Patent Application
20100083793
1. Field of the Invention
The invention relates to a lifting mechanism for an exercise apparatus, and more particularly, to a circular covering cap 13 the portion of which is not subject to force being made of lightweight material while the portion of which is subject to force being made of high strength material.
2. Description of the Related Art
Most of the conventional exercise apparatuses include a lifting mechanism to adjust its inclination relative to a horizontal plane. In order to facilitate the operation thereof, a motor is employed to drive a reduction gearset for imparting rotational motion to a lifting element. In this way, a desired angle is achieved.
The reduction gear of the conventional transmitting and lifting mechanism is completely made of metal by the casting process, thereby considerably increasing the production cost in addition to the increase of weight. In order to avoid the drawbacks, a lifting mechanism 70 disclosed in U.S. Pat. No. 6,964,632 includes a housing 71 accommodating the reduction gear is made of plastic by the injection molding process. A supporting piece 73 is provided at the external side of a through hole 72 and secured by bolts 74 for enhancing the strength of the through hole 72. However, when a driving gear (not shown) disposed within the plastic housing 71 drives a spindle 75 into rotation, a threaded sleeve will generate the torsional type friction acting on the internal wall of the housing 71, thereby leading to damage with fracture. This requires further improvement.
An object of the invention is to provide a lifting mechanism for an exercise apparatus that includes a housing with portion subject to force being made of high strength material. Moreover, the high strength material is applied to the internal wall of the plastic housing in such a way that the internal transmission gear is in contact of the high strength material rather than in contact of the housing. As a result, the plastic housing can achieve the effect of reducing weight. Meanwhile, the strength can be maintained such that no fracture takes place. Furthermore, a prolonged service life is ensured.
In order to achieve the above-mentioned object, a lifting mechanism for an exercise apparatus frame base includes a housing made of lightweight material with a positioning cavity having a through hole. A covering cap having a circular internal rim is integrally formed within the positioning cavity and made by high strength material an injection molding process is performed. The bottom of the covering cap includes an axle hole corresponding to the through hole. The top of the covering cap has an opening with a positioning flange extending outwards. In this way, the drawback that the inside of the conventional plastic housing is easily damaged by the transmission gear can be eliminated. As a result, the weight can be minimized and the strength can be maintained.
The accomplishment of this and other objects of the invention will become apparent from the following descriptions and its accompanying figures of which:
First of all, referring to
The covering cap 13 illustrated in
In order to achieve a problem-free operation of the invention, a transmission unit 20, a motor 30, a transmission rod 40, and a fixing sleeve 50 have to be provided.
The transmission unit 20 includes a reduction gear set 21 and a transmission gear 22 disposed within the housing 10. One end of the transmission gear 22 is positioned within the covering cap 13 while the other end thereof is fixed by the cover plate 12 in place.
The motor 30 is positioned at the external side of the housing 10 for supplying power to the transmission unit 20.
The transmission rod 40 passes through the housing 10 and is engaged with the transmission gear 22. According to the embodiment, the transmission rod 40 is a threaded rod. In other words, the transmission gear 22 is driven by the motor 30 via the reduction gear set 21. Thereafter, the transmission rod 40 is driven by the internal thread of the transmission gear 22 for an axial movement. This is the general mechanic principle so that no further descriptions thereto are given hereinafter.
The fixing sleeve 50 is disposed at the external side of the housing 10 and mounted on one end of the transmission rod 40.
Based on the above-mentioned construction, the lifting mechanism can be employed for adjusting the angle of elevation (see
When the transmission rod 40 is extended or retracted, the pushing force will be transmitted by the end of the transmission gear 22 to the covering cap 13 and the cover plate 12 of the housing 10. According to the invention, the covering cap 13 and the cover plate 12 of the housing 10 subject to the pushing force of the transmission rod 40 are made of high strength material for creating a considerable structural strength to overcome the pushing force generated by the transmission rod 40. Meanwhile, the other portion of the housing 10 that is not subject to force can be made of lightweight material for minimizing the entire weight of the housing 10. As a result, the necessary strength can be maintained to achieve an easy movement. In addition, the material cost can be reduced. Consequently, the lifting mechanism in accordance with the invention has the advantages of reducing the weight and maintaining the necessary strength.
