GB2297132A

GB2297132A - A resistance device for an exercise machine

Info

Publication number: GB2297132A
Application number: GB9500930A
Authority: GB
Inventors: Minghwa Chern
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-01-18
Filing date: 1995-01-18
Publication date: 1996-07-24
Also published as: GB9500930D0

Abstract

A resistance device for an exercise machine includes a housing 10, an axle 20, a rotation member 30 connected with a helical spring 25, located on the axle, via a grub screw engaging in loop 26, a plurality of annular brake disks rotatable with the axle alternating with a plurality of annular brake linings non-rotatable relative to the housing. When the member 30 and shaft 31 are rotated clockwise relative to the housing, the spring tightens on the axle so that the axle is rotated against the resistance resulting from the engaging discs and linings. On counter-clockwise movement of the rotation member relative to the housing, the axle is not rotated. The resistance can be adjusted by a screw-operated wedging arrangement 45-47.

Description

DESCRIPTION OF THE INVENTION Resistance Device of an Exercise Machine This invention relates to a resistance device for an exercise machine.

Hydraulic cylinders have been used as resistance devices of exercise machines. However, leakage will occur in the hydraulic cylinders when they have been used for a certain period of time. Combinations of weights, ropes, pulleys and brackets have also been used as resistance devices of exercise machines. However, such combinations are complicated in structure, thus involving high costs.

Therefore, it is the primary objective of this invention to provide a resistance device including a housing including an internal surface, a plurality of ribs formed on the internal surface of the housing, an axle including an upper portion and a lower portion received in the housing, a rotation member connected with the upper portion of the axle so that the axle is rotated when the rotation member is rotated in a direction and that the axle is not rotated when the rotation member is rotated in an opposite direction, two straight surfaces formed on the lower portion of the axle, a plurality of annular brake disks each including an annular configuration defining an internal edge including two straight portions corresponding to the straight surfaces formed on the lower portion of the axle, a plurality of annular brake linings each including an external edge defining a plurality of cutouts corresponding to the ribs.

The annular brake disks and the brake linings are alternatively mounted on the lower portion of the axle. The straight portions of the internal edges of the annular brake disks are in engagement with the straight surfaces formed on the lower portion of the axle so that the annular brake disks are rotatable with the axle. The cutouts defined in the linings are in engagement with the ribs formed on the internal surface of the housing so that the linings are retained in position in the housing. There will be frictional forces between the annular brake disks and the brake linings when the axle is rotated.

The preferred embodiment of a resistance device of an exercise machine according to this invention will be described in detail with reference to the attached drawings in which: FIG. 1 is a perspective view of a resistance device of an exercise machine; FIG. 2 is an exploded partial view of the resistance device as shown in FIG 1; FIG. 3 is another exploded partial view of the resistance device as shown in FIG. 1; and FIG. 4 is a partial cross-sectional view of the resistance device as shown in FIG. 1.

Referring to FIG. 1, a resistance device includes a base 16, a lower cover 13, a housing 10, a collar 30 and an upper cover 34. The base 16 defines a plurality of apertures (not numbered) for receiving a corresponding number of bolts (not shown) for mounting the base 16 on an exercise machine (not shown). The lower cover 13 is pivotably mounted on the base 16. The housing 10 is sealed by means of the lower cover 13. The collar 30 is mounted on the housing 10 in such a way that there will be a resistance when the collar 30 is rotated in respect to the housing 10.

Details of the collar 30, the housing 10 and the base 16 will be described in detail at a later stage.

Referring to FIG. 3, the base 16 includes a disk and a hollow protrusion (not numbered) projecting from an upper side of the disk. Two slots (not numbered) are defined in the hollow protrusion of the base 16.

The lower cover 13 includes a disk and two lugs 14 projecting from a lower side of the disk. A number of apertures are defined in the lower cover 13. An aperture (not numbered) is defined in each of the lugs 14.

A threaded bolt 17 is inserted through the apertures defined in the tabs 14 of the base 13, the slots defined in the hollow protrusion of the base 16 and a plurality of washers (not numbered). Furthermore, the threaded bolt 17 is in engagement with a threaded nut (not numbered). The lower cover 13 is pivotably connected with the base 16 by means of the threaded bolt 17 and the threaded nut.

Referring to FIG. 2, the housing 10 includes an external surface and an internal surface. The external surface of the housing 10 is pressed at a plurality of rectilinear portions so as to form a plurality of ribs 11 on the internal surface of the housing 10. The housing 10 defines an aperture 12. The housing 10 includes a lower end portion and an upper end portion. An annular flange (not numbered) projects radially outwardly from the lower end portion of the housing 10. A number of apertures (not numbered) are defined in the annular flange formed on the lower end portion of the housing 10. An annular flange 15 projects radially inwardly from the upper end portion of the housing 10.

There is an axle 20 including an upper portion 21 and a lower portion 23. The diameter of the upper portion 21 is smaller than the diameter of the lower portion 22. A groove 22 is defined in the upper portion 21 of the axle 20. Two opposite portions of the lower portion 23 of the axle 20 are cut away, forming two straight surfaces 24.

Referring to FIG. 4, the upper portion 21 of the axle 20 is passed beyond the annular flange 15 while the lower portion 22 of the axle 20 is restrained by means of the annular flange 15, i.e., the lower portion 22 of the axle 20 is retained within the housing 10.

Referring to FIGS. 2 and 4, a ring 40 is received in the housing 10 50 that the ring 40 is in contact with the annular flange 15.

Referring to FIG. 3, each of two rigid annular members 41 (only one is shown) includes an external edge defining a plurality of cutouts 50 corresponding to the ribs 11.

There are a plurality of annular positioners 42 each including an external edge defining a plurality of cutouts 52 corresponding to the ribs 11. Each of the annular positioners 42 defines a plurality of separated slots 54.

A brake lining 43 is received in each of the slots 54 defined in each of the annular positioners 42. The brake linings 43 are made of recycled paper, thus, used brake linings 43 can be disposed of without causing a serious environmental problem.

There are a plurality of annular brake disks 44 each including an internal edge including two opposite straight portions 56 corresponding to the straight surfaces 24 (see FIG. 2).

The annular positioners 42 and the annular brake disks 44 are alternatively located between the rigid annular members 41. The rigid annular members 41, the annular positioners 42 and the annular brake disks 44 are mounted on the lower portion 22 of the axle 20. The ring 40 is in contact with an upper one of the rigid annular members 41 for keeping the rigid annular members 41, the annular positioners 42 and the annular brake disks 44 in a desired position.

The straight portions 56 of the internal edges of the annular brake disks 44 are in engagement with the straight surfaces 24 of the lower portion 22 of the axle 20. Thus, the annular brake disks 44 are rotatable with the axle 20.

The cutouts 50 and the cutouts 52 are in engagement with the ribs 11 thus preventing rotation of the rigid annular members 41, the annular positioners 42 and the brake linings 43 relative to the housing 10.

Referring to FIGS. 3 and 4, there is a first wedge 45 including a horizontal upper surface and an inclined lower surface in which two parallel channels 58 are defined. The first wedge 45 is received in the housing 10 so that the horizontal upper surface of the first wedge 45 is in contact with a lower one of the rigid annular members 41.

Two bars 47 are received in the channels 58.

There is a second wedge 46 including an inclined upper surface and a horizontal lower surface thus forming a thin portion and a thick portion. Two parallel channels 60 are defined in the inclined upper surface of the second wedge 46. Two parallel channels 62 are defined in the horizontal lower surface of the second wedge 46. A hole 64 is defined in the thick portion of the second wedge 46.

The second wedge 46 is received in the housing 10. The bars 47 are received in the channels 60.

Two additional bars 47 are received in the channels 62.

A number of threaded bolts (see FIG. 1) are inserted through the apertures defined in the annular flange formed on the lower end portion of the housing 10 and the apertures defined in the lower cover 13. The threaded bolts are in engagement with a corresponding number of threaded nuts (not shown), thus sealing the housing 10 by means of the lower cover 13.

A second threaded bolt 48 is inserted through the aperture 12 defined in the housing 10. The second threaded bolt 48 is in threaded engagement with the housing 10.

When the shaft 20 is forced to rotate in respect to the housing 10, the annular brake disks 44 slide between the brake linings 43, because the annular brake disks 44 are rotatable with the shaft 20 as mentioned above while the brake linings 43 are retained in position in the housing 10 as mentioned above. There are thus frictional forces between the brake linings 43 and the annular brake disks 44.

The second threaded bolt 48 is rotatable in respect to the housing 10, thus adjusting normal forces between the brake linings 43 and the annular brake disks 44 because of the engagement between the first wedge 45, the rods 47 and the second wedge 46. The frictional forces between the brake linings 43 and the annular brake disks 44 are adjustable as they are proportional to the normal forces between the brake linings 43 and the annular brake disks 44.

In the preferred embodiment, as the bars 47 are used for engagement between the first wedge 45 and the second wedge 46, the inclined lower surface of the first wedge 45 need not be flat, therefore, a space can be defined in the center of the first wedge 45 for reduction of weight.

Similar to the first wedge, a space can be defined in the center of the second wedge 46.

In the preferred embodiment, the bars 47 are used for easy sliding of the second wedge 46, however, the bars 47 can be omitted in another embodiment. In the situation where the bars 47 are omitted, the first wedge 45 cannot be annular because the first wedge 45 has to be in direct contact with the second wedge 46. In the situation where the first wedge 45 is not annular, a cavity should be defined in the upper surface thereof for receiving a lower end portion of the axle 20 when the first wedge 45 is moved upwards by means of the rotation of the threaded bolt 48.

Referring to FIGS. 2 and 4, a helical spring 25 is mounted on the upper portion 21 of the axle 20. The helical spring 25 includes a looped end portion 26.

The collar 30 includes a shaft 31 projecting therefrom and an aperture 32 defined therein. The shaft 31 is used for rotation of the collar 30. The collar 30 is mounted on the housing 10. A first threaded bolt 33 is inserted through the aperture 32. The first threaded bolt 33 is in threaded engagement with the collar 30. Furthermore, the first threaded bolt 33 is inserted through the looped end portion 26 of the spring 25. Thus, the helical spring 25 is rotatable with the collar 30. A tip of the first threaded bolt 33 is received in the groove 22. The upper cover 34 is mounted on the collar 30.

Referring to FIGS. 1 and 4, the helical spring 25 is rotated clockwise when the shaft 31 is pivoted clockwise so that the axle 20 is held tightly by means of the helical spring 25 so as to be rotated. There are frictional forces between the annular brake disks 44 and the brake linings 43 as the annular brake disks 44 are rotated while the brake linings 43 are restrained. The rotation of the shaft 31 is resisted.

The helical spring 25 is rotated counterclockwise when the shaft 31 is pivoted counterclockwise so that the axle 20 is released from the helical spring 25 so as not to be rotated. There is no frictional force between the annular brake disks 44 and the brake linings 43 as the annular brake disks 44 are not rotated. The rotation of the shaft 31 is not resisted.

Each of the annular brake disks 44 defines a plurality of apertures (not numbered) for dissipation of heat produced by the frictional forces between the annular brake disks 44 and the brake linings 43.

In the above embodiment, the annular positioners 42 are used to retain the linings 43 in position when the annular brake disks 44 because the brake linings 43 are flexible as the brake linings 43 are made from recycled paper. However, in another embodiment not shown, the annular positioners 44 can be omitted if brake linings are made rigid by means of processing under a high pressure. In this case, each of the brake linings includes an annular configuration including an external edge defining a plurality of cutouts corresponding to the ribs 11.

Claims

1. A resistance device comprising a housing including an internal surface, a plurality of ribs formed on the internal surface of the housing, an axle including an upper portion and a lower portion received in the housing, a rotation member connected with the upper portion of the axle so that the axle is rotated when the rotation member is rotated in a direction and that the axle is not rotated when the rotation member is rotated in an opposite direction, two straight surfaces formed on the lower portion of the axle, a plurality of annular brake disks each including an annular configuration defining an internal edge including two straight portions corresponding to the straight surfaces formed on the lower portion of the axle, a plurality of annular brake linings each including an external edge defining a plurality of cutouts corresponding to the ribs, the annular brake disks and the brake linings alternatively mounted on the lower portion of the axle, the straight portions of the internal edges of the annular brake disks being in engagement with the straight surfaces formed on the lower portion of the axle so that the annular brake disks are rotatable with the axle, the cutouts defined in the linings being in engagement with the ribs formed on the internal surface of the housing so that the linings are retained in position in the housing, whereby there will be frictional forces between the annular brake disks and the brake linings when the axle is rotated.

2. A resistance device according to claim 1 wherein the rotation device includes a collar, a shaft projecting from the collar, a helical spring mounted on the upper portion of the axle and received in the collar, the helical spring including an end portion attached to the collar so that the upper portion of the axle is held tightly by means of the helical spring so as to be rotated when the shaft is pivoted in a direction and that the upper portion of the axle is released from the helical spring so as not to be rotated when the shaft is pivoted in an opposite direction.

3. A resistance device according to claim 2 including a loop formed on the end portion of the spring, an aperture defined in the collar and a first bolt insertable through the aperture defined in the collar and the loop formed on the end portion of the spring aperture defined in the collar thus connecting the collar with the helical spring.

4. A resistance device according to claim 3 wherein the first bolt is in threaded engagement with the housing.

5. A resistance device according to claim 3 including an annular groove defined the upper portion of the axle for receiving a tip of the first bolt.

6. A resistance device according to claim 1 including an adjustment member connected with annular brake disks and the brake linings for adjusting normal forces between the annular brake disks and the brake linings.

7. A resistance device according to claim 6 including a first wedge including a horizontal upper surface and an inclined lower surface, a second wedge including an inclined upper surface and a horizontal lower surface, an aperture defined in the housing, a second bolt inserted through the aperture defined in the housing, a lower one of the brake linings being in contact with the horizontal upper surface of the first wedge, the inclined lower surface of the first wedge being in engagement with the inclined upper surface of the second wedge, the second bolt being in threaded engagement with the housing, a tip of the second bolt being in contact with the second wedge for moving the second wedge in respect to the first wedge when the shaft is rotated in respect to the housing.

8. A resistance device according to claim 7 wherein the first wedge includes an annular configuration.

9. A resistance device according to claim 7 including two channels defined in the inclined lower surface of the first wedge, two channels defined in the inclined upper surface of the second wedge and two bars received in the channels defined in the inclined lower surface of the first wedge and the channels defined in the inclined upper surface of the second wedge.

10. A resistance device according to claim 9 including two channels defined in the horizontal surface of the second wedge and two bars received in the channels defined in the horizontal surface of the second wedge.

11. A resistance device according to claim 1 including a lower cover attached to the housing and a base pivotably connected with the lower cover.

12.. A resistance device according to claim 10 including two apertured lugs projecting downwardly from the lower cover, an apertured protrusion projecting upwardly from the base and a third bolt inserted through the apertured protrusion and the apertured lugs.

13. A resistance device according to claim 10 including a bolt in threaded engagement with the third bolt.

14. A resistance device comprising a housing including an internal surface, a plurality of ribs formed on the internal surface of the housing, an axle including an upper portion and a lower portion received in the housing, a rotation member connected with the upper portion of the axle so that the axle is rotated when the rotation member is rotated in a direction and that the axle is not rotated when the rotation member is rotated in an opposite direction, two straight surfaces formed on the lower portion of the axle, a plurality of annular brake disks each including an internal edge including two straight portions corresponding to the straight surfaces formed on the lower portion of the axle, a plurality of annular positioner each defining a plurality of cutouts in an external edge thereof corresponding to the ribs and a plurality of slots, a plurality of brake linings each received in a corresponding one of the slots defined in each of the annular positioner, wherein the annular positioner and the annular brake disks are alternatively mounted on the lower portion of the axle, the straight portions of the internal edges of the annular brake disks being in engagement with the straight surfaces formed on the lower portion of the axle so that the annular brake disks are rotatable with the axle, the cutouts defined in the linings being in engagement with the ribs formed on the internal surface of the housing so that the linings are retained in position in the housing, whereby there will be frictional forces between the annular brake disks and the brake linings when the axle is rotated.

15. Any novel feature or combination of features disclosed herein.