage input is made available to the excited magnetic
coil 20 via the control switch C which is capable of a stepless voltage adjustment
control. The magnitude of resistance is dependent on the magnitude of the voltage
input that is made available to the excited magnetic coil 20. The induction areas
of the projected step 1151 and the projection 1211 serve as magnetic poles. When the
exercise wheel "R" is pedaled, the rotary cylinder 30 is actuated to turn to result
in the interaction of the magnetic flux and the eddy current between the induction
areas of the projected step 1151 and the projection 1211. The resistance can be then
transmitted to the exercise wheel "R" of the exercise machine via a transmission belt
linking the link shaft 33 of the rotary cylinder 30 with the belted wheel "W" (or
sprocket wheel) of the exercise machine.
[0016] The embodiment of the present invention described above is to be regarded in all
respects as being merely illustrative and not restrictive. Accordingly, the present
invention may be embodied in other specific forms without deviating from the spirit
thereof. The present invention is therefore to be limited only by the scopes of the
following appended claims.
1. A device for effecting resistance, said device being incorporated into an exercise
or rehabilitation machine such that a magnetic resistance of a closed loop magnetic
field effect is brought about at such time when the exercise or rehabilitation machine
is in operation, said device comprising an excited magnetic cylinder, an excited magnetic
coil, a rotary cylinder, and two support frames, said excited magnetic coil being
disposed in said excited magnetic cylinder which is provided in the fringe thereof
with an annular wavy interstice having two sides acting as N/S poles for bringing
about magnetic field, said two sides provided with a plurality of ridges, with each
having a projection serving as a magnetic pole induction area, said rotary cylinder
provided with a round slot having an annular wall contiguous to said wavy interstice,
said excited magnetic cylinder being provided in two sides with a fixed shaft being
located in a locating hole of said support frames, said excited magnetic cylinder
bringing about a closed loop magnetic field at the time when said excited magnetic
coil is connected to a power source, thereby causing a magnetic line to be guided
via said projections of said ridges, so as to bring about a magnetic resistance action
causing said excited magnetic cylinder and said rotary cylinder to attract each other.
2. The device as defined in claim 1, wherein said rotary cylinder is provided at one
end thereof with a round slot for fitting over said annular wavy interstice of said
excited magnetic cylinder such that an appropriate gap is formed, said round slot
being provided in the fringe with a plurality of ribs arranged equidistantly, said
rotary cylinder being provided at other end thereof with a link shaft for linking
said device with the exercise machine, said link shaft provided along the axial direction
thereof with a through hole in communication with said round slot, said through hole
provided at two ends thereof with a slot for disposing a bearing to facilitate said
through hole to be fitted over said fixed shaft of said excited magnetic cylinder
such that said rotary cylinder turns freely on said fixed shaft of said excited magnetic
cylinder.
3. The device as defined in claim 1, wherein said excited magnetic cylinder is formed
of a toothed disk and a toothed cylinder, said toothed disk being provided in the
axial direction thereof with a fixed shaft, a shaft seat and a protruded ring which
are located between said toothed disk and said fixed shaft, said toothed disk being
provided in the fringe with a plurality of teeth, with each having a projected step,
said shaft seat and said fixed shaft being provided with an L-shaped through hole
located therebetween for receiving a wire of said excited magnetic coil such that
said wire is connected to a power source, said toothed cylinder being provided at
one end with a plurality of ridges, with each having a projection, said toothed cylinder
being provided at other end with an axial hole which is fitted over said protruded
ring of said toothed disk, said toothed disk and said toothed cylinder enabling the
peripheral edge of said excited magnetic cylinder to have an annular wavy interstice.
4. The device as defined in claim 3, wherein said teeth of said toothed disk are provided
in the side of tooth edge thereof with an inclined plane serving as a current guiding
surface; wherein said ridges of said toothed cylinder are provided in the side of
tooth edge thereof with a slanted surface.
5. The device as defined in claim 1, wherein said rotary cylinder is connected to the
exercise machine such that said rotary cylinder turns synchronously with the exercise
machine in operation, and that said rotary cylinder provides the exercise machine
with a magnetic resistance.