US 2508318 A
Description (OCR text may contain errors)
May 16, 1950 s. WALLACH RESILIENT HEEL FOR SHOES Filed Jan. 3]., 1949 N0 PRESSURE F34 I? T PPESSU/Pf FULL PRESSURE.
INVENTOR GEORGE WALLACH @W.
Patented May 16, 1956 RESILIENT HEEL FOR SHOES George Wallach, Chapman Camp, British Columbia, Canada Application January 31, 1949, Serial No. 73,765 In Canada December 23, 1948 1 Claim. 1
- The invention relates to a resilient heel for a shoe and is concerned with a heel structure in which a leaf spring is used to provide resilience.
Prior to the invention, the full amount of available resilience in a lea-f spring used to mount the tread surface of a heel structure has not been available to the wearer during the total time that the heel is in contact with the ground or other walking surface. This was because the heel was provided with a conventional flat tread surface which caused maximum leverage of the spring to occur at the beginning of a step when the rear corner of the heel contacted the ground and then suddenly, during completion of the step, as the fiat tread surface came into full contact with the ground, the flat tread surface caused the leverage to be reduced to practically zero so that the heel had no resilience during the remainder of the step.
According to the invention a heel structure is provided in which resilience is available to the wearer both at the beginning of the step and during its completion. The invention provides a heel structure having a leaf type spring to which is attached a curved tread surface extending from the rear of the heel and covering an area which is substantially to the rear of the section of the spring providin resilience. The tread surface of the heel is curved convexly from the rear to the front of the tread surface.
In the preferred form of a heel according to the invention, the leaf spring is formed with a middle resilient section sharply bent at a contained angle of less than 90 from the section which is anchored to the shoe, and the middle section is curved downwardly from the sharp bend until it adjoins the lower section to which the tread surface is attached. It is desirable that a resilient stop block be provided so that when the heel is being used on rough ground the flexing of the spring will be limited to an amount slightly greater than that which occurs during average use of the heel.
In taking a step with a heel according to the invention, the wearer applies pressure to the spring at its rearmost point and then, due to the curvature of the tread surface, the pressure is gradually and progressively transferred in a forward direction along the leaf spring so that the increased weight being applied to the heel is resiliently absorbed by the spring without any jarring to the wearer. Limitation of the area of the tread surface provides the important advantage that the heel is still resilient after full weight of the wearer is applied to it and has the further 5 advantage that the heel can provide a springlike action to the shoe as the weight is being transferred to the other foot for the next step.
The invention will be further described by reference to the attached drawings which illustrate certain embodiments of it, and in which Fig. 1 is a side elevation of part of a shoe showing in section a heel according to the invention,
Fig. 2 is a plan view of the heel shown in Figure 1,
Fig. 3 is a diagrammatic view showing a heel according to the invention during normal use as it makes initial contact with the ground without any substantial amount of pressure yet applied to the shoe,
Fig. 4 is a diagrammatic view similar to that in Figure 3 except that part pressure is being applied to the shoe, and
Fig. 5 is a diagrammatic view similar to Figure 3 except that full pressure is being applied to the shoe.
As shown in Figures 1 and 2, a heel according to the invention may comprise a leaf spring l0 having an upper section I I which is anchored to a shoe I2 by screws I3 and nuts I4 which fasten the upper part II to an anchor plate I5 which is above the sole l6 of the shoe l2. The leaf spring H! has a lower section I! spaced from the upper section I l and resiliently held by a curved middle section l8.
A rubber tread I9 is cemented to the under surface of the lower section l1 and extends about the middle section [8. The tread l9 has a convexly curved tread surface 20 which extends from the rear of the heel to a line 2| which is substantially behind the middle section I8, and at which line the thickness of the tread I9 is reduced so that its surface 22 from the line 2| to the front of the heel does not normally contact the ground or walking surface 24.
In elevation, the leaf spring Ill has the shape of a runner of a sleigh with the middle section l8 bent sharply away from the upper section II and curving downwardly and rearwardly until it adjoins the lower section II. The contained angle between the direction in which the middle section 18 adjoins the upper section II is less than so that the middle section is resilient to forces applied against the lower section H.
A stop block 23 is cemented to the underside of the upper section II at the rear of the heel and extends toward the lower section I! an amount which is so determined that the block 23 will act as a stop to the lower section I! when the lower section is pressed upwardly an amount greater than that which occurs during average use of the shoe [2. The space between the bottom of the block 23 and the lower section I! provides for upward movement of the lower section I! during normal walking.
Figures 3, 4 and 5 of the drawings illustrate three successive stages in the taking of a normal step with the shoe l2 and respectively illustrate,
the conditions of y no pressure, part pressure and full pressure on the shoe I2. In Figure the rearmost corner of the heel is making contact with the ground surface 24 and the sole lfivhas not yet reached the surface 24. The tread surface 20 curves upwardly away from ithezsurface 24 and the contact between the surface 2'4van'd the heel is at the rear only of the tread surface 20.
In Figure 4, part of the weight of the wearer has been transferred to the shoe [2, but the sole [6 is not yet in contactfiwith the surface 24. Due
to the pressure appliedztoetheheel the leaf sprin -ljfithas been forcediupwarclly andthereis aeconsiderableiportion of ithe;tread surface :2Q@in,con
tact-with theg-roundsurface 24 so that the lever s-ar m acting on .=the resilient. section 1.8 ,of ,the leaf spring iii is considerably reduced from that of the vno pressure conditionras shown in @Figure 3.
Thisireduetion in thei n th of the eve arm has taken -.;-p1a. e adua y dueothe c rvatur of the tread surface 20 and by the length of -..t.-h ve am bein reduced the ,r e n 0f ethe spr n 9 is g a a l ad u t a e rdine to the we be n ap i d t the h e 1 2- reduced so that an increase in pressure on the heel due to an unevenness in the walking surface 2 would cause the lower section I! to come into contact with the stop block 23 to prevent damage to the spring l6. However, since the tread surface 20 does not extend beneath the resilient section IS, the heel is still resilient although full ;pressure is "being applied to the shoe l2.
As pressure is removed from the heel during .the transfer of weight from one foot to the other when taking a further step, the leaf spring l0 urges the rear of the shoe upward and forward utilizing,the stored energy in the spring to gently impel the walker forward thereby reducing the fatigue of walking.
What} claim as my invention is:
A heel for a shoe comprising a plate of spring material of substantially the same width as the heel, said plate beingfclded latitudinally upon itself form .an upper section adapted to be anchored to ta t shoe and :a lower section :spaced REEEBQENCES CITED The following references are of record-in the file of this patent:
UNITED STATES PATENTS Number Name Date 357,062 Buch V Y V -Y Feb. 1, 1887 2,e47,603 Snyder .7. Aug. 24, 194B