RESISTANCE REGULATOR FOR A MAGNETIC BRAKE

Abstract

A resistance regulator for a magnetic brake includes a resistance-designating mark unit and an indicator, which can rotate relative to each other so as to move a pull rope that is adapted to be connected to the brake. The mark unit has a small-resistance mark and a plurality of equidistant large-resistance marks. The indicator is directed toward a selected one of the large-resistance and small-resistance marks. Each adjacent pair of the large-resistance marks are spaced apart from each other at a distance that is smaller than the distance between the small-resistance mark and a leading one of the large-resistance marks.

Description

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This invention relates to a resistance regulator, more particularly to a resistance regulator, which is connected to a magnetic brake by means of a pull rope that can move so as to adjust the magnitude of the resistance applied by the brake.

[0003] 2. Description of the Related Art

[0004] Referring to FIGS. 1 and 2, a conventional flywheel brake assembly for an exercise bike is shown to include a wheel shaft 1, and a flywheel 2 disposed fixedly around the wheel shaft 1 and disposed rotatably within a housing 2′. An aluminum ring 3 is fixed in the housing 2′. Two mounting plates 4 have upper ends 4′ that are mounted pivotally in the housing 2′ such that the mounting plates 4 can turn toward or away from each other. Each of the mounting plates 4 is provided with a plurality of fixed magnets 5 (only two are shown), and is biased by a spring 6, which is confined between the aluminum ring 3 and the respective mounting plate 4, to a position so that the magnets 5 are adjacent to an inner surface of the flywheel 2. Accordingly, the magnets 5 attract the flywheel 2 so as to provide a resistance to rotation of the flywheel 2, thereby functioning as a magnetic brake. When it is desired to reduce the resistance to the rotation of the flywheel 2, a pull rope 14 is drawn so as to move a movable piece 7 radially and inwardly in a radial slot 8 in the housing 2′ such that the mounting plates 4 rotate toward each other, thereby increasing the distance between the flywheel 2 and the magnets 5. When it is desired to increase the resistance to the rotation of the flywheel 2, the pull rope 14 is operated such that the magnets 5 are biased by the springs 6 to move toward the inner surface of the flywheel 2, thereby reducing the distance between the magnets 5 and the flywheel 2. FIG. 3 shows a conventional resistance regulator 10 for operating the pull rope 14, which includes an upper casing 11, a lower casing 12 that is connected fixedly to the upper casing 11, a vertical rotating shaft 13 journalled on the lower casing 12, and a reel 13′ sleeved non-rotatably on the rotating shaft 13. The pull rope 14 is wound around the reel 13′, and has one end that is fastened to the reel 13′, and another end that is coupled with the brake assembly such that the springs 6 (see FIG. 1) bias the pull rope 14 to unwind from the reel 13′. A rotary knob 15 is connected fixedly to the rotating shaft 13 so that rotation of the rotary knob 15 results in winding or unwinding of the pull rope 14 relative to the reel 13′. An indexing disc 161 is sleeved fixedly on the rotating shaft 13, and has an outer periphery with a serrated annular flange 164 that projects integrally and upwardly and that defines a plurality of positioning grooves 164′. A movable plate 162 is disposed movably relative to the upper and lower casings 11, 12, and is biased to move downwardly by a spring 163 so as to engage a downwardly extending integral tongue 165 of the movable plate 162 with a selected one of the positioning grooves 164′, thereby determining the magnitude of the resistance. As such, the magnets 5 (see FIGS. 1 and 2) can move toward the inner surface of the flywheel 2 (see FIGS. 1 and 2) step by step. To indicate the magnitude of the resistance, the resistance regulator 10 further includes a rotary disc 17 and a fixed disc 17′. The rotary disc 17 is sleeved fixedly on the rotating shaft 13, and has a circumferential face that is marked with six equidistant numerals “1” to “6”. The fixed disc 17′ is fixed on the lower casing 12, and has a top surface that is marked with six equidistant numerals “1” to “6”. A rotary knob 15 can be rotated about the fixed disc 17′ so that a triangular indicator 151 of the rotary knob 15 is aligned with a selected one of the numerals “1” to “6” on the fixed disc 17′. As such, the rotary disc 17 rotates relative to the upper casing 11 to a position, where a triangular indicator 111 of the upper casing 11 is aligned with a corresponding one of the numerals “1” to “6” on the rotary knob 17. The numerals “1” on the rotary disc 17 and the fixed disc 17′ represent zero resistance that means no magnetic attractive force is produced between the flywheel 2 (see FIG. 1) and the magnets 5 (see FIG. 1).

[0005] In a situation where the manufacturing precision of the brake assembly is comparatively low, it is likely that when the rotary knob 15 is rotated to a position, where the indicators 111, 151 are aligned with the numerals “2”, “3”, or even “4”, the brake assembly is still disposed at a zero resistance state. When the rotary knob 15 is rotated to move the top and side indicators 151, 11 between any adjacent pair of the numerals “1”, “2”, “3”, “4”, “5”, “6”, the magnets 5 (see FIGS. 1 and 2) move a constant small distance (L) (see FIG. 2). As a result, when the brake assembly is associated with the aforesaid resistance regulator 10, there is a need for a relatively high precision during manufacture and assembly of the magnetic brake in order to maintain effective adjustment of the regulator 10. Furthermore, it is difficult to read the numerals “1” to “6” for selection during resistance adjustment.

SUMMARY OF THE INVENTION

[0006] An object of this invention is to provide a resistance regulator which is connected to a magnetic brake by means of a pull rope and which has a resistance-designating mark unit and an indicator that cooperate with each other so that the regulator can adjusted effectively even if the manufacturing precision of the brake is comparatively low.

[0007] Another object of this invention is to provide a resistance regulator with a resistance-designating mark unit and an indicator, which cooperate with each other so that a selected resistance-designating mark can be read easily.

[0008] According to this invention, a resistance regulator for a magnetic brake includes a resistance-designating mark unit and an indicator, which can rotate relative to each other so as to move a pull rope that is adapted to be connected to the brake. The mark unit has a small-resistance mark and a plurality of equidistant large-resistance marks. The indicator is directed toward a selected one of the large-resistance and small-resistance marks. Each adjacent pair of the large-resistance marks are spaced apart from each other at a distance that is smaller than the distance between the small-resistance mark and a leading one of the large-resistance marks. As such, there is no need for high precision during the manufacture and assembly of the brake in order to maintain effective adjustment of the regulator.

[0009] In one preferred embodiment, the indicator is configured as a vertical line unit which is defined between a light-colored area and a deep-colored area of an outer surface of a rotary ring that is disposed rotatably on a base. The mark unit is formed on an outer surface of a surrounding wall of a cylindrical regulator body, which is fixed on the base. The surrounding wall is disposed around the rotary ring, and is formed with an elongated circumferentially extending window, within which the vertical line unit is visible. Because the deep-colored area is conspicuous in the window so that the vertical line unit can be seen clearly, the selected one of the large-resistance and small-resistance marks that is aligned with the vertical line unit can be read easily, thereby facilitating efficient adjustment of the resistance regulator. Alternatively, the mark unit can be formed from a white colorant, and is indicated on a transparent shield, which is fixed to the surrounding wall and which covers the window. Because the white mark unit is conspicuous in the deep-colored area, it can also be read easily.

[0010] In another preferred embodiment, the indicator is configured as a dark-colored area that is disposed between two light-colored areas and that is sized so that only a selected one of the large-resistance and smallresistance marks can be disposed therein. The darkcolored area is formed on an outer surface of a rotary ring which is disposed rotatably on a base and which is disposed within a surrounding wall of a cylindrical regulator body that is fixed on the base. The surrounding wall includes an elongated circumferentially extending window, within which the dark-colored area is movable, and a fixed transparent shield that covers the window. The mark unit is indicated on the shield, and is formed from a white colorant. As such, because the white colorant is conspicuous within the dark-colored area, it can be discerned easily.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] These and other features and advantages of this invention will become apparent in the following detailed description of the preferred embodiments of this invention with reference to the accompanying drawings, in which:

[0012] FIG. 1 is a schematic side view of a conventional flywheel brake assembly for an exercise bike, which is provided with a magnetic brake;

[0013] FIG. 2 is a sectional view of the conventional flywheel brake assembly;

[0014] FIG. 3 is an exploded perspective view of a conventional resistance regulator for the magnetic brake;

[0015] FIG. 4 is an exploded perspective view of a first preferred embodiment of a resistance regulator for a magnetic brake according to this invention;

[0016] FIG. 5 is a fragmentary sectional view of the first preferred embodiment, illustrating the relationships among a base, a hollow rotating shaft unit, and a cylindrical regulator body of the first preferred embodiment;

[0017] FIG. 6 is a fragmentary sectional view of the first preferred embodiment, illustrating a connection between a rotary knob and the base and a connection between the rotary knob and a rotary cap;

[0018] FIG. 7 is a top view of a ring plate of the first preferred embodiment, illustrating angular intervals of a plurality of positioning units;

[0019] FIG. 8 is a sectional view of a flywheel brake assembly, which is associated with the first preferred embodiment, illustrating how several magnets are moved toward a flywheel step by step;

[0020] FIG. 9 is a front view of the first preferred embodiment, illustrating the cooperation between a resistance-designating side mark unit and a side indicator which is configured as a vertical line unit that is movable within a window;

[0021] FIG. 10 is a view similar to FIG. 9, illustrating longitudinal movement of the vertical line unit in the window;

[0022] FIG. 11 is an assembled perspective view of the first preferred embodiment, illustrating the arrangement of a resistance-designating top mark unit with respect to a top indicator;

[0023] FIG. 12 is another assembled perspective view of the first preferred embodiment, illustrating the arrangement of the side mark unit with respect to the side indicator;

[0024] FIG. 13 is an assembled perspective view of a second preferred embodiment of a resistance regulator for a magnetic brake according to this invention, including a modified assembly of a side mark unit and a side indicator; and

[0025] FIG. 14 is a partly exploded perspective view of a third preferred embodiment of a resistance regulator for a magnetic brake according to this invention, illustrating another modified assembly of a side mark unit and a side indicator.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Referring to FIGS. 4, 5 and 6, a first preferred embodiment of a resistance regulator according to this invention is associated with a magnetic brake shown in FIG. 8, and is shown to include a base 20, a rotating shaft unit 30, a regulator body 40, a rotary knob 50, a rotary cap 60, and a ring plate 70.

[0027] The base 20 has an annular chamber 21, a fixed post 22 that extends upwardly therefrom and that is formed with a threaded hole 221, and a notch 23.

[0028] The rotating shaft unit 30 includes a hollow shaft body 31 that is sleeved rotatably on the post 22 of the base 20, a reel 32 that is sleeved fixedly on the shaft body 31, and a pull rope 33 that is fastened to the reel 32 at one end and that is coupled with the brake shown in FIG. 8 in a known manner at another end so as to be biased to unwind from the reel 32. The pull rope 33 extends outwardly from the base 20 via the notch 23. A rotary ring 34 is disposed fixedly around the shaft body 31 above the reel 32, and has an outer surface, which is formed with a deep-colored area 35 and a light-colored area 35′. In this embodiment, the deep-colored area 35 is deep red. A side indicator is disposed on the outer surface of the rotary ring 34, and is configured as a vertical line unit 35″ that is defined between the deep-colored area 35 and the light-colored area 35′. The shaft body 31 has a rectangular upper end 36.

[0029] The regulator body 40 is shaped as a hollow cylinder, and includes an open lower end, a top wall 40′, a surrounding wall 40″ extending downwardly from a periphery of the top wall 40′, and an elongated circumferentially extending window 41 formed in the surrounding wall 40″. The surrounding wall 40″ is disposed around the rotating shaft unit 30, and has a lower end that is fixed to the base 20 by known high-frequency welding techniques. A resistance-designating side mark unit 42 is disposed on an outer surface of the surrounding wall 40″, and includes two small-resistance marks and six large-resistance marks. The small-resistance and large-resistance marks are located immediately over the window 41. The small-resistance marks are configured as two numerals “1”, “2″. The large-resistance marks are configured as six numerals “3” to “8”, each adjacent pair of which are spaced apart from each other at a distance that is smaller than the distances between the numerals “1” and “2” and between the numerals “2” and “3”. The numerals “1” to “8” represent different resistances that increase in magnitude from “1” to “8”, respectively. A transparent shield 43 is fixed to the surrounding wall 40″ so as to cover the window 41. A minus mark “−” and a plus mark “+” are indicated on the outer surface of the surrounding wall 40″, and are located below and adjacent to the ends of the window 41. The top wall 401 is formed with two diametrically opposed restricting cavities 44, each of which receives a spring 45 and a ball 46 in such a manner the ball 46 is biased by the spring 45 to project partially and upwardly therefrom.

[0030] The rotary knob 50 includes a peripheral piece 501 that is formed with an external spline portion 51, and a central piece 52 that is fixed to the base 20 by means of a lock bolt 53, which extends through a central hole 521 in the central piece 52 to engage the threaded hole 221 in the post 22. The peripheral piece 50′ is sleeved rotatably on the central piece 52. A resistance-designating top mark unit 54 is disposed along a periphery of a top surface of the central piece 52, and includes two small-resistance marks and six equidistant large-resistance marks, which are configured as numerals “1” to “8”. In the top mark unit 54, each adjacent pair of the numerals “3” to “8” are spaced apart from each other at a distance that is smaller than both the distances between the numerals “1” and “2” and between the numerals “2” and “3”. The top mark unit 54 further includes a minus mark “−” 54″ that is disposed in front of the numeral “1” and that indicates the turning direction for decreasing the resistance during resistance adjustment, and a plus mark “+” 54″ that is disposed behind the numeral “8” and that indicates the turning direction for increasing the resistance during resistance adjustment. A top indicator 55 is disposed on a top surface of the peripheral piece 50′, and is configured as a triangular mark.

[0031] The rotary cap 60 is sleeved on the rotary knob 50, and is constructed as a hollow cylinder that has an open lower end, a transparent top wall 61, and an internal spline portion 62 that engages the external spline portion 51, thereby permitting synchronous rotation of the rotary cap 60 and the peripheral piece 50′.

[0032] The ring plate 70 is disposed between the regulator body 40 and the peripheral piece 50′, and has a peripheral portion with two positioning sets, each of which includes a zero-resistance positioning hole 71 that corresponds to the numerals “1” of the side and top mark units 42, 54, a first positioning unit that is shaped as a circular hole 72 and that corresponds to the numerals “2” of the side and top mark units 42, 54, six second positioning units that form cooperatively a slot 73 and that correspond respectively to the numerals “3” to “8” of the side and top mark units 42, 54, and a maximum-resistance designating hole 74. Each of the ring plate 70 and the peripheral piece 50′ has a rectangular hole 75, 56 (see FIG. 6), which engages fittingly the rectangular upper end 36 of the shaft body 31, thereby permitting synchronous rotation of the ring plate 70 and the peripheral piece 50′ with the shaft body 31.

[0033] Referring to FIG. 7, the slot 73 has two closed ends, and alternate wide and narrow portions 731, 732. Each of the wide portions 731 is generally oval. Each adjacent pair of the wide portions 731 are spaced apart angularly from each other at an angle of about 12°. The holes 71 and 72 are spaced apart angularly from each other at an angle of about 45°. The hole 72 is spaced apart angularly from a leading one of the wide portions 731 at an angle of about 21°.

[0034] FIG. 8 shows a flywheel brake assembly that is associated with the resistance regulator of this invention and that is coupled with the pull rope 33 (see FIG. 4) in a known manner. The flywheel brake assembly includes a rotating shaft 1″, a flywheel 2″, an aluminum ring 3″, two mounting plates 4″, and several magnets 5″.

[0035] Referring to FIGS. 4, 8, 9 and 10, when the rotary cap 60 is rotated so as to move the vertical line unit 35″ from the numeral “1” of the side mark unit 42 to the numeral “2”, the magnets 5″ move toward an inner surface of the flywheel 2″ by a distance (L1). When the vertical line 35″ moves from the numeral “2” to the numeral “3”, the magnets 5″ move toward the inner surface of the flywheel 2″ by a distance (L2) that is smaller than the distance (L1). When the vertical line 35″, moves between any adjacent pair of the numerals “3” to “8”, the magnets 5″ move relative to the flywheel 2″ by a distance (L3) that is smaller than the distance (L2). Because the distances (L1), (L2) are larger than the distance (L3), there is no need for high precision during the manufacture and assembly of the magnetic brake. Note that although there are two small-resistance marks on each of the side and top mark units 42, 54, one small-resistance mark is sufficient to achieve the object of this invention with respect to the manufacturing precision of the brake.

[0036] In FIGS. 11 and 12, the resistance regulator is adjusted to a second resistance, where the vertical line unit 35″ is aligned with the numeral “2” of the side mark unit 42 and where the top indicator 55 is aligned with the numeral “2” of the top mark unit 54. Because the deep-colored area 35 is conspicuous in the window 41, a selected one of the numerals “1”, “2”, “3”, “4”, “5”, “6”, “7”, “8” can be read easily.

[0037] FIG. 13 shows a second preferred embodiment of a resistance regulator according to this invention, which is similar to the first preferred embodiment in construction except for the position and the color of the side mark unit 42′. In this embodiment, the side mark unit 42′ is indicated on the transparent shield 43′, and is formed from a white colorant, which is conspicuous in the deep-colored area 35A.

[0038] FIG. 14 shows a third preferred embodiment of a resistance regulator according to this invention, which is similar to the second preferred embodiment in construction except for the side indicator 35A. In this embodiment, the side indicator 35A is configured as a dark-colored area that is disposed on the outer surface of the rotary ring 34′ between two light-colored areas 35B and that is movable in the window 41′ in a longitudinal direction of the window 41′. In this embodiment, the side indicator 35A is dark red, and is sized such that only the selected one of the numerals “1”, “2”, “3”, “4”, “5”, “6”, “7”, “8” can be disposed therein.

[0039] With this invention thus explained, it is apparent the numerous modifications and variations can be made without departing from the scope and spirit of this invention. It is therefore intended that this invention be limited only as indicated in the appended claims.

Claims

1. A resistance regulator for a magnetic brake, said regulator comprising:

a base with a fixed post extending upwardly therefrom;

a rotating shaft unit including

a hollow shaft body sleeved rotatably on said post,

a reel sleeved fixedly on said shaft body,

a pull rope wound around said reel and having one end that is fastened to said reel, and another end that is adapted to be coupled with the brake in such a manner that said pull rope is biased to unwind from said reel, and

a side indicator disposed fixedly on said shaft body and located above said reel so as to rotate about said shaft body;

a regulator body fixed on said base and including

a surrounding wall disposed around said rotating shaft unit,

a resistance-designating side mark unit disposed on said surrounding wall and having a small-resistance mark and a plurality of equidistant large-resistance marks which represent different resistance resistances that are larger than that of said small-resistance mark of said side mark unit, said small-resistance mark and said large-resistance marks of said side mark unit being arranged circumferentially on said surrounding wall, each adjacent pair of said large-resistance marks of said side mark unit being spaced apart from each other at a distance that is smaller than a distance between said small-resistance mark of said side mark unit and a leading one of said large-resistance marks of said side mark unit, said side indicator being directed toward a selected one of said large-resistance and small-resistance marks of said side mark unit so as to be adapted to indicate a resistance of the brake, and

a top wall with a spring-biased ball that is biased to project upwardly and partially therefrom;

a rotary knob unit including

a central piece mounted fixedly on said post of said base and having a top surface,

a resistance-designating top mark unit disposed on said top surface of said central piece and having a small-resistance mark and a plurality of equidistant large-resistance marks which represent different resistances that are larger than that of said small-resistance mark of said top mark unit, said small-resistance mark and said large-resistance marks of said top mark unit being arranged circumferentially on said top surface of said central piece and corresponding respectively to said small-resistance mark and said large-resistance marks of said side mark unit, each adjacent pair of said large-resistance marks of said top mark unit being spaced apart from each other at a distance that is smaller than a distance between said small-resistance mark of said top mark unit and a leading one of said large-resistance marks of said top mark unit,

a peripheral piece sleeved rotatably on said central piece and connected fixedly to said shaft body of said rotating shaft unit, said peripheral piece having a top surface, and

a top indicator fixed on said top surface of said peripheral piece and directed toward a selected one of said small-resistance and large-resistance marks of said top mark unit; and

a ring plate sleeved fixedly on said shaft body of said rotating shaft unit and having a first positioning unit and a plurality of second positioning units that correspond respectively to said small-resistance and large-resistance marks of said side and top mark units, said peripheral piece of said rotary knob being rotatable relative to said base and said regulator body so as to engage said spring-biased ball of said regulator body with a selected one of said first and second positioning units in said ring plate, thereby aligning said top and side indicators with corresponding ones of said small-resistance and large-resistance marks of said top and side mark units.

2. The resistance regulator as claimed in claim 1, further comprising a rotary cap, which is shaped as a hollow cylinder that has an open lower end and a transparent upper end wall and which is disposed around said peripheral piece, one of said peripheral piece and said rotary cap having an internal spline portion, the other one of said peripheral piece and said rotary cap having an external spline portion that engages said internal spline portion, thereby permitting synchronous rotation of said peripheral piece and said rotary cap.

3. The resistance regulator as claimed in claim 1, wherein each of said peripheral piece and said ring plate has a rectangular hole, said shaft body of said rotating shaft unit having a rectangular upper end that engages fittingly said rectangular holes in said peripheral piece and said ring plate, thereby preventing rotation of said peripheral piece and said ring plate relative to said shaft body.

4. The resistance regulator as claimed in claim 1, wherein said surrounding wall includes an elongated circumferentially extending window that is formed therethin, said rotating shaft unit including a rotary ring which is disposed fixedly around said shaft body and which has an outer surface that has a light-colored area and a deep-colored area, said light-colored area and said deep-colored area defining a vertical line unit therebetween that constitutes said side indicator and that is movable in said window in said surrounding wall in a longitudinal direction of said window when said peripheral piece rotates relative to said central piece, said surrounding wall having an outer surface, said large-resistance and small-resistance marks of said side mark unit being indicated on said outer surface of said surrounding wall and being located immediately over said window.

5. The resistance regulator as claimed in claim 4, wherein said regulator body further includes a transparent shield, which is fixed on said surrounding wall and which covers said window in said surrounding wall.

6. The resistance regulator as claimed in claim 4, wherein said ring plate further includes a leading positioning unit that is shaped as a circular hole, and a slot that has two closed ends and a plurality of alternate wide and narrow portions, said wide portions being wider than said narrow portions and constituting said second positioning units, respectively, said first positioning unit being located between said leading positioning unit and said second positioning units and being spaced apart angularly from said leading positioning unit at an angle of about 45°, each of said wide portions of said slots being generally oval, a leading one of said wide portions being spaced apart angularly from said first positioning unit at an angle of about 21°, each adjacent pair of said wide portions being spaced apart angularly from each other at an angle of about 12°.

7. The resistance regulator as claimed in claim 1, wherein said surrounding wall includes an elongated circumferentially extending window that is formed therein, and a transparent shield that is fixed to said surrounding wall and that covers said window, said rotating shaft unit including a rotary ring which is disposed fixedly around said shaft body and which has an outer surface that is formed with a deep-colored area and a light-colored area, said deep-colored area and said light-colored area defining a vertical line unit therebetween that constitutes said side indicator and that is movable in said window in said surrounding wall in a longitudinal direction of said window when said peripheral piece rotates relative to said central piece, each of said large-resistance and small-resistance marks of said side mark unit being formed from a white colorant and being indicated on said transparent shield.

8. The resistance regulator as claimed in claim 1, wherein said surrounding wall includes an elongated circumferentially extending window, which is formed therethin and which has two closed ends, and a transparent shield that is fixed to said outer surface of said surrounding wall and that covers said window, said rotating shaft unit including a rotary ring that is disposed fixedly around said shaft body and that has an outer surface, said side indicator being configured as a dark-colored area that is indicated on said outer surface of said rotary ring, said dark-colored area being movable in said window in said surrounding wall in a longitudinal direction of said window when said peripheral piece rotates relative to said central piece, so as to move a selected one of said large-resistance and small-resistance marks of said side mark unit into said dark-colored area.