Background of the Invention
Applicant is aware of several spring devices in the heels or on the soles of shoes for various purposes such as Kells U.S. Pat. No. 2,545,419; Wallach U.S. Pat. No. 2,508,318; and also U.S. Pat. No. 2,555,654; U.S. Pat. No. 413,693; U.S. Pat. No. 1,021,142, and U.S. Pat. No. 1,160,756.
The primary object of this invention is that when the person puts his weight on the heel then a leaf spring is freed to exert force against the ground and thereby assist in the raising of the heel as the weight of the person is shifted toward the sole, means being provided to return the leaf spring to the initial position when the lift is completed. Another object of the invention is to provide such a device for assisting in the lifting of the heel which is compactly arranged in a cavity of the heel.
Brief Description of the Figures
FIG. 1 is a side view of a shoe showing the heel in position before the weight of the person is shifted to the heel of the shoe, the leaf spring being held retracted.
FIG. 2 is a cross-sectional view showing the heel lift in retracted position.
FIG. 3 is a side view showing the heel lift in the extended position.
FIG. 5 is a developed view of the parts of the heel lift on the heel.
Detailed Description
The shoe 1 has a sole 2 and a heel 3. The heel has a cavity 4 therein. A bottom portion of the heel from the cavity toward the rear 6 of the heel is cut away to form a downwardly and rearwardly inclined surface 7. An anchor pin 8 is extended across the cavity 4 transversly of the heel. A spring coil 9 is anchored on the pin 8. A leaf spring 11 extends from the spring coil 9 so biased as to urge the leaf spring 11 away from the inclined surface 7. A complemental heel portion 12 on the leaf spring 11 complements the heel from the inclined surface 7 to its bottom level.
A lever 13 is pivoted on a pin 14 which latter covers the cavity 4 below the anchor pin 8. The pivot pin 14 extends through a boss 16 on the lever 13, bearing face 17 of the boss 16 is engaged by a coil spring 18. The incline of the bearing face 17 and the bias of the coil spring 18 is such as to urge the lever 13 around the pivot 14 against the leaf spring 11 thereby to hold the leaf spring 11 against the inclined heel surface 7, as shown in FIG. 2. The coil spring 18 is nested in a pocket 19 in the side of the cavity 4 opposite the bearing face 17. The lever 13 has thereon a complemental heel strip 21. The forward end of the lever 13 is spaced from the adjacent bottom wall 22 of the heel by a compressible filler 23, such as sponge rubber.
A releasible latching device for the lever 13 includes a finger 24 which extends from the inner end of the bearing face 17 near the top of the boss 16. A pawl 26 is pivoted on a spring pivot 27 and is normally urged by the spring pivot 27 toward the finger 24. The lower face 28 of the pawl 26 forms a cam surface which initially is abutted by the finger 24 as shown in FIG. 2. When the lever 13 is rocked in a clockwise direction viewing FIG. 2 into the position shown in FIG. 4 the finger 24 bears on the cam surface 28 and pushes the pawl 26 away and enters into a keeper recess 29 thereby to be locked in it and hold the lever 13 temporarily in the leaf spring releasing position.
As the leaf spring 11 is released and moves from the position shown in FIG. 2 into the position shown in FIG. 4, thereby to aid in lifting the heel, a releasing mechanism pulls the pawl 26 around the spring pivot 27 so as to release the finger 24 thereby to allow the coil spring 18 to return the lever 13 into the initial locking position shown in FIG. 2.
The release mechanism includes a line 31 one end of which is secured to an ear 32 on the leaf spring 11 the other end of which is secured in a hole 33 of the pawl 26 above the spring pivot 27. The line 31 is played around a guide pulley 34 in the cavity 4. When the leaf spring 11 moves toward the position shown in FIG. 4, the line 31 is pulled downward and rocks the pawl 26 away from the finger 24 and releases the lever 13 which allows the coil spring 18 to return the lever 13 to its initial position bearing against the leaf spring 11. For this purpose the coil spring 18 is considerably stronger than the spring coil 9 of the leaf spring 11 so that the leaf spring 11 can move away from the slanted surface 7 only when the person places his weight on the forward portion of the heel thereby to rock the lever 13 into the position shown in FIG. 4.