1. Fields of the Invention
The invention relates to a coupling for joining connection tubes of an exercise apparatus, and more particularly to a coupling that ensures a great connection strength between both connecting tubes and protects them from being unexpectedly loosened when external forces are applied thereto.
2. Description of the Related Art
It is learned that the main body of the common exercise apparatuses consists of metal tubes that are joined (e.g. welded, clamped, screwed, etc.) either in a vertical or in a horizontal direction. The invention only involves the screwed connection. The screwed connection allows a detachable possibility of the main body of the exercise apparatus for facilitating the packaging and transporting work by minimizing the dimensions of the whole exercise apparatuses. This is common knowledge so that no further descriptions thereto are given hereinafter.
However, the main body of the exercise apparatus is commonly loaded to a great extent. For example, it has to bear the weight of the operator with kicking, pulling, pushing, jumping, running actions. Therefore, the screwed joint strength at the screwed position is very important. Otherwise, the main body of the exercise apparatus could get loose or even be taken apart.
In view of the drawbacks of the structure of the prior art, the inventor of the present invention based on years of experience in the related industry to conduct extensive researches, and finally invented a coupling for joining connection tubes of an exercise apparatus. Therefore, it is a primary object of the invention to employ the corresponding top and bottom coupling members on the connection tubes. The internal diameter of the tube defined by the top and bottom coupling members is substantially greater than the external diameter of the lower connection tube. In this way, the connection tubes can be firmly attached to each other at contact surfaces between the top and bottom coupling members by use of fixing elements. Therefore, an excellent interlocking strength between the connection tubes can be ensured to provide the fixing elements with sufficient resistant ability against all external force.
The accomplishment of this and other objects of the invention will become apparent from the following description and its accompanying drawings of which:
The technical characteristics, features and advantages of the present invention will become apparent from the following detailed description taken with the accompanying drawing.
Referring to FIGS. 1 to 3, a preferred embodiment in accordance with the invention is provided for the vertical attachment of an upper and a lower connection tube 20, 22. As shown in
Referring to
Referring to FIGS. 6 to 7, another preferred embodiment in accordance with the invention is provided for the horizontal attachment of two connection tubes 30, 32. As shown in
Based on the above-mentioned configuration, an excellent connection effect can be ensured no matter which contour (e.g. circular, oval, rectangular, square, polygon) the connection tubes have.
Many changes and modifications in the above-described embodiments of the invention can, of course, be carried out without departing from the scope thereof. Accordingly, to promote the progress in science and the useful arts, the invention is disclosed and is intended to be limited only by the scope of the appended claims.