1. Field of the Invention
The present invention relates to an elastic cord. The present invention also relates to a pull exerciser having such an elastic cord.
2. Description of the Related Art
The elastic cord 3 is substantially hollow and capable of returning to its original length when stretched and then released. Each stop 31 has a width or outer diameter larger than a diameter of the positioning hole 411, preventing the associated end 30 of the elastic cord 3 from disengaging from the associated positioning hole 411 when the elastic cord 3 is stretched. The disengagement-preventing effect is enhanced by the associated sleeve 32 that is made of rubber and that holds the associated end 30 of the elastic cord 3. However, the assembling procedures for the sleeve 32 are troublesome.
In accordance with a first aspect of the present invention, a pull exerciser comprises at least one attachment device, at least one positioning device coupled to the at least one attachment device, and at least one elastic cord. The attachment device includes a handle. The positioning device includes at least one positioning hole. At least one of two ends of the elastic cord is hollow and engaged in the positioning hole. The end of the elastic cord includes an inner section and a turnback section surrounding the inner section. The end of the elastic cord and a distal end portion of the turnback section are engaged in the positioning hole. A stop is mounted in the end of the elastic cord and securely held by the inner section and the turnback section. The stop has an outer diameter larger than a diameter of the positioning hole.
In an example, the positioning device comprises two positioning plates each including at least one positioning hole that is in communication with outside via a reduced opening.
Preferably, the elastic cord is hollow.
Preferably, the turnback section is longer than the stop.
In accordance with a first aspect of the present invention, an elastic cord for a pull exerciser comprises a hollow end. The hollow end includes an inner section and a turnback section surrounding the inner section. A stop is mounted in the hollow end to form a bulge. The stop is securely held by the inner section and the turnback section.
Preferably, the stop is ellipsoidal or cylindrical.
Other objectives, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
In this embodiment, the pull exerciser comprises two positioning devices 5, two attachment devices 6, and at least one elastic cord 71 (three in this example). Each attachment device 6 comprises a handle 62 and a length-adjustable belt 61 extending through the handle 62.
Each positioning device 5 is coupled with an associated attachment device 6 in a position opposite an associated handle 62. Each positioning device 5 includes two positioning plates 51 each having at least one positioning hole 511 (three in this example). Each positioning hole 511 is in communication with outside via a reduced opening 512. An example of the positioning device 5 is disclosed in Applicant's U.S. Pat. No. 6,676,576, the entire contents of which are incorporated herein by reference.
Each elastic cord 71 is substantially hollow and capable of returning to its original length when stretched and then released. Each elastic cord 71 includes two ends 711 and a stretchable intermediate section 712 between the ends 711. In this embodiment, each end 711 of each elastic cord 7 is extended through an associated positioning hole 511 of an associated positioning device 5.
A stop 72 is mounted in each end 711 of each elastic cord 71. Each stop 72 is preferably ellipsoidal or cylindrical. Each stop 72 is inserted into an associated end 711 of the associated elastic cord 71 via an end opening 717 of the associated end 711. Each stop 72 has an outer diameter greater than a diameter of the associated positioning hole 511. Thus, the associated end 711 of the associated elastic cord 71 is bulged and would not disengage from the associated positioning hole 511 after the elastic cord 71 passes through the positioning hole 511.
Referring to
The elastic cords 71 with turnback sections 714 provide excellent resilient holding forces for reliably holding the stops 72 in place without the need of the sleeves 32 required in the conventional design. Disengagement of the stops 72 from the end openings 717 is prevented. The turnback section 714 can be easily obtained by turning the associated end 711 of each elastic cord 71 outward and backward to form a dual-layer section from the point 713.
More specifically,
It is noted that the elastic cord 71 in accordance with the present invention can be used with pull exercisers of any types. For example, the pull exerciser may include only one attachment device (with only one handle) and only one positioning device.
Although specific embodiments have been illustrated and described, numerous modifications and variations are still possible without departing from the essence of the invention. The scope of the invention is limited by the accompanying claims.