Treadmill with improved adjusting mechanism

#This invention relates to a treadmill and particularly to adjusting mechanisms for adjusting the rotative speed and the slope of an endless belt of the treadmill.

#A machine denoted as a treadmill has been well known and widely used by many people. Today the treadmill is becoming increasingly popular as an exercise device due to the fact that the space for exercise activity in many cities is gradually decreasing. Ideally, this machine forces a person to move his or her legs at a rate which will prevent the person from being thrown off the exercise device. Typical exercise machines, of course, employ a complicated structure; however, such structure is either inaccessible or difficult to manipulate immediately, so as not to fulfill the requirements of the user.

#It is known to provide adjusting mechanisms for adjusting the rotative speed and the slope of an endless belt of the treadmill. One of the known treadmill includes an adjusting mechanism which has a V-belt drive assembly operated by a reversible motor through a gear assembly. The V-belt drive assembly includes a pair of cone-shaped discs, one of the pairs being mounted on an output shaft of a driving motor and the other pair being mounted on a transmission shaft parallel to the output shaft. The pair of the discs mounted on the transmission shaft has a slideable disc which can be moved toward and away from an adjacent fixed disc by the operation of the reversible motor and a telescopic threaded sleeve which is extensible and retractable to move the slideable disc. The transmission shaft is associated operably with the driven shaft of the belt through a complicated gear assembly. The slope adjusting mechanism of this treadmill includes a linkage system which can be adjusted in height through a screw adjustment unit.

#Those objects of this invention will become apparent from the following detailed description of the preferred embodiment in conjunction with the accompanying drawings, wherein:

#FIG. 1 is a perspective view of the preferred embodiment according to this invention;

#FIG. 2 is a perspective view of a speed adjustable mechanism according to this invention;

#FIG. 1 shows this invention as associated with a treadmill 1 having a base frame 2 on which an endless belt 3 is rotatably mounted. The base frame 2 has a pair of integral upright posts 4 secured thereto. An instrument 6 which has a display and a plurality of functions thereon for readily manipulating this machine and instantaneously realizing the status of the user himself, is mounted integrally between the upper ends of the posts 4 and a handle portion 5 is secured thereto.

#FIG. 2 shows a speed adjustable mechanism 10 mounted within the first portion of the base frame 2 for driving the endless belt 3 at a variable speed, including a drive motor 11 having an output shaft 111; a driven shaft 15 associated with the endless belt 3; a speed variable V-belt drive mechanism in connection with the output shaft 111 and the driven shaft 15, the belt drive mechanism 12 including a transmission shaft 123 which is parallel to the output shaft 111 and the drive shaft 15 and which can be displaced laterally, pulleys 112 and 151 mounted respectively on the shafts 111 and 15, two pairs of cone-shaped discs 121 and 122 mounted coaxially on the transmission shaft 123, each of the pairs of discs 121 and 122 having a fixed disc 121' or 122' and a slidable disc 121" or 122" adjacent to the slidable disc of the other discs, the slidable discs 121" and 122" sliding mutually upon displacement of the transmission shaft 123; and means 13 for displacing the transmission shaft 123, including a crank shaft 133 in parallel with the transmission shaft 123, a crank arm 131 interconnecting the transmission shaft 123 and the crank shaft 133, two seats 134 and 135 for mounting the crank shaft 133; a first reversible motor 14 for driving the crank shaft 133, and a gear transmission mechanism interengaging the crank shaft 133 and the first reversible motor 14.

#The gear transmission mechanism includes a first sector gear 132 mounted on the crank shaft 133 and a first worm wheel 143 engaging with the sector gear 132, a gear 142 engaging with a gear 141 mounted on the first reversible motor 14.