US1504903A - Artificial foot - Google Patents

Description

Filod May 5, 1924 if 'Y 'fr f *i f S is wedged.

Patented Aug. 12, 1924.

JAMIS F. ROWLEY, 013|* CHICAGO, ILLINOIS.

ARTIFICIAL FOOT.

Application filed May 5, 1924. Serial No. 711,170.

To all whom it may concern.'

Be it known that I, JAMEs F. RowLEY, a citizen of the United States of America, and a resident of `lChicago, county of Cook, and State of Illinois, have invented new and useful improvement in Artificial Feet, of which the following is a specification.

The main objects of this invention are to provide an improved artificial foot; to provide an improved form and arrangement of cushioning means for yieldingly resisting` the relative movements of the articulated parts to as nearly as possible similate the action of the natural foot in absorbing the shocks incident to the tread of the footv and the shifting ofthe weight from one part of the foot to the other during the act of walking or running; to provide a pair of opposing spring cushions normally holding the foot in a natural unleXed position; and to provide a buffer cushion which only acts when the flexure of the foot exceeds the predetermined limit.

An illustrative embodiment of this invention is shown by the accompanying drawings, in which.:

Figure 1 is a sectional elevation of the improved form of a foot showing the position of opposing springs and the bui'ler cushion.

In the specific embodiment herein shown, the foot comprises a leg member or shin section 1 and the foot core 2 articulated thereon by means of a ball-bearing hinge 8 comprising bolts 4 and 5 connected together by a pivot 6 which is `iournaled in ball-bearings.

The shin section 1 is hollowed out so as to provide a tapered socket 7 in which a plug` The plug 8 provides a selflocking support for bolt 4. An angle faced member 9 extends across the bottom of the shin section and coaots with the plug 8 for supporting the bolt 4. The lower face of the base 9,y slopes upwardly/ at substantially the same angle towards the toe and the heel of the foot. The wooden foot core 2 is embedded in a foot form or body 10 made of sponge rubber and conforming to the general shape of the human foot. The upper face of this foot core 2 is substantially horizontal between the hinge and the heel and is chamfered forward of the hinge to form a base for the rubber cushion 12. The lower face of the foot core 2 adjacent to the front is curved at 13 so as to provide a kind of recess or pocket which tends to resist the spreading or creeping of the sponge rubber along the core when the pressure is upon the ball of the foot. The improved cushioning means comprises two spring rubber blocks 14 and 15 andthe spring rubber buffer 12. The spring rubber blocks 14 and 15 'are interposed between the opposite faces of the core 2 and the shin baseV 9 at opposite sides of the hinge. These springs 14 and 15 are formed of firm, live rubber so that while they are capable of yielding` they otter considerable resistance land as soon as the vpressure is relieved .they resume their original form and volume. The spring blocks 14 and 15 are preferably of cylindrical form and the heel block14 extendsI through a hole near the rear end of the foot core 2 and is slightly inclined forwardly at an angle to the vertical. The upper end of this cylindrical block 14 is seated in a recess 16 formed in the under face of the base l plate part 9. The lower end of the spring block 14 is embedded in sponge rubber which forms the heel portion of the foot form 10. These springs 14 and 15 are equal and opposite in action, normallyrestoring, the foot to the unflexedposition and so disposed that the tension required for `fiexure is directly proportional to the angle of flex-` ure and is the same for both heel and toe. The buffer disc 12 is seated in a beveled base formed in the foot core 2 where it is secured against dislodgement. The forward or toe spring block 15 is placed in the opposing relation to the bock 14 by` being seated in recesses in the shin section 1 and the foot section 2 at substantially equivalent distances and angles. At the normal foot position there is provided a clearance between the buffer cushion 12 and the shin section 1, the upper surface of the buffer cushion being formed to coact with the shin section when the toe has been bent upward to a predetermined angular limit.

The two pieces of spring rubber 14 and 15 located between the articulated parts of the foot at opposite sides of their connection serve to yieldingly resist the relative shift-ing of said parts and give a smooth and even resilience which occurs in the normal process of walking. This invention provides a spring buffer which comes into play when any unusual leXure is required and the spring buffer provides for the toe fiexure a shock absorber somewhat equivalent to that provided by the spring block 14 which is carried through the core section and enibedded in the live rubber of the heel. The spring buli'er in operation has lateral eXpansion when lLinder axial compression. The presence of the bufler in the toe section makes it possible to provide a more sensitive restoring action in the adjustmentof the tension of the springs 14 and 15. The action of the three springs as placed, gives a much more natural action of the foot than has heretofore been developed.

Although but one specific embodiment of this invention has been herein shown and described it will be understood that numerous details of the construction shown may be altered or omitted without departing from the spirit of this invention as defined by the following claims.

I claim:

1. An artilicial foot comprising a leg member, a foot core liingedly mounted beloW said leg member, opposed spring rubber cushions comprising a heel cushion and a toe cushion, said heel cushion extending into a recess in said legv member and extending through said foot core, said toe cushion extending" into recesses bearing directly between said leg member, and said foot core and a buifer'cushion secured to said foot core.

n 2. An artificial foot, comprising a shin y section, a foot core hingedly mounted thereon, a foot form supported on and surroundingsaid foot core, a heel block of spring rubber extending through the rear end of said foot core and having the upper end bearing against said shin section and the `lower end embedded in the heel portion of said foot form, a toe block of spring rubber seated in recesses and interposed between said shin section and foot core forwardly of the hinged connection, and a buifer block secured to the upper surface of said foot core.

3. An artificial foot comprising a shin section, a foot core hingedly mounted thereon, a foot form supported on and surrounding said foot core, and a spring rubber buffer mounted on the upper surface of said foot core and spaced away from said shin section, and a pair of opposing spring rubber members seated in recesses forward and rearward of the hinge.

t. An artificial foot, comprising a shin sect-ion, a foot core hingedly mounted there- (on, a foot form supported on and surrounding said foot core, a heel block of spring rubber extending through the rear end of said foot core and having the upper end bearing against said shin section and the lower end embedded in the heel portion of said foot form, a toe block of spring rubber seated in recesses on the toe side of the hinged connection in said shin section and foot core, and a spring rubber buffer fastened to the foot core forwardly of the hinged connection, said core being chamfered to receive said buil'er to secure it against dislodgement but permitting the lateral expansion of said butler when coinpressed axially between said core and said shin section.

Signed at Chicago this 30th day of April, 1924.

JAMES F. ROVVLEY.

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