BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an exercising device which includes at least one actuating grip adapted to be actuated by a user for exercise, and a counteracting force generating member configured to act upon the actuating grip with a counteracting force. Particularly, the actuating grip and the counteracting. force generating. member are connected relative to each other through a tensing member and a power ratio varying member.
2. Description of the Related Art
Exercising devices are now being set up in housing areas in addition to professional fitness centers. Such kinds of exercising devices are particularly used to build and to strengthen different groups of body muscles. Usually, there is a suitable actuating grip in an exercising device, e.g. a pull rod of an exercising device, to which the user applies his/her operating force to work out the muscles of his/her back by attempting to move them against a resisting force. Overcoming of the resisting force gives rise to an actual effect of physical training. The resisting force is attributed to a counteracting force generating member. Conventionally, the counteracting force generating member is exemplified through weights, since, by means of the weights, a counteracting force can be brought about independently of the change in speed and position. In order to accommodate the needs of different users and the training of different groups of muscles, a comparatively large number of weights is required so as to have a sufficiently wide range of adjustments for the resisting forces. In case of the exercising device for household use, this gives rise to a grave disadvantage, because a multiplicity of weights is barely practical not only on the aspect of the expenditure for procurement, but also on the aspect of the costs for transport and storage.
SUMMARY OF THE INVENTION
It is an object of this invention to provide an exercising device as mentioned above, which renders possible a wider range of adjustment for resisting forces.
In accordance with this invention, the exercising device includes at least one movable actuating grip adapted to be actuated by a user for exercise, and a counteracting force generating member configured to act upon the actuating grip with a counteracting force. The actuating grip and the counteracting force generating member are connected relative to each other through a tensing member and a power ratio varying member. The power ratio varying member is a drive wheel unit which includes at least two disc-shaped wheels that have different diameters, that are coaxially coupled to each other, and. that are non-rotatable relative to each other. A coupling unit is further disposed to permit the tensing member to engage a selected one of the disc-shaped wheels.
Some technical terms as used herein are briefly explained as follows:
The term, “drive wheel unit” is directed to a device in which a first rotation movement at an input side thereof is converted into a second rotation movement at an output side thereof The proportional ratio of rotation movements at the input and output sides determines the conversion ratio of the drive wheel unit.
The term, “counteracting force generating member” is directed to a member which impresses on movement of. another element, such as an actuating grip, a force which counteracts the movement of the element. This force can be constant or dependent on the distance covered by, or speed of, the movement of the actuating grip. The counteracting force, albeit unnecessary, can assume a value of zero, when the actuating grip is not moved. In the event of not assuming the value of zero, the counteracting force will press the actuating grip against a striking force which is provided therefor.
The term, “tensing member” means elements which are suitable for transmission of mechanical pulling forces. They can be ropes, for example, belts, chains or the like.
The term, “coupling unit” is directed to a unit which includes two components detachably connected to each other. In a locked position, the components are frictionally connected to each other, or form-locked to each other.
In this invention, the tensing member runs over the drive wheel unit for force transmission. The drive wheel unit includes at least two disc-shaped wheels that are coaxially coupled to each other, and that are non-rotatable relative to each other. Since the disc-shaped wheels have different diameters, the proportional ratio of the diameters thus determines the conversion ratio of the drive wheel unit. A coupling unit is provided to couple the tensing member to the disc-shaped wheels of the drive wheel unit. The tensing member can be coupled to a selected one of the disc-shaped wheels through the coupling unit. Due to the provision of the coupling unit, the tensing member can be desirably coupled to the selected one of the disc-shaped wheels to thereby obtain different conversion ratios. For example, in the event that the tensing member coming from the actuating grip is coupled to the disc-shaped wheel of a smaller diameter, and that the tensing member running towards the counteracting force generating member is coupled to the disc-shaped wheel of a larger diameter, a force-diminishing ratio is obtained based on the actuating force, the strength of which is determined by the proportional ratio of the two diameters. Accordingly, when the coupling is made the other way around, a force-increasing ratio is obtained. Note that, with two disc-shaped wheels, two different proportional ratios can be obtained. Thus, when a larger number of disc-shaped wheels is provided, a larger number of proportional ratios can be achieved. For example, in case of three disc-shaped wheels with different diameters, there are six different proportional ratios available. In this manner, even in the event that a counteracting force generating member by itself, offers merely a few possibilities of adjustment, a fine gradation of counteracting forces which act respectively on the actuating grip, will be available. Such a manner is particularly advantageous in a counteracting force generating member which consists of weights, and which requires only smaller and not so heavy weights. It is however, intended in the present invention to encompass a greater range of forces so as to reach the extreme end of great force on the one hand, while on the other hand, to render a fine gradation of the lower region of smaller forces possible.
Preferably, the coupling unit is configured to be quick releasable. Such a configuration is advantageous when the exchange of the disc-shaped wheels which are respectively coupled to the tensing members through the coupling units, is to be carried out in a simple and rushed manner. With this configuration, the proportional ratio can be easily and conveniently adapted to meet the respective demand.
Preferably, the coupling unit is configured to be form locking. Such a configuration permits a particularly simple and secure fastening of the tensing member to the respective disc-shaped wheel. The form-locking configuration renders possible a particularly quick and secure coupling of the tensing member to: the disc-shaped wheel.
Accordingly, the coupling unit is configured such that, a plug is disposed on one end of the tensing member, and a undercut cavity, which is formed in the circumferential area of the disc-shaped wheel, is accessible externally through a transverse channel. The transverse channel is a channel which is disposed transverse to the pulling direction of the tensing member, i.e., preferably extending in the axial direction. Such a configuration renders possible simple disengagement of the tensing member from the disc-shaped wheel of the drive wheel unit. The tensing member is. pushed into the undercut cavity of the disc-shaped wheel laterally through the transverse channel by means of the plug disposed at the end thereof. Due to the provision of the undercut cavity, the plug can only be removed from the cavity through the transverse channel. In other words, it can not be pulled out of the cavity with the radial pulling forces in the tensing member. As a result of the provision of the coupling unit, aside from ensuring secure coupling of the tensing. member to the disc-shaped wheel, a greater force of pulling is also achieved. While the plug is, preferably configured to be cylindrical, it can also assume other forms, e.g. ball-shaped. A cylindrical shape is advantageous in that the stress of the material due co surface pressing is comparatively small.
Preferably the cavity includes an entry region which is communicated with the transverse channel, and a securing region which is communicated with the entry region in a circumferential direction, and which is configured to accommodate the plug. Such a configuration renders possible sidewise insertion of the plug of the coupling unit into the entry region of the cavity and subsequent shifting into the close-ended securing region through the transverse channel. Due to. this configuration, the plug which is subject to load, is moved out from the entry region and into the securing region so as to be guarded against slipping out of the cavity. With such provision, the coupling unit could also be guarded against unintentional loosening when subjected to sidewise pulling forces. Loosening of the coupling unit is only possible in an unloaded state. At that moment, the plug is moved out from the securing region into the entry region where the plug can be finally removed therefrom through the transverse channel.
Preferably, the disc-shaped wheels are configured to be alienable in sequence. With such a configuration, the number of the available proportional ratios can be increased with the inclusion of additional disc-shaped wheels so that the applicable range of the drive wheel unit can be broadened. As a result, the drive wheel unit can accommodate such an exercise that requires in the lower region of smaller forces quite a number of particularly fine gradations.
Preferably, the drive wheel unit includes three disc-shaped wheels. With such provision, there could be up to six different proportional ratios while obtaining a compact structure of the drive wheel unit.
Preferably, the disc-shaped wheels, especially the outer wheels, are configured to be exchangeable with one another. The exchangeability of the wheels renders possible a feasible application of a single disc-shaped wheel of the drive wheel unit, thereby sparing the costs of production and storage.
Preferably, the disc-shaped wheels are configured to be noncircular, especially ellipsoid. With such provision, the ratio given rise to by the drive wheel unit can vary according to the angular position of the disc-shaped wheel. As a result, the strength of the counteracting force acting upon the actuating grip. is dependent upon the wheel position. This configuration has an advantage in that the stroke of the resultant counteracting force can be regulated by taking into consideration a biophysiological factor, particularly, an anatomical factor. For example, when body joints are. not sufficiently stretched in the initial period of the exercising movement, a comparatively small force is applied thereto so as to treat the joints more gently, whereas in the progressing period of movement of the actuating grip, more counteracting forces can be exerted on the comparatively unloaded joints. Understandably, the diameter of the wheel is preferably selected such that the ellipsoid wheel is only rotated over the actuating route of the actuating grip.
The exact dispositions of the segments 51 and 52 of the tensing member 5 on the drive wheel unit 4 as well as their arrangements are illustrated in detail in FIG. 2 and in FIG. 3. At first, the structure of drive wheel unit 4 is described. The drive wheel unit 4 is exemplified to consist of three disc-shaped wheels 41,42,43. They are disposed on a common shaft 44, which extends into the middle one of the wheels 41,42,43 through a corresponding. opening. The disc-shaped wheels 41,42,43 are coupled to, and are non-rotatable relative to each other by virtue of, in total, three screw bolts 45 which are respectively led to pass through three corresponding through bores in the disc-shaped wheels 41,42,43. The segments 51, 52 of the tensing member 5 are respectively coupled to the disc-shaped wheels 41,42 through the coupling unit 6. In this connection, the segment 51 which comes from the actuating grip 2 is coupled to the disc-shaped wheel 41 which is of a smaller diameter (d) The segment 52 led towards the counteracting force generating member 3 is coupled to the disc-shaped wheel 42 which is of a diameter (D) that is larger than the diameter (d) The proportional. ratio of the diameters D: d determines the. magnitude of the power ratio of the drive wheel unit 4. For example, it runs up to 2:1, 1:1 or 1:2 depending on which one of the segments 51, 52 the disc-shaped wheels 41,42,43 are coupled to.