This invention relates to a combination of strap and buckle suitable for diving fins.
In the accompanying drawings, FIG. 5 is a perspective view showing one of diving fins 101 disclosed in Japanese Patent Publication No. 1989-38510B as partially broken away and FIG. 6 is a sectional view taken along a line VIxe2x80x94VI in FIG. 5. It should be understood here that, in FIG. 6, the buckle 106 made of hard plastic material is shown in a sectional view and a heel strap 103 made of soft rubber is shown in a side view. This buckle 106 serves to connect the strap 103 to a rear end of a foot pocket 102 and to tighten the strap 103 around a fin wearer""s heel. The buckle 106 comprises a sheath-shaped first coupling member 104 and a second coupling member 105 wherein the first coupling member 104 is mounted on the rear end of the foot pocket 102. The second coupling member 105 has a insert portion 114 releasably attached to the first coupling member 104 and a holding frame mechanism 115 serving to hold the strap 103 draped around a pin 119 provided in the holding frame mechanism 115 as its component. This holding frame mechanism 115 includes movable locking means 120 supported by a shaft 123 and biased by a spring 128 so as to be rotated clockwise as viewed in FIG. 6. The second coupling member 105 is formed on its lower surface with a second locking tooth 124. The strap 103 draped around the pin 119 of the holding frame mechanism 115 is formed on its one surface with a plurality of first locking teeth 121 arranged in longitudinal direction of the strap 103 so that one of these first locking teeth 121 may bear against the second locking tooth 124 in a direction indicated by an arrow 129 in FIG. 6. The second locking tooth 124 is moved off upward from the first locking tooth 121 as the movable locking means 120 is rotated against the biasing effect of the spring 128. Thereupon, the strap 103 may be pulled in the direction indicated by the arrow 129 to move the strap 103 in a direction in which the strap 103 is slackened. Each of the first locking teeth 121 has an inclined rear surface 121A so that the rear surface 121A causes the movable locking means 120 to float as the strap 103 is pulled in the direction opposite to the direction indicated by the arrow 129. In this way, the strap 103 can be moved in the direction in which the strap 103 is tightened.
In the convention combination of buckle 106 and strap 103 as shown in FIGS. 5 and 6, the rectilinear strap 103 is draped around the pin 119 so as to be forcibly flexed in U- or V-shape. The strap 103 normally tends to restore its initial rectilinear state, i.e., tends to move in a direction indicated by an arrow 140 in FIG. 6. Consequently, one of the first locking teeth 121 bears against a rear end 115A of the holding frame mechanism 115 from the right as viewed in FIG. 6 as the strap 103 is pulled in the direction indicated by the arrow 129 and often prevents the strap 103 from smoothly moving in the direction indicated by the arrow 129. Thus, operation of slackening the strap 103 would take much time.
It is an object of this invention to improve the conventional combination of buckle and strap so that the strap can be smoothly moved and slackened without taking much time and labor.
According to this invention, there is provided a combination of buckle and strap for diving fins adapted to couple a heel strap to a foot pocket and at the same time to adjustably tighten the strap around a diver""s heel.
The strap is formed on its one surface a plurality of first locking teeth arranged intermittently in a longitudinal direction of the strap, each of the first locking teeth extending in a transverse direction of the strap so as to leave transversely opposite side edge portions of the strap free from any tooth. The buckle comprises a sheath-shaped first coupling member and a second coupling member releasably engaged with the first coupling member and having front and rear ends, wherein the second coupling member comprises an insert portion formed adjacent the front end so as to be releasably engaged with the first coupling member and a holding frame mechanism formed adjacent the rear end within which the strap is draped around so as to be movable in the longitudinal direction of the strap. The holding frame mechanism includes a movable locking piece pivotally supported by the holding frame mechanism. The movable locking piece has a second locking tooth normally biased by springs to bear against the first locking tooth and thereby to prevent the strap from moving in a direction in which the strap is slackened and pivotally moved upward away from the first locking tooth against the biasing effect of the springs, allowing the strap to move in a direction in which the strap is tightened, as the strap is pulled in the direction in which the strap is tightened. In the vicinity of the rear end, the holding frame mechanism presents an inverted U-shaped section defined by a top portion and a pair of lateral portions depending from transversely opposite side edges of the top portion wherein a pin around which the strap is draped extends between the pair of lateral portions below the top portion and a lower surface of the top portion has transversely opposite side edge portions bears against the strap disposed between the lower surface and the pin so that the transversely opposite side edge portions of the strap extending outside the first locking teeth may slidably move and transversely middle zone of the lower surface of the top portion is hollowed out upward by a dimension deeper than a height of the first locking teeth so that the first locking teeth can move in the longitudinal direction of the strap.