US3516181A

US3516181A - Protective footgear

Info

Publication number: US3516181A
Application number: US811234A
Authority: US
Inventors: Robert D Jordan
Original assignee: US Department of Navy
Current assignee: US Department of Navy
Priority date: 1959-05-05
Filing date: 1959-05-05
Publication date: 1970-06-23
Anticipated expiration: 1987-06-23

Description

June 23, 1970 R. 0. JORDAN 3,516,181

PROTECTIVE FOOTGEAR Filed May 5. 1959 3 Sheets-Sheet 1 (:2 g INVENTOR. Rwsmr D. JOKDfl/V BY 2/ 25 022; d 41 ae/vcr June 23, 1970 R. D. JORDAN 4 3,516,181

PROTECTIVE FOO'I'GEAR Filed May 5, 1959 3 Sheets-Sheet 5 INVENTOR. )Pwzer .27. Jaw/4w United States Patent 3,516,181 PROTECTIVE FOOTGEAR Robert D. Jordan, Balboa Island, Califi, assignor to the United States of America as represented by the Secretary of the Navy Filed May 5, 1959, Ser. No. 811,234 Int. Cl. A43b 3/10, 3/12; F41h /08 U.S. Cl. 36-75 11 Claims The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

This invention relates to improvements in protective footgear of the type disclosed in pat. application Ser. No. 703,465, filed Dec. 17, 1957 by Frederick J. Lewis, Lawrence R. Holland and John F. Quinlan for Protective Footgear.

Since the introduction of buried charges and booby trapped munitions there has been a need for some method to protect the lower limbs and feet of combatant troops from the blast effect and fragmentation associated with the detonation of all types of minesparticularly small mines which are easily concealed, inexpensive and can be planted in large numbers by relatively unskilled personnel. In general, a small anti-personnel mine (one containing less than 3 ounces of explosive) will sever or avulse the lower extremities. Whether one or both feet are involved depends on several factors, i.e., the amount of weight placed on the charge when detonation is effected, the amount and type of charge, the proximity of the feet to the charge, the depth of concealment, etc. Normally, an individual over or very near the exploding charge will lose at least his foot from the ankle down, and more frequently will suffer the loss of an entire leg.

Typical anti-personnel mines tend to rely upon a blast effect rather than on fragmentation for their destructive properties. Applicants have discovered that by placing a deflecting armored wedge between the foot and the exploding charge the force exerted on the foot can be considerably reduced. The wedge has proved considerably more effective than the same thickness of still air between the sole of the shoe and the foot.

An object of the present invention is to provide protection for the feet and lower limbs.

Another object is to provide a device which will enable troops and mine searching or disposal personnel to traverse mined areas with less difficulty than has formerly been possible.

The advances in orthopedic surgery and treatment can r accomplish seemingly impossible feats providing there is actually some bone, muscle and tissue left to work with. Accordingly, it is a further object of this invention to provide a footgear which will prevent severance of the feet and limbs from the blast force of exploding mines.

Still another object of the invention is to provide a protective device which may be incorporated either in a spe cial armored boot or in an attachment for standard field footwear.

A further object is to provide a reduced area of contact between the ground and the lower surface of the protective footgear.

Yet another object is to stabilize the footing provided by the protective footgear for its wearer despite reduction in the contact area between said footgear and the ground.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

FIG. 1 is a perspective view of a protective footgear, showing a preferred embodiment of the invention;

FIG. 2 is a cut-away, frontal view thereof;

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FIG. 3 is a diagram illustrating the relation of the keel line to the line of the centers of weight of the foot;

FIG. 4 is another diagram illustrating the relation of the keel line to the line of the centers of weight of the foot;

FIG. 5 is a diagram illustrating the manner in which the contour of the keel line can be determined;

FIG. 6 is a perspective Wiew of the footgear as it appears 1n use;

FIGS. 7 and 8 are perspective views from the side and front, respectively, of the locking cylinder and the front loop employed with the footgear; and

FIG. 9 is a cross-sectional view of the bottom of a wedge illustrating one particular type of wedge construction.

Similar numerals refer to similar parts throughout the several views.

It has been found that stability can be improved in protective footgear of the platform type exemplified in U.S. patent application Ser. No. 703,465, filed Dec. 17, 1957, and now abandoned. This improvement in stability permits the elimination of most of the material of the supporting hull previously located exteriorly of the wedge, as well as reduction of the area of contact between the protective footgear and the ground.

The appearance of the improved protective footgear is shown generally in FIG. 1. The armored wedge 20 fits into and is supported by a longitudinal support member 22. As seen in FIG. 2, the cross-section of the wedge 20' is triangular in shape, the angle between the outer surfaces of the wedge sides ranging from forty-five to one hundred degrees and the bottom of the wedge 20 fitting into a complementarily shaped slot 21 running along the top of the support member 22. The support member 22, which can be made of rubber, is rectangular in cross-section and preferably treaded on the substantially flat bottom surface 23 for better traction. The wedge 20 is filled with an acoustic filler 24, such as Dylite, which dampens and attenuates shocks transmitted through the sides of the wedge 20.

The width of the supporting member 22 need be as little as one-quarter to one-third of the width of the shoe platform 26 of the protective footgear. Reduction in contact area between the support member 22 and the ground is made possible by improving the stability features of the footgear. This reduction in contact area permits elimination of the hull, the latter heretofore being necessary to provide sufficient stability for the wearer of the footgear. Elimination of the hull constitutes a distinct advantage since it reduces the weight of the footgear, provides less material to be blown away as secondary missiles, increases ballistic efficiency (a given weight of explosive causes less acceleration of the footgear), simplifies design, and reduces cost. Furthermore, reduction in the contact area of the support member and the ground reduces the probability of contacting the triggering mechanism of an explosive device.

Improvement in stability is elfectuated in the following ways:

(1) The location of the keel line (or ridge line) of the wedge is optimized for the prevention of the tendency of the ankle to turn out;

(2) The keel line is contoured to facilitate normal foot motion while the wearer is walking or running;

(3) A cross-over strap and an ankle-brace-and-legclamp are employed; and

(4) The platform 26 of the wedge 22 is contoured to complement the shape of the bottom surface of the wearers shoe so that slippage between the shoe and the protective footgear is reduced.

FIG. 3 shows the bones of the right foot and their spatial relation to the sole of a shoe and the top of the protective footgear. The center-of-weight line 28 of the foot is the line joining the center of weight on the ball of the foot 30, which lies at the front end of the metatarsal bone of the second toe, and the center of weight on the heel 32, which lies on the tuberosity of the calcaneus. To correct for the tendency of the angle to turn outward, the keel line 34 of the wedge 20 is offset so that the keel line 34 lies about one quarter of an inch outwardly of the center-of-weight line 28 at the center of weight on the heel 32 (along line BB). FIG. 4 illustrates these relations in a front view of the foot and the protective footgear.

'FIG. illustrates the manner in which the proper contour of the keel line 34 is obtained. Optimum contour of the keel line EBDF and the optimum distance between foot and keel line is based on two radii AB 33 and CD 35. A ball-of-foot radius AB 33 of about five inches in length is swung from the center of weight on the ball of the foot 30 (or, in other words, from the axis of rotation which exists at the junction of the metatarsal and the second bone of the second toe), and a heel radius CD 35 of about five inches in length is swung from the axis of rotation C about which the process of the tuberosity of the calcaneus rotates during the normal walking process. The portion of the keel line between the back of the footgear and line AA (EDB) is a line tangent to the arcs generated by the two radii AB and CD. The portion of the keel line forward of line AA (BF) is partially the arc of a circle developed by radius AB and partially a curve shaped to meet the platform 26 of the wedge 20 at point F, the curve being shaped to permit normal foot motion while walking or running.

FIG. 5 also indicates how the shoe platform 26 of the wedge 22 is contoured to compensate for the curve of the sole of the wearers shoe and to provide a depressed portion in which and against which the heel of the shoe rests. The contouring of the shoe platform 26 eliminates much of the slippage which might otherwise occur between the sole of the foot and the platform.

An ankle-brace-and-foot-clamp 36 comprising a pair of vertical braces 38, preferably of metal such as aluminum or steel, a roughly semicircular band 40, preferably of metal, and a strap 42 which loops around the band 40 and is drawn through a pair of holes 44 near the front edges of the band 40, is provided, as shown in FIG. 1. The lower ends of the vertical braces 38 can be welded to the sides of the wedge 20, which extend up beyond the shoe platform 26 along the heel region. The upper ends of the braces 38 can be welded to the band 40. The strap 42 bears some type of locking device, such as a buckle, at its ends. The ankle-brace-and-foot-clamp 36 serves to provide an additional safeguard against the tendency of the ankle to turn outward and an additional means providing secure linkage between the foot and the protective footgear.

FIG. 6 shows the protective footgear strapped to a wearers foot.

The cross-over strap 44 consists of two sections 45, the front end of each section passing through a slot 46 near the front of the footgear, the slot 46 being formed by the extension of a metal loop 48 above the upper edge of the side of the wedge 20. The end of the strap 45 is riveted to a small locking cylinder 50, which fits over the part of the upper surface of the sole of the wearers shoe which projects past the toe cap leather. The cylinder 50 forces the sole into secure linkage with the platform 26 of the protective footgear when the strap 45 is pulled tight.

The strap 45 passes over the toe cap and vamp sections of the shoe to the opposite side, where it is passed through a slot 52 formed by the extension of another metal loop 54 above the upper edge of the side of the wedge 20. This second metal loop 54 extends above the wedge 20 near the location of the front edge of the heel of the wearers shoe. The slot 52 is tilted forward to some extent whereas the front slot 46 is tilted backward to some extent. The other end of the strap 45 bears one section of a locking device 56, such as a buckle, the complementary section of the locking device 56 being borne 'by the corresponding end of the other section of crossover strap 45. Details of the front loop 48 and slot 46, the manner in which the strap 45 passes through the front loop 48, and the small locking cylinder 50 can be seen in FIGS. 7 and 8.

The wedge 22 employed in this inventive embodiment can comprise two sections as shown in FIG. 2 and FIG. 4. Here the upper section 58, which can be fabricated from aluminum, fits into a lower section 60, which is made of a metal such as steel to minimize blast effects.

An alternate method of fabrication of the wedge 20 is illustrated in FIG. 9. Here tWo steel sections 62 and 64, each of which has a long side and a short side, are welded together. The short side of each section is adjacent to the long side of the other section.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

I claim:

1. Protective gear for the foot comprising, in combination: a substantially horizontal platform for supporting the sole of a foot, the area of said platform being somewhat larger than the area of such sole; a wedge member, the sides of said wedge member supporting and extending convergingly downward from said platform to form a longitudinal ridge line, the angle between the outer surfaces of the wedge sides ranging from 45 to degrees; and a longitudinal support member having an upper surface formed with a longitudinal slot therein and a substantially flat lower surface, the ridge line and lower portion of said wedge fitting into said slot and thus being supported in an upright position by said support member, the width of said lower surface being approximately one fourth to one third the Width of said platform.

2. A device of the type set forth in claim 1, wherein a vertical projection of said ridge line intersects the line of centers of weight of the foot at the center of weight on the ball of the foot and lies proximate but outside said line of centers of weight at the center of weight on the heel of the foot.

3. A device of the type set forth in claim 1, wherein the fore-and-aft contour of said ridge line is determined by the line tangent to the arcs formed by swinging radii approximately five inches in length from the axis about which the process of the tuberosity of the calcaneus rotates during the normal walking motion of a foot which rests upon said footgear and from the center of weight on the ball of said foot, the fore part of the latter are being gradually extended to meet the vertical portion of the ridge line which extends downwardly along the forepart of said protective gear.

4. A device as set forth in claim 1, including a securing device for the front part of the foot, said securing device comprising two pairs of loops, one loop of each pair being located on the upper edge of one side of said Wedge member near the positions of the metatarsal bone of the big toe and the ankle, respectively, of said foot, and the other loop of each pair being located at the same positions on the upper edge of the other side of said wedge member, a pair of straps, each extending from the front loop on one side of said wedge member across said foot, through the rear loop on the other side of said wedge member and back to the midsection of the instep of said foot, means for securing each of the front portions of said straps relative to its associated front loop, and means for fastening together the rear ends of said straps upon the instep of said foot so that said straps force said foot into tight linkage with said platform.

5. Protective gear for the foot comprising, in combination: a substantially horizontal platform for supporting a foot, the area of said platform being somewhat larger than the area of the sole of said foot; a wedge member, the sides of said wedge member supporting and extending convergingly downward from said platform to form a longitudinal ridge line, the angle between the outer surfaces of the wedge sides being between 45 and 100 degrees, a vertical projection of said ridge line intersecting the line of centers of weight of the foot at the center of weight on the ball of the foot and lying proximate and outside said line of centers of weight at the center of weight on the heel of the foot, the fore-and-aft contour of said ridge line being determined by the line tangent to the arcs formed by swinging a radius approximately 5 inches in length from the axis about which the process of the tuberosity rotates during the normal walking motion of a foot which rests upon said footgear and from the center of weight on the ball of said foot, the forepart of the latter are being gradually extended to meet the vertical portion of the ridge line which etxends downwardly along the forepart of said protective footgear; and a longitudinal support member substantially rectangular in cross-section and having a longitudinal slot in its upper surface into which the ridge and lower portion of said wedge member fits, said wedge member being supported in an upright position by said support member, the width of said support member being approximately one quarter to one-third the width of said platform.

6. Protective gear for the foot comprising, in combination: a substantially horizontal latform for supporting a foot, the area of said platform being roughly similar in shape but extending somewhat beyond the area of the sole of said foot on all sides; a wedge member, the sides of said wedge member supporting and extending convergingly downward from said platform to form a longitudinal ridge, the angle between the outer surfaces of the wedge sides being between 45 and 100 degrees, said wedge member being filled with filler material adapted to attenuate shock transmitted through the wedge sides, the latter being fabricated from a material resistant to penetration by blast-impelled metallic fragments; and a longitudinal support member having an upper surface formed with a longitudinal slot therein and a substantially fiat lower surface, the ridge and lower portion of said wedge member fitting into said slot and thus being supported in an upright position by said support member, the width of said lower surface being approximately one-fourth to one-third the width of said platform.

7. A device as set forth in claim 6, wherein the vertical projection of said ridge is a line which intersects the line of centers of weight of the foot at the center of weight on the ball of the foot and lies proximate and outside of said line of centers of weight at the center of weight on the heel of the foot.

8. A device of the type set forth in claim 6, wherein the fore-and-aft contour of said ridge is determined by the line tangent to the arcs formed by swinging radii approximately 5 inches in length from the axis about which the process of the tuberosity of the calcaneus rotates during the normal walking motion of a foot which rests upon said footgear and from the center of weight on the ball of said foot, the forepart of the latter arc being gradually extended to meet the vertical portion of the ridge which extends downwardly along the forepart of said protective gear.

9. A device as set forth in claim 6, including a securing device for the front part of the foot, said securing device comprising two pairs of loops, one loop of each pair being located on the upper edge of one side of said wedge member near the positions of the metatarsal bone of the 'big toe and the ankle, respectively, of said foot, and the other loop of each pair being located at the same positions 0n the upper edge of the other side of said wedge member, a pair of straps, each extending from the front loop on one side of said wedge member across said foot, through the rear loop on the other side of said wedge member and back to the mid-section of the instep of said foot, means for securing each of the front portions of said straps relative to its associated front loop, and means for fastening together the rear ends of said straps upon the instep of said foot so that said straps force said foot into tight contact with said platform.

10. Protective gear for the foot comprising, in combination: a substantially horizontal platform for supporting a foot, the area of said platform being roughly similar in shape but extending somewhat beyond the area of the sole of said foot on all sides; a wedge member, the sides of said wedge member supporting and extending convergingly downward from said platform to form a longitudinal ridge, the angle between the outer surfaces of the wedge sides being between 45 and degrees, said wedge member being filled with filler material adapted to attenuate shock transmitted through the wedge sides, the latter being fabricated from a material resistant to penetration by blast-impelled metallic fragments, the vertical projection of said ridge being a line which intersects the line of centers of weight of the foot at the center of weight on the ball of the foot and which lies proximate and outside of said line of centers of weight at the center of weight on the heel of the foot, the fore-and-aft contour of said ridge being determined by the line tangent to the arcs formed by swinging a radius approximately 5 inches in length from the axis about which the process of the tuberosity of the calcaneus rotates during the normal Walking motion of a foot which rests upon said footgear and from the center of weight on the ball of said foot, the forepart of the latter are being gradually extended to meet the vertical portion of the ridge which extends downwardly along the forepart of said protective gear; and a longitudinal support member having an upper surface formed with a longitudinal slot therein and a substantially flat lower surface, the ridge and lower portion of said wedge member fittting into said slot and thus being supported in an upright position by said support member, the width of said lower surface being approximately one-fourth to one-third the width of said platform.

11. A device as set forth in claim 10, including a securing device for the front part of the foot, said securing device comprising two pairs of loops, one loop of each pair being located on the upper edge of one side of said wedge member near the positions of the metatarsal bone of the big toe and the ankle, respectively, of said foot, and the other loop of each pair being located at the same positions on the upper edge of the other side of said wedge member, a pair of straps, each extending from the front loop on one side of said wedge member across said foot, through the rear loop on the other side of said wedge member and back to the mid-section of the instep of said foot, means for securing each of the front portions of said straps relative to its associated front loop, and means for fastening together the rear ends of said straps upon the instep of said foot so that said straps force said foot into tight linkage with said platform.

References Cited UNITED STATES PATENTS D. 35,490 12/1901 Hatheway 36-72 XR 1,310,137 7/1919 Sadowsky 367.5 XR 2,507,991 5/1950 Neal 36-l 2,519,458 8/1950 Hall 36-75 BENJAMIN A. BORCHELT, Primary Examiner C. T. JORDAN, Assistant Examiner U.S. Cl. X.R. 361l.5; 89-36

Claims

1. PROTECTIVE GEAR FO THE FOOT COMPRISING, IN COMBINATION: A SUBSTANTIALLY HORIZONTAL PLATFORM FOR SUPPORTING THE SOLE OF A FOOT, THE AREA OF SAID PLATFORM BEING SOMEWHAT LARGER THAN THE AREA OF SUCH SOLE; A WEDGE MEMBER, THE SIDES OF SAID WEDGE MEMBER SUPPORTING AND EXTENDING CONVERGINGLY DOWNWARD FROM SAID PLATFORM TO FORM A LONGITUDINAL RIDGE LINE, THE ANGLE BETWEEN THE OUTER SURFACES OF THE WEDGE SIDES RANGING FROM 45 TO 100 DEGREES; AND A LONGITUDINAL SUPPORT MEMBER HAVING AN UPPER SURFACE FORMED WITH A LONGITUDINAL SLOT THEREIN AND A SUBSTANTIALLY FLAT LOWER SURFACE, THE RIDGE LINE AND LOWER PORTION OF SAID WEDGE FITTING INTO SAID SLOT AND THUS BEING SUPPORTED IN AN UPRIGHT POSITION BY SAID SUPPORT MEMBER, THE WIDTH OF SAID LOWER SURFACE BEING APPROXIMATELY ONE FOURTH TO ONE THIRD THE WIDTH OF SAID PLATFORM.